A Word About Wifi or Wi-fi Technology

WiFi is the other name for wireless internet or wireless network, this name is mostly used by none technical users who just knows how to access internet wirelessly, they know pretty much nothing beyond that. WiFi is basically short form for wireless fidelity. However many advance users are not well aware of this terminology either, it is ,more known with a name of Wifi. WiFi term is written in many ways which are, Wifi, WiFi, WIFI, Wi-Fi fiwi etc.

Wi-Fi was introduced by Wi-Fi alliance in 1985 it was the time when it was not used as commercially but were just set to certain organizations for testing purposes. Wi-Fi Alliance is pioneer in developing WiFi technology and all the hardware associated with Wifi is mostly certified by Wifi Alliance compliance. Wifi later developed properly and than eventually lunched for public use in USA in 90’s, gradually wifi become standards for most of the computer communications in countless organizations around the world.

Wifi uses all the networks referring to any type of 802.11 network standards which is set by IEEE. IEEE is short form of Institute of electric and electronic engineering. There are lots of enhancements made in standards of 802.11 and 802.11a, 802.11b and other dual networks. The latest standard of 802.11 family is 802.11y. Other known standards are 802.16, these are the standards for upcoming technology known to be WiMax. There is one more known set of standards for Ethernet it is known to be IEEE 802.3.

Growth of Wifi networks is still on going world wide this huge growth raises security issues. Wifi is the most widely used network world wide and many organizations transfer their sensitive data using Wireless networks. Increased use of Wireless network increases potentially risks of the security of the users or organization. Wireless network carries data of every type, that can be normal data in bits of information or it can encrypted or even highly sensitive. WiFi security mechanism insures the certain level of data integrity and confidentiality just as wired network provides. However if proper security measures are not adopted properly intruders can attack the network and can cause major damage to not only network but privacy of users also.

There was a time when cables were used to network many computers together. Hardware like routers, hubs, switches etc were required for communication between computers, but Wifi brought high tech change in communication of computers by providing wireless connectivity features. It just keeps things very simple without much hassle and networks can be made far more easily. No wires are required. Wireless network keeps environment very neat and clean. There are many other features of Wireless LANs for example high speed connectivity. Wifi provides high speed connectivity and faster communication where cables are not feasible to install for example in remote areas. The list of the Wifi features is long some other major features included Site survey, enterprise grade equipment, Scalable systems, VPN Compatibility, flexible authentication methods, Guest satisfaction, End user mobility and easy access through Hotspots.

WiFi supports two different types of modes; they are known to be infrastructure and the other one is ad hoc. In Ad hoc Wireless connections can be made without central device called router or access point. Most network administrators prefer ad hoc over infrastructure mode. Ad hoc how ever have issues also. Wifi devices connected using Ad hoc mode offers less security against unauthorized users. Ad hoc mode configured devices cannot disable SSID broadcast in contrast to infrastructure mode, this brings hackers into play, and using ad hoc mode it is not very difficult to prevail into the wireless network. There are two major differences between these two modes that is the rate at which they transfer data. Wife network standard 802.11g requires Ad hoc mode of communication to support 11Mbps bandwidth in contrast to it 54Mbps data transfer is supported using infrastructure mode. Hence Ad hoc mode is considered much slower than Infrastructure mode.

Wireless based networks are increasing every where; every organization is installing it if it was not using it before. Some cities have actually provided the entire city a wifi and turn the city into hotspot, big example in front of us is Chicago. Chicago have installed huge transmitter in shape of big size dish of Wifi which broadcast Wireless LAN radio signals through out the city. It provides high speed internet connectivity very cheaply. Laptops, desktop computers, PDAs and other Wireless LAN card installed devices can access the network and get high speed connectivity on move. WiFi users increasing day by day therefore its hardware manufacturers are manufacturing the products on huge scale. These products are easily available in market with reasonable cost. Laptops, PDAs, mother boards of latest desktop computer are mostly come with build in wireless LAN cards. If it is not installed already in your laptop one can buy PCMCI slot wifi card to install for accessing wireless network. Wifi PCI cards are also widely available in market. Now USB wifi are also available for short range but still works good.

Intelligent routers are available in market which works to connect different devices to wireless network. These routers can be configured with or without PC. All is required to plug internet cable in Ethernet or USB port to router’s appropriate port. When internet is available to routers it can be configured using its control panel using IP 192.168.1.1. That’s where we can enable SSID broadcasting or disable it and perform other functions. PCs can also be attached to routers for more advance management which routers can not performs. PCs are mostly required to be used where network is huge and keeping and maintaining its integrity and stability is very important.

In this modern era every one wants every thing wireless, Wifi belongs to wireless technology family. There are so many other wireless technologies which have evolved around the time and Wifi is now taken for granted and world is now talking about much advanced and enhanced wireless network known to be WiMax. WiMax beats Wifi technology on many bases which includes Speed at which data rate is transferred, range with which connection is made and so much more. Now we have to see in how much time WiMax will take over WiFi, and which technology will eventually take over WiMax. One thing is for sure latest technologies in wireless technology will keep coming and will keep getting over looked by new ones.

Mobile Phone Network

The breakthrough in wireless technology has arrived with the introduction of the Mobile Phone. The need for fast and effective communication sparing no time loss is what has brought the birth of the Mobile Phone. The mobile phone network strives to promote the mobile into the home of every individual. The mobile phone network reaches out to all corners of the world. There is continuous progress to get the wireless connection in even the remotest areas for the signal is something weak or the wireless is unable to make connection with the mobile phone. But ninety percent of the wireless network works like a charm. The mobile phone network continues to work on providing the signals in the remote areas.


The Mobile Phone Network and the Internet

You can browse the Internet for the various mobile phone networks available in your country. There are many networks that provide national and international wireless connection with your mobile. The mobile phone network offers deals and good tariff rates and plans to suit each customer. There are mobile phone brands that have a tie-up with the mobile phone network and you can select the network and the mobile brand in accordance with the offer by the mobile phone dealers. There are many mobile phone networks and mobile phones that interact and this could leave you confused but at the internet station you can take your time to study the various features and deal of phones and mobile phone networks before you decide on the best mobile phone network for you.


The Mobile Phone Network and the Mobile Phone

The mobile phone network works in collaboration with the mobile phone. There are many kinds of mobile phone networks that are available in almost every country. Some of the main networks are O2, T Mobile, 3G, Vodafone and Orange among others. The leading mobile phone networks provide many exciting deals for the customers and likewise promote the brand of the mobile as provided by the mobile phone manufacturers.

Inkjet Cartridges Overview

Inkjet cartridges came into light in about 1980, to print images on blank paper. These cartridges can be slightly more expensive when compared to other types of ink cartridges, because they have the capability to be refilled.

Inkjet cartridges are used to visualize images or any print transaction, and other activities related to printers. These inkjet cartridges work along with inkjet printers. By using these cartridges, the inkjet printer places small droplets onto blank paper via nozzles to develop any image or text. The amount of the droplet depends on the printer driver software that is systematized to place the droplets. The cartridge has various colors as in liquid form to develop a colorful/black and white image on printable paper.

Inkjet printers are capable of printing stickers, labels, posters, and documents, etc by using inkjet cartridges. Nowadays, these printers are also being used to develop attractive images on shoes, T-shirts, etc.

The drops of ink that come out from the inkjet cartridge to create images are generally between 50 to 60 microns. These cartridges come in different varieties, in various brands along with different options. The cost of these cartridges depends on their qualities and brands.

Since there are so many works which can be performed by inkjet printers, it is necessary to have complete information before purchasing the right inkjet cartridges.

The inkjet cartridge should be made by appropriate materials that not only increase the productivity level, but also offer better and quality prints. Therefore, never purchase local or average inkjet cartridges, because such cartridges may create problems for the nozzles of the printer. A well-suited and branded inkjet cartridge, especially ISO standard, can be more efficient and better than other cartridges that are available in the market.

Mostly, inkjet cartridges come in their individual sizes, which are designed to fit with a particular printer only. Any typical size of cartridge may cause damage to the printer's nozzles. Always purchase an inkjet cartridge with its warranty (minimum one year). Most printers come with a warranty period, but in some cases the warranty can be canceled if the cartridges that are used in it are made by a different manufacturer. So, for the continuity of the warranty, it is essential that both the printer and the cartridges are designed by the same manufacturer.

Although online shopping is the easiest way to buy any product without going to the shops, always be careful when you are buying inkjet cartridges online. If you choose to buy online, be sure about the credibility of the site that you are buying from, so that you don't purchase low quality cartridges.

It is best to compare the prices of various inkjet cartridges at different shops, as there may be a high difference between the prices of the same product in two different stores.

The importance of printers cannot be denied, but this does not mean that you should compromise on the quality. You may take a little bit more time in comparing and then purchasing an inkjet cartridge, but make sure that you are opting for the best one in the market.

How Do Inkjet Printers Work

The printers utilizing inkjet technology were first introduced in the late 1980s and since then have gained much popularity while growing in performance and dropping in price. They are the most common type of computer printers for the general consumer due to their low cost, high quality of output, capability of printing in vivid color, and ease of use. Each printer which works on inkjet technology places extremely small droplets of ink onto paper to create a text or an image.

In the personal and small business computer market, inkjet printers currently predominate. Inkjets are usually inexpensive, quiet, reasonably fast, and many models can produce high quality output. Like most modern technologies, the present-day inkjet is built on the progress made by many earlier versions. Among many contributors, Epson, Hewlett-Packard and Canon can claim a substantial share of credit for the development of the modern inkjet technology. In the worldwide consumer market, four manufacturers account for the majority of inkjet printer sales: Canon, Hewlett-Packard, Epson, and Lexmark.

The typical inkjet printer usually includes inkjet printhead assembly, paper feed assembly, power supply, control circuitry and interface ports.

The inkjet printhead assembly contains several components. One of them is the printhead which is the core of the inkjet printer and contains a series of nozzles that are used to spray drops of ink. Another printhead component is the inkjet cartridge or inkjet tank. Depending on the manufacturer and model of the printer, ink cartridges come in various combinations, such as separate black and color cartridges, color and black in a single cartridge or even a cartridge for each ink color. The cartridges of some inkjet printers include the print head itself. The printhead along with the inkjet cartridge/s are moved back and forth across the paper by device called a stepper motor using a special belt. Some printers have an additional stepper motor to park the print head assembly when the printer is not in use which means that the print head assembly is restricted from accidentally moving. The print head assembly uses a stabilizer bar to ensure that movement is precise and controlled.

One of the paper feed assembly components is the paper tray or/and paper feeder. Most inkjet printers have a tray that the paper is loaded into. The feeder typically snaps open at an angle on the back of the printer, allowing the paper to be placed in it. Feeders generally do not hold as much paper as a traditional paper tray. A set of rollers pull the paper in from the tray or feeder and advance the paper when the print head assembly is ready for another pass after which another step motor powers the rollers to move the paper in the exact increment needed to ensure a continuous image is printed.

While earlier printers often had an external transformer, most printers sold today use a standard power supply that is incorporated into the printer itself.

A small but sophisticated amount of circuitry is built into the printer to control all the mechanical aspects of operation, as well as decode the information sent to the printer from the computer. It is connected to the computer by a cable through the interface port. The interface port can be either parallel port, USB port or SCSI port. The parallel port is still used by many printers, but most newer printers use the USB port. A few printers connect using a serial port or small computer system interface (SCSI) port.

Different types of inkjet printers exist based on the method they use to deliver the droplets of ink. There are three main inkjet technologies currently used by printer manufacturers. The thermal bubble technology used by manufacturers such as Canon and Hewlett Packard is commonly referred to as bubble jet. In a thermal inkjet printer, tiny resistors create heat, and this heat vaporizes ink to create a bubble. As the bubble expands, some of the ink is pushed out of a nozzle onto the paper. When the bubble collapses, a vacuum is created. This pulls more ink into the print head from the cartridge. A typical bubble jet print head has 300 or 600 tiny nozzles, and all of them can fire a droplet simultaneously. Thermal inkjet technology is used almost exclusively in the consumer inkjet printer market. The ink used is usually water-based, pigment-based or dye-based but the print head is produced usually at less cost than other ink jet technologies.

Contrary to the bubble jet technology, the piezoelectric technology, patented by Epson, uses piezo crystals. A crystal is located at the back of the ink reservoir of each nozzle. The crystal receives a tiny electric charge that causes it to vibrate. When the crystal vibrates inward, it forces a tiny amount of ink out of the nozzle. When it vibrates out, it pulls some more ink into the reservoir to replace the ink sprayed out.

The continuous inkjet method is used commercially for marking and coding of products and packages. The first patent on the idea is from 1867, by William Thomson. The first commercial model was introduced in 1951 by Siemens. In continuous inkjet technology, a high-pressure pump directs liquid ink from a reservoir through a microscopic nozzle, creating a continuous stream of ink droplets. A piezoelectric crystal causes the stream of liquid to break into droplets at regular intervals. The ink droplets are subjected to an electrostatic field created by a charging electrode as they form. The field is varied according to the degree of drop deflection desired. This results in a controlled, variable electrostatic charge on each droplet. Charged droplets are separated by one or more uncharged “guard droplets” to minimize electrostatic repulsion between neighboring droplets. The charged droplets are then directed (deflected) to the receptor material to be printed by electrostatic deflection plates, or are allowed to continue on undeflected to a collection gutter for reuse. Continuous inkjet is one of the oldest inkjet technologies in use and is fairly mature. One of its advantages is the very high velocity (~50 m/s) of the ink droplets, which allows the ink drops to be thrown a long distance to the target. Another advantage is freedom from nozzle clogging as the jet is always in use

When printing is started, the software application sends the data to be printed to the printer driver which translates the data into a format that the printer can understand and checks to see that the printer is online and available to print. The data is sent by the driver from the computer to the printer via the connection interface. The printer receives the data from the computer. It stores a certain amount of data in a buffer. The buffer can range from 512 KB random access memory (RAM) to 16 MB RAM, depending on the printer model. Buffers are useful because they allow the computer to finish with the printing process quickly, instead of having to wait for the actual page to print. If the inkjet printer has been idle for a period of time, it will normally go through a short cleaning cycle to make sure that the print heads are clean. Once the cleaning cycle is complete, the inkjet printer is ready to begin printing. The control circuitry activates the paper feed stepper motor. This engages the rollers, which feed a sheet of paper from the paper tray / feeder into the printer. A small trigger mechanism in the tray / feeder is depressed when there is paper in the tray or feeder. If the trigger is not depressed, the inkjet printer lights up the "Out of Paper" LED and sends an alert to the computer. Once the paper is fed into the inkjet printer and positioned at the start of the page, the print head stepper motor uses the belt to move the print head assembly across the page. The motor pauses for the merest fraction of a second each time that the print head sprays dots of ink on the page and then moves a tiny bit before stopping again. This stepping happens so fast that it seems like a continuous motion. Multiple dots are made at each stop. It sprays the CMYK (cyan / magenta / yellow / black) colors in precise amounts to make any other color imaginable. At the end of each complete pass, the paper feed stepper motor advances the paper a fraction of an inch. Depending on the inkjet printer model, the print head is reset to the beginning side of the page, or, in most cases, simply reverses direction and begins to move back across the page as it prints. This process continues until the page is printed. The time it takes to print a page can vary widely from printer to printer. It will also vary based on the complexity of the page and size of any images on the page. Once the printing is complete, the print heads are parked. The paper feed stepper motor spins the rollers to finish pushing the completed page into the output tray. Most inkjet printers today use inkjet inks that are very fast-drying, so that you can immediately pick up the sheet without smudging it.

Compared to earlier consumer-oriented printers, inkjet printers have a number of advantages. They are quieter in operation than impact dot matrix printers or daisywheel printers. They can print finer, smoother details through higher printhead resolution, and many inkjet printers with photorealistic-quality color printing are widely available. In comparison to more expensive technologies like thermal wax, dye sublimations, and laser printers, the inkjet printers have the advantage of practically no warm-up time and lower cost per page (except when compared to laser printers).

The disadvantages of the inkjet printers include flimsy print heads (prone to clogging) and expensive inkjet cartridges. This typically leads value-minded consumers to consider laser printers for medium-to-high volume printer applications. Other disadvantages include ink bleeding, where ink is carried sideways away from the desired location by the capillary effect; the result is a muddy appearance on some types of paper. Most inkjet printer manufacturers also sell special clay-treated paper designed to reduce bleeding. Because the ink used in most inkjet cartridges and ink tanks is water-soluble, care must be taken with inkjet-printed documents to avoid even the smallest drop of water, which can cause severe "blurring" or "running."

Besides the well known small inkjet printers for home and office, there is a market for professional inkjet printers; some being for page-width format printing, and most being for wide format printing. "Page-width format" means that the print width ranges from about 8.5" to 37". "Wide format" means that these are inkjet printers ranging in print width from 24" up to 15'. The application of the page-width inkjet printers is for printing high-volume business communications that have a lesser need for flashy layout and color. Particularly with the addition of variable data technologies, the page-width inkjet printers are important in billing, tagging, and individualized catalogs and newspapers. The application of most of the wide format inkjet printers is for printing advertising graphics; a minor application is printing of designs by architects or engineers.

Electro Magnetic Fields and the Nature Rythms of the Earth

The electromagnetic fields are present everywhere. They can be caused by natural means or by artificial methods. The natural methods are those produced by the sun, earth, moon and finally our body. The artificial fields are produced by all electrical appliances and cell phones. Radio communication also tends to increase the electromagnetic field. Apparently mobile phone conforms to both of these. They are a major producer of electromagnetic field and are present very close to humans. 

The body has a natural rhythm tuned to that of earth's electromagnetic field. This can be felt during power failures. The body tends to relax once the source of electricity, around it, is cut off. There is a sense of calmness and serenity in the absence of an electrical appliance. This directly points to the fact that the body is not at ease to the presence of the electrical gadgets. However, life is impossible without electrical appliances. They must be avoided as much as possible in order to protect the health of the body. Similarly, frequent headaches are common to people who are engaged with their cell phones most of the time. 

The sun is a constant source of electromagnetic waves. The moon and the space surrounding the earth tend to modify the electromagnetic field of the earth. This causes the field of the earth to be at a constant change throughout the year. The surface and the ionosphere cause the electromagnetic field to bounce from one to another thereby causing pulse of about 0.1 to thirty cycles per second. 

The average pulse is that of ten cycles per second and it is referred to as the Rhythm of the Earth. The body has learned to adapt to this invisible electromagnetic field. A very common example is that of female menstruation cycle. It has been found that a particular pineal gland responds in accordance to that of earth's electromagnetic field. It controls the moods and sleeping habits of the body. The immunity of the body depends on this gland as well. The brain waves are those produced by the brain for communicating with other organs through the nervous system. 

Coincidentally, the relaxed brain generates around 10 cycles per second similar to that of our earth. The waves are reduced during sleep and are escalated when under pressure or excitement. The gland secretes a fluid called melatonin which increases the immunity of the body. Any change in this melatonin would cause severe damage to the body in the form of cancers and tumors. 

The body is suited to an electromagnetic field of about 30 cycles per second. However, the external disturbance of over 50 cycles would cause discomfort to both the brain and the body. This is capable of causing several diseases over the period. The tests of these electromagnetic fields over lab animals have proved that they are harmful for the brain and blood.

They also affect the normal functioning of the hormones and also cause cancer, tumor and miscarriages. Several researches and tests have concluded that children living near huge source of electromagnetic fields are prone to disease like leukemia and nerve or lymph cancer. Similar cases have been reported in the case of women who have had miscarriages, birth defects and cancers. 

The mobile phones produce about a million cycles per second. They are a source of death for sure. The brain damage reported because of cell phones is increasing every day. People accustomed to cell phone suffer from mood variations and stress. The phones directly affect the pineal glands because of the proximity to the brain. 

Mobile phones cannot be disposed off entirely because of these harmful effects. However, steps can be taken to prevent these diseases from becoming a regular pattern. The usage of mobile phones should be decreased at any cost. Researches should be made to make an alternative source of communication which would not be this dangerous

Injection Molding-How Plastic is Molded

Plastic has, quite literally, become the cornerstone of our society. We make so many things from plastic that it is hard to imagine what our lives would be like if it was never invented. With so many of our everyday products being made of plastic, it is easy to understand why plastic injection molding is such a huge industry.

Approximately 30% of all plastic products are produced using an injection molding process. Of this 30%, a large amount of these products are produced by using custom injection molding technology. Six steps are involved in the injection molding process, after the prototype has been made and approved.

The first step to the injection molding process is the clamping of the mold. This clamping unit is one of three standard parts of the injection machine. They are the mold, the clamping unit and the injection unit. The clamp is what actually holds the mold while the melted plastic is being injected, the mold is held under pressure while the injected plastic is cooling.

Next is the actual injection of the melted plastic. The plastic usually begins this process as pellets that are put into a large hopper. The pellets are then fed to a cylinder; here they are heated until they become molten plastic that is easily forced into the mold. The plastic stays in the mold, where it is being clamped under pressure until it cools.

The next couple of steps consist of the dwelling phase, which is basically making sure that all of the cavities of the mold are filled with the melted plastic. After the dwelling phase, the cooling process begins and continues until the plastic becomes solid inside the form. Finally, the mold is opened and the newly formed plastic part is ejected from its mold. The part is cleaned of any extra plastic from the mold.

As with any process, there are advantages and disadvantages associated with plastic injection molding. The advantages outweigh the disadvantages for most companies; they include being able to keep up high levels of production, being able to replicate a high tolerance level in the products being produced, and lower costs for labor as the bulk of the work is done by machine. Plastic injection molding also has the added benefit of lower scrap costs because the mold is so precisely made.

However, the disadvantages can be a deal breaker for smaller companies that would like to utilize plastic injection molding as a way to produce parts. These disadvantages are, that they equipment needed is expensive, therefore, increasing operating costs.

Thankfully, for these smaller companies, there are businesses that specialize in custom plastic injection molding. They will make a mock up mold to the exact specifications, run it through the complete process and present the completed piece along with an estimate to complete the job to the customer.