Termodynamik og varme

This book presents a summary of high-pressure phase transitions of minerals and related inorganic compounds. The first part reviews the methods to investigate phase transitions by direct high-pressure and high-temperature experiments together with thermodynamic approaches that consist of calorimetric measurements and thermodynamic calculation. In the second part, phase relations and thermodynamic properties of olivine, pyroxene, garnet, spinel, perovskite, rutile, and related inorganic compounds with A2BO4, ABO3, AB2O4, and AO2 stoichiometries are described. Particular emphasis is placed on spinel- and perovskite-structured phases and their high-pressure polymorphs called post-spinel and post-perovskite phases. The last part of the book focuses on phase relations of mantle rocks and on natural high-pressure minerals from the Earth's deep mantle and in shocked meteorites.  

Für alle, die fasziniert vom Fliegen sind und ein tieferes Verständnis dafür entwickeln wollen, wie Vögel und Modellflugzeuge ihre Kreise in der Luft ziehen. Anschaulich und unterhaltsam führt der Autor in die komplexen Sachverhalte von Wirbel, Zirkulation und Auftrieb ein. Verständlich und begreifbar durch zahlreiche Diagramme und Videos. Es gelingt dem Autor die dem dynamischen Auftrieb zugrunde liegenden Gesetzmäßigkeiten besonders anschaulich darzustellen.

The thesis presents a systematic study of the Mpemba effect in a colloidal system with a micron-sized particle diffusing in a water bath. While the Mpemba effect, where a system's thermal relaxation time is a non-monotonic function of the initial temperature, has been observed in water since Aristotle's era, the underlying mechanism of the effect is still unknown. Recent studies indicate that the effect is not limited to water and has been studied both experimentally and numerically in a wide variety of systems. By carefully designing a double-well potential using feedback-based optical tweezers, the author demonstrates that an initially hot system can sometimes cool faster than an initially warm system. The author also presents the first observation in any system of another counterintuitive effect-the inverse Mpemba effect-where the colder of the two samples reaches the thermal equilibrium at a hot temperature first. The results for both the observations agree with theoretical predictions based on the Fokker-Planck equation. The experiments reveal that, for carefully chosen conditions, a strong version of both of the effects are observed where a system can relax to the bath temperature exponentially faster than under typical conditions.

"Introducing the state-of-the-art of hypervelocity shock tunnels, this complete reference features a variety of drivers and step-by-step introductions to their theories, physics, methods and testing. This book enables researchers and engineers in aerospace to design and improve wind tunnels that simulate flow qualities of real hypersonic flyers"--

This book gives an insight into the current developments in the field of continuum mechanics. Twenty-five researchers present new theoretical concepts, e.g., better inclusion of the microstructure in the models describing material behavior. At the same time, there are also more applications for the theories in engineering practice.In addition to new theoretical approaches in continuum mechanics and applications, the book puts an emphasis on discussing multi-physics problems.

Die phänomenologische Thermodynamik ist von wenigen grundlegenden Observablen, Konzepten, und Zusammenhängen bestimmt, die nicht einfach zu vermitteln sind, besonders dann, wenn die notwendige mathematische Vorstellung und Fähigkeit der Studierenden an Grenzen stößt. Das vorliegende Lehr- und Übungsbuch "Chemische Thermodynamik" vermittelt Studierenden im Haupt- und Nebenfach Chemie anschaulich polytrope Zustandsänderungen, Reaktions- und Phasengleichgewichte, Oberflächen und Grenzflächen sowie Verfahren und Vergleich von herkömmlicher und moderner Energiegewinnung und Bioenergetik. Ideal zur Prüfungsvorbereitung sind die rund 500 explizit gelösten Fragen und Aufgaben, u.a. zu idealen und realen Gasen, zur Bioenergetik etc., und der lerndidaktisch förderliche Anspruch auf Parallelität von prägnanter Fassung der Theorie und extensiver fächerintegrierender Übung. Neu in der 4., umfassend überarbeiteten und ergänzten Auflage: - Zusätzliche Kapitel zu schadstofffreien Emissionen, thermischer Analyse und Umwandlungsketten von grünem Wasserstoff als klimaneutraler Brennstoff der deutschen Energiewende. - Zusätzliche Übungsaufgaben und Lösungen. - Optimal zur Prüfungsvorbereitung und darüber hinaus.

The 155-C A/B/C heat exchangers, belonging to an olefins plant, which heat the water used in reboilers of some fractionation columns, have historically presented energy efficiency problems due to fouling by polymerization in the tubes, the side through which the process water passes. This was used as a basis for simulating different mechanical models in Aspen EDR, taking into account the fouling problem in the conceptual design criteria. The book contains a brief description of the plant process, with emphasis on the system to which the equipment in question belongs; a summary of the basic theoretical fundamentals of shell and tube heat exchanger design; and an introduction to the Aspen Exchanger Design & Rating simulation interface. The original design data, conceptual design criteria, simulation results and procedure are detailed.

Thermodynamics is a branch of physics that studies the relationship between heat, work, temperature and energy, entropy, radiation and the physical properties of matter. It majorly focuses on the transfer of energy from one form to another and from one place to another. Thermodynamics is principally based on a set of four laws that govern the behavior of physical quantities such as heat, work, temperature and energy. The two properties of thermodynamics include enthalpy and entropy, which may be extensive or intensive. Enthalpy is defined as measurement of energy in a thermodynamic system. Entropy is a thermodynamic function that measures the randomness or disorder. These properties are capable of specifying the state of the system. Thermodynamics is applied in various fields such as physical chemistry, biochemistry, chemical engineering and mechanical engineering. This book is compiled in such a manner, that it will provide an in-depth knowledge about the subject of thermodynamics. It will serve as a valuable source of reference for graduate and postgraduate students.

Fluid flow refers to the motion of a fluid under the influence of various unbalanced forces. It primarily belongs to a branch of fluid mechanics that is typically concerned with the dynamics of fluids. Heat transfer is a field of thermal engineering that focuses on the consumption, exchange, generation and conversion of thermal energy among physical systems. It is divided into several mechanisms, including thermal radiation, thermal conduction, thermal convection and transmission of energy through phase changes. Fluid flow and heat transfer are critical components of engineering process design. Heat transfer into a fluid leads to the development of an equilibrium temperature under constant flow, which requires the solution of the Navier-Stokes equations. This book includes some of the vital pieces of works being conducted across the world on fluid flow and heat transfer. It will also provide interesting topics for research, which interested readers can take up. This book is a resource guide for experts as well as students.

Thermal engineering refers to a sub-discipline of mechanical engineering concerned with the transmission and movement of heat energy. This energy can be converted into different types of energy. Thermal engineering is used in a variety of industries including the construction industry, heating ventilation and cooling industry, and automotive industry. Concepts related to mass transfer, heat transfer, thermodynamics and fluid mechanics may be used to solve thermal engineering problems. There are various applications of thermal engineering including process fired heaters, thermal power plants, combustion engines, compressed air systems, thermal insulation, boiler design, refrigeration systems, and heat exchangers. This book outlines the concepts and applications of thermal engineering in detail. It is a valuable compilation of topics, ranging from the basic to the most complex advancements in this field. This book will serve as a reference to a broad spectrum of readers.

Fluid flow and heat transfer processes play a significant role in various fields of engineering and science from microscopic to the planetary scale. Heat transfer can be improved by using nanofluids. The problem with fluid flow occurs because of a continuously moving surface in an ambient fluid, which differs from the fluid that flows past a fixed surface. Fluid flow problems in the absence of chemical reactions and electromagnetic forces involve thermal and mechanical variables only. There are three methods or techniques that are utilized to address problems in fluid mechanics and heat transfer, namely, numerical methods, experimental methods, and theoretical methods. This book aims to shed light on the science and engineering of fluid flow and heat transfer. It consists of contributions made by international experts. This book will serve as a reference to a broad spectrum of readers.

Thermodynamics is a branch of physics that deals with matter and conversion of energy. Engineering thermodynamics is a subject of mechanical engineering that involves applying the principles of thermodynamics to engineering design of processes, devices, and systems, which involve effective utilization of energy and matter. Conversion between heat and work is fundamental in engineering thermodynamics. Entropy refers to a measurable physical characteristic and a scientific concept that is connected to a state of uncertainty, unpredictability or disorder. It is utilized in a variety of fields, including the principles of information theory, classical thermodynamics, and the microscopic description of nature in statistical physics. Entropy is central to the second law of thermodynamics, which asserts that the entropy of isolated systems left to unstructured expansion cannot decrease over time. This is due to the isolated systems always reaching thermodynamic equilibrium with the highest entropy. Different scenarios involving entropy production such as optimizing power and waste heat reduction can be studied by taking the help of simulation tools. This book aims to shed light on some of the unexplored aspects of engineering thermodynamics and the latest researches on simulation with entropy. It will serve as a valuable source of reference for graduate and postgraduate students.

An internal combustion engine (IC engine) refers to a type of heat engine wherein the combustion of fuel occurs with the help of an oxidizer in the combustion chamber, which is a significant part of the working fluid circuit. The expansion of the high-pressure and high-temperature gases generated through combustion puts direct force on certain components of an IC engine. Usually, the force is applied to turbine blades, pistons, a nozzle, or a rotor. The component is moved across a distance by this force, which converts chemical energy into kinetic energy, which is further utilized to propel, power or move whatsoever the engine is coupled with. This book is compiled in such a manner, that it will provide an in-depth knowledge about the theory and working of the internal combustion engine. The various advancements in these engines are glanced at and their applications as well as ramifications are looked at in detail. Those in search of information to further their knowledge will be greatly assisted by this book.

Heat transfer refers to a branch of thermal engineering which deals with the conversion, generation, exchange and utilization of thermal energy within physical systems. There are several mechanisms of heat transfer including thermal radiation, heat conduction and heat convection. There are various examples of heat transfer, such as greenhouse effect, refrigeration and maintenance of optimum temperature within the human body. Heat-transfer principles can be employed for maintaining, decreasing or increasing temperature in a variety of situations. It has numerous applications in industries such as milk pasteurization, temperature control for purified water, laser cooling, night vision cameras, and magnetic cooling. Many disciplines utilize heat transfer methods including materials processing, automotive engineering, power station engineering, insulation, chemical engineering and climate control. This book outlines the processes and applications of heat transfer in detail. It will provide comprehensive knowledge to the readers.

Heat transfer refers to a field of thermal engineering that deals with the generation, use, conversion and exchange of heat (thermal energy) among physical systems. It is achieved through several mechanisms including thermal radiation, thermal conduction, thermal convection, and transfer of energy through phase changes. Mass transfer refers to the net transfer of mass from one location to another. It is achieved through a variety of processes such as evaporation, precipitation, absorption, distillation, drying and membrane filtration. The heat and mass transfer processes are the foundation of energy research applicable to boilers, gas turbines, fuel cells and solar power. Power and fluid machinery, multiphase flow, thermodynamics, and combustion are the main processes involved in the heat and mass transfer process. This book explores all the important aspects of heat and mass transfer in energy systems. It consists of contributions made by international experts. This book will serve as a reference to a broad spectrum of readers.

Heat transfer refers to the movement of heat across the border of a system caused due to difference between the temperature of the system and its surroundings. Mass transfer refers to the physical phenomenon that involves the observation of a net movement of generic particles from one place to another. These phenomena are the basis of various mechanisms and processes such as distillation of alcohol, the evaporation of water, and purification of blood in the liver and kidneys. Heat and mass transfer is a significant and well-established branch of engineering and physics. It also finds application in multiple manufacturing procedures. This book aims to shed light on the role of heat and mass transfer in the energy systems. It will also provide interesting topics for research, which interested readers can take up. With state-of-the-art inputs by acclaimed experts of this field, this book targets students and professionals.

This book compiles historical notes and a review of the work of the author and his associates on shock compression of condensed matter (SCCM). The work includes such topics as foundational aspects of SCCM, thermodynamics, thermodynamics of defects, and plasticity as they relate to shock compression, shock-induced phase transition, and shock compaction. Also included are synthesis of refractory and hard ceramic compounds such as Ni aluminides, SiC and diamonds, method of characteristics, discrete element methods, the shock compression process at the grain scale, and modeling shock-to-detonation transition in high explosives.The book tells the story of how the author's view of shock physics came to be where it is now. and analytically discusses how the author's appreciation of shock waves has evolved in time. It offers a personal but pedagogical perspective on SCCM for young scientists and engineers who are starting their careers in the field. For experts it offers materials to nudge them reflect on their own stories, with the hope of planting a seed of motivation to write them down to be published.

Nanotechnology for Hydrogen Production and Storage: Nanostructured Materials and Interfaces presents an evaluation of the various nano-based systems for hydrogen generation and storage. With a focus on challenges and recent developments, the book analyzes nanomaterials with the potential to boost hydrogen production and improve storage. It assesses the potential improvements to industrially important hydrogen production technologies by way of better surface-interface control through nanostructures of strategical composites of metal oxides, metal chalcogenides, plasmonic metals, conducting polymers, carbonaceous materials, and bio-interfaces with different types of algae and bacteria.In addition, the efficiency of various photochemical water splitting processes to generate renewable hydrogen energy are reviewed, with a focus on natural water splitting via photosynthesis, and the use of various metallic and non-metallic nanomaterials in anthropogenic/artificial water splitting processes is analyzed. Finally, the potential of nanomaterials in enhancing hydrogen generation in dark- and photo-fermentative organisms is explored, along with various nano-based systems for hydrogen generation and associated significant challenges and advances in biohydrogen research and development.