History of bullets

The history of bullets parallels the history of firearms. Advances in one either resulted from or precipitated advances in the additional. Originally, bullets are round metallic or stone balls placed in front of a volatile charge of gunpowder at the end of a closed tube. As firearms became more scientifically advanced, from 1500 to 1800, bullets changed very little. They remained simple round lead balls, called rounds, conflicting only in their diameter. The growth of the hand culverin and matchlock harquebus brought about the use of cast lead balls as projectiles. "Bullet" is derived from the French word "boulette" which approximately means "little ball". The original musket bullet was a globular lead ball two sizes smaller than the bore, wrapped in a loosely-fitted paper patch which served to hold the bullet in the barrel firmly upon the powder. The loading of muskets was, therefore, easy with the old smooth-bore Brown Bess and similar military muskets.

Description of Quick Ring

The basic Quick Ring system consisted of seven serial links, six of them carrying data, and one a 50 MHz clock signal. Two physical media were specified, sets of twisted-pair copper wiring embedded in a thin plastic strip for use inside a computer, or the same signals using frequency-division multiplexing in a single fiber optic cable for longer links between machines.

The data lines were clocked at seven times the clock signal, so each clock "tick" moved 42 bits of data over the bus for a raw data rate of 2.1 Gbit/s. Ten bits of the 42 were used for signaling and control, leaving the other 32 for data, resulting in a net data transfer rate of 1.6 Gbit/s, or 200 MBytes/s.

Each Quick Ring interface enclosed two of these 200 MB/s links, one for "upstream" and one for "downstream" connections in a point-to-point ring. Since the system was not a bus, machines could talk up and downstream at the same time without interfering with other users. The drawback was that each hop over an intervening point added a latency of up to 1.3 µs.

Since Quick Ring was built in a ring topology there was no need for a dedicated switch, or router, making the system lower cost. It used a circuit switching system, in which the message path is set up before the data is sent, and once set up the connection is very lightweight. This is as opposed to packet switching, in which every message contains all of the data needed to reach the destination, this is more flexible, but adds overhead. Of the 10 bits of control data, four were used to specify a circuit number, allowing for a total of 16 devices per ring.

Protein


Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by a gene and encoded in the genetic code. Although this genetic code specifies 20 "standard" amino acids, the residues in a protein are often chemically altered in post-translational modification: either before the protein can function in the cell, or as part of control mechanisms. Proteins can also work together to achieve a particular function, and they often associate to form stable complexes.

Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of all living organisms and participate in every process within cells. Many proteins are enzymes that catalyze biochemical reactions, and are vital to metabolism. Other proteins have structural or mechanical functions, such as the proteins in the cytoskeleton, which forms a system of scaffolding that maintains cell shape. Proteins are also important in cell signaling, immune responses, cell adhesion, and the cell cycle. Protein is also a necessary component in our diet, since animals cannot synthesise all the amino acids and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that can be used for protein synthesis.

Shoe

A shoe is a thing of footwear worn on the foot or feet of a human, dog, cat, horse, or doll. Shoes may vary from a simple flip-flop to a multifaceted boot. Shoes may have high or low heels, although in western cultures, high heels are considered a woman's style. Shoe materials include leather or image. Athletic shoe soles may be made of rubber.
Dress and casual shoes
Casual shoes, made of leather Dress shoes are categorized by smooth and supple leather uppers, leather soles, and narrow sleek shape. Casual shoes are characterized by sturdy leather uppers, non-leather outsoles, and wide profile. Some designs of dress shoes can be worn by either gender. The majority of dress shoes have an upper covering, commonly made of leather, enclosing most of the lower foot, but not covering the ankles. This upper part of the shoe is often made without apertures or openings, but may also be made with openings or even itself consist of a series of straps, e.g. an open toe featured in women's shoes. Shoes with uppers made high to cover the ankles are also available; a shoe with the upper rising above the ankle is usually considered a boot but certain styles may be referred to as high-topped shoes or high-tops. Usually, a high-topped shoe is secured by laces or zippers; although some styles have elastic inserts to ease slipping the shoe on.