Althoughtheprinciplesofoperationofhelicalscrewmachines, ascompressors or expanders, have been well known for more than 100 years, it is only during the past 30 years that these machines have become widely used. The main reasons for the long period before they were adopted were their relatively poor e?ciency and the high cost of manufacturing their rotors. Two main developments led to a solution to these di?culties. The ?rst of these was the introduction of the asymmetric rotor pro?le in 1973. This reduced the bl- hole area, which was the main source of internal leakage by approximately 90%, and thereby raised the thermodynamic e?ciency of these machines, to roughly the same level as that of traditional reciprocating compressors. The second was the introduction of precise thread milling machine tools at - proximately the same time. This made it possible to manufacture items of complex shape, such as the rotors, both accurately and cheaply. From then on, as a result of their ever improving e?ciencies, high rel- bility and compact form, screw compressors have taken an increasing share of the compressor market, especially in the ?elds of compressed air production, and refrigeration and air conditioning, and today, a substantial proportion of compressors manufactured for industry are of this type. Despite, the now wide usage of screw compressors and the publication of many scienti?c papers on their development, only a handful of textbooks have been published to date, which give a rigorous exposition of the principles of their operation and none of these are in English

"Recent Trends in the Condition Monitoring of Transformers" reflects the current interest in replacing traditional techniques used in power transformer condition monitoring with non-invasive measures such as polarization/depolarization current measurement, recovery voltage measurement, frequency domain spectroscopy and frequency response analysis. The book stresses the importance of scrutinizing the condition of transformer insulation which may fail under present day conditions of intensive use with the resulting degradation of dielectric properties causing functional failure of the transformer.

The text shows the reader how to overcome the key challenges facing today s maintenance policies, namely:

The selection of appropriate techniques for dealing with each type of failure process accounting for the needs of plant owners, plant users and wider society; and

Cost-efficiency and durability of effect.

Many of the failure-management methods presented rely on the fact that most failures give warning when they are imminent. These potential failures give rise to identifiable physical conditions and the novel approaches described detect them so that action can be taken to avoid degeneration into full-blown functional failure. This on-condition maintenance means that equipment can be left in service as long as a specified set of performance standards continue to be met, avoiding the costly downtime imposed by routine and perhaps unnecessary maintenance but without risking equally expensive failure.

"Recent Trends in the Condition Monitoring of Transformers" will be of considerable interest to both academic researchers in power systems and to engineers working in the power generation and distribution industry showing how new and more efficient methods of fault diagnosis and condition management can increase transformer efficiency and cut costs."

This book presents a unified hierarchical formulation of theories for three-dimensional continua, two-dimensional shells, one-dimensional rods, and zero-dimensional points. It allows readers with varying backgrounds easy access to fundamental understanding of these powerful Cosserat theories.

This Second Edition continues the fine tradition of its predecessor by exploring the various automatic control systems in aircraft and on board missiles. Considerably expanded and updated, it now includes new or additional material on: the effectiveness of beta-beta feedback as a method of obtaining coordination during turns using the F-15 as the aircraft model; the root locus analysis of a generic acceleration autopilot used in many air-to-air and surface-to-air guided missiles; the guidance systems of the AIM-9L Sidewinder as well as bank-to-turn missiles; various types of guidance, including proportional navigation and line-of-sight and lead-angle command guidance; the coupling of the output of a director fire control system into the autopilot; the analysis of multivariable control systems; and methods for modeling the human pilot, plus the integration of the human pilot into an aircraft flight control system. Also features many new additions to the appendices.

Metals are still the most widely used structural materials in the manufacture of products and structures. Their properties are extremely dependent on the processes they undergo to form the final product. Successful manufacturing therefore depends on a detailed knowledge of the processing of the materials involved. This highly illustrated book provides that knowledge.
Metal processing is a technical subject requiring a quantitative approach. This book illustrates this approach with real case studies derived from industry.
* Real industrial case studies
* Quantitative approach
* Challenging student problems

The book covers the various approaches to modeling the in-cylinder processes such as mixture formation, combustion and formation of exhaust emissions in diesel and gasoline engines. Due to their complexity, emphasis is put on multi-dimensional spray, combustion and emission formation models. However, phenomenological as well as zero-dimensional thermodynamic models, which are still widely used in engine development because of their computational efficiency, are addressed as well. Example calculations of each model type are compared with corresponding experimental data – represented in diagrams as well as in images resulting from modern optical measuring techniques – in order to discuss the capabilities of today's simulation models and the shortcomings that still exist either because of oversimplifying assumptions or insufficient knowledge. Readers achieve an overview of the most important simulation models describing the in-cylinder processes of internal combustion engines and gain insights into which modeling approach is appropriate for a specific problem.

This thesis provides essential information on the systematic design of assembled lanthanide complexes for functional luminescent materials. It discusses the relationships between assembled structures and photo, thermal, and mechanical properties on the basis of crystallography, spectroscopy, and thermodynamics. The described guidelines for assembled structures will be extremely valuable, both for industrial applications and for readers' fundamental understanding of solid-state photophysics and materials chemistry. Luminescent lanthanide complexes are promising candidates for lighting devices, lasers, and bio-probes owing to their line-like and long-lived emission arising from characteristic 4f-4f transitions. Low-vibrational and asymmetrical coordination structures around lanthanide ions have been introduced to achieve strong luminescence, using specific organic ligands. Recently, assembled lanthanide complexes including coordination polymers and metal organic frameworks have increasingly attracted attention as a new class of luminescent materials offering thermal stability and color tunability. However, improving the luminescence efficiencies of these compounds remains a challenge, and specific molecular designs to control assembled structures and yield additional physical properties have not been established. The author provides a group of bent-angled bridging ligands to boost photoluminescence efficiency, and successfully introduces for the first time glass formability and strong triboluminescence properties.

This book discusses the development, types and application principles of portable air purifiers in China. It analyzes the theoretical characteristics of air purifiers under various operational conditions, and points out that the term "Clean Air Delivery Rate" cannot be used to precisely reflect the problems that occur under various operational conditions. By comparing theoretical and measured data, it highlights the mainfeatures of air purifiers and key points in the design process for different applications. Calculation methods for the indoor particle concentration and the self-purification time are also provided. The book describes the conditions for window opening in smog and for selecting air purifiers, and proposes a newmethod for improvingtheir measurement. In closing, it includes a new assessment index.

This is the second volume of a comprehensive two-volume treatment of mechanics intended for students of civil and mechanical engineering. Used for several years in courses at Bradley university, the text presents dynamics in a clear and straightforward way and emphasizes problem solving. More than 350 examples clarify the discussion. The diskette included with the book contains EnSolve, a program written by the authors for solving problems in engineering mechanics. The program runs on Macintosh and PC-DOS computers and includes the following: - a unit converter for SI to US units and vice versa - a graphics program for plotting functions and data - a set of numerical subroutines The graphics module will, among other features, fit smooth splines between data, plot regression lines and curves, and change scales ß including from arithmetic to log and log-log. The numerical routines will, for example, find roots of polynomials, solve systems of equations, invert matrices, differentiate and integrate, and solve boundary-value problems.

This book contains papers presented at the IUTAM/IACM Symposium Discretization Methods in Structural Mechanics II' held in Vienna, Austria, in June 1997. During the last decade the broad field of Discretization Methods in Structural Mechanics' has experienced a remarkable evolution. New aspects have come into focus. Many of them were stimulated by challenging requirements coming from high-tech applications. In these proceedings such recent developments are presented and discussed together with new trends and demands. In view of their relevance, emphasis was put on nonlinear finite element methods and boundary element methods as well as on the coupling of these two numerical methods. Novel developments in other discretization methods having the potential of opening new avenues for promising applications were also considered. The different sources of nonlinearities, such as large deformations, large strains, nonlinear material behaviour (including viscoplasticity, progressive damage, nonlinearities in composites and other microstructured materials), contact with or without friction, etc., require (a) a careful mathematical and mechanical description and modelling, (b) the development of efficient algorithms and (c) a sound computational treatment. Contributions meeting these requirements are presented. Further emphasis was laid on significant improvements concerning efficiency, accuracy and reliability of discretization methods in nonlinear structural mechanics (e.g. error estimation, self-adapting mesh refinement, multigrid methods). A number of papers deal with new aspects of sensitivity analysis and optimization. Neural network strategies as well as modern data processing architectures(such as parallel computers and transputers) and their impact on the developments of new algorithmic concepts are discussed.

This book contains 24 papers presented at the symposium on Recent Advances in Mechanics dedicated to the late Professor Academician Pericles S. Theocaris in commemoration of the tenth anniversary of his death. The papers are written by world renowned and recognized experts in their fields and serve as a reference and guide for future research.

The topics covered in the book can be divided into three major themes: Mathematical methods in applied mechanics (nine papers), experimental mechanics (nine papers) and fracture mechanics (six papers).

Topics covered include: Application of reciprocity relations to laser-based ultrasonics, boundary value problems of the theory of elasticity, optimal design in contact mechanics, scaling of strength and lifetime distributions of quasibrittle structures, directional distortional hardening in plasticity, vibration of systems, instability phenomena in damped systems, variational methods for static and dynamic elasticity problems, an accelerated Newmark scheme for solving the equations of motion in the time domain, photoelastic tomography, electronic speckle pattern interferometry, composites exposed to fire, sampling moire, microelecromechanical systems, experimental mechanics in nano-scale, advanced cement based nanocomposites, piezonuclear transmutations in brittle rocks under mechanical loading, stress triaxiality at crack tips studied by caustics, reinforcement of a cracked elastic plate with defects, some actual problems of fracture mechanics, cyclic plasticity with applications to extremely low cycle fatigue of structural steel, and fracture of a highly filled polymer composite.

Microsystems are an important success factor in the automobile industry. In order to fulfil the customers' requests for safety convenience and vehicle economy, and to satisfy environmental requirements, microsystems are becoming indispensable. Thus a large number of microsystem applications came into the discussion. With the international conference AMAA 2000, VDI/VDE-IT provides a platform for the discussion of all MST relevant components for automotive applications. The conference proceedings gather the papers by authors from automobile suppliers and manufacturers.

The integration of manufacturing constraints and their optImIzation within the design process of mechanical products and systems are now an industrial priority. Following the first two IDMME conferences in Nantes in 1996 and Compiegne in 1998, the purpose of the IDMME'2000 conference was to present recent developments in these areas and new areas within the product and process development theme. The original initiative of the conference is mainly due to the efforts of the French AIP-PRIMECA group (Pool of Computer Resources for Mechanics). The organizing committee and the local organizing institutions (Concordia University, Ecole Poly technique de Montreal, and McGill University) contributed to the success of the conference. The presentation of 190 papers and the presence of more than 225 researchers coming from more than 20 countries demonstrate the success of the initiative. This book contains 57 of these papers selected by an International Scientific Committee: Chairman: C. Fortin (Canada) Co-chairmen: P. Chedmail (France), G. Cognet (France), C. Mascle (Canada), J. Pegna (Canada) J. Angeles (Canada) P. Martin (France) J. L. Batoz (France) C. McMahon (U. K. ) J. C. Bocquet (France) M. Mantyla (Finland) A. - Bernard (France) J. L. Maxwell (USA) P. Bourdet (France) N. M. Patrikalakis (USA) A Clement (France) J. P. Pelle (France) D. Cochran (USA) B. Peseux (France) D. Coutellier (France) D. Play (France) A- Dalsky (Russia) M. Pratt (USA) D. A. Dornfeld (USA) B. Ravani (USA) D. Deneux (France) A. Riviere (France) G. Gogu (France) C.

This book focuses on the mechanisms and underlying mechanics of failure in various classes of materials such as metallic, ceramic, polymeric, composite and bio-material. Topics include tensile and compressive fracture, crack initiation and growth, fatigue and creep rupture in metallic materials, matrix cracking and delamination and environmental degradation in polymeric composites, failure of bio-materials such as prosthetic heart valves and prosthetic hip joints, failure of ceramics and ceramic matrix composites, failure of metallic matrix composites, static and dynamic buckling failure, dynamic excitations and creep buckling failure in structural systems. Chapters are devoted to failure mechanisms that are characteristic of each of the materials. The work also provides the basic elements of fracture mechanics and studies in detail several niche topics such as the effects of toughness gradients, variable amplitude loading effects in fatigue, small fatigue cracks, and creep induced brittleness. Furthermore, the book reviews a large number of experimental results on these failure mechanisms. The book will benefit structural and materials engineers and researchers seeking a "birds-eye" view of possible failure mechanisms in structures along with the associated failure and structural mechanics.

The design of nonlinear controllers for mechanical systems has been an ex tremely active area of research in the last two decades. From a theoretical point of view, this attention can be attributed to their interesting dynamic behavior, which makes them suitable benchmarks for nonlinear control the oreticians. On the other hand, recent technological advances have produced many real-world engineering applications that require the automatic con trol of mechanical systems. the mechanism for de Often, Lyapunov-based techniques are utilized as veloping different nonlinear control structures for mechanical systems. The allure of the Lyapunov-based framework for mechanical system control de sign can most likely be assigned to the fact that Lyapunov function candi dates can often be crafted from physical insight into the mechanics of the system. That is, despite the nonlinearities, couplings, and/or the flexible effects associated with the system, Lyapunov-based techniques can often be used to analyze the stability of the closed-loop system by using an energy like function as the Lyapunov function candidate. In practice, the design procedure often tends to be an iterative process that results in the death of many trees. That is, the controller and energy-like function are often constructed in concert to foster an advantageous stability property and/or robustness property. Fortunately, over the last 15 years, many system the ory and control researchers have labored in this area to produce various design tools that can be applied in a variety of situations."

This book addresses the need for a fundamental understanding of the physical origin, the mathematical behavior and the numerical treatment of models which include microstructure. Leading scientists present their efforts involving mathematical analysis, numerical analysis, computational mechanics, material modelling and experiment. The mathematical analyses are based on methods from the calculus of variations, while in the numerical implementation global optimization algorithms play a central role. The modeling covers all length scales, from the atomic structure up to macroscopic samples. The development of the models ware guided by experiments on single and polycrystals and results will be checked against experimental data.

The proceedings from Parallel CFD 2006 covers all aspects of parallel computings and its applications. Although CFD is one of basic tools for design procedures to produce machineries, such as automobiles, ships, aircrafts, etc., large scale parallel computing has been realized very recently, especially for the manufactures. Various applications in many areas could be experienced including acoustics, weather prediction and ocean modeling, flow control, turbine flow, fluid-structure interaction, optimization, heat transfer, hydrodynamics.
- Report on current research in the field in an area which is rapidly changing
- Subject is important to all interested in solving large fluid dynamics problems
- Interdisciplinary activity. Contributions include scientists with a variety of backgrounds

It is a great pleasure for me to introduce this book which has the main ambition to make thermodynamics more directly accessible to engineers and physicists by stressing the analogies with the other physical domains; this science has discouraged more than a few students. The book comes from the meeting of two persons: 1. Jean Thoma, inventor of hydrostatic machines and transmissions, pro fessor at the University of Waterloo (Canada), expert in simulation and pilgrim for the promotion of bond graphs around the world. 2. Belkacem Ould Bouamama, associated professor at the University of Science and Technology in Lille, France, specialist in industrial control and seduced by the richness and structure of the bond graph method. Thermodynamics is a difficult subject; its concepts like entropy, enthalpy, etc. are not intuitive and often very abstract. For this reason, it is current practice to neglect the thermal aspects, although they are necessarily there in all physical phenomena, and to use isothermal models. This is equivalent to think that the system is immersed in an infinite temperature reservoir and maintains its temperature constant even if it receives or dissipates electric and other type of energy. For heat transfer and variable temperature, if it should be included, the classical approach is to study the changes between equilibrium states, and not the process itself, which is more a thermostatic than a thermodynamic approach. This is justified when only the constraints of equilibrium state must be satisfied."

This book brings together papers from all spheres of mechanical engineering related to gears and transmissions, from fundamentals to advanced applications, from academic results in numerical and experimental research, to new approaches to gear design and aspects of their optimization synthesis and to the latest developments in manufacturing. Furthermore, this volume honours the work of Faydor L. Litvin on the 100th anniversary of this birth. He is acknowledged as the founder of the modern theory of gearing. An exhaustive list of his contributions and achievements and a biography are included.

Mastering modelling, and in particular numerical models, is becoming a crucial and central question in modern computational mechanics. Various tools, able to quantify the quality of a model with regard to another one taken as the reference, have been derived. Applied to computational strategies, these tools lead to new computational methods which are called "adaptive." The present book is concerned with outlining the state of the art and the latest advances in both these important areas.

Papers are selected from a Workshop (Cachan 17-19 September 1997) which is the third of a series devoted to Error Estimators and Adaptivity in Computational Mechanics. The Cachan Workshop dealt with latest advances in adaptive computational methods in mechanics and their impacts on solving engineering problems. It was centered too on providing answers to simple questions such as: what is being used or can be used at present to solve engineering problems? What should be the state of art in the year 2000? What are the new questions involving error estimators and their applications?