Quiz Review Dark Romanticism Essays - Fiction, Literature

Quiz Review Dark Romanticism: Top of Form Read the excerpt from the beginning of Chapter 5 of Little Women , by Louisa May Alcott. "What in the world are you going to do now, Jo?" asked Meg one snowy afternoon, as her sister came tramping through the hall, in rubber boots, old sack, and hood, with a broom in one hand and a shovel in the other. "Going out for exercise," answered Jo with a mischievous twinkle in her eyes. "I should think two long walks this morning would have been enough! It's cold and dull out, and I advise you to stay warm and dry by the fire, as I do," said Meg with a shiver. "Never take advice! Can't keep still all day, and not being a pussycat, I don't like to doze by the fire. I like adventures, and I'm going to find some." Why does Alcott most likely begin the chapter with character dialogue? to introduce the characters in the story to set up the problem in the story to establish the mood of the story to keep the momentum of the story going Bottom of Form Top of Form Read the excerpt from "The Adventure of the Mysterious Picture." "[T]here is a secret about one of my rooms on which I feel disposed to try an experiment. So, gentlemen, none of you shall know who has the haunted chamber, until circumstances reveal it. I will not even know it myself, but will leave it to chance and the allotment of the housekeeper. At the same time, if it will be any satisfaction to you, I will observe, for the honor of my paternal mansion, that there's scarcely a chamber in it but is well worthy of being haunted." What technique does Irving use to build suspense in the excerpt? The pace of the story quickens. The word choice darkens the tone. Odd characters are introduced. Setting details are intentionally omitted. Bottom of Form Top of Form Read the excerpt from the beginning of Chapter 1 of Treasure Island, by Robert Louis Stevenson. SQUIRE TRELAWNEY, Dr. Livesey, and the rest of these gentlemen having asked me to write down the whole particulars about Treasure Island, from the beginning to the end, keeping nothing back but the bearings of the island, and that only because there is still treasure not yet lifted, I take up my pen in the year of grace and go back to the time when my father kept the Admiral Benbow inn and the brown old seaman with the sabre cut first took up his lodging under our roof. Which best explains Stevenson's reason for beginning the chapter with this paragraph? Stevenson creates confusion in the reader with a narrator who explains that he is writing a story because he has been asked to do so by several other characters. Stevenson creates interest in the reader with mention of still undiscovered treasure and the arrival of a mysterious character in the narrator's life. Stevenson creates unease in the reader with a detailed account of the problem the main character has to overcome to reach a solution. Stevenson creates a clear visual picture in the reader's head with a strong description of the story's setting without giving its actual location. Bottom of Form Top of Form Which event described in chapter 1 of The Scarlet Letter takes place before the story begins? The crowd discusses Hester's crime. The crowd walks to the scaffold. The Puritans elect officials. The Puritans erect a jail. Bottom of Form Top of Form Read this excerpt from chapter 2 of The Scarlet Letter . Standing on that miserable eminence, she saw again her native village , in Old England, and her paternal home; a decayed house of gray stone , with a poverty-stricken aspect, but retaining a half-obliterated shield of arms over the portal, in token of antique gentility . What is the effect of the underlined words in this excerpt? They impart a frustrated mood. They impart a sympathetic mood. They portray a former setting with humility and dignity. They portray a former setting with judgment and distaste. Bottom of Form Top of Form Read this excerpt from chapter

The Individual European essays

The Individual European essays The individual European has altered in many ways throughout the ages. From the Middle Ages all the way through the enlightenment, the world, religion, God, and life and death have gone through courses of many changes. During the period of the middle ages, the world was thought to be evil and filled with temptation. As a result, the world turned inwards during this time. Knowledge of the outside world was not recognized and did not want to be known. The world became centered in daily life in view of the fact that an individual European from the middle ages thought that the outside world was foreign and dangerous. However, when the Renaissance came about, the world gradually turned outwards. The world began to examine what is on the outside of itself, and discover itself. From the reformation all the way to the enlightenment, the mind of the common European shifted in a positive direction. All through the reformation and the enlightenment, the outside world was no longer viewed as diabolical or dangerous. Life and the way Europeans lived changed with time as well. During the period of the middle ages, only designated fairs and celebrations such as, May Day, Feast of Fools, holydays, and the Tow n Faire, which provided news to the locals, tempered daily life. It was also thought that the only dependable aspect of life was religion. Life consisted on where you were born, or to what family you were born into. This is what decided what your future would entail. Life in town was very separate from the outside world. A massive wall and a castle as the focal point surrounded the town. In the renaissance era, however, more people moved to cities and towns, wealth seeped into middle class, and more education and better standards of living were sought. There was a dramatic change in the lives of the individual European in the reformation and the enlightenment era. Life now included happiness and the ability to succeed and be ...

P-39 Airacobra - Bell Aircraft - World War II

P-39 Airacobra - Bell Aircraft - World War II P-39Q Airacobra - Specifications General Length: 30 ft. 2 in.Wingspan: 34 ft.Height: 12 ft. 5 in.Wing Area: 213 sq. ft.Empty Weight: 5,347 lbs.Loaded Weight: 7,379 lbs.Maximum Takeoff Weight: 8,400 lbs.Crew: 1 Performance Maximum Speed: 376 mphCombat Radius: 525 milesRate of Climb: 3,750 ft./min.Service Ceiling: 35,000 ft.Power Plant: 1 Ãâ€" Allison V-1710-85 liquid-cooled V-12, 1,200 hp Armament 1 x 37 mm M4 cannon2 x .50 cal. machine guns4 x .30 cal machine gunsup to 500 lbs. of bombs Design Development In early 1937, Lieutenant Benjamin S. Kelsey, the US Army Air Corps Project Officer for Fighters, began to express his frustration over the services armament limitations for pursuit aircraft. Joining with Captain Gordon Saville, a fighter tactics instructor at the Air Corps Tactical School, the two men wrote two circular proposals for a pair of new interceptors which would possess a heavier armament that would allow American aircraft to dominate aerial battles. The first, X-608, called for a twin-engine fighter and would ultimately lead to the development of the Lockheed P-38 Lightning. The second, X-609, requested designs for a single-engine fighter capable of dealing with enemy aircraft at high altitude. Also included in X-609 was a requirement for a turbo-supercharged, liquid-cooled Allison engine as well as a level speed of 360 mph and an ability to reach 20,000 feet within six minutes. Responding to X-609, Bell Aircraft began work on a new fighter that was designed around the Oldsmobile T9 37mm cannon. To accommodate this weapon system, which was intended to fire through the propeller hub, Bell employed the unorthodox approach of mounting the aircrafts engine in the fuselage behind the pilot. This turned a shaft beneath the pilots feet which in turn powered the propeller. Due to this arrangement, the cockpit sat higher which gave the pilot an excellent field of view. It also allowed for a more streamlined design which Bell hoped would aid in achieving the required speed. In another difference from its contemporaries, pilots entered the new aircraft through side doors that were similar to those employed on automobiles rather than sliding canopy. To supplement the T9 cannon, Bell mounted twin .50 cal. machine guns in the aircrafts nose. Later models would also incorporate two to four .30 cal. machine guns mounted in the wings. A Fateful Choice First flying on April 6, 1939, with test pilot James Taylor at the controls, the XP-39 proved disappointing as its performance at altitude failed to meet the specifications set forth in Bells proposal. Attached to the design, Kelsey had hoped to guide the XP-39 through the development process but was thwarted when he received orders that sent him abroad. In June, Major General Henry Hap Arnold directed that the National Advisory Committee for Aeronautics conduct wind tunnel tests on the design in an effort to improve performance. Following this testing, NACA recommended that the turbo-supercharger, which was cooled with scoop on the left side of the fuselage, be enclosed within the aircraft. Such a change would improve the XP-39s speed by 16 percent. Examining the design, Bells team was unable to find space within the XP-39s small fuselage for the turbo-supercharger. In August 1939, Larry Bell met with the USAAC and NACA to discuss the issue. At the meeting, Bell argued in favor of eliminating the turbo-supercharger altogether. This approach, much to Kelseys later dismay, was adopted and subsequent prototypes of the aircraft moved forward utilizing only a single-stage, single-speed supercharger. While this alteration provided the desired performance improvements at low altitude, the elimination of the turbo effectively made the type useless as a front-line fighter at heights above 12,000 feet. Unfortunately, the drop-off in performance at medium and high altitude was not immediately noticed and the USAAC ordered 80 P-39s in August 1939. Early Problems Initially introduced as the P-45 Airacobra, the type was soon re-designated P-39C. The initial twenty aircraft were built without armor or self-sealing fuel tanks. As World War II had begun in Europe, the USAAC began to assess combat conditions and realized that these were needed to ensure survivability. As a result, the remaining 60 aircraft of the order, designated P-39D, were built with armor, self-sealing tanks, and an enhanced armament. This added weight further hampered the aircrafts performance. In September 1940, the British Direct Purchase Commission ordered 675 of the aircraft under the name Bell Model 14 Caribou. This order was placed based on the performance of the unarmored and unarmed XP-39 prototype. Receiving their first aircraft in September 1941, the Royal Air Force soon found the production P-39 to be inferior to variants of the Hawker Hurricane and Supermarine Spitfire. In the Pacific As a result, the P-39 flew one combat mission with the British before the RAF shipped 200 aircraft to the Soviet Union for use with the Red Air Force. With the Japanese attack on Pearl Harbor on December 7, 1941, the US Army Air Forces purchased 200 P-39s from the British order for use in the Pacific. First engaging Japanese in April 1942 over New Guinea, the P-39 saw extensive use throughout the Southwest Pacific and flew with American and Australian forces. The Airacobra also served in the Cactus Air Force which operated from Henderson Field during the Battle of Guadalcanal. Engaging at lower altitudes, the P-39, with its heavy armament, frequently proved a tough opponent for the famed Mitsubishi A6M Zero. Also used in the Aleutians, pilots found that the P-39 had a variety of handling problems including a tendency to enter a flat spin. This often was the result of the aircrafts center of gravity shifting as ammunition was expended. As distances in the Pacific war increased, the sh ort-range P-39 was withdrawn in favor of increasing numbers of P-38s. In the Pacific Though found unsuitable for use in Western Europe by the RAF, the P-39 saw service in North Africa and the Mediterranean with the USAAF in 1943 and early 1944. Among those to briefly fly the type was the famed 99th Fighter Squadron (Tuskegee Airmen) who had transitioned from the Curtiss P-40 Warhawk. Flying in support of Allied forces during the Battle of Anzio and maritime patrols, P-39 units found the type to be particularly effective at strafing. By early 1944, most American units transitioned to the newer Republic P-47 Thunderbolt or North American P-51 Mustang. The P-39 was also employed with the Free French and Italian Co-Belligerent Air Forces. While the former was less than pleased with the type, the latter effectively employed the P-39 as a ground-attack aircraft in Albania. Soviet Union Exiled by the RAF and disliked by the USAAF, the P-39 found its home flying for the Soviet Union. Employed by that nations tactical air arm, the P-39 was able to play to its strengths as most of its combat occurred at lower altitudes. In that arena, it proved capable against German fighters such as the Messerschmitt Bf 109 and Focke-Wulf Fw 190. In addition, its heavy armament allowed it to make quick work of Junkers Ju 87 Stukas and other German bombers. A total of 4,719 P-39s were sent to the Soviet Union through the Lend-Lease Program. These were transported to the front via the Alaska-Siberia ferry route. During the course of the war, five of the top ten Soviet aces scored the majority of their kills in the P-39. Of those P-39s flown by the Soviets, 1,030 were lost in combat. The P-39 remained in use with the Soviets until 1949. Selected Sources Military Factory: P-39 AiracobraNational Museum of the US Air Force: P-39 AiracobraAce Pilots: P-39 Airacobra

Data Warehouse Essay Example | Topics and Well Written Essays - 750 words

Data Warehouse - Essay Example The data warehousing is a multi-task activity and it quite different from traditional transaction-oriented operational database management activity. It involves various state – of – art application tools and techniques for aggregating and thereby summarizing large amounts of data that assists in an effective data management and retrial. A state-of-the-art application in the data warehousing is one that can achieve a near-real-time situation. Most organizations call for immediate decision-making, which needs real-time analysis, and presentation of decision-making. Many data warehouse applications achieve this by shortening the loading cycles using micro batch ETL. These applications have unique characteristics which include: highly scalable data mining algorithms, ease of integration with other components, efficient and secure in database processes, ease of use and user-friendliness and can support relevant standards. It is, however, important to have proper consideratio ns while choosing the methodology to use in the implementation of the applications and also the entire system. Two options are available. Both of the approaches have both advantages and disadvantages; therefore, the organization should consider the individual components and the nature of activities before deciding which approach to use. In any case, it is important to consider factors such as the volume of work, user technical skills, availability of budget and the time available to carry out the activity. (Prabhu, and Venkatesan, 20). What Have Been Notable Successes that We Can Emulate? There are numerous notable success stories of organization that can be emulated. One of such stories is Hallmark Cards. Hallmark Cards with $3.6 billion in annual sales and 20,000 employees, is a leader in the personal expressions industry. It has approximately 40,000 products selling through over 40,000 retail outlets. Since as a personal expression industry, it was very critical for the company business to understand what is happening at retail outlets in order to react quickly to changes in the environment. Hallmark utilized the warehouse environment with data mart along with decision support system (DSS) to help his management to understand market environment to launch a major new product line. By using data mart,

Strategic Management Assignment Example | Topics and Well Written Essays - 3750 words

Strategic Management - Assignment Example With the imminent move toward internationalisation and liberalisation of industry, organisations need to be equipped with the rapid alterations in the business forces. Hence, every company require adjusting with the varying demand of customers as well as variations in the business environment. It is in this context that change is the response of business and other economic occurrences. Change is the procedure of administrative awareness, selection of alternatives and implementation of new or modified functions where managers view certain actions taking place, representing the requirement of change (Rashid & et. al., 2004). The change procedure in modern organisations is exclusive from every perspective owing to the differences prevailing in terms of the culture, i.e. the type of trade, the working environment, the values and principles, the administration and leadership style and the behaviours as well as approach of current employees. Additionally, there is risk of failure as people are generally observed to behave as resistant to the change being implemented or even those which are occurring spontaneously. For some people change can give pleasure, bliss and benefits, while for others, change can bring discomfort, pressure and difficulties (Rashid & et. al., 2004). Among all other factors, the most influential aspect which can create a vast impact on change is the organisational culture (Rashid & et. al., 2004). With due consideration to these prospects, the paper assesses how organisational culture creates an impact on the manner organisational change is embraced or resisted by the employees. Defining Organisational Culture The conception of organisational culture is extensively used in modern day organisations in order to define the environment and working practices which have been developed in order to manage the employees and at large preserve the smooth commencement of business operations. IT is in this context that organisational culture encourages moral e amid employees and statement of principles of a particular company. It is the duty of leaders being the prime executers in an organisation, to develop an effective culture according to the working procedure. It is also their sole responsibility to extinguish a particular culture when it becomes obsolete (Donnell & Boyle, 2008). Culture in any organisation provides the feeling of distinctiveness and defines the organisational traditions, customs, principles, meanings, values, standards and the way determined objectives are achieved in organisations. The culture summarises the positive performances and traditions which was worked in the past. These performances are accepted by long-serving employees in an organisation. Furthermore, the foremost concern a new employee acquires about an organisation is the culture. Culture remains in organisation and becomes a part of its conventional manner of conducting works. Over the years, organisations also develop standards, i.e.

Design of Wind Turbine Control

Design of Wind Turbine Control ABSTRACT The main objective of this report is the design and analysis of the control of the wind turbine. In order to ensure an efficient energy capture from the wind and at the same time the mitigation of loads at natural frequencies, it will be designed the operating strategy of the machine. Furthermore, the control of the wind turbine will be also designed in order to ensure a stable performance of the system given the stochastic nature of the wind. As a last task, it will be analysed the differences and importance of having a system with a good or reduced crossover frequency. Introduction The exploitation of wind energy is undoubtedly the most popular tool for the tackling of climate change all over the world. The development of wind turbines has led to a variable speed pitch regulated configuration that aims to extract energy from the wind as efficiently as possible. As the penetration of wind energy becomes more and more significant in modern power systems, there is a need to meet certain criteria and quality of generation in order to maintain the reliability and security of supply above certain levels. In order to achieve an optimize energy capture and prevent the machine from excessive loads, the design of both operating strategy and controller of the plant need to be carried out. The difficulty of the design relies on the stochastic nature of the wind, so a carefully and detailed approach is needed. Also, as the controller of the turbine is the heart of its operation, the design of this will become more and more difficult with the size of the turbine [1]. The larger the turbine, the more structurally flexible the mechanical parts will become and it is at this point where the fatigue loads become a major concern, as they are closely related to the operating life of the machine and also to the operational and maintenance costs. The purpose of this report is to highlight the importance of the controller and the contribution to the energy capture, as well as the design of a suitable operating strategy that maximized the reduction of loads while ensuring an efficient performance. 2.1 Baseline and procedure The main objective of the control design of any wind turbine is to obtain a good trade-off between energy and loads. In variable speed pitch regulated turbines it is controlled both pitch and torque. The former is controlled to limit the aerodynamic power in above-rated power (hence, the loads), while the latter is primarily used to control the transmission torque in above rated wind speeds and to maximize energy capture below the rated power region. The operating strategy must be carefully design in order to achieve maximum power capture while limiting the aerodynamic loads in the mechanical parts of the wind turbine, as they are critical aspects of the lifetime of the machine. Therefore, the design of the operating strategy must include load reduction as an explicit objective. In this report, the design of the operating strategy has been carried out with a special focus on the control of the tower and drive train resonances, as well as the mitigation of the blade loads. In order to design the operating strategy, it has been provided a model of a 1.5 MW variable speed, pitch regulated turbine. In the model, it was obtained the mechanical characteristics of the machine (Blade length, Gearbox ratio and so on), along with the power coefficient values for below rated operation, where the pitch of the blades was -2 degrees and is fixed for below rated operation. With the above data, it was possible to set the Cp-ÃŽÂ » curve of the machine. This type of curves are used in wind turbine design to obtain rotor power for any combination of rotor and wind speed. By building this curve it is possible to obtain the maximum power capture. This is given by the power coefficient Cp, that it is a relationship between the power in the wind stream and the power generated by the turbine [2]. The desired operating strategy must try to achieve the maximum power capture, and hence the maximum value of Cp, and such operating point determines the optimum tip speed ratio ( ÃŽÂ »), which is the ratio between the rotor speed and the wind speed. Once the optimum point of power extraction is set, it is possible to build the model of the machine. For this machine, the generator will operate in a range between 1 rad/s and 170 rad/s. Therefore, having the gearbox ratio, it is possible to obtain the rotor speed given the following equation: By obtaining the range of rotor speeds of the machine, it can now be calculated the necessary wind speed for each rotor speed with the following equation: Where ÃŽÂ » represents the optimum tip speed ratio of the machine, which corresponds to a value of 8.4 in this design (for a Cpmax of 0.47). This range of wind speeds is used to obtain the aerodynamic torque, which is a function of the rotor speed and wind speed (when the pitch angle is fixed). Therefore, it is possible to derive the aero torque by the following equation: Where the values of and correspond to the optimum operating point. That is, for a given wind speed and rotor speed, the objective is to produce a torque such that the power extraction from the wind is maximum. Thus, the above equation will provide the torque values for the maximum energy tracking region. On the other hand, it is necessary to obtain the generator torque, as this will be used in order to determine the end of the first and second constant speed (To and T1). As it can be seen in the equation below, the damping losses have been considered. For this design, a damping of 5 has been assumed. The generator toque can be obtained by the following equation. Now it is possible to obtain the power generated in the machine by having an efficiency of 95% in this machine: And the torque at rated power of the machine is given by: The point where the rated power curve crosses with the second constant speed line, will determine the torque which will be generating at above rated operation. Finally, it has been calculated the values for the constant speed curves of the operating strategy. It has been applied equation 2.3, setting the wind speed constant (from 4 m/s to 12m/s) and calculated the torque for the different values of Cp and ÃŽÂ ». The resulting operating strategy will be such that will cross every constant wind speed by the point at which is the optimum power extraction point (Cpmax). 2.2 Operating strategy process Several factors must be considered in an operating strategy design. Having obtained the values in the previous section, it is possible to plot the maximum power extraction curve. The design must have special focus on the natural frequencies of the tower and blades. For this design, it has been provided the natural frequencies of both components. For the tower, the side-side and fore-aft frequencies. For the blades, the edge and flap frequencies were provided. Based on this, it must be analysed and compare those frequencies with the rotor speed (P), the 3P and the 6P component. It is desirable to design an operating strategy that avoids operating at multiples of the structural frequencies, as they are critical points of operation where the mechanical loads increase and the lifetime of the turbine can be reduced due to fatigue loads. Besides, the strategy must ensure a smooth switching at the first and second constant speeds with the operating curve. This has been achieved by setting both constant speed lines with a minimum length, in such way that the controller of the turbine is switching the to different operation modes excessively, as this could reduce the efficiency of the machine. Another important aspect to look at when designing the operating strategy, is to ensure that the wind turbine operation is not close to the stall front. The stall front curve is the curve that connects the maximum point of the constant wind speed curves. It determines the beginning of the stall region where the blades will be exposed to high loads and the power extraction will not operate efficiently. Based on the above, the design of the operating strategy was carried out. The first constant wind speed was set at 1.2 rad/s, avoiding a 6P frequency in the blades (flap natural frequency) that would appear at approximately 1 rad/s. As the design of the operating strategy must be a trade-off between energy capture and reduction of loads, it was decided the above as the best option for this machine. Rotor speed (rad/s) Generator torque (Nm) Aerodynamic Torque (Nm) Fist constant speed region (end) T0 1.2 1432.923 163076 Second constant speed region (beginning) T1 2.02 4640.24 462004 Rated torque 2.02 10137 853106 Table 2.0 generator torque at constant speed switching point The beginning of the second constant speed region is determined by the maximum generator speed which has been set at 170 rad/s (2.02 rad/s at the rotor side). It can be seen in Figure 2.0 the operating strategy curve of the machine, where it can be appraised that the operating strategy has avoided the 6P natural frequency stated above. The stall region is far enough from the operating region of the machine, ensuring a good performance and better efficiency. Figure 2.0 Aerodynamic torque-rotor speed diagram. Operating strategy curve of the wind turbine 2.3 Discussion of results In general terms, the design of the machine has been successfully carried out, as it can be seen in Figure 2.0, covering the following critical aspects of any operating strategy of a wind turbine: After carefully analysed the natural frequencies and compared with the 3P and 6P resonance frequencies, it has been set the cut-in speed of the machine at 1.2 rad/s. Also, this strategy will ensure that the damping losses in the machine do not have excessive effect on the power generated, as at very low rotor speeds the losses can overcome the power generated. The operating strategy ensures that the turbine will operate between the desired wind speed range. In this report, it has been set the wind speed range between 4m/s and 25m/s. It has been secured a smooth switching transient between the two constant speed regions and the maximum power tracking curve by establishing a reasonable size of the constant speed regions. It could be arguable whether this operating strategy is the most efficient or there are better options that would adapt to this wind turbine. The truth is that there are multiple options and different strategy plans depending on the preferences of the design. In this report, the aim has been to find a trade-off between load reduction and efficient power capture. 3.1 Baseline and procedure In order to achieve an efficient operation of the wind turbine, the control must play an important role in the operating strategy. An appropriate wind controller design will allow for a better wind energy capture as well as the mitigation of fatigue loads, as they considerably reduce the lifetime of the machine. Hence, the control task of a wind turbine is to maintain the appropriate operational state as the wind speed condition change, as well as enhancing its dynamic properties. In this report, the main goal is to design the operational controller, which is divided in two different regions, below rated and above rated power. At below rate conditions, the aim is to extract as much power from the wind as possible. This will be achieved by varying the reaction torque by measure the rotor speed or the output power. The second task of the controller is to ensure a smooth transition between the 1st constant speed region and the maximum power tracking curve. At above rated operation, the performance of the turbine will be carried out by pitching the blades. By doing so, it will allow the turbine to maintain the generation at the rated power value, take action to alleviate the increased loads at different parts of the wind turbine and to keep the desired stability margins of operation. For the above rated controller, it will be used a PI pitch controller along with an extra pole and zero and the set gain of the transfer function, resulting the transfer function as following: The nonlinearity nature of the wind turbine operation leads to a nonlinear control design. The gain scheduling is the most used control technique to accommodate the nonlinearities [3]. The performance of this technique is to continuously change the structure of the controller according to the local set points, such as aerodynamic torque, rotor speed and pitch angle. For instance, as the torque sensitivity varies nearly linear with pitch angle, it can be compensated by varying the overall gain of the controller linearly with pitch angle. As the design of the above rated controller is normally more tedious, it will be first designed the above rated controller and then, by varying the gain, redesign the below rated controller. Besides, when designing the controller of variable speed pitch regulated wind turbine, it must be paid special attention to the damage caused by the vibrations on the drive train, as it produces serious risks of failure. It has been noted that for the case of the wind turbine in this that the first drive train mode need to be actively damped, in order to alleviate the large torque transients at 13 rad/s. To obtain the transfer function of the drive train filter, it will be the general form of a band pass filter: The block diagram with the filter integrated can be seen in Figure 3.0. The design of the filter will be designed such that the filter feeds back only the oscillations at the resonant frequency. Figure 3.0 Plant with the drive train filter implemented As the drive train filter is located at the feedback loop, the equivalent transfer function of the plant and the filter will be given by the following equation: 3.2 Drive-Train Filter and Controller Design Drive Train Filter Design In order to damp to suppress the peak at the first drive train mode, it has been designed the transfer function of the filter. To do so, three parameters have been set in the transfer function. The gain (k), the frequency at which it is aimed to amplify in the feedback loop () and a scaling factor (n), which is used to set the frequency of the poles in the transfer function. After a trial and error procedure in MATLAB, the transfer function designed is the following: In Figure 3.1 is shown the Bode diagram of the system with and without drive train filter. It can be appraised that the peak in the drive train mode has been successfully damped, reducing the mechanical loads in the machine and hence, improving the lifetime of the turbine. Figure 3.1 Bode plot with the effect of the drive train filter in the system Controller Design for Above and Below Rated operation To control rotor speed and torque it is necessary to use pitch of the blades at above rated wind speeds. It has been designed a complete controller for the turbine for smooth switching between different operating modes. Apart from the pitch-PI controller, the gain scheduling technique has been applied to the design for the non-linear design section. The controller must assure a gain and phase margins above certain levels (4 dB and 30 degrees respectively) when checking the stability using the open loop functions, providing stability for the closed loop system. The aim is to provide good disturbance rejection at low frequencies, the required bandwidth at 1 rad/s, and good high frequency roll-off. With these main objectives, the transfer function designed for the given wind turbine is the following: It is shown in Figure 3.2 the Bode diagram of the controller, where it can be appraised the effects that the poles, zero and gain have on the systems. The proportional gain of the transfer function sets the initial gain value (20 log10 (|k|) and remains constant with the frequency. The proportional gain does not contribute to the phase of the transfer function.   Ãƒâ€šÃ‚   Figure 3.2 Bode diagram Above Rated Controller The pure integrator , produces constant gain contribution of -20 dB/dec from an infinite frequency. It also produces a constant phase of -90 degrees. The pole in the transfer function contributes to the gain with a negative 20dB/dec slope at its frequency of operation (1.95 rad/s). With respect to the phase, it contributes with a -45 deg/dec between a decade after and a decade before its frequency. That is, for a frequency of 1.95 rad/s, it starts to contribute at 0.195 rad/s and will end at 19.5 rad/s. The zero in the transfer function contributes to the gain with a positive 20 dB/dec slope and with a positive 45 deg/dec slope for the phase. Analogous to the pole, the phase contribution starts and ends one decade before and after the frequency of the zero. Knowing the above concepts and after a trial and error procedure, the gain scheduling technique was implemented and the design of the controller has been successfully completed. It can be seen in Figure 3.3 and 3.4 the differences between the effect of gain scheduling. It has been designed the controller for the plant dynamics at speeds of 12m/s,15m/s and 25m/s and applies for the same system with and without gain scheduling. Figure 3.3 Bode diagram of the plant without gain scheduling Figure 3.4 Bode diagram of the plant with gain scheduling It can be appraised that the system with the effect of the gain scheduling becomes stable, while without the gain scheduling system the gain and phase margins do not meet the requirements stated above for a feasible strategy. The design of the controller gives a positive gain and phase margin to the system at 1rad/s, ensuring the rejection of disturbances above these frequencies [4]. Once the above rated controller is designed, it has been carried out the design for the above rated operation. It has been tested for below rated wind speeds of 4m/s and 10m/s (resulting roughly the same response) and as it can be seen in Figure 3.5, the system has been successfully integrated as the phase and gain margin meet the specified requirements. As part of the gain scheduling implementation, the transfer function of the controller for below rated condition will just adjust the gain of the transfer function. After a trial and error procedure the transfer function obtained is given by the following equation. Figure 3.5 Bode diagram of below rated operation (with drive train filter) Note that for the below rated system analysis, there must be included the drive train filter at the feedback loop. 3.3 Discussion of results Based on the results, the design of the controller by applying gain scheduling technique has been successfully completed. As in any controller design, it must be aimed for good stability margin, both phase and margin, otherwise the system could destabilize and therefore cause high load fluctuations. Both below and above rated controller have been designed accordingly to these requirements and the phase and gain margin meet the minimum stablished (4dB for gain margin and 30 degrees for phase margin). 3.4 Effect of wind turbine size in the controller design. An important aspect of the controller design of a wind turbine is the size of the aforementioned. The wind turbine industry is going towards an increasingly bigger size of the turbines, which brings out new challenges when it comes to the design of the controller of the machine. As the rotor is continuously interacting with a very complex wind field, the prediction of the behaviour of the machine will become more difficult with an increase in size. In other words, as the size of the machine increases, it might be extremely difficult (when not impossible) to achieve the desired margins of stability, as the structural elements will become more flexible and dynamically more active. This does not necessarily mean that the system will become unstable with a bigger turbine, but proposes that controller need to be designed and tuned more carefully as the gain and phase margins will reduce. 4.1 Baseline and procedure As stated in section 3, the importance of the controller remains at the stability of the system. A system with low crossover frequency will present more fluctuations and a poor stability in terms of power generation, rotational speed or generator torque. The aim of this section is to give a better understanding of the design of a system with acceptable crossover frequency and also the importance of the drive train filter design, which as it was shown in the previous section, will help to damp the first drive train mode and therefore considerably reduce the mechanical loads. The will be compared for variables of the wind turbine for both above and below rated operation. The first tasks have been the comparison between the system with good crossover frequency and the system with no drive train filter. In order to do so, it has been compared the power output of the machine, the generator speed, generator torque and the pitch angle. For simplicity on the interpretation of the results, it will be compared the simulations at 15m/s of wind speed (above rated operation), and 9m/s of wind speed (below rated operation). For each wind speed, different turbulence of the wind field has been analysed. The second tasks have consisted on the comparison between a system with a good cross over frequency and a reduced cross over frequency. Again, to give the reader an easier understanding of the simulations, it will be compared the different systems at a wind speed of 15m/s. 4.2 Investigation of the controller performance Comparison between the good cross over frequency and no drive train filter systems It can be appraised in Figure 4.0, the power output of the turbine for wind speeds of 15 m/s and 9m/s. It is immediately apparent that for each speed, the higher the fluctuation, the higher the disturbance and therefore the less efficient energy production of the turbine. The mean production for 15m/s and higher disturbance accounts for 4.83MW and for 9 m/s is 2.8 MW. Compared with the wind field with small disturbance, the differences are not very noticeable, as the production accounts for approximately 4.7MW and 2.4 MW respectively. With respect to the comparison between the different systems, the figures show negligible differences between the system response at different disturbances. This is because both systems have a crossover frequency of 1 rad/s. Besides the reason why the system with no drive train filter seems to have no effect on the system is because as stated in section 3, the aim of the filter is to damp the drive train mode at a certain frequency. As it is being plotted the response over time, the slightly differences at the frequency of damping cannot be appraised in these figures. Figure 4.0 Power output of the turbine for 15m/s and 9m/s In terms of the generator speed (Figure 4.1), the same pattern than in the power output has been acknowledge. The higher the turbulence intensity in the wind, the more difficult the control of the generator speed, and therefore the higher the fluctuations. In terms of mean values, the 15 m/s wind speed produces a mean generator speed of approximately 120 rad/s for a high turbulence intensity, and 111 rad/s at 9m/s of wind speed. Figure 4.1 Generator speed of the turbine for 15m/s and 9m/s Talking about the generator torque, it presents the same patterns than the previous simulation, as it can be seen in Figure 4.2, where there are no apparent differences between the two systems, and the turbulence intensity influence the variation of generator torque. The mean values for the higher turbulence intensity are 26.2KNm and 42.4KNm for 9m/s and 15m/s respectively. For the lower fluctuation of wind, the mean values of torque account for 22.7KNm and 42.7KNm. Figure 4.2 Generator torque of the turbine for 15m/s and 9m/s As a final analysis, it has been plotted the pitch angle for the different system at different speeds. It can be appraised in Figure 4.3 that the pitching of the blades does not perform at 9m/s, except when the turbulence intensity is significantly high, in which case it might overpass the above rated wind speed and therefore the pitching start to act. By contrast, for the 15m/s simulation speed, the pitching angle varies constantly trying to absorb energy from the wind more efficiently. Figure 4.3 Pitch angle of the turbine for 15m/s and 9m/s Comparison between reduced and good crossover frequency It has been simulated the response of the two system with good and reduced crossover frequency. The good crossover system has a crossover frequency of 1 rad/s while the reduced crossover system is 0.5 rad/s. The results are shown in Figure 4.4 and 4.5, where some differences can be noticed. The reduced crossover frequency system has a more unstable generation of power for both turbulence intensity scenarios. As stated in Section 3, the system with a reduced crossover frequency will have a poorer performance under disturbances and will reject those more inefficiently than the one with a good cross over frequency. Figure 4.4 Power output and generator speed of the turbine for 15m/s and 9m/s Figure 4.5 Generator torque and pitch angle of the turbine for 15m/s and 9m/s Having designed and analysed the different aspect of a wind turbine controller, it can be concluded that the design has been carried out successfully, ensuring a stable performance of the system with an efficient mitigation of loads. It can be argued whether the design of both operating strategy and controller are the best option in terms of performance, but the main objective of this report is to give an understanding of the performance of the machine and the control system operation, as well as to understand the new challenges that the increasingly size of the wind turbines might bring to the design of the control strategy. [1] E. A. Bossanyi, The Design of Closed Loop Controllers for Wind Turbines, Wind Energy, vol. 3, pp. 149-163, 2000. [2] T. Burton, Cp-lamda performance, Chichester, Willey, 2011, pp. 173-174. [3] A. P. Chatzopoulos, Full Envelope Wind Turbine Controller Design for Power Regulation and Tower Load Reduction, University of Strathclyde, Glasgow, 2014. [4] H. D. B. A. R. J. M. Fernando D. Bianchi, Control of Variable-Speed Variable-pitch Wind turbines Using Gain Scheduling Techniques, in Wind turbine control systems, London, Springer, 2007.

Health Care Communication

University of Phoenix Material Health Care Communication Methods The following assignment options provide the opportunity for you to explore communication methods for different kinds of health care scenarios. The assignment options also allow you to examine the effects of HIPAA and other regulations on health care communication. Select and complete one of the following assignments: Option 1: Nursing Home Administrator Option 2: Communications Coordinator Option 1: Nursing Home AdministratorRead the following scenario: * As the administrator of a local nursing home, you have just received notification that the organization is being purchased by a national group. Because of new policies to be implemented, many of the residents will be displaced. To make the situation more challenging, some of these residents have difficulty communicating, have no local family, and have not indicated that they approve the release of their medical information. Arrangements must be made for these individu als.Write a 1,050- to 1,400-word paper on the different types of communication methods for the health care organization described in the scenario. Include the following in your paper: The advantages and disadvantages of using traditional, electronic, and social media for health care communication The effects of HIPAA and other regulations on the use of these media for health care communication Cite a minimum of two sources, one from the University Library and the other from the course textbooks or Electronic Reserve Readings, to support your position.Format your paper consistent with APA guidelines. Option 2: Communications Coordinator Consider the following scenario: * You are the communications coordinator for a national drug manufacturer. Recently, there have been reports of significant negative effects caused by one of your medications that is used by a significant population. News reports have alleged that one of the individuals affected is a well-known public figure. You are t asked with addressing the news reports and the general public regarding this situation.Write a 1,050- to 1,400-word paper on different types of communication methods for the health care organization described in the scenario. Include the following in your paper: The advantages and disadvantages of using traditional, electronic, and social media for health care communication The effects of HIPAA and other regulations on the use of these media for health care communication Cite a minimum of two sources, one from the University Library and the other from the course textbooks or Electronic Reserve Readings, to support your position. Format your paper consistent with APA guidelines. Health Care Communication The patient who is distrusting of their nurse will not be compliant or may not take part in self-care. Nurses communicate each day with patients and coworkers. Building effective communication skills in the healthcare industry can lead to optimal outcomes. The first step to communication is to determine what the message to be conveyed is and put it in a logical order. Make the message brief. Choosing your words correctly will allow the receiver to understand what you are saying. Be considerate of the patient's education, cultural, knowledge base and level of understanding.When you begin to speak be sure that you have the attention of the receiver, at the end of the conversation get feedback to ensure that your message was conveyed correctly. This paper will discuss the definition of health care communication, the relevancy of effective personal healthcare communication with other health care professionals and patients, relevancy of effective healthcare communication to health outcome s, and how the lack of effective personal and professional healthcare communications contributes to poor health outcomes. Healthcare communication can be defined as when an individual seeks information n health related issues.According to Healthy People 2010, (n. D. , overview), â€Å"Health communication encompasses the study and use of communication strategies to inform and influence individual and community decisions that enhance health. â€Å"The dissemination of information can be done via public communication or in an organizational context. Public communication refers to, â€Å"presentations, speeches, and public addresses made by individuals on health-related topics†. (Morehouse, 1998, p. 4). Health communication in the organizational context refers to how administration or staff provides information in regard to healthcare.The use of communication for healthcare issues is important to many people in that it increases awareness of healthcare risks, benefits, availab ility and support systems. Public communication utilizes pamphlets, public service announcements, etc. , to alert persons to health issues which can â€Å"encourage healthy behaviors, create awareness, change attitudes, and motivate individuals to adopt recommended behaviors. â€Å"(Healthy people 2010, n. D. , overview). When communicating with patients the nurse needs to look at the overall picture of the patient. This is his or her values, beliefs, culture and knows the health literacy of the attain.The degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions. When a patient understands his or her disease process it helps that individual make the right decisions regarding their healthcare. A nurse who is able to understand a patient's values, culture, beliefs, and incorporate them into the patients care builds a sense of trust between the patient and nurse. Communicating wi th other healthcare professionals also requires effective healthcare communication.Some nurses may not know their role responsibilities. As a charge nurse on the floor you can explain to that nurse what her role is. The charge nurse will need to be accurate in the information she provides, consistent, reliable in that the content is correct and up to date. When positive, caring relationships establish between patients and caregiver, patients report a greater ability to cope effectively with their illness and greater compliance with health care regiments. â€Å"(Morehouse &Northouse, 1998, up. 79-80). Patients fear the unknown.Being in a hospital can be scary if they do not know what is happening to them. A nurse who speaks to a patient regarding his plan of care and shows empathy will give that patient a sense that he or she cares. A patient who understands his disease process will be able to make sound decisions, discuss treatment with family and cope with the situation. According to Williwaw, (2007), â€Å"There are five elements in the process of communication; the sender, the receiver, the message, the medium and internal and external static. â€Å"A problem with any of these elements can distort the meaning of what is trying to be conveyed.