A Hydraulic Accumulator Energy Engineering Essay

A Hydraulic Accumulator Energy Engineering Essay A hydraulic accumulator is a device in which potential energy is stored in the form of a compressed gas or spring, or by a raised weight to be used to exert a force against a relatively incompressible fluid. They are used in fluid power systems to accumulate energy and to smooth out pulsations. Accumulators store energy when hydraulic system pressure is greater than the accumulator pressure and provide hydraulic energy when the accumulator pressure is greater than the system pressure. By storing and providing hydraulic energy, accumulators can be used as a primary power source. Accumulators are inherently dynamic devices, they function when configuration changes (actuators moving, valves opening, etc.) are occurring within a hydraulic system. Accumulators respond very fast to configuration changes, nearly instantaneously for gas accumulators. They are usually used in conjunction with a pump/motor in a hydraulic circuit. A hydraulic system utilizing an accumulator can use a smaller fl uid pump since the accumulator stores energy from the pump during low demand periods. The pump doesnt need to be so large to cope with extremes of demand, so that the supply circuit can respond more quickly to any temporary demand and to smooth pulsations. The capability and affect of the accumulator is determined by the overall volume of the accumulator and preload/pre-charge of the spring/gas. There are 4 types of accumulators: bladder, diaphragm bladder, piston (either spring or gas controlled) and metal bellows. The choice of accumulator to use in a given application depends on required speed of accumulator response, weight, reliability and cost. Pressurized gas accumulators will have the faster dynamic response and are reliable. Metal bellows accumulators are very reliable, but will not respond as fast as a pressurized gas accumulator. Accumulators with seals generally have the lowest reliability. Accumulators are either spherical or cylindrical in design. Bag, piston and metal bellows accumulators are cylindrical. Diaphragm accumulators may be spherical or cylindrical. Accumulators are usually manufactured into 2 halves which are either welded or threaded together. A fill port is installed at one end of a gas accumulator and the hydraulic connection fitting (with poppet valve, if required) is installed at the opposite end. For a spring accumulator, the non pressure sid e usually has a fitting that connects to the hydraulic reservoir (for seal leakage and to alleviate back pressure on a piston). Materials are usually steel, but accumulators may also be made from aluminium or a composite (filament wound) material. Compressed gas accumulators are by far the most common type; these gas accumulators take advantage of the fact that the gas is compressible. A gas accumulator has a gas pre-charge that is less than the nominal hydraulic system pressure. As hydraulic fluid enters the accumulator the gas is compressed to the nominal system pressure, which is an equilibrium position and represents the maximum amount of energy stored by the accumulator. As system hydraulic pressure drops, the gas will expand pushing hydraulic fluid back into the system. The gas pre-charge level is an important parameter for gas accumulators since the pre-charge and overall accumulator volume; determine the maximum amount of hydraulic energy that will be available to the system. The pre-charge is the pressure of the gas in the accumulator without hydraulic fluid in the fluid side. A gas accumulator is pre-charged with nitrogen gas when there is no hydraulic fluid in the accumulator to the desired pressure. The gas accumulator pre-charge is a very important variable for ensuring optimal accumulator performance and maintaining long life of the accumulator. Too high of a pre-charge pressure and the fluid volume capacity is reduced. Furthermore, if a bag accumulator charge is too high than the bag may hit the poppet valve which could damage the bag through repeated hits in service, or cause a fatigue failure in the poppet valve assembly. For a piston accumulator, the piston may be driven into the stops repeatedly affecting seals or cause a fatigue failure in the piston stop. Too low of a pre-charge pressure and the accumulator may not maintain desired minimum hydraulic system pressure. Also a low pre-charge pressure will allow a piston accumulator to repeatedly hit the up stops leading to premature failure of the accumulator. For a bag accumulator, the bag may be forced into an unnatural shape (e.g.,with folds) leading to bag damage and premature bag failure. When sizing an accumulator the pre-charge pressure is an input to the sizing process. However, once the accumulator is sized the minimum and maximum gas volumes should be computed (under worst case conditions) and analyzed to ensure piston stops are not hit or that a bag cannot fully collapse or expand completely in the accumulator. Bladder Accumulator A bladder accumulator consists of pressure vessel with an internal elastomeric bladder with pressurized nitrogen on one side and hydraulic fluid on the other side (system side). Figure 1 shows a bladder accumulator. It has 3 stages of operation: The accumulator is charged with nitrogen through a valve installed in the top. The accumulator will be pre-charged to nominal pressure when the pumps are not operating. Secondly when nominal hydraulic system pressure is applied the bag will be compressed to its fully compressed state. When the bag is fully compressed, the nitrogen pressure and the hydraulic pressure are equal. Finally as system pressure drops the bag expands, forcing fluid from the accumulator into the system. As the bag expands pressure in the bag decreases. The bag will continue to expand until the bag pressure equals the hydraulic pressure (which will be lower than nominal system pressure) or the bag fills the entire accumulator volume which is an undesirable situation. A poppet valve keeps the bag in accumulator from being pulled into the downstream tubing should the bag over-expand. If the bag was pulled into the downstream tubing, the accumulator would never recharge and normal flow from the pump would be constricted. The maximum flow rate of the accumulator is controlled by the opening area (orifice) and the pressure difference across the opening. Figure http://www.globalspec.com/NpaPics/18/146314_030520074661_ExhibitPic.JPGAccumulator, Bladder Typehttp://www.globalspec.com/NpaPics/18/146314_030520074661_ExhibitPic.JPG The main advantages of a bladder accumulator are fast acting, no hysteresis, not susceptible to contamination and consistent behaviour under similar conditions. Accumulators are easy to charge with the right equipment. Because there is no piston mass, the speed of the bladder accumulator is governed by the gas, which reacts very fast to changes in hydraulic system pressure. Hence bladder accumulators are the best choice for pressure pulsation damping. Also, the bladder attachment internal to the accumulator has proven to be very reliable in service. Of course there is always the potential for bladder failure, which is a failure that would not usually be detectable in service. Also, temperature differences on the gas will have some affect on performance. The main limitation of bladder accumulators is the compression ratio (maximum system pressure to pre-charge pressure) which is limited to approximately 4 to 1. Hence gas accumulators will be larger than other accumulators for the same flow requirements. The pre-charge pressure is typically set to approximately 80% of the minimum desired hydraulic system pressure. Diaphragm Accumulator A diaphragm accumulator is similar to bag accumulator except an elastomeric diaphragm is used in lieu of a bag. This would typically reduce the usable volume of the accumulator so the diaphragm accumulator may not have volume capacity of a bladder accumulator. A schematic of a diaphragm accumulator is shown in Figure 2. http://www.machinerylubrication.com/articles/200907/pg26b.gif Figure http://www.machinerylubrication.com/articles/200907/pg26b.gif The behaviour characteristics of a diaphragm accumulator are similar to a bag accumulator and have the same advantages and disadvantages. However a diaphragm accumulator may be spherical or cylindrical (or possibly other shapes) which may be an advantage in some installations. The main difference with bladder accumulators is an increased maximum compressions ratio (maximum system pressure to pre-charge pressure) of approximately 8 to 1. Piston Accumulator A gas piston accumulator is shown in Figure 3. A gas piston accumulator has a piston which slides against the accumulator housing on seals. On one side of the piston is nitrogen and on the other side is the hydraulic fluid and connection to the system. A fill port allows pressurization of the nitrogen. Accumulator, Piston Type Figure http://www.tobul.com/index.php?option=com_contenttask=viewid=13Itemid=27 A gas piston accumulator will not respond to transient pressures as fast as a bladder accumulator due to the mass of the piston (frequency characteristics depend on piston mass and spring characteristics of the nitrogen). However, a piston accumulator will have better damping due to hydraulic leakage (viscous damping) and friction between the piston and housing (coulomb friction seal friction). Piston accumulators may also be more prone to leakage than other types of accumulators due to the seals. Piston accumulators will generally provide higher flow rates than gas accumulators for equal accumulator volumes. This is because piston accumulators can accommodate higher pressure ratios (maximum system pressure to pre-charge pressure) than gas accumulators, up to 10 to 1, compared with bladder accumulator ratios of 4 to 1. The disadvantages of piston accumulators are that they are more susceptible to fluid contamination, have a lower response time than bladder (unless the piston accumulator is at a very high pressure) and will have hysteresis from the seal friction. The pre-charge for a gas piston accumulator is typically set to around 90% of minimum desired hydraulic system pressure. A schematic of a spring piston accumulator is shown in Figure Accumulator, Spring Type In a spring accumulator, the spring applies a force to a piston which compresses (or pressurizes) the fluid in the accumulator. As normal system pressure, the spring will be fully compressed. As system flow demands exceed the pump capacity, the spring will extend pushing the piston which in turn pushes fluid into the adjoining pipe. Hence the accumulator supplements pump flow. The maximum response time of the accumulator is set by the natural frequency, which is computed using Metal bellows accumulators are used where a fast response time is not critical yet reliability is important. Emergency brake accumulators are a good application for metal bellows accumulators. The metal bellows accumulator consists of a pressure vessel with a metal bellows assembly separating fluid and nitrogen. The accumulator is similar to a piston accumulator, except a metal bellows replaces piston and piston seals. Metal bellows accumulators are very reliable and long life components, and have a proven service history. Metal bellows accumulators are pre-charged by supplier and then permanently sealed leading to a maintenance free accumulator. Metal bellows accumulators will be slow in responding to pressure changes due to increased mass of piston and bellows. The advantages to the metal bellows type include exceptionally low spring rate, allowing the gas charge to do all the work with little change in pressure from full to empty, and a long stroke relative to solid (empty) height, which gives maximum storage volume for a given container size. The welded metal bellows accumulator provides an exceptionally high level of accumulator performance, and can be produced with a broad spectrum of alloys resulting in a broad range of fluid compatibility. Another advantage to this type is that it does not face issues with high pressure operation, thus allowing more energy storage capacity. Applications of Accumulators to KERS One of the main applications of hydraulic accumulators is storing energy. Hydro-pneumatic accumulators incorporate a gas in conjunction with a hydraulic fluid. The fluid has little dynamic power storage qualities. The fluid can only be reduced a small amount in volume even under high pressure. Therefore when only a small amount of the total contained volume is released, the pressure of the remaining fluid in the system will drop to zero. However, the relative incompressibility of a hydraulic fluid makes it ideal for fluid power systems and provides quick response to power demand. The gas, however working with the hydraulic fluid in the accumulator, can be compressed to high pressures and low volumes. Potential energy is stored in this compressed gas to be released upon demand. In the piston type accumulator the energy in the compressed gas exerts pressure against the piston separating the gas and hydraulic fluid. The piston in turn forces the fluid from the cylinder into the system a nd to the location where useful work will be accomplished. On this basis, with respect to all the types of accumulator a hydro-pneumatic accumulator would be ideal for storing the energy taken out of a bike whilst braking.. Of course the loss of pressurized gas in a sealed accumulator is a failure critical to safety when it plays such an important role as braking. A team of engineering students from university of Michigan undertook a project to use a hydro-pneumatic regenerative braking on a bicycle. It was a redevelopment of a heavier previous attempt to make a working prototype to fit within a 29 front wheel. They use a 0.5L accumulator and believed this to be sufficient in storing the required energy at a maximum working system pressure of 5000psi. They failed to test and thus supply conclusive results for the performance characteristics but through theoretical analysis they prescribe the key parameters fig. Figure Its weight is clearly impractical as it weighs almost as much as a conventional bike at 13kg. In terms of weight of a bicycle with respect to saving weight, it is more important to have lighter wheels than a lighter bike frame. This is because the rolling resistance is applied at the wheels although it carries half the overall weight of bike and rider a lighter wheel makes it easier to initially start a bike. Based on the team from michigans ( ) the following calculations outline the practicality of implementing a hydraulic KERS. Firstly for a hydraulic system to be implemented the storage must be addressed the capacity must be determined and pressures needed to store the kinetic energy. A bike braking from 20mph requires 5000J of energy to power. From Parkers website a manufacture of accumulator and motors parkers rate the ACP series accumulators at max pressure 5000psi, if assuming A hydraulic KERS must use a hydraulic motor to provide enough torque to drive the bike as well as provide enough resistive torque to be an effective brake. A bicycle travelling at 20mph on 26 wheels spins the motor through 18:1 gear ratio of the pump gear train which then spins the motor 4632rpm, corresponding to 4.52 N-m torques at 3000 psi. This translates to a braking torque of about 81.36 N-m applied to the main gear due to the 18:1 gear ratio. From this brake torque is an effective brake On release of pressure fully charged 5000 psi accumulator generates 7.57 N-m of torques. The 14:1 gear ratio of the motor gear train applies a 105 N-m torque to the main bicycle cluster gear. 7.57 N-m corresponds to around 800 rpm from its torque rpm curve, which turns the main gear at around 57 rpm due to the 14:1 gear ratio. This torque from fig can propel a bike at Conclusion The accumulator doesnt need to be an excessively large capacity to release enough energy to propel a bike 20mph, upon releasing the energy at a pre-charge of 3200psi. But a larger accumulator is needed for the accumulator to give more than one bursts using its full capacity. A hydraulic motor can produce 81.36N-m braking torque which is an effective brake. Furthermore an accumulator can power a hydraulic motor provide an accelerating torque to propel a bicycle. However based on the weight of the design from univerty of Michigan their prototype was 13kg, they used two accumulators plus they attached it to a bracket that probably contributed to the majority of the weight.

Defining the Life of Robert Louis Stevenson The Strange Case of Dr. Jekyll and Mr. Hyde :: Dr. Jekyll and Mr. Hyde Essays

Defining the Life of Dr. Jekyll and Mr. Hyde      The focal point of this essay is to define the life of Dr. Henry Jekyll, and the transformation he went through in becoming Edward Hyde. Dr. Henry Jekyll is a physician in London.   He is very well respected and is currently experimenting the dual nature of mankind. Edward Hyde is a manifestation of Dr. Jekyll's personality. He is accused of committing evil acts throughout the novel.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The first scene consists of Mr. Richard Enfield's and Mr. Utterson walking along a street in London.   Mr. Enfield has a recollection of a previous incident in which he witnessed an extremely unpleasant man trampling upon a small screaming girl while this man was running somewhere. A large crowd had gathered around and they saw the man, Edward Hyde. The crowd forced the man to give money to this girl for trampling over her. Hyde did not run over her for any reason. He just did it out of spite and evil. He represents all the evil in the world. The reaction of others to him is one of horror because while looking at him, others feel a desire to strike out at him and kill him. His physical appearance brings out the worst evil in other people. Since Hyde represents evil, he is symbolically represented as being much smaller than Dr. Jekyll.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   I believe Dr. Jekyll created Hyde because he had a theory that man has a good side and a bad side. While investigating this, he developed a potion that could release the evil in a person in the form of a totally different person. Then this person could commit any evil act it wanted, and then drink the potion to return back to normal. The only problem with this is the fact that he drank this potion so many times that he was no longer able to control this process. He was unable to transform back into Dr. Jekyll.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Another example of Hyde's evil is in the killing of Sir Danvers Carew. Sir Danvers appears to have been killed for no apparent reason. The murder of Sir Danvers was seen by a maid who was working nearby. She states that Hyde meet with a man in the street. After the two exchanged words, Mr. Hyde lifted his heavy walking stick and clubbed the old man to death.

Actor and Ubermarrionette

The Actor and the Uber-Marionette Edward Gordan Craig did not think of acting as an art-form; he considers it incorrect to speak as though actors are artists. He started out as an actor, but became more interested in art and he ended his acting career for theatrical design. He asserted that the director was the true artist of the theatre and viewed actors of little importance and even declared that they were very replaceable. Throughout his career in theatre production, he was viewed as extremely difficult to work with and he refused to produce anything that he did not have complete artistic control over.His ideals about the theatre and how it should be run were written in his most famous and rather controversial essay, â€Å"The Actor and the Uber-Marionette. † In this article, he seems to suggest that the stage has no place for actors and they should be banished and be replaced by super-marionettes. His analysis of the human actor compared to that of the marionette seems to be inferior. He believed that art can only come by creation; he believed what actors were doing was imitation. He believed that true artists capture the spirit of things and the actor was only mere pretending to capture the true essence of art.It is obvious in his language that Gordan Craig was very passionate of the theatre and he saw the commercialization of the stage as the destruction of theatre. He seems to think to think that actors were the root cause of the degradation of the art of the theatre , but he seem to have an underlying intention to urge actors to reform their acting and create for themselves a new form of acting. Gordan Craig believed that â€Å"Art arrives only by design. † (Craig, p. 55) This means that acting was not considered art by this definition because he saw actors as only being able to imitate and impersonate.He believed that the only way to make art was through creation and â€Å"Therefore in order to make any work of art it is clear we may onl y work in those materials with which we can calculate. Man is not one of these materials. † (Craig, p. 55) He believed that art can only be created by â€Å"materials† and those actors using their own bodies as materials for their art-form were considered an â€Å"accidental nature. † He claimed that the actor was controlled by his emotions and therefore unreliable and untrustworthy, â€Å"But with the actor, emotion possesses him; it seizes upon his limbs, moving them wither it ill. † (Craig, p. 56) He saw the human body, which the actors use as their material, as easily manipulated by emotions. Human emotion is so strong that it dictates every aspect of the actor such as his facial expressions and the sounds of his voice. He argued that the human emotion could work against the actor at any given moment and betray him. Gordan Craig liked having control of every aspect of the production and he did not like the idea of not having complete control of the act or’s voice and movements.He likely believed that with marionette, he would have a way to control the unpredictability of the actor and express a wide range of emotions. This is similar to how Jim Henson could express a distinguishable range of emotions using only the eyes of the Muppet. The placement of the eyes for a Muppet was the key to success for the character. In The Muppet Movie (1979), Miss Piggy is able to convey anger and even aggression through the puppeteer’s use of her eyes. This can be seen during the scene where Miss Piggy fights off Doc Hopper and his henchmen in the barn.Another example would be when Miss Piggy first gazes eyes on Kermit the Frog at the fair; her infatuation with Kermit is made obvious through usage of her eyes. Jim Henson also frequently says that Kermit the Frog was much bolder than himself and â€Å"He can say things I hold back. † (Seligmann, J. ; Leonard, E. (May 28, 1990). â€Å"Jim Henson: 1936–1990†. Newswe ek. ) In â€Å"The Actor and the Uber-Marionette,† Gordan Carig seemingly wants to do away with actor and have him replace by the uber-marionette.He says that even if the actor were to have original ideas of his own, â€Å"his nature would still be in servitude; his body would have to become the slave of his mind. † (Craig, p. 61) He goes on to say that the body of man is â€Å"utterly useless as a material for an art. † (Craig, p. 61) The only way actors can escape from this predicament is to reform their way of acting, â€Å"Today they impersonate and interpret; to-morrow they must represent and interpret; and the third day they must create. †(Craig, p. 61) This is the only solution to bringing back the essence of the theatre.The actors must learn to create and only then they can have freedom of creation and having something you can call your own. Gordan Craig thinks that actors are only able to imitate art, but cannot recreate it. He thinks of them as fakes who only do impersonations and never offering any contribution to the art. The actors masquerade as artists and they rarely think about creating art. They are copies and are incapable of â€Å"capturing the spirit and essence of idea to an audience. † (Craig, p. 63) Gordan Carig wants the actors to redeem themselves and help revive what is failing in the theatre.This importance of creation is predominant in Muppets and Sesame Street characters. Each Muppet has their own individual identity and their own unique aspects that define them. The puppeteer has freedom over the control of the Muppet and can decide to portray the Muppet in whatever way is desired. This is where Gordan Craig’s ideals differ with Muppets because some Muppets are based upon real people. That is not to say they are exact imitations, but they certain qualities resemble their real counterparts. Although they are their own characters, some Muppets do have a level of impersonation.For example, An imal is said to be based on Keith Moon, the drummer for The Who. Caroll Spinney who performs Oscar the Grouch on Sesame Street said he based Oscar’s cranky voice on a New York cab driver that he once had the pleasure of riding with. The marionette has evolved from its predecessors; Gordan Craig has even said that it is â€Å"a rather degenerate form of a god. † (Craig, p. 82) Clearly, he holds the marionettes of higher value than the actor. He wants people to acknowledge how special the marionettes are and he is disappointed that puppets are regarded â€Å"low comedians. (Craig, p. 82) To him, the marionettes are â€Å"the last echo of some noble and beautiful art which has passed civilization. † (Craig, p. 82) He hates how modern puppets are being used and he feels they are being utilized incorrectly. He longs for the day in which puppets are used again as medium for the intelligent thoughts of the artist. The ideal situation was by creating the uber-marionett e; we can rid the theatre of the weakness that is the actor who is under the influence of his emotions.He saw the uber-marionette medium as perfect, pure and completely able to express the artist’s intentions because the marionette would be made in the artist’s image. Craig Gordan’s vision was similar to the situation in which Jim Henson was in where he was afraid that his company would be type casted as purely children’s entertainment. He wanted to break out in to the adult audience. American networks initially rejected his idea because they thought that Muppets only appealed to children and that adults would not be interested. Eventually he was able to get â€Å"The Muppet Show† financing through a British network.He was able to prove that the Muppets appealed to a variety of audiences, both young and old. It was no doubt that Muppets appealed very easily to children and this theory is very evident in Sesame Street. The usage of Muppets helped pr opagate the idea that â€Å"Sesame Street was built around a single, breakthrough insight: that if you can hold the attention of children, you can educate them†. (Gladwell, The Tipping Point: How Little Things Can Make a Big Difference p. 100) Muppets were good teaching tools because children can easily recognize them and they capture their attention.Edward Gordan Craig’s intentions through â€Å"The Actor and the Uber-Marionette† were to influence a revival of theatre art. He wanted actors to reform their way of acting and reacted strongly against the actor’s dominance in theatre. The creation of something by the artist was closer to true art and actors were merely imitating this. Actors were impersonators and were not intellectual and could not capture the spirit or essence of the art. The actor’s own emotions and personal beauty ruined the director’s vision. He truly believed that theatre should banish the actor and be replaced by the ube r-marionette.The marionette was much more reliable and trustworthy and the director could have full control over it. The puppet had a long history and was linked to many past great works of art. In his closing statements he tells us his desire, â€Å"I pray earnestly for the return of the image—the Uber-marionette to the Theatre; and when he comes again . . . , he will be loved so well that once more it will be possible for people to return to their ancient joy in ceremonies—once more will Creation be celebrated—homage rendered to existence and divine and happy intercession made to death. † (Craig, p. 94)

Dystopia Essay 1984 and Harrison Bergeron - 1818 Words

Year 11, English Extension Essay ( 2 CORE texts and 1 RELATED text) What ideas do you see linking the texts you have studied through your exploration of Utopias and Dystopias. The novels Utopia by Thomas More and 1984 by George Orwell and short story Harrison Bergeron by Kurt Vonnegut explore the Utopic and Dystopic genre through the structure and regulations of their societies. In Utopia, More provides us with a contemporary understanding of society and human nature, with an indepth study of morals, values and beliefs in England around the Renaissance Era. 1984 was published while the Second World War was fresh in people’s minds, creating fears amongst society with Orwell emphasizing the possibility of such a dehumanised and controlled†¦show more content†¦In Utopi, from Book 1, More explains how the hierarchy system is dominated by the King in his time. By reffering to the king as â€Å"His invincible Majesty†, we can see the importance and and how much power the king had. Through Raphael, More explains the abuse of power by Kings and how by â€Å"hook or by crook† they attempt to acquire new kingdoms rather than govern the existing ones properly. More highlights the king’s ambitions in gaining power, money and expansion of kingdoms showing their negligence of their actual duties. Raphael uses an example the King of France aims to seize milan while also maintaining his authority over his current kingdom. This example demonstrates how powerful the kings are and also their greed in trying to get more than they already have. We see that their focus is not on their people, but on gaining assets and acquiring new kingdoms. In Book One, More uses am accumulation of examples and anecdotes to emphasize the nature of authority in 16th century Europe. This European style governance is later juxtaposed with the style of Government in Utopia in Book 2. This highlights how the King of France is so nelgecting of his people, unlike the Utopian rulers. â€Å"Why do you suppose they made you a king in the first place,? Not for your benefit, but for theirs.† More through the persona of Raphael, warns against the power-hungry and ambitiousShow MoreRelatedA Dystopia Is Not A Contemporary Idea2159 Words   |  9 PagesA dystopia is an unpleasant and repressive society whic h usually has the intent to make equality an opportunity for all. 1984 and â€Å"Harrison Bergeron† are two examples of dystopia literature. In each, technological advances and psychological stimuli is designed to overwhelm an individuals thought. Based upon these pieces of literature, is it possible for a utopia exist? For clarification purposes, there are some definitions to keep in mind when reading this essay. The dictionary defines a utopiaRead MoreEssay Grade Justification967 Words   |  4 Pagesoverall earned a B+ as a final grade. During the semester my grades have been consistently average and my essays have gotten progressively more detailed and although they haven’t been the most concise they have gotten a lot stronger and showed more promise as the semester progressed which is showing that, during the time I have been learning things in class and applying those skills towards essays, and homework. During the class period I have also participated in almost, if not all of the class discussionsRead MoreFahrenheit 451 Critical Essay1607 Words   |  7 Pagesï » ¿Lintang Syuhada 13150024 Book Report 1 Fahrenheit 451 Critical Essay Human beings are naturally curious. We are always in search of better ideas, and new solutions to problems. One of a basic idea of Indonesia has been freedom of thinking and a free flow of ideas. But in some societies, governments try to keep their people ignorant. Usually, this is so governments can keep people under control and hold on to their power. In trying to keep people from the realities of the world, these oppressive