1. New Developments in Deformation Studies: High-Strain Deformation

2002 ◽  
pp. 1-20 ◽  
Author(s):  
Stephen J. Mackwell ◽  
Mervyn S. Paterson
Keyword(s):  
High Strain ◽  
New Developments

New Developments in Deformation Studies: High-Strain Deformation

2002 ◽  
Vol 51 (1) ◽  
pp. 1-19 ◽  
Author(s):  
S. J. Mackwell ◽  
M. S. Paterson
Keyword(s):  
High Strain ◽  
New Developments

Solid Solution Effects and Deformation Micros trueture of Shock-Loaded Iron Manganese Alloys

1970 ◽  
Vol 28 ◽  
pp. 420-421
Author(s):  
A. Christou ◽  
J. V. Foltz ◽  
N. Brown
Keyword(s):  
Solid Solution ◽  
Shock Loading ◽  
High Strain ◽  
Local Stress ◽  
Strain Rates ◽  
Local Stress Concentration ◽  
Bcc Metals ◽  
Manganese Alloys ◽  
Iron Manganese ◽  
Transmission Microscope

In general, all BCC transition metals have been observed to twin under appropriate conditions. At the present time various experimental reports of solid solution effects on BCC metals have been made. Indications are that solid solution effects are important in the formation of twins. The formation of twins in metals and alloys may be explained in terms of dislocation mechanisms. It has been suggested that twins are nucleated by the achievement of local stress-concentration of the order of 15 to 45 times the applied stress. Prietner and Leslie have found that twins in BCC metals are nucleated at intersections of (110) and (112) or (112) and (112) type of planes.In this paper, observations are reported of a transmission microscope study of the iron manganese series under conditions in which twins both were and were not formed. High strain rates produced by shock loading provided the appropriate deformation conditions. The workhardening mechanisms of one alloy (Fe - 7.37 wt% Mn) were studied in detail.

Plastic Deformation in Microtomed Sections

1971 ◽  
Vol 29 ◽  
pp. 458-459
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Applied Stress ◽  
Elastic Strain ◽  
High Strain ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Structure ◽  
Geometrical Constraints

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.

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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