Software's for Win 7 homebasic and Add-on for chrome

Hi friends this time i would like to share two softwares for windows 7 home basic operating system and a Add-on for Chrome browser.
1.Software-"personalization -setupfile"
Every user of win 7 home basic will not find personalize option in the popup menu,but where as in win 7 professional , ultimate and home premium, users can have it with which one can change the wallpaper of desktop by one click.To get the personalize option for home basic ,download a setupfile "personalization" and get installed in your PC.And now you can see personalization option in popup menu.But we have still left out with "next background option",by which wallpaper changes automatically.
2.Screen Shot Add-on-"CLIPULAR"
    For chrome users,Clipular is one of the best screen shot Add-on.When Clipular is added to chrome,one can take screen shot for the tabs s/he has been working on.Screen shots of full screen or else a part can be taken which will be stored in book(Add-on book),for usage of that image(screen shot) one has to login ,save the file and use it.Since it is add-on for chrome one cannot use it outside chrome.Shortcuts are specified ,which ease its usage.
3. Software-"EPICPEN"
    Those who want to draw on screen, to specify a matter to another user. Epicpen software is useful.By using this,one can able to highlight the matter,that s/he is going to convey.By installing this software one can use a pencil,eraser and color selection.But one cannot draw straight lines or a particular shape,only zigzag lines are allowed.The file can be found at http://sourceforge.net/projects/epicpen/

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DISPLAY DEVICES-EXPLAINED

HI friends in this post we are going to learn about the various types of DISPLAY DEVICES which we had been known.In this the foremost one is 

1.CRT(Cathode ray tube):Experiments to discover more on smallest  particle "atom"(on that time)by J.J thomson, landed him to know about electron.In his experiment he noticed that a ray of particles called electrons(named by G.J stoney) were travelling from cathode to anode,he made this electrons to fall on fluorescent screen when this electrons hit the screen bright spot is produced.On their way from electron gun to screen their is chance of deflection, due to surrounding fields(as electrons are negative),to overcome this he placed horizontal and vertical deflection plates in between the space.So based upon the electrons, which hit the screen display is produced.now a days we can observe CRT's in CRO(cathode ray oscilloscope) .Next to this is 
2.LCD(liquid crystal display):Display by liquid crystals.Normally we know crystals in solid form like rochelle salt,quartz etc unlike here it is liquid crystals,means crystals which are in liquid form or in which the  molecules tend to orientate easily.Actually liquid crystals state is in between solids and liquids.As we know that even on slight increase of temperature will turn this liquid into real liquid so liquid crystal  are effected easily by electric current.Based upon this feature, applied electric current results molecules change their orientation with which display is produced.Next to this
3.LED(light emitting diodes):The diodes which emit light when they are forward biased are LED's.when we look at aluminum-gallium-arsenide(AlGaAs), in this type of semiconductor made diodes the interaction between electrons and holes is interesting , which is responsible to emit light.we knew in previous post "introduction to pn junction diode" about diode condition when no external bias is applied i.e  depletion layer is formed(electrons recombine with holes due to diffusion) on recombination electrons jump from lower orbital to higher orbital and vice versa .Electrons lose(release) energy when they jump from higher to lower orbital and needs(gains) energy to move from lower to higher orbital.The energy released in this process is in form of photons which are basic particles of light,these photons have speed and momentum but have no mass.
you can ask me, why this emission of light doesn't occur in normal Si, Ge diode,the reason is that atoms in normal diode are arranged in a manner that energy drop is relatively short which is invisible to normal eye.By release of photons in led's display is produced.Next to this
4.OLED(organic light emitting diodes):The main differences between led and Oled is the presence of organic layer present between anode and cathode of a diode.The organic layers in Oled are organic layer,conducting layer,emissive layers,the main purpose of this layers are to transport much holes from anode and much electrons from cathode, this will increases the recombination rate which in turn increases the emission of photon which are basic particles of light,this is how display is produced in Oled.

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TRANSMISSION MEDIA

Now a days communication is necessary in every field and to communicate a transmission media is needed. Transmission media is classified into two types.

·         Wire communication (a connection between transmitter and receiver.)

·         Wireless communication (no connection between transmitter and receiver.)

1.                                                          In case of wire line communication, nonelectrical signals are converted into electrical signals                         at the entry and these electrical signals(voltage,current) are transmitted with the help of                                   conductor.The device which transforms it is called the “Transducer”

There are 3 major and well known types of wire communication

·         COAXIAL CABLE:

*It is kind of copper cable mostly used by cable tv companies between communicating antenna and user home tv set and is applied by telephone companies from their offices to poles.

*This cable has three layers enclosed in it, inner layer is conducting copper wire and  two outer layers are used to protect the conducting(cu wire) path from outer damages.

*Major disadvantage regarding this cable is electromagnetic induction

HOW? Here it is said that electrical signals are transmitted by inner cu layer ,it means we have electric field and as these electrons are flowing(current) we have magnetic field around the conductor.so both fields exists. whenever another conductor is brought near to it, we may have collision and there is chance of loss of information.

·         TWISTED PAIR:

*To overcome the loss of information in the coaxial cable Twisted pair cable was introduced as name itself indicates pair of wires are twisted one, to collapse electromagnetic interference.

*It is ordinary wire that connects home and many business computers. To reduce  cross talk and electromagnetic induction between pairs of  wires ,two insulated cu wires are twisted. These are sometime enclosed in single cable this acts as a shield for twisted pair cable.

*For secure information this shield acts as ground and is called as shield twisted pair cable and for home transmit information this shield acts as unshielded and is called unshielded twisted pair cable.

*Major advantage is twisted pair is cheaper than coaxial cable and it overcomes EM induction.

*Disadvantage is slow transfer of information.

·         OPTICAL FIBER:

Up to this security is enough and every one needed the speed and thought of using the light as source to transmit the information as we knew that the speed of light is 3*108m/sec. Based on this technique optical fibre was designed. Similar to coaxial cable it also has 3 layers, outer one is buffer or sheath,middle one is cladding and the inner one where the light is gonna transmit is core. For proper transmission refractive index of core must be slightly greater than cladding. To know how light transmits in the core one should know about the critical angle and total internal reflection.

      *critical angle: When a wave is transmitting from one medium to another medium of different refractive indices and if wave incident angle is greater than 90 degrees this angle is referred as critical angle

      *Total internal reflection: When angle of incident is equal to critical angle then no reflection occurs only refraction into medium.

*By using these light parameters transmission is done in optical fiber. *Major advantages is Optical fiber carries much more information than normal cu wire and is not subjected to EM interference, so most telephone companies long distances lines are made of optical fibers by use of Repeaters at regular distances.
 2.     In case of wireless communication no wired media is present between transmitter and receiver. Here communication is by EM waves HOW? As I said before around a conductor both fields exists and these EM waves are necessary for communication.

The first wireless transmission went on air in early 20^th century using morse code. Later by modulation it made possible for transmitting voices and music via wireless.

Modes:

Wireless communication can be via,

·         Radio communication(Radio frequency)

·         Microwave communication(high frequency)

·         Infrared communication

·         Ultrasonic communication.are made of optical fibers by use of Repeaters at regular distances.

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