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11.
Klema E. D. Pleasonton Frances Schmitt H. W. Unik J. 《IEEE transactions on nuclear science》1966,13(1):43-47
Pulse amplitude spectra for fission fragments from the spontaneous fission of Cf252 have been studied for more than 50 silicon surface-barrier detectors. Silicon resistivities ranged from 100 to 2000 Ohm-cm; spectra were obtained for several bias voltages for each detector. A search for correlations among shape parameters associated with Cf252 fragment pulse-amplitude spectra was carried out. Such correlations were, in fact, observed and are shown to be related to the pulse-height response characteristics of surface-barrier detectors for fission fragments. Some guide lines by which the quality of a fission-fragment detector may be determined from the spectrum parameters are given. 相似文献
12.
Improving protein stability in unnatural and suboptimal environmentsis a promising application of protein engineering technology.Carefully designed amino acid alterations may lead to dramaticpositive effects on the stability of proteins under highly perturbingconditions, such as in non-aqueous solvents. Applications ofbiocatalysts and proteins with specific binding capabilitiesin the chemical industry have been severely limited by constraintsplaced on the solvent environment. With the advent of convenientmethods for altering the amino acid composition and even synthesizingentirely new protein molecules, it is worthwhile to considerengineering proteins for stability in non-aqueous solvents.In order to identify the features that a protein would needfor stability in organic media, we have been studying the structureand properties of the hydrophobic protein crambin. Crambin isunique in that it is soluble and stable in very high concentrationsof polar organic solvents. Crambin and its water-soluble homologsoffer a powerful demonstration of protein engineering for non-aqueoussolvents. This paper describes the structural features thatcontribute to crambin's special properties. Based on these observationsand consideration of how non-aqueous solvents affect the interactionsimportant in protein folding, a set of rules for designing non-aqueoussolvent-stable proteins is proposed. 相似文献
13.
Cancer treatment is a fragmented and varied process, as “cancer” is really hundreds of different diseases. The “hallmarks of cancer” proposed by Hanahan and Weinberg (Cell 100(1):57–70, 2000) are a framework for viewing cancer within a common set of underlying principles—ten properties that are common to almost all cancers, allowing them to grow uncontrollably and ravage the body. We used a cellular automaton model of tumour growth paired with lattice Boltzmann methods modelling oxygen flow to simulate combination drugs targeted at knocking out pairs of hallmarks. We found that knocking out some pairs of cancer-enabling hallmarks did not prevent tumour formation, while other pairs significantly prevent tumour growth (\(p=0.0004\) using Wilcoxon signed-rank adjusted with the Bonferroni correction for multiple comparisons). This is not what would be expected from models of knocking out the hallmarks individually, as many pairs did not have an additive effect but had either no statistically significant effect or a multiplicative one. We propose that targeting certain pairs of cancer hallmarks, specifically cancers ability to induce blood vessel development paired with another cancer hallmark, could prove an effective cancer treatment option. 相似文献
14.
This paper reports on a pilot investigation into web conferencing in a distance learning module. It focuses on the perceptions and experiences of the tutors, all of whom were new to the web conferencing environment, but were experienced in online teaching. A number of web conferencing tutorials were studied through the collection of various datasets, mostly qualitative. The data were analysed by a team of researchers, informed by key literature in this area.The main findings from the pilot indicated that tutors experienced challenges in creating social presence and in managing cognitive load when dealing with multiple tasks online. There were also technical obstacles to improvisation in response to students’ emerging needs. The findings of the pilot informed the training and support provided when web tutorials were subsequently rolled out to all tutorial groups (approximately 140) in the module. Overall, experiences from the web tutorials indicate that tutors and students reacted positively to the opportunities web conferencing provides for interactive learning and teaching. 相似文献
15.
Witnessing in merging biological, social and algorithmic realities is crucial to trust, as modelled in the YUTPA framework.
Being witness and bearing witness is fundamental to human interaction. System participation in human communities of practice
challenges the notion of witnessing and therefore the ability to build trust. Nevertheless, through trial and error, people
in a variety of practices have found ways to establish the presence and develop trust in merging realities. This paper presents
the results of 20 in-depth interviews with professionals from a variety of disciplines and nations. The conclusion of cumulative
analysis is that systems do not witness themselves, but their output deeply affects the mental maps that human beings make
of each other, the world around them and their own self. Essential qualities human beings seek when being involved with other
beings are defined by granularity and reciprocity in the design of time (duration of engagement, synchronizing performance,
integrating rhythms and moments to signify), place (body sense, material interaction, emotional space and situated agency),
relation (shared meaning, engagement, reputation and use) and action (tuning, reciprocity, negotiation and quality of deeds).
By designing granular interaction in 4 dimensions, reciprocity in witnessing obtains significance and the basis for establishing
trust in a variety of presences emerges while human agency acquires potential. 相似文献
16.
Jonathan Keller Damian Carr Frances Love Paul Grabill Hieu Ngo Perumal Shanthakumaran 《Journal of Intelligent Manufacturing》2012,23(2):205-211
The US Army has launched an aggressive program to implement condition based maintenance on its rotary wing assets. Condition
Based Maintenance takes advantage of technology developments in the areas of machinery monitoring, signal processing and fault
modeling to reduce the cost of ownership through improved maintenance procedures. Documenting the reduction in maintenance
burden, cost savings and increased safety through early detection of helicopter faults is an important step in justifying
the program. This paper describes a novel technique used to detect a serious fault in the accessory section of the AH-64D
Apache main transmission. The technique determines if the primary or secondary clutch system is driving the aircraft accessories
through a tachometer speed ratio. The method has identified three aircraft operating on the secondary system allowing Army
maintenance crews to replace the affected transmissions and quickly restore the aircraft to operational status. 相似文献
17.
Silk Jennifer S.; Sessa Frances M.; Sheffield Morris Amanda; Steinberg Laurence; Avenevoli Shelli 《Canadian Metallurgical Quarterly》2004,18(1):135
This study explored the moderating effects of children's neighborhoods on the link between hostile parenting and externalizing behavior. Participants were 1st- or 2nd-grade children in an urban northeastern community. Children were administered the Parenting and Neighborhood scales of the Child Puppet Interview, and mothers completed questionnaires on neighborhood quality and parenting practices. Census tract measures of neighborhood quality and teachers' reports of children's externalizing behavior also were obtained. Results indicated that children's and mothers' perceptions of neighborhood involvement-cohesion buffered the link between hostile parenting and externalizing problems. Children's externalizing behavior was unrelated to census tract variables. Findings highlight the protective effect of neighborhood social cohesion and the utility of including young children's perspectives in research on neighborhoods and families. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
18.
ABSTRACTTotal quality management (TQM) has been increasingly accepted as a management philosophy. Criteria such as those contained in the Malcolm Baldrige National Quality Award (MBNQA) often guide TQM implementation. However, reports indicate that fully assessing TQM efforts is difficult and hiring experts to help with this task is expensive. Using survey instruments is an attractive alternative to full-scale assessment. Despite the availability of many papers covering organizational performance assessment, few instruments specifically address TQM evaluation. Furthermore, none of the TQM assessment instruments has been subjected to rigorous validation; thus, only modest confidence can be placed in results obtained from their use. This article proposes a quick and cost-effective instrument that is a simple questionnaire designed to assist organizations in conducting self-evaluations of their TQM programs. The proposed instrument is based on the seven categories of the MBNQA criteria and was developed in cooperation with the Excellence in Missouri Foundation, which administers the Missouri Quality Award (MQA). This article highlights how questionnaire results can be used to guide further TQM implementation efforts. 相似文献
19.
Frances Richards 《Journal of Failure Analysis and Prevention》2013,13(6):653-657
From aviation accidents to pipeline explosions, the National Transportation Safety Board is often called to determine probable cause and make safety recommendations, as they did in the aftermath of the 2010 San Bruno pipeline explosion. 相似文献
20.