Review on thermal energy storage with phase change: materials, heat transfer analysis and applications

1. Introduction and overview 2. Film stress and substrate curvature 3. Stress in anisotropic and patterned films 4. Delamination and fracture 5. Film buckling, bulging and peeling 6. Dislocation formation in epitaxial systems 7. Dislocation interactions and strain relaxation 8. Equilibrium and stability of surfaces 9. The role of stress in mass transport.

Thin Film Materials: Stress, Defect Formation and Surface Evolution

The application of mass spectrometric techniques to the realtime measurement and characterization of aerosols represents a significant advance in the field of atmospheric science. This review focuses on the aerosol mass spectrometer (AMS), an instrument designed and developed at Aerodyne Research, Inc. (ARI) that is the most widely used thermal vaporization AMS. The AMS uses aerodynamic lens inlet technology together with thermal vaporization and electron-impact mass spectrometry to measure the real-time non-refractory (NR) chemical speciation and mass loading as a function of particle size of fine aerosol particles with aerodynamic diameters between similar to 50 and 1,000 nm. The original AMS utilizes a quadrupole mass spectrometer (Q) with electron impact (EI) ionization and produces ensemble average data of particle properties. Later versions employ time-of-flight (ToF) mass spectrometers and can produce full mass spectral data for single particles. This manuscript presents a detailed discussion of the strengths and limitations of the AMS measurement approach and reviews how the measurements are used to characterize particle properties. Results from selected laboratory experiments and field measurement campaigns are also presented to highlight the different applications of this instrument. Recent instrumental developments, such as the incorporation of softer ionization techniques (vacuum ultraviolet (VUV) photo-ionization, Li(+) ion, and electron attachment) and high-resolution ToF mass spectrometers, that yield more detailed information about the organic aerosol component are also described. (c) 2007 Wiley Periodicals, Inc.

/pdf/chemical-and-microphysical-characterization-of-ambient-3fnm4sju9e.pdf

Chemical and microphysical characterization of ambient aerosols with the aerodyne aerosol mass spectrometer

Atmospheric-pressure plasmas are used in a variety of materials processes. Traditional sources include transferred arcs, plasma torches, corona discharges, and dielectric barrier discharges. In arcs and torches, the electron and neutral temperatures exceed 3000/spl deg/C and the densities of charge species range from 10/sup 16/-10/sup 19/ cm/sup -3/. Due to the high gas temperature, these plasmas are used primarily in metallurgy. Corona and dielectric barrier discharges produce nonequilibrium plasmas with gas temperatures between 50-400/spl deg/C and densities of charged species typical of weakly ionized gases. However, since these discharges are nonuniform, their use in materials processing is limited. Recently, an atmospheric-pressure plasma jet has been developed, which exhibits many characteristics of a conventional, low-pressure glow discharge. In the jet, the gas temperature ranges from 25-200/spl deg/C, charged-particle densities are 10/sup 11/-10/sup 12/ cm/sup -3/, and reactive species are present in high concentrations, i.e., 10-100 ppm. Since this source may be scaled to treat large areas, it could be used in applications which have been restricted to vacuum. In this paper, the physics and chemistry of the plasma jet and other atmospheric-pressure sources are reviewed.

/pdf/the-atmospheric-pressure-plasma-jet-a-review-and-comparison-4n3xn1jiyb.pdf

The atmospheric-pressure plasma jet: a review and comparison to other plasma sources

Atmospheric pressure plasmas: A review

Plasma waste treatment has over the past decade become a more prominent technology because of the increasing problems with waste disposal and because of the realization of opportunities to generate valuable co-products. Plasma vitrification of hazardous slags has been a commercial technology for several years, and volume reduction of hazardous wastes using plasma processes is increasingly being used. Plasma gasification of wastes with low negative values has attracted interest as a source of energy and spawned process developments for treatment of even municipal solid wastes. Numerous technologies and approaches exist for plasma treatment of wastes. This review summarizes the approaches that have been developed, presents some of the basic physical principles, provides details of some specific processes and considers the advantages and disadvantages of thermal plasmas in waste treatment applications.

http://iopscience.iop.org/article/10.1088/0022-3727/41/5/053001/pdf

Thermal plasma waste treatment

This book is based on a series of continuing education courses which have been offered by the authors across the world in conjunction with the International Symposium on Plasma Chemistry (ISPC) as part of its summer school over the period 1995-2011. A similar course, though more oriented toward thermal spray technology, was also offered by the authors in conjunction with ASM International Thermal Spray Conferences (ITSC) over the period 1998-2010. Both courses were offered to graduate students, practicing engineers, and researchers actively involved in the field of thermal plasmas. Their emphasis was on the fundamentals behind plasma processing and thermal spray technology, and the aim was to provide a grassroot understanding of the basic phenomena involved, necessary for taking the technology over the crucial step from being an "art" based on operator talent and experience to a mature science with quantitative predictive capabilities. This step did not come easily and without the intense involvement of many leading researchers in this field across the world. The three determining factors which were of critical importance to the evolution of this field over the past three decades are as follows: * Major improvement in process diagnostics and online controls * The fast and significant development of numerical modeling and computing capabilities * Major development in materials science and materials characterization techniques In the process of preparation of the manuscript for this book, which spans many years, the authors were confronted with the critical need to strike a good balance between the need to be concise in the overall presentation of the subject and being inclusive in stressing the fundaments without overlooking the important applications which were the economical driver of the technology. New technologies were also developed over this period which, while not being "plasma technologies," were relevant to the overall field of surface treatment and coating. These were accordingly included in the book such as the combustion-based technologies and "cold spray." We have no pretensions about having covered every aspect of this technology or exhaustively reported on every relevant publication in this field. Exhaustive lists of references are given at the end of each chapter. For those who were not cited, our apologies, it was not intentional. A book of this size and scope could not have been possible without the extensive help of students, research assistants, colleagues, and associates. Our sincere thanks to all who have helped make this book a reality. Particular thanks are due to Dr. Rudolf Henne who so generously gave his time in the process of reviewing the manuscript of the book in its final preparation stage. We also appreciate his willingness to write the foreword for this book which reflects his long and broad experience in the field of thermal spray. The financial assistance of the numerous government and private funding agencies and industrial partners who have also supported the basic and applied research behind this technology in our respective research laboratories is gratefully acknowledged. Our sincere thanks to our respective families and life partners, Paulette Fauchais, Yuko Heberlein, and Alice Boulos who had to cope with the long hours of intense personal efforts that were needed to complete this book.

Thermal Spray Fundamentals : From Powder to Part

Successful deposition and mechanical probing of nearly spherical, defect-free silicon nanospheres has been accomplished. The results show silicon at this length scale to be up to four times harder than bulk silicon. Detailed measurements of plasticity evolution and the corresponding hardening response in normally brittle silicon is possible in these small volumes. Based upon a proposed length scale related to the size of nanospheres in the 20– 50 nm radii range, a prediction of observed hardnesses in the range of 20– 50 GPa is made. The ramifications of this to computational materials science studies on identical volumes are discussed.

Superhard silicon nanospheres

The control over coating quality in plasma spraying is partly dependent on the arc and jet instabilities of the plasma torch. Different forms of instabilities have been observed with different effects on the coating quality. We report on an investigation of these instabilities based on high-speed end-on observation of the arc. The framing rate of 40,500 frames per second has allowed the visualization of the anode attachment movement and the determination of the thickness of the cold-gas boundary layer surrounding the arc. The images have been synchronized with voltage traces. Data have been obtained for a range of arc currents, and mass flow rates for different gas injectors and for anodes displaying different amounts of wear. The analysis of the data has led to quantitative correlations between the cold-gas boundary layer thickness and the instability mode for the range of operating parameters. The arc instabilities can be seen to enhance the plasma jet instabilities and the cold-gas entrainment. These results are particularly useful for guiding plasma torch design and operation in minimizing the influence of plasma jet instabilities on coating properties.

Arc instabilities in a plasma spray torch

Arc plasma torches are the primary components of various industrial thermal plasma processes involving plasma spraying, metal cutting and welding, thermal plasma CVD, metal melting and remelting, waste treatment, and gas production. They are relatively simple devices whose operation implies intricate thermal, chemical, electrical, and fluid dynamics phenomena. Modeling may be used as a means to better understand the physical processes involved in their operation. This article presents an overview of the main aspects involved in the modeling of DC arc plasma torches: the mathematical models including thermodynamic and chemical nonequilibrium models, turbulent and radiative transport, thermodynamic and transport property calculation, boundary conditions, and arc reattachment models. It focuses on the conventional plasma torches used for plasma spraying that include a hot cathode and a nozzle anode.

https://link.springer.com/content/pdf/10.1007%2Fs11666-009-9342-1.pdf

Joachim Heberlein

Papers

Thermal plasma waste treatment

Thermal Spray Fundamentals : From Powder to Part

Superhard silicon nanospheres

Arc instabilities in a plasma spray torch

Arc Plasma Torch Modeling