276,658 research outputs found
Experimental investigation into the effect of substrate clamping on the piezoelectric behaviour of thick-film PZT elements
No full textThis paper details an experimental investigation of the clamping effect associated with thick-film piezoelectric elements printed on a substrate. The clamping effect reduces the measured piezoelectric coefficient, d33, of the film. This reduction is due to the influence of the d31 component in the film when a deformation of the structure occurs, by either the direct or indirect piezoelectric effect. Theoretical analysis shows a reduction in the measured d33 of 62%, i.e. a standard bulk lead zirconate titanate (PZT)-5H sample with a manufacturer specified d33 of 593pC/N would fall to 227.8pC/N. To confirm this effect, the d33 coefficients of five thin bulk PZT-5H samples of 220µm thickness were measured before and after their attachment to a metallized 96% alumina substrate. The experimental results show a reduction in d33 of 74% from 529pC/N to 139pC/N. The theoretical analysis was then applied to existing University of Southampton thick-film devices. It is estimated that the measured d33 value of 131pC/N of the thick-film devices is the equivalent of an unconstrained d33 of 345pC/N
White Collection; no.05281
No full textSepia image of 16 individuals standing on the steps of the White House after witnessing President William Howard Taft's signing of New Mexico Statehood Admission papers, January 6th, 1912. Image mounted on an off white matte board. Stamped on the lower middle edge of matte board; ""Harris & Ewing 1311 F. Street N. W. Washington, D. C.""Master file: image/tiff; 242,220 KB; Computer Hardware: Intel Pentium (R) 4 3.20 GHz/ 1.99 GB RAM manufactured by Dell; Operating system: Windows XP 2002; Creation software: Adobe Photoshop CS2 version 9.0.2; Scanner: flatbed reflective scanner Microtek 1000XL; Scanner software: Microtek SilverFast Ai 6.4.2r2b; Scanned by Jackie Becker on 2009-10-15
Figures Don't Lie: Spatial Humanities and Technology as Critical Thinking Tools
No full textThis presentation demonstrates the potential use of spatial humanities as both a critical thinking exercise and a computational tool in digital humanities pedagogy. “Figures Don’t Lie” presents a map of the United States that labels each state as a foreign nation according to the correlation between the GDPs of each state and their assigned countries. The map may spark classroom discussions about a range of humanities topics. Revealing the map’s underlying data shows how facts can be spun and helps students understand how the “facts” presented in the media may not be what they appear.Presented at Rutgers University's "Digital Humanities Showcase: New Methods and New Media" on January 29, 2014 (New Brunswick, N.J.)
Calculating All That Jazz: Linking Technical Specifications to the Management of Digitization Projects
No full textThe purpose of this session is to educate librarians and archivists about the technical aspects of the digitization process and demonstrate how deeper understanding of those aspects can be used to evaluate the appropriateness of digitization standards, project scope, quality of digitization equipment and storage needs for digitization projects involving photographs and documents. Most scholarship on archival-quality digitization has focused on either elements of digital library project management or on technical specifications and how to digitize materials. "Calculating All That Jazz" focuses on presenting a formula for calculating digital storage space based on analog still images and documents, demonstrating how deeper understanding of the technical elements of digitization in the formula applies directly to crucial project management considerations
The workshop as the work: white anti-racism organising in 1960s, 70s, and 80s US social movements
No full textThis thesis explores the rise of anti-racism workshops developed by white activists in various United States social movements from the late 1960s through the mid-1980s. The shifting ideology of the black freedom movement in the late 1960s, from integration to Black Power, transformed white activists‘ place within racial justice struggles. While recent scholarship has begun to turn its attention towards whites‘ ongoing racial justice activities, one of the most radical and widespread of these efforts is consistently overlooked: anti-racism workshops. Increasingly prevalent from the late 1960s through to the diversity-trainings explosion of the 1990s, this thesis demonstrates that these workshops had their roots in the black freedom, women‘s liberation and gay liberation movements. White activists from these movements led these workshops in order to examine white racial domination and privilege within both leftist social movements and larger US society.
Analysing case studies from the black freedom, women‘s liberation and gay liberation/rights movements, this thesis explores the foundational assumptions of anti-racism workshops. It seeks to explain how and why these efforts sought to frame race and racism as issues of knowledge and consciousness and why such efforts constituted radical praxis. It is argued that early anti-racism workshops were pedagogical projects that sought to confront the racial ignorance that structured the lives of whites in the US, including progressives and their liberation movements. This thesis draws attention to the efficacy and power of these workshops in terms of their epistemological effects, in the transformations they brought about in whites‘ understanding, or awareness, of racial realities
An improved thick-film piezoelectric material by powder blending and enhanced processing parameters
No full textThis paper details improvements of the d33 coefficient for thick-film lead zirconate titanate (PZT) layers. In particular, the effect of blending ball and attritor milled powders has been investigated. Mathematical modeling of the film structure has produced initial experimental values for powder combination percentages. A range of paste formulations between 8:1 and 2:1 ball to attritor milled PZT powders by weight have been mixed into a screen-printable paste. Each paste contains 10% by weight of lead borosilicate glass and an appropriate quantity of solvent to formulate a screen printable thixotropic paste. A d33 of 63.5 pC/N was obtained with a combination of 4:1 ball milled to attritor milled powder by weight. The improved paste combines the high d33 values of ball and the consistency of attritor milled powder. The measured d33 coefficient was further improved to 131 pC/N by increasing the furnace firing pro-file to 100
The effect of N-acetyl-aspartyl-glutamate and N-acetyl-aspartate on white matter oligodendrocytes
No full textElevations of the levels of N-acetyl-aspartyl-glutamate (NAAG) and N-acetyl-aspartate (NAA) are associated with myelin loss in the leucodystrophies Canavan's disease and Pelizaeus-Merzbacher-like disease. NAAG and NAA can activate and antagonize neuronal N-methyl-D-aspartate (NMDA) receptors, and also act on group II metabotropic glutamate receptors. Oligodendrocytes and their precursors have recently been shown to express NMDA receptors, and activation of these receptors in ischaemia leads to the death of oligodendrocyte precursors and the loss of myelin. This raises the possibility that the failure to develop myelin, or demyelination, occurring in the leucodystrophies could reflect an action of NAAG or NAA on oligodendrocyte NMDA receptors. However, since the putative subunit composition of NMDA receptors on oligodendrocytes differs from that of neuronal NMDA receptors, the effects of NAAG and NAA on them are unknown. We show that NAAG, but not NAA, evokes an inward membrane current in cerebellar white matter oligodendrocytes, which is reduced by NMDA receptor block (but not by block of metabotropic glutamate receptors). The size of the current evoked by NAAG, relative to that evoked by NMDA, was much smaller in oligodendrocytes than in neurons, and NAAG induced a rise in [Ca^{2+}]i in neurons but not in oligodendrocytes. These differences in the effect of NAAG on oligodendrocytes and neurons may reflect the aforementioned difference in receptor subunit composition. In addition, as a major part of the response in oligodendrocytes was blocked by tetrodotoxin (TTX), much of the NAAG-evoked current in oligodendrocytes is a secondary consequence of activating neuronal NMDA receptors. Six hours exposure to 1 mM NAAG did not lead to the death of cells in the white matter. We conclude that an action of NAAG on oligodendrocyte NMDA receptors is unlikely to be a major contributor to white matter damage in the leucodystrophies
Performance of a micro-engineered ultrasonic particle manipulator
No full textAn ultrasonic microfluidic particle manipulator has been modeled and its experimentally measured separation performance has been compared with the modeled results for 1 µm latex particles, and yeast particles in water
The clinical importance of white matter hyperintensities on brain magnetic resonance imaging: systematic review and meta-analysis.
No full textObjectives: To review the evidence for an association of white matter hyperintensities with risk of stroke, cognitive decline, dementia, and death.
Design: Systematic review and meta-analysis.
Data sources: PubMed from 1966 to 23 November 2009.
Study selection: Prospective longitudinal studies that used magnetic resonance imaging and assessed the impact of white matter hyperintensities on risk of incident stroke, cognitive decline, dementia, and death, and, for the meta-analysis, studies that provided risk estimates for a categorical measure of white matter hyperintensities, assessing the impact of these lesions on risk of stroke, dementia, and death.
Data extraction: Population studied, duration of follow-up, method used to measure white matter hyperintensities, definition of the outcome, and measure of the association of white matter hyperintensities with the outcome.
Data synthesis: 46 longitudinal studies evaluated the association of white matter hyperintensities with risk of stroke (n=12), cognitive decline (n=19), dementia (n=17), and death (n=10). 22 studies could be included in a meta-analysis (nine of stroke, nine of dementia, eight of death). White matter hyperintensities were associated with an increased risk of stroke (hazard ratio 3.3, 95% confidence interval 2.6 to 4.4), dementia (1.9, 1.3 to 2.8), and death (2.0, 1.6 to 2.7). An association of white matter hyperintensities with a faster decline in global cognitive performance, executive function, and processing speed was also suggested.
Conclusion: White matter hyperintensities predict an increased risk of stroke, dementia, and death. Therefore white matter hyperintensities indicate an increased risk of cerebrovascular events when identified as part of diagnostic investigations, and support their use as an intermediate marker in a research setting. Their discovery should prompt detailed screening for risk factors of stroke and dementia
Portrait of Frederick Michael Thomas, age 4 years [picture] /
No full textTitle from inscription on reverse.; Condition: Good.; Inscriptions: "Frederick Michael Thomas, age 4 years, love to all" --In ink on reverse. "N. White, Sandhurst" --Printed lower left to right.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.pic-an24154154; Exhibited:"Child's Play, Visitors Centre, National Library of Australia, 9 June 2006 - 2 October 2006 AuCNL
- …
