Fiber Optics Essays - Optical Fiber, Fiber Optics,

Fiber Optics Fiber optics is a branch of optics concerning the transmission of light by means of optical fibers, which are thin strands of glass or other optically transparent materials. Optical fibers can be used to guide light--which is electromagnetic radiation in a certain frequency range--in much the same way that metal wave guides or coaxial cables can be used to guide lower-frequency electromagnetic radiation. Optical Fiber An optical fiber is usually circular in cross section and consists of a core and cladding. An optical fiber for communication applications is typically between about 0.1 and 0.2mm (0.004 and 0.008 in) in diameter. In order that the light waves be guided by the fiber, the core must have a higher index of refraction than the cladding. One such fiber is called a step-index fiber because the index changes abruptly at the interface between the core and the cladding. An important variation of this structure is the graded-index fiber, so called because the index of refraction decreases smoothly outward from the center with no abrupt step. Transmission of Light In the step-index fiber, the light wave is guided by a process called total internal reflection. Only rays that have an angle of incidence at the core-cladding interface greater than the critical angle will be reflected back into the core and thus guided by the fiber. Some rays follow a longer path through the fiber than do others. Thus a pulse of energy entering the fiber undergoes dispersion. This effect limits the bandwidth of the fiber and reduces the amount of information it can transmit. This undesirable feature can be partly overcome by the use of graded-index fibers of proper design. Applications Fiber optics is used in several areas of telecommunications. Advantages of optical fibers include their wide bandwidth, low attenuation, lightness, small cross section, and non-conductivity of electricity. In telephone systems they can provide communication channels to customers and wideband facilities for interconnecting switching offices. Because they are non-conducting, they can be used to provide telecommunications services to locations in electrically hostile environments, such as electric power stations. Because they are completely immune to induced currents from external electromagnetic fields, optical fibers are also useful in environments where electrical noise exists, such as hospitals and factories. Finally, their lightness makes them attractive for use in aircraft and spacecraft as well as in portable communications systems required for tactical military applications. All these properties make them desirable for interconnecting computers and other sophisticated electronic equipment. In communication-system applications, individual fibers usually are used to guide light waves. Other applications employ bundles of fibers. One such application is the transmission of light for illumination. Fibers used for this purpose need not have the cladding or the index gradient of single-fiber light guides because the index step at the glass-air interface serves to guide the light. Another application of fiber bundles is the transmission of images. For this application the fibers must be arranged in the bundle in a coherent fashion. By arranging the locations of the fibers at one end (the output) of the bundle in certain ways with respect to their location at the other end (the input), such functions as magnification, inversion, rotation, distortion, and scrambling of the image can be performed. Bundles of this type can be used for viewing otherwise inaccessible areas, an example being the physician's endoscope. In order to achieve high resolution, fibers with diameters as small as 0.02 mm (0.0008 in) are used in these applications. Fiber bundles are also used in photography, spectroscopy, and image processing.

Washington Views on Factions essays

Washington Views on Factions essays George Washington is the most well-known American in history. The first president of the United States, his portrait has graced the quarter and the one-dollar bill. Our capital city and even a state have borrowed his name. After Washingtons second term as president, he decided not to run for a third term. He wanted to leave the country with some words of wisdom in hopes of guiding the country to longevity without his supervision. One of the most important ideas Washington offered to the country in his Final Address was to stay away from factions. Washington says that although factions are inseperable from our nature, they should be avoided (Farewell Address). Parties form because not only is it human nature to congregate with people of similar interests, but also because a group is more likely to change something in government than a single person is. In Washingtons cabinet, Thomas Jefferson and Alexander Hamilton constantly feuded because of differing views on the economy and the role of government in general. Washington must surely have realized that parties were forming; it prompted him to write about them in his Farewell Address. Washington thought of the divisions in government in different ways; one way was of sectional disunion. Washington urges that the public should indignantly frown upon the first dawning of every attempt to alienate any portion of our Country from the rest, or to enfeeble the sacred ties which now link together the various parts (Farewell Address). He then speaks of the fact that any kind of sectional thoughts could be harmful to every part of the country. Washington says that the North depends on the South for food, while the South depends on the North for ships to transport their goods. In addition to this, Washington says the West needs goods provided by the East, and the East needs wood from the West (Farewell Address). If any of the sections of the ...

Sensory Analysis- Food Properties Assignment Example | Topics and Well Written Essays - 2500 words

Sensory Analysis- Food Properties - Assignment Example This technique is the most appropriate because it can analyze each pixel found on every food surface. It can also quantify the characteristics of the food’s surfaces and the defects that can possibly be on that surface. Different foods have different smells. This due to the different types of perfumes used during the manufacture of the foods. The perfumes used can be either natural or artificial. Natural perfumes can extract from natural sources where they are purified before they are added to the food. On the other hand, artificial sources are produced by mixing different naturally produced aroma together. This will produce different smell from the two natural sources (Gacula 2008). The taste cereals vary from one cereal to another. Tastes can be evaluated from sweet, bitter, sour, and salty. This is each cereal tastes differently from each other. This can be due to the natural sources or the different ways in which they are manufactured. Salty taste can be due to the salts added during processing of the cereal in the factory. Sweet taste is mainly caused by addition of sugary flavors to then cereal during manufacturing. Bitter and sour tastes are caused by addition of acidic flavors to then cereal. This will increase the acidic content of the cereal. Organic or inorganic amino acids are the one used to produce the sour tastes to then cereals (Gacula 2008). Color of every food can add flavor to it. Colors have different effects on cereals. Colors like red, can add sweetness to the cereals as compared to the dark colors. Colors also can be used to as a force of attraction to the customers. People are attracted by colors in different ways. When choosing the color to used in a particular food, people’s interests should be considered to ensure that food is highly marketed. One can be attracted by the way food is colored before they even taste that food (Jelen, 2012). Selection of panels to train as