Tianamen Square essays

Tianamen Square essays Tiananmen Square is where thousands of Chinese people gathered to try to overthrow the Chinese government. Every writer there witnessed and viewed this event in his or her own way. The writers different versions contradicted so much the audience had every reason to be confused over what really happened. The goal of these writers was to persuade the audience to see this event the way the writer saw it. This event in history can show readers how one event that happened only one way, can be told in many different ways. The Beijing Review interviewed a Chinese Military Official, naturally his story will favor the Chinese government. The leaders of the revolt were referred to as bad people; these bad people were accused of influencing the students and viewers to shamefully overthrow the government. This official also said that their losses were great because of the good mingling with the bad, this caused a mass state of confusion resulting in personal loss. He then made it look like the government assault on the people was necessary, and this showed the integrity of the peoples army. A writer for the New York Times wrote from a neutral perspective. This writer didnt take a side or judge either group. The writer just gave a story from what he or she eye witnessed. This version was descriptive and filled with facts. The writer also explains why the revolt was taking place. The Military Official sided with the government, and the New York Times Writer was neutral. The Official labeled people the Times writer did not. The Official used his opinions in his version. The Times writer used facts to demonstrate his or her eye witnessed account. Both writers wrote about things they saw during the event to prove a point, like when the tank drivers were forced from safety by fire then beaten when they would evacuate. After all the versions were viewed the audience couldn ...

Composites In Boeings 787 Dreamliner

Composites In Boeing's 787 Dreamliner What is the average density of the materials used in a modern airliner? Whatever it is, the reduction in average density has been huge since the Wright Brothers flew the first practical airplane. The drive to reduce weight in airplanes is aggressive and continuous and accelerated by rapidly climbing fuel prices. This drive lowers specific fuel costs, improves the range/payload equation and helps the environment. Composites play a major part in modern airplanes and the Boeing Dreamliner is no exception in maintaining the decreasing weight trend. Composites and Weight Reduction The Douglas DC3 (dating back to 1936) had a take-off weight of about 25,200 pounds with a passenger complement of about 25. With a maximum payload range of 350 miles, thats about 3 pounds per passenger mile. The Boeing Dreamliner has a take-off weight of 550,000 pounds carrying 290 passengers. With a fully loaded range of over 8,000 miles, thats roughly  ¼ pound per passenger mile - 1100% better! Jet engines, better design, weight saving technology such as fly by wire - all have contributed to the quantum leap - but composites have had a huge part to play. They are used in the Dreamliner airframe, the engines, and many other components. Use of Composites in the Dreamliner Airframe The Dreamliner has an airframe comprising nearly 50% carbon fiber reinforced plastic and other composites. This approach offers weight savings on average of 20 per cent compared to more conventional (and outdated) aluminum designs. Composites in the airframe have maintenance advantages too. A typically bonded repair may require 24 or more hours of airplane downtime but Boeing has developed a new line of maintenance repair capability that requires less than an hour to apply. This speedy technique offers the possibility for temporary repairs and a quick turnaround whereas such minor damage might have grounded an aluminum airplane. That is an intriguing perspective. The fuselage is constructed in tubular segments which are then joined together during final assembly. The use of composites is said to save 50,000 rivets per plane. Each rivet site would have required maintenance checking as a potential failure location. And thats just rivets! Composites in the Engines The Dreamliner has GE (GEnx-1B) and Rolls Royce (Trent 1000) engine options, and both use composites extensively. The nacelles (inlet and fan cowls) are an obvious candidate for composites. However, composites are even used in the fan blades of the GE engines. The blade technology has advanced tremendously since the days of the Rolls-Royce RB211. The early technology bankrupted the company in 1971 when its Hyfil carbon fiber fan blades failed in bird strike tests. General Electric has led the way with titanium-tipped composite fan blade technology since 1995. In the Dreamliner power plant, composites are used for the first 5 stages of the 7 stage low-pressure turbine. More About Less Weight What about some numbers? The GE power plants light weight fan containment case reduces aircraft weight by 1200 pounds (more than  ½ ton). The case is reinforced with carbon fiber braid. That is just the fan case weight saving, and it is an important indicator of the strength/weight benefits of composites. This is because a fan case has to contain all debris in case of a fan failure. If it will not contain the debris then the engine cannot be certified for flight. Weight saved in blade turbine blades also saves weight in the required containment case and rotors. This multiplies its saving and improving its power/weight ratio. In total each Dreamliner contains about 70,000 pounds (33 tons) of carbon fiber reinforced plastic - of which about 45,000 (20 tons) pounds is carbon fiber. Conclusion The early design and production problems of using composites in airplanes have now been overcome. The Dreamliner is at the peak of airplane fuel efficiency, minimized environmental impact and safety. With reduced component counts, lower levels of maintenance checking and greater airtime, the support costs are significantly reduced for airline operators. From fan blades to fuselage, wings to washrooms, the Dreamliners efficiency would be impossible without advanced composites.