Surendra Singh Yadav

La corretta dissipazione dell'energia termica da un sistema sempre un requisito per molte apparecchiature e industrie. Qualsiasi dispositivo che funziona utilizzando una fonte di alimentazione esterna genera sempre calore. Il calore generato in questi sistemi deve essere espulso nell'ambiente circostante. La massimizzazione della superficie dei dispositivi in genere aumenta il tasso di raffreddamento. Tuttavia, rende il sistema ingombrante. Pertanto, un corretto utilizzo della superficie del sistema un parametro importante per avere un sistema di dissipazione del calore efficiente. sempre stato auspicabile avere un dissipatore di calore in tutti i dispositivi che occupi il minimo spazio con la massima efficacia. Il presente lavoro analizza la fisica del trasferimento di calore coniugato in un sistema tridimensionale di pinne in alluminio, con l'aria come fluido di lavoro. stato utilizzato un solutore di volume finito, ANSYS Fluent, per simulare una disposizione sfalsata di alette a spillo su una piastra di base. Il solutore stato convalidato utilizzando i dati sperimentali. L'analisi termica stata eseguita su alette con diverse sezioni trasversali. Sono state prese in considerazione alette con sezioni trasversali circolari, esagonali, pentagonali, triangolari e a forma di goccia con varie velocit di ingresso.

Die ordnungsgem e Ableitung von W rmeenergie aus einem System ist f r viele Ger te und Industrien immer eine Voraussetzung. Jedes Ger t, das mit einer externen Stromquelle betrieben wird, erzeugt immer W rme. Die in solchen Systemen erzeugte W rme muss an die Umgebung abgef hrt werden. Eine Maximierung der Oberfl che der Ger te verbessert im Allgemeinen die K hlleistung. Allerdings wird das System dadurch auch unhandlich. Daher ist eine gute Ausnutzung der Oberfl che des Systems ein wichtiger Parameter f r ein effizientes W rmeableitungssystem. Es war immer w nschenswert, einen K hlk rper in allen Ger ten zu haben, der ein Minimum an Platz bei maximaler Effektivit t einnimmt. In der vorliegenden Arbeit wird die Physik der konjugierten W rme bertragung in einem 3-D-System aus Aluminium-Stiftlamellen mit Luft als Arbeitsmedium analysiert. Ein Finite-Volumen-Solver, ANSYS Fluent, wurde f r die Simulation einer gestaffelten Stiftflossenanordnung auf einer Grundplatte verwendet. Der Solver wurde anhand der experimentellen Daten validiert. Die thermische Analyse wurde f r Rippen mit verschiedenen Querschnitten durchgef hrt. Es werden Rippen mit kreisf rmigem, sechseckigem, f nfeckigem, dreieckigem und tropfenf rmigem Querschnitt mit verschiedenen Eintrittsgeschwindigkeiten betrachtet.

A dissipa o adequada da energia t rmica de um sistema sempre um requisito para muitos equipamentos e ind strias. Qualquer dispositivo que funcione com uma fonte de energia externa gera sempre calor. O calor gerado em tais sistemas deve ser expelido para o ambiente circundante. A maximiza o da rea de superf cie dos dispositivos aumenta geralmente a taxa de arrefecimento. No entanto, torna o sistema volumoso. Por conseguinte, a utiliza o correcta da rea de superf cie do sistema um par metro importante para obter um sistema de dissipa o de calor eficiente. Sempre foi desej vel ter um dissipador de calor em todos os dispositivos que ocupasse o m nimo de espa o com a m xima efic cia. O presente trabalho analisa a f sica da transfer ncia de calor conjugada num sistema 3-D de alhetas de alum nio, com ar como fluido de trabalho. Foi utilizado um solucionador de volumes finitos, ANSYS Fluent, para simular um arranjo escalonado de alhetas colocado sobre uma placa de base. O calculador validado utilizando os dados experimentais. A an lise t rmica foi efectuada em alhetas com v rias sec es transversais. S o consideradas as alhetas com sec es transversais circulares, hexagonais, pentagonais, triangulares e em forma de gota com v rias velocidades de entrada.

La dissipation correcte de l' nergie thermique d'un syst me est toujours une exigence pour de nombreux quipements et industries. Tout appareil fonctionnant l'aide d'une source d' nergie externe g n re toujours de la chaleur. La chaleur g n r e dans ces syst mes doit tre vacu e dans l'environnement. La maximisation de la surface des appareils am liore g n ralement le taux de refroidissement. Cependant, cela rend le syst me encombrant. Par cons quent, une bonne utilisation de la surface du syst me est un param tre important pour disposer d'un syst me de dissipation thermique efficace. Il a toujours t souhaitable d'avoir un dissipateur de chaleur dans tous les dispositifs qui occupent un minimum d'espace avec un maximum d'efficacit . Le pr sent travail analyse la physique du transfert de chaleur conjugu dans un syst me tridimensionnel d'ailettes en aluminium, avec de l'air comme fluide de travail. Un solveur de volumes finis, ANSYS Fluent, a t utilis pour simuler un arrangement d'ailettes en quinconce plac sur une plaque de base. Le solveur est valid l'aide des donn es exp rimentales. L'analyse thermique a t r alis e sur des ailettes de diff rentes sections. Les sections transversales des ailettes sont circulaires, hexagonales, pentagonales, triangulaires et en forme de goutte d'eau, avec diff rentes vitesses d'entr e.

Proper dissipation of thermal energy from a system is always a requirement for many equipment and industries. Any device that runs using external power source always generates heat. The generated heat in such systems must be expelled to the surrounding. Maximizing the surface area of the devices generally enhances the cooling rate. However, it makes the system bulky. Therefore, a proper utilization of the surface area of the system is an important parameter to have an efficient heat dissipation system. It was always desirable to have a heat sink in the all devices that occupy minimum space with maximum effectiveness. The present work analyse conjugate heat transfer physics in a 3-D system of aluminium pin fins, with air as the working fluid. A finite volume solver, ANSYS Fluent has been used in simulating a staggered pin fin arrangement placed over a base plate. The solver is validated using the experimental data. The thermal analysis has been performed on fins with various cross sections. Consideration is given to fins having circular, hexagonal, pentagonal, triangular and drop-shaped cross sections with various inlet velocities.

O polimento um processo de trabalho a frio em que a deforma o pl stica ocorre por meio de press o aplicada atrav s de uma esfera ou rolo de metal muito duro e liso. A aplica o de processos de polimento pode melhorar o acabamento da superf cie, o limite de elasticidade, a resist ncia fadiga, a resist ncia ao desgaste, a dureza da superf cie, a resist ncia tra o e a resist ncia corros o. Como neste processo n o h remo o do material extra da superf cie de uma pe a de trabalho, o polimento um processo de acabamento sem aparas.

Le brunissage est un processus d'usinage froid dans lequel la d formation plastique se produit au moyen d'une pression appliqu e par l'interm diaire d'une bille ou d'un rouleau en m tal tr s dur et lisse. L'application des proc d s de brunissage peut am liorer la finition de la surface, la limite d' lasticit , la r sistance la fatigue, la r sistance l'usure, la duret de la surface, la r sistance la traction et la r sistance la corrosion. Comme dans ce processus, il n'y a pas d'enl vement de mati re suppl mentaire de la surface d'une pi ce, le brunissage est un processus de finition sans copeaux.

Br nieren ist ein Kaltverformungsverfahren, bei dem eine sehr harte und glatte Metallkugel oder -rolle durch Druck plastisch verformt wird. Durch die Anwendung von Br nierverfahren k nnen Oberfl cheng te, Streckgrenze, Erm dungsfestigkeit, Verschlei festigkeit, Oberfl chenh rte, Zugfestigkeit und Korrosionsbest ndigkeit verbessert werden. Da bei diesem Verfahren kein zus tzliches Material von der Oberfl che eines Werkst cks entfernt wird, ist das Br nieren ein spanloses Endbearbeitungsverfahren.

La brunitura un processo di lavorazione a freddo in cui si verifica una deformazione plastica per mezzo di una pressione applicata attraverso una sfera o un rullo metallico molto duro e liscio. L'applicazione dei processi di brunitura pu migliorare la finitura superficiale, il carico di snervamento, la resistenza alla fatica, la resistenza all'usura, la durezza superficiale, la resistenza alla trazione e la resistenza alla corrosione. Poich questo processo non prevede la rimozione del materiale extra dalla superficie del pezzo, la brunitura un processo di finitura senza trucioli.

The book presents a comprehensive view of the Indian equity markets over the past two decades (1994-2014). Equity markets constitute the most important segment of stock exchanges; in fact, the status of equity returns is, by and large, considered as a barometer of the state of a country’s economy. Returns earned by the equity investors on their funds invested in equity markets have become a decisive factor in the growth of such markets. In this context, the book discusses all the major aspects of equity returns and also conducts a dis-aggregative analysis based on underlying factors like age, size, ownership structure, industry affiliation/sector, among others, to explain the factors affecting returns and risk. While on the one hand the study ascertains the market rates of return (earned) on equities from the investors’ perspective (by including both the capital gains and the dividend income), it also shows how to compute the rates of returns on equities from the corporate perspective(that is, rate of return earned on equity funds). It further assesses the required/expected rate of return and examines the volatility in stock returns, with a focus on its behaviour during the period of the study. It deepens investors’ understanding of equity investment, helping them to make more-informed investments. While of interest to the investor community, this book also contributes significantly to the existing literature on market returns and is a valuable reference resource for academics, researchers and market participants, financial institutions and other intermediaries, regulators and policy makers.

The book examines the market reaction to mergers and acquisitions (M&A) announcements over a period from 2003 to 2015. Mergers and acquisitions continue to be amongst the preferred competitive options available to the companies seeking to grow fast in the rapidly changing global business scenario.M&A as a growth strategy has received attention from developed as well as emerging economies. It has been extensively used by managers as an expansion strategy and also serves as an important instrument for increasing corporate efficiency. Recently, M&A has grown at a rapid pace, creating a need for research to analyze what drives this phenomenon and how it affects firms and markets. As such, this book evaluates the impact of M&A on short-term abnormal returns as well long-term financial performance. It also assesses the management view concerning the motives for undertaking M&A. In addition, the book investigates the corporate governance practices of the acquiring firms and their impact on the short- term as well as long- term performance of those firms.

The book examines the market reaction to mergers and acquisitions (M&A) announcements over a period from 2003 to 2015. Mergers and acquisitions continue to be amongst the preferred competitive options available to the companies seeking to grow fast in the rapidly changing global business scenario.M&A as a growth strategy has received attention from developed as well as emerging economies. It has been extensively used by managers as an expansion strategy and also serves as an important instrument for increasing corporate efficiency. Recently, M&A has grown at a rapid pace, creating a need for research to analyze what drives this phenomenon and how it affects firms and markets. As such, this book evaluates the impact of M&A on short-term abnormal returns as well long-term financial performance. It also assesses the management view concerning the motives for undertaking M&A. In addition, the book investigates the corporate governance practices of the acquiring firms and their impact on the short- term as well as long- term performance of those firms.

The book presents a comprehensive view of the Indian equity markets over the past two decades (1994-2014). Equity markets constitute the most important segment of stock exchanges; in fact, the status of equity returns is, by and large, considered as a barometer of the state of a country’s economy. Returns earned by the equity investors on their funds invested in equity markets have become a decisive factor in the growth of such markets. In this context, the book discusses all the major aspects of equity returns and also conducts a dis-aggregative analysis based on underlying factors like age, size, ownership structure, industry affiliation/sector, among others, to explain the factors affecting returns and risk. While on the one hand the study ascertains the market rates of return (earned) on equities from the investors’ perspective (by including both the capital gains and the dividend income), it also shows how to compute the rates of returns on equities from the corporate perspective(that is, rate of return earned on equity funds). It further assesses the required/expected rate of return and examines the volatility in stock returns, with a focus on its behaviour during the period of the study. It deepens investors’ understanding of equity investment, helping them to make more-informed investments. While of interest to the investor community, this book also contributes significantly to the existing literature on market returns and is a valuable reference resource for academics, researchers and market participants, financial institutions and other intermediaries, regulators and policy makers.

Financial management practices are likely to have a marked effect on the financial performance of a corporate enterprise. Therefore, sound financial decisions/practices can contribute towards meeting the desired objective of having profitable operations. This subject assumes paramount significance in view of the present dynamic and turbulent business environment, which has produced more intense competition and smaller profit margins across the world. In this context, the financial management practices of the corporates in India, a country with a vast potential for economic growth, can offer valuable insights.The present study explores whether there has been a major change in the financial performance (measured in terms of profitability) and financial policies/decisions of the sample companies over a fixed period (2000-2001 to 2010-2011), with a special focus on pre and post-recession analysis. It delves deeper into current research areas such as zero working capital, real options in capital budgeting, pecking order in capital structures, and clause 49 as reflected in the financial management decisions of sample companies, and provides a broader perspective by identifying trends (if any) in certain aspects of financial decision-making over the past two decades.A comprehensive study, covering all the major aspects of financial management practices, also contains an inter-sectoral study (among the sample companies) and develops an index of professionalism in financial management based on the practices of the sample companies. The book is primarily targeted at teachers/students of finance, management, commerce, accounting and related professional disciplines/fields. Practitioners/professionals will find it an invaluable text that helps guide them to better decision-making.

Financial management practices are likely to have a marked effect on the financial performance of a corporate enterprise. Therefore, sound financial decisions/practices can contribute towards meeting the desired objective of having profitable operations. This subject assumes paramount significance in view of the present dynamic and turbulent business environment, which has produced more intense competition and smaller profit margins across the world. In this context, the financial management practices of the corporates in India, a country with a vast potential for economic growth, can offer valuable insights.The present study explores whether there has been a major change in the financial performance (measured in terms of profitability) and financial policies/decisions of the sample companies over a fixed period (2000-2001 to 2010-2011), with a special focus on pre and post-recession analysis. It delves deeper into current research areas such as zero working capital, real options in capital budgeting, pecking order in capital structures, and clause 49 as reflected in the financial management decisions of sample companies, and provides a broader perspective by identifying trends (if any) in certain aspects of financial decision-making over the past two decades.A comprehensive study, covering all the major aspects of financial management practices, also contains an inter-sectoral study (among the sample companies) and develops an index of professionalism in financial management based on the practices of the sample companies. The book is primarily targeted at teachers/students of finance, management, commerce, accounting and related professional disciplines/fields. Practitioners/professionals will find it an invaluable text that helps guide them to better decision-making.