Mexican War and the Spanish American War Essay Example for Free

Mexican War and the Spanish American War Essay Both the Mexican War and the Spanish War were a result of unfair treatment against weaker nations. The origins of the Mexican War lay with the United States and its expansionistic policies. Most Americans believed they had a divine right to bring their culture among others, because they were superior. This belief was put forth by Manifest Destiny, which had been circulating around the United States for a long time. The ignorance possessed by the Americans show no courtesy toward the Mexicans. Under the administration of President Polk, America adopted an aggressive expansion policy that often ignored many inferior countries. In 1492, it was Spain whom sailed across the Ocean and colonized the Amerindian nations of the Western Hemisphere. At its greatest extent, the empire that resulted from this exploration extended from Virginia on the eastern coast of the United States south to Tierra del Fuego at the tip of South America excluding Brazil and westward to California and Alaska. The ambitious United States paid no attention to Spain and aggressively sought more territory and influence in Cuba, the Philippines, and Puerto Rico. The war started when the United States declared war on Spain after the sinking of an American vessel (Battleship Main) in Havana harbor on February 15, 1898. They war ended on December 10, 1898 after the unfair Treaty of Paris, in which Spain lost all of its overseas possessions including Cuba, Puerto Rico, the Philippine Islands, Guam, and many others. Both the Mexican War and the Spanish American War were a direct result in the abusive ways of superior power and influence. Manifest Destiny was more encouraged when Polk became President. He was elected president because of his strong support in bringing Oregon and Texas into the Union. President Polk was clearly the antagonist when he sent troops under General Zachary Taylor into land that Mexico held sovereignty, sparking a war. Polk now drafted a message to Congress: Mexico had passed the boundary of the United States, had invaded our territory and shed American blood on American soil. Whether the Mexicans had fired the first shot or the Americans, whether the armies were on Mexican territory or American territory, Polk got his war. Despite the plea of innocence, Mexico cannot escape blame for the war. Mexico never had a strong centralized government to negotiate with a foreign state. Mexico was never even  successful in governing themselves for the time being. Mexico was on the verge of bankruptcy and their army was inadequately trained and equipped. The country was awash with political turmoil throughout the war, indeed, throughout the century, making it near impossible for them to ever conduct a sound defense of the country. Nevertheless, the United States, as a superior nation under Polks Presidency assumed an aggressive war like attitude toward Mexico without consideration of the Mexican stance. The conflict between the Spanish and Americans grew dramatically when General Valeriano Weyler began implementing a policy of Reconcentration that moved the population into central locations guarded by Spanish troops and placed the entire country of Cuba under martial law in February 1896. The American government was once again looking to exploit their defenseless neighbors and gain more influence in the countries. The main targets were Cuba, Puerto Rico, and the Philippines. Cuba was the first to initiate its own struggle for independence from Spain. America, being the closest superior power intervened in Cubas affairs. The Philippines were also growing intolerable to Spanish rule, and the United States took interest in the Philippines. Following its declaration of war against Spain issued on April 25, 1898, the United States added the Teller Amendment asserting that it would not attempt to exercise hegemony over Cuba. Under Commodore George Dewy at the Battle of Manila Bay on May 1st, the Spanish fleet under Rear Admiral Patricio Montojo was destroyed. The most disrespect followed the signing of the Treaty of Paris when Spain lost all of its overseas possessions. The superior powers, such as the United States, are always looking to profit themselves. During the Mexican war and the Spanish-American War, the dominance and ethnocentric ideals that America held flourished in many un-called-for, disrespectful disputes. The aggressive stance the troops held under Zachary Taylor under the orders of President Polk did not give room for negotiation. If the United States did not get what they wanted, they would insist by force, not by allowing the inferior nation in their eyes to make suggestions that regard their country and dignity. Both the Mexican War and the Spanish-American War resulted because of the unfair and unjust treatment that the United States held in their so-called foreign policy. Hispanic Division Library of Congress http://lcweb.loc.gov/rr/hispanic/1898/intro.html A People A Nation 6th Edition The Mexican American War Memorial Homepage -from UMAN The Mexican American War Memorial Homepage -from UMAN Hispanic Division Library of Congress http://lcweb.loc.gov/rr/hispanic/1898/intro.html Hispanic Division Library of Congress http://lcweb.loc.gov/rr/hispanic/1898/intro.html

A Cultural Review of Germany in the 1940’s According to Essay Example for Free

A Cultural Review of Germany in the 1940’s According to Essay It has been said, to understand the present a person must know and understand the past. Focusing on that quote specifically to understanding the past is what The Diary of Anne Frank allows the reader to do. There are many different cultures around the world and many cultures within cultures. Looking specifically at Germany in the time period of the 1940’s, the reader can see that there in fact is a culture within in a culture. The great thing about this piece of literature is that it is the actual person in the culture writing what is going on during that time frame. The Diary of Anne Frank lets the reader dive into a part of history that the culture was different from any other and experience what it was like to be a Jew in the 1940’s in Western Europe. It is sort of ironic how during that time period there were people living in peace and people living in turmoil. This diary only tells about her experience while she is hiding out, but it also gives reference to what is going on outside her family’s hide out. So from that point of view the reader can get the view of what the culture was like while Jewish people were hiding out and what is was like to be taken away and put in a concentration camp. Living in peace may mean how the German people are living because they do not have to face persecution from the government or it could mean how the Jewish that are living in hideouts are at peace because they have not been sent to a concentration camp yet. On the other hand living in turmoil can mean that the Jewish people are living fear of being caught and taken to a concentration camp and that the people that are already in the camps are already in turmoil. When it is said that someone is living in fear means that they are fearful because something may happen to them. In this case it is the fact that they could be taken away from their families if they are caught in hiding. In Anne Frank’s case, she is afraid because she wants to be an actress and those dreams may never come true. It is also the fear of not knowing. Being in suspense of not knowing what is going to happen is sometimes worse that what actually is going to happen. While Jewish people are living in hideouts there is no doubt they are living in fear. The reader can tell that in fact all of the residents with Anne Frank are living in fear because every time something happens they assume that it is the Green Police coming to get them. Living in the concentration camps is living in hope. Not knowing what is going on outside the fence of the camp is left up to the imagination of the person looking out it. Sometimes the only way to move on in life, especially living in a concentration camp, is to hope for something better. Just like when it comes to religion, people believe that there is a higher power. It gives them hope to move on to the next day because if there was no higher power to believe in and give a cause for living then in fact what would be the reason to live. The reader can see this evidence because the father of Anne Frank tells everyone that they do not have to live in fear anymore and they can live in hope that the war will end. It may be far fetched to say that freedom was still available to the Jewish people. But while hiding out there was still some freedom that they could enjoy. Meal time was something that everyone looked forward to during the day. Just being able to eat was such a moral booster. Even though it was just maybe a potato and bread, it still had an effect that gave them strength to move on to the next day. Life in the German concentration camps was equally unbearable. After arriving, the Jews found the camps weren’t much better than the railway’s cattle cars. Row after row of barrack-style houses stood in the center of these camps. Inside each barrack there was little more than beds, three or four high with little space between them and hardly any room in which to move. There was little food and water there too. Thousands in the camps died from starvation, disease, and exposure to the elements. Others were shot at the whim of the Nazis guards. Those Jews that worked had their lives spared but were fed only enough to keep them alive. No one knows for sure how many children were killed but it is estimated at between 1. 2 and 1. 5 million. The children that survived did so because they were hidden in homes, basements and convents or lived with Christian families who concealed their identities. By the end of the war six million Jews had been killed in one way or another inside and outside concentration camps across Europe. Never in human history had so many been killed because of who they were. Jews not immediately selected for extermination faced a living death in the concentration camp, which also included non-Jewish inmates, many of them opponents of the Nazi regime. The SS, who ran the camps, took sadistic pleasure in humiliating and brutalizing their helpless Jewish victims. They get up at 3 am. They have to dress quickly, and make the bed so that it looks like a matchbox. For the slightest irregularity in bed-making the punishment was 25 lashes, after which it was impossible to lie or sit for a whole month. Everyone had to leave the barracks immediately. Outside it is still dark or else the moon is shining. People are trembling because of lack of sleep and the cold. In order to warm up a bit, groups of ten to twenty people stand together, back to back so as to rub against each other. There was what was called a wash-room, where everyone in the camp was supposed to wash. There were only a few faucets and there were 4,500 people in that section. Of course there was neither soap nor towel or even a hand-kerchief, so that washing was theoretical rather than practical. In one day, a person there came a lowly person indeed. They used to get half a liter of black, bitter coffee. That was all they got for what was called breakfast. At 6 a. m. a headcount and they all had to stand at attention, in fives, according to the barracks, of which there were 22 in each section. They stood there until the SS men had satisfied their game-playing instincts by humorous orders to take off and put on caps. Then they received their report, and counted us. After the headcount work started. They went in groups some to build railway tracks or a road, some to the quarries to carry stones or coal, some to take out manure, or for potato-digging. latrine-cleaning, barracks or sewer repairs. All this took place inside the camp enclosure. During work the SS men beat up the prisoners mercilessly, inhumanly and for no reason. They were like wild beasts and, having found their victim, ordered them to present their backside, and beat them with a stick or a whip, usually until the stick broke. The victims screamed only after the first blows, afterwards they fell unconscious and the SS men then kicked at the ribs, the face, at the most sensitive parts of a person’s body, and then, finally convinced that the victim was at the end of their strength, The SS would order another Jew to pour one pail of water after the other over the beaten person until they woke and got up. A favorite sport of the SS men was to make a boxing sack out of a Jew. This was done in the following way: Two Jews were stood up, one being forced to hold the other by the collar, and an SS man trained giving him a knock-out. Of course, after the first blow, the poor victim was likely to fall, and this was prevented by the other Jew holding him up. After the fact, Hitlerite murderer had trained in this way for 15 minutes, and only after the poor victim was completely shattered, covered in blood, his teeth knocked out, his nose broken, his eyes hit, and they released him and ordered a doctor to treat his wounds. That was their way of taking care and being generous. Another customary SS habit was to kick a Jew with a heavy boot. The Jew was forced to stand to attention, and all the while the SS man kicked him until he broke some bones. People who stood near enough to such a victim often heard the breaking of the bones. The pain was so terrible that people, having undergone that treatment, died in agony. Apart from the SS men there were other expert hangmen. These were the so-called Capos. The name was an abbreviation for barracks police. The Capos were German criminals who were also camp inmates. However, although they belonged to us, they were privileged. They had a special, better barracks of their own; they had better food, better, almost normal clothes. They wore special red or green riding pants, high leather boots, and fulfilled the functions of camp guards. They were worse even than the SS men. In each section stood a gallows, for being late for the head count, or similar crimes, the camp elder hanged the offenders. Work was actually unproductive, and its purpose was exhaustion and torture. At twelve noon there was a break for a meal. Standing in line, we received half a liter of soup each. Usually it was cabbage soup, or some other watery liquid, with-out fats, tasteless. That was lunch. It was eaten in all weather under the open sky, never in the barracks. No spoons were allowed, though wooden spoons lay on each bunk probably for show, for Red Cross committees. One had to drink the soup out of the bowl and lick it like a dog. From 1 p. m. till 6 p. m. there was work again. I must emphasize that if we were lucky we got a 12 oclock meal. There were days of punishment when lunch was given together with the evening meal, and it was cold and sour, so that our stomach was empty for a whole day. Afternoon work was the same: blows, and blows again. Until 6 p.m. At six there was the evening headcount. Again we were forced to stand at attention. Counting, receiving the report. Usually we were left standing at attention for an hour or two, while some prisoners were called up for punishment parade-they were those who in the Germans eyes had transgressed in some way during the day, or had not been punctilious in their performance. They were stripped naked publicly, laid out on specially constructed benches, and whipped with twenty-five or fifty lashes. The brutal beating and the heart-rending cries all this the prisoners had to watch and hear. In conclusion, the reader can see that life, even though hard, was easier in the hideouts than it was in the concentration camps. Even if everything was still the same except the physical abuse then life would still be easier in the concentration camp. The Diary of Anne Frank gives us great insight to life while hiding out. Unfortunately she was unable to give us an account for the camps because she eventually died before the camps were liberated. But the saying, to understand the present a person must know and understand the past, is really true in these events. Hopefully for some culture history will not repeat itself.

Differences in Grid and Air Gap Techniques

Differences in Grid and Air Gap Techniques Introduction In this chapter, a literature review was carried out so that adequate information about the differences in grid and air-gap technique could be gathered with emphasis on why these techniques are important in plain radiography of the lateral hip. These two techniques will be analysed to explain better the acquisition of the image. Both techniques will be compared and their advantages and disadvantages discussed. This was done by means of radiography books and journals. Where, possible primary sources of information were chosen. However, original studies could not always be obtained and secondary sources had to be considered. The use of the internet was also important as it served as a source for and access to relevant articles. Related literature was mainly sourced using the online data bases of EBSCO ®, CINHAL ® and Pubmed ® as well as the Institute of Health Cares library and facilities. Image quality Image quality refers to the ability to view the anatomical structure under study with precision and which makes it possible to identify and spot any abnormalities (Bushong, 2008). The quality of the image depends on several physical and physiological factors and this makes it hard to measure. Image quality; Is defined in radiological terminology as the relationship between the structures of a test sample to be irradiated with x-rays and the parameters of its visualisation (Hertrich, 2005, pg.244) According to Bushong (2008), the most important factors that improve or degrade image quality are contrast resolution, spatial resolution, noise and artefacts. Image quality cannot be measured in a precise way since the quality of radiographs is hard to define (Bushong, 2008). In digital radiography (DR) the image quality depends on a number of characteristics that can change the viewing experience. One of these factors is frequency, which is a measure of the total amount of contrast within the image. This characteristic depends on the raw data (x-ray energy) that the imaging detector absorbs. The frequency of the image is represented by different grey scale levels that show the density of a particular part of the anatomical structure. This is how contrast is affected. A high contrast image has high frequency due to the amount of x-ray photons absorbed (Carlton Adler, 2006). Image quality is also subjective and depends on the viewer (Sherer et al., 2006). Different people may need to alter the quality of the image by increasing or reducing the contrast or by changing the sharpness of the image depending on their individual visual abilities (Dendy Heaton, 2003). Dendy and Heaton (2003) argue that image quality also depends on the display system and the way the image is produced. The authors further argue that room lighting also affects image quality and might also diminish image quality. Image contrast Image contrast refers to the difference in densities between adjacent anatomical structures. The amount of contrast produced on an image depends on the structural characteristic of the anatomical part of the body as well as the characteristics of the x-ray beam when it penetrates the patients body. Contrast depends on the attenuations within the patients body due to different densities in various parts of the body. The higher the difference in densities, the higher is the contrast (Sherer et al., 2006). However, small changes in densities of structures would not be detected on a high contrast image since high contrast does not have a great enough exposure latitude to give several shades of grey in the image (Bushong, 2008). This means that having high contrast in an image does not necessarily mean that it is optimal for every radiographic examination. Having low contrast means that better contrast resolution is produced and this gives the viewer the ability to differentiate between a natomical structures that have similar densities. This is why contrast is a very crucial factor in image quality (Oakley, 2003). Scattered radiation affects image contrast and the characteristics of the receptor and display system. The anatomical detail and contrast of small anatomical structures may also be reduced due to image blurring (Carlton Adler, 2006). Noise Noise affects the images contrast resolution and the detail seen in the image. Like audio noise and video noise, radiographic noise is caused by weak signals in areas of the image (Oakley, 2003). The lower the noise the better the contrast resolution and so image quality is better. According to Bushong (2008), there are four main components that affect radiographic noise. These are graininess, structure mottle, quantum mottle and scatter radiation. Graininess and structure mottle cannot be controlled by the radiographer since they are dependent on the image receptor. However, the radiographer can use several techniques and exposure factors to improve image quality and reduce the noise as much as possible depending on the subject under examination. Penetration energy of the x-ray photons (kV) can be increased in subjects that are obese and that are having thick areas of their bodies irradiated. Quantum mottle is also a very important characteristic in defining noise. Bushong (2008) ex plains that quantum mottle depends on the amounts of x-rays that are exposed and absorbed by the image detector. When few x-rays react with the receptor the resultant image will appear mottled. However, when more x-rays are absorbed by the detector, the image will appear smooth. Noise can be calculated by measuring the signal-to noise ratio of the image (Bushong, 2008). If not enough x-ray photons reach the detector, the image is said to be under-exposed, resulting in a low signal-to-noise ratio. However, a high signal-to-noise ratio is achieved if the right radiographic technique is used with the right exposure factors (Bushong, 2008). Spatial Resolution Spatial resolution is a term used in imaging that refers to the resolution of a radiograph. Having a high resolution means that more detail can be seen and detected on the image. Spatial resolution is a very important performance indicator in radiography. Quality control phantoms are used to check the spatial resolution and contrast of an imaging system. Spatial resolution relies on spatial frequency and this quantity could be calculated by seeing the number of line pairs per millimetre (Lp/mm). These line pairs are dark and white lines that are used to assess the resolution of an image. Detail is very important in radiography since outlines of tissues, organs and specific pathologies need to be sharp and detailed. High spatial resolution is also important when assessing for subtle fractures like scaphoid fractures which could easily be missed if the radiograph is not sharp enough (Bushong, 2008). Scatter Radiation When x-ray irradiation encounters matter, some photons pass unimpeded reaching the image receptor whereas other photons are completely absorbed since the energy of the primary x-ray beam is deposited within the atoms comprising the tissue. This absorption interaction of x-ray photons with matter is known as the photoelectric effect (Fauber, et al, 2009). This photoelectric effect is dependent on the matter and its effect decreases rapidly with increasing photon energy (Dendy Heaton 2003). Scatter radiation is made up of photons that are not absorbed but instead lose their energy during interactions with the atoms making up the tissue (Fauber, et al, 2009). This scattering effect is known as the Compton effect (Carlton and Adler, 2006). This happens when the incoming photon interacts with matter and loses energy. This will make the photon change direction and it may leave the anatomic part to interact with the image receptor (Fauber et al, 2009). Scattered low- photon energy reduces the contrast on the final radiograph and is also highly hazardous for patients and staff due to its changed direction and low energy from the primary beam (Dendy Heaton, 2003). Scatter Reduction As explained above, scatter radiation is produced during a Compton interaction in which a primary photon interacts with an atom of the patients body and loses its speed and direction. Scatter is produced mainly in the patient due to the variable attenuation and densities of the different organs in the body and this could be controlled by using anti-scatter techniques and the right exposure factors. Consequently the radiographer should use the adequate technique and exposure factors to reduce the radiation produced within the patients body. Carlton and Adler (2006) argue that when the energy of the primary beam is increased there is a higher chance for the photons to undergo the Compton interaction. This means that the higher the energy given to the photons (kV) the more likely it is that there is Compton interaction with the bodys atoms, therefore creating more scatter radiation and a decline in radiographic contrast (Bushong, 2008; Carlton Adler, 2006). However, Shah, Hassan Newma n (1996) think otherwise. In their study they stressed the effectiveness of anti-scatter techniques on image contrast and concluded that the influence of kV on scatter production is small. The authors further stated that the improvement in contrast that occurs when the kV is lowered is usually due to an increased subject contrast since less scatter reaches the film. Carlton and Adler (2006) also gave importance to the size of the area of body being irradiated. They suggested that by decreasing the area of irradiation as well as applying compression, scatter radiation reaching the detector could be significantly reduced. Using this technique Shah, Hassan and Newman (1996) noted a decrease in the dose area product (DAP) when decreasing the area of irradiation, therefore lowering the risk of increasing patient dose. Anti-scatter techniques Anti-scatter techniques are radiographic techniques that make use of devices or applications such as grids and air gaps so that scatter radiation is absorbed or deviated from reaching the image detector. These anti-scatter techniques help in reducing patient dose as well as improving the quality of the radiographic image. The two main techniques relevant with this study are explained and analysed in the following sub-sections. Grid Technique Grids are used in radiography to protect the image detector from scatter radiation. Scatter radiation degrades the quality of the image and may lead to loss of anatomical detail and information (Sherer et al., 2006). Anti-scatter grids are made up of parallel radio opaque strips with a low-attenuation material interspacing the strips (Sherer et al., 2006). The most commonly used interspaced materials are aluminium and carbon fibre (Court Yamazaki, 2004). The main function of these anti-scatter grids is contrast improvement. According to Carlton Adler (2006), the most effective way to see how well a grid is performing is by measuring the contrast improvement factor. The contrast improvement factor measures the ability of a grid to improve contrast. This factor is affected by the volume of tissue irradiated and by the kV. If the amount of scatter radiation increases, the contrast of the image will be reduced, therefore reducing the contrast improvement factor. This is calculated usin g the following formula: K= Radiographic Contrast with the grid/Radiographic contrast without the grid (Carlton Adler, 2006, pg.263) The higher the contrast improvement factor the higher is the contrast improvement. However, Court and Yamazaki (2004) argue that since contrast can be digitally altered in digital radiography, it is best to calculate the signal-to-noise ratio (SNR) of the image. This is especially useful in cases where there is low object contrast. The interspaced material separating the lead grid lines is also very important in monitoring the functionality of a grid. In the study performed by Court and Yamazaki (2004) it was concluded that aluminium has a higher atomic number than carbon fibre and so it absorbs more low energy scatter radiation. However, aluminium also absorbs some of the primary photons therefore increasing patient dose. Alternatively, carbon fibre absorbs less primary radiation than aluminium (Court Yamazaki, 2004). Grid ratio is also an important factor to consider in improving image quality especially image contrast. The grid ratio is obtained by dividing the height of the strips by the strip separation. As the grid ratio affects the rate of scatter to that reaching the detector it is instrumental in improving image contrast (Dendy Heaton, 2003). There are principally two types of grids, linear grids (parallel grids) and focused linear grids (Fauber, 2009). Both types have their own advantages and disadvantages. Parallel grids are made up of linear lead strips with low-density material interspacing them and are parallel to each other. This variety of grids produces grid cut-off at lateral edges since they do not coincide with the oblique divergences of the beam (Dendy Heaton, 2003; Fauber, 2009). It is also essential that these grids are positioned correctly, perpendicular to the central ray of the primary beam. If this is done incorrectly, there will be grid cut-off and the lead strips will absorb a lot of the primary beam which will show up on the image (Dendy Heaton, 2003). This will result in image deterioration and in the patient receiving an extra dose of radiation when repeating the exposure. The focused grids, however, are designed in such a way that it allows the lead strips to be gradually angled moving away from t he central axis. Although these grids are designed to eliminate the cut-off on the lateral sides, they still have to be used at a specific focus to image distance (FID) depending on the type of grid being used (Dendy Heaton, 2003). Although grids are used to improve image contrast and reduce scatter reaching the detector, this is at the expense of a high radiation dose to the patient. This happens because the mAs has to be increased when using the grid. This is necessary in order to compensate the primary beam photons absorbed by the grid (Carlton Adler, 2006). Air-gap Technique The air gap technique is an alternative technique used to reduce the amount of scatter reaching the detector. By employing an air-gap technique between the patient and the image detector, the energy of the scattered photons decreases especially in the first tens of centimetres due to the large divergence of the beam (Ball Price, 1995). The primary radiation is not affected or reduced, since at this stage the primary beam is almost parallel to the detector (Ball Price, 1995). When the air-gap technique is used, the object to image distance (OID) is increased, which may produce some magnification (Sherer et al., 2006). Anti-scatter techniques are important in reducing low energy radiation reaching the detectors. However, the primary beam should not be deflected or disrupted so that the image acquisition and image quality is not affected (Fauber, 2009).When the grid technique is employed, the grid lines are unable to discriminate between the primary radiation and the scattered radiation and so this could lead to grid cut-off and grid lines may appear on the image (Maynard, 1981). Maynard (1981) argues that with the use of an air-gap the image quality and diagnostic quality of many projections improves. A study by Karoll et al. (1985) analysed the patient dose when the air-gap was employed compared to when the grid was used. In this study the air gap was employed in a digital subtraction examination. Karoll et al. (1985) reported that by using the air gap technique the mA could be lowered without losing spatial resolution. The results of this study were remarkable as the air gap technique allowed 25% to 88% reduction on the mA without increasing the kV or the time of exposure (Karoll et al., 1985). This meant that patient dose was reduced since the mA was lowered and so the patient was irradiated less. Although this study is 25 years old, it is still valid since in direct digital radiography, windowing has given the radiographer the possibility to reduce the exposure factors to a certain limit while still obtaining a good diagnostic image. This means that patient dose could be lowered. Both grid and air-gap technique were studied and compared to assess patient dose by Kottomasu and Kulms (1997). The authors concluded that the air-gap improves musculoskeletal digital imaging without an increase in skin entrance dose. According to Kottomasu and Kulms (1997), this happened since the scattered photons had less energy once diverged by the patient; they were deflected and did not have enough energy to reach the image detector (Kottomasu Kulms, 1997). Barall (2004) also suggested that when employing the air-gap technique the radiographer should apply inverse square law by increasing the SID and applying tighter collimation. This will ensure the highest decrease in patient dose possible (Barall, 2004). The increase in SID could enable a better use of the air gap while reducing magnification by keeping the source to object distant (OID) constant. In relation to the horizontal beam lateral hip projection, there is a reduction in dose and a good diagnostic resultant image wh en compared with the grid technique (Barall, 2004). Trimble (2000) concluded that imaging the thoracic spine without a grid was possible in children and adults of small size. In this study a significant dose reduction was noted and therefore on this basis, imaging the hip laterally using a horizontal beam and applying the air-gap technique instead of the grid may also result in a reduction of patient dose as opposed to using the grid technique. Digital radiography Radiography has been revolutionised and developed throughout the years from screen film (SF) radiography a high quality digital system has evolved (Oakley, 2003). With the introduction of digital imaging systems, image quality characteristics have improved. The process of image formation in DR is similar as in SF. The image is first generated, then processed, archived and presented. Instead of films, DR uses detectors which when exposed to x-ray radiation absorb this irradiated energy which is then transformed into electrical charges, recorded, digitized and configured into different grey scales (Dendy Heaton, 2003). The grey scales presented on the produced image represent the amount of x-ray photons absorbed by the detector. A big advantage in digital radiography is image manipulation post-processing. While viewing the image, the radiographer can zoom in or out, change the greyscale as well as use measuring tools. Another great advantage of DR over SF is that images can be stored safely and archived. This solves the problem of films being lost and enables future reference of the images (Carlton Adler, 2006). There are two types of digital imaging systems: computed radiography (CR) and direct digital radiography (DR). In computed radiography imaging plates containing photostimuable crystals are used, which absorb the x-ray energy and store it temporarily (Kà ¶rner et al., 2007). Processing involves scanning the detective layer pixel by pixel using a high energy laser-beam of a specific wave-length. Since the exposed photon energies are only stored temporarily in the detective layer, the read-out process should start immediately after exposure. This is mainly because the amount of energy stored in these crystals decreases over time. Although this is a big step from screen-film (SF), spatial resolution in CR may decrease if viewing monitors are not of the appropriate resolution (Kà ¶rner et al., 2007). Direct digital radiographic systems use a photoconductor directly converting x-ray photons to electrical charges, once the photons are absorbed. The most common material used as a photoconductor in industry is amorphous selenium. This material has a high intrinsic spatial resolution. However, the material of the detector does not affect the pixel size, matrix and spatial resolution of the detector (Dendy Heaton, 2003). These are affected by recording and read out devices used. Therefore image processing in DR is as important as in SF and CR. In DR image processing is used primarily to improve the image quality by removing technical artefacts, optimising the contrast and reducing the noise (Dendy Heaton, 2003). Radiation Dose The transition from SF to DR has also changed the radiation dose that the patient gets from an x-ray exposure. Radiation dose is the amount of radiation absorbed by the patient due to a radiation exposure (Carlton Adler, 2006). In SF radiography the dynamic range of the receptor (film) is relatively low and so it only detects specific exposures that lie within its parameters. However, in DR the digital receptor can detect a wide range of exposures. This means that a slightly underexposed or overexposed image is acceptable since image quality can be altered using windowing. Therefore in DR the radiation dose could be kept relatively low when compared to SF while still producing a good diagnostic image. This could also work the other way when patients are overexposed to radiation due to the wide dynamic range of the receptors. The ALARA concept is based on the theory that there is no safe dose of radiation using any kind of irradiation or radioactive material (The Ionising Radiation [ Medical Exposure] Regulations, 2000/2007 The Medical Exposure Directive 97/43/Euratom). In this way individuals internal and external exposure to radiation is kept to a minimum. This principle does not only address radiation used in medicine but also social, technical and economic considerations of use of radiation. This principle also takes into consideration the time of exposure of radiation, filtration, and appropriate materials selected to minimise radioactivity depositing on surfaces. This also ensures the safe disposal of materials containing radioactivity such as needles used in nuclear medicine (The Ionising Radiation [Medical Exposure] Regulations, 2000/2007, The Medical Exposure Directive 97/43/Euratom). The use of ionising radiation should be monitored and used carefully to ensure as low a dose exposure as is reasonably achievable to the patient while at the same time producing an image of high diagnostic quality. Relative Literature The latest literature reviewed in relation to this dissertation was that of Flinthman (2006) who assessed thirty-five horizontal beam lateral hip radiographs for image quality. Nineteen of the cases were performed using the air-gap technique whereas sixteen using the grid technique. Several radiologists and radiographers were asked to evaluate the images. It was found that the air-gap was of higher image quality than the grid technique (Flinthman, 2006). In Flinthmans study several persons were asked to evaluate an uneven number of cases that were meant to be compared regarding the technique used to obtain the radiographs. According to Flinthman (2006) it is more important to have a small group of people evaluating the radiographs. This is because the results could be more specific and more reliable (Flinthman, 2006). A limitation of this study is that Flinthman (2006) did not use the same subjects in both techniques to achieve his results and so it is harder to attain valid and conc lusive results that could be applied in a clinical setting. A similar study comparing the grid and air-gap technique was conducted by Persliden and Carlsson (1997). Persliden and Carlsson (1997) studied scatter reduction using the air-gap and the grid technique. This study investigated the effect of the air-gap technique over the imaging plate and demonstrated the positional variation of scattered radiation (Persliden Carlsson, 1997). The authors concluded that by using the air-gap technique, the patient irradiation was lowered. Persliden and Carlsson (1997) argued that even field size and patient thickness greatly affected the use of the air-gap. As well as Persliden and Carlsson (1997), Trimble (2000) looked and assessed image quality of lateral thoracic spine radiographs and chest radiographs. These examinations were both done using the grid technique and the air-gap technique. Trimble (2000) found it important to have a large sample of subjects while keeping the specialists evaluating the images small. Trimbles study resulted in the air-gap being better for high image quality than the grid. Similiar to this study, Gouldings study (2006) who looked at image quality in lateral hip radiography when using both grid and air gap technique. The radiographs were obtained from the accident and emergency department Goulding (2006) worked in, where radiographers performed lateral hip shoot through examinations using their preferred air gap or grid technique. Goulding (2006) took a sample from the recorded examinations of both techniques. The researcher excluded examinations with an exposure of 100 mAs or more as well as any duplicate patient numbers due to re-assessment as well as those examinations that used both air gap and grid technique in the same examination as this signified a very large patient. Goulding (2006) compared the sampled gird and air gap radiographs after reporting radiographers evaluated five areas on each radiograph, chosen by the researcher. The radiographers had to score each area from one to five where one is poor and five is optimum. It resulted that the a ir gap technique had improved image quality more than the grid technique. A limitation of this study was, however, that the patients used to test for both techniques were not the same, and so this could have meant that the results were not totally reliable since patient size and exposure factors were not constant but varied depending on each examination. Conclusion The literature reviewed in this chapter has explored furthermore the roles of the air-gap and grid technique in imaging. It has also analysed the effect of scatter radiation and ways to reduce this in order to improve radiographic image quality while limiting the radiation dose to the patient as much as possible. Several studies were reviewed and analysed and will help to improve this experimental research. Some studies that are similar to this study were reviewed and discussed. In the next chapter, a description of the research design used in this study will be presented.

The Battle of King Philip II Augustus of France Essay -- Ancient Hist

King Philip II Augustus of France wasn’t by any means a physically strong individual, but his strengths lay in his grasp of both political and military strategy. He was almost constantly involved in wars from 1180 to 1215. He was fighting his vassals, other kings, both of them together, it didn’t matter; Philip would use political treachery and military tactics to defeat his opponents. When one looks at Philip’s life they notice almost instantly that Philip was constantly fighting someone from the day he became King, to the day he died. Philip was born in Gonesse on August 21st of 1165, his father Louis was determined to have Philip succeed him on the throne; as such Philip was raised with all the training necessary to become a king, he was taught in the ways of politics and war (Smedley 52). All was going to plan until Philip turned thirteen, on a royal hunt; he was separated from his companions and became lost in a forest. He spent hours attempting to find a way out, until he was exhausted by the cold and hunger. Eventually a peasant found him; but this event had caused him to become extremely ill, he contracted a dangerously high fever. His father Louis VII distraught by his son’s illness undertook a pilgrimage to the Shrine of Thomas Becket, in order to pray for his son’s recovery (Smedley 55). He was told that his son had finally recovered, and began his journey back to Paris. On the return journey he suffered a terrible stroke; this began the decline of his health, and eventually leads to hi s death (Smedley 55). Knowing that his health was declining and that he would not be able to lead for much longer, he understood that if he wanted to have Philip succeed him he must act quickly as there were parties at play that w... ...cture, but to anticipate future moves. He deviated from the traditional methods of viewing war as a game of chess, but understood that more elements could be utilized. Through his military history we see wonderful examples of him using rebellions and political means to destabilize military operations of his opponents. He was truly a master of psychological, political, and traditional warfare, and quite possible one of the finest political and military strategists of the Middle Ages. Works Cited The New Encyclopaedia Britannica. Chicago: Encyclopaedia Britannica, 2007. Print. Rees, Simon. "King Richard I of England Versus King Philip II Augustus." Military History Magazine Sept. 2006: 1-5. Print. Smedley, Edward. The History of France, from the Final Partition of the Empire of Charlemagne to the Peace of Cambray. London: Baldwin and Cradock, 1836. Print. The Battle of King Philip II Augustus of France Essay -- Ancient Hist King Philip II Augustus of France wasn’t by any means a physically strong individual, but his strengths lay in his grasp of both political and military strategy. He was almost constantly involved in wars from 1180 to 1215. He was fighting his vassals, other kings, both of them together, it didn’t matter; Philip would use political treachery and military tactics to defeat his opponents. When one looks at Philip’s life they notice almost instantly that Philip was constantly fighting someone from the day he became King, to the day he died. Philip was born in Gonesse on August 21st of 1165, his father Louis was determined to have Philip succeed him on the throne; as such Philip was raised with all the training necessary to become a king, he was taught in the ways of politics and war (Smedley 52). All was going to plan until Philip turned thirteen, on a royal hunt; he was separated from his companions and became lost in a forest. He spent hours attempting to find a way out, until he was exhausted by the cold and hunger. Eventually a peasant found him; but this event had caused him to become extremely ill, he contracted a dangerously high fever. His father Louis VII distraught by his son’s illness undertook a pilgrimage to the Shrine of Thomas Becket, in order to pray for his son’s recovery (Smedley 55). He was told that his son had finally recovered, and began his journey back to Paris. On the return journey he suffered a terrible stroke; this began the decline of his health, and eventually leads to hi s death (Smedley 55). Knowing that his health was declining and that he would not be able to lead for much longer, he understood that if he wanted to have Philip succeed him he must act quickly as there were parties at play that w... ...cture, but to anticipate future moves. He deviated from the traditional methods of viewing war as a game of chess, but understood that more elements could be utilized. Through his military history we see wonderful examples of him using rebellions and political means to destabilize military operations of his opponents. He was truly a master of psychological, political, and traditional warfare, and quite possible one of the finest political and military strategists of the Middle Ages. Works Cited The New Encyclopaedia Britannica. Chicago: Encyclopaedia Britannica, 2007. Print. Rees, Simon. "King Richard I of England Versus King Philip II Augustus." Military History Magazine Sept. 2006: 1-5. Print. Smedley, Edward. The History of France, from the Final Partition of the Empire of Charlemagne to the Peace of Cambray. London: Baldwin and Cradock, 1836. Print.

Discuss the treatment of women in society with reference to Charlotte E

Discuss the treatment of women in society with reference to Charlotte Bronte's Jane Eyre and Margaret Atwood's A Handmaids Tale. In this essay, I will compare a pre-twentieth century novel with a modern novel, and examine the discussion of the treatment of women in society. 'Jane Eyre' was first published in 1847, and was written by Charlotte Bronte. It is the story of a young woman, Jane Eyre, ill treated through childhood, but determined and intelligent. Through the novel, the reader watches her grow and develop as a person, and overcome many problems, to become a respectable, independent woman. It is said that 'Jane Eyre' contains many autobiographical elements from Bronte's own experiences of life. Bronte uses this novel to observe and criticize oppressive social ideas that were common in nineteenth century Victorian society. Jane's position as a governess (another autobiographical element, as Charlotte too was a governess) is an imperative tool in the novel, as it provides a neutral vantage point from which to observe these practices of Victorian society. Governesses were expected to have the education and culture of the aristocracy, but were still looked at as the same status as servants, as they were paid employees. They were seen as lower class, as shown by Lady Ingram in chapter 17: "Don't mention governesses, the word makes me nervous. I have suffered a martyrdom from their incompetence." "In hers [physiognomy] I see all the faults of her class." Female oppression is another prominent issue in the book. Bronte creates struggles that Jane must overcome to achieve equality with men, and she resists the superior attitude of men who believe women should have submissive positions. For ex... ...ppressed. The message is that this balance between men and woman is delicate and its future uncertain. In reading the book you realise that it is entirely possible for woman to lose their rights completely, and the social clock, in relation to woman in society, could be turned back. The Handmaid's Tale is set in the future an any signs of the rights of women as we know them are banished and barren, except in the pain ridden memories of women living reduced roles. Charlotte Bronte, although more subtle in her approach than Atwood, displays just as much passion concerning rights of women. At several points she acknowledges that women's role in society is questionable, and should be a prominent issue in women's minds. I thoroughly enjoyed reading both books and feel that both are excellent pieces of literature that put across a strong, important message.

The Setting of The Cask of Amontillado Essay -- Papers Poe Essays

The Setting of The Cask of Amontillado An important element in any story is setting. Authors use setting to convey certain feelings brought on by the character’s surroundings. It also subliminally serves to illustrate the character’s intentions. In â€Å"The Cask of Amontillado† Edgar Allen Poe uses the dark, imposing setting to do just that, communicate the underlying theme of the story, being death, revenge and deception. Poe begins setting the tone of the story by describing the gloomy and threatening vaults beneath Montressor’s home. The first description of the Montressor home, as well as the reader’s first hint that something is amiss, is the description of the time off Montressor had required his employees to take. This alone lets us know that some of his intentions are less than virtuous. He describes the vaults as extensive, having many rooms, and being insufferably damp. This description of Montressor’s vaults strikes a feeling of uneasiness and fear in the reader, as well as a fear of malevolent things to come. References to the bodies laid to rest in the ca...

A New Definition of Environmentalism

Environmentalism is believed to be a movement, â€Å"especially in politics and consumer affairs† (â€Å"Environmentalism,† 2007).   However, politicians and the media continue to disagree about the connection between anthropo genic greenhouse gas emissions and climate change (Oreskes, 2004).Those that actively work to protect nature against abuse are referred to as environmentalists or people who are part of the â€Å"environmental community† (Shellenberger & Nordhaus, 2005).   The essay about an individual working to protect nature by changing his or her habits and activities is, therefore, a breath of fresh air.   Indeed, it is possible for all individuals to work on protecting nature by changing their habits and activities.While politicians and the media may continue to disagree about the relationship between global warming and anthropogenic greenhouse gas emissions, the individual who deeply contemplates the consequences of his or her habits and activi ties is wiser for sure.He or she does not need to join the so-called â€Å"environmental community† (Shellenberger & Nordhaus).   Neither does it matter that others may disagree with him or her.   Rather, it is the here and now that the individual protector of the environment is concerned with.The essay about the individual protector of the environment thereby calls for a new definition of environmentalism: it is a movement, especially in politics, consumer affairs and individual activities, â€Å"that works towards protecting the natural world from harmful human activities† (â€Å"Environmentalism†).Whereas politics and consumer affairs are concerned with the protection of the environment on behalf of the unaware if not ‘uncertain’ masses, it is the individual protector of the environment that refuses to accept defeat in this regard.   He or she does not doubt that his or her activities impact the environment.   As a matter of fact, his or her right-mindedness in this matter should be seen as the motive force behind environmental politics and consumer affairs.ReferencesEnvironmentalism. (2007). NineMSN Encarta. Retrieved March 30, 2008, from http://au.encarta.msn.com/encnet/features/dictionary /DictionaryResults.aspx?refid=18616Oreskes, N. (2004). Beyond The Ivory Tower: The Scientific Consensus on Climate Change.Science 306 (5702): 1686. Retrieved March 30, 2008, from http://www.sciencemag.org/cgi/content/full/306/5702/1686.Shellenberger, M., & Nordhaus, T. (2005). The Death of Environmentalism: Global WarmingPolitics in a Post-environmental World. Retrieved March 30, 2008, from http://www.grist.org/news/maindish/2005/01/13/doe-reprint/.