Theory and construction
A railgun consists of two parallel metal rails (hence the name) connected to an electrical power supply. When a conductive projectile is inserted between the rails (at the end connected to the power supply), it completes the circuit. Electrons flow from the negative terminal of the power supply up the negative rail, across the projectile, and down the positive rail, back to the power supply.

This current makes the railgun behave as an electromagnet, creating a powerful magnetic field in the region of the rails up to the position of the projectile. In accordance with the right-hand rule, the magnetic field circulates around each conductor. Since the current is in opposite direction along each rail, the net magnetic field between the rails (B) is directed vertically. In combination with the current (I) across the projectile, this produces a Lorentz force which accelerates the projectile along the rails. There are also forces acting on the rails attempting to push them apart, but since the rails are mounted firmly, they cannot move. The projectile slides up the rails away from the power supply.

A very large power supply providing, on the order of, one million amperes of current will create a tremendous force on the projectile, accelerating it to a speed of many kilometres per second (km/s). 20 km/s has been achieved with small projectiles explosively injected into the railgun. Although these speeds are possible theoretically, the heat generated from the propulsion of the object is enough to erode the rails rapidly. Such a railgun would require frequent replacement of the rails, or to use a heat resistant material that would be conductive enough to produce the same effect.
Railguns as weapons

Railguns are being researched as weapons with projectiles that do not contain explosives, but are given extremely great velocities: 3,500 m/s (11,500 ft/s, approximately Mach 10 at sea level) or more (for comparison, the M16 rifle has a muzzle speed of 930 m/s, or 3,050 ft/s), which would make their kinetic energy equal or superior to the energy yield of an explosive-filled shell of greater mass. This would allow more ammunition to be carried and eliminate the hazards of carrying explosives in a tank or naval weapons platform. Also, by firing at greater velocities railguns have greater range, less bullet drop and less wind drift, bypassing the inherent cost and physical limitations of conventional firearms–"the limits of gas expansion prohibit launching an unassisted projectile to velocities greater than about 1.5 km/s and ranges of more than 50 miles [80 km] from a practical conventional gun system."

If it were possible to apply the technology as a rapid-fire automatic weapon, a railgun would have further advantages of increased rate of fire. The feed mechanisms of a conventional firearm must move to accommodate the propellant charge as well as the ammunition round, while a railgun would only need to accommodate the projectile. Furthermore, a railgun would not have to extract a spent cartridge case from the breech, meaning that a fresh round could be cycled almost immediately after the previous round has been shot.
Tests
Naval Surface Warfare Center test firing in January 2008, leaving a plume of plasma behind the projectile.

Full-scale models have been built and fired, including a very successful 90 mm bore, 9 MJ kinetic energy gun developed by the US DARPA. Rail and insulator wear problems still need to be solved before railguns can start to replace conventional weapons. Probably the oldest consistently successful system was built by the UK's Defence Research Agency at Dundrennan Range in Kirkcudbright, Scotland. This system has now been operational for over 10 years at an associated flight range for internal, intermediate, external and terminal ballistics, and achieved several mass and velocity records.[

The Yugoslavian MTI (MTI - Military - technology institute) developed, within a project named EDO-0, a rail gun with 7 kJ kinetic energy, in 1985. In 1987 a successor was created, project EDO-1, that used projectile with a mass of 0.7 g and achieved speeds of 3,000 m/s, and with a mass of 1.1 g reached speeds of 2,400 m/s. It used a track length of 0.7 m. According to those working on it, with other modifications it was able to achieve a speed of 4,500 m/s. The aim was to achieve projectile speed of 7,000 m/s. At the time, it was considered a military secret.

The United States military is funding railgun experiments. At the University of Texas at Austin Institute for Advanced Technology, military railguns capable of delivering tungsten armor piercing bullets with kinetic energies of nine megajoules have been developed. MJ is enough energy to deliver 2 kg of projectile at 3 km/s–at that velocity a rod of tungsten or another dense metal could easily penetrate a tank, and potentially pass through it.

The United States Naval Surface Warfare Center Dahlgren Division demonstrated an 8 MJ rail gun firing 3.2 kg projectiles in October 2006 as a prototype of a 64 MJ weapon to be deployed aboard Navy warships. The main problem the Navy has had with implementing a railgun cannon system is that the guns wear out due to the immense heat produced by firing. Such weapons are expected to be powerful enough to do a little more damage than a BGM-109 Tomahawk missile at a fraction of the projectile cost. Since then, BAE Systems has delivered a 32 MJ prototype to the Navy.

Due to the very high muzzle velocity that can be attained with railguns, there is interest in using them to shoot high-speed missiles.[citation needed]

On January 31, 2008 the US Navy tested a railgun that fired a shell at 10.64 MJ with a muzzle velocity of 2,520 m/s. Its expected performance is a muzzle velocity over 5,800 m/s, accurate enough to hit a 5 meter target over 200 nautical miles (370.4 km) away while firing at 10 shots per minute. The power was provided by a new 9-megajoule (MJ) prototype capacitor bank using solid-state switches and high-energy-density capacitors delivered in 2007 and an older 32-MJ pulse power system from the US Army’s Green Farm Electric Gun Research and Development Facility developed in the late 1980’s that was previously refurbished by General Atomics Electromagnetic Systems (EMS) Division. It is expected to be ready between 2020 to 2025

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If you like the features of the iPhone but you don't consider yourself a Mac person then you will be happy to know that Acer came up with one of the best alternatives to date which is said to rival the features and look of the iPhone, such handheld device is called the Acer Liquid A1 Smartphone and it is the device that we are going to be reviewing today.

Acer Liquid A1 Box Contents

This smartphone comes with a wall charger with various socket inserts, a USB cable to link your handheld device to your computer, a 2 GB microSD card, a screen protector, a user guide as well as all the software required to synchronize your phone with your computer. Right of the bat we must say that having a 2 GB microSD card is a nice addition to this box set.

Look and feel

The Acer liquid A1 is somewhat similar to the iPhone in the sense that it also features a touchscreen and its overall design emulates that of the iPhone however the A1 features a beautiful black finish that is not found on the iPhone. If you like sharp graphics then you will be pleased to know that this smartphone features a 3.5 inch touch sensitive WVGA which makes all the objects on the screen look really sharp and clear.

Features and specs

As we already said the A1 features a 3.5 inch touch sensitive WVGA screen, at the very top it has LEDs will let you know whenever you have a message without having to look at the screen of the phone. On the right hand side you will find the volume controls as well as a shortcut to the camera which by the way is five megapixels in resolution. This phone also uses a Lithium-ion 1300 mAh battery which provides plenty of talk time, a Snapdragon processor that has been under clocked to work at around 768 MHz and increases the responsiveness of the handset, WiFi and Bluetooth connectivity along with GPS capabilities and to top it all it supports QuadBand (GSM/GPRS/EDGE and triband HSDPA). If you are a power user then you will but you know that this phone has 512 MB of ROM (read only memory) and 256 MB of RAM which can be expanded with the included microSD card.

This phone also features four easy-to-use navigation buttons which are a pretty nice addition for those users who like to flip and navigate deep into programs and just want to comb back to the home screen in order to use any other app.

The texting capabilities of this phone matched that of the iPhone and Android handheld device with its on-screen QUERTY keyboard which is quite responsive, messages can be typed vertically or horizontally. The multimedia features are also impressive and the built-in speaker is great for those who don't want to listen to their music or watch videos using headphones. The five megapixel camera produces pictures are well above the average quality of those cameras are found in other handheld devices which by the way don't go as high as five megapixels. All in all, the Acer liquid A1 phone is a great handheld device for those who want more options besides the obvious ones.

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Anyone who searches for a domain registrar wants to get the best service for the best price. Often people think that means that customers must pay premium prices to get good, quality domain registration services. This simply is not true. Many cheap domain registration

companies offer very good service for affordable prices. Besides, the process is going to be the same whether you choose a cheap domain registration company or a more expensive registrar.

It is important to state that while all domains are created equal, all registrars are not. One domain will not be better than another. A customer can purchase mypersonaldomain.com at Network Solutions, Register.com, or CheapDomains.com. No registrar has exclusive access to a domain name that all other registrars do not have. However, registrars differ in the quality of service they offer. This fact will determine whether or not a consumer will choose cheap domain registration or not.

Some registrars offer very basic domain registration services. Others offer bonus features like a domain control panel, starter web page, email forwarding, domain locking, and technical support. It would seem that technical support would be a standard feature of domain registration. However, many companies do not offer technical support. Therefore, customers who are not very knowledgeable about domain registration must beware. Prices increase as customers choose domain registration packages with more and more features.

Cheap domain registration definitely does not suggest an inferior domain. It is important to remember that all domains are the same. The quality of service offered by the registrar is what makes the difference. While customers will find cheap domain registration companies, they may not receive the services offered by more expensive registrars. However, if the person seeking to register a domain does not need as many services, the cheapest route may be the best route.

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When you attempt to register a domain name, you must choose which top-level domain you will be using. The top-level domain (TLD) is actually the extension of the domain name. For example, the .com is the top-level domain or extension in yourdomain.com. Many people think that the extension is included for no specific purpose. This could not be further from the truth. The domain extension or TLD actually indicates what the kind of entity the domain belongs to. For business you always want to buy a domain name that ends in .com. Here is a list of the most common TLDs and what they are used for.

.COM – Anyone with a personal or commercial site may buy a domain name with this extension. However, it is most commonly used by commercial entities. It is, by far, the most popular web domain extension and also the most valuable.

.NET – This is another general TLD, but it is mostly companies involved in internet communications and infrastructure buy a domain name with this extension.

.ORG – Buy a domain name with this extension and you are likely to operate some type of organization. Mostly non-profits register this type of domain.

.BIZ – Since .com has become so crowded with names, many business are registering this domain extension. It still reflects a commercial identity and allows you the opportunity to purchase your company name if it was already used under the more prevalent .com extension. Personal web sites may not use this extension.

.INFO – This top-level domain is steadily rising in popularity. If you have a personal or commercial web site, you can buy this domain name extension.

.PRO – Doctors, lawyers and other professionals buy this domain name extension when they are ready to display web sites with information about themselves and their occupations.

.COOP – This TLD is used by organizations that want to denote their status as cooperatives.

.NAME – Individuals buy this domain name extension to promote their personal web sites It must be comprised of your first and last name.

.AERO – This is a new option for the air-transportation industry.

.MUSEUM – The domain name extension is self-explanatory. In case it’s not obvious, only official museums may use this TLD.

.EDU and .GOV – Both of these domain names are not available for public registration. Only educational institutions and government agencies respectively are allowed to use these domain extensions.

IMPORTANT: For commercial and business use you should concentrate on finding a .com name first. Numerous studies show that surfers will consistently type .com into their browsers before any other extension. If you own MySite.net but your competition owns MySite.com then you will lose hard earned business. This is why .com names are so valuable and why NameSeek deals almost exclusively in the .com TLDs.

Once you own your .com name then you can acquire the .net, .biz, etc. names to keep those names from your competitors. You can point all your names to one web site.

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