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Material Processing (material + processing)
Selected AbstractsKnowledge Management for Materials Processing,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2005W. Rentzsch Manufacturing knowledge is often embedded in the minds of different experts or is not effectively shared between manufacturing stages. Many companies are therefore running the risk of missing or loosing critical information. This study discusses the concept of "knowledge maps" to document the interactions between all stages of the manufacturing process and all product attributes. Potential applications of knowledge maps in manufacturing are discussed and explored in a detailed case study. [source] Modeling and Simulation of Fast Neutral Beam Sources for Materials ProcessingPLASMA PROCESSES AND POLYMERS, Issue 5 2009Demetre J. EconomouArticle first published online: 6 MAY 200 Abstract Fast (kinetic energy of 10 to some 100 eV) neutral beams can be used for etching, deposition or surface modification, without charging damage that may occur in conventional plasma processing of materials. This paper provides an overview of the modeling and simulation approaches applicable to neutral beam sources. Neutral beam sources based on both volume and surface neutralization of ions are discussed, with emphasis on the latter. [source] A novel growth method for ZnAl2O4 single crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2006K. Kumar Abstract ZnAl2O4 is a well-known wide band gap compound semiconductor (Eg=3.8eV), ceramic, opto-mechanical, anti-thermal coating in aero-space vehicles and UV optoelectronic devices. A novel method for the growth of single crystals of a ternary oxide material was developed as a fruit of a long term work. Material to be grown as metal incorporated single crystal was taken as precursor and put into a bath containing acid as reaction speed up reagent (catalyst) as well as solvent with a metal foil as cation scavenger. Using this method, ZnAl2O4 crystals having hexagonal facets are prepared from a single optimized bath. Structural and compositional properties of crystals were studied using Philips, Xpert - MPD: X-ray diffractometer and Philips, ESEM-TMP + EDAX. Thus technique was found to be a new low cost and advantageous method for growth of single crystals of ternary oxide a material. We hope that these data be helpful either as a scientific or technical basis in material processing. Dedicated to Prof. P. Ramasamy © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [source] Proposed life prediction model for laser-formed high-strength low-alloy curved componentsFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 4 2007P. J. McGRATH ABSTRACT Techniques employed for material processing using laser technology are progressing at a rapid pace. One such technique is that of forming sheet metal plates. This high-intensity localized heating process allows for forming of metallic sheet materials without the need for expensive tools and dies or any mechanical assistance. The fundamental mechanisms related to this process are reasonably well understood and documented but there remain areas that require further research and development. One such area is the fatigue behaviour of sheet materials manufactured by this novel process. Hence, the proceeds of this paper deal with fatigue life prediction of sheet metal components laser-formed to a radius with a curvature of approximately 120 mm. The approach to this proposed model considers the mean stress relationship as given by Gerber and a prediction model derived from combining the aspects of life prediction models according to Collins and Juvinall & Marshek. [source] Integration of lakes and streams in a landscape perspective: the importance of material processing on spatial patterns and temporal coherenceFRESHWATER BIOLOGY, Issue 3 2000George W. Kling 1. We studied the spatial and temporal patterns of change in a suite of twenty-one chemical and biological variables in a lake district in arctic Alaska, U.S.A. The study included fourteen stream sites and ten lake sites, nine of which were in a direct series of surface drainage. All twenty-four sites were sampled between one and five times a year from 1991 to 1997. 2. Stream sites tended to have higher values of major anions and cations than the lake sites, while the lake sites had higher values of particulate carbon, nitrogen, phosphorous and chlorophyll a. There were consistent and statistically significant differences in concentrations of variables measured at the inlet versus the outlet of lakes, and in variables measured at upstream versus downstream sites in the stream reaches which connect the lakes. In-lake processing tended to consume alkalinity, conductivity, H+, DIC, Ca2+, Mg2+, CO2, CH4, and NO3,, and produce K+ and dissolved organic carbon (DOC). In-stream processing resulted in the opposite trends (e.g. consumption of K+ and DOC), and the magnitudes of change were often similar to those measured in the lakes but with the opposite sign. 3. Observed spatial patterns in the study lakes included mean concentrations of variables which increased, decreased or were constant along the lake chain from high to low altitude in the catchment (stream sites showed no spatial patterns with any variables). The strongest spatial patterns were of increasing conductivity, Ca2+, Mg2+, alkalinity, dissolved inorganic carbon and pH with lake chain number (high to low altitude in the basin). These patterns were partly determined by the effect of increasing catchment area feeding into lakes further downslope, and partly by the systematic processing of materials in lakes and in the stream segments between lakes. 4. Synchrony (the temporal coherence or correlation of response) of variables across all lakes ranged from 0.18 for particulate phosphorus to 0.90 for Mg2+ the average synchrony for all twenty-one variables was 0.50. The synchronous behaviour of lake pairs was primarily related to the spatial location or proximity of the lakes for all variables taken together and for many individual variables, and secondarily, to the catchment to lake area ratio and the water residence time. 5. These results illustrate that, over small geographic areas, and somewhat independent of lake or stream morphometry, the consistent and directional (downslope) processing of materials helps produce spatial patterns which are coherent over time for many limnological variables. We combine concepts from stream, lake and landscape ecology, and develop a conceptual view of landscape mass balance. This view highlights that the integration of material processing in both lakes and rivers is critical for understanding the structure and function of surface waters, especially from a landscape perspective. [source] Modeling UHMWPE wear debris generationJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2007H. Baudriller Abstract It is widely recognized that polyethylene wear debris is one of the main causes of long-term prosthesis loosening. The noxious bioreactivity associated with this debris is determined by its size, shape, and quantity. The aim of this study was to develop a numerical tool that can be used to investigate the primary polyethylene wear mechanisms involved. This model illustrates the formation of varying flow of polyethylene debris with various shapes and sizes caused by elementary mechanical processes. Instead of using the classical continuum mechanics formulation for this purpose, we used a divided materials approach to simulate debris production and release. This approach involves complex nonlinear bulk behaviors, frictional adhesive contact, and characterizes material damage as a loss of adhesion. All the associated models were validated with various benchmark tests. The examples given show the ability of the numerical model to generate debris of various shapes and sizes such as those observed in implant retrieval studies. Most of wear mechanisms such as abrasion, adhesion, and the shearing off of micro-asperities can be described using this approach. Furthermore, it could be applied to study the effects of friction couples, macroscopic geometries, and material processing (e.g. irradiation) on wear. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007 [source] Dielectric properties of pharmaceutical materials relevant to microwave processing: Effects of field frequency, material density, and moisture contentJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2010Paul W.S. Heng Abstract The rising popularity of microwaves for drying, material processing and quality sensing has fuelled the need for knowledge concerning dielectric properties of common pharmaceutical materials. This article represents one of the few reports on the density and moisture content dependence of the dielectric properties of primary pharmaceutical materials and their relevance to microwave-assisted processing. Dielectric constants and losses of 13 pharmaceutical materials were measured over a frequency range of 1,MHz,1,GHz at 23,±,1°C using a parallel-electrode measurement system. Effects of field frequency, material density and moisture content on dielectric properties were studied. Material dielectric properties varied considerably with frequency. At microwave frequencies, linear relationships were established between cube-root functions of the dielectric parameters ( and ) and density which enabled dielectric properties of materials at various densities to be estimated by regression. Moisture content was the main factor that contributed to the disparities in dielectric properties and heating capabilities of the materials in a laboratory microwave oven. The effectiveness of a single frequency density-independent dielectric function for moisture sensing applications was explored and found to be suitable within low ranges of moisture contents for a model material. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:941,957, 2010 [source] High Power Diode Lasers for Industrial ApplicationsLASER TECHNIK JOURNAL, Issue 3 2007Wolfgang Horn New wavelengths, high brightness and increasing reliability are breaking new ground for diode lasers. The higher brightness allows direct fiber coupling of several 100 W in 200 ,m and 400 ,m fibers and therefore i.e. the pumping of fiber lasers. Such high power fiber coupled laser diodes combined with fast beam deflection units (galvo scanners) have been implemented in industrial processes and used for quasi-simultaneous welding of polymers, heat treatment in the sub millimeter range or selective soldering in solar cell production. Besides pumping of solid state lasers, high power diode lasers become more and more a competitive tool for many applications in material processing. [source] John Wiley & Sons: 200th anniversary!LASER TECHNIK JOURNAL, Issue 1 2007Andreas Thoß Dr. This year, the publisher John Wiley & Sons celebrates its 200th anniversary. When Charles Wiley first opened his print shop in lower Manhattan in 1807, America was a young nation, full of potential and seeking its cultural identity on the global stage. Wiley was there, contributing to the emerging American literary tradition by publishing such great 19th century American writers as James Fenimore Cooper, Washington Irving, Herman Melville, and Edgar Allan Poe. Later on, Wiley published the works of outstanding European writers such as Hans Christian Andersen, Charles Dickens, John Ruskin, and Elizabeth Barrett Browning. Yet, during the second industrial revolution , and its resulting knowledge revolution , Wiley abandoned its literary programme to pursue knowledge publishing for a global community. Today Wiley publishes a broad variety of journals, encyclopedias, books, and online products. The spectrum reaches from medicine to astronomy, from trade journals to consumer books and it includes educational materials for students as well as for lifelong learners. Since 1807, the world has seen 41 U.S. Presidents, but there have only been ten Wiley Presidents. Today, Wiley is a publicly held, independently managed family business. That is the formula of success that has sustained the company for two centuries. In 2007 Wiley is one of the major global publishers with more than one billion dollar revenue and about 3.900 employees. This will increase even more, when the acquisition of Blackwell Publishing will be completed in 2007. Aged only three years, the Laser Technik Journal is one of the youngest among the Wiley Journals. But it fits well in the history of Wiley. Thomas Alva Edison, the "Wizard of Menlo Park", held William H. Wiley in high regard, and so there is a long tradition of close contacts between the publishing house and the engineering community. The purpose of the journals has changed little: Our mission is to provide the community with up to date information on the latest in technology, reports and discussions on trends and markets, and finally the journal serves as a forum for key people from science and business to share their visions and experiences. 2007 will be a great year not only for Wiley, but for the laser community as well. Company reports from Coherent, Trumpf or Rofin Sinar show two-digit growths and excellent earnings. Record numbers are expected also at conferences and trade shows. At Photonics West in San Jose, CA, 1.000 exhibitors and more than 15.000 visitors are expected. The Laser. World of Photonics 2007 in Munich (June) will be even bigger. It is a "can't miss" event particularly for those visitors interested in Laser material processing. The Laser Technik Journal will be on both shows. Please stop by at the Wiley booth, for a chat or to see the latest from the Wiley book program! [source] Tuneable Femtosecond Fiber Lasers , Ultra-short laser pulses from green to IRLASER TECHNIK JOURNAL, Issue 2 2005Jan Posthumus Dr. There is a wealth of applications for ultra-short, pulsed lasers in many areas of science and technology, material processing and also in medicine. However, their widespread use is severely hampered by the size and cost of these lasers, both in terms of acquisition and maintenance. This implies that there could be a large market for affordable, turn-key femtosecond lasers (1 fs = 10,15 s). A technical solution is now possible with a new generation of fiber lasers, which are made of standard telecom components. These fiber lasers are compact (A4 size) and scalable in cost and performance. They can also be produced in large volumes. They render water cooling methods and large power supplies obsolete. [source] Zur Modellierung von Zerkleinerungsprozessen,CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 3 2005Dr.-Ing., K. Husemann Prof., habil. Abstract Die Bedeutung der Zerkleinerung für die industrielle Stoffwandlung ist groß und die Angebotspalette an Zerkleinerungsmaschinen , angepasst an die Festigkeit/Härte des Mahlgutes, die Ausgangsmaterial- und Mahlproduktfeinheit, den notwendigen Durchsatz u.,a. , breit. Die Beschreibung der Zerkleinerung ist auch heute trotz der erreichten Fortschritte bei den Grundlagen der Zerkleinerung und den Kenntnissen der Vorgänge in Zerkleinerungsmaschinen nur eingeschränkt möglich. Vor diesem Hintergrund ist die Modellierung der Zerkleinerung von der Modellvorstellung bis zum mathematischen Algorithmus notwendig und hilfreich. Im Beitrag werden verschiedene Modellierungsmöglichkeiten dargestellt und dabei zwischen Regressionsmodellen für die Prozesse in Zerkleinerungsmaschinen, Modellvorstellungen aus den Grundlagen der Zerkleinerung und Modellen für die Zerkleinerung aus der allgemeinen Prozessgleichung der mechanischen Verfahrenstechnik unterschieden. Modeling of Comminution Processes The importance of comminution processes for industrial material processing is crucial and the available selection of crushers and mills , adapted to strength/hardness of the material to be ground, the fineness of the feed and product, the throughput required, etc. , is wide. The description of a comminution process is also nowadays , despite the progress as to the fundamentals of comminution and as to the knowledge of the processes in comminution equipment , possible only to a limited extent. In this respect, modeling and simulation of comminution from the model to a mathematical algorithm is necessary and helpful. In this contribution, several possible models are presented: regression models, models derived from the fundamentals of comminution processes and, finally, models related to the general process equation of mechanical process engineering. [source] | ||||||||||||||||