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排序方式: 共有1017条查询结果,搜索用时 15 毫秒
21.
Zeyad A. Almutairi Tomasz Glawdel Carolyn L. Ren David A. Johnson 《Microfluidics and nanofluidics》2009,6(2):241-251
This study presents a new Y-channel design for measuring the zeta potential and surface conductance of a solid-liquid pairing
using the current monitoring technique. The new design improves the throughput and reliability of the testing apparatus since
the displacement between two solutions can be repeated many times without interfering with the experiments. It also increases
the accuracy of the measurement by producing sharper start and end transitions for the current–time plot of the solution displacement
process. In this design, efforts have been made to minimize the effects of electrolysis, Joule heating and undesired pressure
driven flow on the measurements. An improvement on the current–time slope analysis is also presented. The Y-channel design
was validated by comparing zeta potential measurements to published results. The zeta potential of several biological buffers
relevant to the microfluidic community in plasma treated PDMS/PDMS and PDMS/Glass microchannels are presented. Preliminary
studies of surface conductivity measurements using the Y-channel design were also conducted and are briefly discussed. 相似文献
22.
Identifying and integrating patient and caregiver perspectives for clinical practice guidelines on the screening and management of infectious microorganisms in hemodialysis units 下载免费PDF全文
Hilary M. Miller Allison Tong David J. Tunnicliffe Denise Campbell Jule Pinter Robert J. Commons Eugene Athan Jonathan C. Craig Nicole Gilroy Julianne Green Belinda Henderson Martin Howell Rhonda L. Stuart Carolyn van Eps Muh Geot Wong Janak de Zoysa Meg J. Jardine 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(2):213-223
23.
Carolyn L. Kane 《History of Photography》2016,40(2):129-145
Like past avant-garde movements, glitch and noise in the twenty-first century are used to reveal the materiality of the medium. But instead of providing insight or clarity into the politics or social conditions of a technology, they demarcate broader conditions of opacity and blockage, contributing to what Jodi Dean has called ‘communicative capitalism’. The work of German photographer Thomas Ruff alongside the Düsseldorf School, New Photography and JPEG technology are used in this article to illustrate this tendency as a move away from meaning and toward visual noise and communicative breakdown. I use three core analytic registers: the deliberate failure to adhere to visual norms, communicative failure and machine failure and breakdown. Ruff’s work uses visual noise as art to at once reaffirm pervasive conditions of breakdown, failure and decline in high-tech global capitalism, while simultaneously providing a temporary reprieve from these conditions through an emergent form of visual beauty. 相似文献
24.
Reconstructing boundaries along material interfaces from volume fractions is a difficult problem, especially because the under‐resolved nature of the input data allows for many correct interpretations. Worse, algorithms widely accepted as appropriate for simulation are inappropriate for visualization. In this paper, we describe a new algorithm that is specifically intended for reconstructing material interfaces for visualization and analysis requirements. The algorithm performs well with respect to memory footprint and execution time, has desirable properties in various accuracy metrics, and also produces smooth surfaces with few artifacts, even when faced with more than two materials per cell. 相似文献
25.
Leonard Rusli Anthony Luscher Carolyn Sommerich 《International Journal of Industrial Ergonomics》2010,40(6):618-628
The purpose of this study was to investigate the tactile feedback of snap-fit fasteners when used in manual assembly. An important aspect of this assembly process is the assembler’s ability to perceive the snap-fit’s engagement. This sensing of engagement yields a high level of confidence that assembly is both complete and secure. Force and tactile feedback are critical elements in this process. Many snap-fits are used in conjunction with sealing elements that produce a constant force that remains in effect after snap-fit assembly is completed. The effect of sealing element preload magnitude and stiffness was studied using a test station, force deflection measurements, and jury pool data. A low value of preload with low stiffness was determined to be most favorable in terms of force and tactile feedback, with no preload only slightly less favorable. In order to sense the engagement signal of the catch, some resistance to assembly was found to be beneficial. A dimensionless term called “engagement signal-to-hold-force ratio” is proposed as an additional way of rating the effect of assembly forces for snap-fits. It was found that higher signal-to-hold-force ratio, as well as higher values of engagement signal, corresponded to higher confidence of assembly among experimental subjects.
Relevance to Industry
In the automotive industry, force and tactile feedback are essential for sensing the full engagement of snap-fit parts during the assembly of critical components, such as electrical and fuel system interconnects. Both the design of the snap-fit and the presence or absence of preload will affect force and tactile feedback. Many of these applications require the compression of an elastic gasket with a preload needed for air, fuel, or electrical isolation. Preload and preload stiffness factors are examined in this paper with the aim of achieving a better understanding of these effects so that snap-fit confidence of assembly and assembly robustness can be enhanced in industrial settings. 相似文献26.
Health care providers and governments are under pressure to maintain and improve the quality of care to an increasing volume
of critical care patients at either end of the life cycle, namely premature and ill term babies together with the elderly.
The provision of a service of critical care utilizing real time service-oriented architectures has the potential to enable
clinicians to be supported in the care of a greater number patients that are, perhaps more importantly, located elsewhere
to their intensive care units. This paper presents a review of recent research in the application of computing and IT to support
the service of critical care and determines the trends and challenges for the application of real time service-oriented architectures
within the domain. It then presents some case study–based research on the design of a service-oriented architecture-based
approach to support two aspects of critical care namely elderly care and neonatal intensive care to provide further context
to trends and opportunities. 相似文献
27.
28.
James L. Kerwin Joanna K. MacKichan Melinda J. Semon Alison M. Wiens Carolyn C. DeRose Jessica J. Torvik 《Lipids》1996,31(11):1179-1188
Lagenidium giganteum, a facultative parasite of mosquito larvae, cannot synthesize sterols, and requires an exogenous source of these lipids in
order to enter its reproductive cycle. This parasite grows vegetatively in the absence of sterols, but requires cholesterol
or structurally related compounds to produce motile zoospores, which are the only stage capable of infecting mosquitoes. Sterols
structurally related to cholesterol and some steryl esters inhibited the activity ofL. giganteum phospholipase A2 (PLA2), an enzyme that hydrolyzes fatty acids from thesn-2 position of glycerophospholipids. Sterols that induce reproduction inhibitedL. giganteum PLA2 activity, while sterols and steroids that do not support sporulation had minimal effect. Most steryl esters had no effect
on enzyme activity, but cholesteryl arachidonate (CA) was a potent inhibitor of parasite PLA2. Not all enzymes partly purified using a DEAE-Sephacel column were affected by these lipids, demonstrating selective inhibition
of specific enzymes. Potency was enhanced by up to several orders of magnitude if epoxy fatty acids were esterified to the
cholesterol nucleus. The steryl ester pool was dynamic during morphogenesis, and the fatty acid composition of the steryl
esters did not mimic total cell or membrane (glycerophospholipid) fatty acid composition asL. giganteum proceeded through its growth cycle. Synthesis of CA and monoepoxy CA by the parasite was confirmed using electrospray mass
spectrometry and collision-induced dissociation. Steryl derivatives selectively inhibited PLA2 enzymes from bovine pancreas, snake venom, and human cytoplasmic 85-kDa PLA2. 相似文献
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30.
The objectives of an organization in combination with the formal policy together underpin the strategic direction that any organization will take. We all know that security begins with policy – in other words the rules of play. If policy is sound then the appropriate security measures can be implemented to protect the activities required to achieve the stated objectives as well as maintain the information assurance requirements – availability, integrity, authentication, confidentiality and non-repudiation. 相似文献