The Adoption Of The Controllable Pitch Propeller By The Outside World

The Adoption Of The Controllable Pitch Propeller By The Outside World Canada is not exactly known for having produced several ground-breaking inventions or discoveries in her time. However, the period of rapid technological advancement that she incurred during the third period of the history of engineering in Canada brought with it several important engineering inventions which had their roots in Canada. The creation of the controllable pitch propeller was one such invention which was perfected in Canada and was so successful that this primarily Canadian development spread throughout the world. Wallace Rupert Turnball lived in Rothesay and it was there that he carried out his experiments in aeronautical theory beginning in 1902. His specialty was that of dihedrals which he studied in a wind-tunnel. He looked at water borne hydroplanes propelled by motor-driven airscrews. An airscrew the Great Britain term for a propeller. A standard propeller consists of anywhere from two to four blades each a section of a helix, the geometric form of a screw thread, hence the term ?airscrew.? The first plane had two air-screws on each side whereas the second one had only one, more highly efficient propeller located at the rear end of craft, near the pilot's seat. However, both had an uneven torque of engine that was in fact destructive to the efforts of the propeller. Turnball experimented with all different types of air-screws; some with a 30? gauge track that were 300' long for truck. With each air-screw he tested, he recorded the propeller thrust, rpm and the forward speed. What determi nes the forward speed is the distance that a propeller will move in the forward direction when the shaft of the propeller is rotated 360o. Assuming that there is no slippage, this distance is termed the geometric pitch. The propellers that Turnball tested had diameters ranging from 1.5' up to 3.5', all different dimensions and shapes. Upon his return to Rothesay in 1918, after the war, he dove into his research and experimentation on a possible controllable pitch propeller, an idea that he had been developing since the autumn of 1916. He ran several tests using rotating electric motor apparatus in order to spin the blades of his propeller. The finished product was a propeller whose pitch can be adjusted by the pilot, at different angles, during flight giving the pilot the ability to command the optimal combination of torque and speed for the situation at any given moment from his aircraft. By means of a small electric motor mounted just in front of the propeller, the pitch of the propeller itself could eventually be adjusted which makes for more efficient take-offs and regular flight than what would be achieved with an everyday ?fixed blade? propeller incapable of any pitch change. Under the supervision of both the Ontario government and the Canadian Air Force, a ground test was run in 1923 on Avro aircraft at Camp Borden, Ontario only to conclude that more research and experimentation was necessary. Four years later, on June 6, 1927, again at Camp Borden on Avro Biplane, Flight Lieutenant G.G. Brookes took Turnball's controllable pitch propeller for it's first air test. Funding was granted immediately to perfect the invention it was such a success. The news of the Canadian invention spread rapidly. Turnball wrote a treatise based on his discoveries and new found technology called ?The Efficiency of Aerial Propellers? which was published in the Scientific American on April 3, 1909. His second and third publications on the subject were entitled ?Laws of Air-Screws? and appeared in The Aeronautical Journal, in the October 1910 and January 1911 issues. For his studies and discoveries, Turnball was awarded the Bronze Medal of Royal Aeronautical Society and was, in addition, elected a ?Fellow.? Come 1914, Turnball had published several scientific articles and found himself one of the world's authorities on the subject. He sold the patents to the controllable pitch propeller in December of 1929. The Curtiss Wright Corporation won the American rights and the Bristol Aeroplane Company, the English rights. In 1935, the Norseman, the most highly successful bush plane in the world at the time, was designed in Canada by Robert Noorduyn, an aviation engineer trained in Holland. The Norseman quickly caught the attention of

Examples and Uses of Metals and Nonmetals

Examples and Uses of Metals and Nonmetals Most elements are metals, but quite a few are nonmetals. Its important to be able to distinguish between the different types of elements. Here is a list of five metals and five nonmetals, an explanation of how you can tell them apart, and some examples of their uses. Five Nonmetals The nonmetals are located on the upper rights include: nitrogenoxygenheliumsulfurchlorine Five Metals Metals usually are hard, dense conductors, often exhibiting a shiny metallic luster. Metallic elements readily lose electrons to form positive ions. Except for mercury, metals are solids at room temperature and pressure. Examples include: ironuraniumsodiumaluminumcalcium How to Tell Nonmetals and Metals Apart The easiest way to identify whether an element is a metal or nonmetal is to find its position on the periodic table. There is a zigzag line that runs down the right side of the table. Elements on this line are metalloids or semimetals, which have properties intermediate between those of metals and nonmetals. Every element located to the right of this line is a nonmetal. All other elements (most elements) are metals. The only exception is hydrogen, which is considered a nonmetal in its gaseous state at room temperature and pressure. The two rows of elements below the body of the periodic table also are metals. Basically, about 75 percent of elements are metals, so if youre given an unknown element and asked to make a guess, go with a metal. Element names can be a clue, too. Many metals have names ending with -ium (examples: beryllium, titanium). Nonmetals may have names ending with -gen, -ine, or -on (examples: hydrogen, oxygen, chlorine, argon). Uses for Metals and Nonmetals Metals uses are directly linked to their qualities. For example: Shiny metals such as copper, silver, and gold are often used for decorative arts, jewelry, and coins.Strong metals such as iron and metal alloys such as stainless steel are used to build structures, ships, and vehicles such as cars, trains, and trucks.Some metals have specific qualities that dictate their use. For example, copper is a good choice for wiring because it is particularly good for conducting electricity. Tungsten is used for the filaments of light bulbs because it glows white hot without melting. Nonmetals are both plentiful and useful. Some of the most commonly used include: Oxygen, a gas, is absolutely essential to human life. Not only do we breathe it and use it for medical purposes, but we also use it as an important element in combustion.Sulphur is valued for its medical properties and is also an important ingredient in many chemical solutions. Sulfuric acid is an important tool for industry: It is used in batteries and in manufacturing.Chlorine, a nonmetal, is a powerful disinfectant. It is used to purify drinking water and swimming pools.

Canada and World War II

This paper studies the causes of WWII and Canadas participation in the war. This paper begins with an exploration of the various causes of WWII, focusing on the rapid increase in the strength and might of fascist leaders and on economic depression. The paper then turns to the participation of Canada in the war. It looks at Canadas motivation to participate, at Prime Minister Kings policies and at specific battles in which Canadians were involved. The paper concludes with evaluations of the consequences of participation in the war for Canada. Second World War was a horrible event, which destroyed an entire generation and robbed millions of their dreams and hopes. This primary cause of this war was the rapid rise in the power and might of fascist regimes in Italy, Russia and Germany. Along with fascist power, it was the economic conditions of various European nations that gave the likes of Hitler a chance to turn their dream of world domination into a reality. This paper studies various causes of the Second World War and shed lights on Canadas participation in this war.

Future Prospects for the Use of Monoclonal Antibodies Research Paper

Future Prospects for the Use of Monoclonal Antibodies - Research Paper Example Later, Behring suggested that active immunity could be produced in humans by a combination of diphtheria toxin and antitoxin serum (Llewelyn, Hawkins, Russell, 1992). However, it was Paul Ehrlich whose work made it possible to produce antiserum to diphtheria toxin on a mass scale. The side chain theory of toxicity was proposed by Ehrlich, according to which, â€Å"toxins mediated their effects on cells through preformed protein side chains and immunity arose because of overproduction of these side chains† (Llewelyn, Hawkins, Russell, 1992.) Cà ©sar Milstein and Georges Kà ¶hler, in 1975, managed to produce in vitro "custom-built" antibodies. They produced a hybridoma by fusing rodent antibody-producing cells with tumor cells from mice bone marrow. A hybridoma, provided with the correct nutrients, can grow indefinitely and divide to produce monoclonal antibodies (antibodies of a single type), on a large scale (Saldanha, 2000.) Five classes of immunoglobulin (Ig) are found in mammals: IgA, IgD, IgE, IgG, and IgM. In some select mammals, IgG and IgA are further subdivided into subclasses (isotypes) due to polymorphisms in the heavy chain (Lipman et al, 2005). The prototype antibody is IgG, which is a glycoprotein having a molecular weight of 150000 Dalton. The molecule has a Y shaped structure, consisting of two identical heavy chain-light chain heterodimers, that is linked together by a disulfide bridge. While the heavy chain comprises three constant immunoglobulins (Ig) domains and one variable (V) domain, the light chains consist of a single constant Ig domain and a single variable domain. The host defense mechanism is initiated by the antigen binding site (Fab) and the Fc region (fragment crystallizable) site (Llewelyn, Hawkins, Russell, 1992.) In order to effectively bind a wide range of antigens, there are numerous mechanisms which come into play.

Product Introduction Examples and Their Categorization Essay

Product Introduction Examples and Their Categorization - Essay Example This product has huge storage capacity and hence can store hundreds of films & music videos inside the device. In the author's view, this product is going to face incompatibility with the recorded movie & music industry given that USB drives are not yet the preferred media of selling recorded films & songs. Hence, this device may end up promoting piracy for end users to use it effectively (media companies do not allow copying). Western Digital will need to work out the details of how media companies will be able to sell their products compatible with this device. Currently, the on-line videos are available only through streaming facilities in sites like Cinema Now. As presented by Bhattacharya & Krishnan et al. (1998. S50-S51) firms may get trapped into incorrect design of new products if the specifications are finalized without considering how the competition and related products would evolve. In an old theory Ansoff (1980. pp139) developed an empirical generalization in which it is presented that new product strategists should consider trends, impact, timing of impact, response time, urgency, threats and opportunities before finalizing the product design and launching in the market. The author feels that this product will currently be successful in regions where video piracy is prevalent thus resulting in an unethical factor to contribute to its success. Sony Potrosacki Proizvodi Bravia TV 200 Hz High Density Television in Croatia Sony has recently launched Potrosacki Proizvodi Bravia TV 200 Hz High Density Television in Croatia [http://www.sony.hr/product/t32-z-series/kdl-40z4500]. This device supports latest technologies like High Density picture (1080 pixels) and smoother motion flow at 200 Hz that is normally displayed at 50 Hz. From the perspective of Croatia, many channels available through wired TV connections do not support HDTV. The satellite connectivity does provide access to HDTV channels but their performance is not good in coastal areas due to heavy rains & thick clouds. Hence, a large part of customer base in Croatia will not be able to differentiate the performance of this model compared to the older TV sets. Overall, it is an excellent addition to the existing product line of Sony but it would take some time for the customers at Croatia to realize the difference. Levinthal & Purohit (1989. pp38-39) presented that when a company launches new products in competition with its older variants in th e same product line, the consumers would compare the performance of the new product with its old variant which needs to be tangibly visible. Sony already has a huge customer base of flat LCD TVs in Croatia. Given that Sony products are very durable, it would be difficult for the organization to tangibly demonstrate the value addition of HDTV systems to the customers to motivate them to purchase them in addition to their existing TV sets. Apple iPhone 3G introduction in Croatia Apple has launched the improved version of iPhone that is compatible with 3G spectrum in Croatia (http://www.apple.com/iphone/countries/hr/). This product again

Early Marriage Essay Example for Free

Early Marriage Essay Marriage is the union of a man and a woman who makes a permanent and exclusive commitment to each other of the type that is naturally fulfilled by bearing and rearing children together. It is essentially a union of hearts and minds, enhanced by whatever forms of sexual intimacy both partners find agreeable but, there are numerous problems a couple can face when marriage happens at an early stage for them. Early marriage is also referred to as child marriage, where emotional and social effects take place, but one of the most common outcomes of early marriage is the withdrawal of girls from formal education. Education is important as it is not all about studying and getting good marks, but it means to discover new things and to gain a vast amount of knowledge. It would be one of the largest losses to a girl if she is married young. As India’s first Prime Minister Jawaharlal Nehru said, â€Å"If u educate a man, you educate an individual; however, if you educate a woman you educate a whole family†. Couples that are married young may also lead to financial problems to occur. As a result, it brings them to poverty, the deprivation of basic human needs. Lack of proper education; do not help the inexperience couples to receive large income for the profession they do. Furthermore, children who grow up in poverty suffer more persistent than children who grow up under better financial circumstances. In addition, children in poverty have a greater risk of displaying behaviour and emotional problems, such as impulsiveness and difficulty getting along with their parents. Although money does not buy happiness, it is true that a financially unstable family can create tensions. Read more: Short Essay on Child Marriage Well, women believe that becoming a parent early means giving your body a better chance to recover from the childbearing demands, which works through preserving your youth. Gynecologists approve of the fact that the early you conceive, the more fit you stay. This could be true but not in all circumstances. It would not be beneficial at all as it increases the risk of dying and a higher chance that the newborn will not survive. According to the studies, mothers in this age group have 20 to 200 percent

Did Israel Cause the Events of September 11? :: Threats to World Peace

I will never forget the strange mix of terror and happiness in my fathers voice the afternoon of September 11, 2001. Knowing his proximity to the World Trade Center(3 blocks), and seeing the terrifying images of the attack on the television screen, I rushed to a phone after class and tried desperately to make contact. The moments that followed seemed like forever. Because of the tie-up in the phone lines, it took about 15 minutes to get through to New York. When I finally did get through, I was relieved to hear his familiar voice. He seemed to feel lucky that he had been fortunate enough to make it out of the terror alive. At the same time, he talked about the difficulty he was already having in getting the horrific events he had witnessed out of his mind. He recounted seeing both Towers fall and the searing images of groups of human beings jumping out of burning buildings hand in hand. Those indelible images will surely stay with him and with us for a lifetime. This story illustrates just how personally the catastrophe has hit home for me. As an American, I believe it has changed the course of our lives, and there are several ways I see America going from here. Many individuals have called for peace, while others for an all out retaliatory strike. I don’t think the question is that simple. It is now up to our leaders to make these difficult choices which may change our way of life as we know it, and we are going to have to make some strong decisions as citizens in order to let them know what we believe needs to get done. I think we have to acknowledge that this event was not an isolated incident. It has made a direct impact on the way each and every American born in this era will live their life. I will never again feel safe while riding in an airplane and that prospect frightens me. If we are no longer safe to do the simple things such as take a trip or go to a ballgame, how can we feel that we are free? In the end, the point of all this seems not only to be an attack on our country, but rather an attack on our freedom.