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Tech Education Directory: New England Tech Education Directory, Part II
Mass High Tech has compiled listings of New England colleges, universities and training centers for technology professionals. Here is a compilation from the New England Tech Education Directory for schools in New Hampshire, Rhode Island, Vermont and part of Massachusetts.

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i have a 92 buick regal grand sport. the care was leaking radiator fluid and water but not from the radiator ?

now the steering locked up and all the gauge lights are on. another thing is the belts arent working and its throwing something up from the belts when the belts where turning. now the battery light says there is no juice, and there car is dead. what is the problem, is the car a piece of grap now ??? please help!

You need a new water pump and new belts. The water pump threw coolant on the belts and they are slipping on the pulleys.
Not a piece of grap, just needs a new water pump and belts.

Sunglasses and Ultraviolet Light – a Guide to Choosing Your Sunglasses

 

 

There are many different types of tint available today for your sunglasses, and choosing the correct tint can be rather confusing. This article guides you through the different colours and types of tint, allowing you to make an informed choice about the most suitable tint for your own personal needs. We also examine the characteristics of ultraviolet light and why protection is important.

Light travels as electromagnetic waves, similar to the waves on the sea, with peaks and troughs. We specify the different colours of light by the wavelength of radiation they emit. (The wavelength is the distance between two adjacent peaks or troughs of that wave). As light has a very small wavelength, these measurements are extremely small and are measured in units called “nanometres†(nm), where a nanometre is one billionth of a metre!

Think of the colours of a rainbow, with red on the outer part of the curve and blue/violet on the inside. Red has a wavelength of 710nm, green is 500nm, and blue/violet is 400nm. So the wavelength is getting smaller as we pass from the red end of the visible spectrum through to the blue end. Ultra-violet lies beyond the blue/violet band, between wavelengths 400nm to 100nm, but the human eye cannot usually see light with a wavelength smaller than 400nm, making ultra-violet light invisible to us – so we call it ultraviolet radiation.

Although UV radiation is invisible to humans, many animals and insects can detect UV light, which they use in helping to find prey, etc. For example, kestrels can detect the UV light given off by the urine trails that field voles make as they move around, so from high up in the sky, when these birds of prey find many criss-crossing urine trails on the ground, this indicates a good place to hunt for the voles.

One possible reason why we cannot detect UV light is that if the crystalline lens in the human eye has evolved to only focus on a limited range of colours, this helps to give us a sharper image of what we see, whereas if we could focus over a larger range of wavelengths this could lead to chromatic aberration, a distortion of vision that would reduce image clarity.

Ultra-violet radiation can be divided into three main bands or groups, depending on wavelength :-

1. UVC radiation -100 to 290nm

UVC rays are absorbed by the all-important ozone layer that surrounds the Earth as part of the outer atmosphere, thus preventing this radiation from reaching the ground.

2. UVB radiation - 290 to 320nm

UVB radiation is the most dangerous, as this is what can damage the eyes and cause sunburn to the skin. UVB is the cause of snow-blindness, where the radiation induces a photochemical reaction in the cornea and overlying conjunctiva after a few hours exposure, producing swelling of the cornea (oedema) and inflammation of the surrounding tissue. The swollen, oedematous cornea becomes cloudy – hence the blurred vision, and also very painful. There is photophobia (dislike of any exposure to light) and spasm of the eyelids. It usually lasts for a couple of days, and is only alleviated by using local anaesthetic drops, amethocaine 1%, to reduce the pain, and adrenalin drops 0.01% to relieve the congestion.

UVB radiation does not pass through glass, so a simple glass lens would prevent it from reaching the eye. Polycarbonate, a type of plastic sometimes used for spectacle and sunglass lenses, also cuts it out completely.

Some believe that regular exposure to UVB radiation can, over a period of time, contribute to cataract formation at an earlier age than normal, and may also cause the development of pterygia, which are growths of tissue that encroach over the cornea from the sides.

UVB radiation varies with the time of day, being most intense between 10am and 2pm, when the sun is at its brightest. It is stronger at high altitudes, and more intense near the equator, due to the more direct nature of the sun’s rays in this region.

3. UVA radiation - 320 to 400nm

In contrast to UVB, which varies in intensity with the time of day, UVA radiation is more constant with less variation. Also it is not blocked by glass, and so can still pass through to reach the eye. However, the crystalline lens of the human eye absorbs most of the UVA radiation, so hardly any UVA is allowed to pass through to the back of the eye. There is no known evidence that UVA causes harm to the eye, although scientific opinion is still divided and under debate.

UVA radiation was originally thought to have only a minor effect on the skin, but recent studies have shown that whilst UVB causes damage to the surface layers of the skin as sunburn, the UVA penetrates into the deeper layers of the skin, causing damage further down.

Reflected Light

UV radiation not only reaches us directly from the sun, but a considerable portion is reflected from various surfaces around us, to reach our eyes and skin indirectly. Fresh new snow can reflect the most, with up to 80% reflected UV rays. On holiday on the beach, sand can reflect 15% UV light, along with concrete buildings and walls etc. A foaming, frothy sea reflects 25%, whereas still water and normal ground reflects around 10% UV radiation.

Children and UV Light

As UV damage tends to build up over many years of exposure, such as going on holiday to warm bright climates or playing outside on a sunny day, children and young adults are at particular risk, and you should always consider some sort of eyewear protection for them even though they seem to cope with bright light better than us adults (when playing at the seaside, for example).

Wearing a peaked cap is not really enough protection, as a lot of the UV radiation is reflected off the ground (see earlier “reflected lightâ€) and straight into the eyes, especially on a sandy beach. Make sure the sunglasses have a full UV protection.

Choosing the Best Tint for Your Sunglasses

Ideally, you should go for a tint that absorbs at least 98% of both UVA and UVB radiation. If you see a label “UV400â€, this means that all radiation up to 400nm (thus all UV radiation) is absorbed or blocked by the lens.

Dark grey, grey/green, or brown are the three main colours to choose from, and is a personal preference. I, myself, prefer grey or grey/green, because it seems to keep the colours true to life, but many people like brown because it can enhance the contrast and so help to make things appear sharper. Amber coloured tints are used to block out blue light, which again enhances contrast, so making the image sharper. Amber tints can therefore be used for skiing, sailing, flying, target shooting etc.

Lenses made from polycarbonate absorb most UV radiation, and wrap around designs are good for preventing light from entering the eye from the sides.

Different coloured tints are available to enhance vision and improve visual comfort for many activities. Sunglasses are very important as they reduce glare and protect against harmful ultraviolet radiation.

The main tints available can broadly be divided into neutral grey, polarising, yellow-brown, green, red and photochromic.

1. Neutral Grey

This filters out all wavelengths of light by an equal amount, and so colours appear more natural looking than with tints of other colours. Grey tints are good for activities where subtle colour differences are important, such as golf, mountaineering and skiing.

2. Polarised tints

Polarised tints are good for reducing glare from reflected light bouncing off surfaces such as water or wet roads, making them a good choice for fishing, water-sports, driving or cycling (on wet surfaces). However, polarised lenses might also reduce important details in skiing or golf.

3. Yellow/Amber tints

Yellow or amber tints help to increase contrast by blocking out the blue end of the visible spectrum, resulting in a reduction of blue light scatter. They enhance differences in contour and make things appear brighter in low light levels. This makes yellow or amber tints good for shooting, snow sports, driving or cycling.

4. Green tints

Green tints help to enhance the background, which makes them a particularly good choice for golf, tennis and some forms of shooting, where the object needs to show up against the background.

5. Red tints

Red tints enhance objects at the red end of the spectrum, and can be used in clay-pigeon shooting where the target is orange, in skiing to give contrast to the changes in reflected light, or in motor sports to reduce the reflected glare from the road.

6. Mirror tints

Mirror tints limit glare, increase absorption and reduce infra-red, thus reducing the build-up of heat. Mirror tints are good for snow sports, water sports, cycling and running.

7. Anti-reflection coatings

Anti-reflective coatings minimise lens reflections, especially from the back surface, and are recommended for racket sports, fishing, shooting and archery.

8. Photochromic tints

In photochromic tints the darkness of the tint changes according to the light levels, most commonly between around 20% to 80% transmission. Generally, two photochromic colours are available, brown or grey. Photochromic lenses are good for sports played in variable light levels, such as golf or tennis.

The following list gives a summary of suggested tints for different sports and activities:-

• Cycling - polarising, yellow/amber

• Golf - green, neutral grey, yellow/amber, brown

• Shooting – reddish-brown, orange, yellow to brown, green

• Skiing – brown, red/orange, neutral grey

• Tennis – green

• Fishing – polarised

• Motor sports – polarising, yellow, red

• Water sports - polarising brown or grey

• Running - green, neutral grey

• Football, and fast moving ball sports - amber

I hope this guide has been of some use to you, but please remember that it is only a guide, so feel free to take it “lightly†(excuse the pun – I couldn’t resist) as the colour of tint you choose for your sunglasses is very personal, so if you prefer a certain colour of tint that falls outside of these guidelines - don’t worry. As long as it blocks out all the ultraviolet light (UV 400) then that’s all that matters. Enjoy your sunglasses!

About the Author

Stephen Jenkins is a UK optometrist who qualified in 1990 and has his own practice (Watson and Jenkins Opticians) in Chesterfield, Derbyshire. The practice also sells designer sunglasses online and is an official supplier for Oakley, Rayban, Gucci and many more. Advice on ultraviolet light and how to choose the correct tint for your sunglasses. Regular news updates from the eyecare world, such as the latest advances in gene therapy for treating blindness. Free fast UK delivery and low cost worldwide shipping. Visit http://opticalreflections.co.uk/

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When do vehicles need emergency vehicle lights?

It is common knowledge that emergency vehicle lights, are lights sported by emergency vehicles like ambulances, fire engines, police vehicles, or towing trucks. But when do these vehicles need emergency vehicle lights? Do they need them when they are moving, or do they need them when they are stationary? The answer is that they may need them both when they are moving or when they are parked, depending upon the type of work they are doing, or the place in which they are functioning.

More often, it is the moving vehicles that sport emergency vehicle lights. Police vehicles that are chasing criminals, or fire engines rushing to douse a fire breakout, or an ambulance taking a patient to a hospital, need to flash its emergency lights at full power and activate their emergency sirens at full volume. In those instances the emergency vehicle lights and sirens are signaling to the other vehicles on the road to give way because the light-sporting vehicles have to rush to their destination to avoid a crisis or to save lives.

Other vehicles have to give way at such a juncture because the job that those emergency vehicles are doing are more important than what the other vehicles on the road could be doing. Here it is their purpose that gives these vehicles the right to use emergency vehicle lights and often flout traffic rules to get ahead to where they are going. The same vehicles, when returning from an emergency, have no right to flash emergency lights or run red lights. For example, an ambulance that is returning from a site of emergency back to the hospital after the work has no right to make use of emergency vehicle lights to get ahead.

Using this parameter, parked vehicles would never need to use emergency vehicle lights because the very fact that they are parked conveys that they are not in a hurry. However, parked vehicle in an insufficiently lit street can be more dangerous than a moving vehicle that could be flouting traffic rules. These vehicles have to use emergency vehicle lights to save themselves and other vehicles on the road. Examples of these are delivery trucks, construction site vehicles, towing trucks, or even private vehicles that have broken down unexpectedly in the middle of the road.

Delivery trucks may have to be parked anywhere on the street at any time of the day. They have to make themselves and their purpose conspicuous by using emergency vehicle lights to avoid confusion to other vehicles coming that way. Likewise, construction sites are most often unlit and are likely to be full of large vehicles and equipments. These vehicles should sport emergency lights throughout the night to help other vehicles to avoid them. Not just other vehicles, but even pedestrians, and even stray animals will be helped by the emergency vehicle lights that these vehicles sport.

Above all, even private vehicles, that had to stop on the middle of the road as a result of an unexpected emergency, should use emergency vehicle lights,. This is necessary to avoid collision and also to seek help, if necessary. Emergency vehicle lights that can be mounted temporarily on the dash or deck are available for such emergencies, and all vehicle owners should ideally store one of them in their vehicles.

Extreme Electrical Dynamics is a one-stop shop for emergency vehicle lights and many other items like Strobe Lights, Flashlights, Sirens, Deck Lights, emergency vehicle lights, etc. Please visit the site for more details of various items available - http://www.extremetacticaldynamics.com/

About the Author

I am a Microsoft Certified Professional. I conduct Training and Certification Guidance for
Microsoft .Net Certification Courses through my training institute-Sierra Infotech. I also own and manage a
SEO Company and
article Directory.

Howard praises India, pushes ICC presidency bid
Former Australian Prime Minister John Howard on Sunday offered an olive branch to India but refused to stand aside as Cricket Australia's candidate for the next ICC presidency.

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