COM 263 assignment # 3 Essay Example | Topics and Well Written Essays - 500 words

COM 263 assignment # 3 - Essay Example By understanding this, she could choose her words to convey the intellectual meaning without the cultural identity becoming an obstacle. This would extend to her non-verbal communications such as attire, stance, and demeanor. Cross culture communications requires that we look at ourselves and reach beyond our limitations in an effort to fit ourselves into the situational context and become more universal (Fitzgerald, 197). Understanding our own cultural identities is the building block that intellectual communication is based on. Being a woman and returning to school as an older student has influenced my ability to communicate effectively between cultures. As a woman, I must be aware that my communication may become genderized. When speaking to a male or mixed audience, it is imperative that I understand the communication methods I have acquired as a female as well as the perception of the audience. If I am speaking to a diverse audience that has various ethnic groups or races, it is important that I understand how my identity is viewed by their culture. If I were speaking about the right of a woman to equal pay for equal work, my vocabulary and presentation would vary depending on if I am speaking to a black woman or a Muslim man. As an older student, I can be caught mistakenly thinking that I know more than lifes experience has actually given me. My skills at presenting a case for a viewpoint may be lacking even though I have an emotional understanding of the argument. My identity as older does not directl y coincide with that of being a better student. When communicating with other students, age may garner respect or the opposite may occur. Only by understanding my own identity can I find ways to communicate more clearly and effectively deal with this obstacle. In the situation of working in another department temporarily, there are several identities that are brought to the situation. An important identity is that all the people work for the same company.

Born Global Firms Essay Example | Topics and Well Written Essays - 2500 words

Born Global Firms - Essay Example These firms are established to go global from the first day with a general view that the world is a single market and not an extension of the domestic market. Currently, there is a rapid increase in these firms, most of which have their origin from developed economies. Most of these firms are technological in nature and take advantage of the high technology developments in these countries. However, the firms are not limited to technology but are distributed across other areas as well. This report seeks to understand born global firms to details regarding their formation and the mode of operation. Born Global Firms Introduction Born global firms are business entities that are formed with the single purpose of doing business internationally. From its formation, a born global firm has the main objective of attaining a competitive advantage from harnessing resources and selling its products in many countries, and in most cases, these firms go global within their three years of inception. Multinationals are usually referred to as global firms, though there are major differences between multinationals and born global firms. ... Therefore, the main differentiating factor in these firms is that they have a borderless worldview and all their strategies are geared towards achieving a global presence. In this report, born global firms will be investigated in detail to understand the reasons behind the rapid increase in such firms in the recent past, how the companies undertake their operations, their features and the challenges that these firms face in their operations. The aim of this paper is to derive a better understanding of born global firms, the mode of operations in the global market and their differences from the conventional multinational organizations. Background study Michael Rennie coined the born global tag name in 1993 after studying a new concept of new firms that were established with the single purpose of competing on a global scale to harness resources in a number of countries at the same time (Jones et al., 2011). The interesting aspect of these firms is in the way a small firm is established with the single intention of meeting the varying needs of customers on a global scale. Such an approach requires a new focus in understanding the concept behind internationalization of firms and the need to attain a global status today. The new concept of a born global is to satisfy the need of customers on a global scale from its first day of inception, in that the firms are internationalized by design and not by emergence (Jones et al, 2011). In international trade models, a firm wishing to go global has to outlay the initial investment and make the entry costs before it commences operating globally.  

Power Blackout Preventing By Power Swing Detection

Power Blackout Preventing By Power Swing Detection Power Blackout Preventing By Power Swing Detection  and Out-Of-Step Protection   Power system disturbance, such as fault occurrence, automatic reclosing, and large loads disconnection. These conditions force the generating units to adapt with the new load condition but the generators cant do this instantaneous due to the inertia. This cause a power swing. It may be stable power swing or un stable power swing. In the stable power swing the generator can return to the new equilibrium state. On the other hand, in the un stable power swing the generator cant reach to the steady state operation and run out of step and may lead to the blackout. in the case of power swing the load impedance may enter into the operation characteristic of the distance relay and case unwanted tripping for the transmission lines. So, the distance relay isnt supposed to tripe under the power swing if stable or unstable to give the system the availability to return to its steady state. A power swing block PSB its a function inside the modern distance relays that prevent unwanted tripping by block the tripping signal in case of stable or unstable power swing. However, when the fault happens due to a Power swing it must be cleared very rapidly with high level of dependability and selectivity. Out-of-step trip (OST) in is a function that included in the modern relays to achieve the separation of the power system under the unstable power swing. The major aim of this function to differentiate between the stable and unstable power swing and separate the power system into predetermined zones to achieve the stability and continuity of the service. Key words:  Power Swing Detection; Out of Step Protection; Distance Protection. USA United states of America NERC North American Electric Reliability Corporation N-1criterion Most security rules therefore call for the system to be able to withstand the loss of any single component UCTE Union for the Coordination of the Transmission of Electricity PSB Power Swing Block OOS Out-of- Step OST Out-of-Step Trip TOSB Setting Time of out-of-step Blocking TOST Setting Time of out-of-step Tripping Figure 1 Causes due to different disturbances Figure 2 Two-Machine System model Figure 3 The Power Angle Curve Figure 4 The Equal-Area Criterion (Figure shows a fast fault clearance and a stable swing) Figure 5 Unstable System due to Slow Clearing Time Figure 6 Wrong operation of distance relay due to Power Swing Figure 7 Two-Blinder Power Swing Detection Scheme Figure 8 Automatically sized power swing area. Figure 9 Monotony criterion. Figure 10 Continuity criterion Figure 11 Smoothness criterion. Figure 12 Logic for power swing detection Figure 13 Impedance trajectory for 3-machine power swing Figure 14 Impedance trajectory during stable power swing. Figure 15 Internal fault B-G during a power swing. Figure 16 Internal fault B-G with single pole trip during a power swing. Figure 17 External fault in BC-G during a power swing. Figure 18 Example of a reverse busbar fault during power swing. Figure 19 Rotor angle and impedance trajectories for stable power swing. Figure 20 Rotor angle and impedance trajectories for unstable power swing. Figure 21 Basic signals for out of step detection. Figure 22 Logic for special out of step tripping. In the previous few years we have suffered from big disturbances in the power system which caused complete blackout and millions of users including the industry have suffered from big economical losses. These disturbances cause big fluctuations in active and reactive power, low voltage, voltage instability and angular instability between the generated power and consumed power which results in loss of generation and load which effected on both sides the power generation and the end customers. During the steady state operating condition, the power systems operates on the nominal frequency (50Hz or 60Hz) +/- 0.02 Hz and Voltage=Nominal voltage +/- 5% [1]. The complete synchronism of nominal frequency and voltage at the sending and receiving ends make complete balance of active and reactive power between generated and consumed active and reactive powers. Power system faults, line switching, generator disconnection, and the loss of large blocks of load result in sudden changes to electrical power, which is due to the causes shown in Fig 1. Disturbances Line Switching Generator Disconnecting Paralleling other Generator Addition of load Loss of load Causes Loss of Synchronism Between Voltages Loss of Synchronism Between phase sequence Loss of Synchronism Between phase angles Loss of Synchronism Between frequencies 1.1. Blackout History 1.1.1 Some blackouts became in 2003 (during six weeks). in the northeastern USA and central Canada and in Europe, which affected more than 100 million people. On 14 August the northeastern USA and central Canada: †¢ 62 GW power outage, affected 50 million people. †¢ power supply restoring took some days. On 14 August London †¢ 724 MW power outage, affected 410 thousand people. †¢ power supply restoring took 40 minutes. On 2 September the southern Malaysia †¢ affected 5 states (out of 13) in Malaysia, including the capital Kuala Lumpur. †¢ power supply restoring took 5 hours. On 5 September Birmingham †¢ 250 MW power outage, affected 220 thousand people. †¢ power supply restoring took 11 minutes. On 19 September nine US states and parts of Ontario, Canada †¢ affected 4.3 million people. †¢ cause hurricane Isabel. On 23 September Denmark and Sweden †¢ affected 5 million people. †¢ power supply restoring took 4 hours. On 28 September Italy †¢ affected 57 million people. †¢ power supply restoring took 4 hours. [1], [2], [3] Blackout in the Northeastern USA and Central Canada 14 August 2003 Initially the event was the tripping of the power line that caused by the short circuit to ground due to tree contacts. Blackout in the northeastern USA and central Canada was studied by The North American Electric Reliability Corporation (NERC) and some contravention of safety and reliability standards was identified: †¢ following the outage of the first 345-kV line, dispatcher of the power system did not make the necessary actions to return the system to a safe operating state within 30 minutes to fulfillment of N-1criterion which mean Most security rules therefore call for the system to be able to withstand the loss of any single component. When a power system satisfies this criterion, it is said to be N-1 secure †¢ dispatchers of neighboring transmission system were not informed about this situation. †¢ insufficient training of dispatchers. †¢ functionless monitor system in part of the power system. Reliable and safety operation of the power system The North American Electric Reliability Council (NERC) have developed the operating of the system and planning standards to confirm the reliability and the stability of a transmission network that are depend on seven key concepts: Balance power generation and demand continuously. Balance the reactive power supply and the demand to keep scheduled voltages. Monitor the power flow over the transmission lines and other facilities to ensure that thermal (heating) limits are not exceeded. Keep the system in a stable condition. Operate the system so that it remains in a reliable condition even if a contingency occurs, such as the loss of a key generator or transmission facility (the N-1criterion). Plan, design, and maintain the system to operate reliably. Prepare for emergencies Blackout in Italy on September 28, 2003 The situation in the Italian power system before blackout wasnt exception. †¢ total load of Italy was 27 444 MW. †¢ 3 487 MW pump load. †¢ 6 951 MW physical import to the Italian power system. †¢ some transmission lines in neighboring power systems were out of service by reason of scheduled maintenance. †¢ the Italian power system was connected to neighboring power systems via 15 transmission lines. Sequence of events of the blackout in Italy The initial event was the 380 kV line tripping in Switzerland. Fewer than 25 minutes after this event the Italian power system ceased to operate synchronized to the UCTE system. Union for the Coordination of the Transmission of Electricity 03:01:42 the 380-kV line tripping in Switzerland (Lavorno Metlen) line was heavy loaded at 86%. †¢ The cause of tripping a wire contacted to a tree. †¢ The attempts of single-phase auto-reclosing and also the attempt of the operators to put this line back into operation were not successful and the line was disconnected by its protection device, due to high phase angle (42 °). †¢ After the Lavorno Metlen line tripping, the other 380 kV line in Switzerland (Sils Soaza) became overloaded. 03:11 the Swiss dispatch asked the Italian dispatch to reduce the import of Italy by 300 MW (on scheduled value). 03:25:21 the second overloaded 380 kV line tripping in Switzerland (Sils Soaza). 03:25:25 the third overloaded 380 kV line tripping in Switzerland. 03:25:26 the interconnection line Austria Italy (Lienz Soverenze) tripping. 03:25:33 the Italian power system started to disconnect from the UCTE system After disconnection Italy from the UCTE system the frequency in the Italian power system dropped suddenly, caused by the negative imbalance between power injection to the system and system load. The blackout in the Italian power system became within fewer than 3 minutes. 21:40 official announcement about emergency cancellation in whole power system of Italy. Main causes of the blackout in Italy The initial event was the 380-kV line tripping in Switzerland in consequence of the wire the tree contact. The attempts of single-phase auto-reclosing and also attempt of the operators to put this line back into operation were not successful and the line was disconnected by its protection device, because phase angle was too high. We can see two causes: †¢ insufficient protective zone under the transmission lines. †¢ overloaded lines. After the first 380 kV line tripping in the Swiss power system other power lines became overloaded. That means that the safety N-1criterion was non fulfillment in the Swiss power system. We can see other causes: †¢ Violation of basic safety N-1criterion. †¢ high import to Italy. †¢ incomplete information about neighboring power system. †¢ pump load was stopped too late, by automatics. 1.1.2. System disturbance in the UCTE system on 4 November , 2006 The system disturbance in the UCTE system on 4 November, 2006 was the most serious incident in the UCTE system within an interconnected Europe history. The system disturbance started in the German transmission system on 4 November 2006, around 10 p.m. This disturbance split the UCTE system into three separate parts (West, North-East and South-East). More than 15 million households were affected by an interruption of the electricity. The UCTE system resynchronization was completed 38 minutes after the splitting. [4] What happened? On 18 Sept. 2006, the shipyard (Meyerwerft) sent a request to E.ON Netz to disconnect two 380 kV line Conneforde-Diele for the transport of the ship through the Ems River to the North Sea on 5 November at 01:00. As a switching in the last several times. The E.ON Netz operator did a power flow calculation and verified fulfillment of safety N-1criterion using numerical computation. Analysis did not show any problem and so the operator provisionally approved the request of the shipyard and informed neighbouring transmission system operators (RWE Germany and TenneT Niederland). On 3 November (around 12.00) came a new request to E.ON Netz for a time change of two power lines Conneforde- Diele switching on 4 November at 22:00. A provisional agreement was given by E.ON Netz after a new analysis. But RWE and TenneT operators were not informed about this change at the same time. Only at 19:00 on 4 November E.ON Netz informed TenneT and RWE TSO about the new time for switching off the Diele -Coneforde line. At 21:29 according to the load flow calculation made by E.ON Netz did not indicate any violation of limit values. But N-1criterion was checked without numerical computation, was checked based on an empirical evaluation of the grid situation only. Sequence of events †¢ At 21:38 a 21:39. power lines Conneforde-Diele were disconnected. †¢ At 21:39. after the switching operation, two 380 kV lines was overloaded. †¢ At 21:41. RWE dispatcher informed E.ON Netz about the safety limit value on the line Landesbergen-Wehrendorf (an interconnection line between E.ON Netz and RWE TSO). Later investigation uncovered different protections setting on this line. †¢ Between 22:05 and 22:07, the load on the 380 kV line Landesbergen-Wehrendorf increased and the RWE operator called E.ON Netz at 22:08 with the request for urgent intervention due to return to the stable grid condition. †¢ E.ON Netz made an empirical assessment of corrective switching measures without making load flow estimation for checking the N-1criterion. E.ON Netz expected that coupling of the bus-bars in the substation of Landesbergen would reduce of load on the 380 kV line Landesbergen- Wehrendorf. But this line was overload more than 100% and so was tripped and the other lines became overloaded. †¢ At 22:10:28 the UCTE system splitted to three areas after the power lines switching in E.ON Netz, RWE, the Austrian power system and after disconnection of interconnection lines: Croatia Hungary and Marocco -Spain. The initial event of the system disturbance in the UCTE system was scheduled switching off two power lines. Main causes The investigation identified two main causes of the disturbance as well as some critical factors which had significant influence on its course: non fulfillment of the N-1criterion or verified its fulfillment without numerical computation. †¢ insufficient co-ordination between the transmission system operators. †¢ dissatisfied power plant operation in emergency: tripping of generation units (particularly wind power plants) during disturbance and uncontrolled reconnection of generation units. †¢ limited range of action available to dispatchers. †¢ insufficient training of dispatchers. 1.2. Blackout Causes and Risks A blackout is a power outage. This state means the loss of the electricity supply for a part of the power system or the whole power system. A. Blackout Causes Natural causes Lightening. Rain. Snow. wind storm. Technical Failures Transformer faults. Short circuits. Human error Error of judgment. Insufficient co-ordination between the transmission system operators. Insufficient training of dispatchers. Terrorism Bombing. cyber-attacks. B. Blackout Risks power system equipment damage. heavy economical losses. jeopardy of economy functioning. life paralysis in stricken parts of country. Several blackouts cases became in the world of last years. Causes of these disturbances were various technical, bad weather conditions, human failing. C. Some impacts of Northeastern Blackout Ford Motor Company The stoppage of factorys furnace cause to convert the molten metal to solid metal. The company reported that it need a week to clean the furnace. Marathon Oil Corporations The blackout was responsible for making suddenly shutdown procedures at Marathon refinery. in those procedures, a carbon monoxide boiler failed to shut down correctly, causing a small explosion. As a precautionary measure, the police vacate one-mile sector around the complex. Daimler Chrysler Daimler Chrysler lost production at 14 of its 31 factories. 6 of those were assembly factories with paint shops. The company reported that, in total, 10,000 vehicles were moving through the paint shops during the blackout had to be scrapped. New York City New York Citys mayor estimated that the city would pay almost USD 10 m in overtime related to the outage. Airports Airports were closed in Toronto, Newark, New York, Montreal, Islip, Cleveland, Erie and Hamilton. Together they cancelled over 1,000 flights 2.1. Introduction Under steady state conditions the power generation and the load are balanced and the power systems operate in nominal frequency 50 Hz or 60Hz with some deviations 0.02Hz for the large system and 0.05 for the small system. Taking into consideration the two-machines shown in Fig. 2, the power transmitting can be denoted by the following equation: Where: ES is the voltage of machine S ER is the voltage of machine R ÃŽÂ ´ is the angle by which ES leads ER = QS-QR QS is the rotor angle of machine S QR is the rotor angle of machine R ZT is the total impedance between the two machines consisting of ZS, ZR, and ZL ZS + ZL + ZR ZS is the impedance of source S ZR is the impedance of source R ZL is the impedance of the transmission line The Power angle curve in Figure 3 clears the relation between the power transmit and the angle ÃŽÂ ´ (the angle between the two ends). The relation clear that the power transmit increase with nonlinear direct proportion with the angle ÃŽÂ ´ when ÃŽÂ ´ lie between 0 ° : 90 ° . After ÃŽÂ ´ equal 90 ° the power decrease with nonlinear inverse proportion with the angle ÃŽÂ ´. The power system are worked well at the point of maximum power at ÃŽÂ ´ = 90 ° so The maximum power is presented as the following equation: Power Swing definition It is a changing in the Electrical power due to the changing of the rotor angle (ÃŽÂ ´) either Increasing or decreasing response to : line switching, Load disturbances , loss of generation, short circuit faults and other power system disturbances. During the large disturbance in the power system the transmit electric output power suddenly decreased from P0 to Pf as shown in Fig.4 but the mechanical torque (that connected to the generator and equivalent to the output electrical power P0 at the moment before reducing the electrical power) cant reduce suddenly to equivalent Pf so this unbalance cases accelerating in the rotor of the machine and increasing in the angle (ÃŽÂ ´). The assume of this analysis is neglects the operation of the voltage regulator that control on the excitation and change the machine voltage, and the governors that change the mechanical input power If the fault is cleared at the point of ÃŽÂ ´c the output electric power will increase and become greater than the input mechanical power so the machine will start to decelerate but because of the inertia the machine rotor cant decrease suddenly and reached to ÃŽÂ ´e. Assume area 1 refer to the accelerating energy, and area 2 refer to decelerating energy, so when the fault cleared quickly the two areas can be equal before the angle reach to the limiting angle ÃŽÂ ´L and the system will return after some oscillation to the last operating point at ÃŽÂ ´0 and that call Stable power swing. On the other side if the fault didnt clear quickly and spend more time, the angle ÃŽÂ ´ will move far away enough to make the two areas (accelerating area de accelerating area) not equal before the angle reaches to ÃŽÂ ´L as shown in Fig. 5 and due to the inertia the the angle will reach to the limiting angle and after this point the electrical output power will decrease again to be less than the mechanical input power so the machine rotor will accelerate and the rotor angle will increase above 180 and the pole slipping will happen . this case called out of step condition or unstable power swing condition Power Swing Effect on the Distance Relay Under Steady State Operation the impedance of the load not enter into the operation characteristic of the distance relay but in the case of power swing the load impedance may enter into the operation characteristic of the distance relay and case unwanted tripping for the transmission lines, and may be cause cascading tripping and stoppage of major sections of the power system. The distance relay isnt supposed to tripe under the power swing if stable or unstable to give the system the availability to return to its steady state. A power swing block PSB its a function inside the modern distance relays that prevent unwanted tripping by block the tripping signal in case of stable or unstable power swing thus, The Power Swing Block function is used to differentiate between the power swing and the fault. However, when the fault happens due to a Power swing it must be cleared very rapidly with high level of dependability and selectivity. The zones must be separated hoping to avoid causing large deference of the rotor angle between groups of the generators and loss the synchronism between them, equipment damage and the blackouts. Perfectly, the power system should be separated into predetermined zones to achieve a balance of load-generation in each of the separated zones. In some cases, load shedding is essential to avoid a whole blackout of the area where the load of the separated area is more than the local generation Controlled tripping of the power system relays in the case of an Out-of-Step condition is very essential to prevent extensive outages, equipment damage and shutdown of large areas in the power system. Out-of-step trip (OST) in is a function that included in the modern relays to achieve the separation of the power system under the unstable power swing. The major aim of this function to differentiate between the stable and unstable power swing and separate the power system into predetermined zones to achieve the stability and continuity of the service. Power Swing Detection Methods. Following is a brief discussion of the methods that have been used for detecting power swings and schemes used for OSB and OST functions. Traditional method based on rate-of change of impedance and the recently method is Power-Swing-Detection Algorithm Based on Continuous Impedance Calculation. 2.2.1 Traditional Rate of change of Impedance Schemes for Detecting Power Swings. In the conventional method, the relay measure and calculate the positive sequence impedance and the change rate of the impedance. During the steady sat operation the measured impedance depends on the load impedance and the distance between the protection zone of the distance relay and the point of measurement. The impedance move in trajectory depends on the operation case. In the case of the fault if the impedance moved rapidly to the fault zone. On the other case during the power swing the impedance moved slowly at some trajectory with a rate depend on the slip frequency between the generators. Thus, the variation of the impedance movement speed used to distinguish between the power swing and the faults. The concept of this method that using of two measuring impedance and separated them by ΆZ and used a calculated timer. When the measured impedance moved through the first one the timer will start running. If the measured impedance cross the second impedance before the time r expire, that indicated to a fault case. If the timer expired and the impedance didnt reach to the second impedance that indicated to a power swing case. Two-Blinder Scheme for PSB and OST Functions The two blinder scheme of the rate-of-change of impedance method is used in many relays, separated by ΆZ, and a calculated timer TOSB. The two-blinder scheme is shown in Fig. 7. This figure shows Two parallel blinders are on the right side of the X-line impedance and another two parallel blinders are on the left side. The timer TOSB is start running when the impedance move through the outer blinder During the fault condition the impedance moved rapidly through the outer blinder to the fault zone and cross the inner blinder before the TOSB expire. On the other case during the power swing the impedance moved slowly through the outer blinder and stay between the two blinders even TOSB will expire. This scheme can be used for a power swing blocking function to block the distance relay to prevent unwanted tripping. During Power Swing Blocking declared a reset timer should be used in order to force the relay to delay the assert when TOSB expired. The Out-Of-Step tripping (OST) can use the previous scheme expect that the calculated timer for out of step (TOST) is shorter than TOSB. In the case of power swing the impedance locus cross the outer blinder and at this point the timer will start running. If the timer TOST expires before the impedance locus cross the inner blinder, the power swing condition will declare, and if the impedance locus cross the inner blinder before timer TOST expires, the out of step condition will declare. The Out-Of-Step tripping function can be set to tripe instantly or wait for a time. The Instantly tripping referred to as predictive tripping or early tripping. The other case is referred to as delayed tripping. In some applications, the tripping is required only when the out of step condition occurs a determined number of times. It is essential for some application to use both OSB and OST functions, and it available to use them in the Same relays using the two blinder scheme technique. According to difference in speed of impedance trajectory in the case of stable power swing and unstable power swing, two timers are required TOSB and TOST whereas TOST is shorter than TOSB to be fit with the rapidly speed of the impedance trajectory in case of unstable power swing 2.2.2. Power Swing Detection Algorithm Based on Continuous Impedance Calculation The traditional methods of power swing detection are depend on a complex study for the power system to reach to the correct settings, but the setting are fixed and not adapt to any change in the system condition because of it is not possible to study the system under unstable power swing. therefore, the power system study doesnt deem the worst cases and the bad conditions, so in the case of power swing or out of step condition it may lead to unwanted tripping. The following method described below solves these problems. It is based on a continuous impedance calculation [5]. This method has the following features: It is not required for settings or complex calculation detect the power swing with frequencies range from 0.1: 10 Hz. Detect the power swing in the case of single-pole open condition or fault condition. Unblocking of distance protection relay if there both faults and power swing. Out-of-step tripping during unstable power swing. The Continuous Impedance Calculation method depend on taking four sample of the impedance per one cycle of the power system frequency the three phase each phase separately. During the power swing the impedance trajectory moved on an oval path, and when it enters the power swing area, as shown in Figure 8, the algorithm of power swing start its analysis for each phase and calculate the power swing area automatically. In the case of power swing, the power swing detection will detect it, and stay active even if the trajectory of the impedance leave the power swing zone. The algorithm computes the new values of R X, and compares them with the previous values that placed in the memory. The main criterias of the power swing detection methods are monotony, continuity and smoothness. The thresholds are calculated dynamically. This automatic adaptability to the trajectory speed change, enables the algorithm to detect the low frequency and the high frequency power swing. Monotony: The algorithm will check the direction of the derivat

Reader-Response on Soldiers Home Essay -- American Literature

Reader-Response on Soldier's Home The initial reaction I received from reading Soldier's Home, and my feelings about Soldier's Home now are not the same. Initially, I thought Harold Krebs is this soldier who fought for two years, returns home, and is disconnected from society because he is in a childlike state of mind, while everyone else has grown up. I felt that Krebs lost his immature years, late teens to early 20's, because he went from college to the military. I still see him as disconnected from society, because there isn't anyone or anything that can connect him to the simple life that his once before close friends and family are living. He has been through a traumatic experience for the past two years, and he does not have anyone genuinely interested in him enough to take the time to find out what's going on in his mind and heart. Krebs is in a battle after the battle. Imagine your hometown, a small, affluent community where everyone knows each other. This small community is where many of your childhood friends and some of your family also reside. If you left your hometown for a two-year period to go into the military, to go to college, to travel the world, or just to experience life somewhere else, how would you expect your friends and family to treat you when you arrived home after a two-year period? Would you expect a warm welcome from your love ones, would you expect to be able to share your experiences, or major events that took place in your life? Would you expect that everyone has changed at least a little bit, and you have changed somewhat as well? I definitely would not expect or would not want my friends and family to reject me, because I had changed due to my life experiences outside our sma... ...has failed to help him deal with his inner emotions from his military experience. He has been through a traumatic experience for the past two years, and he does not have anyone genuinely interested in him enough to take the time to find out what's going on in his mind and heart. Kreb's is disconnected from the life he had before the war, and without genuine help and care from these people he lived with, and around all his childhood life, it's difficult to return to the routines that everyone is accustomed to. Works Cited Hemingway, Ernest. "Soldier's Home." The Bedford Introduction to Literature, 6th Edition. Ed. Michael Meyer. New York: Bedford/St. Martin's. 2002. 152-57. "Reader Responses to Soldier's Home." Literature and Composition. 10 Feb.,2003. David Toth. 14 Feb., 2003. .

McDonald’s vs Burger King: Which is Healthier Essay

The United States has the largest fast food industry in the world, and American fast food restaurants are in over 100 countries. That alone tells you that millions of consumers partake in fast food. By definition, fast food is food that can be prepared and served very quickly. A typical fast food meal in the United States includes a hamburger, French fries, and a soft drink. Out of all of the fast food restaurants in the United States, there are two companies that comes to mind that are the biggest chains in the country. Those two fast food chains are Burger King and McDonald’s. These two companies own more than half of the fast food market in the U. S. With that said, in the past couple of years there has been concern over the obesity rate in the United States. People believe that fast food is a factor because of how easy it is to get it and the price range of it. Because of the perceptions of fast food, every one is looking to the biggest fast food chains to set the example and make their menus healthier. McDonald’s and Burger King are the two fast food chains trying to convert their menu to provide healthier foods, each in their own way. Before looking at the menus of both fast food chains, one has to understand the history. What made them who they are today? How was it created? When did it go public? The first restaurant is McDonald’s. In 1937, Patrick McDonald opened â€Å"The Airdome†, which was a food stand in Monrovia, California. Hamburgers were ten cents and all you can drink. In 1940, his two sons, Maurice and Richard, brought the food stand from their father and moved the entire operation 40 miles and changed the name to â€Å"McDonald’s Bar-B-Q† and served 25 barbecued items on their menu. In October 1948, the brothers realized that most of their profits came from selling hamburgers so they closed down the establishment. On December 12, 1948, the restaurant’s name was once again changed to â€Å"McDonald’s† and went to a menu of hamburgers, cheeseburgers, French fries, shakes, soft drinks, and apple pie. After 5 years of growing popularity and success the brothers decided to start franchising the restaurant. One year later, Ray Kroc, who sold Multi-mixer milkshakes machines, learned that one of the McDonald’s restaurants were using eight of his machines and he decided to take a look for himself. After meeting with the McDonald brothers, Kroc thought that they could franchise the restaurants throughout the country. The brothers did not think the same way so Kroc decided to take it upon himself to do so. By 1959, Kroc had 102 successful restaurants in the United States and by 1961 Kroc brought the business rights from the McDonald brothers for about three million dollars. Like McDonald’s, Burger King also has a long and rich history. It was founded in 1953 in Jacksonville, Florida as Insta-Burger King. Inspired by the McDonald brother’s original store location in San Bernardino, California, the founders and owners, Keith J. Kramer and his wife’s uncle Matthew Burns, began searching for a concept to open a new restaurant around. After purchasing the rights to two pieces of equipment called â€Å"Insta† machines, the two opened their first stores around a cooking device known as the Insta-Broiler. The Insta-Broiler over proved to be so successful at cooking burgers; they required all of their franchises to carry the device. With their new success in the way they cooked burgers, the company had rapidly expanded throughout the state of Florida until its operations totaled more than 40 locations in 1955. By 1961, Insta-Burger King ran into financial difficulties and the pair of McLamore and Edgarton purchased the national rights to the chain. It was rechristened as Burger King of Miami. The company would eventually become the Burger King Corporation and began selling territorial franchise licenses to private owners across the United States by 1961. As I stated in the beginning of my essay, I wanted to compare the two menus between Burger King and McDonald’s. Even though both restaurants are into selling hamburgers, how they are cooked and presented separate these two companies tremendously. For McDonald’s, they have added other items to their menu since the original restaurants opened back in 1948. They added a breakfast menu back in 1972 in which they sold certain breakfast sandwiches such as the McMuffin, which came in certain amounts of variations. There are also types of biscuits and breakfast burritos. Additional breakfast items include hotcakes, several breakfast platters with eggs, hash browns, and meats or breads. As you know, for lunch, McDonald’s serves many sandwich options such as the Quarter Pounder, the McDouble, which is the double cheeseburger, and chicken sandwiches, which they call a McChicken. The trademark sandwich for McDonald’s is called a Big Mac. It was introduced nationwide in 1968. It consists of two 100 percent beef patties, American cheese, â€Å"special sauce†, which is based off a Thousand Island dressing, iceberg lettuce, pickles, onions, and served in a three-part sesame seed bun. Other items on the menu consist of Chicken McNuggets, Chicken Selects, which is the McDonald’s version of chicken strips, Filet-O-Fish, and a McRib, the McDonald’s Rib Sandwich. Burger King’s menu predominantly consisted of hamburgers, French fries, soft drinks, milkshakes, and desserts. In 1978, the company introduced the first iteration of its breakfast menu. The breakfast menu remained almost identical to the McDonald’s offerings until 1983 when Burger King introduced its Croissan’Wich, which comes in many variations like the McDonald’s counterpart, McMuffin sandwich. For the lunch menu, there is little difference between the Burger King and McDonald’s Menu. The counterpart of McDonald’s Chicken McNuggets is called the BK Chicken Tenders, which made its debut in 1985. For Burger King, they have two trademark sandwiches. The first one is the counterpart of the McChicken, which Burger King calls the BK Original Chicken Sandwich. It made its debut in 1978. The other sandwich is called the Whopper. Introduced in 1957, it is one of the best known sandwiches in the fast food industry. The Whopper consists of a flame grilled quarter-pound beef patty, sesame seed bun, mayonnaise, lettuce, tomato, pickles, ketchup, and sliced onion. Now we get to the meat of the conversation. Both companies have been trying to add healthier choices to their menu for years now. For example, McDonald’s had to battle its public image as a purveyor of fatty, unhealthy food. Consumers began filling lawsuits contending that years of eating at McDonald’s had made them overweight. So in 2003, McDonald’s introduced a low calorie menu of low-calorie items and they also switched to more healthful cooking oil for the French fries. Burger king is no different to the criticism of their food. Since the 1980s, several parties, including the Center for Science in the Public Interest, the British Heart Foundation and the City of New York argued that Burger King has contributed to obesity and unhealthy eating behaviors in Western nations by producing products that contain large amounts of salt, fat, trans-fat, and calories. With that said, it is common knowledge that neither McDonald’s nor Burger King is the healthiest option if you are trying to maintain a healthy lifestyle. Let’s examine at the major items that both of these fast food chains provide and see which one is healthier. Starting with the French fries, a medium order from Burger King will make the customer consume 400 calories, 20 grams of fat, 43 grams of carbohydrates and 5 grams of protein. The same amount for McDonald’s will provide 20 calories, 7 grams of fat, 19 grams of carbohydrates, and 3 grams of protein less than Burger King’s French fries. So apparently McDonald’s wins in French Fries, for cheeseburgers, McDonald’s are not only lower in calories versus Burger King at 300 to 360, but also in fat and carbohydrates as well. They are also significantly higher in protein. Now for the main event, the Big Mac versus the Whopper, both of these burgers are the most popular menu item for both of these respected fast food chains. Which one is healthier? The Big Mac contains 540 calories, 29 grams of fat, 45 grams of carbohydrates and 25 grams of protein. The Whopper, on the other hand, contains 670 calories, 39 grams of fat, 51 grams of carbohydrates, and 27 grams of protein. So in other words, the Big Mac is Healthier. After looking at the other items that Burger King and McDonald’s provides head to head, Burger King has the edge in terms of its chicken products. Now the big question is who has the healthiest menu? To be honest, it depends on the menu item you choose to buy from either one of these food chains. If you want a good burger that will not do that much damage to your diet then McDonald’s is the way to go. If you are looking to eat a Chicken Sandwich, it looks like the Burger King should change their name. In conclusion, when asking the question of which fast food chain is healthier it is safe to say that there is no clear-cut answer. Even through McDonald’s, when looking at the nutritional stats of each item compared to Burger King, wins in the Burger section. We as consumers have to realize that â€Å"fast food† is not healthy in the first place. These two fast food chains have rich and interesting histories that contributed to how and what they sell to their customers. Each menu has been tweaked in order to fulfill the needs of the consumer over the years. Every consumer prefer to have their own method of buying items, so the best advice I can give is to do your own research beforehand. It is also important to show that you should limit the amount of fast food you eat on a regular basis in order to maintain a healthy lifestyle.

Heart Dissection Practical Report Essay

Introduction On the of July 2002, a sheep’s heart was examined by dissection. The heart is a muscle in all mammalian bodies that is used to pump blood and nutrients throughout the body. A sheep’s heart was used in this prac because like the human heart it has four chambers and is similar in size. Two of these chambers are receiving chambers called the left and right atrium. The other two are pumping chambers called the right and left ventricle. The reliability of the cycle of blood through the body depends on the sequence of contractions from the atrium and the ventricle. When ever the atriums contract it is called the systolic phase. And when ever the ventricles contract, it is called the diastolic phase. These sequences ensure the blood flow through the heart. These occur one after the other to create a heart beat. The blood flow through the heart starts when the right atrium takes the blood that flows through the superior or inferior vena cava. The right atrium then fills with blood and the pressure of the blood causes the tricuspid valve to open. The blood then travels through into the right ventricle where it pusses the blood into the pulmonary arteries. After this the blood is pumped into the lungs where it is oxygenated, the oxygenated blood travels through the left ventricle then pushes the blood through the aorta, which provides the body with blood. Aims The aims and goals of this procedure was to: 1.Dissect and examine a mammalian heart 2.Develop dissection skills 3.An in-depth investigation into how the heart works. Materials Materials used in this dissection were: 1.Sheep’s heart 2.Scalpel 3.Rubber gloves 4.Dissection tray 5.Paper Procedure The first step in the dissection is to put on the rubber gloves before handling the raw hearts. Next was to place the sheep heart on the dissection tray. After that an exterior examination happened to detect the mail valves. Next was to locate a fatty area on the heart to help guide the first incision into the heart. Two incisions were required during the procedure. The first one was to be parallel to the right ventricle. The incision must be deep enough to cut into the ventricle to be able to get a proper view. The second was opposite the first to examine the other side of the heart, to be able to view the chordae tendinae. After the dissection is completed, the heart must be properly disposed along with the gloves and hands must be washed. Results diagram of heart valve system Discussion During the dissection of the sheep heart, features of the muscle were detected. One of these was that the left ventricle wall was thicker then the right ventricles. This is because it uses this extra muscle to propel the blood through the aorta to the rest of the body. Also some stringy substances holding a kind of flap was found, this was soon made clear that it was the chordae tendinae. It is attached to the bicuspid valve and capillary muscle and had a remarkable strength because it had to work hard in a high-pressure area and hold the heart tougher. Also in this region, the heart wall was wetter and slipperier then the rest of the heart. This was for extra lubrication. The flow of blood was made clearer when the heart was opened up. Diagram of path of blood flow through the heart. The direction of blood flow through the heart starts from superior or inferior vena cava to the right atrium. Then it passes through the tricuspid valve into the right ventricle to the pulmonary arteries. The blood then goes to the lungs where it is oxygenated comes back down to the pulmonary veins to the left atrium, then passes through the bicuspid valve into the left ventricle where it is propelled through the aorta into the body.