Maria Luisa Bemberg free essay sample

A discussion of the works of Maria Luisa Bemberg, a famous Latin American filmmaker. This paper looks at the work of Maria Luisa Bemberg, a Latin American filmmaker that is considered to be one of the best directors known. The author discusses Bembergs famous works, such as the popular love story Camila and examines the type of themes that she focuses on. Maria Luisa Bemberg started making film after she had children until they grown and they had theirs. Most of Maria Luisa quality films were matchless in Latin America. Her first feature when she was only sixteen years old was in 1981 with Momentos/Moments. Her second contemporary work done by Bemberg was Senora de nadie/ Nobodies wife (1982). Because her earliest films were short documentaries and her first feature were contemporary domestic dramas people were surprised at Bembergs choice of Camila and three other period pieces. The popular love story Camila (1984), a theatrical style work of Miss Mary (1986), a post-colonial tragedy, Yo, la peor de todas/ I, the worst of it all (1990), finally a film about personal struggles and silencing one of Latin Americans famous female in a movie called, De eso no se habla/ I dont Want to Talk about It. We will write a custom essay sample on Maria Luisa Bemberg or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page

Homework Essays - Electronic Cigarettes, Smoking Cessation, Smoking

Homework Essays - Electronic Cigarettes, Smoking Cessation, Smoking Homework: The following is a list of arguments that lack a they sayany sense of who needs to hear these claims, who might think otherwise. Like the speaker in the cartoon who declares the Sopranos presents complex characters, these one sided arguments fail to explain what view they are responding towhat view, in effect, they are trying to correct, add to, qualify, complicate, and so forth. Your job in this exercise is to provide each argument with such a counterview. Feel free to use any of the templates that were provided to you. a.Our experiments suggest that there are dangerous levels of chemical X in the Ohio groundwater. b.Money and material forces drive history. c.Proponents of e-cigarettes question the smoking ban. d.Male students often dominate class discussions. e.The film is about the problems of romantic relationships. f.Im afraid that templates like the ones in the book will stifle my creativity. Homework: The following is a list of arguments that lack a they sayany sense of who needs to hear these claims, who might think otherwise. Like the speaker in the cartoon who declares the Sopranos presents complex characters, these one sided arguments fail to explain what view they are responding towhat view, in effect, they are trying to correct, add to, qualify, complicate, and so forth. Your job in this exercise is to provide each argument with such a counterview. Feel free to use any of the templates that were provided to you. a.Our experiments suggest that there are dangerous levels of chemical X in the Ohio groundwater. b.Money and material forces drive history. c.Proponents of e-cigarettes question the smoking ban. d.Male students often dominate class discussions. e.The film is about the problems of romantic relationships. f.Im afraid that templates like the ones in the book will stifle my creativity.

Argumentive Essays - Trojans, Mythological Kings, Epic Cycle

The Trojan War I am almost sure that we all know the stories of Greek Mythology. Now for Troy and its war, we may only know the stories implied by novels and movies. Some tails and myths have only part of the story which might seem more exciting then what actually started the fight, and how it really ended. Achilles didn?t really die at the end of the war. He was said to conquer Troy after the war had ended. This war is very popular because it lasted a decade. Achilles was the son of Thetis and Peleus. His mother tried to protect him from a prophecy of early death by dipping him into the River Styx, which would make him invulnerable? However, she held him by the heel so his heel was unprotected. She sent him to hide in the court of the king of Scyros, where he was disguised as a girl and married the princess Deidamia. Odysseus disguised himself as a traveling merchant, and tempted Achilles into revealing himself using a beautiful sword. The Iliad is a story that deals with a small part of the Trojan War. The cause of this war is when Paris, the prince of Troy, sailed to Sparta, seduced and abducted Helen and returned to Troy. When Menelaos discovered that his wife was gone, he gathered a number of Greek generals together to go with him, conquer Troy, and retrieve his wife. However, the Iliad only covers a few months during the tenth year of the war. In this time, many important events took place that could have possibly altered the outcome of this historic event? Two beautiful women whom were enemies of the Achaeans are captured during one of the many raids the army had on Troy. One of the women, named Chrysies is the prize for Ahomemnon (the king and commander-in ?chief of the Achaeans). But Chrysies? father, Chrysies wants his daughter back. Cheresies, whom was the priest God of Apollo, is hoping to go to the Achaean camp and claim his daughter. Unfortunately, this plan did not work out. And because of this, Chrys ies prays to Apollo for help. Apollo did in fact help the old man by spreading a deadly plague through the Achaean army, killing hundreds of them. After days of this, the Achaean?s most honored soldier, Achilles calls a meeting to determine the cause of the plague. A soothsayer of the Achaeans determines that King Agamemnon?s arrogance caused the plague by not returning the woman whom was captured to be his war prize. After finding this out, the woman is returned but Agamemnon takes Briseis whom was the prize captured for Achilles. Achilles is angry and publicly insulted so therefore he refuses to fight for the Achaeans and withdrawals his troops. He then requests to his mother Thetis (a sea nymph) to influence Zeus to help the Trojans defeat the Achaeans. The leader of the Gods promises Thetis that he will help. Zeus sends a dream to Agamemnon that has him convinced he will defeat the Trojans in battle the next day. With the order from Agamemnon, the army prepares itself for attack . The Trojans and Achaeans draw towards each other and Paris challenges one of the Achaeans to a one on one fight. The challenger of this is Menelaos. The winner will win Helen and both sides will agree on a treaty of peace. During the duel, Menelaos wounds Paris and begins dragging him to the Achaean?s territory when suddenly, Aphrodite appears and rescues him. Agamemnon announces to his army that they have won and demands that Helen is given back to them. Goddesses Hera and Athena want a complete destruction of Troy and they ask Zeus if no truce were made. Zeus in turn gives in and grants them their wish. As a result, the fighting soon resumes. As a way to start the war anew, Athena searches for Pandaros, a Trojan leader and tells him to kill Menelaos. Being the type of person Pandaros is he follows through with her advice. But instead of killing Menelaos, he only wounds him. The Achaeans are shocked that the Trojans would do this being that the truce is

Signs and Miracles Research Paper Example | Topics and Well Written Essays - 1250 words

Signs and Miracles - Research Paper Example The miracles of Jesus create a representation of his state as the Messiah and close reading with the stories of the miracles, along with an understanding of the past and the future allow the reader to see the miracles than more than just wondrous events. The Eight Miracles During his lifetime Jesus performed a long series of miracles that helped to give credibility to his ministry. In addition, these miracles gave beauty and compassion to the historic value of the nature of his love. His miracles can be broken down into six periods and the stories of those miracles provide different meanings to the context in which they are told. The first period is a â€Å"preparatory period† between his baptism until he calls his disciples to him.1 Four miracles occurred during this time that as it is reported in the histories. He then continued forward to perform sixteen miracles in the first portion of his ministry, eight in the second, six in the third, and four in the last days before hi s death. After his resurrection he performed one miracle. The total number of miracles reported as having been done by Jesus is 34.2 There can be identified eight miracles that are considered to be sign miracles. Leeler, Grimbly, and Wiggins define seven sign miracles that suggest that Jesus is the son of God. These ‘signs’ are intended to signal his arrival and to be taken as reflective of the nature of worship that would be used towards Jesus as the son of God. As well they define him as deified. The first sign, according to Leeler, Grumbly, and Wiggins, is the most important sign as it is the first to signal that he was more than a prophet or a man. The first sign miracle identified is that of the miracle at the wedding feast in Cana where Jesus turned the water into wine.3 The importance of these signs, such as turning the water into wine, is that they are visible and do not leave an abstracted idea of the nature of Jesus. They clearly proclaim that he is divine.4 I n turning the water into wine, the act provided for â€Å"symbolic actions (that) were valuable for his purpose because they were able to integrate several levels of meaning into a coherent whole†.5 Jesus showed himself through compassionate and real life applications of his miracles. The sign of the wine is also connected to prophesy concerning the messiah. According to Koestner, the use of wine was symbolic of the expectation that there would be an â€Å"outpouring of divine favor upon Israel†, the quote from reflections that suggested that â€Å"the mountains shall drip sweet wine, and all the hills shall flow with it’ and sometimes connecting abundant wine with the restoration of Davidic rule (Amos 9:11, 13; Joel 3:18; Isa 25:6)†.6 That the messiah was from the line of Davis was an important proof of his deity, however reinforcing that deification through associating his miracles with wine provided for symbolic proof, as well the proof of his lineage. Because of the well known, but sometimes vague nature of prophesy, creating symbolic proofs was as important as creating blatant proofs. Short of crying out this claim, the miracle of creating wine from water was a sign to those who had studied the prophesies that Jesus was the Messiah that Israel had been waiting to arrive. The second sign miracle can be considered as the act of healing the royal official’s son. According to Gross who paraphrases John 4: 46-54, Jesus says to the official that â€Å"

Errors in crime scene investigating Research Paper

Errors in crime scene investigating - Research Paper Example The court also must make sure that no innocent person is ever wrongly punished or convicted for offences that he or she has not committed. In the modern day, with the advent of technology and the availability of modern forensic test facilities, crime scene investigation (CSI) has acquired much significance in the process of police investigations and the conducting of trials. During 1998, the US Department of Justice, in what could be termed as a landmark study, has unearthed 28 cases of â€Å"wrongful convictions† by means of DNA tests and thus brought to the fore the â€Å"fallibility† of the law enforcement system (Doyle, 2010, 110). In most cases, the jury has relied on eyewitness accounts, which is the â€Å"oldest form of evidence† to pass their verdicts and 24 out of the 28 cases have entailed wrongful conviction due to â€Å"misidentification† (110). This adequately underlines the significance of scientific methods of investigation in determining th e complicity of offenders in the crimes they are accused of and to minimize errors in crime scene investigations. Thus, it transpires that in the interests of imparting criminal justice and to rule out errors in crime scene investigations the law enforcement system needs to deploy advanced technology. ... ost transparent and judicious manner is to facilitate the availability of forensic evidences that can irrefutably link the perpetrator to the crime under investigation. Criminals, invariably in all cases, no matter how meticulous and calculating they are, leave imprints of indelible evidence on the crime scene. While an efficient investigator, with the aid of modern technology will be able to unearth such evidences that can positively identify the perpetrator of crimes and help in proving his or her involvement in the commission or abetting of the crime. An investigation of the crime scene commences with the arrival of the first respondents at the location. Such persons may not necessarily be trained in forensics and hence they need to appreciate the significance of physical evidences that play a â€Å"pivotal and especially valuable role† and are the most â€Å"reliable† evidence (Crime Scene and Physical Evidence, 2009, p.4). Besides, they also must understand the imp ortance of proper custody and handing over of such evidences to the investigation team once they arrive on the scene. This way, the sanctity of the evidence they collect from the scene can be sustained and any possible errors can be ruled out. Crime scene investigation can be understood as a â€Å"process† that seeks to record the scene as it is and to recognize and collect any physical evidences that are â€Å"potentially relevant† to the crime (p.4). The process also envisages adherence to any â€Å"local laws, rules and regulations† that relate to CSI and forensic investigations and ethical as well as human dignity considerations (p.4). Similarly, removing unnecessary items, taking photographs and developing a â€Å"descriptive documentation† of crime scene are significant in the process of CSI (Death

District Sales Manager Essay Example for Free

District Sales Manager Essay The principle error Maureen made was underestimating how significant company culture could impact decision-making at every responsibility level. Even though Quaker had strict functional reporting lines, the organization supported an informal culture based on friendliness and openness. Most importantly, Quaker’s ethos required a high degree of influence by persuasion and charisma—not formal authority. Secondly, the communication vehicle that Maureen chose to carry and deliver her proposed plan was ill suited for interconnecting the plan and expectations. Instead of going with the organization’s pattern of utilizing personal relationships, teamwork, and the openness to express opinions and feedback, Maureen sent a memo directly to the titanium extrusion sales representatives. In the memo, she simply gave a rationale for making the change. In response, a District Sales Manager (DSM) called Maureen to ask for a more detailed explanation for the change due to its arbitrary nature. Therefore, Maureen presented her findings to the DSMs in a yearly sales meeting in the presence of the VP of Marketing. †¢Lack of empowerment from authority: Although Maureen’s plan obtained approval from her boss, Hugh Salk, there was never a statement from the VP of Sales to his subordinates (district sales managers and sales representatives) supporting the proposal. As seen in Exhibit 2, Lawrence Israel, the VP of Sales has direct power over DSMs. †¢Company’s hiring practices: Maureen was hired at a managerial position because she had a very attractive professional background that made her a highly desirable candidate for her role. However, this was not in line with the company culture that encouraged internal promotions rather than external hiring at a managerial level (‘Typically, managers who joined Quaker from other steel or metal producers found the company a confusing and frustrating place in which to work. For this and this other reasons, most of Quaker’s managerial positions were filled from within’, p2). †¢Ã¢â‚¬Å"Responsibility lines† structure: Due to the company’s growth, many managers and at times whole divisions were responsible to other departments even though there was not a preset hierarchy that linked them. This situation complicated to a certain extent the relationship between the product management groups and the sales force as can be inferred from the fact that the titanium DSM in Chicago had to report to two bosses (p5). †¢Sales force’s lack of adaptation: Sales representatives were assigned to accounts based on experience and usually had tough time cracking big accounts. This was in part due to lack of backing from the technical support services and sometimes from the RD labs as the larger accounts were more technically complex. It was also because there were no additional economical benefits to work on bigger accounts, thus harder work was not compensated in any manner (‘The Chicago DSM explained that a modest cash bonus existed, but that he did not use it, believing it had little effect’, p6). Hence, the only motivation for the sales people was closing a successful deal and working directly with customers which was frequent with small accounts. †¢Lack of relationship and communication: Maureen spent so much time analyzing the sales time simulations; therefore, she did not spend enough time getting to know other team members on the field. These circumstances did not favor building â€Å"trust† with the sales personnel and this lack of participation within the decision-making process hindered effective results (‘In response to the memo, one of the titanium DSMs called her to say that he had received several complaints from his salespeople about its arbitrary nature’, p8).

Fashion In The 20th Century Essay -- History Clothing Style Fashion Es

Fashion In The 20th Century Fashion is said to be evolutionary and not revolutionary. This was not true in the 20th century. Fashion revolutionized America and the rest of the world during this time period. Also, during this time period fashion evolved tremendously. New fabrics and innovations were introduced to America. When World War I came about, people had to sacrifice their clothing for the men at war and they dressed more conservative. Christian Dior changed all of that when he came out with the â€Å"New Look.† This look consisted of draped gowns with a lot of fabric being used. What Christian Dior was basically saying was that we should not have to sacrifice how we dress. In the 20th century, new synthetic fibers were invented, making new fabrics come to life like rayon and polyester. New technology changed many different ways we made our garments toward printing and construction. Of course the 20th century started out in the 1900’s. The silhouette of the female was made up of the pigeon-breasted bosom, tiny corseted waist, and full, swayback hips. There were many common designs in this era. One was a white, high-necked, trimmed cotton blouse with a heavier, dark shirt. Another was tailor-made jackets and skirts for working women. Most of the fabrics available were mostly natural fibers like cotton, silk, linen, and wool. Daywear was most often in shades of white, brown, and black, commonly in a small figured or floral print. Eveningwear consisted of lightweight silks in sometimes brighter solids or light-colored hazy prints. In this particular period, fancy trim meant status. Trim was very excessive as possible on shoulders, waist, and the lower half of the skirt. Items used included were lace, embroidery, jet beading, flowers, ribbon, and net. All of the hemlines reached the floor. Sergers were first introduced in this era. In 1910, most of the influence for fashion came from designer Paul Poiret and Eastern influence. Daywear silhouette included a head-to-ankle coverage with lowered necklines for the first time ever in decades. The primary silhouette was a straight, squarish outline with low hips. Common designs were long, ethnic influenced tunics with a skirt and waist sash, and horizontal layered appearance in skirt or vertical wrap effect on tailored jacket-and-skirt sets and dresses. Rayon was invented and used. Also used wer... ...isure to eveningwear, but natural fibers were still used with the organic flower child look. Loud and clashing colors were now in everyday fashion prints, from conservative to wild. Swirling psychedelic prints, dotted with flowers, medallions, and geometric shapes were popular. There was widespread use of designer names and labels as an incentive to shoppers, marketing everything from clothing to luggage with designers such as Geoffrey Beene and Christian Dior. No matter what decade or century you are in, fashion is going to change. People make fashion change and evolve through the decades with different events that happen. Early on, it was the designers who decided what men and women wore. Through the decades it became evident that we should choose and decide what we should wear to incorporate our environment. Women basically decided that they were the rulers of fashion and that they make fashion what it is today. Why shouldn’t they choose? Of course fashion is here to stay, so, I wonder what we would be wearing in the 22nd century? Sources Cited: Vintage Vixen Clothing Co. Fashion History. 1997-2005. Vintage Vixen. 20 Apr. 2005. http://www.vintagevixen.com/history

Mass and Chemical Reactions Lab Essay

Relationships in a Chemical Reaction Lab Introduction: This lab focused on mass relationships within a chemical reaction. To understand this lab first, it is necessary to understand the reaction that is going on in the reaction. The Copper (II) chloride hydrate reacts with Aluminum to produce Aluminum chloride, copper, and water. Theoretical yield and various other forms of yield must be understood too, theoretical yield is what amount of the product you should get theoretically according to your calculations; experimental yield is the product you get after you finish the experiment. Because of error usually your experimental yield will be off from your theoretical yield. Percent yield is the efficiency of the reaction to get to the theoretical yield. Data Collection And Processing: Raw Data: Table #1 : Substance / Object and Mass Table Substance / Object| Mass (Â ± 0. 01 g)| 200mL beaker| 67. 38 Â ± 0. 01 g| 200mL beaker + Copper| 69. 39 Â ± 0. 01 g| Copper| 2. 01 Â ± 0. 01 g| 200mL beaker + Dried Copper| 68. 01 Â ± 0. 01 g| Dried Copper| 0. 63 Â ± 0. 01 g| Qualitative Data: Before the reaction, the Copper (II) Chloride hydrate is a blue crystallized substance, the Aluminum was shiny and made crinkly sounds, it has a smooth metallic feel to it. During the reaction initially when stirred the water the water turns blue. When the aluminum is placed into the hydrous CuCl? the water becomes a darker murky substance. Steam is coming out of the water and aluminum is visibly dissolving. The aluminum is also turning black and vapor is forming along the sides. Foam like red pieces are forming and dropping. As the solid turns completely red the liquid is becoming clear again and is colorless.

Computerized Enrollment System Essay

Today, the progress of institutions is largely determined by the ability to make use of computer technology. Computerization is a conclusive evidence of the advancement in science and technology which task is to maximize its purpose, primarily in education. The converting of manual to automated system is one best alternative to carry out manually workloads such as keeping records, computations, and retrieving information in the shortest possible. In the global village of the new economy, larger automation companies have little option- they must find more ways and means to expand worldwide. To do this they need to minimize domination of the central corporate culture, and maximize responsiveness to local customer needs. And thus, utilizing a computerized system can be simple change like providing production workers for greater freedom of movement in performing their task (http:/www.automationworld.com.auto.thml). In Bataan Polytechnic State College, the college-wide computerized enrollment system was implemented. Last October 2005, they put into operation the college –wide enrollment system for the first semester of the academic year 2005-2006. Applying the results and data generated by the administration, the college was able to remedy usual problems during admissions and enrollments such as the tendency to overlook procedures, confusion among the students on proper enrollment steps, and the inconsistency of the information generated and submitted to various offices within and outside the BPST. Furthermore, the college was able to triple the number of students served each day during the enrollment period. This made the operation faster, more accurate and efficient. (http://www.bpsc.edu.ph/news2.html). Tagum Doctors College (TDC) of Tagum City a private institution of learning is dedicated to the quality of education of the youth to preserve and enrich the life of all Filipino heritages. Its current enrollment process is totally paper-based. Their enrollment process was the result of disconnected accounting, cashiering, and student records systems.  This led to staff manually calculating individual fees. Additionally, the staff could not accommodate the expanding student population. Faced with these manual, disconnected processes, Tagum Doctors College wanted to simplify student enrolment with a self-service system that automatically generated payment amounts by centralizing all student, course, and accounting details. In this connection, the researchers intend to unload their agonies by creating a computerized enrollment system. Statements of the Problem After the preliminary investigation to the institution of Tagum Doctors College, the researchers encountered the following problems. 1. Difficulty in retrieving records of the students 2. Feasible errors in computing students’ accounts 3. Complexity in tracing the records of current enrolled students 4. Delayed in processing a report 5. Difficult to identify the rooms and teacher on its subject and 6. There is a conflict arise in making manual students class schedule. Objectives of the Study This study aimed to satisfy its main objective of developing an automated enrollment system that will support one of the operations of Tagum Doctors’ College. Along with this general objective, this also aimed to satisfy the following objectives: 1. To access easily in retrieving record of the students; 2. To establish errors free in computing Students Accounts; 3. To trace easily outline record of the currently enrolled students; 4. To automatically generate accurate reports; 5. To identify the room and teacher on its subject; 6. To lessen conflict that arises in making students class schedule; Scope and Limitation The researcher designed this study to the institution of Tagum Doctor’s College to serve the administration to have accurate processing during enrollment period. This study designed a client/server system that shall cover the process in the registrar’s office, Dean’s office and Cashier’s office. The System caters the following: a) The Student’s information must have encoded into the system to search easily, to give/provide a back-up files for the students. b) For the cashier, the system can compute the total assessment of the student including the miscellaneous fees etc. it also automatic deduct the payment of the student if they fully paid before the examination period and the remaining balance. c) The system can provide automatically a student class schedule. For the transferee and irregular student, the system can schedule their subjects. In addition, it can edit one-by-one the subject codes, time schedule if the student wants to change their schedule. d) Automatic generate the student’s number, receipt number and arrange the report what the user’s need. e) The system can also view the grades of the students. f) Can print out hard copy for the important means such as lists of students, subject codes, time schedule and the assigned teachers. Significance of the Study This proposed Computerized Enrollment System is relevant and beneficial to the college in away that the process in keeping data’s, cashiering and making reports becomes more consistent. In addition, it would be easier and would be lessen the workload of the involved offices. It would also help the school administration to manage and transact with other schools. The registrar’s office would handle the student assessment accurate. It also eases for the student’s transaction. Furthermore, the adoption of this system would provide data security which reliable on every transactions. The following persons can benefits this study: Cashier. These systems will the school cashier in computing the total  assessment of the students and other miscellaneous fees accurate and clear Dean. This system will help the Dean in keeping all the transactions regarding the student’s records, organized and manage all the transactions accurate and safety. Faculty. This system will help the faculty minimal their work load during enrollment period. It gives an easier way of identifying their assigned subject. Registrar. This system will help them in keeping the student’s records orderly and safely. School Administration. This system will help them to manage and organize the time schedule in handling the transaction. Student. This system will also help ease the students in updating their subjects available and other transactions easier and faster. It will also provide the students to view their grades. Review of Related Literature The Review of Related Literature represents the mention principles, ideas, concept, theories, facts and views regarding the relevant variables of aspects as gathered from different books scrutinized by the researchers and searched from the internet Today, the trend of technology speeding up very rapidly, automation was developing as a result advanced in the design of machine. Technology has affected society and its surroundings in a number of ways. In many societies, technology has helped develop more advanced economies including today’s global economy and has allowed the rise of a leisure class. Most early machine was design to operate under a specific set of condition, when this condition change manual adjustment was necessary to assure proper operation. This was not a major shortcoming, since the machines operated at relatively slow speeds. It was quickly recognized as valuable to assure efficiency and accuracy and manufacturing process. The term operation refers to a wide variety of system and processes that operate with little or no human intervention. In the most modern information system, control is exercise by the system itself through control devices that sense changes in such condition as temperature, rate of flow to make adjustment to compensate these changes. The development of digital computer, which can monitor external condition and make an appropriate adjustment to the system, added farther impetus to the application of automation. It trices to increase understanding of the ways  in which information is generated, stored made available, and used. In the practical sense it undertake specific action to try to improved the same function of information technology (Grolier Internal Encyclopedia Vol. 2, 1995) Automation plays an increasingly important role in the global economy and in daily experience. Engineers strive to combine automated devices with mathematical and organizational tools to create complex systems for a rapidly expanding range of applications and human activities. A computerized system will allow you to make better use of your time. Why spend time typing information into a document, when you could be hosting a job search workshop (www.truckwin32.com and www.Shippernet.com). The De la Salle University’s ITC Systems management Office designs, develops, implements and evaluates computer- based information systems as requested by the academic and administrative units to facilitate their operations. These information systems include their enrollment system, student’s information systems and accounting system for student’s assessments. The University desires to fully computerize its processes and integrated all its information systems that are evaluated annually. Its quality policy includes the list 99.9 percent availability of computing resources, at most customer satisfaction, prompt and positive response to customer’s requests, feedback on customer’s request (http:/www.disu.edu.ph/offices/itc/smo/default.asp). The Automated Enrollment System of Samar State University aims for an accurate, user friendly, efficient system that can help both the student and personnel for fast data processing of enrollment. Engr. Hediki Hashimoto, a Japanese volunteer headed the creation and conceptualization of the system. He was assisted by the information technology faculty from the College of Engineering and Arts and Sciences. The system, which is web, based, uses PHP programming language with data stored in MySQL is run through the intranet of SSU. A dry-run for this automated enrolment was done last summer and the first semester of this school year. Offices affected with the automation were the registrar, cashier, accounting, and the Colleges of Education, Engineering, Arts and Sciences, Industrial Technology, Nursing and Graduate Studies. Feedbacks from the students were formulated when the first semester started. Over 75 % of them says that the automation process of enrollment was better compared with the old system. With the good result of the dry-run  the automated enrolment system will be finally implemented this 2nd semester. Saint Louis University’s Computerized Program was envisioned by Father Ghesleen de Vos. He saw the importance of automating the academic systems particularly the accounting and registrar’s offices. His goal was to lessen the burden of handling tedious tasks that was brought about by the voluminous records processed every semester. In June 1969, Fr. De Vos’ vision became a reality with the acquisition of the IBM 1130 system. This gave birth the Saint Louis University International Business Machines Electronic Data Processing Office (http:/www.slu.edu.ph). Mapua Institute of Technology started its computerized operations in the collection of relevant student information in the 1960’s. During the 1997 University days of the Mapua Institute of Technology, the MIS office held a demonstration of a Windows-based prototype of an on-line enrollment system for the Deans and several Heads of Offices. The system, developed using Fox Pro for Windows, displayed various features for a faster enrolment. The first on-line enrollment system and student information system was developed and was tested on the summer of 1998 where all students gathered at the Burgos Gym for their enrollment (http:/do-it.mapua.edua.ph). Context Flow Diagram The Context Diagram also includes the people and other organizations which the system communicates. It also contains the data the system produces and the data that the system receives from the external entities. The entire system is placed on the process Recording and accessing, under which several processes make up the entire Computerized Enrollment System. Figure 1, are the external entities that send or receive information from the system are included in the Context Diagram. During enrollment, the students provide their necessary data for the system to process the transaction. The system activate by supplying the needed data that will comprise the student information, payment of enrollment fees and other charges. The student’s information given by the student to the Registrar’s Office that will be stored in the system. After the student paid his obligation and receive a receipt from the Cashier. The Registrar releases the class schedule of the students with the other student’s records to have a hard copy for them. The Dean will have the record of class list. Figure 1. The Context Flow Diagram of Computerized Enrollment System Definition of Terms The following term used in this study are defined conceptually for clarity and easy understanding of the concepts. Class list. The lists of the student every subject given by the Dean of College to the Faculties. Class Schedule. The form of the student with the room and time assignment, and total assessment of the student. Requesting Class list. The Dean’s has the authority to access on the system and to have a hard copy. Printed Student’s Record. The hardcopy records of the student kept by the Registrar. Printed Student’s Record. The hardcopy records of the student kept by the Registrar. Recording and Accessing. The automated system can kept the records, monitor, and compute the assessment of the student. Registration form. The form that need to filled up by the student to have a Student’s record to the Registrar’s Office. Student’s Accounts. The assessment of the student saved also on the system. Student ID number. This number assigned on the students to retrieve their profile and accounts. Student’s Record. The records of the student saved on the system.

Critical Study of the Development of a Vertical Axis Wind Turbine at Cliff Searle The WritePass Journal

Critical Study of the Development of a Vertical Axis Wind Turbine at Cliff Searle Abstract Critical Study of the Development of a Vertical Axis Wind Turbine at Cliff Searle AbstractProject IntroductionTypes of Wind TurbineWind Turbine Theory  Betz LimitCyclic LoadingReynolds NumberSolidityTip Speed ratioProject DefinitionProject AimsProject DeliverablesBackgroundLiterature ReviewDesign Concept GenerationAssessmentDesign ConceptDetailed DesignBlade DesignMaterial Selection and ManufactureCAD DesignManufactureBladesAssemblyTestingTheory  Procedure ResultsAnalysisEvaluation and DiscussionConclusionRecommendationsReferencesRelated Abstract The completion of this project would not have been possible without the help and assistance of my supervisor Prof. Paul Wagstaff and Kingston University lab technicians Dean Wells and Cliff Searle. Tremendous thanks must be given for all of their time and efforts in aiding with this investigation. It served as a good insight to the nature of an engineering project and the considerations which must be taken in order to stick to given deadlines. Project Introduction Types of Wind Turbine The type of turbine is defined by its method of creating rotation; lift or drag based. An example of a drag based turbine is the Savonius Wind Turbine design, Fig 1. Whereas a drag powered turbine uses the pressure difference on either side of the turbines axis to force rotation, a lift powered turbine utilises pressure differences around the surface of the blade itself. All modern turbines are lift based machines as even though drag based designs have improved significantly, the limitations involved are much greater than those of lift based turbines. According to Gipe, (1995, p171) â€Å"When examining the portion of the frontal area covered by the wind turbines blades, lift devices easily produce at least 50 times more power per unit blade area than drag devices.† Lift devices are then further defined by the orientation of their rotating axis or prop shaft; either vertical or horizontal axis. The two solutions each have their own relative advantages and disadvantages and therefore are suited for different applications. Horizontal axis wind turbines face the wind and use the lift produced to rotate the blades perpendicular to the wind direction. The gearbox and generator are usually located in the ‘hub’ at the top of the tower. Horizontal axis systems operate at a lower RPM but higher torque and can be more efficient than equivalently sized vertical axis systems. As they can be manufactured on a much larger scale they can produce much higher maximum power ratings also. Modern turbines incorporate a pitching device to allow the blades to reduce the lift they provide in high winds in order to prevent damage to the system without completely shutting down. The size of the large horizontal turbines however means they require larger average wind speeds to overcome the very large inertial forces to self start. It also then makes them very expensive to produce, transport, install and maintain. This is not helped by the fact the machinery is located at the top of the high towers. Horizontal systems must also face the wind in order to extract its energy so requires a yaw mechanism so it can reorient itself when the wind changes direction. This occurs electronically via internal motors with the larger turbines although simpler devices such a tailfin can be incorporated into smaller designs. This extra mechanical requirement only adds to the cost of installing and maintaining a large horizontal axis turbine. Figure 2 Vestas V164 7.0MW HAWT c/o vestas.com Horizontal axis wind turbines therefore, such as the Vestas V164, Fig 2, are usually deployed where the wind is relatively high, constant and predictable, usually either offshore or in sparsely populated areas to minimise visual impact for local residents. Vertical axis wind turbines operate at a higher RPM but lower torque than equivalent horizontal turbines. They can also accept wind from any direction so require no yaw mechanisms for when the wind changes direction. As they are generally smaller they create less visual objection and rotate with less noise. The fact the gearbox and mechanisms do not need to be as high as horizontal axis wind turbines means they are cheaper to install and maintain. If the wind speed does exceed the maximum, unlike the horizontal, the vertical axis turbine cannot pitch down its blades and must shut down to prevent the system being damaged. It is for these reasons that vertical turbines are suited to urban areas where wind direction can be lower and more unpredictable, as well as having less impact on the people living in the area. A common vertical axis wind turbine being installed is the Quiet Revolution QR5, Fig 3. Wind Turbine Theory   In order to complete the project successfully a solid understanding of the wind turbine principles that will affect its performance must be grasped so that they are considered during the design process. The aim of the turbine is to convert the energy in the wind into a useful form of energy, namely electrical energy. It does the by capturing the wind and rotating to drive a generator which converts the kinetic energy into stored electrical energy. The turbine blades of lift based devices are airfoil profile shapes which utilise the lift produced to convert it to a rotational force, i.e. Torque. The lift acts perpendicular to mean chord on a symmetrical airfoil profile. Because of this a vertical axis turbine can only utilise a certain component of this lift force due to the nature of its rotation. Figure 4 VAWT Blade Vector Diagram c/o traviscarrigan.com An optimum angle of attack must be achieved so that the profile is generating enough lift although with vertical axis wind turbines, if the angle of attack is too high the drag increases to the point where the resultant torque output is reduced. Horizontal axis turbines can operate at much higher angles of attack so that more of the lift is converted to rotational torque. Betz Limit The energy transfer between kinetic energy in the wind and the turbine cannot be 100% efficient. The limit of the maximum fraction of power any turbine can extract from the wind can be shown mathematically to be 16/27 – or 59.3%. This occurs when the velocity reduction ratio (b) is 1/3, Swift-Hook (2011). The velocity reduction ratio is the ratio between the relative speeds of the incoming wind to the wind leaving the turbine. The turbine system will also inevitably not be 100% mechanically efficient so the Betz limit of 59.3% is an ideal that can never be achieved. The most efficient modern turbines operate at 35-40% efficiency. Cyclic Loading As it is only when the blades are travelling into the wind they create lift, and therefore rotational force, the torque output of the turbine operates cyclically. Some turbine designs, such as the Quiet Revolution QR5 vertical axis wind turbine, Fig 3, have blades which occupy a range of angular locations and create lift along its complete length. This reduces, if not eliminates, the cyclic loading effects. Reynolds Number The Reynolds number is a dimensionless value which represents a ratio between the inertial and viscous forces of an object moving through a fluid. As it travels through the molecules of the gas they effectively attach to the surface of the object, creating what in known as a ‘boundary layer’. This boundary layer effects the aerodynamic properties of the object as molecules outside of it react with it as they would the object itself. This boundary layer is very complex to calculate and predict. The Reynolds number serves to provide a numerical, more objective description of the surface conditions so that the behaviour of the object can be better predicted and compared in experimental conditions. The Reynolds number is calculated as follows: Where:  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Ï  = density of the fluid ÃŽ ¼ = dynamic viscosity of the fluid ÃŽ ½ = kinematic viscosity V = relative velocity of the object to the fluid L = the length the fluid travels The higher the Re number, the better the attached flow over the object. Wortman (1983, p76) notes however that ‘small scale model tests are of questionable value because aerodynamic performance of the blades deteriorates at low Reynolds numbers.’ Solidity The parameter ‘solidity’ is a ratio of the combined blade area to the total swept area of the turbine. It is a critical factor for designers of wind turbines. To determine the solidity the following equation can be used, Paraschivoiu (2002, p57): Where:  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   n = number of blades C = chord length of the blades S = total swept area of the turbine L = the length the blades Tip Speed ratio A crucial factor in ensuring the turbine operates at maximum output is determining the optimum tip speed ratio, ÃŽ ». This is the ratio of tip speed compared with the speed of the wind which powers it. If the turbine rotates at a ÃŽ » which is too small most of the wind will pass undisturbed through the structure, meaning it is not extracting as much energy as possible. On the other hand if the blades travel at a ÃŽ » which is too high, the blades will be travelling through disturbed air from the previous one, lowering the aerodynamic efficiency, or even effectively acting as a wall blocking the wind from passing altogether (Manwell et al). Solidity of the blades will also have an effect on its output. Solidity is defined as the blade area divided by the total swept area of the turbine blades and the result is effectively a ratio. Project Definition The objective of this project is to redesign the existing vertical axis wind turbine and construct a functional model to test in the Kingston University wind tunnel. The project utilises previous investigations, most notably for the existing model components. Previous experiments have operated the turbine with a negative angle of attack meaning direct numerical comparisons will be limited. Recommendations on the design of the turbines construction will be taken on during the design phase in order to maximise the probability of a successful outcome. The parameters of the turbine will be defined based on basic wind turbine principles so that their effects can be observed on testing. Recommendations for further investigations or development of the current design will also be made. Project Aims The primary aim of the project is to gather experimental data to analyse in order to validate the design changes. During the design phase specific focus will be given to reducing the start up speed of the turbine as this will give the design a distinct advantage for real world applications. The method for achieving this will be to reduce the moment of inertia of the turbine by manufacturing a lighter blade design. The testing will also be based around investigating the effect of the augmenter on turbine output. Another parameter under investigation is the maximum achievable power of the turbine. This will be deduced by applying various loads under various wind velocities. Project Deliverables The deliverables associated with achieving the aims of the investigation are as follows: A Project Planning Report New blade concept design Detailed blade design CAD model Engineering Drawings Blade manufacture Complete turbine assembly Wind tunnel analysis Seminar presentation and Poster Final Report Background The turbine consists of an internal rotating structure surrounded by a metal augmenter which aims to direct the airflow onto the blades in a more controlled manner. The blades are a NACA 0018 symmetrical airfoil profile and are constructed out of fibreglass with a rapid prototype core mesh. The complete turbine can be seen in Fig 5. Figure 5 Previous Turbine Design The mechanism employed to allow a range of pitch angles (+5o to -10o) in the previous model can be seen below in Fig 6. The angle of attack was altered by rotating it about a pivot using a bracket with an extended slot. This was then secured in place by a small nut. It appears this was not strong enough as a shaft extending from the central spindle to the blade was also added to give extra strength to the trailing edge. Figure 6 Previous Pitch Fixing Mechanism There are 2 bearings mounted into two steel crosspieces to support the turbine, which in turn is supported by a large lattice framework. Below the turbine is a torque box hub concentric with the shaft. The augmenter consists of eight folded steel surfaces around the circumference to direct the airflow onto the incoming blades, simultaneously increasing its lift while decreasing the drag of the system as a whole by directing it away from the blades travelling out of the wind. The turbine is omni-directional meaning it should produce the same results regardless of wind direction. The upper and lower surfaces connecting the vertical surfaces are tapered toward the turbine to direct more of the available wind onto the blades. The previous model had been completed yet was not constructed to the optimum configuration that has been described. Also the maximum wind speed had been exceeded when it was placed in the wind tunnel which led to a catastrophic failure of the model as the RPM was too high and an imbalance in the rotor mass led to vibration, causing a collision between the turbine and augmenter. The augmenter was also distorted. Literature Review Ben Davis (2009) Ben Davis investigated various blade vertical lean angles to assess the optimum configuration. The conclusion was that 0o, i.e. no lean, gave the best power output results. The absolute data and results will not be comparable for this investigation though as the blades were pitched at a negative angle of 10o. David Camacho – Kingston University David Camacho identified that the ratio of the blades height (h) and the diameter of their rotation (d) plays a vital role in the overall efficiency and power output of a vertical axis wind turbine. This was determined to be at its optimum at h/d = 0.625 and has been shown that any deviation from this has a detrimental effect on the results so it is this attribute which took priority during the design process. David also investigated various vertical lean angles of the blades by using CAD and CFD to derive as above that 0o is indeed the optimum position. Max McDougall (2010) Max McDougall’s investigation is the latest and much of the previous structure has been salvaged in order to save time where manufacturing new components would be unnecessary. The data however is of very limited use for comparison as Max pitched the blades at -10o (with the leading edge closer to the axis of rotation than the trailing edge) – despite him quoting it to be +10o. For this reason the real data produced is redundant for the current investigation. The start up speed for the turbine was found to be reduced from 9m/s to 4m/s when the augmenter was included although without it required a manual start by hand. The upper limit of the wind speed in this investigation was over 20m/s – the current investigation would not expect to expose the wind turbine to such high speeds. It was also noted that the investigation should be restricted to operating the turbine at below 200rpm as deflections in the blades and prop shaft were visible at these speeds. This also is expected to be exceeded. Design Concept Generation Assessment Once an understanding of the task was gathered, work began on appraising the existing structure and assessing which remaining parts could be salvaged for the rebuild. The triangular pieces which fix the blades to the central spindle would have to be recycled regardless as they were costly and complex to manufacture. This was a driving factor with regard to optimising the height to diameter ratio. As mentioned previously the structure had failed catastrophically so deconstruction of certain elements was not as straightforward as possible. Once the frame was removed the cruciform pieces fixing the centre spindle to the supports were easily removed. The augmenter could then be removed leaving the skeleton of the turbine itself. Members that had been added to secure the blade angles had snapped leaving the remains of its shaft in the central nut securing main shaft. This subsequently had to be sawn off as the thread of the main spindle had been ruined. After cutting the thread again the remaining nut was removed and the model reduced to its component parts. Design Concept The decision was taken to reduce the height of the turbine blades to meet the h/d requirements for sake of time and ease of manufacture. The height of the blades was determined by the existing diameter which currently was 0.42m, hence: To reduce the weight as far as possible it was decided to manufacture them as a hollow structure from a lightweight composite material. This led to a concept which involves producing the complete blade as two separate halves and bonding them together. Detailed Design Blade Design As mentioned the blade concept is to have them as light as possible and achieving this with a hollow composite structure. The final design is shown below in Fig 7. The outermost shell is 265mm long at its outer edge. The end caps are thicker than the aerodynamic surface to aid its strength and allow for tapping threaded holes for assembly. This is the same on the inner shell so that the end caps have three times the thickness of the aerodynamic surface once assembled. Figure 7 Blade Concept Design The internal profile of the end caps for the inner shell must be altered from the basic NACA 0018 to allow for mating. This profile is shown in Fig 8. Figure 8 Internal Blade Profile Material Selection and Manufacture The blades were manufactured using ‘Depression Moulding’, Gay Hoa (2007, p19). One mould and blade half was made initially so that the thickness and finish could be assessed. Producing them in this way meant the exact length required for the opposite halve could be achieved and incorporated into the opposite mould. The material used for the blades is Kingston University stock composite of bi-dimensional woven prepreg Carbon Fibre with E650-02 42% Resin. As the material was hand laid and with prepreg the only consideration was the angular direction when defining the construction. Having a symmetrical layup is very important as unsymmetrical laminae cause a warped final product as a result of the curing and cooling cycle. A bending-extension coupling, Bij ≠  0, occurs where a force is exerted in the x and y direction of the lamina, Barbero (2011, p182). The definition of a balanced laminate is that ‘for every +ÃŽ ¸ there is another at –Î ¸Ã¢â‚¬ ¦; and for each 0o lamina there is a complimentary 90o lamina with the same thickness and material’ Barbero (2011, p184) although as mentioned the material and thickness considerations is negated by the use of prepreg. The laminar orientation is symmetrical and balanced at [0/90/0/90]. CAD Design A CAD model was produced for the entire assembly using the SolidWorks package, in order to assess its physical parameters at the design stage, Fig XXX. Figure 9 Complete Turbine Model The final turbine design has the following physical parameters: Blade Height (m) 0.265 Turbine Diameter (m) 0.424 h/D 0.625 Swept Area (m^2) 0.112 Blade Chord (m) 0.078 Blade Area (m^2) 0.02067 Number of Blades 3 Solidity 5.519 Manufacture Blades To manufacture the moulds a SolidWorks CAD model was made in order to be converted to an STL file which was loaded into the CNC milling machine, Fig 10, at Kingston University. The material chosen was high density foam readily available from university stock. Figure 10 Moulds in CNC Milling Machine Once the moulds were completed they had to be finished by hand. This included filing down the sharp edges around the outside of the billet in order to prevent any damage to the bag in which it was to be cured. More importantly, the inner surface of the mould needed to be smoothed to an appropriate surface finish as any roughness would be shown on the aerodynamic surface of the blade as the Carbon Fibre was cured in a vacuum. This would be detrimental to the efficiency of the blade so a rough sand paper was used, followed by a fine grade. Also in the corners the milling machine left a small radius form the tool. These were removed by hand to ensure a clean corner for mating of the two halves. Once the finish was satisfactory, heat proof tape was laid onto the mould surface, Fig 11, to improve its smoothness and also to allow easier removal of the piece once it was cured. Special attention was given to minimise the overlapping or gaps down the span of the blade as these also would be visible on the blade surface. The method of layup was to place the aerodynamic surface and end caps separately but with an overlap to form one solid piece. The Carbon Fibre was removed from the freezer where it stored and allowed to defrost in its protective bag. The profiles for the surfaces and end caps were marked out at the appropriate angles to the composite orientation and labelled for order of insertion, Fig 12. The initial surface pieces were laid at the correct 265mm length, and then increased consecutively by 1mm to allow for the required overlap at the seams. The surface and end caps were laid in alternate order, also alternating orientation on each respectively for strength. On the aerodynamic surface, four layers of Carbon Fibre were used but on each end six were applied. This then means that when the two halves are mated, each end is twelve layers thick three times that of thickness along the blade span. This extra thickness allows depth for holes to be tapped to secure it to the turbine structure and also gives strength to allow the loads being applied to be transferred over a greater area, reducing the risk of failure. After laying in each piece a roller was used to squeeze out any potential air pockets and while working the area was kept clean of dust or any small pieces of debris which may be added to the piece. The use of prepreg is useful for this as the resin content is higher than desired for the final part and the removal of this resin during curing helps to eliminate these. If any of these flaws in the material occurred they would create an impurity and potential weakness in the blade as it would act as a stress concentration point. Each 1% of these trapped in the laminate leads to a 7% reduction in intralaminar shear strength and any defects of 2% and above leads to a ‘significant reduction in compressive strength’, Barbero (2011, p74). The theory of imbalanced laminae was proven as a [0, 30, 90, -30, 0] lay up was attempted initially. The piece was removed from the mould and was indeed warped, Fig 13, which was most likely caused by inaccurate application of the 30o and -30o lamina. The completed layup was then wrapped in a breathable fabric. This will prevent any air pockets being caught in the bag under vacuum, Fig 15. Figure 14 Moulds Wrapped in Breathe Figure 15 3 Moulds in Oven for Curing Once the blades were laid in the mould the bag in which they were to be cured was prepared. The bag itself was cut to size and another sheet of the breather material inserted across the base for not only the mould to rest on but also for the nozzle. If this was not added the bag itself could be pulled onto itself, disabling the ability to remove all the air from the entire bag, rendering it useles. The bag was then sealed with a double sided rubber tape, taking extra caution to lay the bag material down with no folds or creases which may allow the entrance of air during the curing process. The functionality of the bag was tested by applying the nozzle before it entered the oven for curing, Fig 14. The entire apparatus was then placed in the oven for 1 hour at a temperature of 100oC. Once one section was produced the locations with four layers were 0.8mm thick once cured and cooled, and the locations with 6 layers were 1.2mm thick. This meant the second mould could be made and had a length of 262.6mm, with an altered profile of the end caps to incorporate the 0.8mmm reduction on the top half of the airfoil. Once the two halves were removed from their moulds, excess material was removed by filing it down. The excess material refers to small flanges which were created from the sheets being laid slightly over the side of the mould and also the radii on the internal corners of the longer half which may prevent the blade mating as intended when the shorter half was inserted into place. This process had to occur above an extractor fan whilst wearing a face mask as the airborne fibres created can cause severe damage to the lungs if inhaled. To bond the pieces to form a complete aerofoil araldite was applied to where the end surfaces meet as well as along the leading and trailing edges and the whole thing clamped together while the adhesive set, Fig 1 As the leading and trailing edges had a thickness of approximately 0.8mm and therefore a very small contact area for the adhesive to bond, a few small gaps still were visible. These would have a negative impact on the aerodynamic properties of the blades so a hardening filler was used roughly and filed down once set. Assembly Once all the components were ready the turbine was assembled in the machine workshop. One new auxiliary part was made from the previous assembly and that is shown in Fig 17. A piece of 5mm Aluminium was fabricated and folded, and threaded holes located to support the struts which fix the trailing edge. The previous design had inserted these struts into the nut on the central spindle. This however made disassembly difficult and the solution shown should resolve this. It also means there is more length of strut locked into not only the Aluminium but a further nut is added to increase its strength, following the recommendation of McDougall (2010, p38). It is important that all three blades are identical in weight in order to minimise the imbalance which may occur when the turbine is rotating. As the turbine will operate at high RPMs any imbalance will have a great effect. Two of the blades weighed in at 52g and one was 53g. By re-bonding the metal end caps to the blades increased their weight slightly but meant it was possible to balance them perfectly. Once the correct configuration of blades and caps was found all three blades weighed 68g. The central shaft also had to be turned down and threaded to allow assembly for the reduce turbine height. Testing Theory   The goal of the test is to measure the power output of the turbine at certain wind speeds. To do this, under a known load, the RPM of the turbine was measured so a value for the power produced could be calculated using: Where:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   P = Power (W) T = Torque (Nm) ÃŽ ± = Angular Velocity (rad/s) The conversion of RPM to angular velocity is: Knowing the amount of power produced by the turbine enables us to calculate a value for the coefficient of power under those conditions using, Paraschivoiu (2002, p320): Where:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Ï  = Air Density (kg/m3) V0 = Wind Speed (m/s) S = Blade Area (m2) The pitch angle of the blades will be set at +5o as this is the angle for best L/D, Airfoil Investigation Databse www.worldofkrauss.com. Procedure Two phases of testing took place in order to compare data to that of the previous design. Initially the turbine was exposed to the wind without any load and the wind velocity increased to the point where the turbine self started. This was then repeated with the augmenter added so that the effect on start up speed could be observed. Then by applying various loads to the turbine at constant wind speeds, the maximum power for that wind speed can be found by plotting a graph of Power vs. ÃŽ ±. By repeating this at increasing wind speeds a curve of Maximum Cp vs. Wind Speed should identify a trend and possible suggestion of at what wind speed the absolute maximum power may be achieved. When taking measurements of turbine RPM care must be taken to ensure the blades are not accelerating or decelerating. To ensure this the value on the Tachometer must remain constant for 20 revolutions or 30 seconds, whichever is greater. To apply the load the test rig was assembled with a rope wrapped around the shaft of the turbine. On one end was a mass hanger, supported by a pulley and the other end was fixed to the supporting framework. By the end with masses a torque is applied to the shaft by way of friction from the rope. Using the following equations the torque being applied, and therefore the working torque of the turbine, can be calculated. Where:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   T1 = Resultant resistance (N) T2 = Tension (N) ÃŽ ¼ = Coefficient of friction ÃŽ ² = Angle of contact on shaft (rad) The angle of contact on the shaft was set at 180o, which is ensured by maintaining the two lengths of tether were exactly parallel to each other, Fig 18. The coefficient of friction, ÃŽ ¼, was found by experiment to be 0.917. The resistance being applied to the shaft, found by resolving T1, can then be converted to an effective applied torque using the equation: Where:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   T = Torque (Nm) F = Force applied (N) d = Shaft radius (m) The power of the turbine under each condition can then be calculated using the equation below: Where:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   P = Power (W) T = Torque (Nm) ÃŽ ± = Angular Velocity (rad/s) The graph of Torque vs. ÃŽ ± should be a linear function due to this equation. From this data a graph of Power vs. ÃŽ ± should be a polynomial curve with a maximum value occurring between maximum torque and maximum angular velocity. The lattice framework was stiffened to minimise vibration and flutter effects when it was in operation. To do this it was first raised off from the relatively loose metal beams running parallel to the tunnel and rested on large masses. It was also weighed down by heavy objects from the wind tunnel lab, Fig 19. Figure 19 Lattice Framework Stiffening The upper framework still felt unstable so it was G-clamped on both sides to the wind tunnel opening using surplus beams from the wind tunnel lab, Fig 20. These measures ensured there was minimal vibration caused by the framework itself being deflected in the wind. Figure 20 Lattice Framework Supports The procedure was then repeated with the augmenter in place. The top section of the framework was removed as a whole, Fig 21 and the augmenter lifted over the top of the turbine. This allowed the turbine to remain in position and minimise any variables that might be affected. To secure the augmenter, an M10 thread was made in the lattice members so a long bolt could be screwed in. On the other side of the bracket a nut and washer were secured, Fig 22, to ensure no slippage of the augmenter which may lead to collision with the blades. This was identical at 4 locations on both top and bottom of the augmenter. Results The start up speed of the turbine without the augmenter was 4.8m/s and with the addition of the augmenter it was reduced to 1.1m/s. Initially the turbine was run with no loading. When the turbine was rotating at low wind speeds without the augmenter it did not acquire true lift and remained at a low RPM. It was not until the wind speed was raised to around 5m/s that the turbine would accelerate to a significant RPM. When the augmenter was added the turbine RPM at lower speeds was proportional to those at higher wind speeds. The results of increasing the wind velocity on RPM of the turbine are shown in Fig 23. Figure 23 Graph of Wind Speed vs. RPM The wind speed at which the turbine would accelerate into lift appears to be correlated to the start up speed. When no load was applied and the turbine was in lift the relative RPMs with and without the augmenter are almost identical. It was also observed that the turbine acceleration would sharply increase once it had reached 150-165RPM. The addition of the augmenter therefore also had a significant effect on maintaining a constant tip speed ratio at lower wind speeds because of this – displayed in Fig 24 Figure 24 Graph of Wind Speed vs. Tip Speed Ratio Loads were then applied at a wind speed where the turbine was in lift. The torque applied was proportional to the reduction in RPM for both cases, which was expected Figure 25 Graph of Torque vs. RPM without Augmenter Figure 26 Graph of Torque vs. RPM with Augmenter The gradient of the trend lines serve as a good indication of the reliability of the results. All are relatively parallel, in both cases, except for at 8m/s with no augmenter. The trend line gradient exceeds that of the data at 9m/s which suggests the values found are too high. This would have been caused by anomalies or errors in the execution of the experiment. Looking at the trend line gradients for all speeds without the augmenter suggests the behaviour of the turbine is less predictable than when the augmenter is added. Higher loads were applied than the data points shown although the turbine decelerated to zero in these cases and so has been omitted for the purpose of analysis. The complete data set can be found in Appendix 1. Analysis From the raw data displayed in the previous graphs, the power of the turbine could be calculated. The graph of turbine power is shown below for each case with (Fig 28) and without (Fig 27) the augmenter. Figure 27 – Graph of Power vs. ÃŽ ± without Augmenter Figure 28 Graph of Power vs. ÃŽ ± with Augmenter Polynomial trend lines have been added to predict the entire curve based on the data found. The peak of these curves indicates the optimum power and corresponding angular velocity for the investigated wind speeds. These figures were read off the graphs and then plotted as a series to compare the augmenter effect on maximum power at different wind speeds, see Fig 29. Figure 29 – Graph of Max Power vs. Wind Speed The augmenter appears to increase the power of the turbine at all wind speeds. The data from testing the turbine without the augmenter at 8m/s has been shown to be higher than is realistic. If this were to be repeated the maximum power at 8m/s could be expected to be around 0.8W in this configuration. Evaluation and Discussion There are several elements of the turbine assembly which can be improved to increase the efficiency and therefore the power output of the design. Blades The blades were a novel design and as a result were subject to imperfections because they are essentially the first article. The surface of the blades after they had been cured had a very slightly rough texture. This will increase the skin friction drag when the turbine is in motion. Also there was remains of the adhesive from the tape which acted as a barrier between the piece and the mould. It was not possible to remove this although several methods were used. Thinners, ethanol and a heat gun were all used to no effect. The process of filling the gaps post-bonding of the two halves also could have been improved as the trailing edge was not as thin as possible. This will induce extra drag as the air struggles to reform in the stream as the airfoil travels. There was also audible rattling of auxiliary structure in the region of 550-600rpm. After examination this was found to be due to the screws inserted into the threaded holes on the blade ends. It was found that on one of the blades, the screw attaching the bracket closest to the leading edge was not locking when screwed up fully. This meant it was slightly loose and the bracket itself was vibrating. The turbine was run up to 800rpm in this state so there was no fear of failure yet it is not a desirable situation. The cause is down to the weak nature of the thread inside the composite. For future designs, a rawl plug or socket to support the screw. Another source of inefficiency was the drag caused by strut members securing the blade pitch angle. If possible a design should be developed to secure the blades at the correct angle without these members. Yet more inefficiency would have been caused by the spindle arm pieces which connect the blades to the shaft. From a previous experiment where the turbine failed and general wear and tear from others have left these pieces scuffed. At the extreme ends of these there are extension pieces to increase the turbine diameter. The mating of the two has left gaps which will trap air when it is rotating. Both of these factors will also increase the drag unnecessarily. The augmenter was not altered in order to complete the project on time. The preferred option would be to shorten it down to leave approximately 10% of the blade height distance between the edge of the blade and the upper and lower cowling. Also the upper and lower rim itself would be at best effect at 30o to the incoming wind; it presently sits at around 10o. This would be a useful update for future investigations. The testing procedure is open to scrutiny. The absolute value for power output is dependent on the coefficient of friction used between the tether and the shaft. The method for deducing this was to fix the turbine blades and place a mass hanger on two pulleys at either end of the tether. Imbalanced masses were added to the hangers and the rate of acceleration that the heavier one fell was calculated. Knowing the acceleration, a difference between that figure and 9.81m/s 2 of gravity was assumed to be caused by the friction applied at the shaft. This resistive force was converted to a friction coefficient for the materials. The timing of the falling masses was repeated 10 times and all values were in a range of 0.2 seconds. The value of 0.917 however seems high and errors may have occurred in either the timing or the height at which the masses were dropped. This doesn’t mean the results are worthless though. As long as the same materials and hence coefficient of friction is used, which it was, then the varying results for different conditions are still valid if only as a comparison and therefore the aim of finding optimum conditions is still achieved. A further alteration which would of much improvement to the investigation is the material used for this tether. At high applied loads then the tether ‘burned out’ as the turbine was at high RPMs also. This meant applying a new tether very often and possible discrepancies in the results. A better material or even better method, with greater accuracy would enable the absolute results to be much more reliable. Conclusion The addition of the augmenter not only greatly reduces the start up speed of the turbine but improves performance, especially at low wind speeds. When there is no loading and the turbine is in lift the augmenter does not affect the RPM however with no load the turbine is not useful. It is only when a load is applied that power can be extracted. The augmenter does have a significant effect on this and allows the turbine to not only operate with a higher power output but also appears to give greater predictability as a result of directing the airflow. Recommendations The following recommendations are made to improve the investigation in the future: References Gipe, Paul (1995) Wind Energy Comes of Age, John Wiley Sons Inc, Canada Davis, Ben (2009) Vertical Axis Wind Turbine Blades for Urban Environments, Unpublished MEng Dissertation, Kingston University, London Perera, Kapuruge (2009) Analysis and Development of a Vertical Axis Wind Turbine, Unpublished Final Year Individual Project Report, Kingston University, London Bhatt, Hardik (2009) Vertical Axis Wind Turbine, Unpublished Final Year Individual Project Report, Kingston University, London McDougall, Max (2010) Vertical Axis Wind Turbine Project, Unpublished Final Year Individual Project Report, Kingston University, London Pathmanathan, A.V (2008) Analysis on a Vertical Axis Wind Turbine, Unpublished Final Year Individual Project Report, Kingston University, London Gay, D Hoa, Suong. V (2007) Composite Materials Design and Applications – 2nd Edition, Taylor Francis Group, USA Barbero, E.J (2011) Introduction to Composite Materials Design – 2nd Edition, Taylor Francis Group, USA Wortman, W. J (1983) Introduction to Wind Turbine Engineering, Butterworth Publishers, USA Paraschivoiu, I (2002) Wind Turbine Design, Ecole Polytechnique de Montreal, Canada Airfoil Investigation Database, Available at worldofkrauss.com, accessed on 8/3/2011.

Enlightened Shareholder Value Essay Example | Topics and Well Written Essays - 2250 words

Enlightened Shareholder Value - Essay Example The concept of shareholder value holds that company directors must tailor their policies to be in line with the interests of the shareholders of the company1. Directors are therefore expected to steer the operations of the company with the maximization of the shareholder’s interests as the main priority. The United Kingdom established the Company Law Review Steering Group (CLRSG) in late 1990s and mandated it to come up with a detailed review of English company law. At the end of its exercise, the CLRSG noted that the country’s legal system, like other Western jurisdictions, prefers shareholder value. The CLRSG indicated that the current legal system reflects the reality that business organizations are run in such a way that the shareholders often benefit. That is, the legal system confers upon shareholders absolute powers in the management of the local companies, such that the mandate of the directors is basically to exercise delegated power. Additionally, the CLRSG st ated that the crucial goal of business organizations is to create maximum gains for the investors in the short term as opposed to long-term goals2. This paper examines the argument that the enlightened shareholder value principle is a sophisticated restatement rather than a refutation of the principle of shareholder primacy. ... This is especially true even after the latest repeals to the body of law as envisaged in the Companies Act 2006. It is arguable that, unlike the largely fair structures of company law, English case law has consistently reaffirmed the primacy of shareholders. The courts have traditionally held that any public business organization should be managed to the advantage of the membership or shareholders3. However, the CLRSG has recommended a change of tack. To this end, the reviewing body supported the implementation of the principle of enlightened shareholder value (ESV)4. Section 172(1) of the Companies Act 2006 mainly captures the provision for the ESV. The provision reaffirms the management of every company should be done with respect to the interests of the shareholders. The section basically upholds the principle of shareholder value, but limits the formerly absolute benefits of the group by introducing the rule and the need for due respect for the interests of other stakeholders5. T his is arguably a proposal for a new doctrine in the English law, in the sense that section 172(1) conditionally supports the primacy of the interests of the shareholder. The requirement, which could be interpreted as the enlightened aspect of the shareholder value, underscores the doctrine of due attention to the value of non-share-holders as well. The latest law has brought about far-reaching legal implications in the understanding of the provision. Responses to the new clause among legal opinions may be divided into two categories: supporters and detractors of the enlightened shareholder value rule. It can be argued that section 172(1) is actually a modest but well thought-out principle that will balance the

Architecture and Urban Projects Essay Example | Topics and Well Written Essays - 5000 words

Architecture and Urban Projects - Essay Example For the progress of the Gaza strip in general, and the city of Gaza in particular, there is the need for Israeli approval and loosening of its iron grip over the area it once occupied and continues to control economically and militarily. This is possible only if guns on both sides fall silent and give way to a joint political and economical panel. The Gaza Strip is located 45 meters above sea level bordering the Mediterranean. Over the last 50 years its population has risen dramatically from 50,000 in 1948 to about 1.2 million in 2002, with population density of between 20,000 to100,000 per square kilometer in certain places, making it one of the most densely populated areas in the world. Half of the population consists of refugees displaced after the creation of Israel. (1) The old city of Gaza admeasures about one square kilometer and is enclosed by a great wall with gates serving as entrance and exit points. With the rise of population and activity, it spread out on the north, south and east of the old city limits. Places of interest are the Mosque of Al Sayed Hashem, the Mosque of Ibn Marwan, the Great Omari mosque, the Sheikh Abul Azm sanctuary, the the Sheikh Ailin sanctuary, Napoleaon's fort also known as Al Radwan Castle, Tell al Mintar, and the church of St Porphyrius. The Gaza city is located between Israel and Egypt, and is the principle city of Palestine. The northern suburbs of Gaza are mazes of crumbling buildings and present a picture of overcrowded populace, living in abject poverty. The historic part of the city is located in the heart of the city. The main street named Omar al Mukhtar Street runs east to west from Al Shuja'iyva quarter and extends up to the sea. There are tourist resorts with swimming pools, or facilities for swimming at the beach. (1) According to its Municipal plan, the city is primarily divided into four areas: Area B, Area C, Area of High-rise buildings, and Tourist area. In keeping with the civic rules, Buildings in Area B must be situated 3 meters away from the street and 2 meters on other sides. It must be built on a plot admeasuring at least 250 square meters, and must not consist of more than 5 floors, including the ground floor. The building must not occupy more than 60% of the plot. Buildings in Area C must be situated 2 meters away from the street and 1 meter on other sides. It must be built on a plot admeasuring at least 250 square meters, and must not consist of more than 5 floors, including the ground floor. The building must not occupy more than 80% of the plot. High rise buildings overlook streets at least 20 meters wide and extend from east to west of the city. The plot must admeasure at least 1000 square meters and the building must not occupy more than 50% of the plot. The tourist area is located 400 meters to the east of the coast line, and the detail plan is being drawn. The Gaza municipality oversees