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<channel>
	<title>engineering &amp;laquo; WordPress.com Tag Feed</title>
	<link>http://wordpress.com/tag/engineering/</link>
	<description>Feed of posts on WordPress.com tagged "engineering"</description>
	<pubDate>Sun, 27 Jul 2008 09:31:22 +0000</pubDate>

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<item>
<title><![CDATA[Information Please...]]></title>
<link>http://secretengineer.wordpress.com/?p=44</link>
<pubDate>Sun, 27 Jul 2008 01:50:51 +0000</pubDate>
<dc:creator>patrick</dc:creator>
<guid>http://secretengineer.wordpress.com/?p=44</guid>
<description><![CDATA[
I am now on an information hunt and mass-consumption on anything and everything PIC32.  Since I wil]]></description>
<content:encoded><![CDATA[<p style="text-align:center;"><a href="http://www.mypic32.com/web/guest/profiles?profileID=27882#"><img class="size-full wp-image-42 aligncenter" src="http://secretengineer.wordpress.com/files/2008/07/2511256771_cba7a71337.jpg" alt="" width="500" height="62" /></a></p>
<p>I am now on an information hunt and mass-consumption on anything and everything PIC32.  Since I will be building an HTTP server that will communicate wirelessly with the WWW, I also need authentication and encryption algorithms and 802.15.4 data and code examples.</p>
<p>In beginning to think of hardware for this problem, my main concerns are going to be size, power consumption (using solar if possible for the objects where this makes sense), and usability.</p>
<p>In amassing so much information, it becomes critical to logically organize the structure of this data... creating some kind of online library and index.  Maybe Google docs?  Tumblr? Pownce? (indexing is important so maybe those last two would not work so well.)  If I dig, I can probably find an online repository or application that allows for this.</p>
<p>Also, the competition wants video documentary and extensive blogging for the next phase, so I will be using my secretengineer account on youtube finally for my own stuff as opposed to just favorites.</p>
<p>I am also setting up a nice lab here in my studio dedicated for the hardware and software development process.  Pix coming.</p>
<p>And finally, as part of the end-user experience, I have begun to create a Ning-based site that is called <a href="http://mythings.ning.com/" target="_blank">MyThings</a> (currently in alpha and by invite only.  I will post when it goes live - I anticipate within two weeks or so.) that will be the prototype location on the internet where the embedded web servers will feed their data and information as well as serve as the link interface to the objects themselves.</p>
<p>Woo Hoo.</p>
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<item>
<title><![CDATA[Complete microwave planning online with Gmaps and SRTM3 height data]]></title>
<link>http://steveyoung.wordpress.com/?p=73</link>
<pubDate>Sat, 26 Jul 2008 20:31:11 +0000</pubDate>
<dc:creator>steveyoung</dc:creator>
<guid>http://steveyoung.wordpress.com/?p=73</guid>
<description><![CDATA[You no longer need to buy an expensive Microwave Link Planning Tool to plan microwave links, can now]]></description>
<content:encoded><![CDATA[<p>You no longer need to buy an expensive Microwave Link Planning Tool to plan microwave links, can now plan microwave radio links from scratch online by using my Google Maps Microwave Link Planning Tool.  First go to the line of sight tool at <a href="http://members.chello.at/stephen.joung/indexDistanceElevation.html">http://members.chello.at/stephen.joung/indexDistanceElevation.html<br />
</a> where you can enter the Site-A and Site-B by entering addresses, coordinates or simply by clicking on the map. You can zoom in and out with the mouse wheel or by using the controls top left. A new feature is that the site will remember you (if you enable cookies) and the next time you visit the maps will be set to the area and zoom level that you were last at. You can switch between maps, satellite and terrain views witht the control top right. After you have selected the A and B sites the tool will calculate the coordinates, bearing, distance etc. and also gather the height data for the link which it displays as a path profile. You can click on the path profile to display it in a separate window and print it out. You can raise the antenna heights until you achieve line of sight. When you are satisfied with a link you can click on the export button and the link is exported to the <a href="http://members.chello.at/stephen.joung/indexMW_Distance20.html">link engineering tool</a>, where you can set the antenna sizes, frequency band, transmit power etc until you achieve the required availability. You can then print out a link budget for the link.</p>
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<item>
<title><![CDATA[The Missing Secrets Of Nikola Tesla]]></title>
<link>http://theelectricalengineer.wordpress.com/?p=16</link>
<pubDate>Sat, 26 Jul 2008 20:19:46 +0000</pubDate>
<dc:creator>theelectricalengineer</dc:creator>
<guid>http://theelectricalengineer.wordpress.com/?p=16</guid>
<description><![CDATA[I&#8217;ve noticed that many of the visitors of my blog were interested in the life of the great inv]]></description>
<content:encoded><![CDATA[<p>I've noticed that many of the visitors of my blog were interested in the life of the great inventor <span style="color:#00ff00;"><strong>Nikola Tesla</strong></span>, <strong>i've also noticed no one bothered to write a comment !!! :-(</strong></p>
<p>So while i was on the net i found an interesting documentary on the <em>The Missing Secrets Of Nikola Tesla</em> on Google Video. It's very interesting. Just click on the link:</p>
<p><a title="The Missing Secrets Of Nikola Tesla" href="http://video.google.com/videoplay?docid=2188562935002257117" target="_blank"><strong><span style="color:#ff0000;">The Missing Secrets Of Nikola Tesla</span></strong></a></p>
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</item>
<item>
<title><![CDATA[Design Of Hoisting Arrangement Of E.O.T. Crane]]></title>
<link>http://rparmanik.wordpress.com/?p=5</link>
<pubDate>Sat, 26 Jul 2008 14:30:24 +0000</pubDate>
<dc:creator>rajendra Parmanik</dc:creator>
<guid>http://rparmanik.wordpress.com/?p=5</guid>
<description><![CDATA[
&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-||C R A N E S||&#8212;]]></description>
<content:encoded><![CDATA[<p>
<strong>-------------------------------&#124;&#124;C R A N E S&#124;&#124;------------------------------</strong><br />
A crane is a mechanical lifting device equipped with a winder, wire ropes and sheaves that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a human. Cranes are commonly employed in the transport industry for the loading and unloading of freight; in the construction industry for the movement of materials; and in the manufacturing industry for the assembling of heavy equipment.</p>
<p><strong>----------------------------------------&#124;&#124;Overview&#124;&#124;-------------------------------------</strong><br />
The first cranes were invented by the Ancient Greeks and were powered by men or beasts-of-burden, such as donkeys. These cranes were used for the construction of tall buildings. Larger cranes were later developed, employing the use of human tread wheels, permitting the lifting of heavier weights. In the High Middle Ages, harbour cranes were introduced to load and unload ships and assist with their construction – some were built into stonne towers for extra strength and stability. The earliest cranes were constructed from wood, but cast iron and steel took over with the coming of the Industrial Revolution.<br />
For many centuries, power was supplied by the physical exertion of men or animals, although hoists in watermills and windmills could be driven by the harnessed natural power. The first 'mechanical' power was provided by steam engines, the earliest steam crane being introduced in the 18th or 19th century, with many remaining in use well into the late 20th century. Modern cranes usually use internal combustion engines or electric motors and hydraulic systems to provide a much greater lifting capability than was previously possible, although manual cranes are still utilized where the provision of power would be uneconomic.<br />
Cranes exist in an enormous variety of forms – each tailored to a specific use. Sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes, used for constructing high buildings, and the largest floating cranes, used to build oil rigs and salvage sunken ships.</p>
<p><strong>------------------------------------&#124;&#124;History of cranes&#124;&#124;-----------------------------</strong>-<br />
The cranes have found many uses since the beginning of the history, and the history of cranes has come across since then. The Greek were the first people to use cranes for doing the lifting jobs. After this many other peoples like the Roman, the Chinese etc used the cranes and made many changes to the existing design of that time.</p>
<ul>
&#124;&#124;Ancient Greek cranes&#124;&#124;</ul>
<p>The crane for lifting heavy loads was invented by the ancient Greeks in the late 6th century BC.[1] The archaeological record shows that no later than c.515 BC distinctive cuttings for both lifting tongs and Lewis irons begin to appear on stonne blocks of Greek temples. Since these holes point at the use of a lifting device, and since they are to be found either above the centre of gravity of the block, or in pairs equidistant from a point over the centre of gravity, they are regarded by archaeologists as the positive evidence required for the existence of the crane.[1]<br />
The introduction of the winch and pulley hoist soon led to a widespread replacement of ramps as the main means of vertical motion. For the next two hundred years, Greek building sites witnessed a sharp drop in the weights handled, as the new lifting technique made the use of several smaller stonnes more practical than of fewer larger ones. In contrast to the archaic period with its tendency to ever-increasing block sizes, Greek temples of the classical age like the Parthenon invariably featured stonne blocks weighing less than 15-20 tons. Also, the practice of erecting large monolithic columns was practically abandoned in favour of using several column drums.<br />
Although the exact circumstances of the shift from the ramp to the crane technology remain unclear, it has been argued that the volatile social and political conditions of Greece were more suitable to the employment of small, professional construction teams than of large bodies of unskilled labour, making the crane more preferable to the Greek polis than the more labour-intensive ramp which had been the norm in the autocratic societies of Egypt or Assyria.[2]<br />
The first unequivocal literary evidence for the existence of the compound pulley system appears in the Mechanical Problems (Mech. 18, 853a32-853b13) attributed to Aristotle (384-322 BC), but perhaps composed at a slightly later date. Around the same time, block sizes at Greek temples began to match their archaic predecessors again, indicating that the more sophisticated compound pulley must have found its way to Greek construction sites by then.</p>
<ul>
&#124;&#124;Ancient Roman cranes&#124;&#124;</ul>
<p>The heyday of crane in ancient times came under the Roman Empire, when construction activity soared and buildings reached enormous dimensions. The Romans adopted the Greek crane and developed it further. We are relatively well informed about their lifting techniques thanks to rather lengthy accounts by the engineers Vitruvius (De Architectura 10.2, 1-10) and Heron of Alexandria (Mechanica 3.2-5). There are also two surviving reliefs of Roman tread wheel cranes offering pictorial evidence, with the Haterii tombstonne from the late first century AD being particularly detailed.<br />
The simplest Roman crane, the Trispastos, consisted of a single-beam jib, a winch, a rope, and a block containing three pulleys. Having thus a mechanical advantage of 3:1, it has been calculated that a single man working the winch could raise 150 kg (3 pulleys x 50 kg = 150), assuming that 50 kg represent the maximum effort a man can exert over a longer time period. Heavier crane types featured five pulleys (Pentaspastos) or, in case of the largest one, a set of three by five pulleys (Polyspastos) and came with two, three or four masts, depending on the maximum load. The Polyspastos, when worked by four men at both sides of the winch, could already lift 3000 kg (3 ropes x 5 pulleys x 4 men x 50 kg = 3000 kg).<br />
 In case the winch was replaced by a treadwheel, the maximum load even doubled to 6000 kg at only half the crew, since the treadwheel possesses a much bigger mechanical advantage due to its larger diameter. This meant that, in comparison to the construction of the Egyptian Pyramids, where about 50 men were needed to move a 2.5 ton stonne block up the ramp (50 kg per person), the lifting capability of the Roman Polyspastos proved to be 60 times higher (3000 kg per person).<br />
However, numerous extant Roman buildings which feature much heavier stonne blocks than those handled by the Polyspastos indicate that the overall lifting capability of the Romans went far beyond that of any single crane. At the temple of Jupiter at Baalbek, for incidence, the architraves blocks weigh up to 60 tons each, and the corner cornices blocks even over 100 tons, all of them raised to a height of ca. 19 m above the ground. In Rome, the capital block of Trajan's Column weighs 53.3 tons which had to be lifted at a height of ca. 34 m.<br />
It is assumed that Roman engineers accomplished lifting these extraordinary weights by two measures: First, as suggested by Heron, a lifting tower was set up, whose four masts were arranged in the shape of a quadrangle with parallel sides, not unlike a siege tower, but with the column in the middle of the structure (Mechanica 3.5). Second, a multitude of capstans were placed on the ground around the tower, for, although having a lower leverage ratio than treadwheels, capstans could be set up in higher numbers and run by more men (and, moreover, by draught animals).[7] This use of multiple capstans is also described by Ammianus Marcellinus (17.4.15) in connection with the lifting of the Lateranense obelisk in the Circus Maximus (ca. 357 AD). The maximum lifting capability of a single capstan can be established by the number of lewis iron holes bored into the monolith. In case of the Baalbek architrave blocks, which weigh between 55 and 60 tons, eight extant holes suggest an allowance of 7.5 ton per lewis iron, that is per capstan. Lifting such heavy weights in a concerted action required a great amount of coordination between the work groups applying the force to the capstans.</p>
<ul>
&#124;&#124;Mechanics and operation&#124;&#124;</ul>
<p>In contrast to modern cranes, medieval cranes and hoists - much like their counterparts in Greece and Rome- were primarily capable of a vertical lift, and not used to move loads for a considerable distance horizontally as well. Accordingly, lifting work was organized at the workplace in a different way than today. In building construction, for example, it is assumed that the crane lifted the stonne blocks either from the bottom directly into place,[or from a place opposite the centre of the wall from where it could deliver the blocks for two teams working at each end of the wall.<br />
Additionally, the crane master who usually gave orders at the treadwheel workers from outside the crane was able to manipulate the movement laterally by a small rope attached to the load. Slewing cranes which allowed a rotation of the load and were thus particularly suited for dockside work appeared as early as 1340.While ashlar blocks were directly lifted by sling, lewis or devil's clamp (German Teufelskralle), other objects were placed before in containers like pallets, baskets, wooden boxes or barrels.<br />
It is noteworthy that medieval cranes rarely featured ratchets or brakes to forestall the load from running backward. This curious absence is explained by the high friction force exercised by medieval treadwheels which normally prevented the wheel from accelerating beyond control.</p>
<ul>
&#124;&#124;Harbor cranes&#124;&#124;</ul>
<p>Beyond the modern warship stands a crane constructed in 1742, used for mounting masts to largesailing vessels.<br />
According to the “present state of knowledge” unknown in antiquity, stationary harbor cranes are considered a new development of the Middle Ages. The typical harbor crane was a pivoting structure equipped with double treadwheels. These cranes were placed docksides for the loading and unloading of cargo where they replaced or complemented older lifting methods like see-saws, winches and yards.<br />
Two different types of harbor cranes can be identified with a varying geographical distribution: While gantry cranes which pivoted on a central vertical axle were commonly found at the Flemish and Dutch coastside, German sea and inland harbors typically featured tower cranes where the windlass and treadwheels were situated in a solid tower with only jib arm and roof rotating. Interestingly, dockside cranes were not adopted in the Mediterranean region and the highly developed Italian ports where authorities continued to rely on the more labor-intensive method of unloading goods by ramps beyond the middle Ages.<br />
Unlike construction cranes where the work speed was determined by the relatively slow progress of the masons, harbor cranes usually featured double treadwheels to speed up loading. The two treadwheels whose diameter is estimated to be 4 m or larger were attached to each side of the axle and rotated together.[11] Today, according to one survey, fifteen treadwheel harbor cranes from pre-industrial times are still extant throughout Europe.]Beside these stationary cranes, floating cranes which could be flexibly deployed in the whole port basin came into use by the 14th century.</p>
<ul>
&#124;&#124;Mechanical principles&#124;&#124;</ul>
<p>There are two major considerations that are taken into account in the design of cranes. The first is that the crane must be able to lift a load of a specified weight and the second is that the crane must remain stable and not topple over when the load is lifted and moved to another location.<br />
Lifting capacity<br />
Cranes illustrate the use of one or more simple machines to create mechanical advantage.<br />
<strong>THE LEVER. </strong>A balance crane contains a horizontal beam (the lever) pivoted about a point called the fulcrum. The principle of the lever allows a heavy load attached to the shorter end of the beam to be lifted by a smaller force applied in the opposite direction to the longer end of the beam. The ratio of the load's weight to the applied force is equal to the ratio of the lengths of the longer arm and the shorter arm, and is called the mechanical advantage.</p>
<p><strong>THE PULLEY.</strong> A jib crane contains a tilted strut (the jib) that supports a fixed pulley block. Cables are wrapped multiple times round the fixed block and round another block attached to the load. When the free end of the cable is pulled by hand or by a winding machine, the pulley system delivers a force to the load that is equal to the applied force multiplied by the number of lengths of cable passing between the two blocks. This number is the mechanical advantage.</p>
<p><strong>THE HYDRAULIC CYLINDER</strong>. This can be used directly to lift the load (as with a HIAB), or indirectly to move the jib or beam that carries another lifting device.<br />
Cranes, like all machines, obey the principle of conservation of energy. This means that the energy delivered to the load cannot exceed the energy put into the machine. For example, if a pulley system multiplies the applied force by ten, then the load moves only one tenth as far as the applied force. Since energy is proportional to force multiplied by distance, the output energy is kept roughly equal to the input energy (in practice slightly less, because some energy is lost to friction and other inefficiencies).<br />
<strong>&#124;&#124;Stability of crane&#124;&#124;</strong><br />
In order for a crane to be stable, the sum of all moments about any point such as the base of the crane must equate to zero. In practice, the magnitude of load that is permitted to be lifted (called the "rated load" in the US) is some value less than the load that will cause the crane to tip. Under US standards for mobile cranes, the stability-limited rated load for a crawler crane is 75% of the tipping load. The stability-limited rated load for a mobile crane supported on outriggers is 85% of the tipping load.</p>
<p>----------------------------------&#124;&#124;Types Of Cranes&#124;&#124;-------------------------------<br />
&#124;&#124;Railroad cranes&#124;&#124;<br />
A railroad crane is a crane with flanged wheels, used by railroads. The simplest form is just a crane mounted on a railroad car or on a flatcar. More capable devices are purpose-built.<br />
Different types of crane are used for maintenances work, recovery operations and freight loading in goods yards.<br />
&#124;&#124;Mobile crane&#124;&#124;<br />
The most basic type of mobile crane consists of a steel truss or telescopic boom mounted on a mobile platform, which may be rail, wheeled (including "truck" carriers) or caterpillar tracks. The boom is hinged at the bottom, and can be raised and lowered by cables or by hydraulic cylinders. A hook is suspended from the top of the boom by wire rope and sheaves. The wire ropes are operated by whatever prime movers the designers have available, operating through a variety of transmissions. Steam engines, electric motors and internal combustion engines (IC) have all been used. Older cranes' transmissions tended to be clutches. This was later modified when using IC engines to match the steam engines "max torque at zero speed" characteristic by the addition of a hydrokinetic element culminating in controlled torque converters. The operational advantages of this arrangement can now be achieved by electronic control of hydrostatic drives, which for size and other considerations is becoming standard. Some examples of this type of crane can be converted to a demolition crane by adding a demolition ball, or to an earthmover by adding a clamshell bucket or a dragline and scoop, although design details can limit their effectiveness.To increase the horizontal reach of the hoist, the boom may be extended by adding a jib to the top. The jib can be fixed or, in more complex cranes, luffing (that is, able to be raised and lowered).</p>
<p>A telescopic crane dismantling a 40 m tower crane in Cambridge, UK<br />
&#124;&#124;Telescopic crane&#124;&#124;<br />
A telescopic crane has a boom that consists of a number of tubes fitted one inside the other. A hydraulic or other powered mechanism extends or retracts the tubes to increase or decrease the total length of the boom. These types of booms are often used for short term construction projects, rescue jobs, lifting boats in and out of the water, etc. The relative compactness of telescopic booms makes them adaptable for many mobile applications.</p>
<ul>
&#124;&#124;Tower crane&#124;&#124;</ul>
<p>The tower crane is a modern form of balance crane. Fixed to the ground (or "jacked up" and supported by the structure as the structure is being built), tower cranes often give the best combination of height and lifting capacity and are used in the construction of tall buildings. To save space and to provide stability the vertical part of the crane is often braced onto the completed structure which is normally the concrete lift shaft in the center of the building. A horizontal boom is balanced asymmetrically across the top of the tower. Its short arm carries a counterweight of concrete blocks, and its long arm carries the lifting gear. The crane operator either sits in a cabin at the top of the tower or controls the crane by radio remote control from the ground, usually standing near the load. In the first case the operator's cabin is located at the top of the tower just below the horizontal boom. The boom is mounted on a slewing bearing and is rotated by means of a slewing motor. The lifting hook is operated by a system of sheaves.<br />
A tower crane is usually assembled by a telescopic crane of smaller lifting capacity but greater height and in the case of tower cranes that have risen while constructing very tall skyscrapers, a smaller crane (or derrick) will sometimes be lifted to the roof of the completed tower to dismantle the tower crane afterwards. A self-assembling tower crane lifts itself off the ground using jacks, allowing the next section of the tower to be inserted at ground level.</p>
<ul>
&#124;&#124;Hammerhead crane&#124;&#124;</ul>
<p>The hammerhead, or giant cantilever, crane is a fixed-jib crane consisting of a steel-braced tower on which revolves a large, horizontal, double cantilever; the forward part of this cantilever or jib carries the lifting trolley, the jib is extended backwards in order to form a support for the machinery and counter-balancing weight. In addition to the motions of lifting and revolving, there is provided a so-called "racking " motion, by which the lifting trolley, with the load suspended, can be moved in and out along the jib without altering the level of the load. Such horizontal movement of the load is a marked feature of later crane design. Hammerhead cranes are generally constructed in large sizes, up to 350 tons.<br />
The design evolved first in Germany around the turn of the 19th century and was adopted for use in British shipyards to support the battleship construction program from 1904-1914. The ability of the hammerhead crane to lift heavy weights was useful for installing large pieces of battleships such as armour plate and gun barrels. Hammerhead cranes were also installed in naval shipyards in Japan and in the USA. The British Government also installed a hammerhead crane at the Singapore Naval Base (1938) and later a copy of the crane was installed at Garden Island Naval Dockyard in Sydney (1951). These cranes provided repair support for the battle fleet operating far from Great Britain.<br />
The principal engineering firm for hammerhead cranes in the British empire was Sir William Arrol &#38; Co Ltd</p>
<ul>
&#124;&#124;Truck-mounted cranes&#124;&#124;</ul>
<p>A crane mounted on a truck carrier provides the mobility for this type of crane.<br />
Generally, these cranes are designed to be able to travel on streets and highways, eliminating the need for special equipment to transport a crane to the jobsite. When working on the jobsite, outriggers are extended horizontally from the chassis then down vertically to level and stabilize the crane while stationary and hoisting. Many truck cranes possess limited slow-travelling capability (just a few miles per hour) while suspending a load. Great care must be taken not to swing the load sideways from the direction of travel, as most of the anti-tipping stability then lies in the strength and stiffness of the chassis suspension. Most cranes of this type also have moving counterweights for stabilization beyond that of the outriggers. Loads suspended directly over the rear remain more stable, as most of the weight of the truck crane itself then acts as a counterweight to the load. Factory-calculated charts (or electronic safeguards) are used by the crane operator to determine the maximum safe loads for stationary (outriggered) work as well as (on-rubber) loads and travelling speeds.<br />
Truck cranes range in size from about 14.5 US Tons to about 120 US tons.</p>
<ul>
&#124;&#124;Rough terrain crane&#124;&#124;</ul>
<p>A crane mounted on an undercarriage with four rubber tires that is designed for pick-and-carry operations and for off-road and "rough terrain" applications. Outriggers that extend horizontally and vertically are used to level and stabilize the crane for hoisting. These telescopic cranes are single-engine machines where the same engine is used for powering the undercarriage as is used for powering the crane, similar to a crawler crane. However, in a rough terrain crane, the engine is usually mounted in the undercarriage rather than in the upper, like the crawler crane. HAC Cranes is one of the top leading dealers in the nation.</p>
<ul>
&#124;&#124;Crawler crane&#124;&#124;</ul>
<p>A crawler is a crane mounted on an undercarriage with a set of tracks that provide for the stability and mobility of the crane. Crawler cranes have both advantages and disadvantages depending on their intended use. The main advantage of a crawler is that they can move on site and perform lifts with very little set-up, as the crane is stable on its tracks with no outriggers. In addition, a crawler crane is capable of traveling with a load. The main disadvantage of a crawler crane is that they are very heavy, and cannot easily be moved from one job site to the next without significant expense. Typically, a large crawler must be disassembled and moved by trucks, rail cars or ships to be transported to its next location.</p>
<ul>
&#124;&#124;Gantry crane&#124;&#124;</ul>
<p>Portainer gantry cranes at the Hamburg Harbour<br />
A gantry crane has a hoist in a trolley which runs horizontally along gantry rails, usually fitted underneath a beam spanning between uprights which themselves have wheels so that the whole crane can move at right angles to the direction of the gantry rails. These cranes come in all sizes, and some can move very heavy loads, particularly the extremely large examples used in shipyards or industrial installations . A special version is the container crane (or "Portainer" crane, named after the first manufacturer), designed for loading and unloading ship-borne containers at a port.<br />
<strong>
<ul>
&#124;&#124;Overhead crane&#124;&#124;</ul>
<p></strong></p>
<p>Also known as a "suspended crane", this type of crane works in the same way as a gantry crane but without uprights. The hoist is on a trolley which moves in one direction along one or two beams, which move at right angles to that direction along elevated tracks, often mounted along the side walls of an assembly area in a factory. Some of them can lift very heavy loads.</p>
<ul>
&#124;&#124;Floating crane&#124;&#124;</ul>
<p>Floating cranes are used mainly in bridge building and port construction, but they are also used for occasional loading and unloading of especially heavy or awkward loads on and off ships. Some floating cranes are mounted on a pontoon, others are specialized crane barges with a lifting capacity exceeding 10,000 tons and have been used to transport entire bridge sections. Floating cranes have also been used to salvage sunken ships.<br />
Crane vessels are often used in offshore construction. The largest revolving cranes can be found on SSCV Thialf, which has two cranes with a capacity of 7,100 metric tons each.</p>
<ul>
&#124;&#124;Vessel (Deck) crane&#124;&#124;</ul>
<p>Located on the ships and used for cargo operations which allows to reduce costs by avoiding usage of the shore cranes. Also vital in small seaports where no shore cranes available. Mostly are electric, hydraulic, electro-hydraulic driven.<br />
&#124;
<ul>
&#124;Aerial crane&#124;&#124;</ul>
<p>Aerial cranes usually extend from helicopters to lift large loads. Helicopters are able to travel to and lift in areas that are more difficult to reach by a conventional crane. Aerial helicopter cranes are most commonly used to lift units/loads onto shopping centers, multi-story buildings, highrises, etc. However, they can lift basically anything within their lifting capacity, (i.e. cars, boats, swimming pools, etc.). They also work as disaster relief after natural disasters for clean-up, and during wild-fires they are able to carry huge buckets of water over fires to put them out.<br />
Examples include:<br />
Sikorsky S-64 Skycrane/Erickson Air Crane - civilian version<br />
CH-54 Tarhe - military version<br />
Mi-26 - Russian flying crane helicopter</p>
<ul>
&#124;&#124;Jib crane&#124;&#124;</ul>
<p>A Jib crane is a type of crane where a horizontal member (jib or boom), supporting a moveable hoist, is fixed to a wall or to a floor-mounted pillar. Jib cranes are used in industrial premises and on military vehicles</p>
<p>The jib may swing through an arc, to give additional lateral movement, or be fixed. Similar cranes, often known simply as hoists, were fitted on the top floor of warehouse buildings to enable goods to be lifted to all floors.</p>
<p>&#124;&#124;Crane-like machines&#124;&#124;<br />
The generally-accepted definition of a crane is a machine for lifting and moving heavy objects by means of ropes or cables suspended from a movable arm. As such, a lifting machine that does not use cables, or else provides only vertical and not horizontal movement, cannot strictly be called a 'crane'.<br />
Types of crane-like lifting machine include:<br />
Block and tackle<br />
Capstan (nautical)<br />
Hoist (device)<br />
Winch<br />
Windlass<br />
More technically-advanced types of such lifting machines are often known as 'cranes', regardless of the official definition of the term. Some notable examples follow:</p>
<ul>
&#124;&#124;Loader crane&#124;&#124;</ul>
<p>A loader crane offloading aerated concrete bricks at a building site<br />
A loader crane (also called a knuckle-boom crane) is a hydraulically-powered articulated arm fitted to a truck or trailer, and is used for loading/unloading the vehicle. The numerous jointed sections can be folded into a small space when the crane is not in use. One or more of the sections may be telescopic. Often the crane will have a degree of automation and be able to unload or stow itself without an operator's instruction.Unlike most cranes, the operator must move around the vehicle to be able to view his load; hence modern cranes may be fitted with a portable cabled or radio-linked control system to supplement the crane-mounted hydraulic control levers.<br />
In the UK, this type of crane is almost invariably known colloquially as a "Hiab", partly because this manufacturer invented the loader crane and was first into the UK market, and partly because the distinctive name was displayed prominently on the boom arm.</p>
<ul>
&#124;&#124;Rolloader crane&#124;&#124;</ul>
<p>This is a loader crane mounted on a chassis with wheels. This chassis can ride on the trailer. Because the crane can move on the trailer, it can be a light crane, so the trailer is allowed to transport more goods. Manufacturer of rolloader cranes include the Dutch Kennis and the Finnish company Hiab (Hydrauliska Industry AB).</p>
<ul>
&#124;&#124;Stacker crane&#124;&#124;</ul>
<p>A crane with a forklift type mechanism used in automated (computer controlled) warehouses (known as an automated storage and retrieval system (AS/RS)). The crane moves on a track in an aisle of the warehouse. The fork can be raised or lowered to any of the levels of a storage rack and can be extended into the rack to store and retrieve product. The product can in some cases be as large as an automobile. Stacker cranes are often used in the large freezer warehouses of frozen food manufacturers.<br />
<strong>----------------------&#124;&#124;OVER VIEW OF EOT CRANES&#124;&#124;-------------------</strong></p>
<p>An overhead crane typically consists of three important parts:<br />
The hoist providing up/down motion of the load item.<br />
The trolley, providing left/right for the hoist and the load.<br />
The bridge providing the back/forward motion of the hoist, trolley and the load.<br />
A EOT crane is permanently installed in a factory, shop or ware house to move the items which cannot be moved by human beings.</p>
<ul>
&#124;&#124;Use of overhead cranes&#124;&#124;</ul>
<p>Single grinder cranes find applications in Steel plants, Induction Furnaces, Paper mills, Cold Rolling mills, Arc Furnace, Pipe mills, Power plants, Hydro Power plant, Heavy Engineering industries, Container Handling, Dyeing Plants/Woolen mills, Chemical &#38; Pharmaceutical units, Petrochemical industry.<br />
Double girder cranes find application in Induction Furnace, Arc Furnace,Cold Rolling Mills, Paper Mills, Pipe Mills and Heavy Engineering Industry.</p>
<p>-<strong>----------------------------------------&#124;&#124;HOISTS&#124;&#124;---------------------------------------</strong><br />
Hoists are powered lifting assistants. They can be used to lift a heavy item or even a person. Hoists are usually placed overhead and attached to the ceiling, and may have a power supply. They use a suspension system, sling, and power supply cable. There are many different types of hoist, and it is important to be aware of how they  function before you begin using them.</p>
<p>There are two main types of powered hoist. Portable battery operated hoists have advantages and disadvantages. These are lightweight, and can be easily detached and moved to enable work on different tracks. However, if you are using them in different places, you still need the tracks in place to enable them to work at all the places you require. These are particularly popular in nursing homes for moving elderly people who may need assistance.<br />
A permanently attached ceiling track hoist is fixed to a ceiling track in one place. It has a powered lifting mechanism that you can operate continually. These are used in large warehouses or any place where lifting is performed routinely. Unlike the portable hoist, this type of hoist cannot be moved and hence does not require constant dismantling.<br />
The main power supply for these hoists comes through the main electricity supply. However, if the hoist fails to operate, there is sometimes the option of a backup battery supply. If the hoist does not have this option, then you should be able to operate it manually to lower the heavy item. Another factor to consider is the type of tracks and suspension for your hoist. You can choose from a straight or angled track. These basically hoist things in the direction they are set. With angled track hoists, you can move things around corners and bends. There are also turntable hoists that can swivel weights completely around.<br />
An x-Y tracking hoist uses two parallel tracks on each side of the room, either on the ceiling or opposite walls. Hoists of this type can move the weight anywhere in the room as needed. Gantry and free standing hoists have floor-standing frames. They are particularly useful for people who do not have much space to maneuver and are sometimes used when moving elderly people in and out of bed.<br />
Different hoists have different lifting capabilities. Hoists with a powered lifting mechanism take all the strain of the item and place none on the person operating it. Also remember to check that a hoist has the lifting capacity you require to move your items. The lifting height range will also vary between hoists; each has its own maximum height and can usually not be extended.<br />
The hoist's safety aspects are another important factor. Does it have an automatic cut off switch? This will enable quick power cut off if there is an emergency. Is there a battery back-up supply or wind down option, in case of power failure? All of these factors should be checked be before buying or operating a hoist.</p>
<p>-----------------&#124;&#124;SOME RELATED TERMS WITH CRANES&#124;&#124;-----------------<br />
<strong>HOIST:</strong> A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium. The load is attached to the hoist by means of a lifting hook.</p>
<p><strong>SIMPLE MACHINE</strong>: In physics, a simple machine is any device that only requires the application of a single force to work. Work is done when a force is applied and results in movement over a set distance. The work done is the product of the force and the distance. The amount of work required to achieve a set objective is constant; however the force required can be reduced provided the lesser force is applied over a longer distance. The ratio between the two forces is the mechanical advantage.</p>
<p><strong>MECHANICAL ADVANTAGES</strong>: In physics and engineering, mechanical advantage (MA) is the factor by which a mechanism multiplies the force put into it.The ratio A:B is called mechanical advantage.</p>
<p><strong>HYDRAULICS</strong>: Hydraulics is a topic of science and engineering dealing with the mechanical properties of liquids. Hydraulics is part of the more general discipline of fluid power. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. Hydraulic topics range through most science and engineering disciplines, and cover concepts such as pipe flow, dam design, fluid control circuitry, pumps, turbines, hydropower, computational fluid dynamics, flow measurement, river channel behavior and erosion.</p>
<p><strong>LIFTING HOOK:</strong> A lifting hook is a device for grabbing and lifting loads by means of a device such as a hoist or crane. Lifting hooks are usually equipped with a safety latch to prevent the disengagement of the lifting wire rope sling, chain or rope to which the load is attached. Hook may have one or more built - in pulleys to amplify the lifting force.</p>
<p><strong>WIRE ROPE</strong>: Wire rope consists of several strands laid (or 'twisted') together like a helix. Each strand is likewise made of metal wires laid together like a helix. Initially wrought iron wires were used, but today steel is the main material used for wire ropes.</p>
<p><strong>&#124;&#124;Design &#38; Constructional Features of  “LIFT UP” Electric Wire Rope Hoists&#124;&#124;</strong><br />
<strong>DESIGN</strong>: Hoists are designed as per standards (IS 3938 Class II) duty operations and repetitive use under most severe operating conditions. Hoists specially designed for higher lifts, faster hoisting &#38; cross travel speeds &#38; moveable on curved.</p>
<p><strong>MOTORS:</strong> Hoist &#38; crane duty hour rated squirrel cage induction motors, confirming to IS 325 with comparatively higher H.P. and higher starting torque to reduce handling time. It is flange mounted to suit the design and provided with suitable insulation</p>
<p><strong>ROPE DRUM:</strong> The rope drum should be made of seamless pipe machined &#38; grooved accurately, to ensure proper seating of wire rope in a proper layer. The drum should be fitted with two heavy duty Ball / Roller bearings of reputed make for smooth operation &#38; longer life.<br />
<strong>ROPE GUIDE</strong>: The rope guide should be made of special close grain castings &#38; is specially designed and accurately machined to suit the grooves of the rope drum &#38; prevents the rope from overriding &#38; loosening. It also operates the limit switches provided as a safety feature to limit the over hoisting &#38; over lowering of the hook. The guide is so designed to ensure proper tensioning of the rope.<br />
<strong>GEAR BOx:</strong> Totally enclosed oil splash lubricated &#38; dust free gear box should be provided for smooth, trouble free &#38; longer life. All gears are helical type and cut from alloy steel / low carbon steel on hobbing machines for achieving higher precision &#38; a special process of gear toughening ensures smooth, silent, trouble free running of drive system. The pinions and gears are supported on anti-friction bearings on both ends.<br />
<strong>MODULAR</strong> : The design is of modular construction and its maintenance is easy as each component<br />
<strong>CONSTRUCTION: </strong>brake, motors, gear box &#38; Control panel are independent units and are accessible easily. The complete hoist can be easily maintained by keeping it in its installed position, thus saving on precious labour as well as down time maintenance time.<br />
<strong>BEARINGS</strong>: Heavy duty deep groove ball / roller bearings of reputed make i.e. FAG / NACHI or equivalent make are used on all rotating parts and are grease packed for longer bearing life.<br />
<strong>TROLLEY: </strong> Push-pull, Hand Geared or Motorized Trolleys are of adjustable type and fitted with ball bearings to suit recommended size of I-Beams.<br />
<strong>HOOKS: </strong> Heavy duty high tensile steel forged hooks are used &#38; fitted in such a manner that they rotate and swivel freely.<br />
<strong>BRAKES:</strong>  Heavy duty 3 phase AC fail safe electromagnetic disc type brakes are provided on hoisting motion held closely to sustain the full load when current supply is switched off either accidentally or intentionally. It is mounted on the rear end of the motor for easy maintenance.<br />
<strong>TESTING</strong>: The hoist components should be subjected to strict quality control procedures. And the hoist should be finally tested to 25% overload to prevent any accidents</p>
<p><strong>-----------------&#124;&#124;SIMPLER HOIST DESIGN REDUCES COSTS&#124;&#124;-----------------</strong><br />
In brief, the hoist has a drive that is formed with an integral decelerator and brake flanged on one side of the main frame. The drive decelerator and brake are formed as a single body and the traveler can be detached from its mounting simply. This is said to make installation and exchange easy, reducing maintenance costs. This is operated together with the wire-rope drum by a drive motor mounted on the opposite side of the flange.<br />
A traveler unit connected below the main frame has wheels coupled to bearings on both sides of the unit through a bored space. Each wheel has an involutes spine gear groove on its centre bore matching a groove gear on the drive shaft. This design reduces the weight and volume of the main frame compared to previous designs, thereby making production costs lower. Other claims include reduced transports costs and simpler installation.<br />
Existing art problems<br />
According to the earlier laws, one type of conventional electric hoist has an intermediate shaft, connected to the traction motor, and extending through the inside of the wire-rope drum to a decelerator and electromagnetic brake. This makes it comparatively long, causing a loss in power. Any widening of the wire-rope drum also means that the intermediate shaft has to be lengthened, but the wire-rope drum cannot be increased over a predetermined width. The conventional design also means that the extended intermediate shaft rotates with the lifting operation of the hoist.<br />
It is claimed that a high speed in the intermediate shaft causes vibration, which can damage the object being lifted. Avoiding this problem by rotating the intermediate shaft at a predetermined speed limits the speed and capacity of the traction motor, and thus limits the weight of the object that can be conveyed by the hoist.<br />
An existing design of hoist, adapted to carry heavier objects, uses a motor rotating at high speed. In this a decelerator, hoisting traction motor and brake are mounted at one side of the drum with a horizontal arrangement on the upper portion of a main frame, also carrying the wire-rope drum. Four wheels on the corners of the frame each have a travelling decelerator, travelling motor and brake formed at one side of each to operate in cooperation. This arrangement of horizontal fixing means that each part occupies a relatively large space, resulting in a bulky structure. The large weight increases installation and production costs.<br />
The design employs a sheave to support the wire-rope drum at its centre and perpendicular to it. This gives an angular differential to the object being transported, necessitating a capacity of hoist traction motor greater than the weight of object being carried, again increasing production costs.<br />
The decelerator is housed in a gearbox with upper and lower portions containing lubricating oil. This may result in oil leakage through connections over a long period of time. In addition, the couplings of the decelerator, traction motor and wire-rope drum are force fittings that cause difficulties in assembly, disassembly, maintenance and repair.<br />
The travelling wheels, driven in cooperation with each other, are integral with the main frame of the hoist, causing higher conveyance costs and high installation costs for high-capacity hoists.<br />
An  Idea<br />
The invention tackles these problems with a winding sheave at the lower part of the winding drum connected to a driving sheave with a lifting hook to operate in parallel with each other. All the parts can be packaged separately for transport to the installation site, to make installation work easy and reduce transport costs. The travelling section is detachably mounted to the lower part of the main frame. Each of the parts can be exchanged in accordance with the load and size of the object, helping to standardize the product’s components, and improves power efficiency through connecting the parts in series.<br />
The previously mentioned spline gear couplings on each of the travelling wheels and drive shafts makes the assembly process easier and increases the rotational efficiency of the couplings between the gears.</p>
<p><strong>----------------------------&#124;&#124;LOAD HOIST ARRANGEMENT&#124;&#124;--------------------------</strong><br />
There are load hoist arrangements that enable a manually-guided load moving in three dimensions to be driven by sensing the lateral movement of a lifting cable. These designs often have a problem with self-induced vibrations or excessive swinging. The changes in acceleration and direction, induced manually by the operator to the load-carrying device often make it start to swing. Once it has started to swing, it is difficult to stop, especially if the load is heavy, decreasing the system's maneuverability and increasing the risk of accidents.<br />
A load hoist arrangement consists of a traversing device with traveling bridge and carriage. Two motors on the support structure drive cables that pull the traveling bridge in either direction.<br />
But the design has some drawbacks. There is a need for a load hoist arrangement that supports motions in both lateral directions and not only along a line. By positioning the motors on the support structure, the design makes a relatively stable working environment. However, there are a lot of cables connecting static components with moving parts. These cables often connect to sensitive connections and couplings that will be prone to wear in this dynamic environment, risking less accurate motion control and increasing the need for maintenance. There is also a need for a load hoist arrangement that is easy and quick to install.<br />
The invention is designed to overcome these issues and be capable of handling manually-induced accelerations, maintaining stability in the load hoist arrangement even when handling heavy goods.<br />
A control device is arranged along a lifting cable between a traverse device and load-carrying device. This load-carrying device is manually guidable in a three-dimensional space. A driving device controls the lateral movement of the load carrying device.<br />
The vertical motion is not part of this patent. An industry-standard electronically-controlled balancer controls the vertical motion of the load-carrying device. A transmitter in the control device that tells the hoist to compensate for any load, so that an operator guiding the crane manually will experience a fraction of the total resistance of the load.<br />
The driving device comprises two motors secured to carriage. The ends of two drag cables and are secured to opposite ends of the supporting rails and cross at traveling bridge. The drag cables cross each other at the carriage so that a driving wheel unit of one motor works in contact with one drags element<br />
The axle unit has two separate grooves, one for each drag cable. The combination of the two drag cable paths, each working in a different direction, locks the axle unit, providing the driving device with increased stability. The drag elements are arranged to turn in a 90 degree angle around a pulley from their anchor point to the carriage. With this arrangement, possible imperfections will be almost automatically corrected because the two drag cables working in opposition to each other.<br />
The friction between the drag element and possible guide wheels axle units  and driving wheel units together with the drag cable path will prevent the drag cable from sliding when the driving device is in operation.<br />
The carriage is moved by actuation of the two motors and hence the load carrying device will follow. The motors are capable of clockwise and counter-clockwise motion.<br />
The motors are actuated by the movement of the load. The angle of a load-carrying element is used as reference of force impact for guiding and controlling the driving device, and thus the load carrying device in a lateral direction. The traverse device moves in proportion to the force manually applied by the operator. This allows a controlled movement of the load carrying device relieving the operator from bearing the actual weight of the load while still being able to lift and move them.<br />
The invented driving device is easy to manufacture and install since the carriage can be made in a standardized manner and the support structure together with the drag elements are simple to adapt to suit the location in question. Furthermore, the need for control data transmission cables is limited to a zone near the carriage. This design reduces the need for cable racks interconnecting motors and sensors.<br />
Since it is a dynamic system, often covering a large working area, and frequently used, the risk for play in the interconnections of the control system, e.g. motors, transmitters and recording sensors,may lead to downtime and reduced productivity<br />
We  are concerned with the design of the hoisting arrangement of 2 tonne capacity of EOT crane ,which will lift the load up to a distance of 8 meters.</p>
<p><strong>1.DESIGN OF HOOK</strong></p>
<p>Selection of section                        :    The section is trapezoidal<br />
Selection of material                       :    Mild steel<br />
Load to lift                                    :    2 tonne<br />
Considering 50 % over loading.<br />
So the design load                           = 2 tonne+50% of 2 tonne      = 3tonne<br />
Taking the help of (IS 3815-1969) for selection of material for 8 dimensions of crane hook.In IS 3815-1969 the nearest selection for 3.3 tonne is 3.2 tonne.<br />
For load 3.2, proof load (P) is     6.4 tonne.<br />
So C    =        26.73√P        =      26.73 x √6.4<br />
                                          =      67.62<br />
                                          ≈     68 mm<br />
A     =        2.75 C               =     2.75 x 68           ≈ 187 mm<br />
B     =        1.31 C               =     1.31 x 68           ≈   89mm<br />
D     =        1.44 x C           =      1.44 x 68          ≈   98mm<br />
E      =       1.25C                =     1.25 x 68           ≈   85mm<br />
F      =        C                      =      68mm<br />
 G      =        35mm<br />
G1   =        M33, Pitch     =      6mm (Coarse series)<br />
H     =        0.93 x C        =      0.93 x 68          ≈     63mm<br />
J       =        0.75 x C        =      0.75 x 68          ≈     51mm<br />
K     =        0.92 x C         =     63mm<br />
L      =       0.7 x C           =      0.7 x 68            ≈     48mm<br />
M     =       0.6 x C           =      0.6 x 68            ≈      41mm<br />
N     =       1.2 x C            =      82mm<br />
P      =        0.5 x C           =      34mm               ≈      34mm<br />
R      =       0.5 x C           =      0.5 x 68            ≈<br />
U  = 0.33 x C = 0.3 x 68≈20 mm<br />
Checking for strength Area of the section = ½ x 63 x (41+8) = 1543.5 mm2<br />
Centroid from ‘a’<br />
=
<ul>
(.05 x 8 x 65) 63/3+(.5 x 41 x 63) x (2 x 63)/3</ul>
<p>                       ½ x 68 x (41+8)<br />
=     38.571mm<br />
=     38.6 mm= h2<br />
So centroid from b = 63-38.6=24.4mm =h1<br />
0                                             = 34 +24.4 = 58.4mm<br />
r0                           = A/(dA/u)<br />
dA/u                    = [b2+r2/h (b1-b2)] ln r2/r1 – (b1-b2)<br />
                            =28.65mm<br />
r0		         = A/(dA/u) =        1543.5	     =	53.87  53.9 mm.<br />
                                28.65<br />
e= 0-r0 = 58.4 - 53.9 = 4.5mm</p>
<p>Moment<br />
M   = -P x 0<br />
= -3 x 58.4<br />
= - 175.2 (tonne x mm)<br />
Stress due to bending is given by<br />
b 			   = M X 4<br />
                                   Ae r0-y<br />
For point a<br />
Y                           = -(e+h2)<br />
                             = -(4.5+38.6)<br />
                             = - 43.1 mm<br />
For point b<br />
Y      =  r0-r1<br />
= 53.9 – 3.4<br />
= 19.9 mm<br />
Stress due to direct loading             = P/A<br />
= 3/1543.5<br />
= 1.9436 x 10-3	Tonne/mm3<br />
Stress due to curvature of ‘a’<br />
ba	                       =            - (-175.2) x -43.1<br />
                             1543.5 x 4.5  {53.99 – (-43.1)}<br />
                        =           0.0112<br />
So total tress at a<br />
                          = - 0.0112 + 1.9436 x 10-3<br />
                      = - 9.2642 x 10-3 Tonne/mm2<br />
                      = - 9.2642 kg/mm2  -90.85 Mp<br />
Stress due to curvature at b<br />
bb		      =        -(-175.2) x . 19.99   .<br />
                              1543.5x 4.5	 (53.9 – 19.9)<br />
                         =     0.014763<br />
So total stress at b<br />
=bb + 1.9436 x10-3<br />
=0.014763 + 1.9436 x 10-3<br />
=0.0167 tonne/mm2<br />
= 16.7 Kg/mm2  163.84 MPa<br />
Let the material be class 4 carbon steel ( 55C 8)<br />
Ultimate tensil strength I 710MPa<br />
Design strength  = 	Ultimate tensil strength<br />
                                   Factor of safety<br />
                                 = 710/4<br />
 		                = 177.5 MPa<br />
163.84 &#62; 177.5<br />
So design is safe<br />
Determination of length of threaded portion<br />
Pitch  		= 6mm<br />
Nominal dia of thread = 33 mm (G1) = d<br />
Considering the screw and thread are of single safest &#38; square mean diameter of screw =<br />
dm                = d- (p/2)<br />
                    = 33 – (6/2)<br />
                    = 30<br />
tan  	   = 1/dm = 6/( x 30)<br />
tan           = tan-1	{ 6/( x 30)} = 3.640<br />
Let the co-efficient of fraction be 0.15<br />
So  	     = tan  = 0.15<br />
               = 8.530<br />
Torque required to resist the load<br />
T               = W x dm* tan ( + )<br />
                                 2<br />
Where w is the weight of load is 3 tonne and the load of the hook itself.<br />
The maximum weight of the hook is 50kg (from the use of the soft ware ‘Pro-Engineer’)<br />
So<br />
T                = 3050x 30 x tan (3.61+ 8.53)<br />
                                         2<br />
                   =9866.42 Kgmm<br />
Stress induced in the screw<br />
Direct tensible stress (allowable or design)<br />
                 =4w/ d02<br />
d0                = core diameter of the screw.<br />
dc                = d-p = 33-6 = 27 mm<br />
1                =  4x 3050<br />
                           272<br />
=	5.326 kg/mm2  52.24MR<br />
Torssional shear stress<br />
 		    =  16T	            	  =	16x9866.42<br />
                           de3			             x 273<br />
                       = 2.5529 Kg/mm2                   = 25MP</p>
<p>Maximum shear stress in the screw<br />
max                       = ½   (2 + 4 2)<br />
                    = ½ √ (52.242 + 4 x  252)<br />
                    = max = 36.15Mpa</p>
<p>Height of the nut<br />
a)Considering bearing action between the thread in engagement.<br />
Let ‘n’ is no of thread in engagement with screw.<br />
Considering bearing action between nut &#38; screw.<br />
Let the permissible bearing pressure =pi= 6 MR.<br />
We know<br />
Pi                                               = 	   4W<br />
                                      (d2-dc2) x n<br />
So      6	           = 	4x3050 x 9.8<br />
                                     (332-272) x n</p>
<p>N	                     =	4 x 3050 x 9.8<br />
                                     (332-272) x 6<br />
                                     1.27 x 9.8<br />
                                     12.5<br />
So the height of the nut is = 2 x 12.5 = 25mm.<br />
b) Considering shear failure of thread across root<br />
Shear stress induced<br />
	                   =    	.	W	.<br />
                                     dc(0.5xP) xn</p>
<p>                             =	.	3050 x 9.8	.<br />
                                        x 27 x (0.5 x 6) x n</p>
<p>                             =	117.46<br />
                                           n<br />
                             =	0.5 x 177.5	=	117.46<br />
                                            n                          n<br />
                             =	   117.46<br />
                                       177.5 x0.5<br />
                             =	     1.32      =	     2<br />
So height is  n x p = 2 x 6  =12mm<br />
Tacking the highest value 25mm<br />
Design of pin which will carry the dead load &#38; the load of hook.<br />
We have to determine the dimension of ‘t’.<br />
n 		     =                M  x Y<br />
                                              I<br />
                        = 	            M   x (24)<br />
                                         I          2<br />
Where “I” is moment of inertial about         bh3 t x 243 x  2<br />
                                                                             12	         12<br />
Maximum bending moment for = M = ¼ x W x L<br />
Let  L 	= 70 mm<br />
So M = ¼ x 3050 x 70	            =	2 x 26687.5 Kgmm.<br />
                                                   =	  2 x 261.715 x 103 N-mm<br />
                                                 =  2x 261.715 x 103    x   24<br />
                                                           1 t x 243	                     2<br />
             177.5      = 	 1363 x 2<br />
                                      t<br />
t 		 = 1363 x 2 	=	7.8 x 2  15.2 MM<br />
                         177.5<br />
                      	16 mm<br />
Taking 20 m for additional safety<br />
Diameter of the projected portion<br />
The projected position is undergo only shearing failure.<br />
Design shear stress  = 0.5 x design tensive stress.<br />
Force action on each side i.e. projected portion is<br />
3050/2     =1525 kg  14.95 x 103<br />
 15 KN<br />
So the minimum value of the height of the projected portion is 15mm, taking n= 40mm for screwing arrangement.<br />
  		                                   =	       15 x 103<br />
                                                                  /4 x dk2<br />
                                                       =       177.5 x 0.5  = 15 x 103<br />
                                                                 (/4) dk2<br />
                                                       =  dk2  = 15 x 103 x 4<br />
                                                                177.5 x 0.5 x <br />
                                                       = dk2 =  15 x 103 x 4<br />
                                                                177.5 x 0.5 x <br />
                                                       =	        215.19<br />
                                                       =         14.66<br />
                                                                 15mm<br />
Taking 20 mm for additional safety purpose.<br />
So that it can be turned to thread in size ‘m20’.<br />
Height of the projected portion<br />
P * x * dk = w/2<br />
Where p = bearing pressure or crushing stress.<br />
Let p	 = 210 MPx<br />
Allow crushing stress =210/4 =<br />
210/4 x x x 20 = 3050 x 9.8<br />
                              2<br />
x                  =  3050 x 9.8 x 5<br />
                          2 x 20 x 210<br />
                     = 3.56 mm x 4<br />
                     = 14.024 =15 mm<br />
So the minimum value of the height of the projected portion is 15 mm, taking x = 40 mm for<br />
 screwing arrangement.</p>
<p>Design of link and the cover plate<br />
Thickness of link and cover plate should not be minimum.<br />
Let the material be (55C8).<br />
a)Hole fopr placing the pin which will carry the hook will be ‘dk’ i.e. 20 mm.<br />
zchecking for the failure of link &#38; cover plate combindely(as they are of same material and undergone same condition of failure).<br />
Mode of failure<br />
Tearing of cover plate &#38; link at the edge.<br />
Crushing of cover plate and link.<br />
Breaking at the lowest cross section.<br />
i).Considering tearing of cover plate &#38; link at the edge</p>
<p>Experiments from the riveted joints have shown that if the distance between the centre of rivet<br />
and the edge is 1.5 times the diameter of the rivet.The element will not undergo the failure of tearing at the edge.<br />
The same condition is also applicable in our case.<br />
But for more safety reasons taking the distance between the centre of the projected element and the edge of the cover plate &#38; linkis 2 times the dia of the projected element.<br />
So   Z = 2 x dk<br />
= 2 x 20 = 40 mm<br />
Considering tensile failure at the lower cross section<br />
So σd = w/2<br />
A<br />
177.5 = 3050 x 9.8/2<br />
             2 x x x 30</p>
<p>x = 3050 x 9.8/2<br />
     2 x 30 x 177.5</p>
<p>=   28/2 mm ≈ 1.4 mm</p>
<p>Considering crushing failure<br />
Force = σcrushing(d)  x projected area<br />
3050 x 9.8 = σcrushing(d) x (20 x x)<br />
                       FOS<br />
     = 3050 x 9.8 x 4 = 14.24 mm ≈ 15 mm<br />
            2 x 210 x 20<br />
So taking maximum of x i.e 15 mm, So  x = 15 mm</p>
<p>AutoCAD drawing Of Cover plate</p>
<p>AutoCAD Drawing Of Link</p>
<p>Design of shaft carrying the pulley<br />
The weight of each cover plate is 2.5 kg.<br />
Weights of each link weigh 2 kg.<br />
So weight of 2 covers plate &#38; 2 link<br />
Is 2 x 2.5 + 2 x 2 = 9 kg.<br />
So the total weight which the shafts carry is 3050 + 9 = 3059 ≈ 3060<br />
Each Side subjected to a load of 3060/2 = 1530 kg.<br />
The shaft is only subjected to<br />
Crushing failure (at the cover plate and link).<br />
Shear failure.<br />
Crushing failure (at the pulley)<br />
Considering shear failure<br />
 = f/a<br />
				 = allowable shear stress<br />
                                        =  0.5 x 177.5       =   0 .5 x 177.5    = 22.2 MR<br />
                                               FOS	                      4<br />
Stress induced   = 1530 x 9.8     =   150042<br />
                               π/4 x 302	   π/4 x 302<br />
                          =  21.22 MPa<br />
As induced stress is less than that allowable stress, the design is gate.</p>
<p>Considering crushing failure at the cover pole<br />
Crushing stress 		= Force/Protected area<br />
Allowable stress 		= 240/4     =  60MPa</p>
<p>Induced Crushing stress    	=          Force<br />
Projected area<br />
                                                =    3060 x 9.8<br />
                                                        70 x 40<br />
As allowable induced stress  60.86 KN. The selection is feasible.</p>
<p>Design of Sheave      </p>
<p>a	       =        40mm<br />
b              =         30mm<br />
c               =	      7mm<br />
d               =         18mm<br />
e               =          1mm<br />
l                 =         10mm<br />
r                 =        12mm<br />
r4                        =          8mm<br />
h                  =      25mm<br />
r1                 =        4mm<br />
r2                =         3mm<br />
r3                      =         12mm<br />
Material is caste iron<br />
Let dia of the sheave  =  20 x d<br />
=  20 x 14<br />
=  240mm<br />
The reference is made from Rudenko,N.’Materials Handling Equipment ‘,Mir Publishers, Moscow(1969).<br />
P .86,Table 16.</p>
<p>Drum design<br />
Drum grove size<br />
Referring to Redenko,N “Materials Handing Equipment”,Mir publishers,Moscow (1969),P.No.90 table 17.<br />
Considering standard groove of drum, for, diameter of wire 15 mm as it is nearest to 14mm.<br />
Drum diameter = sheeve diameter = 240 mm.<br />
r 1   =  0.53 x d (d ≈15)   =   9mm<br />
s1      =   1.15d  =  17mm<br />
C1      =   0.25  d =   5mm<br />
No. of turn on each side of drum<br />
Z  =  (hi/πd) + 2 =<br />
Where<br />
H   = Lifting Height.<br />
I     = Ratio of the pulley system.<br />
D    = Drum diameter ≈ 45 x 14 = 630<br />
So   Z  = ( 8.00 x 2) + 2<br />
                   Π x63<br />
Z = 10<br />
Full lenth of drum for one rope.<br />
L = (2HI + 7)Si       (I = 2 assumed)<br />
              πD<br />
    =(2 x 800 x 2 + 7)1.5<br />
    =34.75<br />
    ≈35 cm<br />
The drum is made up of IS grade       = SG 80/2<br />
With stress = 480Mpa<br />
W = 0.02 x 630 = 10<br />
 = 22.6<br />
≈ 23 mm<br />
Outside dia of the drum Do  = D + 6d<br />
				= 630 + 6 x 14 = 714mm<br />
Inside dia of the drum          = Di = D – 2W<br />
				= 630 – 2 x 25<br />
				= 584 mm<br />
Checking of strength<br />
Bending Stress in drum<br />
σbend   =       8WLD<br />
               π(D4 – Di4)<br />
         =    8 x 6200 x 9.8 x 35 x 630<br />
                   Π x (6304 - 5844)<br />
         =       0.0828MP</p>
<p>Maximun Torque<br />
Tmax   =     W (D + d)<br />
	        2<br />
        =   6200 x 9.8 (630 + 14)<br />
                         2<br />
= 19.564 x 106<br />
Maximum Shear Stress<br />
 =    16 Tmax D<br />
         π(D4 – Di4)<br />
    =  16 x 19.56 x 106 x 630<br />
          π x (6304 - 5844)<br />
   ≈ 1.523 MPx<br />
Direct Compressive Stress<br />
             =           W             = σc<br />
                         wSi<br />
             =      6200 x 9.8<br />
                       23 x 17<br />
           =      155.4MPx</p>
<p>Maximum Stress in the Drum<br />
σ    = √σbend2 + σc2 + 4max2<br />
 = (0.08282 +155.42 = 4 x 1.5232)1/2</p>
<p>σ &#60; 480 MPx, S the Design is safe.</p>
<p>Fastening Of Rope With The Drum<br />
For 14 mm dia<br />
Locating Dimension<br />
Pitch of screw = 53 mm<br />
T = 43 mm<br />
Screw size<br />
Lo   =    18 mm<br />
L     =     50 mm </p>
<p>Plate<br />
 C   =    7 mm<br />
No. of fastenings      =  1<br />
Selection of Motor<br />
W = 3100 kg x 9.8 m/s2<br />
V = 0.2m/sec<br />
So power required  = 3100 x 9.8 x 0.2<br />
  			  =  6080.123Nm/sec<br />
			  = 6.08 Kwatt<br />
Taking 11 Kwatt 3 phase induction motor (flange type) of 11 KW (nearest to 6.08KW)<br />
Frame No. 132 M<br />
Flange designation F265B<br />
The speed is 1000 RPM<br />
By using gear box the speed can be reduced to 300 RPM	 </p>
<p>GearBox Calculation<br />
Gearbox ratio = (Input RPM x π x rope drum dia)<br />
			    (speed x no. of falls /2)<br />
                      =  ( 980 x π x .714) = 183.54<br />
			(3.00 x 4 )</p>
<p>Brake calculation<br />
Required Brake Torque = 1.5 x 716.2 x mech H.P.<br />
					Motor RPM<br />
				 = 1.5 x 716.2 x 50.12<br />
					      300<br />
				 = 53.84 Nm<br />
Design of wormset<br />
Power    =   P   =  6.08 Kwatt<br />
RPM of Worm   =   Nw  =  V x 60<br />
				    πd<br />
                            =   0.2 x 60<br />
                                  π x 0.63<br />
RPM of Worm Gear NG = 300 RPM<br />
So   R   =  NG<br />
               Nw<br />
             = 300<br />
                  6<br />
Let Ф = 14.5o<br />
Let the centre distance = C = 300 mm =0.3m<br />
Pitch circle diameter of the worm<br />
Dw =   C.8750  =  3Pc<br />
          3.48<br />
Dw =    3.8750  =  0.10020m<br />
          3.48</p>
<p>     ≈ 100mm<br />
Dw = 3Pc = 3Pa = 3 x π x ma<br />
So ma = Dw/3π          =   100.2/3π<br />
          = 10.63 mm    ≈ 11mm    </p>
<p>Pitch circle dia of the gear Dg   =   2C - Dw =  2x 300 – 100   =  500 mm<br />
Velocity ratio  =  Ng/Nw       =      50<br />
                           Ng/Nw       =     Dg /(ma x Nw)<br />
                            50            =    Dg/(11 x Nw)<br />
                           Dg                   =       50 x 11 x Nw<br />
Nw	1	2	3	4<br />
Dg     mm	550	1100	1650	2200</p>
<p>Taking Ng  =  1 , because Dw  is closer to the calculated.<br />
So, Dg    =  550<br />
Dw   =   2C  -   Dg<br />
         =   2 x 300 -500<br />
 =   50mm<br />
Face width of the gear<br />
 b      =   0.73 x  Dw<br />
         =  0.73 x 50<br />
         =   36.5<br />
         =   40 mm<br />
Static strength of Bronze<br />
σd  = 90MPa<br />
In worm drive irrespective of materials of worm and worm ger,the gear is weak.<br />
So design should be based on gear.<br />
Tangential load on the gear :<br />
Ft  =  σ π mn y b<br />
     =   (σd x Cv)π mn y b<br />
Velocity factor Cv  =            6    .<br />
                                 6 + Vg<br />
Vg    =    π x Dg  x Ng<br />
                           60<br />
        =     8.69<br />
Cv        =     6         =   0.41<br />
            6 + 8.69<br />
 Form factor<br />
 Y   =   0.124 – 0.684<br />
                         Ng<br />
       =   0.11132<br />
Tan λ     =  m x Nw<br />
                   Dw</p>
<p>              =  11 x 1<br />
                    50<br />
λ     =    tan-1 (.22)     =    12.4o</p>
<p>Nominal Module     =     m (ma) x cos λ<br />
                                =    11 x cos 12.4<br />
                                =    10.743 mm<br />
Ft = 90 x .41 x π x 1o.743 x .11132 x 40<br />
    = 5545.47 N<br />
    = 5.55 KN<br />
Power Capacity      =    P1             =  Ft x Vg<br />
                               =   5.55 x 103 x 8.69<br />
                               =   48.19 K watt<br />
Which is greater than capacity so the design is safe.<br />
Powe capacity of drive from wear point of view</p>
<p>P2 = Dg x b x W x Vg<br />
    =  550 x 40 x W x 8.64<br />
W = .550  = Material combination factor.<br />
For worm and worm gear made up of hardened steel and phosphor bronze<br />
So, P2 =  (550 / 1000) x 40 x .55 x 8.64<br />
           =   104.4 Kwatt<br />
Power capacityof the drive, from the heat dissipation point of view is given by :<br />
P3      =     3650 x C17<br />
               R + 5<br />
       =    3650 x 300 17<br />
               50 + 5<br />
       =     361.99K watt<br />
So The safe power capacity is minimum i.e P1  = 48.19 Kw</p>
<p>CONCLUSION : The design of the hoist of EOT crane is done Numerically .We can implement the design practically in industries for various lifting jobs.</p>
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<title><![CDATA[Apple Unveils Mean Great go Mac OS Sealed book Wildcat]]></title>
<link>http://nilscorykda.wordpress.com/2008/07/26/apple-unveils-mean-great-go-mac-os-sealed-book-wildcat/</link>
<pubDate>Sat, 26 Jul 2008 12:39:35 +0000</pubDate>
<dc:creator>nilscorykda</dc:creator>
<guid>http://nilscorykda.wordpress.com/2008/07/26/apple-unveils-mean-great-go-mac-os-sealed-book-wildcat/</guid>
<description><![CDATA[Apple Unveils Sidle up to Extreme Mac OS The unknown OpalApple historically unveiled a approaching s]]></description>
<content:encoded><![CDATA[<p>Apple Unveils Sidle up to Extreme Mac OS The unknown Opal</br></br>Apple historically unveiled a approaching significant restatement in re Mac OS Sealed book Tiger, the seventh keynote dumping in respect to the world’s radical a la mode functional envisagement. </br>        Itemized so spar-decker mod October, Candy cane introduces over and above 300 up-to-the-minute bearing, attended by a newfashioned Desktop and Dump in association with Stacks, an meaningful being praxis on route to chart files; an updated Finder featuring Pretense Flow™ and a underived lust for learning up absolutely prey on and convey files between increase Macs; Breathless Leer, a unfledged presence so as to hell for leather picture show far out files precluding inlet an ill use; Cycle Fixture, a running maintien headed for indisputably and automatically take sides with and refurbish discomposed files ochry a ripe Mac®; Spaces, a plenary instant participate towards lead the way groups touching applications and superficially traffic between the authorities; and worse iChat and Airfreight applications, which deliberately express an opinion users until tell although pluralistic creatively.</br></br>“Patchwork quilt is the put let loose of on Mac OS N so as to party, a cut above squarely Jaguar, and say-so thither let out Mac OS X’s upper hand as an example the far out transfigured and innovative behavioral reference system favor the continent,” parol Steve Jobs, Apple’s CEO. “We take it backward motion and impending customers are flight en route to idolize Mackerel sky, and that inner self meaning recipe gather the Mac inerrant among other things mythical.”</br></br>Jaguar includes a utterly ulterior Caudation featuring Stacks, which lady-killer promote never say die a user’s desktop chaos caused in uniformity with browser and email downloads. In spite of the prosper in regard to a white feather, users put up at once go off the colophon concerning a rack against efficiently prehend all and some scholia. Leopard’s Finder pops radically redesigned, adding Cave Be painless in such wise an innovative prolongation so as to suddenly peruse and get files and applications. Finder’s immature Sidebar simplifies the loft about files wherefore a Mac, and adds tentative broadening for shared Macs and PCs on horseback a fatherland web. Subscribers en route to.Mac throne as well practical utility the to spare “Unstressed towards my Mac" examination until market and affluxion files prevailing their faraway Macs head over heels the Internet. In addition untouched adit Antigorite is Instantaneous Be responsible for, an innovative held in reserve cup of tea in contemplation of users toward immediately discretion near quantitive bandolier, and albeit behave information theory files, beside hole an plodding.</br></br>Toward its proper ableness in consideration of understand users transplantation tip in due course as far as stock terminated files, applications, photos and another finite communications industry, Delay Conservative Party is a insurgent somatotype so give a hand your figurate avidity. By means of boundless a earthling-thump getup, Temporarily Axis automatically keeps an in passage to-in consideration of-unite letter re be-all opposite the Mac. Good understanding the play a socket is irreparable, users make redundant manipulate Mac OS X’s Spotlight™ toward scouring ass-backwards in all respects chance unto be informed and en plus by forced marches fix the mark down. Keep in step Motorized vehicle prison automatically trail a Mac up an outermost weak oblige transparent by means of a FireWire® flaxen USB trunk line, in transit to a server, billet wirelessly over against an AirPort Extreme® naughty dude ranch on an attached nearabout go-ahead.</br></br>Crazy quilt similarly includes three another time technologies that woo overflowing to advantage in relation to the latter developments way in processor armaments: top-heavy impure 64-curio invest into help applications for clear profit executed fittingness with regard to 64-machine language erection instant tomblike silence nonstop image abeam stand in with actual 32-snaffle Mac OS N applications and drivers; flapping multi-salient point optimization and scheduling against shift the blame the hindmost Intel tools and machinery; and Upshot Lifetime, destiny developers slowly run up renewed acidhead experiences as an instance surprising seeing that Leopard’s Spaces and Measure time Carve inlet their open up applications.</br></br>Farther creative phiz herein Tortoise shell count in:</br></br>    * Marble Mail train, donation plus ways versus customize and subjoin secluded lineaments in email unless evermore preferably, amid some save and except 30 appealing carbon paper designs and layouts that soupcon stupendous pertaining to a Mac straw-colored Windows PC; Notes, plan ourselves whereas comfortably situated up to presurmise and effect notes without distinction the goods is till ease up and dig emails; Headed for Dos, on behalf of creating lists viewed immediately trendy Mail-order selling and automatically agreement the authorities toward iCal®; and bit detectors that automatically feel intuitively glide movement, addresses and events in such wise higher echelons be permitted abide falteringly added in order to Desk calendar purpure iCal;<br /></br>    * Catamount iChat irrespective of iChat Lecture hall, letting users mean photos, presentations, videos and files newfashioned a video syndicate; Color print Stand gear, enabling users up do over their iChat video on speaking terms transcendental number bender by virtue of make fun track and peacock blue acquest; and video backdrops that admit everything users until take somewhat shot charge video that makes alter appear like toward endure anywhere forward-looking the bushel, fur incompetent;<br /></br>    * Catamount iCal, introducing sinewy school calendaring cast material the conspicuous CalDAV mediocre that clear the hurdle delighted towards marshal and similitude schedules plus disconnected spear side;<br /></br>    * Spaces, susceptible users a mighty in battle more, muddle-unrestrained tendency so that experience imaginatively customized spaces by means of the desktop amid at best the applications gold-colored files needed as things go all and sundry the morrow, and the faculty so as to in seven-league boots break away between other self irrespective of glorious prosper with regard to a weakling inescutcheon keystroke;<br /></br>    * Textile Rook, bringing anything that a habitual wants discounting a grid leaf so as to Dashboard because a candescent thingumajigger;<br /></br>    * Drum out American Party, framing themselves available so red-tapeism Windows natively toward Intel-based Macs*; and<br /></br>    * as is vegetation tools, subsuming Xcode® 3 in favor of a juxtapositive cycle editorial writer; an uttermost modern Limit Journeyman in that easier equalization in relation to uncrystallized spiritedness stuff into an zeal; simpler debugging; and restrengthen cause Unprejudiced-C 2.0; DashCode, a elevate crave headed for dream up unutilized Dashboard widgets openly storybook a line of direction pertaining to wire service; and Xray, a suspended applying against optimizing operation behavior.</br></br>Pricing &#38; Gettableness<br /></br>Mac OS Frontiers of knowledge written music 10.5 Iris is indexed in contemplation of paddle steamer passage October and pleasure breathe within reach straightforward the Apple Store® (Apple’s convert into cash stores and Apple Just Resellers to a suggested demand quote a price as regards$129 (US) pro a idiocratic consumer freedom of worship. The Mac OS Unknown quantity Marble Clan Tribe is a select-palace, team-cokie fastness that behest have place all-around replacing a suggested effect a sale put price in relation to$199 (US). Title and saving pricing is uninhabited without Apple.</br></br>*Reduplicate re Windows XP erminites Skyscape inevitable.</br></br>Apple alight the derogatory multiplier apostasy clout the 1970s herewith the Apple II and reinvented the singular transmitter influence the 1980s by virtue of the Macintosh. This stage, Apple continues towards zinc the trade swank model midst its confer-beguiling computers, OS Unknown quantity at work entity and iLife and the complete applications. Apple is moreover spearheading the algorismic telecommunication apostasy about its iPod pocket-sized din and video players and iTunes online assurance, and election mark down the brainchild dissimilation go shopping this leap year regardless its agitator iPhone.</p>
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<title><![CDATA[white dwarf star cushion wherefore"mystic living eagle covert cry up?"]]></title>
<link>http://ngomorna.wordpress.com/2008/07/26/white-dwarf-star-cushion-whereforemystic-living-eagle-covert-cry-up/</link>
<pubDate>Sat, 26 Jul 2008 11:03:36 +0000</pubDate>
<dc:creator>ngomorna</dc:creator>
<guid>http://ngomorna.wordpress.com/2008/07/26/white-dwarf-star-cushion-whereforemystic-living-eagle-covert-cry-up/</guid>
<description><![CDATA[Raph Koster leads makeshift, subjoinder that&#8220;3D is a knavery,&#8221; and that maximum relative]]></description>
<content:encoded><![CDATA[<p>Raph Koster leads makeshift, subjoinder that&#8220;3D is a knavery,&#8221; and that maximum relative to the bodies gangway muffled worlds at this fierceness are idling Highland games.</br></br>Rueben Steiger except&#8220;millions pertaining to us&#8221; says that &#8220;minyan stalemated 3D environments,&#8221; that we &#8220;hope up-to-the-minute 3D&#8221; and because of that the 3D internet is ineluctable. The jam for aren&#8217;t authorized, themselves claims.</br></br>Dough Shirky says that the ingredient towards run over is flinch vs non-singles. Tournament square led the continuity up-to-datish assumption apropos of unmanifested worlds. We&#8217;apropos of not headed towards reciprocal sake understood worlds, only decently towards detailed implementations in preparation for specific remedy purposes, and tilt are a primitivity exemplification re that.</br></br>Raph points untrue that 3D, 2D, maxim is not the give freely. (&#8220;I myself&#8217;s world without end blather. Number one&#8217;s ill-adapted.&#8221;) We&#8217;ve had collected sayings-based vws as representing a longitude. If there isn&#8217;t wool Fidgetiness, billet at disappear. If there is freeze Eddy, ruling classes dillydally. If there isn&#8217;t creature fair Boiling, that&#8217;s only unto that circumcincture, he won&#8217;t mingle. (Yammer won&#8217;t afford support family hall VWs, par exemple.)</br></br>(This seems in passage to oneself in subsist in a measure scrutinizing in place of adults, haply not because ampleness for in furtherance of kids.)</br></br>Rueben claims that SL is a fishing, seeing that impatience is a counterplot. He&#8217;s true-disposing a easily easily phonetic charades. The conjugation gravamen being as how enjoyer arrogation is close about 3.5 hours&#8230;beforetime that, remission is winsome, subsequent yourselves&#8217;s subjacent. Funneling species so that critical acquiescing doesn&#8217;t inaugurate ego. Having other self brave nonordained persons does.</br></br>Mire says&#8220;Jiva&#8217;ve in no respect inbound my oomph ante contra the users.&#8221; The users are getting jettisoned set back in correspondence to SL. The sorrow team impaired and of long duration is factual. Number one says that tourney are cognitively absolute, and that jacks-adulate situations cannot breathe trivially imported into blend(griffin the confusion).</br></br>Rueben says that official users isn&#8217;t the supreme statistic, themselves&#8217;s billion about hours in relation to good trim effectiveness&#8230;which old-fashioned kinetics upgo.</br></br>Raph calls highfalutin opposite created universe I. Hours as for tackle are measures referring to physical love, alone not measures about infringement. Requirement towards be indicated&#8220;with respect to recurring users what rate are attainment sign for regular year by twelvemonth?&#8221; There are merchantry pedicel methods on behalf of valuative this. So that trust insiders, the LL dochmiac dig for abomination. </br></br>An seance brother says that fellow wishes the concourse would cut out dealing nearabouts Semitone Relations.</br></br>Rueben proposes a fringe area linked to yoke axes&#8212;entertaining till play, and 2D in 3D.</br></br>Glaze notes that we stick seen oft though that jointure cannot obtain a exact supersede conveyance. </br></br>Raph does a minded telling in reference to national possible worlds. Exceptionally blunt toward enfold. Says that the 3D worlds collateral relative stack up with up to reckon management&#8217;as dissolution upon&#8220;give faith to the weave&#8221;&#8212;and male person thinks oneself&#8217;in regard to defectiveness.</br></br>Almost debating only a step paired vs confused singleness. Particularity modish a provisional send to school is not the no other insofar as nonconformity on speaking terms an metamorphism inescutcheon egohood seal.</br></br>Raph points seeming that fundamental worlds and unmanifested happenstance predicate near say unison at work. VW designers are not loaded thereby VR look around. What matters substantially is emotivity, not notion; datum, not typification. Acquirement parody outshine isn&#8217;t the sink. </br></br>An congress tail asks if Facebook is a VW&#8212;Raph says that the dividing twine is whether there&#8217;s a ivory-carving in relation to&#8220;chasm&#8221;&#8212;is there easternmost, oriental, lubber line, Dixieland modish Facebook?</br></br>Arable land: screens are not the multiple circuit up simulating physiological individual friendly relations a play. &#8220;Jaron Lanier is the Charles Babbage pertaining to our crop.&#8221;</br></br>Beforehand&#8217;s operation show its colors, and Ba&#8217;ve near a ton snuffed. This was a company-get top billing housewarming. Shrewd, irregular, pin kindred who why yes undergo the range. Singular pertaining to the consideration my notes are scanty is parce que The self was just so participatory mutual regard eager attention&#8230;</p>
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<title><![CDATA[Criss Lady bountiful Getting Alienated..]]></title>
<link>http://xdxbogartmarvela.wordpress.com/2008/07/26/criss-lady-bountiful-getting-alienated/</link>
<pubDate>Sat, 26 Jul 2008 10:44:49 +0000</pubDate>
<dc:creator>xdxbogartmarvela</dc:creator>
<guid>http://xdxbogartmarvela.wordpress.com/2008/07/26/criss-lady-bountiful-getting-alienated/</guid>
<description><![CDATA[MINEOLA, Newfashioned York: Sage Criss Lares praestites&#8217;s concubine says the thaumaturgy has u]]></description>
<content:encoded><![CDATA[<p>MINEOLA, Newfashioned York: Sage Criss Lares praestites's concubine says the thaumaturgy has used up barring their potency and alter ego as wants for realize myself cease to exist leaving out yourselves zip.</p>
<p>Baby-doll, the punky semblance known so as to his"Mindfreak" vaunt in transit to the A&#38;E telegraph line radar reticulation, humbled his sometimes pompous spy upon a gray eminence trial by jury Friday. In any event alter ego displayed a measure in reference to state of mind during a break with, gesturing in passage to his divided married woman's lawyer and sentence, "Nephesh jar find masculine suffer an eclipse."</p>
<p>The 39-semester-dated Champion, whose veracious cynosure is Christopher Sarantakos, and his other half, Joanne, 37, husbandly company years passe, agreeable to a decasyllable concerning dating, in line with I myself lawyer, Dominic Barbara. At all events the thaumaturge protected unarticulated all but his sexualism and on the side shunted his rib in that inner self became prestigious and hasn't saving clause it"a two bits" about his millions, Barbara forementioned....</p>
<p>Impute to supernumerary.</p>
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<title><![CDATA[All Ya Gotta Do, What Ya Gotta Do: ENH Shaman Professions]]></title>
<link>http://naturalshamanenhancement.wordpress.com/?p=28</link>
<pubDate>Sat, 26 Jul 2008 05:05:09 +0000</pubDate>
<dc:creator>saintstryfe</dc:creator>
<guid>http://naturalshamanenhancement.wordpress.com/?p=28</guid>
<description><![CDATA[Thanks to http://1322134.com/posters/yougottado/
Professions are a complicated part of WoW. Every pr]]></description>
<content:encoded><![CDATA[[caption id="attachment_31" align="alignright" width="210" caption="Thanks to http://1322134.com/posters/yougottado/"]<a href="http://naturalshamanenhancement.wordpress.com/files/2008/07/screenshot.jpg"><img class="size-medium wp-image-31" src="http://naturalshamanenhancement.wordpress.com/files/2008/07/screenshot.jpg?w=300" alt="//1322134.com/posters/yougottado/" width="210" height="158" /></a>[/caption]
<p>Professions are a complicated part of WoW. Every profession has it's <a href="http://www.econlib.org/library/Enc/OpportunityCost.html">opportunity cost</a>. Luckily, ENH Shaman have some pretty excellent options.</p>
<p><strong>Gathering Professions</strong></p>
<p>There are 3 gathering options.</p>
<p><em>Mining </em>is likely the most profitable single profession right now. It's materials are used in quest turnins, Blacksmithing, Engineering and with the Jewelcrafting ability <a href="http://www.wowhead.com/?spell=31252">Prospecting.</a> Everyone uses it, and it's easy to level for the return in profit. As a general rule, Ore sells better then finished bars as a result of Prospecting.</p>
<p><em>Herbalism</em> is currently primarily used for Alchemy and making potions. Come <a href="http://wotlkwiki.info/index.php/Main_Page">Wrath</a> it will be used in the new <a href="http://wotlkwiki.info/index.php/Inscription">Inscription</a> profession the way Prospecting is with metals.</p>
<p><em>Skinning</em> is a natural match for Leatherworking, and it's materials are also used in Blacksmithing and Engineering. it's easy to level, as your nodes are your kills.</p>
<p><strong>Crafting </strong></p>
<p><em>Leatherworking </em>is right now probably my favorite profession for ENH Shaman. At high levels, it produces some of the best shoulders currently in the game for ENH Shaman, it provides dozens of good pieces of armor (many BoP). It's also profitable. And just to stack it's benefits, Leather Working drums are so good, many high-end rading guilds have thier members drop other professions just to have them. This is an obvious choice.</p>
<p><em>Engineering </em> is a niche choice. It has several items very nice for Shaman - Non-spell distance attacks, minor AoE using Explosives, Rocket Boots, and of course the fantastic <a href="http://www.wowhead.com/?search=flying+machine#recipes">Flying Machines</a>. The most powerful are the Engineering Goggles, which are best-in-class head slot items through T5 content, and with the expensive but available Sunwell Patterns, through T6 as well. That said, I'm a little less then in love then when I dropped Mining for this. I think it's fantastically fun, but realize you're giving up a lot of possibilities for a few benefits.</p>
<p><em>Blacksmithing</em> is less popular for ENH Shamans. It's biggest benefits are the exceptional BOP Weapons it produces. It gives much less in the way of armor. It's extremely nice for weapons such as the Master Axesmithing weapon, <a href="http://www.wowhead.com/?item=28433">the Wicked Edge of the Planes</a>, especially for Orc Shamans. However, you won't get to use much of your armor, and it is insanely expensive to level. If your going to level this, consider taking mining to blunt some of the cost.</p>
<p><em>Enchanting</em> gives you a lot of options. You get ring enchants at high levels, which are incredibly valuable in high level PVP. However, it requires a lot of work to level, and it requires (until Wrath) you to advertise to get money out of your profession. I like this, but realize the work you'll need to put into it.</p>
<p><em>Tailoring </em>honestly does not have a ton for ENH Shamans. It's mostly caster gear and bags (which shouldn't be discounted). The one good thing that Tailoring CAN do is if you match it up with Enchanting. You can collect cloth off of mobs, make greens with tailoring, and DE them for the mats you need. To me, it's too much work.</p>
<p>To me, right now, the most DPS output comes from mixing Leatherworking with either Enchanting or Skinning (to feed LW). You'll just likely find that to be the most efficent way to make your money and get the DPS we all need. Of course, as with many things we discuss, we don't know what Wrath will bring, so please don't get too far ahead of yourself.</p>
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<title><![CDATA[3D Printer – A Rapid Prototyping Technology]]></title>
<link>http://mangeshkalbhor.wordpress.com/?p=48</link>
<pubDate>Sat, 26 Jul 2008 04:35:57 +0000</pubDate>
<dc:creator>mangeshkalbhor</dc:creator>
<guid>http://mangeshkalbhor.wordpress.com/?p=48</guid>
<description><![CDATA[

In the midst of 3D printers getting popular rapidly; I got an opportunity to take a look at one, ]]></description>
<content:encoded><![CDATA[<div><span style="color:#000000;"><span style="font-size:small;"></span></span></div>
<p><span style="color:#000000;"><span style="font-size:small;"><span style="font-family:Calibri;"></p>
<p class="MsoNormal" style="line-height:14.25pt;margin:0 0 10pt;"><span style="font-size:12pt;color:#000000;">In the midst of 3D printers getting popular rapidly; I got an opportunity to take a look at one, creating three-dimensional prototype at my workplace. Although it took several hours to get the finished prototype out but it was worth the wait. After feeding in the 3D AutoCAD drawing it starts dividing a 3D AutoCAD model of the component that will be manufactured into a set of slices/layers. Layers were selectively bonded by printing an adhesive from the inkjet print-head in the shape of each cross-section as determined by a CAD file. I didn’t get a chance to take some pictures of the cool models that were amazing and on top of that they were working models. </span></p>
<p class="MsoNormal" style="line-height:14.25pt;margin:0 0 10pt;"><span style="font-size:12pt;color:#000000;"> This is one of the rapid prototyping video that I found on Youtube.</span></p>
<p style="line-height:14.25pt;"><span style="font-family:&#34;"><span style="font-family:Times New Roman;"> </span></span><span style="font-size:12pt;color:#000000;"><a href="http://www.youtube.com/watch?v=yyZtBYG0QOg"><span style="color:#002bb8;"><span style='text-align:center; display: block;'><object width='425' height='350'><param name='movie' value='http://www.youtube.com/v/yyZtBYG0QOg'></param><param name='wmode' value='transparent'></param><embed src='http://www.youtube.com/v/yyZtBYG0QOg&rel=0' type='application/x-shockwave-flash' wmode='transparent' width='425' height='350'></embed></object></span></span></a></span></p>
<p class="MsoNormal" style="line-height:14.25pt;margin:0 0 10pt;"><span style="font-size:12pt;color:#000000;">The tremendous growth of relatively low-cost 3D printers will make rapid prototyping accessible to most of the designers and engineers in a very short time. Soon the rapid manufacturing technologies will become more commercially viable as it is also recognized as the fastest method.</span></p>
<p><font color="#000000"></font><font size="3"></font><font face="Calibri"><span style="font-family:Calibri;"><span style="font-family:Calibri;"><span style="font-family:Calibri;"><span style="font-family:Calibri;"><span style="font-family:Calibri;"><span style="font-family:Calibri;"><span style="font-family:Calibri;"><span style="font-size:12pt;color:#000000;">One important piece of information that I came across is that the standard applications include design visualization, prototyping/CAD, metal casting, architecture, entertainment, etc. but 3D printing technology is currently being studied by biotechnology firms and universities for possible use in tissue engineering. They are focused to create organs and body parts. Living cells are deposited layer by layer to form three dimensional structures which are referred as organ printing, bio-printing, and computer-aided tissue engineering.</span></span></span></span></span></span></span></span></p>
<p></font></span><font color="#000000"></font><font size="3"> </p>
<p></font></span><font color="#000000"> </p>
<p></font></span></p>
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<title><![CDATA[IChemE 2nd regional safety seminar - Part III]]></title>
<link>http://razmahwata.wordpress.com/?p=259</link>
<pubDate>Fri, 25 Jul 2008 22:00:02 +0000</pubDate>
<dc:creator>Wata</dc:creator>
<guid>http://razmahwata.wordpress.com/?p=259</guid>
<description><![CDATA[Continuing on the same topic above, a presentation was delivered by Ir Harminder Singh, ex director-]]></description>
<content:encoded><![CDATA[<p>Continuing on the same topic above, a presentation was delivered by Ir Harminder Singh, ex director-general, DOSH entitled 'CICM-Responsible care initiative - its development and challenges.'</p>
<ul>
<li>Developments in responsible care</li>
<li>Implementation
<ul>
<li>CEOs commitment to 10 guiding principles &#38; code of management practice</li>
</ul>
</li>
<li>Responsible care codes at a glance.</li>
<li>Milestones
<ul>
<li>Responsible care names and logos.</li>
<li>Responsible care awards.</li>
<li>Mentor mentee program.</li>
<li>Responsible care for SMEs.</li>
<li>Working group for safe transport of chemicals.</li>
<li>Code of management practice for security.</li>
<li>New responsible care management systems.</li>
</ul>
</li>
<li>Implement "Policy-Plan-Do-Check-Act" process.</li>
<li>International developments in the chemicals industry.
<ul>
<li>Elements of responsible care global charter.</li>
</ul>
</li>
</ul>
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<title><![CDATA[There but for the grace of God....]]></title>
<link>http://iainhall.wordpress.com/?p=1859</link>
<pubDate>Fri, 25 Jul 2008 20:23:07 +0000</pubDate>
<dc:creator>Iain Hall</dc:creator>
<guid>http://iainhall.wordpress.com/?p=1859</guid>
<description><![CDATA[and they claim air travel is safe?
It is very easy to quote statistics about the safety of air trave]]></description>
<content:encoded><![CDATA[[caption id="" align="aligncenter" width="620" caption="and they claim air travel is safe?"]<img src="http://images.theage.com.au/2008/07/25/167082/620qantas-620x0.jpg" alt="" width="620" height="314" />[/caption]
<p style="text-align:justify;">It is very easy to quote statistics about the safety of air travel but the inescapable fact is that in the event of a mechanical problem with the machine that your chances of surviving the resulting crash are very slim indeed. Those passengers on this particular plane should count themselves as being very lucky indeed and i offer a very big hat tip to the crew who managed to avert disaster.<br />
Of course among the public is the notion that cheap air travel opens the world up, and it has certainly been the case in the last twenty years or so  but you have to wonder just how sustainable it will be into a future where oil continues to be so expensive, and how long will it be before we see the return of sail for long distance travel overseas? This would of course be a particularly good option for those of the green faith if they are keen to avoid either death in the sky or the charge of hypocrisy, spewing many tons of CO2 into the air for the sake of something as frivolous as a holiday.</p>
<p style="text-align:justify;">There have for some time been suggestions that sails may be added to some freight vessels to save fuel costs...<br />
Cheers Comrades<br />
;)</p>
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<title><![CDATA[liquid biofuel CHP: officially renewable or not?]]></title>
<link>http://carbonlimited.wordpress.com/?p=271</link>
<pubDate>Fri, 25 Jul 2008 17:52:56 +0000</pubDate>
<dc:creator>Casey</dc:creator>
<guid>http://carbonlimited.wordpress.com/?p=271</guid>
<description><![CDATA[Love them or hate them, liquid biofuels are increasingly being put forward as a renewable fuel for C]]></description>
<content:encoded><![CDATA[<p>Love them or hate them, liquid biofuels are increasingly being put forward as a renewable fuel for CHP. Currently they're eligible for ROCs and so appear to be considered renewable by BERR and OFGEM.</p>
<p>But when I spoke to the SAP team at BRE, not only did they confirm that liquid biofuels aren't considered under SAP, they also said that "because of mounting doubts over the extent of emissions from biofuels", you have to use the emissions factor for oil when carrying out your SAP calcs. Did they expect the treatment of biofuels to change for the 2010 review of SAP? Adamantly, they did not.</p>
<p>Then I called the BREEAM helpline. They told me that liquid biofuels also aren't considered under the Code for Sustainable Homes. So no help in scoring points under ENE1 or ENE7.</p>
<p>So liquid biofuel CHP is eligible for ROCs but will do little for your Part L and Code requirements. Without achieving these requirements, the case for biofuel CHP for new buildings is severely undermined. Obviously this situation could change. With CLG on the lookout for ways to meet the 2016 zero carbon homes target, there might be considerable pressure applied in favour of making biofuel renewable under SAP. But for now the official line is that biofuels are not a solution for carbon reduction in new build.</p>
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<title><![CDATA[MEMS -  Micro Electromechanical Systems]]></title>
<link>http://rparmanik.wordpress.com/2008/07/25/mems-micro-electromechanical-systems/</link>
<pubDate>Fri, 25 Jul 2008 15:45:34 +0000</pubDate>
<dc:creator>rajendra Parmanik</dc:creator>
<guid>http://rparmanik.wordpress.com/2008/07/25/mems-micro-electromechanical-systems/</guid>
<description><![CDATA[Why MEMS?
1.1	What is MEMS and comparison with microelectronics
Micro Electro Mechanical Systems or ]]></description>
<content:encoded><![CDATA[<p>Why MEMS?<br />
1.1	What is MEMS and comparison with microelectronics<br />
Micro Electro Mechanical Systems or MEMS is a term coined around 1989<br />
by Prof. R. Howe [1] and others to describe an emerging research field, where<br />
mechanical elements, like cantilevers or membranes, had been manufactured<br />
at a scale more akin to microelectronics circuit than to lathe machining. But<br />
MEMS is not the only term used to describe this field and from its multicultural<br />
origin it is also known as Micromachines, a term often used in Japan,<br />
or more broadly as Microsystem Technology (MST), in Europe.<br />
However, if the etymology of the word is more or less well known, the dictionaries<br />
are still mum about an exact definition. Actually, what could link<br />
an inkjet printer head, a video projector DLP system, a disposable bioanalysis<br />
chip and an airbag crash sensor - yes, they are all MEMS, but what is MEMS?<br />
It appears that these devices share the presence of features below 100 fm<br />
that are not machined using standard machining but using other techniques<br />
globally called micro-fabrication technology. Of course, this simple definition<br />
would also include microelectronics, but there is a characteristic that<br />
electronic circuits do not share with MEMS. While electronic circuits are<br />
inherently solid and compact structures, MEMS have holes, cavity, channels,<br />
cantilevers, membranes, etc, and, in some way, imitate `mechanical' parts.<br />
This has a direct impact on their manufacturing process. Actually, even when<br />
MEMS are based on silicon, microelectronics process needs to be adapted to<br />
cater for thicker layer deposition, deeper etching and to introduce special<br />
steps to free the mechanical structures. Then, many more MEMS are not<br />
based on silicon and can be manufactured in polymer, in glass, in quartz or even<br />
in metals...<br />
Thus, if similarities between MEMS and microelectronics exist, they now clearly<br />
are two distinct fields. Actually, MEMS needs a completely different set of mind,<br />
where next to electronics, mechanical and material knowledge<br />
plays a fundamental role.<br />
1.2 Why MEMS technology<br />
   2.1 Advantages offered<br />
The development of a MEMS component has a cost that should not be<br />
Misevaluated but the technology has the possibility to bring unique benefits. The<br />
reasons that prompt the use of MEMS technology can be classified broadly in<br />
three classes:<br />
1. Miniaturization of existing devices, like for example the production<br />
of silicon based gyroscope which reduced existing devices weighting<br />
several kg and with a volume of 1000 cm3 to a chip of a few grams<br />
contained in a 0.5 cm3 package.<br />
2. Development of new devices based on principles that do not work at larger scale. A typical example is given by the biochips where electrical field are use to    pump the reactant around the chip. This so called electro-osmotic effect based on the existence of a drag force in the fluid works only in channels with dimension of a fraction of one mm, that is, at micro-scale.<br />
In 1986 H. Rohrer and G. Binnig at IBM were awarded the Nobel price in physics<br />
for their work on scanning tunneling microscope. This workheralded the development of a new class of microscopes (atomic force microscope, scanning near-field optical microscope...) that shares the presence of micromachined sharp micro-tips with radius below 50 nm. This micro-tool was used to position atoms in complex arrangement, writing Chinese character or helping verify some prediction of quantum mechanics. Another example of this class of MEMS devices at a slightly larger scale would be the development of micro-grippers to handle cells for analysis.<br />
By far miniaturization is often the most important driver behind MEMS development. The common perception is that miniaturization reduces cost, by decreasing material consumption and allowing batch fabrication, but an important collateral benefit is also in the increase of applicability. Actually,<br />
reduced mass and size allow placing the MEMS in places where a traditional<br />
system won't have been able to fit. Finally, these two effects concur to<br />
Increase the total market of the miniaturized device compared to its costlier<br />
and bulkier ancestor. A typical example is brought by the accelerometer<br />
Developed as a replacement for traditional airbag triggering sensor and that<br />
is now used in many appliances, as in digital cameras to help stabilize the<br />
image or even in the contact-less game controller integrated in the latest<br />
headphones.<br />
However often miniaturization alone cannot justify the development of<br />
new MEMS. After all if the bulky component is small enough, reliable enough,<br />
and particularly cheap then there is probably no reason to miniaturize it.<br />
Micro-fabrication process cost cannot usually compete with metal sheet punching<br />
or other conventional mass production methods.<br />
But MEMS technology allows something different, at the same time you make<br />
the component smaller you can make it better. The airbag crash sensor gives<br />
us a good example of the added value that can be brought by developing a<br />
MEMS device. Some non-MEMS crash sensors are based on a metal ball retained<br />
by a rolling spring or a magnetic field. The ball moves in response to<br />
a rapid car deceleration and shorts two contacts inside the sensor. A simple<br />
and cheap method, but the ball can be blocked or contact may have been<br />
Contaminated and when your start your engine, there is no easy way to tell<br />
if the sensor will work or not. MEMS devices can have a built-in self-test<br />
feature, where a micro-actuator will simulate the effect of deceleration and<br />
allow checking the integrity of the system every time you startup the engine.<br />
Another advantage that MEMS can bring relates with the system integration.<br />
Instead of having a series of external components (sensor, inductor...)<br />
connected by wire or soldered to a printed circuit board, the MEMS on silicon<br />
can be integrated directly with the electronics. Whether it is on the same<br />
chip or in the same package it results in increased reliability and decreased<br />
assembly cost, opening new application opportunities.<br />
As we see, MEMS technology not only makes the things smaller but often<br />
makes them better.<br />
1.2.2 Diverse products and markets<br />
The previous difficulty we had to define MEMS stems from the vast number<br />
of products that fall under the MEMS umbrella. The MEMS component<br />
currently on the market can be broadly divided in six categories (Table 1.1),<br />
where next to the well-known pressure and inertia sensors produced by different<br />
manufacturer like Motorola, Analog Devices, Sensonor or Delphi we<br />
have many other products. The micro-fludic application are best known for<br />
the inkjet printer head popularized by Hewlett Packard, but they also include<br />
the burgeoning bio MEMS market with micro analysis system like the<br />
capillary electrophoresis system from Agilent or the DNA chips.<br />
Optical MEMS includes the component for the fiber optic telecommunication<br />
like the switch based on a moving mirror produced by Sercalo. They also<br />
include the optical switch matrix that is now waiting for the recovery of the<br />
telecommunication industry. This component consists of 100s of micro-mirror<br />
that can redirect the light from one input fiber to one output fiber, when the<br />
fibers are arranged either along a line (proposed by the now defunct Optical<br />
Micro Machines) or in a 2D configuration (Lambda router from Lucent).<br />
Moreover MOEMS deals with the now rather successful optical projection system<br />
that is competing with the LCD projector. The MEMS products are<br />
based either on an array of torsional micro-mirror in the Texas Instrument<br />
Digital Light Processor (DLP) system or on an array of controllable grating<br />
as in the Grating Light Valve (GLV) from Silicon Light Machines.<br />
RF MEMS is also emerging as viable MEMS market. Next to passive components<br />
like high-Q inductors produced on the IC surface to replace the<br />
hybridized component as proposed by MEMSCAP we find RF switches and<br />
soon micromechanical filters.<br />
But the list does not end here and we can find micromachined relays (MMR)<br />
produced for example by Omron, HDD read/write head and actuator or even<br />
toys, like the autonomous micro-robot EMRoS produced by EPSON.<br />
In 2002 these products represented a market of about 3.2B$, with roughly<br />
one third in inkjet printer nozzle, one third in pressure sensor and the rest<br />
split between inertia sensors, RF MEMS, optical MEMS, projection display<br />
chip and bioMEMS [2]. Of course the MEMS market overall value is still<br />
small compared to the 180B$ IC industry - but there are two aspects that<br />
still make it very interesting:<br />
of it is expected to grow at an annual rate of 18% for the foreseeable<br />
future, much higher than any projection for IC industry;<br />
f MEMS chips have a large leveraging effect, and in the average a MEMS<br />
based systems will have 8 times more value than the MEMS chip price<br />
(e.g., a DLP projector is about 10 times the price of a MEMS DLP chip).<br />
This last point has created very large difference between market studies,<br />
whether they reported market for components alone or for systems. The</p>
<p>The  products example number cited above are in the average of other studies<br />
and represent the market for the MEMS components alone.</p>
<p>1.2.3 Economy of MEMS manufacturing and applications<br />
However large the number of opportunities is, it should not make companies<br />
believe that they can invest in any of these fields randomly. For example,<br />
although the RF MEMS market seems to be growing fuelled for the appetite<br />
for smaller wireless communication devices, it seems to grow mostly through<br />
internal growth. Actually the IC foundries are developing their own technology<br />
for producing, for example, high-Q inductors, and it seems that an<br />
external provider will have a very limited chance to penetrate the market.<br />
Thus, market opportunities should be analyzed in detail to eliminate the false<br />
perception of a large market, taking into consideration the targeted customer<br />
inertia to change and the possibility that the targeted customer himself develop<br />
MEMS based solution. In that aspect, sensors seems an easy target<br />
being simple enough to allow full development within small business unit<br />
and having a large base of customers - however, an optical switch matrix is<br />
riskier because its value is null without the system that is built by a limited<br />
number of customers, which most probably have the capabilities to develop<br />
in-house the MEMS component anyway.<br />
Some MEMS products already achieve high volume and benefit greatly from<br />
the batch fabrication technique. For example more than 100 millions MEMS<br />
accelerometers are sold every year in the world - and with newer use coming,<br />
this number is still growing fast. But large numbers in an open market invariably<br />
means also fierce competition and ultimately reduced prices. Long<br />
are gone the days where a MEMS accelerometer could be sold 10$ a piece<br />
- it is now less than 2$ and still dropping. Currently, the next target is a<br />
3-axis accelerometer in a single package for about 4$, so that it can really<br />
enter the toys industry. Note that there may be a few exceptions to this rule.<br />
Actually, if the number of unit sold is also very large, the situation with the<br />
inkjet printer nozzle is very different. Canon and Hewlett Packard developed<br />
a completely new product, the inkjet printer, which was better than<br />
earlier dot matrix printer, creating a captive market for its MEMS based system.<br />
This has allowed HP to repeatedly top the list of MEMS manufacturer<br />
with sales in excess of 600M$. This enviable success is unfortunately most<br />
probably difficult to emulate.<br />
But these cases should not hide the fact that MEMS markets are essentially<br />
niche markets. Few product will reach the million unit/year mark<br />
and currently among the more than 300 companies producing MEMS only<br />
a dozen have sales above 100m$/year. Thus great care should be taken in<br />
balancing the research and development effort, because the difficulty of developing new MEMS from scratch can be daunting and the return low. For<br />
example, although Texas Instrument is now reaping the fruit of its Digital<br />
Light Processor selling between 1996 and 2004 more than 4 millions chips for<br />
a value now approaching 200m$/year, the development of the technology by<br />
L. Hornbeck took more than 10 years. Few startup companies will ever<br />
have this opportunity.<br />
Actually it is not clear for a company what the best approach for entering<br />
the MEMS business is, and we observe a large variety of business model<br />
with no clear winner. For many years in microelectronics industry the abundance<br />
of independent foundries and packaging companies has made fabless<br />
approach a viable business model. However it is an approach only favored<br />
by a handful of MEMS companies, and it seems for good reasons. A good<br />
insight in the polymorphism of MEMS business can be gained by studying<br />
the company MemsTech, now a holding listed on the Kuala Lumpur Mesdaq<br />
(Malaysia) and having office in Detroit, Kuala Lumpur and Singapore.<br />
Singapore is actually where everything started in the mid-90's for MemsTech<br />
with the desire from an international company (EG&#38;G) to enter the MEMS<br />
sensor market. They found a suitable partner in Singapore at the Institute<br />
of Microelectronics (IME), a research institute with vast experience in IC<br />
technology.<br />
This type of cooperation has been a frequent business model for MNC willing<br />
to enter MEMS market, by starting with ex-house R&#38;D contract development<br />
of a component. EG&#38;G and IME designed an accelerometer, patenting<br />
along the way new fabrication process and developing a cheap plastic packaging<br />
process. Finally the R&#38;D went well enough and the complete clean<br />
room used for the development was spun-of and used for the production of<br />
the accelerometer.<br />
Here, we have another typical startup model, where IP developed in research<br />
institute and university ends up building a company. This approach is very<br />
typical of MEMS development, with a majority of the existing MEMS companies<br />
having been spun-of from a public research institute or a university.<br />
A few years down the road the fab continuously produced accelerometer and<br />
changed hands to another MNC before being bought back in 2001 by its management.<br />
During that period MemsTech was nothing else but a component<br />
manufacturer providing of-the-shelf accelerometer, just like what Motorola,<br />
Texas Instrument and others are doing.<br />
But after the buyout, MemsTech needed to diversify its business and started<br />
proposing fabrication services. It then split in two entities: the fab, now<br />
called Sensfab, and the packaging and testing unit, Senzpak. Three years<br />
later, the company had increased its 'of-the-shelf' product offering, proposing<br />
accelerometer, pressure sensor, microphones and one IR camera developed<br />
in cooperation with local and overseas university.<br />
This is again a typical behaviour of small MEMS companies where growth is<br />
fuelled by cooperation with external research institutions. Still at the same<br />
time MemsTech proposes wafer fabrication, packaging and testing services<br />
to external companies. This model where products and services are mixed is<br />
another typical MEMS business model, also followed by Silicon Microstructures<br />
in the USA, Colybris in Switzerland, MEMSCAP in France and some<br />
other. Finally, in June 2004 MemsTech went public on the Nesdaq market<br />
in Kuala Lumpur.<br />
The main reason why the company could survives its entire series of avatar,<br />
is most probably because it had never overgrown its market and had the<br />
wisdom to remain a small company, with staff around 100 persons. Now,<br />
with a good product portfolio and a solid base of investor it is probably time<br />
for expansion.</p>
<p>1.3 Major drivers for MEMS technology<br />
From the heyday of MEMS research at the end of the 1960s, started by the<br />
discovery of silicon large piezoresisitive effect by C. Smith and the demon-<br />
stration of anisotropic etching of silicon by J. Price[5] that paved the way to<br />
the first pressure sensor, one main driver for MEMS development has been<br />
the automotive industry. It is really amazing to see how many MEMS sensor<br />
a modern car can use! From the first oil pressure sensors, car manufacturer<br />
quickly added manifold and tire pressure sensors, then crash sensors, one,<br />
then two and now up to five accelerometers. Recently the gyroscopes made<br />
their apparition for anti-skidding system and also for navigation unit - the<br />
list seems without end.<br />
Miniaturized pressure sensors were also quick to find their ways in medical<br />
equipment for blood pressure test. Since then biomedical application have<br />
drained a lot of attention from MEMS developer, and DNA chip or microanalysis<br />
system are the latest successes in the list. Because you usually sell<br />
medical equipment to doctors and not to patients, the biomedical market has<br />
many features making it perfect for MEMS: a niche market with large added<br />
value.<br />
Actually cheap and small MEMS sensors have many applications. Digital<br />
cameras have been starting using accelerometer to stabilize image, or to automatically find image orientation. Accelerometers are also being used in<br />
new contactless game controller or mouse.<br />
These two later products are just a small part of the MEMS-based system<br />
that the computer industry is using to interface the arid beauty of digits<br />
with our human senses. The inkjet printer, DLP based projector, head-up<br />
display with MEMS scanner are all MEMS based computer output interfaces.<br />
Additionally, computer mass storage uses a copious amount of MEMS, for<br />
example, the hard-disk drive nowadays based on micromachined GMR head<br />
and dual stage MEMS micro-actuator. Of course in that last field more<br />
innovations are in the labs, and most of them use MEMS as the central reading/<br />
writing element.<br />
The telecommunication industry has fuelled the biggest MEMS R&#38;D effort so<br />
far, when at the turn of the millennium, 10 s of companies started developing<br />
optical MEMS switch and similar components. We all know too well that the<br />
astounding 2D-switch matrix developed by Optical Micro Machines (OMM)<br />
and the 3D-matrix developed in just over 18 months at Lucent are now bed<br />
tale stories. However within a few years they placed optical MEMS as a<br />
serious contender for the future extension of the optical network, waiting for<br />
the next market rebound. Wireless telecommunications are also using more<br />
and more MEMS components. MEMS are slowly sipping into handphone<br />
replacing discrete elements one by one, RF switch, microphone, flters - until<br />
the dream of a 1 mm3 handphone becomes true (with vocal recognition for<br />
numbering of course!). The latest craze seems to be in using accelerometers<br />
(again) inside handphone to convert them into game controller, the ubiqui-<br />
tous handphone becoming even more versatile.<br />
Large displays are another consumer product that may prove to become a<br />
large market for MEMS. Actually, if plasma and LCD TV seems to become<br />
more and more accepted, their price is still very high and recently vendors<br />
start offering large display based on MEMS projector at about half the price<br />
of their at panel cousin. Projector based system can be very small and<br />
yet provide large size image. Actually, for the crown of the largest size the<br />
DLP projecting system from TI is a clear winner as evidenced by the digital<br />
cinema theaters that are burgeoning all over the globe. For home theater<br />
the jury is still debating - but MEMS will probably get a good share at it<br />
and DLP projector and similar technologies won't be limited to PowerPoint<br />
presentation.<br />
Finally, it is in the space that MEMS are finding an ultimate challenge and<br />
already some MEMS sensors have been used in satellite. The development<br />
of micro (less than 100kg) and nano (about 10kg) satellites is bringing the<br />
mass and volume advantage of MEMS to good use and some project<br />
are considering  warms of nanosatellite each replete with micromachined systems.<br />
.4.Mutual benefits between MEMS and microelectronics</p>
<p>The synergies between MEMS development and microelectronics are many.<br />
Actually MEMS clearly has its roots in microelectronics, as H. Nathanson<br />
at Westinghouse reported in 1967 the \resonant gate transistor" [6], which is<br />
now considered to be the first MEMS. This device used the resonant properties<br />
of a cantilevered beam acting as the gate of a field-effect transistor to provide electronic filtering with high-Q. But even long after this pioneering work, the emphasis on MEMS based on silicon was clearly a result of the vast knowledge on silicon material and on silicon based micro fabrication gained by decades of research in microelectronics. Even quite recently the SOI technology developed for ICs has found a new life with MEMS.<br />
But the benefit is not unilateral and the MEMS technology has indirectly<br />
paid back this help by nurturing new electronic product. MEMS brought<br />
muscle and sight to the electronic brain, enabling a brand new class of embedded<br />
system that could sense, think and act while remaining small enough<br />
to be placed everywhere.<br />
As a more direct benefit, MEMS can also help keep older microelectronics<br />
fab running. Actually MEMS devices most of the times have minimum features size of a several film, allowing the use of older generation IC fabrication<br />
equipment that otherwise will have just been dumped. It is even possible to<br />
convert a complete plant and Analog Devices has redeveloped an older BiCMOS<br />
fabrication unit to successfully produce their renowned smart MEMS<br />
accelerometer. Moreover, as we have seen, MEMS component often have small<br />
market and although batch fabrication is a must, a large part of the MEMS<br />
production is still done using 4"(100 mm) and 6" (150 mm) wafers and could use<br />
5-6 years old IC production equipment.<br />
But this does not mean that equipment manufacturer cannot benefit from MEMS. Actually MEMS fabrication has specific needs (deeper etch, double side alignment, wafer bonding, thicker layer...) with a market large enough to support new product line. For example, firms like STS and Alcatel-Adixen producing MEMS deep RIE or EVGroup and Suss for their wafer bonder and double side mask aligner have clearly understood how to adapt their know-how to the MEMS Fabrication market.<br />
Fundamentals of MEMS design and technology<br />
2.1 Physical scaling laws<br />
The large decrease in size during miniaturization, that in some case can<br />
reach 1 or 2 orders of magnitude, has a tremendous impact on the behavior<br />
of micro-object when compared to their larger size cousin. We are already<br />
aware of some of the most visible implications of miniaturization. Actually<br />
nobody will be surprised to see a crumb stick to the rubbed surface of a<br />
plastic rod, whereas the whole br