Comet Enthusiast

Spider Secondary

 

Insect Prevention - Foodborne Diseases

Insect Pests

All kinds of insects attack and harass people human. The most common of which are directly attack the body lice and itch mites. Less frequent are the bugs and spiders. In the forest and in tropical areas mosquitoes and chiggers, ticks and biting flies bother humanity.

Chiggers

These insects are known scientifically as Trombicula irritans. They are attached to the skin. The skin becomes irritated, and an intolerable itching begins. Red spots and blisters. Chiggers do not penetrate the skin, but inject a substance that dissolves and softens the tissues, and this causes the itching.

Chigger infestation can be avoided by placing the flour sulfur powder sulfur in the media or undergarments to enter the high grass or weeds. Protection can be had with the use of leggings and closing the bottom of the pants.

If you have been seriously bitten by the chigger, wash skin with soap and water and let foam stay on skin tenfold minutes before removing. Then either anti-itch preparations can be applied to help control the itching until it heals.

Insect repellents, such as DDT, freon, with pyrethrum, and similar preparations can be used to eliminate bugs from infested areas, as well as mosquitoes, moths and other insects.

Lice

The louse is a resident upset in the human body. Lice are a common discomfort among children in schools that health departments often give instructions special control. Several specialized blends have been developed to eliminate head lice, body lice and pubic lice.

To kill lice head, the regular crude oil or kerosene mixed with sweet oil or olive oil, half and half, and rub on the scalp. Then cover hair with a cloth for at least two hours or better overnight. Oil is toxic and flammable. Never let the hair come to any open flame, like a stream gas or a lit match. When the muslin is removed wash the hair and scalp with soap and warm water and rinse well with clean water. Repeat this process as long as live insects are found in the hair. Nits may be removed by wetting the hair thoroughly with hot vinegar, then comb with a fine tooth comb. Dry hair completely after such treatments before leaving. For body lice, body, all clothing and bedding may be thoroughly dusted with DDT powder suitable.

Pubic lice are commonly called "crab." specialized creams, including former "blue ointment" and "ointment Gammexane" are used, rubbed thoroughly into the infested areas. If the lice and enter the tabs, which should be passed, with her wits, by a forceps. Itch the bites of lice and other insects can be controlled with creams or lotions that contain small amounts of phenol or menthol or camphor, such as 1 percent of phenol or calamine lotion menthol or camphor phenol in mineral oil.

Spider Bites

The only poisonous spider in the Western Hemisphere is the black widow. When a person is bitten by a spider the first step is to stop the absorption of venom into the circulation. The wound can be disinfected with tincture of iodine or any other good antiseptic. If any considerable amount of poison taken into the body, the bite area can be subjected to suction.

Following the bite of the black widow spider, you feel a sharp pain. Then comes the swelling and redness at the bite, and all the body reacts with nausea and weakness, trembling of legs, and even abdominal cramps. Young children may have difficulty breathing and even stupor or seizures. The serum or antitoxin has been developed but it must be guaranteed in most cases the health department or directly from the manufacturer.

Bedbugs and fleas

A bed bug bite usually appears as a blister with a red rose in the center. Chop and sometimes has a burning sensation. Bedbugs do not live in the body but infest human beds, bedding, upholstered furniture, walls, woodwork and curtains. Usually come out at night, attracted by the smell of human body. To the being crushed, the bug gives off a foul odor.

Because bed bug bites itch, the bite area can be masked by the results of scratching and secondary infection. Those who wear pajamas, if bitten, are usually affected in the areas around the ankles, wrists and neck. The only treatment requirements for a bug bite is the application of calamine lotion with menthol or camphor or phenol to relieve itching. Any lotions generally used for itching can be applied to flea bites.

The fleas that infest rodents can transmit diseases like the plague. Fleas are found all parties. You can pass to humans from dogs, rats and pigs. When humans are bitten by fleas from the source of infestation must be found and eliminated. powder fleas are readily available at any pharmacy.

Scabies

Scabies, also called the Seven Year Itch, itch Cuban itching prison, and similar names, is caused by the itch mite. It extends poverty in the midst, overcrowding and filth. Usually, scabies is transmitted contact the body.

The scabies mite does not have the same habits that the body louse. The body louse lives in clothing and feeding on the body, but scabies mite lives in the body under the skin. Any infestation of clothing or bedding for the scabies mite is accidental. The scabies mite tunnels under the skin. If the skin is clean and free from crusting and secondary infection of the invasion spots can be seen. The female mite enters the skin through the follicles follicles and moves along a tunnel she creates. In the inner end of the tunnel that lay their eggs. After three to five days the eggs hatch and larvae the burrow along the new tunnels or out of the old.

The most common areas of infestation are among the fingers on the back of the hands, elbows, under arms, groin, under breasts, around the navel, sexual organs, shoulders and back.

After that the body has been scrubbed with hot water, the emulsion is applied with a brush or with a barrel of insecticide and the whole body is covered from the neck down. The emulsion allowed to dry, and after ten or fifteen minutes a second application is painted on. The patient puts on his clothes and bathing refrains clock. Then it is given another table with benzyl benzoate emulsion. After a second clock period of its mandate to bathe and change into clean clothes all. If these instructions carefully carried out 95 percent of patients are cured. The failures are given another course of treatment. The ointment called Gammexane, which is also exachlorocyclohexane effectively used against scabies. New treatments tend to replace the previous use of sulfur ointment, ointment, pyrethrum and rotenone ointment.

The mosquito bites

The mosquito is a test of Kipling's famous statement that "the female of the species is more deadly than the male. "The male mosquito does not bite. The female mosquito is out of the blood. The mosquito does not hurt, but saw through the skin.

Researchers have proved that mosquitoes prefer to bite some people rather than others. We found also that some people react strongly to mosquito bites, while others do not react at all. The attractiveness of an individual to mosquitoes varies from time to time. The biting mosquitoes prefer crowded places, rather than those with only a few people or places that are empty. Mosquitoes are more attracted by many ties or unwashed that some people who are sleeping and are thoroughly washed. thorough cleaning with soap and water reduces the attractiveness of any individual for mosquitoes. Mosquitoes are attracted by heat, by the lights night and dark objects during the day. Dark clothing is more attractive than light clothing and mosquito rough clothing is more attractive than the soft clothes. Mosquitoes prefer humid to dry weather, but during the cold season that prefer dry weather to wet weather. Mosquitoes prefer children to adults and men women.

Mosquitoes transmit malaria, yellow fever, West Nile virus and a number of other diseases. The mosquito can be eliminated by removing stagnant pools of water around, spraying water surfaces with oil, the widespread use of DDT, and other engineering well-established health. The itchy mosquito bite can be controlled by using a percent of menthol or phenol in calamine lotion or by application of antihistamines such as creams neohetramine, neoantergan, thephorin, pyrabenzarnine, Benadryl, diatrin, and others.

About the Author

David Crawford is the CEO and owner of a Natural Male Enhancement company known as Male Enhancement Group which is dedicated to researching and comparing male enhancement products in order to determine which male enhancement product is safer and more effective than other products on the market. Copyright 2009 David Crawford of http://www.maleenhancementgroup.com. This article may be freely distributed if this resource box stays attached.

Can secondary consumers eat other carnivores?

Be secondary consumers are carnivores that eat herbivores. But can also eat other carnivores? I know teritary consumers are carnivores that feed on other carnviores. But my examples for each seem to overlap and I am very confused. Primary consumers: rabbits, cows, sheep, horses, grasshoppers SECONDARY CONSUMERS: foxes, spiders, snakes, seals, birds. tertiary consumers:??

Well in this case, if all animals have to work with i would consider the fox by the consumer tertiary resistant chains up to a third level consumers are not as common, usually stops at the consumer side, you can add a wolf or mountain lion, which can be a tertiary consumer in extreme cases when they can find food, but usually tertiary consumers are vultures or other animals that feed on dead matter. Hope this helps

Spider Secondary

Secondary Mirror Holder

 

Drivers, Keep Your Eyes on the Road: Cell Phones and Other Driver Distractions

The list is endless: dialing a hand held cell phone, conversing on a cell phone, operating a PDA or reaching for it, eating, drinking, smoking, daydreaming, "rubbernecking", applying makeup, combing hair or brushing teeth, removing or putting on jewelry to name only a few. We've all seen it. People engaged in secondary tasks while they drive cars and trucks on our country's public roads and highways. Driver inattention is a leading cause of vehicle crashes. The situation only seems to be getting worse.

Does it really matter whether you take a few seconds to run a comb through your hair or dial a friend's phone number while you drive down the road? The answer is yes, it does. Studies conducted for the National Highway Traffic Safety Administration demonstrate a direct relationship between driver inattention and automobile accidents. Just glancing away from the roadway for more than two seconds can increase your risk of a crash or near crash at least two fold over normal, attentive driving. Engaging in more complex visual or manual tasks while driving can raise your crash risk even higher. It goes without saying that driving while drowsy is always dangerous and increases the risk of an accident.

Remember, however, not every glance away from the road ahead is dangerous. Quick looks into rear or side view mirrors to check for approaching vehicles or other obstacles can actually decrease your risk of a crash. The motor vehicle driver who periodically scans his surroundings, specifically looking for potential hazards, is a safer driver.

Drivers have been primping, smoking and eating behind the wheel ever since motor vehicles took to the roads over a century ago. Why is there so much fuss over inattentive drivers now? Within the last two decades, cell phone use has increased to the point where there are now over 250 million people in the United States who are wireless communication subscribers. Many of these subscribers regularly use their cell phones while they drive. After all, most everyone wants to stay in touch with friends, relatives and associates. Teenage and young adult drivers are especially addicted to the new technology. They keep their ears glued to cell phones and spend lots of time text messaging friends. Unfortunately, all this friendly communication translates into driver inattention, and it comes at a price. 

A 2007 Nationwide Mutual Insurance Co. survey of 1200 drivers found that 73% of the drivers surveyed routinely talk on cell phones while driving. This high incidence of cell phone traffic means there are more distracted drivers traveling our highways. The more inattentive drivers there are on the road, the more frequently these drivers will be involved in accidents. This doesn't mean talking on a cell phone while driving is the most hazardous of driver distractions. Drivers who reach for falling objects like a coffee cup or who open a glove compartment are actually at greater risk of a car crash. Nonetheless, driving while you are conducting a cell phone conversation is risky business. A recent University of Utah report declared that the impairment level for persons driving while talking on cell phones is comparable to that of motorists driving while intoxicated at the legal blood-alcohol limit.

It is tempting to conclude that carrying on a cell phone conversation is safer than handling and dialing a cell phone. After all, once the phone connection is made and the conversation begins, you're keeping your eyes on the road ahead, aren't you? The answer to this question is "no". Studies show it is not just the physical act of reaching for the phone and dialing that raises the risk of involvement in a crash. It is also the mental concentration that comes with both listening to someone speak to you and formulating your verbal response. When you're absorbed in a phone chat with a friend, your mind is focused on the conversation, not the road. Despite this reality, however, states are taking action to ban hand-held cell phone use based on the rationale that hands-free cell phone conversations are safer. In July, 2008, California will begin enforcing a new law banning hand-held cell phone use by non-commercial drivers. The states of New York, New Jersey, Connecticut, and Washington, D.C. have enacted similar legislation.

At present, these states are in the minority. Although more and more state legislatures are taking action to curb cell phone conversations by drivers, few states ban cell phone use altogether. Where there are bans, certain professions or jurisdictions are sometimes exempted. Nevertheless, more and more states are identifying specific categories of drivers for special regulation. Because cell phone use and text messaging is highest among teenage drivers, states have become pro-active in dealing with this age group. Seventeen states, including Virginia, Texas, and New Jersey plus Washington, D.C. regulate cell phone use by novice drivers depending on their age and/or whether or not they have a learner's permit or a provisional license. Fifteen states prohibit cell phone use by school bus drivers.

To date, legislators in Virginia have focused only on cell phone use by young drivers. Enacted in 2007, Virginia Code Section 46.2-334.01 provides that, "except in a driver emergency or when a vehicle is lawfully parked or stopped, the holder of a provisional driver's license shall not operate a motor vehicle on the highways of the Commonwealth while using any cellular telephone or any other wireless telecommunications device, regardless of whether such device is or is not hand-held." This provisional driver's license restriction expires on the holder's 18th birthday. Violation of the statute constitutes a traffic infraction. Multiple offenses may result in suspension of the juvenile's privilege to drive for a period not to exceed six months, in addition to other penalties a judge might impose.

Of course, it is not only cell phone conversations that put motorists and others at risk. When a driver is drawn into conversation with his passengers, for example, his ability to react quickly to trouble on the roadway ahead is also impaired. He is likely to brake more slowly and to follow other vehicles too closely. The bottom line is that, although cell phone use is a common driver distraction which raises the risk of an accident occurring, drivers who habitually engage in other inattention-related activities are also likely to be involved in crashes.

Never decide whether or not to engage in any distracting activity based on what you perceive to be its level of danger. In other words, don't reassure yourself by thinking it isn't as dangerous to make a hands-free cell phone call as it is to eat a cheeseburger while you're at the wheel. Remember that a few seconds of driver inattention for whatever reason can lead just as easily to a collision with a Mack truck as it can lead to a crash with a Dodge Neon. It simply depends on which vehicle is in your vicinity at the moment you become distracted. In the end, it is the severity of the injuries you and others sustain in a crash that really matter, not the degree of danger you may attach to the diversion. Stay safe. Watch where you're going!

About the Author

Elizabeth M. Allen, of the Virginia injury law firm Allen, Allen, Allen & Allen, has been engaged in the practice of personal injury law for over 30 years. Allen and Allen are experienced
car accident lawyers
and
Virginia injury lawyers
. They can be found online at: allenandallen.com

Secondary Mirror Holder

Spider Secondary Mirror

 

Trick or Treat...Beware of the Black Hat

I thought it might be a really good time to about White Hats and Black Hats, so let’s start off with some old-fashioned definitions:

White Hat Practices:  Ethical SEO practices.  White Hat refers to honest, above-the-board SEO techniques used by well-meaning industry experts to help optimize a website and its pages and to realize higher search engine rankings and drive more qualified traffic to that site.  These practices are wholeheartedly approved by Search Engines and the SEO industry at large.

Black Hat Practices:   Unethical SEO practices.  Black Hat refers to deceptive SEO techniques employed by companies looking to “trick” the search engines into realizing higher engine rankings.  These practices are not acceptable in any form to the engines and industry.

Black hat techniques are often employed by companies looking for a “quick fix” and aiming to temporarily spike search engine rankings for a given site.  These practitioners are fully aware that their success will only be fleeting, because that site will be blacklisted or banished altogether from the major search engines once their unsavory methods are uncovered.  Companies caught using black hat techniques will immediately suffer a sharp drop in engine rankings, and long-term damage to their brand and reputation.  Companies seeking SEO support need to better appreciate how damaging black hat techniques can be to the reputation of their company, their brand and/or their website.  They are advised to steer clear of companies practicing these methods.

There are many black hat techniques, so let’s identify some of them.  This list is by no means exhaustive, but at least it will encompass some of the more well-known methods:

 

1. Cloaking – also referred to as “sneaky redirects”, this technique features to programs that send search engine spiders to website pages never viewed by users.
2. Doorway pages – also known as “crawler only” pages, these pages are created just for search engine eyes.  They try to artificially achieve high search engine rankings for a certain search term by repeatedly incorporating the same keywords and phrases in the body of text.  This technique is related to keyword stuffing.
3. Hidden Text – this method involves the placing of keywords on a page which match the background color of the actual site, thereby rendering this text completely invisible to the human site visitor.
4. Hidden Links – similar to hidden text techniques, this method involves placing links that are specifically designed to be spidered but cannot be viewed by the user.
5. Duplication – the creation of multiple pages, domains or subdomains which essentially contain duplicate content.  Creating multiple copies of the same page under different URLs is an example of this.  Many sites provide text-only or printer-friendly versions of pages which feature the exact same content as the corresponding graphic-rich pages.  If you do have duplicate pages, you are advised by the engines to employ a robots.txt file to at least block duplicates from being spidered.  Duplicate content is usually unintentional (such as a standard web page or print friendly page), but sometimes it is by design, such as when a site recycles content to artificially increase its traffic.

There is no doubt that black hat methods, often used in excess, can lead to short-term gains but invariably at the expense of long-term pain.  These underhanded techniques pose such a serious and pervasive problem for the SEO industry that search engines such as Google and Yahoo dedicate large parts of their Webmaster Guidelines to discussing them.  If these engines somehow catch you practicing black hat stuff, you might be kissing your online reputation goodbye.  You might be blacklisted and/or banned altogether, and it could be years, if ever, before you could once again gain engine respect.

A final word on black hats:  the industry does not talk about these practices that much, which for some only lends to their mystique appeal.  Sometimes the temptation to wear black hats is too great for SEO practitioners, and has actually led to the development of grey hat methods.  As you might expect, this compromising approach is not as honest as white hat but not as dishonest as black hat.   Let’s use an example from duplication to illustrate. An ethical white hat SEO expert would be inclined to establish just a single site, whereas an unethical black hat SEO expert would devise hundreds of mirror sites to link to the main site, thereby artificially exaggerating that site’s importance to users and tricking the engines.  A grey hat SEO person might establish secondary sites that are not duplicates of the original one, have some unique content and don’t lure users into visiting an irrelevant place.  This practice might actually add some content value and optimize the original site without raising the ire of the search engines.  As in life, there is always a middle ground in the SEO world.

About the Author

Question about a newtonion reflector telescope?

Hello

Can anyone who owns a reflector telescope tell me if the spider arms which hold the secondary mirror in place can be seen or obscure/blur the image you are viewing through the eyepiece?

Also I am thinking about purchasing a

Skywatcher EXPLORER-130P SynScan AZ GOTO Parabolic Telescope 209

view it here

http://www.telescopeplanet.co.uk/ViewProdDetails.asp?prod_code=PON08J000120

these run off batteries or a 12volt supply. My question is this . Can you manually use / move / adjust this when you have no power or batteries ie use it as a normal mounted telescope?

As I cant see any adjusters on the mount

Thank you

Provided the spider arms are thin (which they are in this design) you can see them only when the image is way out of focus. In focus, they cause four spikes to appear around very bright stars and a very slight loss of contrast, but this is too slight to be noticeable to most observers. I've used Newtonians for decades without any awareness of the spider diffraction. This is not a legitimate concern.

Unfortunately, most telescopes with electronic controllers are dead in the water if your batteries are depleted. I'm not sure about this particular design, since I've never used one myself, but most of the time with electronic scopes you can't use them without power. That's one of many good reasons for choosing a manual scope or one with digital setting circles, like the Orion IntelliScope series.

Spider Secondary Mirror

Telescope Secondary Mirror

 

Appreciating The Hyundai Santa Fe

The outcomes are in : the utterly reworked 2007 version of the Hyundai Santa Fe is bigger and better than previous models, boasting more power, bigger leg room, a more complex style and a classily designed interior that reflects a thoughtful eye for detail.

The Hyundai Santa Fe is perceived as a "crossover SUV" since it is assembled with a vehicle's unibody construction instead of the normal body-on-frame development of a regular wagon. Nevertheless , it is equivalent to any SUV out there in terms of practical, everyday use.

The 2007 Hyundai Santa Fe blends naturally into the burbs unlike last year's model, which sort of stood out like a sore thumb. It's also more roomy and can now accommodate up to seven passengers, especially with its mint third-row seating. During the past, third-row seating was an exclusive feature to minivans and larger utility vehicles, but not this year as manufacturers have worked out how to install a third row into smaller SUVs.

In addition, this year's Santa Fe also offers improved fuel economy and power, whether it's the GLS, SE or Limited trims. All Santa Fe models offer security features like 6 airbags, active front head restraints, Electronic Stability Control (ESC) with Traction Control System (TCS), an Anti-lock Braking System (ABS) with Brake aid and Electronic Brake-force Distribution ( EBD ) and the government-mandated Tire Pressure Monitoring System (TPMS). Within the year, Hyundai will also supply all Santa Fe models with standard XM satellite radio and optional Bluetooth hands-free telematics, and a non compulsory navigation system will be available sometime in 2007.

The Santa Fe GLS has a 185-horsepower 2.7-liter V6 engine, a five-speed manual transmission, 16-inch wheels, a 112-watt audio system with 6 speakers and an MP3 player, a lean and telescopic wheel, heated power side mirrors, power windows and doorway locks, remote keyless entry, and a roof rack. It also offers a choice for four-speed Shiftronic automated transmission, a power sunroof and heated front seats.

The Santa Fe SE has a 242-horsepower, 3.3-liter V6 and 5 gear Shiftronic automatic transmission, all-wheel drive, 18-inch wheels, an auto-dimming rearview mirror with compass, mist lights, and secondary audio controls on the steering wheel. There are also options for a power front seat with power lumbar, a power sunroof, heated front seats, and a rear-seat entertainment platform, featuring a 252-watt stereo system with 7 speakers and CD-changer/MP3 player functions, as well as a 115-volt power outlet.

The Santa Fe Limited has leather seating surfaces, heated front seats, a power front seat with power lumbar support, and dual-zone automated temperature control with an outside temperature display. Chrome accents on the grille and exterior door handles, as well as a body color rear spoiler, set the Limited model except for the SE and GLS. There's also a choice for a stronger 605-watt Infinity Logic 7 Surround Sound system with ten speakers and CD-changer/MP3 capability.

In a nutshell, the 2007 Santa Fe has everything a mid-size SUV wishes and at a more competitive price at that. Competition among SUVS is tight in terms of power, fuel use, space and other benefits, but the 2007 Hyundai Santa Fe fares well when ranged against other SUVs in the market.

What is your dream car? Check out some of the fastest and most exotic cars ever built at thesupercars.org and also take a look at pre owned hyundai tiburon.

About the Author

Do you like fast cars? If yes, you may also visit thesupercars.org to get more information about the fastest cars in the world. Also, you might want to check out used hyundai accent for sale.

Just three questions! plz help me!?

Which of the following is true about radio waves?

They have short wavelengths.
They have high energies.
They reveal hot gases.
They can penetrate dust clouds.

Which of the following best reduces atmospheric distortion?

primary mirror
adaptive optics
objective lens
eyepiece

Which of the following is the correct path of light through a reflecting telescope?

eyepiece → primary mirror → secondary mirror → eye
secondary mirror → primary mirror → eye → eyepiece
primary mirror → eyepiece → secondary mirror → eye
primary mirror → secondary mirror → eyepiece → eye

I don't know the last two, but
1) maybe the last one? the first 2 are the exact same thing, and both are wrong Radio waves have long wavelengths and low energy

Telescope Secondary Mirror

Secondary Mirror

 

How To Set Rear-View Mirrors To Eliminate Blind Spots

It may be surprising to learn that there is a better way of setting the rearview mirrors on the car. A quick test is that if one looks in your side mirrors and the side of the car is seen, it means that the mirror's capacity is not being used. Many people notably have a huge overlap between the side and center rear view mirrors, this is important. When the side mirrors are spread, no information is lost about what is present behind. Although valuable insight must be gained regarding what is present beside. Many driving schools recommend this new method; it also includes the BMW Performance Center in South Carolina.

What are Blind Spots?

Blind spots are the areas in which a vehicle cannot be seen from either the driver’s secondary vision, inside mirror or the side mirrors. Many drivers set their side mirrors in a way that they can just barely see the side of their car in the mirrors. By setting the side mirrors in a proper way and also using the rearview mirror can reduce the blind spots. However the size of these blind spots is still capable of hiding a vehicle.

How is Blind spot caused?

Perhaps one needs to change lanes or merge into traffic every time when while driving. These maneuvers of routine nature can cause dangerous situations because every vehicle has blind spots. According to a survey, there is an estimate of 630,000 lane change and merge crashes every year causing nearly 225 fatalities. Although not needed to say but the simple act of changing lanes or merging requires precautions and practice. Blind spots are also called blind zones.

How to eliminate blind spots

Following are some of the useful ways to remove blind spots;
-    One should lean his head over in a way that it almost touches the driver's window. Then the side mirror should be positioned on the car's left side so one can just see the rear or the car or the quarter panel in the mirror. It must be noted that this will have the mirror positioned farther out than one did not possibly had it before.

-    The center rearview mirror can be adjusted in a position that it faces the rear window’s center.

-    The head can be leaned to the right for aligning it with the center of the car. An example can be just between the two front seats at a considerable normal height. The right side mirror can be positioned from there so the rear quarter panel of the passenger side in can be seen in the mirror.

-    It can be noted while driving that a car passing by begins in the center of the rearview mirror. As it approaches, it moves to the side of the center rear view mirror. It appears on the side mirror at the same time. Because the mirrors are overlapped, this would mean that that there is no rear blind spot.

-    It can also be noted that the side mirrors will now capture a great extra amount of view that is in the lanes quickly next to the car. Turning the head for needed before for ensure if there was nothing in the lanes next to the car prior to changing lanes. But now, the side mirrors have much better productivity and better job of covering this blind spot on the sides.
Useful tips

Following are some useful tips;

-    At least one week should be given the new mirrors this way. It will initially seem strange in the beginning but soon one will get adjusted.

-    It should be noted that parallel parking becomes more difficult as one can see his car what is next to it in the side mirrors without moving the head.

-    Scanning the mirrors constantly instead of only checking them is helpful; particularly when one wants to change the lanes or pass the other will generally prevent someone from sneaking up. This mirror setting method of pairing with continuous scanning will help the driver to be aware every time of all those around.

Warnings

Following are some warning which one needs to give attention;
-    The mirrors must never be adjusted while driving.

-    Extra important information can be received about the traffic’s behavior through looking over one’s shoulders. One can never get this view even looking at the mirrors no matter how well they are positioned.

-    One must make a habit to always look over the shoulders before changing lanes.

-    Although this mirror technique is very beneficial in reducing the problem of blind spots but one cannot totally depend on it for eliminating blind spots. There may be other moving objects like even bicycles, motorcycles and smaller cars that can possibly hide in unexpected areas around one’s car.

About the Author

You might also be interested in learning how to replace a car side mirror and how to replace your car’s rear view mirror

.

can I convert a newtonian telescope to a schmitt-casegrain ?

I have a 10" newtonian mirror in a semi-working home made telescope. Can I send the primary mirror to a lab and have them cut a hole in it to make a schmidt casegrain ? I know I need a special secondary concave mirror, but can they drill a hole in the primary mirror once its coated or do I have to pay for a new coating ?

I think you run a considerable risk of scratching the mirror when the hole is bored. Cassegrain mirrors are usually bored before grinding and polishing. Also, as stork5100 points out, the figure of a Newtonian mirror is wrong for a Schmidt-Cassegrain.

But the bigger difference is that Cassegrain systems are generally based on a short focal ratio primary. You could build a classical Cassegrain based on your Newtonian mirror, but it would probably be f/30 or longer. The primary in a typical SCT is around f/2.

You're also going to have to figure a way to make that corrector plate if you want a Schmidt-Cassegrain. (And the secondary is convex, not concave.)

Secondary Mirror

Telescope Spider

 

Roller Banner Stands: A Great And Versatile Display Solution

Roller banner stands allow you to easily carry around your banner in a rolled up form. At the location, you draw out the stand from a base, unroll the banner and mount it on the pulled out stand. The core components are a tripod or other base, telescopic stand that can be drawn out from the base and extended to the required size and mounting hardware that allows you to set up the banner on the stand.

Easy to Carry

Packed in a nylon bag, the roller banner kits can be carried around to any location you want, such as exhibition grounds, sports stadiums, festival venues and other places where crowds gather. At the location, they are put up as outlined earlier and you have a highly visible banner ad that conveys your promotional message to the gathered crowd.

Different Designs

The banner stands can come in different sizes and with different features. Some come with built-in lighting systems so that the messages will be visible in dark areas and at night. The lighting can also add to the eye-catching capability of the display through the use of novel lighting displays.

Other stands can be connected to electric outlets and operated even more easily through motorized devices, or the display can be controlled digitally, enabling dynamic displays instead of a static copy.

Yet other designs make the whole display, including the stand, superbly impressive. The poster holders might integrate into the display by providing the display with a gold painted border with no gap between the banner and holders, for example. In addition to the aesthetics, the holders can also provide protection being made of steel or sturdy aluminum.

Some banners might come with the display being protected by glass boards, protecting it from rain and sleet, as well as dust and other degrading stuff.

Roller banner stands suited to different budgets are thus available. Typically, the more expensive models make operation easier and the displays more versatile and impressive. The more expensive models can make the messages clearly visible to quite a distance even in dark conditions.

Where to get Your Roller Display Stand

There are many suppliers for the increasingly popular roller display stands. However, not all of them offer a complete package, including a range of equipment as well as incidental services such as designing the display, artwork studio and printing services. When you buy all the components from one source, you are more likely to get a solution where all parts fit neatly together.

Suppliers also differ in the time they need to provide the solution as well as in the promptness and quality of their after-sales service.

Look at your requirements and choose a company that will meet these requirements, and do so in the short time before your deadline without sacrificing quality. Typically, you send your basic requirements, including the preliminary copy to the supplier who will then work on these and come up with an impressive solution.

Roller banner stands deliver a modern solution to your promotional needs. They are convenient, effective and above all, almost instant. They are also reusable, saving you both time and money.

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Chris Farnworth Talks about www.Bannersndisplay.co.uk . Banners N Display Have a wide range of Roller Banner Stands with various options and alternatives so you can easily find what you are looking for. You may freely reprint this article in its entirety, providing you include the authors resource box along with links without no follow tags.

Where are these diffraction spikes from?

Ok I was watching a video on the greatest tennis players of all time and at the very beginning I saw diffractions spikes from the camera. http://www.youtube.com/watch?v=pf9K_kEXw-4&NR=1
I asked a few weeks ago where were the spikes from and learned it was from diffraction from the spider in telescopes. But how can this camera make 6 clean spikes since it is a refraction optical device, and that all optics are symmetric?? you're going to tell me its from the diaphragm, but a diaphragm is almost spherical and could not make such 6 clean spikes...I'm confused.

thanks a lot

Any one of three techniques come to mind.

1) spike filter
2) computer generated
3) Diaphragm

It's pretty easy to create spikes like that. Photographers have been doing that for decades.

From there, software programs can manipulate images on the fly. in this case video. enough is known about how light acts that it can be simulated in a computer.

Ten there is the lens itself, which is never perfect. Lens flares, internal bafflings and the type of aperture can all cause spikes.

Telescope Spider

Spherical Telescope Mirror

 

Wavefront Technology As Applied to Vision Correction - Is it For You?

Lasik surgery is perhaps the most common type of surgery that is performed in the US. Lasik is a type of surgery that changes the shape of the cornea to help correct the vision. Lasik surgery is a common procedure where a laser is guided to correct the cornea. However there are new developments in the Lasik eye surgery procedure and one major development has been the custom Lasik surgery.

Let us understand what custom lasik surgery means here. In the conventional world the Lasik eye surgery is used to correct the vision whereby using the laser the surgeon corrects the cornea. In the custom Lasik surgery the doctor uses the results from the laser to detect the aberrations and then use those results to direct the laser to a correct place on the cornea. In a nutshell, the laser is used for two things one is detecting the aberration and then uses the individual customized results to direct the laser.

Wavefront technology is not very new though it has been only a few years since the Wavefront technology has been used in the eye surgery area. Astronomers used to apply this technology to adjust the optical lenses of their telescopes. There is a reflecting mirror in the telescope which is constantly adjusted based on the information the Wavefront data sends about the deformities or aberration in the atmosphere.

The scenario is something similar in the human vision area where the Wavefront technology is used for doing two things. One is the detection of the aberrations and then other is corrections of the aberrations using this data received while detecting aberrations. Now the data received is different for every individual and hence customized. That is why in the Lasik world this is known as custom Lasik and the normal Lasik surgery is known as conventional Lasik surgery.

The manufactures who make this Wavefront responsive technology available to doctors are only four in the United States. These come with trade names like CustomCornea, CustomVue and Zyoptix. These three are customized Lasik solutions and the last one by the trade name Wave Light Allegretto does not use customized data but uses the data which was derived in the laboratory to guide the laser.

The Wavefront diagnosis is done using light which is sent into the eye using a specific pattern and if there are aberrations then light will come out in a wavy pattern. Then there are higher order aberrations which can only be detected by Wavefront diagnosis. Conventional eye exams can only detect lower order aberration particularly related to cylindrical and spherical aberrations. So make sure to ask you doctor about conventional as well custom Lasik and evaluate your options.

About the Author

The author has a website guiding people looking for rhinoplasty before after affects of nose job.He recommends patients asking the doctor about rhinoplasty before and after results of previous patients to know what they will look like after surgery.

Who sells acrylic spherical concave mirrors with long focal lengths?

I am looking for a 6" or larger spherical concave mirror with a 2 to 4 foot (or more) focal length.

I specified acrylic because I do not need (nor do I want to pay for) a high-quality telescope grade mirror. I just want one of those $25-$50 convex mirrors, but concave instead.

I can find a hundred inexpensive convex mirrors.

I can find a hundred very expensive telescope mirrors.

I can find a FEW concave mirrors, but they all have very short focal lengths. Most bathroom mirrors are like this.

I do

Spherical Telescope Mirror