The Mississippi River Essay Example | Topics and Well Written Essays - 1500 words

The Mississippi River - Essay Example Archaeologists use the term Mississippian to refer to the number of native Indian tribes that existed between about 750 and 1500 AD (or after) all over the Mississippi, Tennessee, and Cumberland River valleys. The Mississippian existence can be identified with a number of common characteristic traits: potteries generally ‘tempered’ with compressed ‘mussel shell’, rural-based maize cultivation, big ‘flat topped’ mounts placed in the vicinity of the town marketplace are all common features of Mississippians (Thomas, 1999, p. 151). Over the last few centuries, extensive archaeological works have been done in this region to know more about the Mississippian people. Their progress from dependence on forests to adoption of maize as a chief source of food is now linked up. Also, comparative studies between different regions forming the Mississippi, Tennessee, and Cumberland River valleys show that a common history united them and there were exchanges o f goods and art items between them. Bow and arrow were used by Mississippians. They related their agricultural vocation with religion. Mississippians worshipped a deity resembling fire-sun and travelled extensively. During the time when Mississippian tribes thrived, they use to organize large ceremonies in sites now called Cahokia, Moundville, Spiro, and Etowah. The Mississippian aristocracy was powerful with holdings of hundreds of small farmers who used to live in smaller fenced colonies and farms. A large part of eastern North America did not adopt the Mississippian culture. However, economies of all were relied on some degree to the Mississippian economy. Offspring of the great American Indian Confederacies of the American southland together with so-called Five Civilized Tribes are profoundly linked with their Mississippian heritage (Thomas, 1999, pp. 151). Cahokia is often called by the archaeologists as Mississippi City of the sun. Cahokia is one of the most important sites fo r archaeologists to understand the civilization of early Mississippians. Cahokia was the biggest city in the native North America. Situated on the extensive tidal plain that links the Mississippi river and the Missouri river, Cahokia possessed fertile soil and abundant wildlife. Around 700 AD, efficient villages were set up by late Woodlanders who depended on forests and also grew few farm products, including little maize. Cahokia was purposely situated near the main farmland belt, linked to the land and water routes and connecting the city to both nearby and faraway communities (Thomas, 1999, pp. 152, 154). According to Thomas, the more broad-based Mississippian culture evolved later, around 850 and 900 AD. Despite the fact that sedentary lifestyle of Mississippians varied distinctly from the forest-based Woodland community, it is believed that there was probably a genetic link between the two. Between 800 and 1100 AD, Mississippian people explored beyond customary Woodland-style f arming of native plants to opt for import of Mexican maize. Maize has been cultivated intensively throughout eastern North America long before, which was perhaps the reason for emergence of its more multifarious sociopolitical arrangement. Finally, the maize cultivation would be the backbone for the emerging Iroquoian federation of the Northeast, the Fort Ancient confederation beside the middle Ohio

Analysis of the Use of Tag Questions Essay Example for Free

Analysis of the Use of Tag Questions Essay Tag questions are those fragments at the end of a sentence when a person is asking to be affirmed. Instead of a statement being declarative or imperative, the use of the interrogative fragment at the end of the sentence reformulates the statement into a tag question (Akmajian 2001). Examples of variations of tag questions include â€Å"†¦, will you? †, â€Å"†¦, isn’t it? †, â€Å"†¦, okay? †, and â€Å"†¦, right? † Use of these interrogative fragments at the end of sentences are often referred to as leading questions, in that the questioner is desiring the answerer to verify what one is saying is true. In studying the use of tag questions among random groups of people of varying occupations and genders, it is interesting to note the ways in which certain tag questions are used in a wide range of settings. Men and women differ in their use of particular tag questions, as do people who are more or less familiar with one another (Lakoff, 1973). People from different cultures also use tag questions in various ways, placing emphasis on different word choices in various settings (Moore Podesva, 2009). This study aims to describe the ways in which tag questions are used in various populations and to make an assessment of the most widely used tag questions. In narrowing down the tag questions being studied, it is assumed that â€Å"okay† and â€Å"right† are the most commonly used tag questions. â€Å"Okay† is a tag question which is more open-ended and allows for the answerer to have more leeway in answering negatively. â€Å"Right† is a tag questions which is more close-ended and places more pressure on the answerer to answer affirmatively. In beginning to study linguistic patterns and collect data, it is hypothesized that the most often used tag question will be the use of the tag â€Å"okay†, with â€Å"right† being used more often by males than females. Methodology In studying the linguistic patterns of people in speech and writing, data was collected about the speakers and contextual situations, including the tag question being used, the gender of the questioner, the gender of the answerer, the familiarity of questioner and answerer, and the channel of communication. There were various situations in which the use of tag questions was identified, including discussions between men, women, elderly, adults, children, spouses, coworkers, friends, and strangers, and in informal settings, formal settings, stores, workplaces, face to face, telephone, and electronic messaging. Each noted tag question was recorded in a small notebook, collecting data on the diverse amounts of tag questions being used in a wide range of natural settings. By paying attention to nearby conversations and online messages, one is able to gather a significant amount of information about linguistic patterns, including the prominence and level of occurrence of various tag questions. It is important for linguistic researchers to be good listeners and to make careful observations of the situations they are attempting to describe. The moment in which a tag question is utilized comes very suddenly, and the good linguist has one’s ears perked for these significant moments and is able to take a virtual snapshot of the scene, including and emphasizing the use of language. In this study, 50 different random occurrences of the use of tag questions in society were collected, with significant identifiers and situational circumstances being recorded.

Investigating The Structure Of Pig Heart Physical Education Essay

Investigating The Structure Of Pig Heart Physical Education Essay Introduction There are three layers of the heart: the epicardium, myocardium and the endocardium. The heart, like a dual pump, which is to pump blood around the whole body, pick-up nutrients and oxygen, at the same time, helping eliminate deleterious wastes, such as carbon dioxide. Moreover, the heart consists of four chambers: two ventricles and two atria. The upper chambers are called atria while the lower chambers are called ventricles, they are separated by valves. Valves are one-way, see Figure 1(Lane, 2010b), hence, they play an important role in preventing the blood from flowing back. Figure 1 One Way Valve (Lane, 2010b) The left are right chambers are separated by muscular wall septum. Without this septum, blood from one chamber will be mixed up with the blood from another and be contaminated (Burnell, 2010). The ventricles have thicker muscles than the atria, they are strong enough to pump the blood out of the heart and circulate to other parts of the body.   Besides, the pressure applied on the left ventricle is greater. As a result, the walls of the left ventricle are the thickest among all the walls of chambers (Burnell, 2010). The coronary artery supply blood to heart muscles and oxygenated, it under the groove on the front the heart and it branches over the front (Lane, 2010b) The pulmonary artery can carry blood to lungs to incept oxygen. It is used to travel the short distance to lungs because large volume of blood can be passed through and oxygenated. The pulmonary artery locates d of curving out of the right ventricle (Lane, 2010b). Methodology Apparatus The material and apparatus used in the experiment: the fresh pig heart, dissecting pan, forceps, scalpels, scissors and gloves. Methods and Observations Procedure 1: External Structure (Lane, 2010a) The heart was washed and placed into a dissecting pan. The colour of heart is pink, white colour exist in the top (maybe this colour is from fatty) and with much dried blood. It can be held by two hands and approximately is 13 cm 10 cm 7 cm. The heart is about 0.25 kg. The pericardium was found a covering the membrane of heart. The pericardium was cut by a scalpel so that the pericardium could be observed. The myocardium was located below the pericardium. The pericardium is a strong membrane. Thus, it is difficult to remove this membrane. It is about 1mm and colourless. The apex was located and was pointing down. The apex is easy to find, it is pink and pointed. The front of the heart was recognized by a groove that extends from the right side of the broad end to the left of the apex. There are many veined patterns in the front of heart, judged it in this way: the major blood vessels were on the top half running down to the apex. There were four chambers in heart. The left and right atria were found. Left and right chambers are distinct and atria are upper than the ventricles. Also, the left chambers are bigger than right chamber. Blood vessels at the broad end of the heart were located. The coronary artery was found its position; the pulmonary artery was located by finger curving out of the right ventricle; and the aorta was located behind the pulmonary artery. The pulmonary veins were found at the top of the left atrium. The superior vena cava was found in top of right atrium. The coronary artery is under the groove on the front of the heart. The pulmonary artery on the right side, the aorta is behind the pulmonary artery both from the top. The diameters of holes are about 3cm. The pulmonary vein is in the left side and behind the superior vena cave. However, the inferior vena cava can not be found. Figure 2 and Figure 3 are shown the external structure (Xia, 2010). Procedure 2: Internal Anatomy (Lane, 2010a) Using scissors, the pulmonary artery was cut through. The wall of the right ventricle was cut down continually, parallel to the groove of coronary artery. It is easy to cut through and the wall of the right ventricle. The wall is about 1cm thin and very smooth. A finger was used to push open the heart, the dried blood inside the chambers was washed out. Many blood clots exist inside. The blood clots are dark and jellified. The muscular wall of right atrium was measured. The right ventricle was felt the thickness and its smooth textured lining. The muscular wall of the right atrium was measured, about 1cm. The wall is very smooth. Inferior vena cava was found in the internal right ventricle, and the lack of valves was noticed. Inferior vena cava in the inside chamber lower left, which locate in right ventricle, near apex. The valve between the right atrium and right ventricle was observed. The valve between the right atrium and right ventricle is thin and easy to break. It was not easily seen. The network of irregular muscular cords was noticed. The network of irregular muscular cords was found everywhere. The colour of them is pink and ropy. It is hard to destroy. The septum on the right side of the right ventricle was found. The septum on the right side of right ventricle is very thick about 1.5cm. Using a finger, the pulmonary artery was followed to locate the right ventricle. The pulmonary valve was found. The pulmonary valve is very thin about 1mm and not seen to be intact. Figure 3 is shown the right side of heart (Xia, 2010). Using scissors, the heart was cut on the outside of left atrium downward into the left ventricle cutting toward the apex to septum at the center groove. The heart was cleaned. The wall of the left atrium is about 2.5cm. The wall of the left ventricle is thicker, about 3 cm and hard to cut through. Jellified bloods were washed. Semi-lunar valves were found. Semi-lunar valves are consisting two valves, about 1mm and pink. Mitral valve was found. The two parts of valves were seen and about 1mm. The left ventricle was cut across toward the aorta, to expose any valves. The left ventricle is hard to cut because the wall is about 3cm. The aortic valve was found. The valve is consisted of three flaps, the shape as half-moon, about 1mm. Figure 5 is shown the left side of heart (Xia, 2010). Figure 6 is shown the internal anatomy (Xia, 2010) Result Figure 2 The Front View of Heart (Xia, 2010) Figure 3 The Rear View of Heart (Xia, 2010) Figure 4 The Right Side of Heart (Xia, 2010) Figure 5 The Left Side of Heart (Xia, 2010) Figure 6 The Internal Structure (Xia, 2010) All these figures are at the end of report in the appendix. Discussion Initially, because the structure of heart is unfamiliar, the process was done slowly, and many aspects are uncertain. In addition, before the experiment a picture of heart structure was found, during the experiment the picture was used to compare with the real heart so that identification can be more easily achieved to find structures position. However, the correct position of picture is different from position in the real heart. The reasons may the diagram is idealized, the real heart is empty and collapsed, structures lack colour contrast to distinguish. When the wall of left ventricle was cut, it is more difficult to sever than the right ventricle. During procedure 2, some muscular cords were cut and some places were undistinguishable. The wall of left ventricle is much thicker than right wall because the left ventricle did the major work. The handout suggested that watching the diastole and systole of the heart. However, this is a departed pig heart, thus, the phenomenon can not be seen. In addition, valves are very thin, when the heart is cut, valves are easily destroyed by mistake, such as the pulmonary valve is not seen to be intact. Conclusion During the experiment, the heart was examined, its external structure, each vessels characteristic and position was found and recognized. In the internal anatomy, different positions of valves were found. Dimensions of different parts of heart were measured: the size of heart, the pericardium, the diameter of vessels holes, the wall of the right ventricle and atrium, the wall of the left ventricle and atrium, the thickness of semi-lunar valves, the thickness of mitral valve, the thickness of aortic valve.

My Generation Essay -- essays research papers

My Generation   Ã‚  Ã‚  Ã‚  Ã‚  Every group receives a name, whether it is a club or organization, plants, animals or people. No matter what it is, it will receive a label so that it can be referred to easily. For instance, those born between the years 1977 and 1997 were given the title of the â€Å"Digital Generation.† This label was attained because of the widespread technology that is available to them from birth. The â€Å"Digital Generation† is not only about the Internet and technology, but is also about high values, a strong belief in self-expression and spirituality.   Ã‚  Ã‚  Ã‚  Ã‚  The values of past generations have been very self-centered. Yet â€Å"Generation D†, as it is called, believes in equal rights for all and a strong connection with family and friends. Yet they are so materialistic that the older generations see them as â€Å"floozies with credit cards.† This is one of the reasons why there are so many equal rights activists today. Never before has there been such a range of reasons to stand up for ones right. For instance, there are so many organizations to stop violence against people; race, creed, sexuality, gender, nationality, etc., are irrelevant. Today’s youth is acquainted with many different people, but they only share close connections with a select few. A person of this generation will know many people and be friendly with them, however the personally association is only present with the people that have been known for an extended period...

Electric Discharge Machining

ELECTRIC DISCHARGE MACHINING INTRODUCTION * Sometimes it is referred to as spark machining, * Its a manufacturing process whereby a desired shape is obtained using electrical discharges (sparks). * Material is removed from the workpiece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage. * One of the electrodes – ‘tool-electrode’ or ‘tool’ or ‘electrode’. * Other electrode – workpiece-electrode or ‘workpiece’. As distance between the two electrodes is reduced, the current intensity becomes greater than the strength of the dielectric (at least in some points) causing it to break. * EDM is a machining method primarily used for hard metals or those that would be very difficult to machine with traditional techniques. * EDM typically works with materials that are electrically conductive, although methods for machining insulating cer amics with EDM have been proposed. * EDM can cut intricate contours or cavities in hardened steel without the need for heat treatment to soften and re-harden them. This method can be used with any other metal or metal alloy such as titanium, hastelloy, kovar, and inconel. EDM – Working Principle * It is a process of metal removal based on the principle of material removal by an interrupted electric spark discharge between the electrode tool and the work piece. * In EDM, a potential difference is applied between the tool and workpiece. * Essential – Both tool and work material are to be conductors. * The tool and work material are immersed in a dielectric medium. * Generally kerosene or deionised water is used as the dielectric medium. A gap is maintained between the tool and the workpiece. * Depending upon the applied potential difference (50 to 450 V) and the gap between the tool and workpiece, an electric field would be established. * Generally the tool is connected to the negative terminal (cathode) of the generator and the workpiece is connected to positive terminal (anode). * The high speed electrons then impinge on the job and ions on the tool. * The kinetic energy of the electrons and ions on impact with the surface of the job and tool respectively would be converted into thermal energy or heat flux. Such intense localized heat flux leads to extreme instantaneous confined rise in temperature which would be in excess of 10,000oC. * Such localized extreme rise in temperature leads to material removal. * Material removal occurs due to instant vaporization of the material as well as due to melting. * The molten metal is not removed completely but only partially. EDM – Dielectric * In EDM, material removal mainly occurs due to thermal evaporation and melting. * As thermal processing is required to be carried out in absence of oxygen so that the process can be controlled and oxidation avoided. Oxidation often leads to poor surface conduct ivity (electrical) of the workpiece hindering further machining. * Hence, dielectric fluid should provide an oxygen free machining environment. * Further it should have enough strong dielectric resistance so that it does not breakdown electrically too easily. * But at the same time, it should ionize when electrons collide with its molecule. * Moreover, during sparking it should be thermally resistant as well. * Generally kerosene and deionised water is used as dielectric fluid in EDM. Electric Discharge Machining ELECTRIC DISCHARGE MACHINING INTRODUCTION * Sometimes it is referred to as spark machining, * Its a manufacturing process whereby a desired shape is obtained using electrical discharges (sparks). * Material is removed from the workpiece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage. * One of the electrodes – ‘tool-electrode’ or ‘tool’ or ‘electrode’. * Other electrode – workpiece-electrode or ‘workpiece’. As distance between the two electrodes is reduced, the current intensity becomes greater than the strength of the dielectric (at least in some points) causing it to break. * EDM is a machining method primarily used for hard metals or those that would be very difficult to machine with traditional techniques. * EDM typically works with materials that are electrically conductive, although methods for machining insulating cer amics with EDM have been proposed. * EDM can cut intricate contours or cavities in hardened steel without the need for heat treatment to soften and re-harden them. This method can be used with any other metal or metal alloy such as titanium, hastelloy, kovar, and inconel. EDM – Working Principle * It is a process of metal removal based on the principle of material removal by an interrupted electric spark discharge between the electrode tool and the work piece. * In EDM, a potential difference is applied between the tool and workpiece. * Essential – Both tool and work material are to be conductors. * The tool and work material are immersed in a dielectric medium. * Generally kerosene or deionised water is used as the dielectric medium. A gap is maintained between the tool and the workpiece. * Depending upon the applied potential difference (50 to 450 V) and the gap between the tool and workpiece, an electric field would be established. * Generally the tool is connected to the negative terminal (cathode) of the generator and the workpiece is connected to positive terminal (anode). * The high speed electrons then impinge on the job and ions on the tool. * The kinetic energy of the electrons and ions on impact with the surface of the job and tool respectively would be converted into thermal energy or heat flux. Such intense localized heat flux leads to extreme instantaneous confined rise in temperature which would be in excess of 10,000oC. * Such localized extreme rise in temperature leads to material removal. * Material removal occurs due to instant vaporization of the material as well as due to melting. * The molten metal is not removed completely but only partially. EDM – Dielectric * In EDM, material removal mainly occurs due to thermal evaporation and melting. * As thermal processing is required to be carried out in absence of oxygen so that the process can be controlled and oxidation avoided. Oxidation often leads to poor surface conduct ivity (electrical) of the workpiece hindering further machining. * Hence, dielectric fluid should provide an oxygen free machining environment. * Further it should have enough strong dielectric resistance so that it does not breakdown electrically too easily. * But at the same time, it should ionize when electrons collide with its molecule. * Moreover, during sparking it should be thermally resistant as well. * Generally kerosene and deionised water is used as dielectric fluid in EDM.

Life and Art of Charles Demuth, Precisionist Painter

Life and Art of Charles Demuth, Precisionist Painter Charles Demuth (November 8, 1883 – October 23, 1935) was an American Modernist painter best known for his use of watercolor to portray the industrial and natural landscapes of his Pennsylvania hometown. His paintings emerged out of the abstract Cubist style and ultimately led to a new movement called Precisionism. Fast Facts: Charles Demuth Occupation: Artist (painter)Known For: Abstract Cubist style and involvement in the Precisionist movementBorn:  November  8, 1883 in Lancaster, PennsylvaniaDied:  October  23, 1935  in Lancaster, PennsylvaniaEducation: Franklin Marshall College and Pennsylvania Academy of Fine Arts Selected Paintings: My Egypt (1927);  I Saw the Figure 5 in Gold (1928);  Roofs and Steeple (1921) Early Years and Training Demuth was born and raised in Lancaster, Pennsylvania, whose urban landscape and emerging industrial setting served as an inspiration for several of his paintings. Demuth was ill and often bedridden as a child. During those times, his mother kept him entertained by providing him with watercolor supplies, thus giving the young Demuth his start in the arts. He eventually portrayed the agricultural portraits he knew best: flowers, fruit and vegetables. Demuth graduated from Franklin Marshall Academy, which later become Franklin Marshall College, in Lancaster. He also studied at Pennsylvania Academy of Fine Arts in Philadelphia and in the arts scenes of New York, Provincetown, and Bermuda. He socialized with and was photographed by Alfred Stieglitz, who was working at the time to organize exhibits of modernist art for his American Place Gallery in New York. Demuth spent time studying art in Paris, where he was part of the avant garde scene. His contemporaries included  Georgia OKeeffe, Marcel DuChamp, Marsden Hartley and Alfred Steiglitz. Painting in His Own Backyard Though he traveled to and was influence by exotic locales, Demuth painted most of his art in the second-story studio of his Lancaster home, which overlooked a garden. In the painting My Egypt (1927), Demuth depicted a grain elevator, a massive structure used to store the harvest, next to row house rooftops. Both structures are common in the rich agriculture economy and historic urban setting of Lancaster County. Like many of his contemporaries in the arts, Demuth was fascinated with Americas landscape, which was being altered at the hands of industrialism. He saw firsthand the smokestacks and water towers in cities such as Philadelphia, New York and Paris. He painted those skylines and contrasted them with grain elevators that were common in his hometown. The Precisionist Style The movement to which Demuth belonged, Precisionism, stressed visual order and clarity in the visual arts and combined those facets with a celebration of technology and expression of speed through dynamic compositions, according to the Metropolitan Museum of Art. Demuth and his fellow Precisionists painted distinctly American landscapes in an intentional move to distance themselves from European artists. Demuths most famous work is a 1928 oil painting called I Saw the Figure 5 in Gold, which has been described as a masterpiece of the Precisionism movement. The painting was inspired by the poem The Great Figure by William Carlos Williams. Williams, who had met Demuth at Philadelphias Pennsylvania Academy of Fine Arts, wrote the famous poem after watching a fire engine speed by on a Manhattan street. Demuth tried to capture the following lines in his painting: Among the rainand lightsI saw the figure 5in goldon a redfiretruckmovingtenseunheededto gong clangssiren howlsand wheels rumblingthrough the dark city I Saw the Figure 5 in Gold, as well as other Demuth paintings, served as an influence on commercial artists who later designed movie posters and book covers. Later Life and Legacy Demuth was diagnosed with diabetes at a relatively young age, and the condition made him weak before he turned 40. He spent his final years confined to his mothers home in Lancaster, away from his fellow artists working in Paris, and died at age 51. Demuth made a significant impact on the art world with the development of the Precisionist movement. His emphasis on geometrical forms  and industrial  subject matter came to exemplify the ideals of Precisionism. Sources Further Reading Johnson, Ken. â€Å"Chimneys and Towers: Charles Demuths Late Paintings of Lancaster - Art - Review.† The New York Times, The New York Times, 27 Feb. 2008, www.nytimes.com/2008/02/27/arts/design/27demu.html.Murphy, Jessica. â€Å"Precisionism.† In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000–. metmuseum.org/toah/hd/prec/hd_prec.htmSmith, Roberta. â€Å"Precisionism And a Few Of Its Friends.† The New York Times, The New York Times, 11 Dec. 1994, www.nytimes.com/1994/12/11/arts/art-view-precisionism-and-a-few-of-its-friends.html?ftay.