Noncontact ultrasound studies of composite materials: new developments

2000 ◽  
Author(s):  
Christopher Edwards ◽  
Theodosia Stratoudaki ◽  
Stephen Dixon ◽  
Stuart B. Palmer
Keyword(s):  
Composite Materials ◽  
New Developments ◽  
Ultrasound Studies

Comparative Microstructures of Ion Milled and Electrochemically Thinned Composite Materials

1974 ◽  
Vol 32 ◽  
pp. 546-547
Author(s):  
R.R. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Composite Materials ◽  
Great Difficulty ◽  
Ion Milling ◽  
Transmission Electron ◽  
Ion Damage ◽  
Intermetallic Composite

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.

Transmission electron microscopy of composite materials

1988 ◽  
Vol 46 ◽  
pp. 1012-1015
Author(s):  
K.P.D. Lagerlof
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Structural Defects ◽  
Structural Composites ◽  
Multiphase Materials ◽  
Structural Reinforcement ◽  
Transmission Electron ◽  
Reinforced Fiber ◽  
Particulate Reinforced Composites ◽  
Definition Of

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

Instrumental Assessment in Cleft Palate Care

2013 ◽  
Vol 23 (2) ◽  
pp. 49-61 ◽  
Author(s):  
Jamie Perry ◽  
Graham Schenck
Keyword(s):  
Cleft Palate ◽  
New Developments ◽  
Perceptual Evaluation ◽  
Advantages And Disadvantages ◽  
Instrumental Assessment ◽  
Speech Language Pathologist ◽  
Hypernasal Speech ◽  
Perceptual Assessment ◽  
Velopharyngeal Function ◽  
And Function

Despite advances in surgical management, it is estimated that 20–30% of children with repaired cleft palate will continue to have hypernasal speech and require a second surgery to create normal velopharyngeal function (Bricknell, McFadden, & Curran, 2002; Härtel, Karsten, & Gundlach, 1994; McWilliams, 1990). A qualitative perceptual assessment by a speech-language pathologist is considered the most important step of the evaluation for children with resonance disorders (Peterson-Falzone, Hardin-Jones, & Karnell, 2010). Direct and indirect instrumental analyses should be used to confirm or validate the perceptual evaluation of an experienced speech-language pathologist (Paal, Reulbach, Strobel-Schwarthoff, Nkenke, & Schuster, 2005). The purpose of this article is to provide an overview of current instrumental assessment methods used in cleft palate care. Both direct and indirect instrumental procedures will be reviewed with descriptions of the advantages and disadvantages of each. Lastly, new developments for evaluating velopharyngeal structures and function will be provided.

New developments in hematopoetic stem cell transplantation

2002 ◽  
Vol 59 (11) ◽  
pp. 571-576 ◽  
Author(s):  
Gratwohl
Keyword(s):  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Ältere Patienten ◽  
Solide Tumoren ◽  
Aplastische Anämie ◽  
New Developments ◽  
Lymphoproliferative Erkrankungen ◽  
Hematopoetic Stem Cell ◽  
Angeborene Erkrankungen ◽  
Hematopoetic Stem Cell Transplantation

Die Transplantation hämatopoietischer Stammzellen umfasst heute Stammzellen aus Knochenmark, peripherem Blut oder Nabelschnurblut. Leukämien, Lymphoproliferative Erkrankungen, aplastische Anämie und schwere angeborene Erkrankungen des Knochenmarkes sind Hauptindikationen für allogene, lymphoproliferative Erkrankungen, Leukämien, solide Tumoren und schwere Autoimmunkrankheiten Hauptindikationen für autologe Transplantationen. Neue Verfahren wie reduzierte Konditionierung und selektive Gabe von Spenderlymphozyten eröffnen die Stammzelltransplantation auch für ältere Patienten und für solche mit vorbestehender Komorbidität. Wenn immer möglich, wird die Transplantation ab Diagnose in den Behandlungsplan integriert. Die Wahl des Verfahrens und des geeigneten Zeitpunktes wird nach individuellem Risikoprofil erstellt. Alter oder Diagnose sind nicht mehr alleinige Entscheidungskriterien. Als etablierte Therapieform dürfte die hämatopoietische Stammzelltransplantation als Modell dienen für Stammzelltransplantationen auch anderer Organe.

What’s Next?

2011 ◽  
Vol 23 (1) ◽  
pp. 60-63 ◽  
Author(s):  
Peter Vorderer
Keyword(s):  
Cultural Differences ◽  
Factor Model ◽  
New Developments ◽  
Theoretical Concepts ◽  
Open Questions ◽  
Entertainment Products ◽  
Entertainment Theory

This paper points to new developments in the context of entertainment theory. Starting from a background of well-established theories that have been proposed and elaborated mainly by Zillmann and his collaborators since the 1980s, a new two-factor model of entertainment is introduced. This model encompasses “enjoyment” and “appreciation” as two independent factors. In addition, several open questions regarding cultural differences in humans’ responses to entertainment products or the usefulness of various theoretical concepts like “presence,” “identification,” or “transportation” are also discussed. Finally, the question of why media users are seeking entertainment is brought to the forefront, and a possibly relevant need such as the “search for meaningfulness” is mentioned as a possible major candidate for such an explanation.

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