الصفحة 1
الصفحة 1
Multiphase Flow Dynamics 3 : Turbulence, Gas Absorption and Release, Diesel Fuel Properties
Volume 3 is devoted to selected Chapters of the multiphase fluid dynamics that are important for practical applications. The state of the art of the turbulence modeling in multiphase flows is presented. As introduction, some basics of the single-phase boundary layer theory including some important scales and flow oscillation characteristics in pipes and rod bundles are presented. Then the scales characterizing the dispersed flow systems are presented. The description of the turbulence is provided at different level of complexity: simple algebraic models for eddy viscosity, algebraic models based on the Boussinesq hypothesis, modification of the boundary layer share due to modification of the bulk turbulence, modification of the boundary layer share due to nucleate boiling. Then the role of the following forces on the matematical description of turbulent flows is discussed: the lift force, the lubrication force in the wall boundary layer, and the dispersion force.
Modelling the dispersion of radionuclides in the marine environment : An introduction
This book is a practical guide to the subject of numerical modelling of radioactivity dispersion in the marine environment. Thus, the techniques and numerical procedures required are explained in detail, with the aim of enabling the reader to build a real mathematical model. The book covers basic concepts and techniques, such as solving the advection-diffusion equation in a simple 1D form, as well as the most recent developments (full 3D models for non-conservative radionuclides including chemical reactions and speciation). A chapter is dedicated to the basic hydrodynamic modelling that is always required to simulate the dispersion of tracers in the sea; Eulerian and Lagrangian modelling techniques are also described. A chapter describes sensitivity and uncertainty analysis, the final stage in modelling works. A review on some published radionuclide dispersion models is also included.
Group theory : Application to the physics of condensed matter
Every process in physics is governed by selection rules that are the consequence of symmetry requirements. The beauty and strength of group theory resides in the transformation of many complex symmetry operations into a very simple linear algebra. This concise and class-tested book has been pedagogically tailored over 30 years MIT and 2 years at the University Federal of Minas Gerais (UFMG) in Brazil. The approach centers on the conviction that teaching group theory in close connection with applications helps students to learn, understand and use it for their own needs. For this reason, the theoretical background is confined to the first 4 introductory chapters (6-8 classroom hours). From there, each chapter develops new theory while introducing applications so that the students can best retain new concepts, build on concepts learned the previous week, and see interrelations between topics as presented.
Forces, Growth and Form in Soft Condensed Matter : At the Interface between Physics and Biology
This volume comprises the proceedings of a NATO Advanced Study Institute held at Geilo, Norway, 24 March - 3 April 2003, the seventeenth ASI in a series held every two years since 1971. The objective of this ASI was to identify and discuss areas where synergism between modern physics, soft condensed matter and biology might be most fruitful. The main pedagogical approach was to have lecturers focussing on basic understanding of important aspects of the relative role of the various interaction- electrostatic, hydrophobic, steric, conformational, van der Waals etc. Soft condensed matter and the connection between physics and biology have been the themes of several earlier Geilo Schools. A return to these subjects thus allowed a fresh look and a possibility for defining new directions for research. Examples of soft materials, which were discussed at this ASI, included colloidal dispersions, gels, biopolymers and charged polymer solutions, polyelectrolytes, protein/membrane complexes, nucleic acids and their complexes. Indeed, most forms of condensed matter are soft and these substances are composed of aggregates and macromolecules, with interactions that are too weak and complex to form crystals spontaneously. A characteristic feature is that small external forces, slight perturbations in temperature, pressure or concentration, can all be enough to induce significant structural changes. Thermal fluctuations are almost by definition strong in soft materials and entropy is a predominant determinant of structure, so that disorder, slow dynamics and plastic deformation are the rule. Hence the phrase ‘soft condensed matter’ has been coined.
Fiber-Optic Communication Systems
Contains substantial additions covering the topics of coherence detection, space division multiplexing, and more advanced subjects. You'll learn about topics like fiber’s losses, dispersion, and nonlinearities, as well as coherent lightwave systems. The latter subject has undergone major changes due to the extensive development of digital coherent systems over the last decade. Space-division multiplexing is covered as well, including multimode and multicore fibers developed in just the last ten years.
Fiber-based Dispersion Compensation
Dispersion management is a critical design criterion that characterizes the performance of an optical network, and has impacted almost every aspect of the physical layer of an optical transmission line. The past 10 years have seen an explosion in the variety of device effects exploited to obtain optimal performance from dispersion compensators, and this is the first book that deals exclusively with this technology.
Enhancing the Dissolution Rate of Atorvastatin by Solid Dispersion Technique
In the last few decades, solid dispersion (SD) technology had been studied as an approach to produce an amorphous carrier to enhance the solubility, dissolution rate, and bioavailability of poorly water-soluble drugs. The use of suitable carrier and methodology in the preparation of SDs play a significant role in the biological behavior of the SDs. Atorvastatin is a statin group HMG-CoA reductase inhibitor drug that is commonly used to adverse cardiovascular events and to lower blood total cholesterol and LDL-cholesterol. the solubility of atorvastatin in water is very low (0.1 mg mL− 1), which results in reduced bioavailability. In order to enhance its solubility, we have prepared solid dispersions (SDs) of atorvastatin at different drug: polymer ratios (1:2, 1:10, 1:20,1:25 and 1:40), using polyethylene glycol 6000 as polymer and different preparation methods (co-precipitate and melting methods) The characterization of the SDs was performed using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) The solubility of AT was improved by the incorporation PEG6000.
Electromagnetic and Optical Pulse Propagation 1 : Spectral Representations in Temporally Dispersive Media
Electromagnetic & Optical Pulse Propagation presents a systematic treatment of the radiation and propagation of transient electromagnetic and optical wave fields through causal, locally linear media which exhibit both temporal dispersion and absorption.
Development and characterization of a dispersion-encoded method for low-coherence interferometry
This book discusses an extension to low-coherence interferometry by dispersion-encoding. The approach is theoretically designed and implemented for applications such as surface profilometry, polymeric cross-linking estimation and the determination of thin-film layer thicknesses. During a characterization, it was shown that an axial measurement range of 79.91 µm with an axial resolution of 0.1 nm is achievable. Simultaneously, profiles of up to 1.5 mm in length were obtained in a scan-free manner. This marked a significant improvement in relation to the state-of-the-art in terms of dynamic range.
Correlated Data Analysis : Modeling, Analytics, and Applications
Presents some recent developments in correlated data analysis. It utilizes the class of dispersion models as marginal components in the formulation of joint models for correlated data. This enables the book to handle a broader range of data types than those analyzed by traditional generalized linear models.
Computational Electromagnetics
Computational Electromagnetics is a young and growing discipline, expanding as a result of the steadily increasing demand for software for the design and analysis of electrical devices. This book introduces three of the most popular numerical methods for simulating electromagnetic fields: the finite difference method, the finite element method and the method of moments. In particular it focuses on how these methods are used to obtain valid approximations to the solutions of Maxwell's equations, using, for example, "staggered grids" and "edge elements." The main goal of the book is to make the reader aware of different sources of errors in numerical computations, and also to provide the tools for assessing the accuracy of numerical methods and their solutions. To reach this goal, convergence analysis, extrapolation, von Neumann stability analysis, and dispersion analysis are introduced and used frequently throughout the book. Another major goal of the book is to provide students with enough practical understanding of the methods so they are able to write simple programs on their own. To achieve this, the book contains several MATLAB programs and detailed description of practical issues such as assembly of finite element matrices and handling of unstructured meshes.
Light Scattering in Solids IX : Novel Materials and Techniques
Reviews recent developments concerning mainly semiconductor nanostructures and inelastic x-ray scattering, including both coherent time-domain and spontaneous scattering studies.
Light Scattering from Polymer Solutions and Nanoparticle Dispersions
Light scattering is a very powerful method to characterize the structure of polymers and nanoparticles in solution. Recent technical developments have strongly enhanced the possible applications of this technique, overcoming previous limitations like sample turbidity or insufficient experimental time scales. However, despite their importance, these new developments have not yet been presented in a comprehensive form. In addition, and maybe even more important to the broad audience, there lacks a simple-to-read textbook for students and non-experts interested in the basic principles and fundamental techniques of light scattering. As part of the Springer Laboratory series, this book tries not only to provide such a simple-to-read and illustrative textbook about the seemingly very complicated topic of light scattering from polymers and nanoparticles in dilute solution, but also intends to cover some of the newest technical developments in experimental light scattering.
IUTAM symposium on computational approaches to multiphase flow ; Proceedings of an IUTAM Symposium held at Argonne National Laboratory, October 4-7, 2004
The book provides a broad overview of the full spectrum of state-of-the-art computational activities in multiphase flow as presented by top practitioners in the field. It starts with well-established approaches and builds up to newer methods. These methods are illustrated with applications to a broad spectrum of problems involving particle dispersion and deposition, turbulence modulation, environmental flows, fluidized beds, bubbly flows, and many others.
Artificial neural networks in Vehicular Pollution Modelling
Artificial neural networks (ANNs), which are parallel computational models, comprising of interconnected adaptive processing units (neurons) have the capability to predict accurately the dispersive behavior of vehicular pollutants under complex environmental conditions. This book aims at describing step-by-step procedure for formulation and development of ANN based VP models considering meteorological and traffic parameters. The model predictions are compared with existing line source deterministic/statistical based models to establish the efficacy of the ANN technique in explaining frequent dispersion complexities in urban areas. The book is very useful for hardcore professionals and researchers working in problems associated with urban air pollution management and control.
Antecedents of venture firms' internationalization : A conjoint analysis of international entrepreneurship in the net economy
With the continuing dispersion of the global digital network and performance improvements of information and communication technologies, resource-poor start-ups with online business models have emerged in large numbers. These firms are able to deploy their competitive advantages across their country borders early in their life-cycle and engage in international commerce at a fast pace. An increased immediacy between the firms and the globally accessible customer is observed. Julia Christofor’s study aims to analyze the conditions of the initial internationalization decision in the Net Economy. Based on Information Systems, International Entrepreneurship, and Entrepreneurship literature, factors, which constitute the internationalization propensity, are derived. The results of this study suggest that a holistic perspective including the founder, business model and the firm level should be considered when explaining the internationalization propensity of entrepreneurs.
Analytical Ultracentrifugation of Polymers and Nanoparticles
Analytical ultracentrifugation (AUC) is a powerful method for the characterization of polymers, biopolymers, polyelectrolytes, nanoparticles, dispersions, and other colloidal systems. The method is able to determine the molar mass, the particle size, the particle density and interaction parameters like virial coefficients and association constants. Because AUC is also a fractionation method, the determination of the molar mass distribution, the particle size distribution, and the particle density distribution is possible. A special technique, the density gradient method, allows fractionating heterogeneous samples according to their chemical nature that means being able to detect chemical heterogeneity.
Advanced technique and future perspective for next generation optical fiber communications
Optical fiber communication industry has gained unprecedented opportunities and achieved rapid progress in recent years. However, with the increase of data transmission volume and the enhancement of transmission demand, the optical communication field still needs to be upgraded to better meet the challenges in the future development. Artificial intelligence technology in optical communication and optical network is still in its infancy, but the existing achievements show great application potential. In the future, with the further development of artificial intelligence technology, AI algorithms combining channel characteristics and physical properties will shine in optical communication. This reprint introduces some recent advances in optical fiber communication and optical network, and provides alternative directions for the development of the next generation optical fiber communication technology.
