Battery

        

   A battery is an electric device which stores chemical energy and converts it to electric energy; it will give voltage which can be used as a source of energy. Batteries consist of two cells inside many voltaic cells. There are two major types of battery used mostly, primary and secondary. The primary battery gives current from the chemical energy inside it but this type can’t be reused and you can’t recharge it too. So it’ll be no use when the power inside is exhausted; it’s for one use only then you have to replace it. The secondary battery (storage) gives current from the chemical energy inside it and this type can be reused and it’s rechargeable too. “Although the term “battery” is properly applied to a group of two or more electrochemical cells connected together electrically, both single-cell and multicell devices are called a battery”.( http://0-www.accessscience.com.library.hct.ac.ae/content.aspx?id=075200 )

       The main usage of a primary battery is that it’s used as a portable device which requires low current voltages and doesn’t support main source power like alarms ,a hand or pocket flashlight or any device which has a battery slot. “Common types of disposable batteries include zinc-carbon batteries and alkaline batteries. Generally, these have higher energy densities than rechargeable batteries, but disposable batteries do not fare well under high-drain application.” ( http://en.wikipedia.org/wiki/Battery_(electricity) ). These type of batteries can’t be recharged because the chemical reaction cannot return to its original form after usage.

     The secondary battery must always be recharged before using it. The secondary battery can be recharged by applying electric current after placing the battery in its special base dock .  “This battery is notable in that it contains a liquid in an unsealed container, requiring that the battery be kept upright and the area be well ventilated to ensure safe dispersal of the hydrogen gas produced by these batteries during overcharging.” ( http://en.wikipedia.org/wiki/Battery_(electricity) ).  


    There're many types of batteries made nowadays. As for primary batteries, there's zinc-carbon which is mainly used in remote controls and flashlights. The main feature is that it's cheap and has low energy density.Lithium-iron sulfide batteries are mainly used in digital cameras and small appliances which are high energy density and expensive. Primary batteries cannot be recharged. As for secondary batteries there's lead-acid which is used mostly for children's electric vehicles and emergency power supply.Lithium-ion battery is used in cellular telephones and portable computers. They have higher energy density and are expensive."The Italian physicist Alessandro Volta is generally credited with having developed the first operable battery." ( http://www.britannica.com/EBchecked/topic/56126/battery)


 The main idea of how the battery works is that it converts the chemical energy to electric energy. Inside the battery there are many voltaic cells; each voltaic cell has two half cells connected in series which contain anions and cations. “One half-cell includes electrolyte and the electrode to which anions (negatively charged ions) migrate, i.e., the anode or negative electrode; the other half-cell includes electrolyte and the electrode to which cations (positively charged ions) migrate, i.e., the cathode or positive electrode” ( http://en.wikipedia.org/wiki/Battery_(electricity) ). The electrodes don’t touch each other but they are connected electrically by the electrolyte. Many cells use two half cells with different electrolytes. Every half-cell is put in a container and a separator that separate it from ions. Each half-cell has an electromotive force that drives electric current from the interior to the exterior cell. The electrical driving force across the terminals of the batteries cell is called the terminal voltage and is measured in volts. The volts develop across the terminal cells depending on the energy given from the chemical reactions of the electrodes and electrolyte. 




Bibliography:


Donald L. Anglin, Donald R. Sadoway, "Battery," in AccessScience, ©McGraw-Hill Companies, 2008, http://www.accessscience.com from http://0-www.accessscience.com.library.hct.ac.ae/content.aspx?searchStr=batteries&id=075200


Alkaline Manganese, Dioxide Handbook and Application Manual,  Energizer, Retrieved 25 August 2008. from http://en.wikipedia.org/wiki/Battery_(electricity)

Encyclopædia Britannica, Brooke Schumm,
http://www.britannica.com/EBchecked/topic/56126/battery


604 words

Japan's History

    

   Japan is known as the Land of the Rising Sun as you can see on its flag. People who live in japan are actually the people who are used to live on the continent of Asia  "Human history didn't begin on the island of Japan"(http://www.japan-101.com) Most likely people arrived in Japan through Korea, Siberia and/or Taiwan/China. During the 5th and 6th centuries, the Chinese writing system and Buddhism were introduced with other Chinese culture by way of the Korean peninsula.


   Traditional Japanese legend said that Japan was founded in the 7th century BC by the ancestral Emperor Jimmu. From the 12th century until the 19th century Shoguns held political control. During the 16th century traders from Portugal, the Netherlands, England and Spain arrived, as did Christian missionaries, During the early 17th century, Japan's Shogunate suspected that they were  a military conquest by European powers and barred all relations with the outside world except for severel contacts with Dutch and Chinese merchants at Nagasaki. "This isolation lasted for 251 years, until commodore Mattew Perry forced the opening of Japan to the West with the convention of Kanagawa in 1854"(http://www.japan-101.com).


   Japan established itself as a regional power through military victories against China (1895) and Russia (1905). Involvement in 'World War I' brought Japan enhanced global influence, and the Treaty of Versailles expanded its land holdings. The postwar years brought prosperity to the rapidly changing nation. It soon began to exercise considerable influence in Asia and and subsequently invaded Manchuria and much of China. On 7 December 1941, Japan launched a successful air attack on U.S naval forces at Pearl Harbor.But in 1943 the tide of the war turned against Japan. The U.S dropped atomic bombs on Hiroshima and Nagasaki in the summer of 1945. Complete collapse of the empire and surrender ensued.They killed approximately 130,000 people instantly ."A divested post-war Japan remained under US occupation until 1952" (http://www.culturegrams.com/). Okinawa remained under US occupation until 1972 to stabilize East Asia, and a major military presence remains there to this day.


Bibliography:
http://0-ic.galegroup.com.library.hct.ac.ae/ic/suic/ReferenceDetailsPage/ReferenceDetailsWindow?displayGroupName=K12-Reference&action=e&windowstate=normal&catId=GALE|00000000ML2O&documentId=GALE|EJ2305100285&mode=view  

http://0-online.culturegrams.com.library.hct.ac.ae/world/world_country_sections.php?contid=3&wmn=Asia&cid=82&cn=Japan&sname=History&snid=2 


 http://www.japan-101.com/history/history_complete_overview.htm

337 words

3D TV

        Over the past 80 years, TVs have evolved from black and white tubes to colorful wall-mounted panel TVs. TVs have always displayed just two dimensions. But, by the end of this year most of the TVs will be in 3D models.


       3D TVs are much more expensive than normal 2D TVs, because of the material needed to get the full set. You'll have to have the glasses, a Blue-Ray player and Blue-Ray disc. Manufacturers are making TVs 40 inches and above. The cheapest TV is about Dhs10,000. The glasses are battery powered and use a liquid-crystal layer on each lens that turns dark when current is applied. Although you'll need the Blue-Ray player, you can buy it in most major shops which should support HDMI 1.4. Finally, you'll need a Blue-Ray movie or game disc that aren't widely available at the moment.


     However, 3D TVs claim to have some disadvantages and these might be solved in time. You can't watch more than two 3D movies after each other otherwise you'll feel dizzy and nauseous which is the effect of the glasses.


Glenn Derene, 3D TV, Popular Mechanics, Sep 2010, 80-83




181 words

My Introduction

    My name is Abdulrahim Ahmed Al Shehhi. I live in Abu Dhabi, but my parents live in RAK. I started living here after I got married 3 years ago. I have one son and his name is Sultan. I work for ADCO more than 6 years ago and I'm sponsored by them in HCT. I didn't finish high school; however I joined ADNOC Technical Institute to finish my studies. I like mostly surfing on the internet and playing video games and watching Anime (Japanese cartoon). I haven't traveled outside the Gulf except for honeymoon when I went to Malaysia. I don't like traveling lot. I want to improve myself to go back to my work and continue my career working for my country.