The United States from the World War II as the Strongest Economy in Research Paper

The United States from the World War II as the Strongest Economy in the World - Research Paper Example Each of the countries which signed their allegiance to the Bretton Woods indicates its recognition of four important factors. This uniformity becomes the cornerstone and the main factor which holds the international economy together. First, all the nations involved recognize and agree that â€Å"the interwar period had conclusively demonstrated the disadvantages of unrestrained flexibility of exchange rates† (Cohen 4). It can be recalled that the Great Depression in the 1930s has become a grim reminder of how floating exchange rates discourages trade and investment while increasing the risk of destabilization and competitive depreciation. On the other hand, architects of the Bretton Woods are also reluctant in adopting a permanently fixed exchange rate like the 19th-century gold standard. Thus, avoiding both maxims, delegates agree on a â€Å"pegged rate† or â€Å"adjustable peg† currency regime or a par value system (Cohen 5). Thus, each country is obligated to choose a par value in their national currency and intervene in order to maintain the exchange rate within 1% above or below the preset rate. Secondly, all nations hold that â€Å"if exchange rates were not to float freely, states would also require assurance of an adequate supply of monetary reserves (Cohen 6).† The financial hegemony held by the United States during the period significantly affected the final decision: â€Å"a system of subscriptions and quotas embedded in the IMF, which itself was to be no more than a fixed pool of national currencies and gold subscribed by each country†.

Nation and Imperialism Essay Example for Free

Nation and Imperialism Essay Imperialism was a very effective form of empowerment over weaker nations for early Britain and other European countries. They dominated and fought over whole continents and countries, arguing over who had conquered more land. There were many reasons why the European’s wanted to imperialize unindustrialized nations such as natural resources. This also made a big impact on said nations, positive and negative. Going on that state of mind, the long term effects of imperialism showed for decades after it really being assumed not an imperialistic state anymore. Some of the reasons the Europeans’ sought out to imperialism is because of social Darwinism, raw materials and natural resources, and prestige. Social Darwinism, the theory of survival of the fittest, was their justification for conquering weaker countries, if the country could fend off invaders then it shall be considered conquered. Raw materials and natural resources were of big importance to the Europeans. Diamonds and other precious assets that could not be found in Europe were found in the countries and could be used for trade, making the economy better. Prestige was also a major influence for imperialistic Europe. If one country had more than another then that country had to conquer more. It was all like a big game to the Europeans, until the natives of the country fought back. Then it was all a strategically thought out counter attack. The impact this made on the conquered was quite noticeable and apparent; both good and bad. A positive effect is the Europeans built them roads, canals, and railways. Showed them the telegraph, newspaper, established schools for them, gave them the blessing of their civilization, and overall made them economized. They were part of modern culture after this occurred. There were new crops; tools and farming methods, which helped increase food production. These changes meant less death to smaller colonies, and overall improve the state of living. A negative effect is the people of the dominated nations were put to work as cheap labor. They had no freedom, had to do what the mother country said since it has so much towering power over them, they were exploited and were taken advantage of. As a result, there were long term effects. The most obvious one would be the formation of nationalism. Imperialism essentially created nationalism. People of different countries under imperialism were  united because of single governmental system, one national language, development of roads, rails, common defense systems, and an unified education system; thus, making people more aware of their identity and rights; eventually leading to independence of their governing countries. The era of imperialism gave birth to new modern world. Aside from their own languages, people of different nations under imperialism also learned the language of the imperialists and started go to diverse places and establishing new links through learning and education of their conquerors. So in conclusion, imperialism had many advantages and disadvantages making it very successful for all involved. The Europeans had reasons and means to imperialize nations, made impacts, and then long term effects which in turn made each country either thrive or perish. The other nations gained economic, social, and political wealth.

Essay on Camus’ The Stranger (The Outsider): The Character of Meursault

The Character of Meursault in Camus' The Stranger (The Outsider)Â   Raymond typifies the beast-character in Camus' The Stranger (The Outsider). He is like Stanley from A Streetcar Named Desire (T. Williams), emotional and manly. Physical solutions come naturally to him, as we see when he mistreats his ex-girlfriend. Ideally, society is exactly the opposite; law and order attempt to solve things fairly and justly. I propose that Meursault is somewhere between these two extremes and that this is the reason why he is a societal outcast. This metaphor explains his major actions in the book: as he struggles to keep his identity, his personality comes in conflict with the norms of society and he is shut down. Just as an animal sticks to instincts, Meursault has a hard time feeling emotions such as remorse or compassion. Even the first page shows us this. Just as an animal leaves its family when it is old enough, never to return, when Meursault hears of his mother's death he is unattached, even uncaring. He had similar feelings when he sent her to live in the old people's home. Meursault has quite a passion for women; he starts dating Marie the very day after he finds out of the death. But like most animals, marriage is basically nonexistent for him; though he acknowledges it, it holds little meaning. When he is isolated in jail, he dreams of women; not Marie, whom he has been seeing for some time, but women in general. Like an animal he feels the urge to mate without any desire for monogamy. An animal has to focus on the present in order to survive, and as far as we know doesn't spend much time cogitating about its past. Meursault always lives in the present, hence his lack of remorse. Th is beast-like quality is one that get... ...s Meursault is not able, because of his very nature, to believe in a hereafter. His human side gives in to his animal side at the end when the chaplain tries forcibly to make Meursault see the light. His animal feels the threat of being tamed, or converted to the ways of human society, and so he explodes to save himself. Only twice in the novel does Meursault experience extreme pressure, once from nature and once from society, and at these points he gives himself over to his beast. This proves devastating from a certain point of view: the first time he compromises his chances of living, and the second time he compromises his chance of an afterlife. This self-preservation instinct is the only thing that keeps him in touch with his bestial side, and in spite of these consequences he triumphs over life in that he remains unique, he does not conform. Â   Â  

Janie in Their Eyes Were Watching God and Holden Caulfield in The Catc

"Dey all useter call me Alphabet 'cause so many people had done named me different names," Janie says (Hurston 9). The nickname "Alphabet" is fitting in Zora Neale Hurston's Their Eyes Were Watching God because Janie is always changing and rearraging, never the same. Janie Crawford was constantly searching for happiness, self-realization, and her own voice. Janie dares not to fit the mold, but rather defy it to get what she wants. On the journey to find her voice, she marries three separate men and each one of these men contribute to Janie’s quest in different ways. In the beginning, the pear tree symbolizes Janie’s yearning to find within herself the sort of harmony and simplicity that nature embodies. However, that idealized view changes when Janie is forced to marry Logan Killicks, a wealthy and well-respected man whom Janie’s Nanny set her up with. Because Janie does not know anything about love, she believes that even if she does not love Logan yet, she will find it when they marry. Upon marrying Logan, she had to learn to love him for what he did, not for that infallible love every woman deserves.  After a year of pampering, Logan becomes demanding and rude, he went as far to try to force Janie to do farm work. It was when this happened that Janie decided to take a stand and run away with Joe. At this time, Janie appears to have found a part of her voice and strong will. In a way, she gains a sense of independence and realizes she has the power to walk away from an unhealthy situation and does not have to be a slave to her own husband. After moving to Eatonville and marrying Joe, Janie discovers that people are not always who they seem to be. While Joe at first seemed to be easy-going and friendly, she wa... ... stay" (Salinger 205). He is repulsed by fake people and wants to be satisfied by something real--something true he can grasp onto. Just as Janie is similar to Holden, Holden is also similar to Janie. Janie is a woman who has overcome the rules and restrictions she was given. Janie was nothing but "a rut in the road. Plenty of life beneath the surface but it was kept beaten down by the wheels" (Hurston 72). Eventually, Janie made it her purpose to rebel against this mold. By the end of the story, Janie has accomplished finding and conquering self-actualization, she has reached her enlightenment through the her marriages to Logan, Jody, and Tea Cake. It is apparant when she tells Pheoby, â€Å"You got tuh go there tuh know  there..Two things everybody's got tuh do fuh theyselves. They got tuh go tuh God, and they got tuh find out about livin' fuh theyselves" (Hurtson 183).

Qualitative Analysis of Anions Essay

The objective of this experiment was to use qualitative analysis to determine the chemical characteristics of four known anions by systemic confirmatory testing. The chemical characteristics observed were to be used to identify an unknown sample. Sulphuric acid was to be added to a carbonate solution and an effervescent reaction would confirm the presence of carbonate anions. Another sample of carbonate solution was to be reacted with hydrochloric acid and the gaseous product was to be reacted with a suspended drop of barium carbonate. The presence of clouding in the droplet would also confirm the presence of carbonate anions. Silver nitrate was to be added to chloride solution and the formation of a white precipitate, silver chloride, would confirm the presence of chloride anions. Ammonium hydroxide would be added to dissolve part of the precipitate. The resultant supernatant solution was to be decanted and re-acidified with nitric acid to reform the precipitate and definitively confirm the presence of the chloride anion. Silver nitrate was to be added to iodide solution and the formation of a yellow precipitate, silver iodide, would confirm the presence of iodide anions. Another sample of iodide solution was to be reacted with drops of acetic acid until sufficiently acidic. Potassium nitrate was to be added to the solution causing a colour change. Methylene chloride was to be added to this sample and shaken to confirm the presence of iodide anions by forming two separate and differently coloured layers. A barium chloride-calcium chloride mixture was to be added to sulphate solution and heated to 90oC. The sample was to stand for a period of time to allow the formation of a  white precipitate, barium sulphate, confirming the presence of the sulphate anion. The addition of hydrochloric acid and subsequent heating were to have no effect on the presence, further confirming the presence of sulphate anions. MATERIALS AND METHODS EQUIPMENT CHEMICALS Test tubes Carbonate Solution, Test tube rack Concentrated Sulphuric acid, H2SO4 Eye dropper 6M Hydrochloric acid, HCL Graduated pipette Barium hydroxide solution Ba(OH)2 Pipette bulb Chloride solution, Cl- Pasteur pipette Iodide solution, I- Beaker 0.1M Silver nitrate, AgNO3 Thermometer Concentrated Ammonium hydroxide, NH4OH 6M Nitric acid, HNO3 6M Acetic acid. HC2H3O ­2 Potassium nitrate, KNO2 Methylene chloride solution, CH2Cl2 Sulphate solution, Barium chloride-Calcium chloride mixture, BaCl2-CaCl2 Unknown Sample 7 SAFETY Carbonate solution is hazardous in case of skin contact (sensitizer, irritant), of eye contact (irritant), inhalation (lung irritant), and ingestion. It should be kept in a cool, well-ventilated area. In case of spill, use appropriate tools to put the spilled solid in a convenient waste disposal container and neutralize the residue with a dilute solution of acetic acid. Hydrochloric acid is very hazardous in case of skin contact (sensitizer, corrosive, irritant, permeator), eye contact (corrosive, irritant), of inhalation (lung sensitizer, respiratory tract irritant), and ingestion (toxic). It should be kept in a dry container, kept away from oxidizing agents, organic materials, metals, alkalis, and moisture. In case of spill, dilute with water and mop with an inert dry material. Residue should be neutralized with dilute sodium carbonate. Chloride solution is hazardous in case of skin contact (irritant, permeator), of eye contact (irritant), ingestion, and inhalation (irritant). In case of spill, dilute with water and mop with an inert dry material and spread water on the contaminated surface. Iodide solution is lightly hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, and inhalation. In case of spill, use appropriate tools to put the spilled solid in a convenient waste disposal container. And spread water on the contaminated surface. Silver nitrate is very hazardous in case of skin contact (corrosive, permeator), of eye contact (irritant), of inhalation, and ingestion.. Silver nitrate kept away from heat, sources of ignition, and combustible material. In case of spill, use appropriate tools to put the spilled solid in a convenient waste disposal container. Ammonium hydroxide is very hazardous in case of skin contact (toxic, corrosive, irritant, permeator), eye contact (irritant), inhalation (toxic to upper respiratory tract), and ingestion (toxic). Water should never be added to ammonium hydroxide and it should be kept a way from incompatibles such as metals, acids. In case of spill, dilute with water and mop with inert dry material. Neutralize residue with dilute acetic acid. Nitric acid is very hazardous in  case of skin contact (corrosive, irritant, permeator), of eye contact (irritant, corrosive), and ingestion. It is slightly hazardous in case of inhalation (lung sensitizer, respiratory tract and mucus membrane irritant). Nitric acid is explosive in the presence of reducing materials, of organic materials, of metals, of alkalis. In case of spill, dilute with water, mop with an inert dry, and neutralize the residue with a dilute solution of sodium carbonate. Acetic acid is very hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation. It is hazardous in case of skin contact (corrosive, permeator), of eye contact (corrosive). It should be kept away from sources of heat, ignition, and oxidizing material. In case of spill, Dilute with water, mop with an inert dry, and neutralize the residue with a dilute solution of sodium carbonate. Potassium nitrite is extremely hazardous in case of skin contact (corrosive, irritant), of eye contact (irritant), of ingestion, and inhalation. In case of spill, use appropriate tools to put the spilled solid in a convenient waste disposal container. Potassium nitrite should be kept dry, away from sources of ignition, heat, and combustible materials. Methylene chloride is very hazardous in case of eye contact (irritant), of ingestion, of inhalation, and skin contact (irritant, permeator). In case of spill dilute with water and mop with an inert dry material. Sulphate solution is hazardous in case of eye contact (irritant), skin contact (irritant), and ingestion. In case of skin contact, wash with soap and water, and cover area with an emollient. In case of spill, Dilute with water, mop with an inert dry material spread water on the contaminated surface. (ScienceLab, 2005) PROCEDURE Please refer to Lab 3: Qualitative Analysis Part 2- Anions chemistry Laboratory Manual 2013-2014, Durham College, pages 11-12 for full list of Materials and Methods. OBSERVATIONS Table 1a: Testing for the presence of Carbonate, CO32- anions 2 drops concentrated H2SO4 added, Test tube shaken Additional Observations Carbonate Solution, 3mL effervescence seen as colourless gas rises from bottom of test tube test tube feels much warmer, upon wafting the gas has a mildly unpleasant, acrid smell The presence of an effervescent reaction indicated that the sample had carbonate anions present. Table 1b: Testing for presence of Carbon Dioxide, CO2 ­ to confirm the presence of CO32- anions 2 drops 6M HCl 1 drop BaOH suspended over test tube Carbonate Solution, 3mL small amount of effervescence noted about 5 seconds after being suspended over test tube, the base of the droplet clouded with white precipitate The addition of HCl to the sample resulted in some rising gas bubbles, indicated that a gas was being formed. The clouding of the barium hydroxide droplet indicated it was reacting with carbon dioxide escaping the tube and thus confirmed the presence of carbonate anions in the sample. Table 2: Testing and confirming for the presence of Chloride, Cl- anions 5 drops 0.1M AgNO3 added NH4OH is added drop-wise Supernatant solution is decanted, 6M HNO3 is added Chloride Solution, 5mL cloudy white precipitate formed precipitate partially dissolved upon addition, distinct clear supernatant formed above remaining precipitate cloudy white precipitate reformed, small white granulations settled at bottom of test tube 6 drops of ammonium hydroxide, NH ­4OH, were added to the sample 6 drops of the nitric, HNO3, were added to acidify the sample The formation of a cloudy white precipitate in the presence of silver nitrate indicated that the sample had chloride anions present. The subsequent addition of ammonium and re-acidification of the sample resulted in the reformation of a cloudy whit precipitate, thus confirming the presence of chloride anions. Table 3a: Testing for the presence of Iodide, I- anions 5 drops 0.1M AgNo3 added Iodide Solution, 5mL cloudy pale yellow precipitate formed The presence of a cloudy yellow precipitate with silver nitrate indicates presence of iodide anion. Table 3b: Testing and confirming the presence of Iodide, I ­- anions Acetic acid is added drop-wise 2 drops KNO2 added 15 drops Methylene chloride added, test tube shaken Iodide Solution, 5mL Blue Litmus Paper confirmed the solution was acidic by turning red solution turned a mustard-brown colour 2 distinct layers formed in the test tube. The bottom layer was reddish magenta, and the top layer was a burnt-orange colour 2 drops of acetic acid, HC2H3O2, were added to acidify sample Upon confirming the sample was indeed acidic, it reacted with the potassium nitrate to change to a mustard-brown colour. The addition of the methylene chloride formed 2 distinctly coloured layers, thus confirming that the solution had iodide anions present. Table 4: Testing and confirming the presence of Sulphate SO42- anions 0.5mL of BaCl2-CaCl2 mixture added Test tube heated, stood for 10 minutes 5 drops 6M HCl, test tube heated Sulphate Solution, 3mL very faint wisps of cloudy white precipitate appeared noticeable cloudy white precipitate distributed throughout solution addition of HCl made test tube feel warm after heating test tube precipitate remained dispersed in solution In each instance of heating, the test tube was placed in a boiling water bath at 90oC The final heating of the test tube was for approximately 5minutes at 90oC The reaction of the sulphate solution with the barium chloride-calcium  chloride solution, when heated, resulted in the appearance of a fine white precipitate, indicating the sample had sulphate anions present. The subsequent addition of HCl and reheating resulting in the solution remaining relatively the same further confirmed that sulphate anions were present. Table 5a: Testing for Unknown Sample 7 for the presence of Carbonate, CO32- anions 2 drops concentrated H2SO4 added, Test tube shaken Additional Observations Unknown Sample 7, 3mL no visible effervescence no noticeable change to test tube’s temperature The lack of effervescence and heat produced by the sample indicated the absence of carbonate anions in the sample. Table 5b: Testing Unknown Sample for presence of Carbon Dioxide, CO2 ­ to confirm the presence of CO32- anions 2 drops 6M HCl 1 drop BaOH suspended over test tube Unknown Sample 7, 3mL no noticeable effervescence suspended droplet remained clear, despite being held over test tube for 15 seconds The sample did not react with the hydrochloric acid to produce a gas that reacted with the barium hydroxide, thus the suspended droplet remained clear. The results further confirmed the absence of carbonate anions. Table 6: Testing and confirming Unknown Sample for the presence of Chloride, Cl- anions 5 drops 0.1M AgNO3 added NH4OH is added drop-wise Supernatant solution is decanted, 6M HNO3 is added Unknown Sample 7, 5mL pale yellow precipitate formed no change to solution no change to solution 6 drops of ammonium hydroxide, NH ­4OH, were added to the sample Nitric acid, HNO3, was unable to be added to the precipitate as no clear supernatant was formed The lack of formation of a cloudy white precipitate in the presence of silver nitrate indicated that the sample did not have chloride anions present. The subsequent addition of ammonium and re-acidification of the sample were rendered purposeless. Table 7a: Testing Unknown Sample for the presence of Iodide, I- anions 5 drops 0.1M AgNo3 added Unknown Sample 7, 5mL cloudy pale yellow precipitate formed The presence of a cloudy yellow precipitate with silver nitrate indicates presence of iodide anion. Table 7b: Testing and confirming Unknown Sample for the presence of Iodide, I ­- anions Acetic acid is added drop-wise 2 drops KNO2 added 15 drops Methylene chloride added, test tube shaken Unknown Sample, 5mL Blue Litmus Paper confirmed the solution was acidic by turning red solution turned a mustard-orange colour  2 distinct layers formed in the test tube. The bottom layer was reddish-purple, and the top layer was an orange-brown 2 drops of acetic acid, HC2H3O2, were added to acidify sample Upon confirming the sample was indeed acidic, it reacted with the potassium nitrate to change to a mustard-orange colour. The addition of the methylene chloride formed 2 distinctly coloured layers, thus confirming that the solution had iodide anions present. Table 8: Testing and confirming Unknown Sample for the presence of Sulphate SO42- anions 0.5mL of BaCl2-CaCl2 mixture added Test tube heated, stood for 10 minutes 5 drops 6M HCl, test tube heated Unknown Sample, 3mL no precipitate formed no noticeable precipitate formed no change to solution In each instance of heating, the test tube was placed in a boiling water bath at 90oC The final heating of the test tube was for approximately 5minutes at 90oC The lack of precipitate formation in the test indicated that the sample was absent of sulphate anions. This result was further confirmed by the subsequent addition of hydrochloric acid and reheating failing to produce a precipitate. DISCUSSION: A strong acid such as H2SO4, sulphuric acid, combined with carbonate produces an effervescent reaction due to the formation of carbon dioxide. The heat felt from the test tube was a result of the exothermic reaction that the carbonate solution underwent in the presence of a strong acid. Sulfuric acid is a strong acid, but only for the first H, so it dissociates into H+ ion and the bisulfate ion, HSO4-. HSO4- is a weak acid and does not dissociate to a great extent, but it also reacts with carbonate (Dartmouth College, 2003). The presence of sulphur may have accounted for the mildly unpleasant scent wafted during the experiment. As indicated by the results of Table 1b, the formation of CO2 acted as a positive indicator for the presence of CO32- in a solution, as expressed by: 2H+(aq) + CO32-(aq) → H2O(l) + CO2(g). The exposure of the produced gas, carbon dioxide, to barium hydroxide resulted in the a cloudy white precipitate due to the formation of barium carbonate as expressed by: H2O (l) + CO2 (aq) + Ba2+ ­Ã‚ ­(aq) → BaCO2 (s) + 2 H+(aq). The addition of 01M AgNO3, silver nitrate, to the chloride solution resulted in the formation of a white precipitate due to the formation of silver chloride as expressed by: AgNO3 (aq) + Cl-(aq) → AgCl(s) + NO3 (g). It is interesting to note that chlorides are generally soluble, with the exception of lead(II) and silver chloride. When concentrated NH4OH was added to the silver chloride precipitate dissolved due to the formation of an ammine complex, [Ag(NH3)2]+. Silver nitrate is generally acidified with dilute nitric acid to prevent the precipitation of other non-halide silver salts (Brown, 2012). Nitric acid acidified the solution due to the addition of H+ ions to the solution, resulting in re-precipitation, thus definitively indicating the presence of chloride anions. This is expressed as AgCl(s) +  2NH3(aq) → Ag(NH3)2+(aq) + Cl-(aq) Ag(NH3)2+(aq) + Cl-(aq) + 2H+(aq) → AgCl(s) + 2NH4+(aq) The addition of 0.1M AgNO3 to the iodide solution resulted in the formation of a cloudy yellow precipitate as expressed by: AgNO3(aq) + I- → AgI(s), which as a precipitate is insoluble in concentrated ammonia. The addition of 6M acetic acid, HC2H3O2, acidified the solution, as confirmed by the litmus test. The newly acidic solution reacted with potassium nitrite, KNO2, reducing the nitrite to nitrogen dioxide as expressed by: I-(aq) + KNO2 → KI(aq) + NO2(g). The liberation of iodine in the reaction resulted in a brownish change in colouration of the solution (SUNY Chemisty, 2005). The failure of the sample to turn a reddish-brown may have been a source of error due to a failure to sufficiently rinse the cleaned test tube with DI water. Methylene chloride, CH2Cl2, which is a non-polar organic compound was added to the solution reacted with the iodide in the solution to form a violet coloured layer of denser solution, which settled at the bottom of the test tube. An alternative means of testing for the presence of iodide anions would have been to use starch, which forma a characteristic blue-black complex. The addition of the barium chloride-calcium chloride mixture, BaCl2-CaCl2, to the sulfate solution resulted in the formation of an insoluble white sulphate, barium sulphate as expressed by: Ba2+(aq) + SO42-(aq) → BaSO4(s). Other insoluble barium salts contain anions of weak acids (CO32-, SO32-and PO43-). Precipitation of these anions is generally prevented by acidifying the solution (Yoder, 2014). The products of the reaction were made more prominent by the catalyzing the reaction with heat, resulting in a more noticeably fine white precipitate distributed throughout the solution. The addition of 6M HCl, hydrochloric acid, served to acidify the solution, further illustrating the insolubility of the barium sulfate precipitate, thereby confirming the presence of sulphate anions. The unknown sample was placed through all confirmatory tests. It failed to react with Sulphuric acid and hydrochloric acid to produce an effervescent reaction, indicating it was carbonate absent. Unknown Sample 7 did not react with the BaCl2-CaCl2 mixture to form a precipitate regardless of heat, indicating the absence of sulphate anions. Unknown Sample 7 formed a pale cloudy yellow precipitate upon the addition of silver nitrate, immediately indicating the presence of iodide anions, disqualifying the need to test  further for chloride. The addition of acetic acid to Unknown Sample 7 provide a sufficient acidic environment for the potassium nitrate to release iodine, thus the solution appeared as a dark mustard orange. The methylene chloride confirmed the presence of iodide anion when a distinct reddish-purple layer settled at the bottom of another distinctly coloured layer of solution. CONCLUSION: Based on the results of the experiment, Unknown Sample 7 demonstrated the formation of a precipitate in the presence silver nitrate, a change in colouration when mixed with potassium nitrate, and the formation of 2 distinctly coloured layers when methylene chloride was added to the solution and shaken. In accordance with the chemical properties exhibited by the 4 known anions during the qualitative testing, it can be concluded the Unknown Sample 4 clearly demonstrated the characteristic chemical responses of a solution with I- ions present. QUESTIONS 1. An ion is an atom that has lost or gained an electron to form a charged particle. 2. An anion is a negatively charged particle due to the atom gaining one or more electrons. A cation is a positively charged particle due to the atom losing one or more electrons. 3. H2SO4(aq) + Na2CO3(aq) → Na2SO4(aq) + H2O(l) + CO2(g) 4a. Aluminum ion: Group IIIA, Al3+ 4b. Sulphur ion: Group VIA, S2- 4c. Iodide ion: Group VIIA, I- 4d. Oxygen ion: Group VIA, O2- 4e. Chloride ion: Group VIIA, Cl- REFERENCES Birk, J. P. (2001, December 4). General Chemistry With Qualitative Analysis. Retrieved from Arizona State University: http://www.public.asu.edu/~jpbirk/qual/qual.html Brown, W. (2012). Chemical Tests. Retrieved from Doc Brown’s Chemistry: http://www.docbrown.info/page13/ChemicalTests/ChemicalTestsa.htm Dartmouth College. (2003, May). ChemLab Chapter 5. Retrieved from Qualitative Analysis of Cations: http://www.dartmouth.edu/~chemlab/chem3-5/qual_an/overview/procedure.html ScienceLab. (2005, October 10). Material Safety Data Sheet (MSDS) List. Retrieved from Science Lab: http://www.sciencelab.com/msdsList.php SUNY Chemisty. (2005, December). Anion Analysis. Retrieved from Chemistry 112: http://employees.oneonta.edu/kotzjc/LAB/Anion.pdf Tro, N. J. (2011). Essential Introductory Chemistry (4th ed.). Toronto: Prentice Hall. White, R. (2013-2014). Qualitative Analysis Part 2- Anions. Chemistry 1 Laboratory Manual, 7-9. Yoder, C. (2014, November). Qualitative Analysis of CAans and Anions. Retrieved from Wired Chemist: http://www.wiredchemist.com/chemistry/instructional/laboratory-tutorials/qualitative-analysis

Plantation and settler colonies

Plantation and settler colonies Introduction Europeans easily defeated all of Africa and managed to separate Africa into minor colonies. A colony is a section of the continent managed by one particular European state. For instance, England managed colonies such as Rhodesia; France controlled nations such as Algeria; Under Imperialism, there were many different types of colonies.Advertising We will write a custom essay sample on Plantation and settler colonies specifically for you for only $16.05 $11/page Learn More This included plantation, settler, occupation and entrepot (Tiffin Ashcroft 2002). This paper will discuss plantation and settler colonies. It will compare and contrast the experience of empires in plantation and settler colonies. In the original imperialism stages, the Europeans aim was to triumph over new lands so as to obtain raw materials which were not accessible in their home country. They also aimed at winning new people to Christianity. Following industrialization, impe rialism of the whites has changed; Imperialists during the post- industrial period looked for raw materials to supply to the factories of the natives while looking for new market places for their already produced goods. This imperialism led to the development of real empires and no empire, however was effectively enough to starve off the penetration of the whites. By the year 1850, the new imperialism established a contest to develop empires overseas (Morgan Hawkins 2006). Discussion Colonialism is the occupation and management of one country by another. The European nations have colonized many world areas for the preceding years. Plantation and settler colonies are two distinct means through which the Europeans developed colonies in the Americans. These were founded on their rationale for colonization. The French established plantation colonies since they were concerned in doing business for furs with the indigenous Americans. Britain was in need of raw materials for its industrie s in the United Kingdom. They, therefore took immense territories of land for cultivation and to use in their industries. They established plantation colonies to satisfy their wants. The British also needed to establish colonies for settlers to arrive and develop new cities that would be governed by the mother nation and pay duties to Britain. These were known as settler colonies (Tiffin Ashcroft 2002). Colonial rule however, differed in distinct ways; the treatment of the indigenous Americans was also different in the varying colonies. The British pressed the resident Americans out of their way to establish the settler and plantation colonies. The French on the other hand, treated their resident Americans well and developed these colonies besides River Mississippi so as to trade moderately (Morgan Hawkins 2006).Advertising Looking for essay on history? Let's see if we can help you! Get your first paper with 15% OFF Learn More Settler colonies were the firs t colonies; in these colonies, many Europeans migrated to Africa and stayed in colonies. It involved the whites and blacks staying and working subsequently. Plantation colony is an early system of colonization; settlers were planted overseas so as to develop a lasting or semi lasting colonial foundation. In this system, colonies were intended to support the growth of western civilization and Christianity among neighboring natives. This is evident in America and especially in the East Coast Plantations (Fredrickson 1988). Plantation colonies were the economical foundation of most of the American colonies. The climax of these plantation colonies was in the 18th century particularly the sugar farms in Caribbean that relied on slave labor and in this case, Britain flourished as the leading slaving state in the Atlantic globe. Slaves were transferred to the Caribbean farms between the year 1690 and 1807. Since the life of slavery on these plantations was ruthless and slaves demised witho ut having children, a steady supply of slaves was necessary; these slaves were obtained from Africa to sustain the plantation economy. There was a decreasing slave population, but in the year 1840, the slaves exceeded the whites. They supplied all the physical labor and this labor led to a spectacular change in the feeding habits of Britons. For instance, the Europeans used four sugar pounds in the year 1700, by the year 1800, this had increased to 16. The bedrock of plantation colonies was agriculture, especially the cultivation of cash crops. Slaves (Tiffin Ashcroft 2002). In settler colonies, the Europeans acquired the fertile African lands and were concerned with making lots of money from these African territories. They however did not want to carry out the hard works associated to it and they therefore made the natives to carry out these tasks on their behalf. In some settler colonies, the whites obliged many Africans to construct railway trails via the country; during this ti me, many Africans died due to starvation and ailments. In plantation colonies, the Europeans forced the Africans to pay profound taxes, this was not done in settler colonies. The Africans had to toil for the Europeans so as to make sufficient money to pay the large levies. Europeans therefore became prosperous while the Africans life worsened (Morgan Hawkins 2006). Settler colonialism involved distant family units shifting into a region and having children in that new country. Land was the foremost resource in settler colonies while natural and human resources such as adaptable souls and labor were the key resources in plantation colonies.Advertising We will write a custom essay sample on Plantation and settler colonies specifically for you for only $16.05 $11/page Learn More Settler colonies were long lasting except in the uncommon circumstances of total evacuation. Settlers went to a country to live; they were initiators of political commands and they ca rried with them a different sovereign capability. Settler colonies usually attempted to make the native residents of a nation fade away, they first utilized their labor before making them vanish. Settler colonies have expansively occurred all through even in the primordial times. The Roman Empire frequently set up settler colonies in recently subjugated regions. The colonists in settler colonies were experts of the Roman military who established farming land; these agricultural societies offered bastions of faithful citizens in unfriendly regions of the Empire. They hastened the Romanization practice amidst the conquered communities who were in proximity to them. An example of a settler colony is the colony near the town of Damascus. The modern settlements of Mezze and Deraya also draw their origin from communities established for settlement by the Romans (Morgan Hawkins 2006). Settler colonies were exclusive in nature. In these colonies, settlers took the place of the indigenous p eople in their native lands and this is different from plantation colonies. In settler colonies, the whites sought an enduring stake in their land while in plantation colonies, the whites sought just to utilize the resources of the natives. Another difference between the two colonies is that, in the plantation colonies, the whites concern was aimed at obtaining cheap labor; this was in the beginning via slavery, but with time, it grew to paid labor while in settler colonies, the main concern lay on exceptional control of the new land. In plantation colonies, the economic interest of the whites relied on labor management rather than land management of the colonized populace. The necessity to protect British rule in settler colonies like Australia weakened with time. Settler domination rose and the termination of slavery during the middle decades undermined governments (Morgan Hawkins 2006). Another principal difference between settler colonies and plantation colonies is that settler s had a tendency of living endearingly in settler colonies. By taking ownership of land and farming on it, there was no much contemplation of the settlers going back to their homes. In settler colonies, the occupying Europeans exterminated, dislocated and marginalized the natives to become a popular non indigenous populace.Advertising Looking for essay on history? Let's see if we can help you! Get your first paper with 15% OFF Learn More In plantation colonies, the settlers comprised of a comparatively small but influential assembly of white planters. These were mainly interested in controlling and administering the utilization of resources as well as conserving the geopolitical concern of the municipal state. These rarely remained on following the termination of their mission. Examples of these colonies include Nigeria and India. Though there were many natives in these countries, they were regulated by a distant power. Colonial rule was majorly set up by the arrival of urban settlers in large numbers. These gained power over the regions by discussions with the former inhabitants. They cultivated unproductive and barely populated areas. With time, these metropolitan settlers became large in numbers. The management of these lands was entirely under the settlers with the original residents being resettled in the rural areas. These original residents were not able to stand for themselves politically. Their sovereignty was confined in the reserves. Expansion developments of the settlers totally served their wants. They did not benefit the natives. They only diminished them to paucity and structural reliance (Fredrickson 1988). Because of the aggressive manner in which the natives were opposed to plantation settlers at first, there was no extensive and organized authority to contradict their settler rules. As time passed by, the settlers gradually stopped to identify with their urban nation. They were able to take their own identity for granted. This was different from the new and the native states which they had left. The resulting colonial fight backs were those amongst the whites. The imperial procedure lingered in the new states. This was to continue defeating the former residents and gain land and riches (Mitchell 2000). In settler colonies, the colonial procedure meant complete take over of the new nation. For instance, Australia and New Zealand saw the diminution of their native populations to small alien inferiors. Their duty on the global scale was acting as ethnographic subjects. A confident degree of ambivalence besieged the survival of the natives. The sagacity of displacement incited the recognition that they belonged nowhere. They, therefore, no longer categorized themselves with the state where they initially came from. They also did not make out effortlessly with the original populace. This was especially tricky in settlements where the native inhabitants formed the greater part of the population. An example of this intricacy experienced by the settlers and the natives is South Rhodesia (Fredrickson 1988). Through an optimistic lens, this ambivalence showed that there is finding of a new custom. This neither belonged to the imperial nation from which they originated nor the native customs that they lived besides. As a custom, it was perceptibly of a cross breed nature, with adoptions from previous societies influencing social and artistic constructs. This incl uded verbal communication, finances and education. Plantation colonies were different from settler colonies especially when it comes to the place of women. European ladies were less appreciated in plantation colonies compared to settler colonies. In plantation colonies, women were taken as companions and instruments of reproducing. In settler colonies, the safety and productiveness of women was crucial to the colonial practice. Settler colonies in association with the ambivalence adjoining the situation of the settlers attested to be a fascinating study field. Reactions to empire in settler communities constituted a site of disputing and contradicting claims. This was a range of recognitions and subjectivities which declined to cohere tidily into oppositional post colonialism (Fredrickson 1988). Settler colonies were quite different from plantation colonies. The Europeans practicing plantation colonies were unable to settle since they were fought away by the Africans. Settler coloni es were better for the life of the natives compared to plantation colonies. Racism was highly manifested in plantation colonies than in settler colonies. Only the blacks were slaves in plantation colonies (Mitchell 2000). A similarity between settler and plantation colonies is in the fact that both the Europeans searched for a technique of getting wealthy at the expense of the Africans. In plantation colonies, the Europeans obliged the Africans to cultivate certain crops. The Whites could then trade these crops in other regions of the globe. The Africans grew crops such as cotton and tobacco. The whites would trade these crops at relatively higher charges and benefit from the earned proceeds. Plantation colonies intricate the Africans. They could not provide for their families since they had to cultivate only cash crops. They did not grow food crops for themselves and their families. As the whites became rich, the Africans became shoddier and were not able to supply or nourish their families. It is clear that in, both plantation and settler colonies, the Europeans grew wealthy at the expense of the blacks (Fredrickson 1988). References Fredrickson, M. (1988) The arrogance of race: historical perspectives on slavery, racism, and social inequality. Middletown: Wesleyan University Press Mitchell, G. (2000) Native vs. settler: ethnic conflict in Israel/Palestine, Northern Ireland, and South Africa. Westport: Greenwood Press. Morgan, D. Hawkins, S. (2006) Black Experience and the Empire. Oxford: Oxford University Press. Tiffin, H., Ashcroft, B. (2002 The empire writes back: theory and practice in post-colonial literatures. Routledge: Routledge Publishers.

Arrhythmia essays

Arrhythmia essays I am doing my report on Arrhythmia. It affects the cardiac muscle, the heart. Arrhythmia causes three types of problems. It causes the heart to pump too slowly (bradycardia), it causes the heart to pump too fast (tachycardis), and it causes the heart to skip beats Bradycardia can be very serious. Some of the symptoms are loss of consciousness, heart failure, or death. Slow heart rates are caused by heart block. The hearts natural pace-maker fails to be conducted to the ventricles, the hearts main pumping chambers. Some treatments can be used. An electronic pace-maker can be inserted and it will send electronic impulse to the heart stimulating it to beat at a normal rhythm. Pace-makers are only inserted when the Tachycardis can also be very serious. It can lead to disabling symptoms and even death. When you have Tachycardis your heart rate is above 100 beats per minute. Tachycardis is caused by heart injuries from past times. Tachycardis usually occurs months or years after a heart attack. A treatment for Tachycardis can be inserting a device called a defibrillator. A defibrillator will detect and treat abnormally fast heart rhythms. The defibrillator monitors the heart and automatically gives electric shocks before Arrhythmia causes permanent damage. If the person does not have a defibrillator a strong electric shock will be given. The cause of Tachycardis is by something not functioning properly in the atria. They are sometimes stimulated by anxiety. Too much caffeine or alcohol and certain drugs can also be the cause. Attacks might last a few minutes or several days. They can be serious and sometimes not serious. Palpitations happen when your heart skips beats. Palpitations have many different symptoms. Some of these symptoms are dizziness, fatigue or fainting as a result of the brain not getting ...

Concentration Definition (Chemistry)

Concentration Definition (Chemistry) In chemistry, the word concentration relates to the components of a mixture or solution. Here is the definition of concentration and a look at different methods used to calculate it. Concentration Definition In chemistry, concentration refers to the amount of a substance per defined space. Another definition is that concentration is the ratio of solute in a solution to either solvent or total solution. Concentration usually is expressed in terms of mass per unit volume. However, the solute concentration may also be expressed in moles or units of volume. Instead of volume, concentration may be per unit mass. While usually applied to chemical solutions, concentration may be calculated for any mixture. Two related terms are concentrated and dilute. Concentrated refers to chemical solutions that have high concentrations of a large amount of solute in the solution. Dilute solutions contains a small amount of solvent compared with the amount of solvent. If a solution is concentrated to the point where no more solute will dissolve in the solvent, it is said to be saturated. Unit Examples of Concentration: g/cm3, kg/l, M, m, N, kg/L How to Calculate Concentration Concentration is determined mathematically by taking the mass, moles, or volume of solute and dividing it by the mass, moles, or volume of the solution (or less commonly, the solvent). Some examples of concentration units and formulas include: Molarity (M) - moles of solute / liters of solution (not solvent!)Mass Concentration (kg/m3 or g/L) - mass of solute / volume of solutionNormality (N) - grams active solute / liters of solutionMolality (m) - moles of solute / mass of solvent (not mass of solution!)Mass Percent (%) - mass solute / mass solution x 100% (mass units are the same unit for both solute and solution)Volume Concentration (no unit) - volume of solute / volume of mixture (same units of volume for each)Number Concentration (1/m3) - number of entities (atoms, molecules, etc.) of a component divided by the total volume of the mixtureVolume Percent (v/v%) - volume solute / volume solution x 100% (solute and solution volumes are in the same units)Mole Fraction (mol/mol) - moles of solute / total moles of species in the mixtureMole Ratio (mol/mol) - moles of solute / total moles of all other species in the mixtureMass Fraction (kg/kg or parts per) - mass of one fraction (could be multiple solutes) / total mass of the mixture Mass Ratio (kg/kg or parts per) - mass of solute / mass of all other constituents in the mixturePPM (parts per million) - a 100 ppm solution is 0.01%. The parts per notation, while still in use, has largely been replaced by mole fraction.PPB (parts per billion) - typically used to express contamination of dilute solutions Some units may be converted from one to another, however, its not always a good idea to convert between units based on the volume of solution to those based on mass of solution (or vice versa) because volume is affected by temperature. Strict Definition of Concentration In the strictest sense, not all means of expressing the composition of a solution or mixture are termed concentration. Some sources only consider mass concentration, molar concentration, number concentration, and volume concentration to be true units of concentration. Concentration Versus Dilution Another common usage of the term concentration refers to how concentrated a solution is. A concentrated solution contains as much solute as it can hold. Chemists often prefer to call such a solution saturated. In contrast, a solution that contains few solute particles is said to be dilute. In order to concentrate a solution, either more solute particles must be added or some solvent must be removed. If the solvent is nonvolatile, a solution may be concentrated by evaporating or boiling off solvent. Dilutions are made by adding solvent to a more concentrated solution. Its common practice to prepare a relatively concentrated solution, called a stock solution, and use it to prepare more dilute solutions. This practice results in better precision than simply mixing up a dilute solution because it can be difficult to obtain an accurate measurement of a tiny amount of solute. Serial dilutions are used to prepare extremely dilute solutions. To prepare a dilution, stock solution is added to a volumetric flask and then diluted with solvent to the mark. Source IUPAC, Compendium of Chemical Terminology, 2nd ed. (the Gold Book) (1997).

Human Resource Management Essay Example | Topics and Well Written Essays - 1250 words - 3

Human Resource Management - Essay Example Boddy (2008) defines Human Resource Management (HRM) as â€Å"the effective use of human resources in order to enhance organizational performance† (p.354). Human resource management is one of the core areas of organizational functions. Even though an organization has many resources such as manpower, materials, machines and money, manpower or human resource seems to the most important one. Context for HRM & key concepts and practices associated with HRM According to Torrington et al. (2011), â€Å"Human resource management (HRM) is the basis of all management activity†( p.4). In fact all the management activities in an organization start from HR. If HR fails to identify and post suitable talents, the organization may not develop properly. The right person at the right place at the right time will always bring benefits to the organization. Since human resource managers are responsible for recruitment, placements, training, development and retention of the employees; the performances of human resource department is vital for the success of an organization. It should be noted that most of the current organizations are operating internationally and diversity in the workforce is not a myth but a fact. Diverse workforce often brings different types of conflicts in the workplace. HR department is responsible for settling such disputes. Strategic HRM is gaining popularity at present because of the globalized nature of organizations a nd the workforce. Paauwe & Boselie (2005) mentioned that â€Å"HRM practices should focus particularly on employee development, the encouragement of learning and knowledge management†. Knowledge management is vital for organizations to stay competitive in the heavily globalized and competitive market. It is necessary to update the knowledge of the employees periodically to make them capable of dealing with the new challenges. Training and development are necessary for the employees to update their skills and knowledge. HR department is responsible for organising training for the employees. As mentioned earlier, majority of the organizations have diverse workforce at present. Diverse workforce often brings a variety of challenges to HRM. Work philosophy, attitudes, skill sets, ethics, values, language, communication means, socioeconomic and cultural backgrounds of diverse workforces are extremely different. For example, many American companies are currently operating in China and these companies have many American employees along with Chinese employees. China and America are entirely different countries in terms of politics and culture. American employees may face lot of problems related to culture and politics while working in China. HR managers are responsible for providing necessary training to such employees before sending them to China. In short, HR management principles are changing as time goes on because of the huge changes happening in the global business world. The success of an organization depends on how well the HR department deals with such changes and makes corrections in its strategies. Along with employee recruitment, training and development, employee retention is another critical area handled by HR department. It should be noted that smart employees always get better opportunities. It is the duty of the HR managers to provide necessary motivation for work to the employees. Better remuneration and incentives alone may not motivate the employees to stick w ith an organization. Along with remuneration, current employees are particular about the work culture, organizational climate and work-life

Comparison of Ground Support Systems Essay Example | Topics and Well Written Essays - 1000 words

Comparison of Ground Support Systems - Essay Example This essay discusses ground support that has been employed in underground mines in order to ascertain the security and protection of the personnel as well as the equipment working there as well as to fulfill the desired engineering purpose of the aperture. The rockmass around an aperture may be considerably fragmented and fractured as a result of the combination of stresses, discontinuities and also, because of the blasting activities for the production or development purposes. Also, pieces of rock, that may range from a few grams to many tones in mass, may fall or slough into the openings of the mine as a result of gravity. Moreover, rock can be violently dumped into the mine openings because of the seismic bursting. The support methods have been developed in order to avoid the falling or ejection of the rock into the mine openings. Screen mesh, resin or mechanical rock bolts, and plain or reinforced shotcrete have been found to be the indispensable features of the production cycle of mining in Canada for year and have improved in the safety of the operator and the equipment along with enhancing the recovery of the minerals. Beginning from the late 1980's, Urylon Plastics Inc. (previously Guelph, Ontario) and in the present times, Mine guard Canada , in association with the Department of Mining Engineering at Queen's University and the MIROC - Mining Industry Research Organization of Canada created an innovative and new rock support system that is known as MIROC MineguardTM. MIROC Mineguard comprises of a thin, durable and highly flexible 2-component polyurethane spray-on liner. The RockguardTM is another polyurethane/polyurea hybrid liner, which has been developed by Futura Coatings Incorporation in Missouri, USA, has become available recently. MineguardTM and Rockguardâ„ ¢ are considered as the best forms of spray-on liners and both of them will referred as polymer liner support in this study. The other spray-on products under testing and development are Master Builder’s epoxy-based product and Fosroc’s latex-based Tekflex product. All systems have been demonstrated not only in the laboratory but also in the underground so that they may work in a various ways. The technical aspects and properties of every support system have been documented well in the literature. Each support system has some technical constraints and benefits, but they will not be included in detail in this study. Although being technically sound with respect to engineering concepts, however, it is also vital to take in to account that whether it is also cost effective or not, and that how each method

Business ethics Essay Example | Topics and Well Written Essays - 750 words - 4

Business ethics - Essay Example that there was a big problem with epidemics of AIDS along with hepatitis B, hepatitis C and some other lethal diseases among American medical workers during the 1990s. The problem concerned the fact that the syringes that hospitals provided their workers with were extremely unsafe, as they were constructed the way that it was easy to get a needlestick injury if used inappropriately. Hence, nurses often got injured in some extreme medical situations that required fast actions; very often they got injuries with the syringes that contained the blood of the patients that had the lethal diseases mentioned above. The cost of such injuries was estimated at $400 million to $1 billion a year. Thus on December 6, 1991, the Occupational Safety and Health Administration (OSHA) brought in safety precautions and obligated hospitals to provide their workers with special trainings concerning prevention of the injuries like that. However the prevention measures caused a lot of discussions, as they were not efficient at all. The point was that considering the difficulty of nurses’ work and their obligation to react immediately most of the time, it appeared to be impossible to teach them how to avoid accidents involving injuries. About 70 percent of all the needles and syringes used by U.S. health care workers were manufactured by Becton Dickinson. Even though the huge harm had been done to medical workers, production of a new design of safer syringes required a lot of funds and resources, as reorganization of manufacturing would cost a lot of money for Becton Dickinson. Therefore the company wanted to shorten their expenses and the only measure they suggested was putting warning labels on their production without any actual engineering changes in the syringes. However, on December 23, 1986, a patent for a syringe with a tube surrounding the body of the syringe that could be pulled down to cover and protect the needle on the syringe was issued to Norma Sampson (a nurse) and

Corporate Financial Information Analysis Essay Example | Topics and Well Written Essays - 4500 words

Corporate Financial Information Analysis - Essay Example In simple words almost all have their own strategies to survive the downturn and afloat their businesses. This report aims to offer an insight into the financial analysis of the two companies in the light of the credit crisis on the financial state of these companies. The past and current financial performances of any company are significant to shape up the future funding strategies of the respective organisation. Shareholders’ wealth creation is significant for any organisation. The impact of credit crisis on the creation of shareholders’ wealth of the two companies is analyzed in this report to make the analysis more judicious. Balfour Beatty and Redrow are two leading players in the housing development and infrastructure industry. Both of these companies are listed in FTSE 250 index. These two are taken up for financial analysis to detect the effect of financial downturn on the market. Balfour Beatty: This UK organisation is a renowned name in road infrastructure, electrical and mechanical engineering, support services and other disciplines (Balfour Beatty, n.d.). In the year 2009, the company ranked 19th among the international leagues table of contractors. Established in the year 1909, it is now one of the largest fixed rail infrastructures contracting company across the globe. The company handles infrastructure building, including civil and rail engineering for a wide range of products. Apart from UK, the organisation also focuses on asset management and capital projects in United States (Hoovers, 2010). In future, its strengths and well-developed strategy will help it to retain the respected position. Redrow is one of the leading property development organisations in UK. Imaginative design and quality customer service have been the key pillars of its operation (Redrow, 2010). At the time of financial downturn, the entire housing market of UK was in a very vulnerable

Irish and Early American differences Essay Example | Topics and Well Written Essays - 1500 words

Irish and Early American differences - Essay Example Ireland again was called Ireland in 1922. English colonization of America started in 1607 and soon these were established throughout the Americas. English American colonies got enmity with Spanish American colonies in the fields of military and economy. Different sorts of colonies were established like charter, proprietary and royal colonies. These colonies were granted independence in 20th century after the American war of independence (Burke 56). Colonization of America was based on certain motives. There were economic, religious and political motives. English colonization of Ireland and then of America were two different experiences in terms of nature and type of people, land and religion. Greater emphasis on these aspects will be laid in following paragraphs. England sent its forces in 684 C.E to carryout raids on Ireland for booty and captives (Kenny 47). English colonization had an aim of supremacy over the complete island. It was very difficult for English rulers to keep contr ol over the entire Ireland. Edward Bruce of Scotland invaded Ireland in 13th century with the help of Gaelic lords against English lords but he could not succeed. This war resulted in devastation of human and animal life on the island. Irish lords regained control over their lost land ultimately (Burke 79). After the war, plague arrived in Ireland in 1348. English people suffered heavily as they were living in the villages and towns of Ireland. Gaelic culture and language again prevailed in the region after the disaster of plague. Therefore, English control got limited up to pale. Adoption of Irish language and customs by Hiberno- Norman lords helped in strengthening Irish hold over the land (Canny 580). After the plague, Norman lords always supported the local Irish people in political, economical and military conflicts with England. English lords faced many difficulties in holding the land and making Irish people captives for slavery. Henry VIII decided to conquer Ireland in 15th century. Kildare was the most famous Irish ruler in 15th century who was open in rebellion activities against the England (Kenny 55). Henry wanted to capture Ireland with a view to minimize the chances of any future rebellion activities and for avoiding any external aggression in future. After the hard and bloody conflicts Henry got control over the Ireland and by the end of 15th century, successfully made it a kingdom. English lords always faced hard time whenever they decided to convert catholic Irish to protestant religion. Brutal and difficult methods were adopted by King Henry but he could not succeed in converting the religion of Irish people. This policy of the king increased hatred in the Irish people against the English rule. Two periods of civil war in Ireland caused huge destruction to Irish catholic land owning class. Catholic followers of Irish land took a major rebel against English rule and killed thousands of Protestants. Crownwell re-conquered Ireland in 1649. This was the bloodiest conflict of Irish history. Land was confiscated from Irish Catholics and was handed over to British settlers. (Kenny 78-79) Irish hatred against English rule increased due to economic situation of the Ireland in 18th century. Agricultural products were being exported and domestic consumption such items were not allowed. Cold and dry spell of 1940 killed about 4 million people due to

Corporate Financial Information Analysis Essay Example | Topics and Well Written Essays - 4500 words

Corporate Financial Information Analysis - Essay Example In simple words almost all have their own strategies to survive the downturn and afloat their businesses. This report aims to offer an insight into the financial analysis of the two companies in the light of the credit crisis on the financial state of these companies. The past and current financial performances of any company are significant to shape up the future funding strategies of the respective organisation. Shareholders’ wealth creation is significant for any organisation. The impact of credit crisis on the creation of shareholders’ wealth of the two companies is analyzed in this report to make the analysis more judicious. Balfour Beatty and Redrow are two leading players in the housing development and infrastructure industry. Both of these companies are listed in FTSE 250 index. These two are taken up for financial analysis to detect the effect of financial downturn on the market. Balfour Beatty: This UK organisation is a renowned name in road infrastructure, electrical and mechanical engineering, support services and other disciplines (Balfour Beatty, n.d.). In the year 2009, the company ranked 19th among the international leagues table of contractors. Established in the year 1909, it is now one of the largest fixed rail infrastructures contracting company across the globe. The company handles infrastructure building, including civil and rail engineering for a wide range of products. Apart from UK, the organisation also focuses on asset management and capital projects in United States (Hoovers, 2010). In future, its strengths and well-developed strategy will help it to retain the respected position. Redrow is one of the leading property development organisations in UK. Imaginative design and quality customer service have been the key pillars of its operation (Redrow, 2010). At the time of financial downturn, the entire housing market of UK was in a very vulnerable

When You Comin Back, Red Ryder Movie Review Example | Topics and Well Written Essays - 500 words

When You Comin Back, Red Ryder - Movie Review Example This play incorporates a set of the 1950s with the costumes and vehicles to match together with characters that play their roles perfectly to depict the tone and reach out to the audience splendidly. The choice of vehicles by the director gives the play a better dimension with each vehicle representing a different class according to its owners. The director of the play uses an old vehicle which needs repair and is pushed by the young couple to depict the class of the couple while the old couple uses a good and well-maintained vehicle which we see Stephen sneaking into and imagining it to be his own. The comment made by Lyle on the play that Stephen can only leave the town once he has bought his mother a vehicle also shows the use of the motor vehicle to show class in the play. The costumes which were used in the play also were well chosen and thought out by the director with every character given a costume matching his/her role in the play. The waitress in the diner is given a uniform which is typical of the waitresses in a diner and also the size and shape depict the 1950s. the old couple is well dressed while the young couple is out of sorts in their dressing and the hairstyles all look well chosen to fit the setting. Stephen and Lyle, on the other hand, have costumes which match their status with Stephen being dressed in a pair of jeans and a shirt while Lyle is dressed in old canvas trousers and a cowboy hat. According to Hoffman (Hoffman, 18) asserts that a character should be serious as he does not know its funny (unless joking). This is well depicted in the play especially the waitress Angel who is acting mousy and her behavior throughout the play in her behavior and lack of understanding any sarcasm by the other actors in the play. The attitude by Stephen towards the clients coming into the diner is also of note as he does not approve of any client and treats them with a bad attitude. Â  

David Humes Thoughts On Empiricism Essay Example for Free

David Humes Thoughts On Empiricism Essay One of the most notable figures in the history of western philosophy was Scottish philosopher David Hume. Hume was widely known for his views on Empiricism. Empiricism has been pondered since the beginnings of philosophy by many famous figures, from Aristotle to John Locke. (Wikipedia) Empiricism claims that human knowledge is founded on observation and use of the five senses. Hume published a literary work titled Enquiry concerning Human Understanding. This had a profound impact on empiricist philosophy. (Heter) In section 2 of the Enquiry concerning Human Understanding, titled Of the Origin of Ideas, Hume makes distinctions about impressions and ideas. Simply stating how a memory obtained from the central nervous system can never reach the level of raw, vividness that the original impression had made. An example of this concept can be something along the lines of experiencing free fall. We have all experienced free fall at some point in our lives. Simply recalling that moment can never fully allow us to grasp the gut wrenching excitement of pure gravity. An interesting thought brought forward in section 2 is The Copy Principle. Hume states But though our thought seems to possess this unbounded liberty, we shall find, upon a nearer examination, that it is really confined within very narrow limits, and that all this creative power of the mind amounts to no more than the faculty of compounding, transposing, augmenting, or diminishing the materials afforded us by the senses and real life experience†¦(Enquiry, Section II) In laymans terms, imagination of the human mind might be perceived as limitless. However, in  reality, it is really a combination of sensory information and real life experiences. To this end, Hume believes that there are no truly original ideas. Everything we can conceive is a copy or modification of material afforded to us by our surroundings. Examples of this can be found all around us. Such as the design of a plane matching the shape of a bird or Velcro behaving as burdock burrs. (Bloomberg) An interesting point Hume brings to our attention is the Blind Man Argument. Hume claims that a person born blind has no notions of what color is. If you grant that individual the ability to see, you present him with a new channel for ideas. Without this inlet, he would have no idea what color is. Therefore, color must come from the senses. (Enquiry, Section II) One might object to Humes copy principle by stating that original ideas are created quite frequently. A perfect example of this is the telephone. There was no object in the known universe that was able to transmit encoded sound waves through electrical wire over vast distances to a receiver before the telephone. This invention came into existence through pure innovation. The blind man argument presents an error. Just because a blind man cannot make an association between the word red and the color red doesnt mean that they have never seen it before. Perhaps the man has seen the color red countless times in his dreams. However, without having another individual identify the same color and help him form the association between the word and the color, the blind man will never know what red means. Countering my objection to The Copy Principle, all the natural resources we are afforded on earth  can be combined, transformed or restructured to create something else. Basically, everything we have created can be broken down to the raw materials found within our environment. This makes it impossible to create something truly new. The telephone is simply a combination of oil, copper, aluminum, silicone, ect. In defense of The Blind Man Argument, people born without the ability to see, claim they see nothing. They might understand how the color spectrum works but they will never be able to sense what the actual color looks like. For one to know the answer to this debate, he or she have the ability to see and be blind at the same time. Hume certainly brings up some interesting concepts. For this reason, scholars have been studying his ideas for centuries. Empiricism and rationalism are in constant disagreement. Both philosophical notions are extremely hard to disprove. Works Cited Hennighausen, Amelia, and Eric Roston. 14 Smart Inventions Inspired by Nature: Biomimicry: Nature as RD Lab. Bloomberg. com. Bloomberg, 19 Aug. 2013. Web. 20 Sept. 2013. Heter, T. Storm. Empiricism. First Philosophy: A Handbook for Beginning Philosophers. N. p. : n. p. , n. d. 15-21. Print. Hume, David. Section II: Of the Origin of Ideas. An Enquiry concerning Human Understanding. N. p. : n. p. , 1784. N. pag. Print. Wikipedia contributors. David Hume. Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 30 Aug. 2013. Web. 21 Sep. 2013. Wikipedia contributors. Empiricism. Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 15 Sep. 2013. Web. 21 Sep. 2013.

The real-time transport protocol

The real-time transport protocol Abstract This paper describes the Real-time Transport Protocol (RTP) with the emphasis on the securities, confidentiality and authenticity. This system takes a media file as input, encrypt it and create a message digest on the encrypted data then transmit it to the user. On the other side the receiver again calculate digest and compare it with the received one, if match occurs then decrypt and play it in the real time player. In current specification of RFC1889, only the confidentiality is described and authenticity is left for lower layer protocols. This work made experiment both on authenticity and confidentiality. For authenticity MD5, SHA-1 and SHA-2 hash algorithms can be used and for confidentiality AES-128 and Triple DES cryptographic algorithms can be used. In fact, SHA-2 is better than other hash algorithms in terms of security but SHA-1 is better than SHA-2 in terms of time efficiency. On the other hand, AES-128 is better than Triple DES in terms of time efficiency and security. So SHA-1and AES-128 is chosen for authenticity and confidentiality respectively for the security of RTP. The experiment is performed on J2SDK1.5. Keywords: Real-time transport protocol; Transport control protocol; Cryptographic algorithm; Hash algorithm. 1. Introduction: In recent days Computer and Internet has become essential part of human life and people demanding more and more access and use data over the Internet in Real-time with efficient secure manner. A new protocol Real-time Transport Protocol (RTP) and its associated Protocols helping people to use data over the Internet in their real-time applications. In this paper, the analyses of the securities of RTP, an approach to modify RTP for authenticity are presented. Also the position of RTP in Computer Network Layers, its usage scenario and the importance of time consideration to transmit streams using RTP are discussed and shown their analytical results. RTP is intended to be malleable to provide the information required by a particular application and will often be integrated into the application processing rather than being implemented as a separate layer. RTP is a modular protocol. The usage of RTP for a specific purpose requires an application area specific RTP profile. RTP profiles are used for refining the basic RTP protocol to suit for a particular application area. RTP profiles define how and by which formats data is encapsulated to RTP packets. RFC 1889 defines basic fields for the transportation of real time data. It also defines Real-time Transport Control Protocol (RTCP), whose purpose is to provide feedback on transmission quality, information about pa rticipants of RTP session, and enable minimal session control services. RTP is an application level protocol that is intended for delivery of delay sensitive content, such as audio and video, through different networks. The purpose of RTP is to facilitate delivery, monitoring, reconstruction, mixing and synchronization of data streams. RTP provides end-to-end network transport functions suitable for applications transmitting real-time data. RTP is a protocol framework that is deliberately not complete. RTP dose not provide quality of service means that it has no flow control, no error control, no acknowledgement and no mechanism to request retransmission. It does not do so because if a missing packet is retransmitted then it might happen that the retransmitted packet reach to the user too late to use which may hamper real-time use of streams. If some packets are lost during transmission (it is very common for Real-time protocols) then the lost packets are generated by interpolation rather than retransmission. However to improve performance of RTP another protocol; Real-time Transport Control Protocol is used with RTP. It handles feedback on delay, jitter, bandwidth, congestion, and other network properties. RTCP also handles inter stream synchronization. The problem is that different streams may use different clocks, with different granularities and different drift rates. RTCP can be used to keep them in synchronization. RTCP is also supports the use of RTP level translators and mixers. The paper is organized as follows. In section 2, RTP use scenarios are discussed. In section 3, position of RTP in computer network is discussed. In section 4, time consideration in RTP is discussed. In section 5, RTP packet format, its data transfer protocol and Real-time Transport control Protocol (RTCP) is discussed. Section 6 details the hash and cryptographic algorithms for RTP security while section 7 shows the result and performance analysis. Lastly, section 8 points out the conclusion inferred from the work. 2. RTP use scenarios: The following sections describe some aspects of the use of RTP. The examples are chosen to illustrate the basic operation of applications using RTP. In these examples, RTP is carried on top of IP and UDP and follows the conventions established by the profile for audio and video specified in the companion Internet-Draft draft-ietf-avt-profile. 2.1 Simple multicast audio conference: A working group of the IETF meets to discuss the latest protocol draft, using the IP multicast services of the Internet for voice communications. Through some allocation mechanism the working group chair obtains a multicast group address and pair of ports. One port is used for audio data, and the other is used for control (RTCP) packets. This address and port information is distributed to the intended participants. If privacy is desired, the data and control packets may be encrypted, in which case an encryption key must also be generated and distributed. The exact details of these allocation and distribution mechanisms are beyond the scope of RTP. The audio conferencing application used by each conference participant sends audio data in small chunks of, say, 20 ms duration. Each chunk of audio data is preceded by an RTP header; RTP header and data jointly form a UDP packet. The RTP header indicates what type of audio encoding (such as PCM, ADPCM or LPC) is contained in each packet so that senders can change the encoding during a conference, for example, to accommodate a new participant that is connected through a low-bandwidth link or react to indications of network congestion. The Internet, like other packet networks, occasionally loses and reorders packets and delays them by variable amounts of time. To cope with these impairments, the RTP header contains timing information and a sequence number that allow the receivers to reconstruct the timing produced by the source, so that in this example, chunks of audio are contiguously played out the speaker every 20 ms. This timing reconstruction is performed separately for each source of RTP packets in the conference. The sequence number can also be used by the receiver to estimate how many packets are being lost. Since members of the working group join and leave during the conference, it is useful to know who is participating at any moment and how well they are receiving the audio data. For that purpose, each instan ces of the audio application in the conference periodically multicasts a reception report plus the name of its user on the RTCP (control) port. The reception report indicates how well the current speaker is being received and may be used to control adaptive encoding. In addition to the user name, other identifying information may also be included subject to control bandwidth limits. A site sends the RTCP BYE packet when it leaves the conference. 2.2 Audio and Video Conference: If both audio and video media are used in a conference, they are transmitted as separate RTP sessions RTCP packets are transmitted for each medium using two different UDP port pairs and/or multicast addresses. There is no direct coupling at the RTP level between the audio and video sessions, except that a user participating in both sessions should use the same distinguished (canonical) name in the RTCP packets for both so that the sessions can be associated. One motivation for this separation is to allow some participants in the conference to receive only one medium if they choose. Despite the separation, synchronized playback of a sources audio and video can be achieved using timing information carried in RTCP packets for both sessions 2.3 Mixers and translators: So far, it is assumed that all sites want to receive media data in the same format. However, this may not always be appropriate. Consider the case where participants in one area are connected through a low-speed link to the majority of the conference participants who enjoy high-speed network access. Instead of forcing everyone to use a lower-bandwidth, reduced-quality audio encoding, an RTP-level relay called a mixer may be placed near the low-bandwidth area. This mixer resynchronizes incoming audio packets to reconstruct the constant 20 ms spacing generated by the sender, mixes these reconstructed audio streams into a single stream, translates the audio encoding to a lower-bandwidth one and forwards the lower-bandwidth packet stream across the low-speed link. These packets might be unicast to a single recipient or multicast on a different address to multiple recipients. The RTP header includes a means for mixers to identify the sources that contributed to a mixed packet so that corr ect talker indication can be provided at the receivers. Some of the intended participants in the audio conference may be connected with high bandwidth links but might not be directly reachable via IP multicast. For example, they might be behind an application-level firewall that will not let any IP packets pass. For these sites, mixing may not be necessary; in which case another type of RTP-level relay called a translator may be used. Two translators are installed, one on either side of the firewall, with the outside one funneling all multicast packets received through a secure connection to the translator inside the firewall. The translator inside the firewall sends them again as multicast packets to a multicast group restricted to the sites internal network. Mixers and translators may be designed for a variety of purposes. An example is a video mixer that scales the images of individual people in separate video streams and composites them into one video stream to simulate a group scene. Other examples of translation include the connection of a group of hosts speaking only IP/UDP to a group of hosts that understand only ST-II, or the packet-by-packet encoding translation of video streams from individual sources without resynchronization or mixing. 3. Position of RTP in computer network: As a consequence it is decided to put RTP in user space but should run over User Datagram Protocol (UDP, it is connectionless transport protocol). RTP operates as follows. The multimedia (streams) application consists of multiple audio, video, text and possibly other streams. These are fed into the RTP library, which is in user space along with the application. This library then multiplexes the streams and encodes those RTP packers, which it then stuffs into a socket. At the other end of socket (in the operating system kernel), UDP packets are generated and embedded in IP packets. If computer is on an Ethernet, the IP packets are then put in Ethernet frames for transmission. The protocol stack for this situation is shown in Figure 1. Since RTP runs in user space not in OS kernel and in the Ethernet it packed by UDP, then IP and then Ethernet, so it is difficult which layer RTP is in. But it is linked to application program and it is generic, application independent protocol that just provides transport facilities, so it is a transport protocol that is implemented in the application layer. The packet nesting is shown in Figure 2. The main goal of RTP is to make the transmitting streams real-time applicable. On the other hand if security is provided to the transmitting streams, then some extra time is needed to encrypt the streams or to make signature such as making digest from entire movie or audio files. So in concern of time, security is added with some overheads to the RTP. The goal of this paper is to choose algorithms and procedures that make RTP reliable in term of time and security. 4. Time consideration in RTP: Let a video or audio file over the Internet in real-time is intended to access, then here the most important parameter is bandwidth of the Network. And the next important parameters are minimum clip size and its duration as well as processors speed of both server and client. At first let it be assumed that files are accessing without security consideration. Then let review the following mathematical calculations for audio or video clip to access in real-time. One second file clip size = oneSecFileSize bits, Time duration of each clip = cSec seconds, Upload Transmission rate = uRate bits per second, Download Transmission rate = dRate bits per second, Time to upload, tUpload = oneSecFileSize *cSec/uRate, Time to download, tDownload = oneSecFileSize If the time to upload or download a clip is more than the time to play a clip, the player will wait and the receiver will see a break, i.e. max (tUpload, tDownload) >cSec. For the continuous playing of clips, the following condition must be true: Max (1/uRate, 1/dRate) > 1/ oneSecFileSize Min (uRate, dRate) > oneSecFileSize According to the equation, the waiting time between clips at the receiver does not depend on clip size. The only variable that matters for a continuous playback is the size of a one-second file and that the provided upload and download rates meet the above condition. Lag time between playing and capturing is: cSec + tupload + tdownload From the above equation, the maximum lag with no break in the feed is 3*cSec and the minimum lag is cSec. To get the clip as close to real time as possible, cSec should be reduced. Next, apply the above analysis to the following cases: 4.1 Both sender and receiver have a low bandwidth modem connection: Lets assume the uRate = dRate = 20K bits/sec. In this case, the one-second file size should be less than 20Kbits. If the clip size is 10 seconds, the maximum playback lag will be 30 seconds. It is observed that the minimum file size for transmitting a one-second video (with no audio) is 8Kbits using H263 encoding and 12896 pixels video size. It is also observed a minimum file size with the video and an 8-bit mono audio with an 8000Hz-sampling rate to be 80Kbits. 4.2 Either the sender or the receiver has a low bandwidth connection: Lets assume that the lower rate is 20Kbits/sec and the other rate is much higher. In this case the one-second file size should be less than 20Kbits, but the maximum playback lag is about 20 seconds if the clip size is 10 seconds. 4.3 Both sender and receiver have high bandwidth: It is noted here that the one-second-clip size may vary from the format to format of the file, that is, how the file is encoded. For example the one-second-clip size of MP3 is less than in WAV file. But the important point here is that when cryptographic algorithms are applied in the clip then an extra time is added to the processing of clip with each side. So if applied strong encryption algorithms to the clip then extra more time is needed to both sides and upload or download time will be affected and time lag between them will also be changed. So real time access of data is also affected. Therefore, providing security in RTP the considered parameters are bandwidth of the network, file format of clips, upload and download of the clip, processor and memory speed and applying cryptographic and hash algorithms. 5. RTP packet format and data transfer protocol: RTP packet formats and its Data Transfer Protocol is as follows: 5.1 RTP fixed header files: Whenever data are transferred with RTP, it always add a fixed header with the payload. The RTP header has the following format shown in figure 4: The first twelve octets are present in every RTP packet, while the list of CSRC identifiers is present only when inserted by a mixer. Version (V) is 2 bits wide. This field identifies the version of RTP. The version defined by this specification is two (2). Padding (P) is 1 bit wide. If the padding bit is set, the packet contains one or more additional padding octets at the end which are not part of the payload. The last octet of the padding contains a count of how many padding octets should be ignored. Padding may be needed by some encryption algorithms with fixed block sizes or for carrying several RTP packets in a lower-layer protocol data unit. Extension (X) is 1 bit wide. If the extension bit is set, the fixed header is followed by exactly one header extension. CSRC Count (CC) is 4 bits wide. The CSRC count contains the number of CSRC identifiers that follow the fixed header. Marker (M) is 1 bit wide. The interpretation of the marker is defined by a profile. It is intended to al low significant events such as frame boundaries to be marked in the packet stream. A profile may define additional marker bits or specify that there is no marker bit by changing the number of bits in the payload type field. Payload type (PT) is 7 bits wide. This field identifies the format of the RTP payload and determines its interpretation by the application. A profile specifies a default static mapping of payload type codes to payload formats. Additional payload type codes may be defined dynamically through non-RTP means. An initial set of default mappings for audio and video is specified in the companion profile Internet-Draft draft-ietf-avt-profile, and may be extended in future editions of the Assigned Numbers RFC [9]. An RTP sender emits a single RTP payload type at any given time; this field is not intended for multiplexing separate media streams. Sequence number is 16 bits wide. The sequence number increments by one for each RTP data packet sent, and may be used by the rece iver to detect packet loss and to restore packet sequence. The initial value of the sequence number is random (unpredictable) to make known-plaintext attacks on encryption more difficult, even if the source itself does not encrypt, because the packets may flow through a translator that does. Time stamp is 32 bits wide. The timestamp reflects the sampling instant of the first octet in the RTP data packet. The sampling instant must be derived from a clock that increments monotonically and linearly in time to allow synchronization and jitter calculations. The resolution of the clock must be sufficient for the desired synchronization accuracy and for measuring packet arrival jitter (one tick per video frame is typically not sufficient). The clock frequency is dependent on the format of data carried as payload and is specified statically in the profile or payload format specification that defines the format, or may be specified dynamically for payload formats defined through non-RTP mean s. If RTP packets are generated periodically, the nominal sampling instant as determined from the sampling clock is to be used, not a reading of the system clock. As an example, for fixed-rate audio the timestamp clock would likely increment by one for each sampling period. If an audio application reads the blocks covering 160 sampling periods from the input device, the timestamp would be increased by 160 for each such block, regardless of whether the block is transmitted in a packet or dropped as silent. The initial value of the timestamp is random, as for the sequence number. Several consecutive RTP packets may have equal timestamps if they are (logically) generated at once, e.g., belong to the same video frame. Consecutive RTP packets may contain timestamps that are not monotonic if the data is not transmitted in the order it was sampled, as in the case of MPEG interpolated video frames. SSRC is 32 bits wide. The SSRC field identifies the synchronization source. This identifier i s chosen randomly, with the intent that no two synchronization sources within the same RTP session will have the same SSRC identifier although the probability of multiple sources choosing the same identifier is low, all RTP implementations must be prepared to detect and resolve collisions. If a source changes its source transport address, it must also choose a new SSRC identifier to avoid being interpreted as a looped source. The CSRC list contains 0 to15 items, 32 bits each. The CSRC list identifies the contributing sources for the payload contained in this packet. The number of identifiers is given by the CC field. If there are more than 15 contributing sources, only 15 may be identified. CSRC identifiers are inserted by mixers, using the SSRC identifiers of contributing sources. For example, for audio packets the SSRC identifiers of all sources that were mixed together to create a packet is listed, allowing correct talker indication at the receiver. 5.2 Multiplexing RTP sessions: For efficient protocol processing, the number of multiplexing points should be minimized. In RTP, multiplexing is provided by the destination transport address (network address and port number), which defines an RTP session. For example, in a teleconference composed of audio and video media encoded separately, each medium should be carried in a separate RTP session with its own destination transport address. It is not intended that the audio and video be carried in a single RTP session and demultiplexed based on the payload type or SSRC fields. Interleaving packets with different payload types but using the same SSRC would introduce several problems: If one payload type were switched during a session, there would be no general means to identify which of the old values the new one replaced. An SSRC is defined to identify a single timing and sequence number space. Interleaving multiple payload types would require different timing spaces if the media clock rates differ and would require different sequence number spaces to tell which payload type suffered packet loss. The RTCP sender and receiver reports can only describe one timing and sequence number space per SSRC and do not carry a payload type field. An RTP mixer would not be able to combine interleaved streams of compatible media into one stream. Carrying multiple media in one RTP session precludes: the use of different network paths or network resource allocations if appropriate; reception of a subset of the media if desired, for example just audio if video would exceed the available bandwidth; and receiver implementations that use separate processes for the different media, whereas using separate RTP sessions permits either single- or multiple-process implementations. Using a different SSRC for each medium but sending them in the same RTP session would avoid the first three problems but not the last two. 5.3 Profile-Specific modifications to the RTP header: The existing RTP data packet header is believed to be complete for the set of functions required in common across all the application classes that RTP might support. However, in keeping with the ALF design principle, the header may be tailored through modifications or additions defined in a profile specification while still allowing profile-independent monitoring and recording tools to function. The marker bit and payload type field carry profile-specific information, but they are allocated in the fixed header since many applications are expected to need them and might otherwise have to add another 32-bit word just to hold them. The octet containing these fields may be redefined by a profile to suit different requirements, for example with a more or fewer marker bits. If there are any marker bits, one should be located in the most significant bit of the octet since profile-independent monitors may be able to observe a correlation between packet loss patterns and the marker bit. Addit ional information that is required for a particular payload format, such as a video encoding, should be carried in the payload section of the packet. This might be in a header that is always present at the start of the payload section, or might be indicated by a reserved value in the data pattern. If a particular class of applications needs additional functionality independent of payload format, the profile under which those applications operate should define additional fixed fields to follow immediately after the SSRC field of the existing fixed header. Those applications will be able to quickly and directly access the additional fields while profile-independent monitors or recorders can still process the RTP packets by interpreting only the first twelve octets. If it turns out that additional functionality is needed in common across all profiles, then a new version of RTP should be defined to make a permanent change to the fixed header. 5.4 RTP header extension: An extension mechanism is provided to allow individual implementation to experiment with new payload-format-independent functions that require additional information to be carried in the RTP data packet header. This mechanism is designed so that the header extension may be ignored by other interoperating implementations that have not been extended. Note that this header extension is intended only for limited use. Most potential uses of this mechanism would be done better another way, using the methods described in the previous section. For example, a profile-specific extension to the fixed header is less expensive to process because it is not conditional nor in a variable location. Additional information is required for a particular payload format should not use this header extension but should be carried in the payload section of the packet. If the X bit in the RTP header is one, a variable-length header extension is appended to the RTP header, following the CSRC list if present. Th e RTP header extension is shown in figure 5: The header extension contains a 16-bit length field that counts the number of 32-bit words in the extension, excluding the four-octet extension header (therefore zero is a valid length). Only a single extension may be appended to the RTP data header. To allow multiple interoperating implementations to each experiment independently with different header extensions, or to allow a particular implementation to experiment with more than one type of header extension, the first 16 bits of the header extension are left open for distinguishing identifiers or parameters. The format of these 16 bits is to be defined by the profile specification under which the implementations are operating. This RTP specification does not define any header extensions itself. 5.5 Real-time Transport Control Protocol (RTCP): RTCP is a coordination protocol of RTP. It provides some tasks to increase the performance of RTP. The RTP control protocol (RTCP) is based on the periodic transmission of control packets to all participants in the session, using the same distribution mechanism as the data packets. The underlying protocol must provide multiplexing of the data and control packets, for example using separate port numbers with UDP. RTCP performs four functions: The primary function is to provide feedback on the quality of the data distribution. This is an integral part of the RTPs role as a transport protocol and is related to the flow and congestion control functions of other transport protocols. The feedback may be directly useful for control of adaptive encodings, but experiments with IP multicasting have shown that it is also critical to get feedback from the receivers to diagnose faults in the distribution. Sending reception feedback reports to all participants allows one who is observing problems to evaluate whether those problems are local or global. With a distribution mechanism like IP multicast, it is also possible for an entity such as a network service provider who is not otherwise involved in the session to receive the feedback information and act as a third-party monitor to diagnose network problems. This feedback function is performed by the RTCP sender and receiver reports. RTCP carries a persistent transport-level identifier for an RTP source called the canonical name or CNAME. Since the SSRC identifier may change if a conflict is discovered or a program is restarted, receivers require the CNAME to keep track of each participant. Receivers also require the CNAME to associate multiple data streams from a given participant in a set of related RTP sessions, for example to synchronize audio and video. The first two functions require that all participants send RTCP packets; therefore the rate must be controlled in order for RTP to scale up to a large number of participants. By having each participant send its control packets to all the others, each can independently observe the number of participants. This number is used to calculate the rate at which the packets are sent. A fourth, optional function is to convey minimal session control information, for example participant identification to be displayed in the user interface. This is most likely to be useful in loosely controlled sessions where participants enter and leave without membership control or parameter negotiation. RTCP serves as a convenient channel to reach all the participants, but it is not necessarily expected to support all the control communication requirements of an application. A higher-level session control protocol, which is beyond the scope of this document, may be needed. Functions (i)-(iii) are mandatory when RTP is used in the IP multicast environment, and are recommended for all environments. RTP application designers are advised to avoid mechanisms that can only work in unicast mode and will not scale to larger numbers. 5.6 RTCP transmission interval: RTP is designed to allow an application to scale automatically over session sizes ranging from a few participants to thousands. For example, in an audio conference the data traffic is inherently self-limiting because only one or two people will speak at a time, so with multicast distribution the data rate on any given link remains relatively constant independent of the number of participants. However, the control traffic is not self-limiting. If the reception reports from each participant were sent at a constant rate, the control traffic would grow linearly with the number of participants. Therefore, the rate must be scaled down. For each session, it is assumed that the data traffic is subject to an aggregate limit called the session bandwidth to be divided among the participants. This bandwidth might be reserved and the limit enforced by the network, or it might just be a reasonable share. The session bandwidth may be chosen based or some cost or a priori knowledge of the available network bandwidth for the session. It is somewhat independent of the media encoding, but the encoding choice may be limited by the session bandwidth. The session bandwidth parameter is expected to be supplied by a session management application when it invokes a media application, but media applications may also set a default based on the single-sender data bandwidth for the encoding selected for the session. The application may also enforce bandwidth limits based on multicast scope rules or other criteria. Bandwidth calculations for control and data traffic include lower- layer transport and network protocols (e.g., UDP and IP) since that are what the resource reservation system would need to know. The application can also be expected to know which of these protocols are in use. Link level headers a