The Victorian Internet The concept of data communication — transmitting data between two different places through an electromagnetic medium such as radio or an electric wire — pre-dates the introduction of the first computers. Such communication systems were typically limited to point to point communication between two end devices.
Yet they are a remarkable invention with a long and storied history, and an equally exciting future. A battery is essentially a device that stores chemical energy that is converted into electricity. Basically, batteries are small chemical reactors, with the reaction producing energetic electronsready to flow through the external device.
Batteries have been with us for a long time. In the Director of the Baghdad Museum found what is now referred to as the " Baghdad Battery " in the basement of the museum. Analysis dated it at around BC and of Mesopotamian origin.
Controversy surrounds this earliest example of a battery but suggested uses include electroplating, pain relief or a religious tingle. American scientist and inventor Benjamin Franklin first used the term "battery" in when he was doing experiments with electricity using a set of linked capacitors.
The first true battery was invented by the Italian physicist Alessandro Volta in Volta stacked discs of copper Cu and zinc Zn separated by cloth soaked in salty water.
Wires connected to either end of the stack produced a continuous stable current. Each cell a set of a Cu and a Zn disc and the brine produces 0. A multiple of this value is obtained given by the number of cells that are stacked together.
One of the most enduring batteries, the lead-acid battery, was invented in and is still the technology used to start most internal combustion engine cars today. It is the oldest example of rechargeable battery. Today batteries come in a range of sizes from large Megawatt sizes, which store the power from solar farms or substations to guarantee stable supply in entire villages or islands, down to tiny batteries like those used in electronic watches.
Batteries are based on different chemistries, which generate basic cell voltages typically in the 1. The stacking of the cells in series increases the voltage, while their connection in parallel enhances the supply of current.
This principle is used to add up to the required voltages and currents, all the way to the Megawatt sizes. There is now much anticipation that battery technology is about to take another leap with new models being developed with enough capacity to store the power generated with domestic solar or wind systems and then power a home at more convenient generally night time for a few days How do batteries work?
When a battery is discharged the chemical reaction produces some extra electrons as the reaction occurs. An example of a reaction that produces electrons is the oxidation of iron to produce rust.
Iron reacts with oxygen and gives up electrons to the oxygen to produce iron oxide. The standard construction of a battery is to use two metals or compounds with different chemical potentials and separate them with a porous insulator.
The chemical potential is the energy stored in the atoms and bonds of the compounds, which is then imparted to the moving electrons, when these are allowed to move through the connected external device. A conducting fluid such as salt and water is used to transfer soluble ions from one metal to the other during the reaction and is called the electrolyte.
The metal or compound that loses the electrons during discharge is called the anode and the metal or compound that accepts the electrons is called the cathode. This flow of electrons from the anode to the cathode through the external connection is what we use to run our electronic devices.
Primary vs rechargeable batteries A typical car battery. When one of the reactants is consumed the battery is flat.
The most common primary battery is the zinc-carbon battery. It was found that when the electrolyte is an alkali, the batteries lasted much longer.
These are the alkali batteries we buy from the supermarket. The challenge of disposing with such primary batteries was to find a way to reuse them, by recharging the batteries. This becomes more essential as the batteries become larger, and frequently replacing them is not commercially viable.
One of the earliest rechargeable batteries, the nickel-cadmium battery NiCdalso uses an alkali as an electrolyte. In nickel-metal hydrogen batteries NiMH were developed, and had a longer life than NiCd batteries. These types of batteries are very sensitive to overcharging and overheating during charge, therefore the charge rate is controlled below a maximum rate.
Sophisticated controllers can speed up the charge, without taking less than a few hours. In most other simpler chargers, the process typically takes overnight.
Portable applications — such as mobile phones and laptop computers — are constantly looking for maximum, most compact stored energy. While this increases the risk of a violent discharge, it is manageable using current rate limiters in the mobile phone batteries because of the overall small format.Jan 29, · years of international development in under 4 minutes.
History and development of shorthand Through the centuries shorthand has been written in systems based on orthography (normal spelling), on phonetics (the sounds of words), and on arbitrary symbols, such as a small circle within a larger circle to represent the phrase, “around the world.”.
History of the World Wide Web. Written by Ian Peter. In the same year Marc Andreesen founded Netscape Corporation, and the World Wide Web Consortium, which administers development of Word Wide Web standards, was formed by Tim Berners Lee.
Then we really started to see growth. Every year from to , the Internet saw . The World Wide Web History Project Important Events in the History of the World Wide Web "Principal Figures in the Development of the Internet and the World Wide Web".
Facing History and Ourselves is a nonprofit international educational and professional development organization. Our mission is to engage students of diverse backgrounds in an examination of racism, prejudice, and antisemitism in order to promote the development of a more humane and informed citizenry.
The history of the United States is vast and complex, but can be broken down into moments and time periods that divided, unified, and changed the United States into the country it is today: The Library of Congress has compiled a list of historic events for each day of the year, titled "This Day in.