Monday, November 25, 2019
Philosophy of Music Education in the Indian Context Essays Philosophy of Music Education in the Indian Context Essay Philosophy of Music Education in the Indian Context Essay These ends must be the first and first ground why we teach music. To transfuse an even greater apprehension and love of the sphere therefore enabling our pupils develop a echt involvement and go on a life long journey thatÃ¢â¬â¢s undertaken in changing grades and through diverse functions. Phenix ( 1986 ) emphasis on the fact that cognition of methods makes it possible for a individual to go on larning and undertake enquiries on his ain ( p. 11 ) . Estelle Jorgenson in her book Transforming Music Education articulately describes the demand for music instruction to be transformed for the really ground that kids be able to go on developing their cognition beyond the schoolroom. Effective music instruction is built of a foundation that encompasses treatments. ends. stuffs and schemes. based on a teacherÃ¢â¬â¢s cognition and experience of music and kid development. educational guidelines and overarching. and developing doctrine of music education ( Fiske. 2012 ) . Before I elucidate my doctrine about music. I recognize the demand to clear up my base as a music pedagogue who is passionate and determined to promote the position of music instruction within schoolrooms around India. My Musical Experiences Music has ever been a portion of me for every bit long as I can retrieve. My earliest memories of music. particularly the public presentation facet. goes back to when I was three old ages old and sang a solo for a Christmas Concert that was organized by the wireless station that my male parent worked at. I have memories of him kneeling on one articulatio genus and playing the guitar for me while I sang after which I was delighted to have a large nowadays from Santa. Ever since. I have enjoyed acting. and have so felt so comfy on phase. All along I grew up listening to Christian Gospel music and many modern-day agreements of anthem. Auxiliary to that my male parent offered me a rich experience of Indian Hindu devotional music. I learned vocals by ear and didnÃ¢â¬â¢t realize what I was losing at this point. conceive ofing what I learned in music to be the lone manner to absorb and internalise it. Performing was something that I enjoyed making and it came of course to me. partially because of my early induction into taking worship at church. My true trial of endurance came about when I was introduced to Western Classical Music at the age of 14. through the survey of two old ages of piano. My instructor. like many others around. displayed an highly formalized attack and didnÃ¢â¬â¢t do much to spread out my apprehension of music beyond what was on the page and how I was supposed to read it. In response to this method I didnÃ¢â¬â¢t enjoy larning from the pages of notated music books. every bit much as I did larning by ear. and I continued to develop as a instrumentalist who played by ear and improvised at will. Analyzing opera during undergrad was a seeking stage for me because of my inability to connect the dots every bit easy as I should hold been able to. My aural accomplishments remained first-class and I sometimes relied on that to transport me through certain stages. Hard work and finding became my slogan. and I spent hours to understand and hone music that was assigned to me. as I wanted to make my really best. Although I had composed vocals earlier. without notating them. the survey of music theory opened up a whole new universe for me. I could now add assortment and profusion to my music through the constructs I was larning. Music became a new linguistic communication for me ; I was captivated by the manner it lent itself to diverse experiences through different musical functions ( something that I wasnÃ¢â¬â¢t cognizant of or didnÃ¢â¬â¢t wage attending to earlier ) . As a Music Teacher Although I ab initio joined a conservatory to analyze vocal public presentation. I found myself profoundly drawn towards music instruction. and during my 2nd semester decided to larn more about inventing meaningful and persuasive trategies to better the criterion of music instruction in India. This thought emerged from an apprehension that I had felt about cheated for holding lost out on so many old ages of analyzing music officially. yet efficaciously. I didnÃ¢â¬â¢t have a pick because structured music direction merely wasnÃ¢â¬â¢t available at all the schools that I studied in. or the quality of direction didnÃ¢â¬â¢t serve the intent of educating or informing pupils like me. What gave the feeling of a music class/lesson at school was in world an enthusiastic manner of maintaining pupils occupied for 40 proceedingss in simple vocalizing. with a concert for parents every one time a twelvemonth. We learned vocals by rote to execute them. twelvemonth after twelvemonth. During those old ages though. I didnÃ¢â¬â¢t recognize the restrictions that this system came with and continued to bask the fact that I was in choir and able to sing. This vacuity remains mostly seeable and unattended to in schools today. although some music pedagogues in the recent yesteryear have taken immense stairss towards bettering the quality and effectivity of their direction in schoolrooms around India. Their attempts nevertheless remain preponderantly an enthusiastic enterprise. What is desperately required is surely something much more than sincere learning. It calls for a transmutation of the present system. giving room for every kid to have superior music instruction that fits into the whole. The demand of every pupil being met in a transformed educational model that invariably reshapes itself to suit new thoughts and schemes. After all. as Regelski ( 2003 ) justly points out that music ( music instruction ) is for everyone and non merely for an elect few. The turning point in my determination to eventually learn music myself came about when I enrolled my four-year-old girl. Tiara. for after-school piano lessons. I hoped to give her a head start. with the apprehension that she neednÃ¢â¬â¢t have to confront the same challenges in larning music. like I had to. However. after a few categories. I realized to my complete dissatisfaction that there was no construction. no idea and imaginativeness. and no lucidity in what was being thought to her. Her fingering on the piano was all over the topographic point for the two vocals that her instructor worked on Twinkle. Twinkle Little Star. And Baa Baa Black Sheep Her instructor ( I subsequently learned wasnÃ¢â¬â¢t introduced to classical notation ) . taught her these vocals by composing letters in a book and teaching her to perpetrate it to bosom. Lesson after lesson they would follow the same lineation with no accent on any other musical facets whatsoever. I decided I wasnÃ¢â¬â¢t traveling to take this lying down! I had to make all within my capacity to alter the face of music instruction. as the huge bulk of people understand it. I began analyzing about music instruction as good. to inform and fit myself for the undertaking at manus. Around this period. my voice teacher encouraged me to train pupils in voice. and I began shying off from it believing I was under qualified and needed many old ages of survey to get down learning. However. with a newfound passion and energy. I accepted to training some of his voice pupils and besides began to learn little groups of pupils on the history of music ( because I loved larning about it ) . Meanwhile. I started developing both my immature girls at place invariably developing new thoughts and schemes to present musical constructs to them. A friend noticed my instruction manner and asked if I would learn her girl excessively. and therefore began my professional journey as a music pedagogue. Four old ages since so. I find myself accountable for the music direction I offer to over 250 kids across assorted age groups. who are portion of my school. The demand is so great within schools. and merely a few pedagogues are willing to take the excess attempt of educating themselves and being channels of superior music instruction-catalysts of kinds. I am blessed to hold a squad of 10 instructors who portion in my vision and work aboard me in leaving music to the kids who are portion of our music school. Harmony . My long-run vision is to heighten the music plans in India for the improvement of as many kids as possible. Persons donÃ¢â¬â¢t realize what theyÃ¢â¬â¢re losing until theyÃ¢â¬â¢ve been given a gustatory sensation of it. a glance of the bigger image ( much like my instance ) . Through our school public presentations I aim on supplying a window for the alteration to take topographic point. A transmutation that non merely affects my pupils. but others around them every bit good through their personal interactions with each other and the community as a whole. My Personal Philosophy A field or subject without philosophical counsel. without critically examined ideals and committedness to their alteration in visible radiation of the diverse and altering demands of those it seeks to function. is more kindred to an business han a profession ( Bowman A ; Frega. 2012. p. 23 ) . For my vision to bear fruit and demo grounds of going something concrete. I realize the demand to develop my doctrine of music to an extent that equips me with the necessity tools to be able to originate the alteration that I seek after. In the words of Jorgenson ( 2008 ) . I want to unearth beneath the superficial and incontrovertible accomplishments to believe about the thoughts and rules of music instruction. the things that drive and shape . Harmonizing to Kivy ( 2002 ) . A pattern or subject or organic structure of cognition. so. seems to go eligibleÃ¢â¬â¢ ( If that is the right word ) for doctrine. decently soÃ¢â¬âcalled. when it becomes for us a manner of life: when it cuts so profoundly into our natures as human existences that we are impelled to research and uncover its innermost workings ( p. 7 ) . It is necessary for me to clarify the major dimensions of musical experience so I can effectively offer them to. and nurture them within. my pupils ( Reimer. 2003. p. 9 ) . this despite the passion and strong belief with which I teach and advocate the demand for humanistic disciplines in schools. I have begun to develop a interactive mentality in my doctrine of music instruction after my reading and researching the literature. coupled with practical experiences over the last few old ages. Reimer ( 2003 ) points out A interactive mentality is one unfastened to cooperation as an option to contention. to seeking for points of understanding or meeting as an option to fixating on strife. to acknowledging niceties in which apparently opposed positions are capable of some degree of contention ( p. 30 ) . I agree with ReimerÃ¢â¬â¢s democratic position that musical significance is intending that individuals choose to give to and take from music. based on their life experiences and their musical orientations. He farther adds that there is to be no one right way . and calls for an version of a interactive blend in music instruction. Music must affect determination doing through understanding and connexions within a peculiar function ( Reimer. 2003. p. 213 ) . Eisner ( 1987 ) illuminates the demand for a course of study that exploits the assorted signifiers of representation and that utilizes all of the senses to assist pupils larn what a period of history feels like ( p. 7 ) . Similarly. offering pupils a footing for understanding music in all contexts involves a thorough geographic expedition of musical significance within its unequivocal parametric quantities. along with contemplation or contemplation. Introducing pupils to the music and other art signifiers of assorted civilizations is a fantastic manner to broaden their apprehension of the significance of music. A pupil does non necessitate to lose his ain musical individuality in order to analyze other music. On the contrary. in larning about other music. a studentÃ¢â¬â¢s life is enriched. Reimer provinces. In the spirit of adding to the ego instead than replacing other egos for oneÃ¢â¬â¢s ego. the survey of the music of foreign civilizations enriches the psyches of all who are engaged in it ( p. 191 ) . Music and Meaning As advocators of music. music pedagogues are frequently expected to show the significance of music through words. yet words are incapable of genuinely depicting the beauty and emotion felt through experience. The concern is non to get at a definition and to shut the book. but to get at an experience ( Ciardi. 1975. p. ) . Ciardi states that there still lingers belief that a dictionary definition is a satisfactory description of an thought or of an experience ( p. 1 ) . Wordss may try to depict music. yet true significance must be derived from the existent music experience Reimer ( 2003 ) discusses the difference between significances drawn from words or linguistic communication and the significances found through music. He writes. Language is create d and shared through the procedures of conceptualisation and communicating. Music is created and shared through the procedure of artistic/aesthetic perceptual structuring. giving significances linguistic communication can non represent ( p. 133 ) . The existent power of music lies in the fact that it can be true to the life of feeling in a manner that linguistic communication can non ( Langer. 1942. p. 197 ) . Phenix ( 1986 ) highlights the demand to look for aesthetic significance in music concluding that at that place has to be a delicate balance between descriptive proposition that serves the intent of puting out a historical background and leting for freedom to derive perceptual characteristics. Though music may arouse emotions in my pupils as they compose or serve as an mercantile establishment for their feelings when they perform. the ultimate significance of music lies in its ability to symbolize/portray profoundly felt emotions. In the pages of his article. How Does a Poem Mean. John Ciardi ( 1975 ) portions with the reader his position that linguistic communication is non capable of wholly conveying the significance that is discovered through experience. Populating through the poesy is more powerful than trying to construe it. I believe that linguistic communication does. nevertheless. function a intent of heightening and is required when learning for musical significance. Wordss such as enunciation. metaphor. beat. and antagonistic beat describe elements that lead to the apprehension of signifier. Once a pupil can place alterations in the signifier through public presentation. he will hold identified the verse form in action ( p. 95 ) . He will no longer inquire what the verse form means but will see how it means ( p. 95 ) . Ciardi suggests inquiries such as. Why does it construct itself into a signifier out of images. thoughts. rhythms? How make these elements become the significance? and How are they inseparable from the significance? ( p. 100 ) . These inquiries are helpful in taking a pupil to the ultimate meaningful experience. Similarly. music pupils may utilize their cognition of musical elements. such as beat and kineticss. to see how a piece of music agencies. Reimer ( 2003 ) says linguistic communication has the indispensable map of unwraping and explicating the music. Music elements are inseparable from the public presentation of the music as they help to explicate the musical experience. On their ain. nevertheless. words and definitions remain dull and exanimate. I believe pupils should be immersed in the experience. while in a chorus. executing their instruments and listening to those around them. Meaning can be discovered through active engagement in music and through the emotion and beauty the music portrays. for Music agencies whatever a individual experiences when involved with music ( Reimer. 2003. p. 133 ) . CiardiÃ¢â¬â¢s ( 1975 ) statement: It is the experience. non the concluding scrutiny. that counts ( p. 3 ) is peculiarly dramatic. The Indian society topographic points high accent on scrutinies in music as with other topics. really frequently overlooking the demand for pupils to value their experience through the procedure of acquisition. I sometimes experience pressured by the community to run into high concert public presentation outlooks and good scrutiny consequences. Although I recognize that public presentation and the International music test is a fantastic chance in which pupils can portion their music with the community. or understand their degree of competence. the true contemplation of significance in the music should be experienced in daily music devising within my schoolroom. I do my best non to concentrate on the scrutiny repertory entirely but to include other music as good giving them a opportunity to pull out significances and see the music. Ciardi ( 1975 ) describes a verse form as a dynamic and living thing ( p. 10 ) . He continues saying. One experiences it as one experiences life. One is neer done with it: every clip he looks he sees something new. and it changes even as he watches ( p. 10 ) . Similarly. music is capable of uncovering something new each clip it is experienced. The significances my pupils derive from an initial hearing of a piece of music may be immensely different than the significances understood months or old ages subsequently. The significance of music constantly alterations with personal life experiences and new positions. Reimer claims. Music instruction exists to foster peopleÃ¢â¬â¢s potency to derive deeper. broader. more important musical meanings ( p. 133 ) . I believe my pupils should deduce their ain significances from the musical experience and without my influence. By explicating significances to them. I face the fright of projecting into limbo the jubilation of their ain alone experience with the music. much the same manner a linguistic communication instructor might. in more ways than one. take away from the experience of a pupils feelingful experience of poesy as she explains the significance in the poetries of the verse form. Alternatively of learning what music means. I will teach pupils on how music means. enabling them to deduce significance from experiences that occur beyond the schoolroom. and within their ain functions. Feeling through Music Music does for experiencing what linguistic communication does for thought ( Bowman. 1998. p. 200 ) . As a instrumentalist. I understand the power of music to arouse feelings. Listening to or executing a great work of music in a concert hall may convey cryings or icinesss to the instrumentalist in a manner that lone music is capable. Similarly. studentsÃ¢â¬â¢ emotional lives may be heightened by experiences in the schoolroom. Harmonizing to Reimer ( 2003 ) . the emotional dimension of music-its power to do us experience. and to know through feeling-is likely its most of import shaping characteristic ( p. 72 ) . In Western history. emotion has frequently been regarded less valuable than mind ( Reimer. 2003 ) . Some people do non see the humanistic disciplines to be every bit of import as other nucleus topics such as math and reading in instruction due to the belief that humanistic disciplines are based on emotions and non concluding or mind. Recently. nevertheless. scientific bookmans have begun to acknowledge that human intelligence. or knowledge. is exhibited in a assortment of signifiers. straight related to maps of the organic structure. and tied to experiencing. Dimensions of the head. one time thought to be separate and unrelated. are now known to work together. lending to the things we know and experience. Anthony Damasio. a research brain doctor. believes feeling is likely to be the cardinal factor in human consciousness itself and an indispensable ingredient in human cognition ( Reimer. 2003. p. 76 ) . The capacity to experience pervades and directs all we undergo as life. cognizant creatures ( p. 8 ) . Direct experiences of feeling are embodied in music and made available to the bodied experience of those engaged with it ( p. 80 ) . The usage of descriptive and symbolic linguistic communication in the schoolroom. in the instruction of a varied repertory of expressive music. AIDSs in pulling out these responses of experiencing from pupils. Including music that is heavy and loud or delicate and light will convey out an array of feelings. I believe pupils should be given an chance to joint these feelings through journaling and in-class treatment.
Friday, November 22, 2019
Analyzing Aspects of Service Recovery - Essay Example In relation to theoretical aspects of measuring service quality in healthcare, it is important to note that the issue of quality in healthcare services always generates immense pressure to the healthcare providers (Rubenstein 2006, p. 70). It is of paramount importance that the patients get assurance of quality care and services that they subscribe to. It is also reasonable when the customers and patients expectations are not only met but also clearly understood under the constraints the hospitals must operate in. It can be quite difficult to measure the quality of services because intangible specifications are the ones used to determine it. An example is colour, width, height, depth among others. Many organizations have chosen a methodology called SERVQUAL (service quality) to measure the quality of their services. It is a service quality questionnaire that uses 5 dimensions in its quest for quality. The five dimensions include: responsiveness, reliability, assurance, empathy and ta ngible qualities such as appearance of physical facilities among others. Each dimension is measured on a scale of 1 to 7 together with its expectation and perception. The weight of each point is done according to customer importance (Schoeman 1992). The score from each dimension is then multiplied by the weighting. After this, the expectation score is subtracted from the perception score to get the Gap Score. If the Gap Score is negative, it indicates that the actual service (the perception score) is below expectation (the expected score). The Gap is the reliable indicator of the five dimensions of service quality. Decision making models can help the health care sector to assess the perceived service quality in the sector (LaCombe 1995, p. 558). . The model rates performance of hospitals. Hospitals should put more emphasis on providing health care services with empathy, reliability and professionalism to give qualified services that are satisfactory. The hospitals can improve their service quality and better service delivery to their consumers if they addressed their individual issues highlighted by SERVQUAL methodology. Considering intergenerational service preferences in health service management and delivery, health care needs vary with age and health care for the older persons has generated a number of services and programmes. This is in response to the need of a more oriented and community-based care for the ageing population. In America, the young population is fast changing to the middle-age population. This has resulted to a greater demand for health care services and products and vast competition amongst the health care providers (Porter and Teisberg 2004, p. 66). The development of a health care plan for the elderly has been directed by a range of principles and concepts that influence it. The World Health Organization (WHO) has also come up with guidelines and policy statements through the WHO Active Ageing Policy Framework that influence the commun ity health care development program. The health care programs aim is to introduce value and new scope to the existing primary health care program by adding integrated social and health services. This will be achieved through a partnership with the public and private health care providers to meet the increasing needs of the elderly. The process of building a comprehensive program for the elderly requires consideration of some overarching facts as a guiding
Wednesday, November 20, 2019
Short paper - Essay Example It can be said beyond doubt that academic education plays an important role in sharpening and broadening the minds of the students, however practical application of the theoretical studies do much more. Providing vocational education in the high schools also diversify the curriculum, providing students with greater learning and experience. If a person wishes to pursue a career in a technical field, he needs to have a solid foundation and practice to ensure a successful career. This foundation can be made if high schools offer optional vocational education to its students. Vocational education also prepares the students for their practical life by granting them exposure to the practical work. If the students get vocational education during their high school, they can also polish their skills by working part time in the related field; so that by the time, their high school is finished, they would be ready to follow their respective careers. Providing vocational education in high school also allows the students to recognize their interests so that, in future they can opt for a career that suits their liking. The market for skilled technical labor is constantly on the rise. Technical workers are hugely in demand and thus get high compensations for their work. For the country to fulfill its technical needs, it requires a greater supply of such labor. Not everyone plans on attending further education in university or college.
Monday, November 18, 2019
Cuban Missile - Essay Example John F. Kennedy was the US president during this time of crisis. He therefore had to make swift moves to avoid going into war with the Soviet Union. As Robert Kennedy and Arthur Jr. Schlesinger portray in their book In Thirteen Days, they applaud John F. Kennedy for the way in which he handled the crisis.KennedyÃ¢â¬â¢s team of Executive Committee of the National Security Council (ExComm) congregated and deliberated on different ways to deal with the crisis. As Robert puts it, they considered several options. The first one was invading Cuba, option two was ordering air strikes with the intention of taking out the missile areas, the other option was imposing a blockade around Cuba. This was aimed at keeping out the undelivered missiles. The fourth option they considered was presenting a private ultimatum to Nikita Khrushchev and in the event that the missiles were not removed, then a military action was to be taken. The fifth and the last option was to present some offer of trade for the missiles in Cuba and those in Turkey.The fifth option was fronted and therefore at the heart of the crisis KennedyÃ¢â¬â¢s administration agreed to withdraw or remove the US missile s from the republic of Turkey and in exchange the Soviet Union was to also remove their nuclear forces from Cuba. The US central concession handled the matter in secret unlike the Soviet who came out in public. The US thought that the idea of withdrawing from the republic of Turkey would have seen the administration that was in place as weak.
Saturday, November 16, 2019
Air Conditioner Using Engine Exhaust Heat This paper describes the development possible in the field of vehicle air conditioning based on vapour absorption cooling. The cooling effect is produced by waste heat energy recovered from engine exhaust. The advantages of such a system are drastic reduction of fuel over consumption and emissions associated with vehicle air conditioner usage. The current air conditioning system used in automobile is based on vapour compression cycle which necessarily consists of a compressor driven by engine output and thus increases fuel consumption rate and pollution proportion. The introduction of vehicle air conditioning using vapour absorption cycle eliminates the need for compressor; here compressor is replaced by generator and absorber unit. Engine waste heat from exhaust gases is used as heat source for generator of vapour absorption system. This paper describes the development possible in the field of vehicle air conditioning based on vapour absorption cooling. Some limitations are outlined and suggestions for future improvement are pointed out. Keywords Vapour Absorption Refrigeration Cycle, Vapour Compression Refrigeration Cycle. Introduction Motivating factors for the designing this system is continuous optimization of the performance of internal combustion engines and the increasing utilization of air conditioning in vehicles, as it reaches the status of essential need for modern life. Internal combustion engines are potential energy sources for absorption refrigeration systems, as about one third of the energy availability in the combustion processes wasted through the exhaust gas. Thus, use of the exhaust gas in an absorption refrigeration system can increase the overall system efficiency. An automobile engine utilizes only about 35% of available energy and rests are lost to cooling and exhaust system. If one is adding conventional air conditioning system to automobile, it further utilizes about 5% of the total energy. Therefore automobile becomes costlier, uneconomical and less efficient. It also decreases the life of engine and increases the fuel consumption. For very small cars compressor needs 3 to 4 bhp, a significant ratio of the power output. Keeping these problems in mind, a car air conditioning system is proposed from recovery of engine waste heat using engine exhaust as source of generator for VARS. Introduction to VARS: Figure 1 Schematics of Ammonia Water Absorption Refrigeration System Fig. 1 shows a schematic of the basic aqua-ammonia refrigeration cycle. High pressure ammonia vapor enters the condenser, where it transfers heat to the neighborhood. Liquid ammonia leaves the condenser and passes through an expansion valve, reaching the evaporator pressure. The refrigerant then enters the evaporator, where it receives heat from the cold source, turning into low pressure vapor. In the sequence, ammonia vapor enters the absorber, where a weak solution of water and low concentration ammonia absorbs the refrigerant and, at the same time, transfers heat to the neighborhood. The solution has now a high ammonia concentration, and is pumped to the vapor generator, where it receives heat from an external source. The ammonia in the solution then evaporates, separating from water and flowing to the condenser to start a new cycle. A weak water-ammonia solution leaves the vapor generator and enters the absorber to absorb ammonia vapor from the evaporator. A heat exchanger betwee n the absorber and the vapor generator transfers heat from the weak solution leaving the vapor generator to the high ammonia concentration solution going into the vapor generator. The coefficient of performance (COP) of the absorption system is usually much lower in magnitude then the compression system. But this low value of the former is not of much importance since it uses the waste heat such as engine exhaust heat. The most important thing about VARS is even if the evaporator temperature falls, the same COP can be maintained by elevating the generator temperature .Hence the capacity of the system remains almost the same. Design procedure of heat extraction device: Since VARS is heat operated cycle we need heat extraction device to extract heat from high temperature source and to deliver this heat to the generator of system. In order to enhance the performance of the refrigeration cycle we need to optimize the design of the Heat Extraction device. Because of its simplicity in operation, less installation as well as maintenance cost, we select Heat Exchanger as heat extraction device. C:UsersLENOVODesktopA4heatex.jpg Figure2- Schematic of Heat Exchanger In order to find the dimensions of the Heat Exchanger we have to assume certain cooling capacity of the cooling system. Lets assume it as 2.5 kW that is Qref = 2.5 kW. Calculations for Heat Extraction Device that is in our case a Heat Exchanger are as follows Calculation for Ammonia site: Calculation of mass flow rate Qref = Ã ¡Ã ¹Ã *cp*(Tg Te ) (1) Where , cp specific heat capacity Tg Temperature of the generator Te Temperature of evaporator Ã ¡Ã ¹Ã Mass flow rate From this equation we can determine mass flow rate of refrigerant. Calculation of velocity Ã ¡Ã ¹Ã =A*v*Ã Ã (2) Where, Ã Ã = density of the refrigerant (taken from design data book) A Flow Area for Refrigerant Ammonia In order to find A we have to take diameter of the tube according to availability in the market. v is the velocity of the refrigerant . Calculation of Reynolds number Re = (Ã Ã *v*D)/Ã µ (3) Where D = diameter of the refrigerant tube Ã µ = dynamic viscosity of refrigerant at mean temperature (taken from design data book) Calculation of Prandtl number Pr = (Ã µ*Cp)/ k (4) Where, Cp = specific heat of the refrigerant k = thermal conductivity of the refrigerant Calculation of Nusselt number Calculation of the Nusselt number is based on the co-relations and the selection of the co-relation is based on the magnitude of the Re ,Pr , and the nature of the heat transfer surface. In our particular condition we select Gnielinski co-relation, since it involves less uncertainty (6%) so mathematical result will be more accurate. Nu = ((Ãâ Ã¢â¬â¢/2)* (Re 1000)*Pr)/ (1+12.7* (Ãâ Ã¢â¬â¢/2)1/2*((Pr)2/3 1)) (5) Where, Ãâ Ã¢â¬â¢ = friction factor its value depends on the Re Ãâ Ã¢â¬â¢= 0.079(Re)-0.25 4*103 Ãâ Ã¢â¬â¢=0.046(Re)-0.2 3*104 Calculation of convective heat transfer co-efficient Nu = (hr*D)/k (8) Where, hr = Convective heat transfer co-efficient k = Thermal conductivity of the ammonia Similar way we can find out these parameters for exhaust gases by following the same procedure. Calculation of Log Mean Temperature Difference (LMTD) Ã ¢Ãâ Ã¢â¬ Tm = (Ã ¢Ãâ Ã¢â¬ T1-Ã ¢Ãâ Ã¢â¬ T2) / ln(Ã ¢Ãâ Ã¢â¬ T1/Ã ¢Ãâ Ã¢â¬ T2) (9) Where, Ã ¢Ãâ Ã¢â¬ T1 = Temperature difference between the exhaust inlet temperature and refrigerant exit temperature Ã ¢Ãâ Ã¢â¬ T2 = Temperature difference between exhaust outlet temperature and refrigerant inlet temperature Calculation of Total Thermal Resistance Qref =U*A *Ã ¢Ãâ Ã¢â¬ Tm (10) Since Ã ¢Ãâ Ã¢â¬ Tm / Qref is the total thermal resistance we will get the value of 1/ U*A Calculation of the length of heat exchanger Rtotal = Rconv.+Rcond.+Rconv. (11) 1/(U*A)= 1/(he*A) + (ln( ro/ri)) /(2Ã Ã¢â ¬*L*k) + 1/(href*A) (12) Where, he = Convective heat transfer coefficient of the exhaust gasses href = Convective heat transfer coefficient of the refrigerant A = Heat Transfer Area From equation (12) we can easily calculate optimum value of the length of heat exchanger. Now Effectiveness of Heat Exchanger changes as Inlet Temperature Difference between hot exhaust gases and cool refrigerant varies. Effectiveness of Heat exchanger can be calculated by following procedure. Calculation of the effectiveness of the heat exchanger In case of the counter flow the effectiveness Ãâ°Ã¢â¬ º is given by Ãâ°Ã¢â¬ º = (1-EXP((-1+C)*NTU) /(1- C* EXP( (-1-C)*NTU)) (13) Where, NTU = Number of Transfer Unit NTU = (U*A)/(Ã ¡Ã ¹Ã * CP)min. (14) C = Capacity Ratio C = (Ã ¡Ã ¹Ã * CP)min / (Ã ¡Ã ¹Ã * CP)max (15) Calculation of amount of heat transfer to the generator Ãâ°Ã¢â¬ º = (actual heat transfer / maximum heat transfer) (16) Maximum heat transfer Qmax = Ã ¡Ã ¹Ã *CP*Ã ¢Ãâ Ã¢â¬ Tmax (17) Where, Ã ¢Ãâ Ã¢â¬ Tmax = Maximum temperature difference between hot exhaust gases and cold refrigerant Using Equations (14) (15) we can calculate actual heat transferred to the generator of the VARS. Calculation of Coefficient of Performance (COP) of VARS COP= (Cooling Effect Produced / Heat Energy Input to Generator) (18) Since COP is the function of temperature we can calculate the COP by using following relation also, COP= (Te*(Tg-Ta))/ (Tg*(Ta-Te)) (19) Where Te = Temperature of the evaporator Tg = Temperature of the generator Ta = Temperature of absorber Results and Discussion: For optimization of design of heat extraction device, we need to determine and fix some parameters. Assume desired heat transfer to be 3 kW. Also we need to find out the specific temperature or temperature range of VARS generator so as to have optimum COP. Graph 1: Generator Temperature Vs COP of VARS From graph 1, it is clear that VARS system will have maximum COP in the generator temperature range of 118Ã °c (391 K) to 127Ã °c (400 K). Now we can fix the refrigerant outlet temperature. Furthermore we cannot reduce the exhaust gas temperature below certain level. Sudden drop in exhaust temperature will cause the exhaust gas to slow down. The drop in exhaust temperature can be accommodated by reducing the exhaust pipe diameter. After fixing the generator temperature i.e. , refrigerant outlet temperature, exhaust gas outlet temperature and refrigerant inlet temperature, the only parameter remaining is exhaust gas inlet temperature. Exhaust temperature varies with load conditions (no load to full load conditions) and driving conditions (idling to power mode). This results in to change in LMTD, due to which the overall heat transferred to refrigerant changes. As a result of change in exhaust gas inlet temperature the effectiveness of heat exchanger changes. As exhaust temperature increases effective heat transfer area required decreases as well as effectiveness of heat exchanger reduces. Optimum heat transfer area and effectiveness of heat exchanger is represented by graph 2. Graph 2: Optimum Heat Transfer Area, Effectiveness Vs Inlet Temperature Difference Effectiveness is the function of temperature difference between hot exhaust gases and cold refrigerant at inlet. As this temperature difference increases, effectiveness of heat exchanger decreases. Effectiveness of heat exchanger is not of prime concern. We can maintain the effectiveness to certain level by varying refrigerant inlet temperature by some means, for example, electric heating. It will maintain the temperature difference between two fluids at inlet. Small amount of energy will be utilized to elevate the refrigerant temperature. Prime concern of the study is to obtain desired cooling effect by utilizing exhaust waste heat. So effectiveness of heat exchanger can be compromised to certain level. Practically, COP of system will be much lower as compared to mathematically obtained values but sufficient to produce desired cooling effect efficiently. Graph 1 represents the theoretical values of COP obtained by equation (19). We have used these values to determine optimum generator temperature. After fixing the parameters of heat extraction device (Heat Exchanger), the practical values of COP are obtained by using equation (18). Graph 3 represents the practical values of COP. It is clear from graph 3 that as generator temperature rises from 118Ã °c to 127Ã °c, COP values drops to 73% and cooling effect obtained at a point is 2.8 kW and effectiveness of heat exchanger is about 50%. Graph 3: Generator Temperature Vs COP Conclusion From the above results we can say that it is possible to extract waste heat of the engine exhaust using heat exchanger. In order to increase the performance of VARS we have to operate heat exchanger at the optimum condition mentions in results. Some precaution we have to take care such as at the initial stages of engine operation performance of VARS is low, hence to get the same cooling effect we have heat ammonia generator using heating coil.
Wednesday, November 13, 2019
Demand Management and Fiscal Policy Fiscal policy is the manipulation of aggregate demand using taxation and or government spending. The government tends to make most of its fiscal decisions in the annual budget, usually announced in March of each year. However, there are a number of problems in using fiscal policy to control aggregate demand - one of the most significant is the problem of time-lags. 1. Time Lags Many aspects of fiscal policy have a delayed effect on aggregate demand. Changing the fiscal stance can take some time to achieve. For example switching to an expansionary fiscal policy through increased government spending can take some time before the full multiplied effects are felt on the economy. If the government announced increased health service spending, there could be considerable delays, as various committees decide how best to allocate the new funding. Then, if some extra construction work is planned, contracts need negotiating and awarding, all before actual spending takes place. On top of all these delays, major capital projects such as new hospital extensions could themselves take some time to complete. The net effect is that there may be months if not years before the planned increased in government spending actually has its full effect on the economy. This scenario is equally appropriate if the government is intending to build more roads, employ more teachers, invest more in the military etc. Admittedly, a tax change is probably quicker to introduce, although often businesses need some advanced warning so they can accommodate any change - again building-in some delay. Question: So what is his the problem of this for demand management ? The danger is that if the government was attempting to reflate the economy ( ie boost AD ) because of a lack of demand and economic activity, by the time the expansionary fiscal policy takes effect - the economy could have entered an upswing. Thus the economy might end up being stimulated at exactly the most inappropriate time. This time lag in fiscal policy could lead to exaggerated swings in the trade cycle - increasing volatility and hence inducing more uncertainty. 2. Fine Tuning -------------- Fine tuning is difficult when using fiscal policy. This refers to the ability to manipulate taxes and spending plans to bring abo... ...there any benefits ? Alternatively, an interest rate decrease is likely to lead to some capital outflows and hence a weakening of the currency. 2. Interest rates and time lags There can be some delays before the full effects of interest rates change are felt on the economy. When the Bank of England push up rates for example, it will take some time for the full effects to filter through the economy. Some estimates put this delay as being as long as 18 months. This is because, some banks eg HSBC, NatWest may not immediately adjust their rates straight away. Even if they do, some individuals may have fixed rate loans or mortgages, or they have some period of fixed rate ( eg for the first 3 years of a mortgage). Therefore, these individuals will not have their discretionary income changed for some time. Individuals with outstanding amounts on credit cards may also benefit from a couple of months delay before they start to notice that their interest payments have started to rise. Nevertheless, interest rate changes are thought to be much faster acting that fiscal policy changes, as at least an interest change will have some immediate impact straight away.