How do I Dispose of Batteries

If you're like most people, you just toss used batteries into the nearest available trashcan, never giving them a second thought. What you probably didn't realize is that this method can be harmful to the environment. Batteries should be recycled or disposed of in a proper manner. 

Once a battery loses power, remove it immediately from its casing or it may leak. Don't place it in your pocket or purse as this may cause it to rupture. Instead, place the battery in a container or resealable bag (ziplock) until you can dispose of it in the correct manner.

Don't store used batteries together to dispose of in a group. Even though a battery might not be able to run a toy or game anymore, it might still have a small bit of power left. If several batteries bang together, they can emit a charge which can cause them to ignite. Don't mix old and new batteries together in order to get an electronic item to work. The batteries can ignite, rupture or leak, causing damage to you as well as the electronic item.

Since many types of batteries are considered household waste, you should follow proper guidelines for disposal. Your town or city will most likely have a hazardous waste pick-up or drop-off day. Check with the city's website or newsletter to find what guidelines, if any, should be followed for properly disposing of batteries. Most hazardous waste days are noted in the local newspaper as well. 

Many of the regular alkaline batteries are not considered hazardous waste and can be disposed of in the normal household trash. For other batteries such as lithium, mercuric, oxide, nickel-cadmium, nickel metal hydride and silver oxide however, it's best to err on the side of caution and follow your town's battery recycling guidelines. The batteries contain elements that can leak into the ground presenting a hazard to the environment. In most cases, batteries can be brought to your local recycling center at any time, or they can be picked up on your town's designated household waste disposal days. 

Many automotive stores and other places selling batteries will accept batteries for recycling as well. In addition, there are commercial battery disposal organizations which will recycle your batteries for a small fee. 

Most of these places can be found using an internet search or by looking in your local business telephone directory. Never take the lazy route and dispose of batteries in a fire. They'll ignite, explode and possibly cause damage to you or the surrounding area. 

It's worth it to bring your batteries to your nearest battery recycling location. Not only is it safer for you, but it's safer for the world around you.

How do Networks Know How Many People are Watching a TV Program

Television networks clearly want to know what people are watching. A larger audience watching a show translates to being able to charge more money for ad time during a show. Television networks that broadcast shows watched by a huge number of people, such as the Oscars or the Super Bowl, generally profit from getting the highest dollar amount for advertisements aired during their shows. For weekly programs, however, television networks rely on a small sample of the population to determine what shows are the most popular.

In the US and in Canada, the company that tracks what viewers are watching for television networks is the Nielsen Company. They choose a representative sampling of about 5000 viewers who will allow Nielsen to record what programs they watch. This is a fairly small sampling of the US population, but people are chosen based on their ability to represent varied populations. For example Nielsen must a diverse sampling of viewers and some viewers who fall into differing age groups in order to get a representative sample.

This representative sample from Nielsen is then turned into a percentage representing viewership. Thus if 500 people watch Gray’s Anatomy weekly, Nielsen concludes that 10% of television viewers in all households watch the show. Shows are then ranked by numbers of viewers they garner each week.

People who participate in Nielsen Ratings programs are normally given monthly compensation for having their viewing habits tracked. This amount is relatively small, less than 50 US dollars (USD). Some people turn the money around to pay for their cable bills.

Each Nielsen participant is given a small black box, essentially a cable and modem that sends information about what the person or persons in the family are watching. In general, Nielsen only records what is being watched, and it is possible to have two programs in an hour count as “being watched” by television networks. If one watches one program for ten minutes and then switches to another program for ten straight minutes the data collected can become faulty in determining the popularity of programs on television networks.

Nielsen ratings do not always work because the population of representative viewers is so small. Some programs have been quickly axed by television networks for having a tiny viewing audience. However, write-in campaigns from loyal fans of the show can sometimes get a program back on the air. 

With many shows now available on the Internet, the possibilities of tracking viewers have opened up. Television networks can definitely track how many people are willing to pay for, and download a show, and there are many networks that also offer shows for free with limited advertising. The number of downloads can be recorded by television networks and might influence decisions about keeping certain programs airing.

Cable companies might also track a viewer’s habits. For example, a cable company knows how many pay per view movies a household orders. Surveys of what people are watching may also help determine the popularity of a given show.

What are Lasers Used for

Lasers are used in practically every major industry, from medicine and computers, to entertainment and construction. A power rating, usually in watts, determines the strength of the laser. Some lasers can cut through metal, while others merely read tiny bits of information without damaging the surface. Basically, the application of lasers can be divided into marking, etching, and cutting, or reading and scanning.

In the medical industry, carbon dioxide lasers are used in many types of surgery because they are more precise and sensitive than scalpels. Lasers remove tattoos without needing skin grafts, as well as painlessly clearing rot out of teeth. These less invasive lasers result in faster recuperation from surgeries such as removing certain tumors and correcting vision by reforming the eyeball lens. Damage to surrounding tissue, as well as bleeding, has been reduced by incorporating lasers.

Many common home or office devices house lasers as an intrinsic part of their performance. CD, DVD and Blu-Ray players use lasers to read the audio and video information on the disc, the way a needle used to read the groove of a record. CD, DVD and Blu-Ray recorders have stronger lasers that can burn the information onto the surface of the disc, either temporarily or permanently. Laser printers also utilize lasers to change a surface, in this case paper, to display text and graphics. Even at the grocery store, lasers scan the barcode on your packages to tell the computerized register what you're buying and how much it costs.

Lasers of the appropriate strength can etch surfaces from plastic to rock. Some companies inscribe a minute identification number on diamonds to keep track of them. Tombstones made of granite or limestone are carved with powerful lasers. Numerous metal pieces can be precisely cut out, drilled, and welded together to make a finished product using lasers capable of melting metal.

Even though the first laser was made in a laboratory back in 1960, it took several decades to apply this tool to various technologies. Now, lasers are indispensable to our daily lives. Visible lasers have even replaced strings, levels, and stakes in surveying equipment. Everyone should be treated to a laser show inside a planetarium, where colored lasers of all widths simulate the night sky.

What Is an Elmo™ Projector

An Elmo™ projector is a document camera and projection system that is commonly used as a descriptive name for all such systems, regardless of who manufactures them. This is not a correct use of the term and many companies fear when a situation like this develops that they could actually lose the value of their name. In most cases, if the brand is unknown, using the term document camera or document projector instead of Elmo™ projector is advisable.

The main purpose of an Elmo™ projector is to display documents and other objects that are not translucent -- in other words, documents that are not made with transparencies. These documents require a video camera and projection lens in order to work properly. The Elmo™ camera is usually digital. However, they are able to display more than just documents. In many cases, they can be used to display three-dimensional objects as well, though they will be rendered in two dimensions on the screen.

The thought behind the Elmo&trade projector is similar to that of the overhead projector, which came into widespread use during the late 1950s and continued through the 1990s. Such projectors were useful in making materials available to a wide audience in a classroom or group setting, but could only display documents put on transparent material. While duplication to transparencies is easily done, it required an additional step. Further, three-dimensional objects could not be displayed. They would instead be rendered as a black shadow in the area where they were blocking light from passing through.

The document projector changes all of those limitations. In fact, it is not only possible to display documents and objects on an Elmo™ projector, it is possible to even display moving pictures, such as movies. However, this is, by no means the most effective way of displaying such media. The camera used for a document projector does not operate with as many frames per second as standard video cameras. Thus, any movement would appear jumpy. That is one reason they are often called Elmo™ document cameras. It is understood that motion is not important in displaying documents.

Likewise, when looking at three-dimensional objects with Elmo™ document cameras, they should be kept still, or moved very slowly. Often, this is not a problem. If another side of the object needs displayed, it can simply be moved to face the camera. In such cases, the motion is not important and is only used to facilitate the change in the point of view.

Is it Possible to Send a Text Message to a Landline Telephone

As counterintuitive as it may sound, it is possible for certain cellular phone customers to send a text message to a landline. The recipient of such a text message does not need a modified telephone, however. The text message is automatically converted to an automated voice message through "text to voice" technology. All the recipient must do is listen to the message and respond with a recorded voice message of his or her own.

When a cellular phone customer sends a text message to a landline, he or she must first compose the message using a Short Message Service (SMS) format and then input the ten digit phone number of the recipient's landline phone. The cellular phone service provider will attempt to send the text message to a landline at least three times. If the recipient answers the phone, he or she should hear the automated voice message. If the landline phone is not answered, the message may go to voice mail or an answering machine.

Depending on the cellular provider, customers who have subscribed to the SMS service can send a text message to a landline anywhere in the United States, its territories, and possibly Canada. The text to voice program does not require the recipient to install any special equipment or subscribe to a cellular phone service. The sender usually receives a confirmation message stating that the text message has been successfully delivered to the landline.

While it is possible to send a text message to a landline, it is not generally possible to send a text message from a landline to a cellular phone. The recipient of a text message can sometimes choose from a menu of possible responses and send a voice message, but this voice message will not be converted to text on the cellular phone side.

Standard texting and phone call rates apply when sending a text message to a landline phone, and the phone number must be a recognized landline, not another cellular phone.

What Is Airplane Mode on a Cell Phone

Airplane mode is a setting on many cellphones which disables their wireless communication abilities, theoretically making them approved for use on aircraft. While in airplane mode, a phone cannot send or receive phone calls, text messages, picture messages, or video messages, and the user may not browse the Internet on the phone or use Bluetooth® devices with it. However, functions like music players, games, calendars, and so forth can continue to be used.

The idea behind airplane mode is that many people wish to continue using their cell phones on planes to do things like listen to music and check appointments, but the use of cell phones on planes is banned due to the fact that their signals could cause interference. Airplane mode allows cell phone users to circumvent the ban, ensuring that their phones are safe to use on aircraft while the plane is in flight; electronic devices must be turned off for takeoff and landing.

There are two reasons why people are not allowed to use cell phones on aircraft, although the rules against cell phone usage may change at some point. The first reason is that the radio signals emitted by phones could interfere with the communications and guidance systems on the aircraft, which could potentially be very dangerous. In addition, cell phone networks on the ground cannot cope with cell phones being used on planes, because planes travel very fast and at high altitude, so a phone on a plane could confuse a network on the ground.

If a phone offers an airplane mode setting, the user's manual usually clearly shows how to turn airplane mode off and on, and typically it can also be found through the phone's menu. When airplane mode is activated, a small icon often shows up on the screen of the phone to indicate this. In some cases, the user may have to use a password to activate and turn off airplane mode, to ensure that it is not accidentally switched on and off.

Although airplane mode technically makes a phone legal to use on an aircraft, some airlines request that passengers turn their cellphones off anyway, or a flight attendant who is not familiar with the technology may ask you to turn your phone off. Sometimes, explaining that you are using airplane mode is sufficient, and the flight attendant will allow you to leave your phone on, but in other cases, you may be asked to turn it off. Although this may seem unreasonable, it is better to comply; in the wake of the 11 September 2001 terrorist attacks in the United States, airlines are entitled to remove passengers from flights if they fail to comply with requests the airline terms “reasonable.”

What is HSDPA

HSDPA, short for High-Speed Downlink Packet Access, is a new protocol for mobile telephone data transmission. It is known as a 3.5G (G stands for generation) technology. Essentially, the standard will provide download speeds on a mobile phone equivalent to an ADSL (Asymmetric Digital Subscriber Line) line in a home, removing any limitations placed on the use of your phone by a slow connection. It is an evolution and improvement on W-CDMA, or Wideband Code Division Multiple Access, a 3G protocol. 

HSDPA improves the data transfer rate by a factor of at least five over W-CDMA. HSDPA can achieve theoretical data transmission speeds of 8-10 Mbps (megabits per second). Though any data can be transmitted, applications with high data demands such as video and streaming music are the focus of HSDPA.

HSDPA improves on W-CDMA by using different techniques for modulation and coding. It creates a new channel within W-CDMA called HS-DSCH, or high-speed downlink shared channel. That channel performs differently than other channels and allows for faster downlink speeds. It is important to note that the channel is only used for downlink. That means that data is sent from the source to the phone. It isn't possible to send data from the phone to a source using HSDPA. The channel is shared between all users which lets the radio signals to be used most effectively for the fastest downloads.

The widespread availability of HSDPA may take a while to be realized, or it may never be achieved. Most countries did not have a widespread 3G network in place as of the end of 2005. Many mobile telecommunications providers are working quickly to deploy 3G networks which can be upgraded to 3.5G when the market demand exists. Other providers tested HSDPA through 2005 and are rolling out the service in mid to late 2006. Early deployments of the service will be at speeds much lower than the theoretically possible rates. Early service will be at 1.8 Mbps, with upgrades to 3.6Mbps as devices are made available that can handle that increased speed.

The long-term acceptance and success of HSDPA is unclear, because it is not the only alternative for high speed data transmission. Standards like CDMA2000 1xEV-DO and WiMax are other potential high speed standards. Since HSDPA is an extension of W-CDMA, it is unlikely to succeed in locations where W-CDMA has not been deployed. Therefore, the eventual success of HSDPA as a 3.5G standard will first depend upon the success of W-CDMA as a 3G standard.