Mechanical:Cryogenic Grinding

Cryogenic grinding, also known as freezer milling, freezer grinding, and cryomilling, is the act of cooling or chilling a material and then reducing it into a small particle size. For example, thermoplastics are difficult to grind to small particle sizes at ambient temperatures because they soften, adhere in lumpy masses and clog screens. When chilled by dry ice, liquid carbon dioxide or liquid nitrogen, the thermoplastics can be finely ground to powders suitable for electrostatic spraying and other powder processes. Cryogenic grinding of plant and animal tissue is a technique used by microbiologists. Samples that require extraction of nucleic acids must be kept at ?80 °C or lower during the entire extraction process. For samples that are soft or flexible at room temperature, cryogenic grinding may be the only viable technique for processing samples. A number of recent studies report on the processing and behavior of nanostructured materials via cryomilling

Mechanical Floating Solar Chimney Technology

To overcome today’s energy crisis, the energy industries can implement the advanced technology like floating solar chimney technology (FSCT). FSCT is quite sustainable and the most abundantly available renewable source of energy when compared to other renewable sources of energy. This technique utilises a greenhouse to trap solar energy from the sun. The objective of present work is to explore the feasibility, principle of operation, power generating capacity and past scenario behind this concept of power generation. This paper also suggests the methodology to overcome the problems. FSCT can be installed in arid, semiarid, and even in grasslands to generate power. Hence this technology would be a boon to the energy crisis.

The basic model of this structure was first built in 1982 and successfully tested for 6 years, in Spain by Prof J. Schlaich. It was a small prototype with 50kw power producing technology. Even with moderate height FSC structures of 650m, is possible the direct production cost to be approximately 45 USD/MWh.The fsc technology is a promising technology that is appropriate for areas such as desert and dry regions where other technologies are not suited because of high cost and unfavorable local conditions. This technology is a fabric structure that can be raised locally and manufactured at any place. The daily power generated by using this technology in desert areas will be proportional to the daily horizontal solar irradiation in that area.

Mechanical: Resource Conservation

Resources are the things from the environment which are useful to human beings. Natural resources are resources we get from nature (example: fossil fuels, water, minerals from soil). The term conservation came into use in the late 19th century and referred to the management, mainly for economic reasons, of valuable natural resources. But conservation of natural resources is now usually embraced in the broader conception of conserving the earth itself by protecting its capacity for self-renewal. Particularly complex are the problems of non-renewable resources such as oil and coal and other minerals in great demand. The growing population, rapid industrialisation and urbanisation have created heavy demand on all these materials. Conservation of resources not only means the protection but also the judicious use of the resources so that they don't get exhausted. Management of the human use of natural resources to provide the maximum benefit to current generations while maintaining capacity to meet the needs of future generations is called Conservation of resources.

Essentiality of resources to satisfy the needs of humans as living organisms is mentioned and so is exhaustibility of most of them. Conservation is the main point of the answer to this resource crisis. Present state of this problem is very alarming and will go fully out of control if we don’t act quickly and spontaneously. This is one of the main problems of civilisation at present and this problem cannot be managed without the help of everyone. And to get everyone’s help at first everyone should be known about the matter. Awareness should be generated and spread among the people. And that’s why this topic has been chosen to be discussed.

Mechanical: Gas Welding

Although the oxyacetylene process has been introduced long time ago it is still applied for its flexibility and mobility. Equipment for oxyacetylene welding consists of just a few elements, the energy necessary for welding can be transported in cylinders.Process energy is obtained from the exothermal chemical reaction between oxygen and a combustible gas, Figure 1.2. Suitable combustible gases are C2H2, lighting gas, H2, C3H8 and natural gas; here C3H8 has the highest calorific value. The highest flame intensity from point of view of calorific value and flame propagation speed is, however, obtained with C2H2. C2H2 is produced in acetylene gas generators by the exothermal transformation of calcium carbide with water, Carbide is obtained from the reaction of lime and car- bon in the arc furnace.C2H2 tends to decompose already at a pressure of 0.2 MPa. Nonetheless, commercial quantities can be stored when C2H2 is dis- solved in acetone.

Acetone disintegrates at a pressure of more than 1.8 MPa, i.e., with a filling pressure of 1.5 MPa the storage of 6m3 of C2H2 is possible in a standard cylinder (40 l). For gas ex- change (storage and drawing of quantities up to 700 l/h) a larger surface is necessary, therefore the gas cylinders are filled with a porous mass (diatomite). Gas consumption during welding can be observed from the weight reduction of the gas cylinder.

Mechanical: Maglev Levitation Trains

The report titled ‘MAGLEV TRAINS’ accomplishes a research on the developing discipline of magnetic levitation and its application to transportation through trains. It provides detailed information about the evolution of maglev science, its progression and improvisation till date. High-speed magnetically levitated ground transportation (maglev) is a new surface mode of transportation, in which vehicles glide above their guideways, suspended, guided, and propelled by magnetic forces. This report tries to explain the complexities involved in this technology in a simple but precise manner, so that all the methods implemented in it are understood by the reader at prima facie. This report, tries to compare the conventional modes of transport with maglev trains in various aspects such as safety, durability, speed, comfort and so on. Thus, providing the advantages and disadvantages of the trains. Further, this report helps us to learn about the various cities around the world, where maglev trains currently run and also provides an overview of the proposals for such trains, which are being considered as a promising investment globally. Consecutively, it deals with the accidents that have occurred at places where maglev trains have been implemented and the reasons that triggered them. This data has been included so that such incidents may be avoided in the future and in order that certain necessary modifications are made to improve the safety measures of these trains. Capable of travelling at speeds of 250 to 300 miles-per-hour or higher, maglev would offer an attractive and convenient alternative for travellers between large urban areas for trips of up to 600 miles. It would also help relieve current and projected air and highway congestion by substituting for short-haul air trips, thus releasing capacity for more efficient long-haul service at crowded airports, and by diverting a portion of highway trips. Finally, our report gives a peek into the future expansions of maglev trains and thus undoubtedly assures its readers that maglev trains are no longer a science fiction, and are in fact the future of world transportation.

Femtocell

Mobile cellular and 3G networks normally ften suffer from poor penetration and reception in certain areas, like indoors. This decreases the quality of voice and video communication and slows down high-speed services. A femtocell is a small device that is used to improve wireless coverage over a small area, mostly indoor. It is a small cellular base station, also called a wireless access point that connects to a broadband Internet connection and broadcasts it into radio waves in its area of coverage. As a result, mobile handsets can handle phone calls through the femtocell, via the broadband Internet connection. The name femtocell has the prefix 'femto', meaning a very small cell (area of network coverage). Small is rather a big word here, because femto denotes a division that is mathematically represented by 10 raised to the power of -15, or a quadrillionth. In plain English, it is one divided by a figure with fifteen zeros. Well, close to infinitely small. The first interest in femto cells started around 2002 when a group of engineers at Motorola were investigating possible new applications and methodologies that could be used with mobile communications. Further after 2yrs. In 2004 more attention was given to this technology and it was enhanced further. A femtocell is a small device that is used to improve wireless coverage over a small area, mostly indoor.
Third-generation cellular technology suffers from inadequate indoor-signal penetration, leading to poor coverage in the environment where consumers spend two-thirds of their time. Poor coverage diminishes the quality of voice and video applications, and slows down high-speed data services To keep customers satisfied, 3G carriers have increased capacity by building additional microcell sites. This strategy is becoming much less attractive. Site acquisition costs are exorbitant and continue to mount as space on viable towers and buildings fills up, landlords exact high rents and regulators impose onerous permit requirements. Public opposition to the building of large-scale base stations is increasingly common.

Problem-3G Coverage Issues

• 3G cells are smaller by virtue of supporting higher data rates
• 3G infrastructure needs to Proliferate
• Femtocells are a vehicle for expanding 3G coverage and improving indoor coverage
• Infrastructure must evolve to support millions of small cells
Third-generation cellular technology suffers from inadequate indoor-signal penetration, leading to poor coverage in the environment where consumers spend two-thirds of their time. Poor coverage diminishes the quality of voice and video applications, and slows down high-speed data services To keep customers satisfied, 3G carriers have increased capacity by building additional microcell sites. This strategy is becoming much less attractive. Site acquisition costs are exorbitant and continue to mount as space on viable towers and buildings fills up, landlords exact high rents and regulators impose onerous permit requirements. Public opposition to the building of large-scale base stations is increasingly common. Acquiring a site is only half the battle: Sophisticated base station equipment must then be purchased, installed, insured, operated and maintained. The net present value of a cell site in the U.K. is estimated to be $500,000. Carriers thus face a serious dilemma.
Well it's clear more and more consumers want to use mobile phones in the home, even when there’s a fixed line available. Friends and family usually call a mobile number first, and it’s where messages and contact lists are stored. However, it is often the case that providing full or even adequate mobile residential coverage is a significant challenge for operators. From a competitive perspective, femtocells are important because mobile operators need to seize residential minutes from fixed providers, and respond to emerging VoIP and WiFi offerings. Improving user experience in the home is also essential for reducing churn and gaining marketshare and new revenues. However, high deployment costs ensure that 3G networks rarely extend beyond the regulatory minimum.
Using femtocells solves these problems with a device that employs power and backhaul via the user’s existing resources. It also enables capacity equivalent to a full 3G network sector at very low transmit powers, dramatically increasing battery life of existing phones, without needing to introduce WiFi enabled handsets.
• Indoor cellular coverage
• Can “talk” with any handset device • Low cost backhauling
• More than 50% voice calls and more than 70% data traffic are originated indoor
• The 3Cs--coverage, churn and capacity--are stifling 3G adoption.
• Femtocells produce cost savings as well for the carriers. Consumer's home in essence becomes a cell site and there is no site acquisition costs involved.
• Electricity bills can be minimized.
• Unlimited mobile minutes for a fixed monthly fee.

Why Femtocell?

The 3Cs--coverage, churn and capacity--are stifling 3G adoption. Femtocells produce cost savings as well for the carriers. Consumer's home in essence becomes a cell site and there is no site acquisition costs involved. Electricity bills can be minimized. Unlimited mobile minutes for a fixed monthly fee. The call charges can also be reduced based on which subscriber we are using. Provides better coverage and also prolonged battery life compared to others. Portable and easy to install and use.

Concept of Femtocell

• Indoor cellular coverage

• Can “talk” with any device

• Low cost backhauling  

Working of Femtocell

Femtocells from part of the mobile operation’s network, although they are located at home or in the business. Most of the functionality of a completer 3G cell site has been miniaturized onto a chip, which look and operates like a WiFi access point, and is connected via broadband DSL back to the mobile operator’s network. A femtocell is installed at home and connected to mains power and a standard broadband IP connection (typically DSL) through to the mobile operator’s core network. Voice calls, text massages and data services are provided by the same systems. Femtocells operate at very low radiation power levels (50 milliwatts peak output during a call, much lower when idle), and typically have a range of 200 meters.
The signals do not travel through walls particularly well, but this is a benefit because it allows the frequency to be reused for other calls in nearby building. Where users walk outside or out of range, calls are automatically handed over to the external mobile network. Any standard 3G phone can be used on the femtocell if permitted by the mobile operator. Unlike WiFi access points, 3G Femotcells operate using licensed spectrum and thus must be supplied and operated in conjunction with the mobile operator Figure 1 shows working of femtocell. The battle is most likely to be between the modified 3G RAN (which some RAN Network vendors are keen to promote because it reuses their existing RNC products) versus UMA, which has new, custom designed systems architected to handle the much larger number of cells and IP connectivity.
SIP based solutions may be of interest where the user wants to bypass the network operator When registered handsets enter the range of a femtocell, handing over to the femtocell network is done automatically, such that calls are channeled through the broadband connection. One femtocell can support up to 5 mobile handsets. Femtocell technology, which is another block in the Fixed-Mobile Convergence concept, is still in its early days and it is receiving fierce competition from UMA and Wi-Fi technologies. For instance, one might ask why invest in femtocells when a cheap Wi-Fi router can do the work with a Wi-Fi supporting handset, given that handsets supporting Wi-Fi are becoming more common and are being shipped by hundreds of millions.

Advantages

• A Femtocell is used for compensating poor cellular coverage inside the homes – in some places.
• A Femtocell can also give lower call charges while the caller calling from home, using the Femtocell as it directly connects to the core network through the internet.
• Some vendors are also planning to incorporate all the three features – Wi-Fi, cellular and DSL into the same box to achieve maximum functionality.
• The voice calls/data calls through the Femtocells are encrypted and the cell phones automatically switches over to the Femtocells when they come in their range – eg. in homes, where they are installed.
• Femtocell units can handle up to three or four simultaneous calls, from the same operator, depending on the model. They can operate with normal cellphones, without any enhancements.
• Femtocell units can help related cellular services like 3G by offering a better speed and data rate when inside buildings, where the coverage and data rate is generally lesser than outside.
• Generally, the cell towers are back-hauled by using lines with bandwidth of around 2 Mbps (in some places) and hence when newer services like 3G are introduced, these lines may not be sufficient and hence may require a upgrade. But with Femtocells, since the subscribers internet connection is used, there may not be an issue with existing infrastructure if Femtocells are adopted in a large scale.
• Femtocells can not only extend the cellular macro network but can also become the primary network if enough Femtocells are adopted in an area. So, all future upgrades etc. can be done by the Femtocells itself, reducing the number of macro base stations required to cover an area – but this is a long shot, based on the current situation and the problems described below.

Computer: Gi-Fi

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Abstract:

Gi-Fi will helps to push wireless communications to faster drive. For many years cables ruled the world. Optical fibers played a dominant role for its higher bit rates and faster transmission. But the installation of cables caused a greater difficulty and thus led to wireless access. The foremost of this is Bluetooth which can cover 9-10mts. Wi-Fi followed it having coverage area of 91mts. No doubt, introduction of Wi-Fi wireless networks has proved a revolutionary solution to “last mile” problem.However, the standard's original limitations for data exchange rate and range, number of channels, high cost of the infrastructure have not yet made it possible for Wi-Fi to become a total threat to cellular networks on the one hand, and hard-wire networks, on the other. But the mans continuous quest for even better technology despite the substantial advantages of present technologies led to the introduction of new, more up-to-date standards for data exchange rate i.e., Gi-Fi.

Gi-Fi or Gigabit Wireless is the world's first transceiver integrated on a single chip that operates at 60GHz on the CMOS process. It will allow wireless transfer of audio and video data up to 5 gigabits per second, ten times the current maximum wireless transfer rate,at one-tenth of the cost,usually within a range of 10 meters.It utilizes a 5mm square chip and a 1mm wide antenna burning less than 2 watts of power to transmit data wirelessly over short distances, much like Bluetooth.

The development will enable the truly wireless office and home of the future. As the integrated transceiver is extremely small, it can be embedded into devices. The breakthrough will mean the networking of office and home equipment without wires will finally become a reality.

There are many usage cenarios that can be addressed by Gi-Fi. The following are some mobility usage applications of Gi-Fi.