DRY WALL CONCEPT

                             

                   Hello friends you have heard about walls , paintings, finishings. Have you ever heard about dry wall finishing ?  Here I’m going to present a simple overview about dry wall finishing  in this article. I’m not going  to introduce more technical terms to make you bore of reading.   

What is Drywall?

                 Drywall is a modern construction product ,namely  a wide flat board used to cover walls or partitions. It is made from plaster or wood pulp or other materials and used primarily to form the interior wall finishing of houses. Simply it is a interior covering material. In technical words, Drywalls are sheets or panels created by the pressing of gypsum plaster material between fiberglass or paper sheets.

                  Before the invention of drywall in the early 20th century, plaster and lath was the material of choice for finishing interior walls which is laborious and time consuming job. But when this miracle material drywall came along, builders could finish walls very quickly, without waiting for plasterers to do their job, and especially without waiting for the plaster to dry. Drywall gives you a smoother, cleaner surface, and it is much easier for the homeowner to install. It's also used to create many design features, including eaves, arches and other architectural specialties. It's quick and easy to install, incredibly durable, and requires only simple repairs when damaged. 

Some common names of this product include:

·         Dry wall

·         Sheet Rock

·         Gyp board

·         Gypsum board

·         Wall board

·         Plaster board

                   One of the main aspects of drywall that you should be aware of are the tapered edges. Even though you may not notice it at first, the long edges of drywall are slightly tapered so that when two sections of drywall are joined (tapered end to tapered end), it will create a slight break so that drywall tape and drywall mud, otherwise known as joint compound, can be filled into that space. That way, no joints are visible.

How it is made?

                                The primary component of drywall is the mineral gypsum. It is a light-density rock found in plentiful deposits worldwide. Each molecule of gypsum (or dihydrous calcium sulfate) is composed of two molecules of water (H 2 0) and one of calcium sulfate (CaSO 4 ). Because the water present in gypsum is in crystalline form, the material is dry. In its pure form, gypsum is white, but impurities often give it colors like gray, brown, pink, or black. Gypsum that has been crushed and heated to remove 75% of its water content is known as plaster of Paris. When water is added to this fine white powder, the resulting material is easily molded into any desired shape. Besides the newly mined material, up to 20% of the gypsum used to manufacture drywall can be recycled from waste generated at the manufacturing plant or at construction sites. Gypsum produced as a byproduct of the flue-gas desulfurization process at electric power plants provides an economical, environmentally sound raw material for making high-quality gypsum board.

       

Figure shows the manufacture of dry wall

                               Two types of paper are used in the production of most drywall, and both types are made from recycled newspaper. The ivory manila face paper, when properly primed, readily accepts most paints and other types of wall finishing products. The gray back paper can be laminated with aluminum foil to produce a special type of drywall that resists the flow of water vapor in environments like bathrooms. Fabrication of drywall consists of placing the gypsum core material between two layers of paper, drying the product, and finishing it into panels of standard size.

Why Drywall preferrable?

                                                  

                       This title gives you an idea of why drywall is preferable to wet plastering. Over the years, plaster has constituted primarily clay, gypsum coating, lime renders, cement and even Artex. There are a few problems with wet plastering though and this is related to its application. Wet plastering can only be done by a skilled plastered. Once the plastering has been done, it has to dry out. Many a times, after drying up, it has shown movement cracks and not to mention there is the problem of shrinkage as well. Apart from this, if wet plastering has not been done by a skilled plasterer then the finish will be bad and it will not be durable.

                       Due to the disadvantages of using wet plastering, more and more people have started to use plaster board in their homes and this phenomenon has risen only in the last 30 years. Today there is an ever increasing popularity for using plasterboard for walls as it can be put up quickly and can be easily finished using sandpaper, tape, and paint.

Drywall Thickness Requirements :

                              One of the most important properties of drywall is its resistance to fire due to the layer of gypsum that it has in between its sheets. This fire resistance offered by drywalls has a relation with the thickness of the installed drywall material. It is essential that one knows about standard drywall thickness and sizes when going for an installation. Although drywall thickness can vary over a range of sizes, the highly preferred thickness sizes are:

• 5/8 inch (1.59 cm)
• 1/2 inch (1.27 cm)
• 1/4 inch (0.635 cm)
• 3/8 inch (0.952 cm)              

Fire resistance property of Drywall :

                   Surfaces, walls and ceilings can become virtual death traps if they don't inherently possess fire resistance qualities. We already have cited above that gypsum in its natural state contains the water in crystalline form bound in the form of hydrates. When exposed to heat or fire, this water is vapourised, retarding heat transfer. Therefore, a fire in one room that is separated from an adjacent room by a fire-resistance rated drywall assembly will not cause this adjacent room to get any warmer than the boiling point (100°C) until the water in the gypsum is gone.

Benefits of Drywall :

·         Fire resistant

·         Can be recycled and reused

·         Resists fracturing

·         Makes home quietier because gypsum naturally resists sound transmission

Drywall with interior finishing :

        The figure given below shows dry wall with interior finishing.

By
MANOJ , III year civil
Anna univ.tech
Mail : mano.nitharson@gmail.com     

Follow on : http://twitter.com/manonitharson

ROBOTS To inspect the transmission Line:

ROBO INSPECTION IN TRANSMISSION LINE...

Times sure have changed. robots used to be the only effective way to

inspect an overhead transmission line was by flying around in a helicopter with a pair of binoculars. But using choppers isn’t cheap when you’ve got thousands of kilometres of high-voltage equipment to watch. Faced with tight budgets and an aging workforce, utilities are increasingly experimenting with line-crawling robots as a safer, less expensive way to inspect their transmissioninfrastructure, much of it installed during the 1970s and showing its age. “There have been accidents over the years of people flying in helicopters, so the first issue here is safety,” says Andrew Phillips, director of power transmission studies at the Electric Power Research Institute. Phillips says the average industry worker’s age is 48 and many of the most skilled linemen are nearing retirement. “We just don’t have those people anymore.” He adds that robot line inspectors will help bridge the coming skills gap, improve worker safety and be less costly in the long run compared with conventional approaches to line inspection. “The expectation is that it will be at least less than 70 per cent of the cost.” It’s a trend that Hydro One — which has about 29,000 circuit kilometres of high-voltage transmission lines to monitor throughout Ontario — is closely following. “We’re definitely tracking the progress,” says George Juhn, director of investment planning and asset managing at the utility. “It looks like the future . . . but we’re not there yet.” Québec-Hydro is being proactive. It began researching robotic inspection devices after the 1998 ice storm, in which rain froze on transmission lines, adding weight that led to the collapse of lines and towers, leaving more than 4 million people in Quebec, Ontario and New Brunswick without electricity – many for several weeks. So the utility developed a small, remotely controlled robot called LineRover and in 2000 began using it as a way to de-ice live transmission wires. It worked well, and the LineRover evolved as more sensors and cameras were added, allowing it to perform more detailed inspections as well as spot trees and other vegetation that could short out lines. It was an overgrown tree, for example, that triggered the massive Northeast Blackout of 2003. “But the LineRover can’t cross obstacles,” says Montambault, referring to the robots’ inability to move past transmission towers and hop on and off different lines. So he and his research team developed a more advanced model, called LineScout, which has been used by Hydro-Québec since 2006 and B.C. Hydro since 2008. The battery-powered LineScout is waterproof, equipped with four cameras, packed with sensors that can detect problems such as corrosion, and capable of working in extreme temperatures. It hangs from the line like a mechanical sloth on roller skates, travelling at about four kilometres an hour. Each battery charge allows it to perform six or seven hours of work. “The main challenge was to develop this robotic platform to be reliable, cross obstacles and really reach almost any place on our circuit in harsh environments,” says Montambault. He said it used to be that lines were de-energized —disconnected temporarily from the grid – so workers could inspect them safely. But rising demand for electricity is making it more difficult to take lines out of service, requiring that work be done on live wires. “Now they can send the robot to do the live-line inspection, bring back high-quality images and data, then let an engineer on the ground decide if repairs are necessary,” he says. over at the Electric Power Research Institute, efforts are being made to develop an even more sophisticated robot, one that can be put up on a line and left alone for long periods with little human intervention.

Such a device would be autonomous and capable of charging itself, likely by harnessing ambient energy from the transmission lines themselves. The institute has already developed a 64-kilogram, two-metre prototype that is being tested for the first time at an outdoor lab. It is equipped with solar cells that provide a small amount of backup emergency power, can hunt for connections that may be faulty as a result of overheating and can detect electromagnetic noises in equipment that could suggest problems. All the data that’s collected, including high-quality digital images, can be transmitted in populated areas through cellphone signals or, in more remote areas, via satellite link to a central office. Robots that not only inspect but also repair faulty lines are also a  “That would be the beginning of what we call intervention or manipulation tasks,” Montambault says. “It’s a challenge, because the robot has to be stable, precise and have enough dexterity.” It’s an area where we can shine, he adds dproudly. “Canada is truly a leader in this.”

FAN With out blade !!!

Dyson.the name that has always been associated with vacuum cleaners, now have come up with a revolutionized table fan that comes with no blades and friendly to the fingers of children.

The Dyson bladeless fan is called Air Multiplier which takes table fan to a new level, able to keep you cool even it has no blades. How does it do that?

WORKING: Actually the Air Multiplier has blades in it, but they are hidden inside the lower canister. Dyson simply borrows the same concept of how a vacuum cleaner is setup to make this bladeless fan. The hidden blades produce air which will then get re-routed through the ring, which sounds like an amplifier for the air.Since the Air Multiplier fan comes with no blades, it’s definitely one that families with kids should own which it can be much safer to the fingers of your kids. And some more it should produce less noise as no air-chopping.

COST:

Dyson is asking for $300 for the 10-inch model of the Air Multiplier, and a 12-inch model costs $329.99. These are all you have to pay to ensure your kids’ fingers intact.

Kiwi device to make broadband Internet 50 times faster at no extra cost .

                                     A company in New Zealand has created a device that promises to increase the speed of broadband Internet by 50 times. Manufacture by Remote Management Systems, the system looks like a modem, and connects with homes' existing wiring to boost broadband speeds without having to pay the more than 800 dollar fee for re-wiring a home with fibre-optic cables to get such fast internet.
It's called a service delivery point and has been designed by operations manager Alan Jacks, production design engineer Hayden Short, and development engineer Chris Johnston.
          Telecom's infrastructure division, Chorus, has already taken orders for the product. The company is also marketing to Australia, and has received interest from Britain, Singapore, Taiwan and France.
An additional advantage to those who already have fibre optic cabling and still wish to use the device - it will act as a backup electricity system.
The firm is also in discussions with banks and government departments to keep eftpos machines, security cameras operating and alarms running.
"This is going to make us big," Stuff.co.nz quoted Feygan as saying.

"We have invested millions of investors' money, worked weekends and long hours and it's finally paying off," he added.

Development of Wireless Power Transmission System by MURATA

Following the foot step of Sony’s and like, Murata Manufacturing has made an announcement on development of a wireless power transfer technology ,namely field-coupled wireless power transmission system capable of supplying power to devices wirelessly, where the devices can be charged by simply placing them on the charger without any needs for power cords or other physical connections.


The filed-coupled system is a wireless power transmission method, where the electrodes are positioned at the power-sending and power-receiving ends, where the energy can be transmitted through the electric filed that has been generated between these electrodes. Due to the fact that capacitance is generated between two electrodes, the system is also called a capacitance coupling system. The system has been developed based on Murata’s circuit design know how and the power transmission technology of TMMS. The new system can be targeted for various applications such as charging of cell phones, mobile music players, digital still cameras, notebook PCs, light fixtures, decorations, etc. Also by incorporating the new charger into an office desk, the desk will turn into a “smart” desk capable of charging notebook PCs, and other such devices. That’s not all, by incorporating the system throughout transportation and accommodation facilities, devices can be charged anywhere without any needs for AC adaptors. The new system comes with transmitted power of 1 to 10 W. Murata is planning a mass production by 2011, with a monthly production of 10,000 units. The target price for pair power-sending and receiving module is 980 JPY. There are 10 patents pending relating to this transmission method.