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Advantages and disadvantages of solar energy

There are many advantages and disadvantages of solar energy in 2012.  Electric power is getting much more expensive with the increase in the cost of fossil fuel. Most people’s electric bills are increasing by at least 6% per year.
Solar panels can be situated almost anywhere there is direct sunlight available. They can be placed on the roof of a house or in an open unused area, as long as they can come in contact with direct sunlight. If you offset a majority of your electric usage with solar, you end up paying at a lower tier level. Therefore, what electricity you do use, is at the lowest price.

Advantages of solar energy

·      A solar system will actually increase the value of your home.
·     Solar energy can be a very efficient source of energy in a very large area of our planet. On overcast days, there can still be production with some of the newer technologies that are in existence.

·    It is very costly to lay new high voltage lines across new territory, where solar panels can be placed in any remote location at a fraction of the cost.

·   There is no pollution put into the atmosphere from solar panels.

·     Although the initial investment on solar is fairly high, there is very little upkeep expense.

·     Another great pro for solar energy is the ability to gather from the largest energy source available, the sun from the most remote areas of the planet, many of which are not even linked to a national grid system. Even in space, solar panels can be utilized to gather energy to power spacecraft.

·    Solar can be installed on top of residential roofs or above parking structures, eliminating the problem of finding the required space for solar panels.

·     The warranty on most solar panels is 20 years or more. The solar inverters are typically guaranteed for at least 10 years.

·      Solar reduces the use of fossil fuel and our dependency on it. Solar is truly a green source of energy.

·     There is no noise pollution generated during solar production. It is the quietest way to produce energy. The use of fossil and even other renewable fuels, such as wind and hydro production can be very noisy.

Disadvantages of Solar Energy:

·      The biggest con of solar power is the cost of solar panels. The initial cost, or start-up expense, is pretty high.

·    Solar can only be produced during daylight hours. Therefore, for 50% or more of the time, your system isn’t producing any power.

·     Cloudiness or anything that blocks the sun from hitting the solar device can affect the efficiency of the system.

·    The more pollution or dust that gets on a solar panel, the less productive it will be. Solar panels need to be cleaned off periodically to keep a system at its maximum efficiency.

·      Some areas of the planet aren’t as conducive to sunny weather. The more rainy an area is, the less solar production you can have.

Positioning your solar device

Which direction should my solar device face?

Regardless of where you are on the planet and regardless of the time of year, the sun will of course always rise in the east and set in the west. As we in Egypt are in the northern hemisphere therefore, and the sun is above the equator, your solar panels will work best if they are south facing. This is because they will be facing the sun all day long. North facing panels will be facing away from the sun and will be inefficient.

What is the best angle for my solar device?

Whilst everyone can easily agree upon the optimum direction for solar panels, the question of angle of tilt is less straightforward. On the equator it is simple – horizontal is best as the sun will be directly above. At the poles the sun will always be near to the horizon so vertical is best. At other latitudes, such as Egypt, the sun will appear at a different angle relative to the Earth at different times of year (i.e. it will be lower in the sky in winter and higher in summer).
This means that if you point your device at where the sun will be at midday on the summer solstice (midsummer) then you may maximize summer efficiency but you’ll lose out in winter when your array will be pointing “over” the sun.

For the Northern hemisphere, your device should be facing as close to south as possible.
In the Southern hemisphere, you want to orientate your solar device to the North.

The best angle for your solar panels to be at is the angle of your latitude.
You can also set your solar device for optimum performance in summer and winter. In summertime, the solar panel should be at a lower angle. This is because the sun is higher over head.
In wintertime, the sun moves across the sky at a lower angle. So by angling your solar panels higher, you will catch more sun rays.

If you plan to adjust your solar array tilt angle seasonally, a good rule of thumb is:

Keeping your solar panels out of the Shade

Shade is the thing that will have the biggest negative effect on the efficiency of solar device, and it can even cause damage. Before deciding how to position them therefore you should assess the area to see whether there are any surrounding structures or trees as well as moving throughout the day, shadows will be in different positions throughout the year due to changes in the angle of the sun, so if you are in doubt you may need to make an assessment over a six month period in order to see the full range of shadows. You’ll also need to check at different times of the day.
There are computer models available that will give a virtual picture, which would avoid the need to measure over an extended period.

Solar tracking devices

The best way to ensure that you get maximum efficiency from your solar panels is to use a solar tracking device. A dual axis system (one that tracks the sun across the sky and adjust the angle of the panels according to the height of the sun in the sky) could increase efficiency by 30% – 40%. Such systems are expensive however and it may be more cost effective to either purchase additional panels or simply accept the lesser efficiency of a fixed array.
As well as the initial expense, solar tracking devices tend to need more maintenance than fixed arrays because they have more moving parts.

Why solar?

Our energy
In everyday life, we consume a tremendous amount of energy.
Our lives are styled around consumption—consumption of natural resources
and consumption of energy.
Figure 1 dramatically illustrates where all of this energy goes.
These figures are for a U.K. lifestyle, but we can take this as being representative for people who live in the “developed world.”
The bulk of our energy consumption goes on space heating—58%—this is something that can easily be provided for with passive solar design. Next is water heating, which requires 24% of the energy which we use—again, we can easily heat water with solar energy. So already we can meet 82% of our energy needs with solar technologies! The next 13% of our energy is used to provide electrical power for our lights and home. we can produce clean electricity from solar energy by photovoltaics . with no carbon emissions. The remaining 5% is all used for cooking— again it is easy to cook with the power of the sun! So we have seen that all of our energy needs can be met with solar technologies.

Why solar?
The short answer to this question is “Why not solar?”
Solar energy is clean, green, free, and best of all, isn’t going to be
going anywhere for about the next five billion years.
If we look at Figure 2 , we can see that there is a real solar energy
resource and there is enough solar energy to be economically exploited.

Again I repeat

Transducer

A transducer is an electronic device that converts energy from one form to another. Common examples include microphones, loudspeakers, thermometers, position and pressure sensors, and antenna. Although not generally thought of as transducers, photocells, LEDs (light-emitting diodes), and even common light bulbs are transducers.

Transducers can be classified to two categories :

1- Input Transducers
Input Transducers convert a quantity to an electrical signal (voltage) or to resistance (which can be converted to voltage). Input transducers are also called sensors. Examples:

• LDR converts brightness (of light) to resistance.
• Thermistor converts temperature to resistance.
• Microphone converts sound to voltage.
• Variable resistor converts position (angle) to resistance.

2- Output Transducers
Output Transducers convert an electrical signal to another quantity.
Examples:

• Lamp converts electricity to light.
• LED converts electricity to light.
• Loudspeaker converts electricity to sound.
• Motor converts electricity to motion.
• Heater converts electricity to heat.

DC Motors

Recently I was working in a Solar Car design .

I had a problem in the designing of this solar car As my study is mechanical Engineering .

The problem was that the solar cells produce ( Direct current ) while all the motors i deal with work with ( Alternating current ) .This is related to ( Electrical Engineering Field )

After long day of search  I found this file talking about motors work with Direct Current ( DC Motors ) 

I hope that i can help somebody faced the same problem . ^_^

HERE YOU ARE THE LINK AGAIN http://www.4shared.com/get/c7Q1RV20/Lecture_09_DC_Motor.html

future with robots

Till now designers are unable to make a robot that can simulate the smooth movement of human ,but robot also has some features .Robot can work long time without rest or mistakes, can carry heavy things and can work in narrow space such as in nanotechnology. Now we are going to discuss the latest Developments of robots in some important fields in our everyday life .

Using Robots to Build Beautiful Structures

We will let the photos talk about how we can use robots to build fantastic structures :

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Home-robots :

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t's been a long time coming, but Intuitive Automata's Autom robotic weight loss coach is now up for pre-order on a dedicated "MyAutom" website. If you haven't been following the saga of Autom, it was first an MIT Media Lab robot with a significantly different look. Autom's developer at MIT, Cory Kidd, co-founded Intuitive Automata to help commercialize Autom based on the original MIT project, and it's starting to look like everything will be coming together within the next year. Not to get off topic or anything, but it's fantastic to see a research robot like this make the difficult jump into the consumer market. Congrats to Dr. Kidd!

Anyhow, back to the robot. We know that Autom is designed to be exceptionally interactive, crunching data on your health, diet, and exercise regimen and giving back friendly and constructive criticism. Studies have shown that people who use Autom stick with their diet and exercise routines for twice as long as people using more traditional weight loss methods. Don't ask me how, maybe it's something about those big blue eyes?

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If this sounds good to you, you can be one of the very first people to have this friendly little robot helping you out every day with a deposit of $195. This is not the final price, however, it's just the pre-order deposit. The final price is the $195 deposit plus a balance of $670 when the robot ships, for a total of $865. This does seem a bit steep, although I'll admit to not being familiar with how much a typical weight loss program costs.

military-robots:

Textron's T-Ram is the Suicidal Mini-UAV You've Always Wanted

The U.S. Air Force has been looking for what they're calling a "Lethal Miniature Aerial Munition System" to be fielded with special ops units next year. If the name of the program doesn't explain it, the above pic should: they essentially want a mortar round with wings, a camera, and a little engine. In other words, a surveillance UAV that can suicidally attack targets on command.

There are several systems with this capability currently in the works, but the operational requirements and principles are all the same. LMAMS needs to weigh three kilos or less, including the vehicle and the launching system. It needs to be able to deploy and fire in under 30 seconds, reach an altitude of 100 meters, and acquire and track a human-sized target in a further 20 seconds. At that point, the drone can either dive at its target, landing within a one meter radius and exploding its small (but still quite lethal) warhead, or it can loiter for up to 30 minutes, sending back live video.

Now, this seems like a fairly dangerous little robot to have around, but before you get all worked up about killer robots and stuff, remember that these special ops units already have tools to deal with situations that the LMAMS is designed for: namely, blindly chucking dumb mortars and grenades at things, calling in air support, or putting themselves in harms way to get a better view of their target. All the LMAMS does is to reduce risk and collateral damage. Or at least, that's the idea, but whether it'll work in practice remains to be seen.

humanoids :

Dr. James Law, a researcher at the Department of Computer Science at Aberystwyth University, has had an absolutely fantastic idea: he's nominated the iCub robot to carry the Olympic Torch as part of the 2012 Olympic Games, which will be held in London (that's in England, folks) starting next summer.

Dr. Law is proposing that iCub be included in the torch-carrying relay in honor of the 100th anniversary of the birth of Alan Turing, one of the guys who arguably invented the computer and whose test for artificial intelligence robots are continually striving to pass. This is a great idea, but I think that iCub should be part of the torch relay on its own merits: it'll be a first for robots and great publicity for engineering education and all that. Or at least, it'll be great as long as iCub doesn't faceplant in a puddle and snuff the torch out.

The only problem with this idea is that the short-sighted and obviously outdated nomination rules specify that all nominees have to be at least 12 years of age, which would mean that iCub wouldn't technically qualify. On the upside, nowhere does it say that nominess have to be human, so maybe iCub has a shot at this after all.

Smallest electric motor ever

For the first time, an electric motor has been made from a single molecule. At 1 nanometre long, that makes the organic compound the smallest electric motor ever.
Its creators plan to submit their design to Guinness World Records, but the teeny motor could also have practical applications, such as pushing fluid through narrow pipes in "lab-on-a-chip" devices.
Molecules have previously converted energy from light and chemical reactions into directed motion like rolling or flapping. Electricity has also set an oxygen molecule spinning randomly. But controlled, electrically-driven motion – necessary for a device to be classed as a motor – had not yet been observed in a single molecule.
To address this, E. Charles Sykes at Tufts University in Boston and colleagues turned to asymmetric butyl methyl sulphide, a sulphur atom with a chain of four carbons on one side and a lone carbon atom on the other. They anchored the molecule to a copper surface via the sulphur atom, producing a lopsided, horizontal "propeller" that is free to rotate about the vertical copper-sulphur bond

Record smashed

Above the molecule they placed a metal needle a few atoms wide at its tip. When they flowed a current from this tip, through the molecule, to the conductive copper below, the molecule converted the electrical energy into rotational energy. It bounced around in jittery hops about 50 times a second.

Because the propeller is asymmetrical, there are two ways it can be oriented with respect to the copper. In one orientation – but not the other – the molecule's hops were not random but slightly biased towards rotating clockwise, allowing the researchers to classify it as a motor.

It is not clear why the bias occurs but Sykes suspects that an inherent asymmetry in the tip of the metal needle could explain why it only occurs in one molecular orientation.

Friction fighter

If accepted by Guinness, the motor will be a record smasher. The current world-record holder for the smallest electric motor is a giant by comparison, composed of two 200-nanometre-long carbon nanotubes. Current running through these nanotubes pushes drops of molten metal from the outside of one tube to the other.

Sykes hopes to harness his tiny motor to fight the friction that slows fluid flow in nanosized tubes.

Kevin Kelly of Rice University in Houston, Texas, who was not involved in the work, points out that if electrical energy transfer behaves differently depending on the shape of the molecules, this could have implications for the design of molecule-scale electrical circuits, which could be used in tiny sensors or computer chips.

Journal reference: Nature Nanotechnology, DOI:

Fuel Cells ( Energy Source of the Future )

According to many experts, we may soon find ourselves using fuel cells to generate electrical power for all sorts of devices we use every day. A fuel cell is a device that uses a source of fuel, such as hydrogen, and an oxidant to create electricity from an electrochemical process.

Much like the batteries that are found under the hoods of automobiles or in flashlights, a fuel cell converts chemical energy to electrical energy.

All fuel cells have the same basic configuration; an electrolyte and two electrodes. But there are different types of fuel cells, based mainly on what kind of electrolyte they use.

Many combinations of fuel and oxidant are also possible. The fuel could be diesel or methanol, while air, chlorine, or chlorine dioxide may serve as oxidants. Most fuel cells in use today, however, use hydrogen and oxygen as the chemicals.

Fuel cells have three main applications: transportation, portable uses, and stationary installations.

In the future, fuel cells could power our cars, with hydrogen replacing the petroleum fuel that is used in most vehicles today. Many vehicle manufacturers are actively researching and developing transportation fuel cell technologies.

Stationary fuel cells are the largest, most powerful fuel cells. They are designed to provide a clean, reliable source of on-site power to hospitals, banks, airports, military bases, schools, and homes.

Fuel cells can power almost any portable device or machine that uses batteries. Unlike a typical battery, which eventually goes dead, a fuel cell continues to produce energy as long as fuel and oxidant are supplied. Laptop computers, cellular phones, video recorders, and hearing aids could be powered by portable fuel cells.

Fuel cells have strong benefits over conventional combustion-based technologies currently used in many power plants and cars. They produce much smaller quantities of greenhouse gases and none of the air pollutants that create smog and cause health problems. If pure hydrogen is used as a fuel, fuel cells emit only heat and water as a byproduct. Hydrogen-powered fuel cells are also far more energy efficient than traditional combustion technologies.

The biggest hurdle for fuel cells today is cost. Fuel cells cannot yet compete economically with more traditional energy technologies, though rapid technical advances are being made. Although hydrogen is the most abundant element in the universe, it is difficult to store and distribute. Canisters of pure hydrogen are readily available from hydrogen producers, but as of now, you can't just fill up with hydrogen at a local gas station.

Many people do have access to natural gas or propane tanks at their houses, however, so it is likely that these fuels will be used to power future home fuel cells. Methanol, a liquid fuel, is easily transportable, like gasoline, and could be used in automobile fuel cells. However, also like gasoline, methanol produces polluting carbon dioxide.

Get more information here .. http://ze-engineer.blogspot.com/2011/02/dont-know-about-fuel-cell-technology.html

The 15 most significant cars of the 2011 Frankfurt motor show

Over 100 new cars were unveiled at the 2011 Frankfurt motor show, but which are the most important? From production cars to concepts that will never be built, CAR's road test editor Ben Pulman, decides on the 15 most significant models premiered at the IAA...

1 – Land Rover DC100 concept

Chunky and funky, it’s Land Rover’s Evoque, the Defender urbanised, modernised and stylised for the 21st century. Range Rovers have become too ‘bling’, but the DC100 has the restrained elegance of the Disco 3 – we’ll ignore its bright yellow sister, the speedster-style DC100 Sport. It’s not a conventional, utilitarian take on the Defender for the traditional Landie customer, but bar the Army just how much of a market is there out there? The most profitable sales are to be found in market segments where you can charge premium prices, so don’t expect a wash-with-a-hose £15k rival for the Panda 4x4. Most importantly, the DC100 – and its Sport sister – confirm that Land Rover will replace the Defender (it’s about time really), and public reaction to these two will shape the new car due in 2015.

2 – Mercedes F125 concept

Not the best-looking Merc concept car of recent years, but ignore it at your peril. Mercedes’ F-branded concepts always offer a glimpse of the future before any other manufacturer, and the F125 (built to celebrate the company’s 125th anniversary) is more forward gazing than most – think two generations hence. The F125 boasts a hydrogen fuel cell, cutting edge lithium-sulphur batteries, a gargantuan 620-mile range, an eMatic all-wheel drive system, and a lightweight body built from the ground up to accommodate the specific requirements of a hydrogen-fuelled powertrain. It’s Mercedes going all-in on an H2 future.

3 – Volkswagen Up

It’s not an innovative rear-engined and rear-wheel drive supermini like the original concepts promised; in fact, looking at its conventional layout you’d be forgiven for just thinking it’s VW’s replacement for the Fox. Which it is. But the VW Group has put a lot of thought (and thus money) into this car, there’ll be Skoda and Seat versions too, and a gaggle of Up concepts at Frankfurt previewed potential GTI, EV and faux-4x4 versions. Hundreds of thousands of these things will be built, and with that badge to boot, Ford’s Ka and every other little city car out there should be worried. Simple, straightforward, and destined to be a success.

4 – Skoda MissionL concept

Understated and so easy to overlook – it’s just a Skoda, after all. But the MissionL – anyone else read it as Missoni? – will reach production (almost unchanged) in 2012, and it heralds Skoda’s entry into the hotly contested hatchback class, thus far ruled by the Focus and Golf. With VW parts bin backing, Skoda’s propensity to offer more space for less money, and a badge that those in the know now respect, it’s going to shake things up. And help double Skoda’s annual sales to 1.5m units by 2018.

5 – Porsche 911

No, not the new 911. We’ll admit the new 991 is significant (it’s cleaner, faster and better looking than its 997 predecessor, and will become a hybrid at some point in its life) but instead the now-defunct GT3 RS 4.0 is on my list thanks to a technicality – it made its motor show debut at Frankfurt.  It marks the end of a 911 that first ushered in water-cooled engines as the 996 in 1997, and secured Porsche’s future thanks to sharing parts with the Boxster. In final 4.0-litre guise it’s quite possibly the greatest road-legal 911 ever built, and unless Porsche’s engineers can work miracles, it’s also the end of the line for the amazing, motorsport-derived ‘Mezger’ flat six. Goodbye to a great.

6 – Jaguar C-X16 concept

Not actually as good looking in the metal as you might expect but there the disappointment ends (and it’s not exactly ugly). An aluminium chassis means it’s light, a supercharged 375bhp V6 for the R version means it’s fast, and prices from around £55k mean it’ll take on top-end Boxsters and bottom-rung 911s. It'll probably halve the number of deposits Porsche takes for the new 911 during the Frankfurt show.

7 – Citroen DS5

Utterly, utterly gorgeous. Citroen had a fleet of these, all in white with black wheels, shuttling tired hacks between the vast halls of the IAA, and they looked sleek, and low, and lovely. And no, I didn’t get a lift in one so I can’t be accused of giving PSA any preferential treatment. We get behind the wheel next month, and while I’d hate to assume the steering will be light and lifeless and ultimately the drive will disappoint, I reckon the DS5 was the best-looking new car at the IAA this year. Seriously.

8 - Maserati Kubang concept

Terrible. I know Porsche has the Cayenne and will soon have the Cajun, I know both Bentley and Lamborghini are working on SUVs, I know that this is the future as expanding, emerging markets demand these profitable cars which niche luxury manufacturers would only ignore at their peril. If you were the CEO, could you forgo a 4x4 knowing it dooms your company to build just a few thousand sports car each year? Or would you give the green light, secure Maser’s future, and set about improving the GT cars everyone loves? Exactly. That was from the head, so now from the heart. It’s ugly (every Maserati should be beautiful) and looks too much like a Mazda CX-7, and because it’s really a Grand Cherokee, a Porsche Cayenne is going to run rings around it.

9 & 10 – BMW i3 and i8

Couldn’t decide between these two carbon BMWs so they’re both in. Come 2013 the i3 will be launched in both range-extender and full EV forms, a £30k-plus supermini that’ll see just how much we’re prepared to pay for a car that’s shorter than a Fiesta. A genuinely innovative idea.

And in 2014 the £125k i8 supercar arrives. Audi has the R8 and Merc the SLS, and BMW missed the boat, yet while both rivals prepare limited-run, limited-range EV versions, the i8 will sail merrily past thanks to its three-cylinder hybrid drivetrain. It really is the supercar of the future.

11 – Ford Evos concept

Ignore the butterfly doors, don’t bother trying to find out what the powertrain is – instead, just look at the Evos. It’s not a jaw-dropper, but it heralds the start of a design language to replace the Blue Oval’s exisiting Kinetic Design. Which means the Mondeo, the Mk4 Focus, the next Fiesta, and every other Ford product over at least the next decade will be stylistically influenced by this car.

12 – Lancia Flavia Cabrio

Only Ferrari and Alfa seem to be surviving unmolested within the Fiat Group. Maserati has the Grand Cherokee-based Kubang, Fiat is flogging a Dodge Journey (thankfully not in the UK) and what’s going on between Lancia and Chrysler is utterly horrible. Us Brits get the American brand, which sells the 300C and Voyager alongside the Ypsilon and Delta, but it’s a name we don’t really care about. Pity the Italians then (and the rest of mainland Europe), as Lancia is being forced to sell the Voyager, the 300C (as the new Thema), and worst of the lot, the Flavia Cabrio. It’s just a 200 Convertible. There’ll be a business case behind it, but how low can you go? Worst car of the show. Look away if you don't want to be depressed.

13 – Alfa Romeo 4C concept

Another car that’s snuck in on a technicality: the 4C actually first appeared at the 2011 Geneva motor, but it’s been to the paintshop prior to its trip to Frankfurt, which gives us an excuse to feature it again. It’s gorgeous, stunning enough to distract you from the Flavia sitting opposite, and it’ll look like this when production starts in 2012. And it’s got the underpinnings to back up the good looks: carbonfibre platform engineered by Dallara, turbocharged 200bhp-plus 1.7, six-speed dual-clutch gearbox, rear-wheel drive, adaptive dampers. Just a few thousand will be built each year but it’s a brilliant halo car for Alfa to have as it returns to the USA.

14 – Toyota FT-86 II

Another car that we’ve seen before, but for Frankfurt it got a big rear wing and some new orange paint. Hardly significant, but this is the car that the CAR office is most excited about for 2012. Rear-wheel drive chassis, manual gearbox, 2.0-litre flat-four engine (with a turbo for the fast version). An excellent set of ingredients for a cheap sports car. Engineering partners Subaru meanwhile, are pissing around showing off boring transparent-paneled concepts and missing out on all the publicity.

15 – Vauxhall Rake concept

The VW Nils or Audi’s duo of Urban concepts could have featured here, as the automotive world readies a flurry a tiny, sub-500kg commuter vehicles. But Vauxhall’s effort, the Rake, is designed to be as cheap as possible (the suits mentioned a €12k starting price) with no carbon and just a simple steel chassis. And they say this could quite easily be in production by 2015. It also offers more weather protection than Renault’s open-air Twizy. An intriguing glimpse into our motoring tomorrows.

SOURCE : carmagazine.co.uk

Happy Engineer’s Day India

In India, Engineer's day is celebrated on September 15. This day is celebrated in the honor of Sir M. Visvesvaraya (1861-1962), who was a notable Indian engineer, scholar, statesman and the Diwan of Mysore during 1912 to 1919. Internationally recognised for his genius in harnessing water resources, he was responsible for successful design and construction of several river dams, bridges and implementing irrigation and drinking water schemes all over India.

He served as the dewan of Mysore State and was considered to be the architect of the all-round development of Karnataka.

Among his most successful projects are the design and construction of the K.R. Sagar dam and its adjoining Brindavan Gardens, turn-around of the Bhadravati Iron and Steel Works, setting up of the Mysore Sandalwood Oil Factory and the founding of the Bank of Mysore.

K.R. Sagar dam : 

 Other countries :

Engineer's Day in Argentina is celebrated on June 15

Engineer's Day in Colombia is celebrated on August 17

Engineer's Day in Iran refers to 24 February every year

Engineer's Day in Mexico is celebrated on July 1

I’ve no Idea about if other countries have an engineer’s day .. Do you have ??

YAK 42 CRASH ( Full Report )

The Yakovlev Yak-42 (NATO reporting name: Clobber) is a 100/120-seat three-engined mid-range passenger jet. It was designed as a replacement for several obsolete Aeroflot jets as a mid-range passenger jet. It was also the first airliner produced in the Soviet Union to be powered by modern high-bypass turbofan engines.

ABOUT ACCIDENT :

The Yak-42 that crashed near Yaroslavl taking 44 lives last week was in proper mechanical condition and the latest repairs were done to all requirements, the transport prosecution has ruled. Pilot error is the most likely cause of the tragic crash.

The last scheduled service of the plane was in August, during which the right engine was replaced and all other defects were reportedly eliminated. All these repairs were certified and correspond to requirements informed the transport prosecution.

The company that provided technical maintenance of the Yakovlev Yak-42 aircraft was inspected by experts from the Russian transport prosecution.

An investigation by the Interstate Aviation Committee also failed to find any irregularities in the aircraft’s condition and operation prior to the crash, a spokesperson for the regulator said on Monday.

“The preliminary analysis showed that the lifting weight was within the norm; the pre-start check of control channels by the crew revealed no errors…Flight recorders so far revealed no signs of commands which would indicate sudden failures,” the committee said.

As earlier investigation ruled out the possibility that low-quality fuel could have been a cause of the tragedy. Technical problems and pilot error were the likely reasons behind the Yakovlev Yak-42 plane crash.

While the technical problem theory appears less possible on Monday, the most likely cause of the tragedy remains pilot error.

“Pilots may not have accelerated enough and forced the engines too late. When the plane hit the homing beacon mast, there was no chance to bring the machine under control,” a source in law enforcement told Interfax new agency on Monday. “This version is seen as the most likely,” he added. Though no official comments have been released so far concerning this scenario.

The examination of the flight recorders is expected in the coming days after the tape has dried. The “black boxes” contain the recording of the tragic flight, confirmed in the Interstate Aviation Committee.

After one of the two survivors of the last Wednesday crash died in hospital from severe injuries on Monday, flight crew member Aleksandr Sizov remains the only witness. His condition is listed as serious but stable. He has been moved to the main ward.

The investigation will have a chance to obtain evidence from Sizov only after he recovers sufficiently to be able to talk. This may become crucial information for the experts investigating the plane crash.

Workers of Russia's Ministry of Emergency Situations inspecting the wreckage of the Yak-42 aircraft that crashed during take-off near the Tunoshna Airport, Yaroslavl Region. The plane was heading to Minsk with the Yaroslavl's ice hockey team Lokomotiv on board. (RIA Novosti/Grigory Sysoev)

Watch Video

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The sun

Our solar system is composed of the Sun and all things which orbit around it: the Earth, the other eight planets, asteroids, and comets.

The Sun is the most prominent feature in our solar system. It is the largest object and contains approximately 98% of the total solar system mass.
It is 92.95 × 106 miles away from us (149.6 × 106 km) away from us. (This distance varies slightly throughout the year, because the Earth's orbit is an ellipse and not a perfect circle)
To imagine the magnitude of this great distance, think that light, which travels at an amazing 299,792,458 meters per second, takes a total of 8.31 minutes to reach us. You might like to do a thought experiment at this point, and imagine yourself traveling in an airplane across America. At a speed of around 500 miles per hour, this would take you four hours. Now, if you were traveling at the speed of light, you could fly around the earth at the equator about seven and a half times in one second. Now imagine traveling at that speed for 8.31 minutes, and you quickly come to realize that it is a long way away. Not only is it a long way away, but it’s also pretty huge!

It has a diameter of 864,950 miles (1.392 million km.)
Although the sun is incredibly far away—it is also tremendously huge! This means that although you would think that relatively little solar energy reaches us; in fact, the amount of solar radiation that reaches us is equal to 10,000 times the annual global energy consumption. On average, 1,700 kWh per square meter is insolated every year.

Now doesn’t it seem a silly idea digging miles beneath the earth’s surface to extract black rock and messy black liquid to burn, when we have this amazing energy resource falling on the earth’s surface?

As the solar energy travels on its journey to the earth, approximately 19% of the energy is absorbed by the atmosphere that surrounds the earth, and then another 35% is absorbed by clouds.
Once the solar energy hits the earth, the journey doesn’t stop there as further losses are incurred in the technology that converts this solar energy to a useful form—a form that we can actually do some useful work with.

All you need to know before buying portable generator

What is the portable generator ?

A portable generator is a gas or diesel-powered device which provides temporary electrical power. The engine turns a small turbine, which in turn creates usable electricity up to a certain level of wattage. Users can plug electrical appliance or tools directly into the generator's sockets, or the portable generator can be professionally wired into the sub-panel of a home.

Many construction teams use a portable generator to power tools and lights at a remote site. Sports officials may also bring in a portable generator to aid in night play or to run an electronic timer/scoreboard. Most commonly, residents and businesses left without power after a weather event will use a portable generator to keep vital appliances operating. A portable generator usually has enough power to keep a freezer, refrigerator, television and some lights working.

How Many Watts Do you NeedUse the charts below to determine your wattage requirements for a portable generator.

Generator Manufacturers

Caterpillar is one of the largest industrial equipment and generator manufacturing companies in the world.

Cummins is a international leader in diesel engine and power generateration equipment.

Detroit Diesel is a manufacturer of heavy-duty diesel engines for commercial trucks and diesel generators.

Generac produces industrial, commercial, and residential power generator sets, as well as automatic transfer switches, fuel tanks, and enclosures.

Honda develops a top selling line of portable home, recreational, and construction generator products.

John Deere produces industrial diesel engines that are used by generator manufacturing companies worldwide.

Kohler is worldwide manufacturer of on-site power systems, residential backup, mobile, and marine generators.

Briggs and Stratton provides portable and home generators.

Onan manufactures RV, marine, commercial, home standby, and portable power gensets.

SDMO is an international manufacturer of industrial diesel powered gensets.

Safety Precautions while using the generator
There are a few safety requirements that should be adhered to while using a portable generator:

• To avoid carbon monoxide poisoning when using generators one should never run generators indoors, including garages, basements and sheds. Get some fresh air immediately if you start to feel dizzy or weak.
• Generators pose a risk of shock and electrocution, if they are operated in wet conditions. It is advisable to operate the generator under an open, canopy-like structure on a dry surface where water cannot reach it or puddle or drain under it. One should operate with their dry hands.
• For connecting appliances to the generator, use of heavy-duty extension cords that are specifically designed for outdoor use is recommended. The wattage rating for each cord should exceed the total wattage of all appliances connected to it. Extension cords that are long enough to allow the generator to be placed outdoors and far away from windows, doors and vents should be used. The entire length of each cord should be free of cuts or tears.
• One should never store fuel for the generator inside the house. Flammable liquids should not be stored inside living areas rather it should be kept in properly labeled, non-glass safety containers. One should also not store the fuels near a fuel-burning appliance, such as a natural gas water heater in a garage. Gasoline spilled on hot engine parts can cause fire.

Ford Introduces Three New Light-Duty Engines for 2011 F-150 Pickup Trucks

The best-selling half-ton truck in the country is getting an all-new engine lineup for 2011. Ford is replacing its legacy two-valve and three-valve 4.6-liter V-8 twins and the venerable three-valve 5.4-liter V-8 in the F-150 with technically advanced six- and eight-cylinder engines that Ford says will be the most fuel-efficient in the industry. The truck maker is also shifting exclusively to six-speed automatic transmissions for every powertrain.

Six-cylinder engines are the unloved stepchildren of the half-ton segment. These entry-level mills have significantly less power and are only marginally more fuel efficient than most available eight-cylinder engines, making them an unpopular choice to power a full-size truck.

Ford dropped its old 4.2-liter V-6 from the F-150 lineup after 2008 – offering only V-8 engines – because even its two-valve 4.6-liter V-8 with a four-speed automatic was less thirsty yet delivered more power.

But for 2011, V-6 is no longer a dirty word when it comes to full-size pickups.

Ford’s all-new Duratec 3.7-liter V-6 is the new base engine for the F-150. It’s rated at 300 horsepower and 275 pounds-feet of torque on regular unleaded fuel, though it will also burn E85 ethanol. It debuted earlier this year in the 2011 Ford Mustang, where it’s rated at 305 hp and 280 pounds-feet of torque. It’s also shared with the Ford Edge crossover.

Fleet owners are most likely to be its customers, looking for a low-cost capable pickup. Ford Ranger buyers are another potential target for the 3.7-liter V-6, when production of Ford’s compact pickup ends in 2011. Ford also says it will be the most fuel-efficient engine in the segment.

The dual-overhead-cam, all-aluminum, 60-degree V-6 is stuffed with technology. Starting with composite upper and lower intake manifolds to feed air to the engine, the engine’s heads have four valves per cylinder (two intake, two exhaust) that are combined with twin independent variable camshaft timing, or Ti-VCT in Ford speak. Ti-VCT varies valve actuation throughout the power band so there’s improved torque at the low end, cleaner emissions and better fuel economy throughout the rpm range. Bucket tappets that actuate the valves are low-friction and designed to boost mileage further.

The 3.7-liter V-6 also features a die-cast aluminum deep-sump oil pan that helps the engine go up to 10,000 miles between oil changes. The high use of aluminum throughout the engine saves weight and further improves fuel economy.

With all of this power, maximum trailer towing with the 3.7-liter V-6 is up to 6,100 pounds. That’s more than the maximum 5,760 pounds for today’s Ranger.

The 3.7-liter V-6 will be available for all cab configurations, up to a two-wheel-drive SuperCrew – the only V-6 full-size pickup with a crew cab.

Which F-150 Models Get It? XL, STX, XLT

Availability? Fourth quarter of 2010

3.5-liter EcoBoost V-6

Ford isn’t bringing back just one V-6 for 2011. It’s offering two. However, the second six-cylinder engine has about as much in common with the first as Jaws does with Flipper. And this is one six-cylinder with lots of teeth.

As originally announced in 2009, the 3.5-liter EcoBoost V-6 will be the first application of Ford’s gasoline direct-injection twin-turbo technology in a half-ton pickup. It’s Ford’s effort to shrink engine displacement for improved fuel economy while delivering tons of low-end power.

How much power? Ford is still coy, but we estimate the 3.5 will be about 400 hp and 400 pounds-feet of torque, enough to give it best-in-class towing and highway fuel economy. Ford says it will be able to pull up to 11,300 pounds, which is today’s maximum towing rating for the F-150. That’s amazing when you imagine its displacement is smaller than a pair of 2-liter bottles of Coke.

EcoBoost V-6 performance is said to be diesel-like, with peak torque coming on early in the power band and staying flat throughout the rev range.

The twin-turbo setup should also prove ideal for towing at altitude, where a naturally aspirated engine can have difficulty feeding air to its cylinders.

In the engine lineup, the 3.5-liter EcoBoost and 6.2-liter V-8 will occupy the top two slots. Ford hasn’t said how much it will cost. It may carry a premium over the 6.2.

Official fuel economy and power figures will be revealed during the State Fair of Texas in September. We’ll be there to bring you initial driving impressions, too.

Which F-150 Models Get It? All except for Harley-Davidson and SVT Raptor

Availability? First quarter of 2011

5.0-liter V-8

The 3.7-liter V-6 isn’t the only engine that the F-150 will share with the Mustang. It’s also getting the all-new 5.0-liter “Coyote” V-8.

The engine, which makes 360 hp (at 5,500 rpm) and 380 pounds-feet of torque (at 4,250 rpm), is positioned as the midrange engine choice for the F-150, below the 3.5-liter V-6 and conventional large-displacement 6.2-liter V-8.

Although the 5.0 produces more power than the outgoing 5.4-liter V-8, it won’t carry as high a tow rating. Its maximum will be only 9,800 pounds trailering, instead of 11,300 pounds. Peak torque has also moved up the rpm band, from a low 3,500 rpm in the 5.4-liter V-8.

“It’s positioned as an entry-level V-8,” said Mike Harrison, Ford V-8 engine programs manager. “It’s one step up from the 3.7-liter V-6. It’s really replacing the [discontinued 2010] three-valve 4.6-liter V-8.”

The F-150’s 5.0 benefits from some of the work done on the Mustang’s 5.0, which was engineered with the goal of being able to add a supercharger at a later date to boost performance, Harrison said.

“We put a forged crank and good rods in [the Mustang’s 412 hp, 390 pounds-feet 5.0 V-8],” Harrison said. “The head bolts are upsized. The main bearing bolts are upsized. That then lends itself for a very robust truck application.”

The 5.0 also uses Ti-VCT to continually optimize power and fuel economy during two cam timing schedules – one for performance and one for mileage. It’s also E85 ethanol capable, which gives it increased power figures (and lower fuel economy), though Ford won’t say by how much.

There are some physical changes, too. The exhaust headers for both engines are different from each other for extra durability in the F-150. Instead of the Mustang’s unique tubular stainless-steel exhaust headers, the F-150 uses thermally tougher conventional cast-iron exhaust manifolds that give it a small loss in low-speed torque and performance, which has to recovered to improve the driving experience and meet long-duration high temperature work demands – such as during cross-country towing. To do that, Harrison’s team shrank the duration of the intake cam duration from 260 degrees to 240 degrees, dropped the compression ratio from 11:1 to 10.5:1 and advanced spark timing for extra low-speed torque. The changes also help F-150 owners run their 5.0 V-8 with regular unleaded instead of super unleaded for optimal performance in the Mustang.

The F-150 5.0 also gets a heavy-duty oil cooler that's not shared with the Mustang.

Which F-150 Models Get It? All except Harley-Davidson and SVT Raptor

Availability? Fourth quarter of 2010

6.2-liter V-8

The single-overhead cam 6.2-liter V-8 that debuted in the 2010 Ford F-150 SVT Raptor is rated at a brawny 411 horsepower and 434 pounds-feet of torque. But compared to the other engines for 2011, it’s a bit of a throwback. It has two valves and two spark plugs per cylinder, a cast-iron engine block and aluminum cylinder heads. It also features a cast-iron crankshaft, forged steel connecting rods and cast-aluminum pistons. "Powered by Ford" is proudly embossed on the valve covers.

Since it only has a single cam per cylinder bank, instead of Ti-VCT, the 6.2 uses dual-equal variable cam timing, where the intake and exhaust valve opening and closings are phased at the same time.

We expect that in the next two to three years Ford will revise the 6.2 with new heads, four-valves per cylinder, direct injection and Ti-VCT for improved mileage and power.

For now, this engine is a brute force power lifter that’s rated to tow up to 11,300 pounds (depending on model), the same as the EcoBoost 3.5-liter V-6.

Which F-150 Models Get It? Harley-Davidson, SVT Raptor and Platinum and Lariat with Max Trailering Packages

Availability? Now

Six-Speed Automatic Transmission

Every engine for 2011 will be paired with the F-150’s existing 6R80 six-speed automatic transmission, but Ford has improved the gearbox as well, with features inherited from the 2011 F-Series Super Duty HD pickups.

Progressive Range Select allows a driver to reduce the number of available gears so it’s easier to tow up a grade and hold a specific top gear without worrying about the truck upshifting and getting bogged down in a higher gear.

There’s also a manual shift function, which lets a driver operate the truck like it had a manual transmission. The driver can shift whenever needed, as long as it doesn’t over-rev the engine.

The transmission also receives new ratios so it can operate with a lower final drive ratio for improved highway mileage – we’re waiting for the final ratios from Ford and word about rear axle changes – tow/haul mode has been re-calibrated for improved grade-shifting during descents and there’s also a new one-way clutch for smoother 1-2 and 2-1 shifts between the first two cogs.

source : www.pickuptrucks.com

Wind Tunnel Basic Types

Open Circuit

The open circuit wind tunnel is the simplest and most affordable to build. In these tunnels air is expelled directly into the laboratory and typically reingested after circulating through the lab, though some tunnels utilize instead a compressed gas source. In addition to their low costs, open circuit tunnels are also advantageous because they have are relatively immune to temperature fluctuations and large disturbances in return flow, provided that the volume of the laboratory is much greater than that of the tunnel.

There are two basic types of open circuit tunnels, “suckdown” and “blower,” and the two are most easily differentiated by the location of the fan. Blower tunnels are the most flexible because the fan is at the inlet of the tunnel, so the test section can be easily interchanged or modified with seriously disrupting flow. These tunnels are so forgiving that exit diffusers can often be completely omitted to allow easier access to test samples and instruments, though the omission often results in a noticeable power loss. Suckdown tunnels are typically more susceptible to low frequency unsteadiness in the return flow than blowers, though some claims have been made that intake swirl is less problematic in these tunnels because it does not pass through the fan before entering the test section.

Closed Circuit

As the name implies, closed circuit tunnels (also called closed return) form a enclosed loop in which exhaust flow is directly returned to the tunnel inlet. These tunnels are usually larger and more difficult to build. They must be carefully designed in order to maximize uniformity in the return flow. These tunnels are powered by axial fan(s) upstream of the test section and sometime include multistage compressors, which are often necessary to create trans- and supersonic air speeds.

Closed circuit wind tunnel.