History of Fiber Optics Essay Example

History of Fiber Optics Essay HISTORY OF FIBER OPTICS * In 1840, Daniel Colladon and Jacques Babinet demonstrated the principle of guiding light by refraction. * It was followed by a public demonstration by John Tyndal in 1852. In 1870, Tyndal wrote about the property of total internal reflection in his book about the nature of light. * In 1880, Alexander Graham Bell and Sumner Tainter invented the Photophone, a device capable of transmitting sound waves over beam of light. This is considered as mankind’s first attempt to to use light for carrying information. * In 1930, Clarence Hansel and John Logie Baird demonstrated independently image transmission using fiber. * In 1940’s, Heinrich Lamm successfully transmitted images through a single glass fiber used for internal medical examinations. * In 1951, Harold Hopkins and Narinder Singh Kapany experimented with light transmission through bundles of fiber. Their study led to the development of the flexible fiberscope, which is used in the medical field. It was also Kapany who coined the term fiber optics in 1956. * In 1953, Charles Townes and two of his graduate students developed the MASER (Microwave Amplification by Stimulated Emission of Radiation), and in 1960, Theodore Maiman developed the first LASER ( Light Amplification by Stimulated Emission of Radiation). In 1967, Charles Kao and George Bockham of the Standard Telecommunications Laboratory proposed the cladded fiber cables. * In 1970, Robert Maurer, Donalk Keck and Kapron of Corning Glass developed the first fiber optics with losses less than 2dB/Km. * In 1980’s, losses in fiber optics were reduced to as low as 0. 16 dB/Km. This is due to the development of high-quality light sources and detectors. * In 1990’s, the photonic crystal fiber was developed that can carry high power than the conventional silica based fibers. We will write a custom essay sample on History of Fiber Optics specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on History of Fiber Optics specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on History of Fiber Optics specifically for you FOR ONLY $16.38 $13.9/page Hire Writer

Formal Lab Report Essay Example

Formal Lab Report Essay Example Formal Lab Report Essay Formal Lab Report Essay Once we gathered exactly 12 brine shrimp, we then dumped the contents of the cylinder, including the brine shrimp, into the Petri dish labeled C' for control. We continued to use the pipette to gather 12 brine shrimp and measured the level to 20 ml for each of the other Petri dishes until each Petri sis contained 12 brine shrimp each. Step 4- Before adding any of the concentrations to the Petri dishes, we put the lids on all four of the Petri dishes and set our Stop watch for 5 minutes to observe the brine shrimp in their controlled atmosphere. Once 5 minutes ended, we then counted the number of live brine shrimp and recorded the information on a chart for each individual Petri dish. This was very important because brine shrimp are known for cannibalistic behaviors and losing a brine shrimp to cannibalism would throw off the count of live shrimp after the concentrations have been deed. Step 5- We discussed how affective we thought each concentration would be towards the brine shrimp. Our hypothesis was that ammonia will have the highest LLC-50 (toxicity), bleach will have the intermediate LLC-50 (toxicity) and vinegar will have the lowest LLC-50 (toxicity). : Step 6- Once the hypothesis was made, we gathered our dropper bottles of ammonia, vinegar and bleach. Leaving the C (control) Petri dish aside, we began adding the proper chemicals to the assigned Petri dish using a clean pipette pump assigned to each chemical. Each person was responsible for one Petri dish cause the chemicals had to be added at the same time to get accurate results. The Petri dish labeled V was given 0. 5 ml of vinegar, the Petri dish labeled B was given 0. 5 ml of bleach, the dish labeled A was given 0. Ml of ammonia at the same time and then we gently swirled the liquid in the Petri dishes and quickly replaced the lids and began the stop watch for 5 minutes. Step 7- Once 5 minutes was up We counted the number Of live brine shrimp in each Petri dish and calculated the concentration percent and mortality rate percentage. Using the number of live shrimp, we were able to calculate the umber of dead brine shrimp, which then allowed us to calculate the percent mortality rate at each concentration level. Because the brine shrimp were so small it was optional to use the magnifying glass or hand lens to be able to count the number of live brine shrimp in each dish. Formula for calculating concentration %: Niacin (Mimi) + brine (ml)= ml + amount of chemical added-? Total Volume NEXT (amount of chemical) / (total volume) x Formula for calculating mortality rate 96: (total dead) / (total starting number) x (1 % Step 8- We added another 0. 5 ml of each chemical to their signed Petri dishes a second time and set the stop watch for 5 minutes again. After the five minutes, we counted the number of live brine shrimp and calculated the mortality rate percentage. Step 9- Next began adding 1 ml of each chemical to their assigned Petri dishes, set the stop watch for 5 minutes and when the 5 minutes was over, we recorded the number of live shrimp and calculated the mortality rate percentage. We continued repeating this step, until a total of (five) 1 -ml aliquots had been added and the data was recorded. Step 10- Since the mortality rate for the brine shrimp in the Petri sizes labeled V (vinegar) and A (ammonia) had reached at least 80%, we could then end the test with that particular group of brine shrimp. The remaining Petri dish, B (bleach), had not reached at least 80% mortality rate so we continued to test it. Only this time, we had to begin adding 2 ml of bleach to the Petri dish and set the stop watch for 5 minutes and record data. This Step was done 2 times. Step 11- The addition Of 2 doses Of 2 mils was not changing the mortality rate, so we had to begin adding 5 mils and recording the number of live shrimp after 5 minutes and calculated the retaliatory rate percentage. This was done twice. F-anally on the third dose of 5 mils, we reached a mortality rate of at least 80%. We then recorded our final data. RESULTS: According to the data recorded we came out with different results than our hypothesis.

Spike Lee's Malcolm X Essay Example | Topics and Well Written Essays - 1500 words

Spike Lee's Malcolm X - Essay Example Moreover, his life related events that comprise different aspects from his event filled life was going to get captivated within the framework of the reel life at a magnitude not witnessed by the audiences of Lee ever before. Within the insightful book Spike Lee: Interviews edited by Cynthia Fuchs in an article entitled â€Å"Our Film is Only a Starting Point: An Interview with Spike Lee† by Gary Crowdus and Dan Georgakas, Lee explained his theme behind making a film on the life of Malcolm X, â€Å"Lee explains his primary desire to introduce Malcolm X to young viewers and his awareness that the time limits of even a nearly three and a half hour movie prevented him from producing anything more than a ‘primer’ on one of the America’s most charismatic black leaders † (Fuchs 65). With the level of severe intensity and depth, Lee made a film on the life of a man whose real life events provided the director with enough prudent aspects to frame a complete m otion picture. Thesis Statement The essay intends to depict an introspection based analysis of the film Malcolm X in order to comprehend the inherent themes and the socio-political and religious messages that were meant to be provided by this bio-picture. Malcolm X: Introspection Malcolm X was a movie which included a number of famous personalities such as actors Denzel Washington as Malcolm X and Angela Bassett, Al Freeman, Jr., Albert Hall, and Delroy Lindo. Lee also appears on screen and plays a very small role in supporting as Shorty who is observed to be a real-life associate of Malcolm X. Shorty Jarvis is actually a criminal who has spent time working with Malcolm and is at the same time a jazz trumpeter. It is noteworthy to mention that characters important in the real life of Malcolm X such as Bobby Seale who was the co-establisher of the Black Panther Party, Al Sharpton the Reverent and the future president of South Africa Nelson Mandela, have virtual presence within the pl ot of the film. However, they do not make any cameo appearances. There are vivid hues, sounds and fury which represent the life of the great leader. It was quite hard on the part of the directorial crew to transcript all those events inherent in the real life of Malcolm X to get depicted in the reel phenomena in the course of making the film. The screenplay of Malcolm X, which was a collaborative effort on the part of Spike Lee and Arnold Perl, was drawn mostly from the life events of Malcolm X. These events were mentioned in the book written by Alex Haley and entitled The Autobiography of Malcolm X. The reason behind taking most of the references from this book is that Haley had begun to write this book during 1963. He eventually completed the book following the death of Malcolm X. However, while initiating the project he directly collaborated with Malcolm X himself to write the course of events and facts which constituted the life of the great leader. Furthemore, the book is compr ehensive and very cohesive in nature apart from being one of the most authentic ones because it ponders on the complete course of events which constitute Malcolm X’s life. The film possesses definite contents which are quite significant in terms of both cultural and historical aspects. At the same time, Malcolm X by Spike Lee is not a narrative on reels as it definitely has a strong aesthetic