15,796 research outputs found
Investigation of the feasibility of sterile assembly of silver-zinc batteries
Electrical performance, bioassays, and packaging concepts evaluated in sterile assembly of silver zinc batterie
A digital algorithm for spectral deconvolution with noise filtering and peak picking: NOFIPP-DECON
Noise-filtering, peak-picking deconvolution software incorporates multiple convoluted convolute integers and multiparameter optimization pattern search. The two theories are described and three aspects of the software package are discussed in detail. Noise-filtering deconvolution was applied to a number of experimental cases ranging from noisy, nondispersive X-ray analyzer data to very noisy photoelectric polarimeter data. Comparisons were made with published infrared data, and a man-machine interactive language has evolved for assisting in very difficult cases. A modified version of the program is being used for routine preprocessing of mass spectral and gas chromatographic data
Avoiding Pandemic Fears in the Subway and Conquering the Platypus.
Metagenomics is increasingly used not just to show patterns of microbial diversity but also as a culture-independent method to detect individual organisms of intense clinical, epidemiological, conservation, forensic, or regulatory interest. A widely reported metagenomic study of the New York subway suggested that the pathogens Yersinia pestis and Bacillus anthracis were part of the "normal subway microbiome." In their article in mSystems, Hsu and collaborators (mSystems 1(3):e00018-16, 2016, http://dx.doi.org/10.1128/mSystems.00018-16) showed that microbial communities on transit surfaces in the Boston subway system are maintained from a metapopulation of human skin commensals and environmental generalists and that reanalysis of the New York subway data with appropriate methods did not detect the pathogens. We note that commonly used software pipelines can produce results that lack prima facie validity (e.g., reporting widespread distribution of notorious endemic species such as the platypus or the presence of pathogens) but that appropriate use of inclusion and exclusion sets can avoid this issue
Fast light, slow light, and phase singularities: a connection to generalized weak values
We demonstrate that Aharonov-Albert-Vaidman (AAV) weak values have a direct
relationship with the response function of a system, and have a much wider
range of applicability in both the classical and quantum domains than
previously thought. Using this idea, we have built an optical system, based on
a birefringent photonic crystal, with an infinite number of weak values. In
this system, the propagation speed of a polarized light pulse displays both
superluminal and slow light behavior with a sharp transition between the two
regimes. We show that this system's response possesses two-dimensional,
vortex-antivortex phase singularities. Important consequences for optical
signal processing are discussed.Comment: 9 pages, 4 figures, accepted in Physical Review Letters (2003
Locating the source of projectile fluid droplets
The ill-posed projectile problem of finding the source height from spattered
droplets of viscous fluid is a longstanding obstacle to accident reconstruction
and crime scene analysis. It is widely known how to infer the impact angle of
droplets on a surface from the elongation of their impact profiles. However,
the lack of velocity information makes finding the height of the origin from
the impact position and angle of individual drops not possible. From aggregate
statistics of the spatter and basic equations of projectile motion, we
introduce a reciprocal correlation plot that is effective when the polar launch
angle is concentrated in a narrow range. The vertical coordinate depends on the
orientation of the spattered surface, and equals the tangent of the impact
angle for a level surface. When the horizontal plot coordinate is twice the
reciprocal of the impact distance, we can infer the source height as the slope
of the data points in the reciprocal correlation plot. If the distribution of
launch angles is not narrow, failure of the method is evident in the lack of
linear correlation. We perform a number of experimental trials, as well as
numerical calculations and show that the height estimate is insensitive to
aerodynamic drag. Besides its possible relevance for crime investigation,
reciprocal-plot analysis of spatter may find application to volcanism and other
topics and is most immediately applicable for undergraduate science and
engineering students in the context of crime-scene analysis.Comment: To appear in the American Journal of Physics (ms 23338). Improved
readability and organization in this versio
Bubble-Driven Inertial Micropump
The fundamental action of the bubble-driven inertial micropump is
investigated. The pump has no moving parts and consists of a thermal resistor
placed asymmetrically within a straight channel connecting two reservoirs.
Using numerical simulations, the net flow is studied as a function of channel
geometry, resistor location, vapor bubble strength, fluid viscosity, and
surface tension. Two major regimes of behavior are identified: axial and
non-axial. In the axial regime, the drive bubble either remains inside the
channel or continues to grow axially when it reaches the reservoir. In the
non-axial regime the bubble grows out of the channel and in all three
dimensions while inside the reservoir. The net flow in the axial regime is
parabolic with respect to the hydraulic diameter of the channel cross-section
but in the non-axial regime it is not. From numerical modeling, it is
determined that the net flow is maximal when the axial regime crosses over to
the non-axial regime. To elucidate the basic physical principles of the pump, a
phenomenological one-dimensional model is developed and solved. A linear array
of micropumps has been built using silicon-SU8 fabrication technology, and
semi-continuous pumping across a 2 mm-wide channel has been demonstrated
experimentally. Measured variation of the net flow with fluid viscosity is in
excellent agreement with simulation results.Comment: 18 pages, 18 figures, single colum
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Preparing the sexual health workforce to deliver integrated services: is education the answer? A qualitative study exploring the impact of sexual health education on developing integrated policy and practice.
This study aimed to explore the ability of sexual health nurses working in the South West of England, to implement new learning within existing sexual health service delivery models. Drawing on Lipsky’s account of street-level bureaucracy to conceptualise policy implementation, the impact of workforce learning on the development of integrated services across this region of the United Kingdom was assessed.
In order to achieve the United Nations’ goal of universal access to sexual health, it is essential for reproductive and sexual health, including HIV provision, to integrate into a single service. This integration requires a commitment to collaboration by service commissioners and an alignment of principles and values across sexual health and contraceptive services. UK health policy has embraced this holistic agenda but moves towards integrating historically separate clinical services, has presented significant workforce development challenges and influenced policy success.
Employing a qualitative approach, the study included data from semi-structured telephone interviews and focus groups, and longitudinal data from pre- and post-intervention surveys, collected between September 2013 and September 2015. Data were collected from 88 nurses undertaking a workforce development programme and six of their service managers. Data were analysed using thematic analysis to identify consistent themes.
Nurses confirmed the role of new learning in enabling them to negotiate the political landscape but expressed frustration at their lack of agency in the integration agenda, exposing a clear dichotomy between the intentions of policy and the reality of practice. Nevertheless, using high levels of professional judgement and discretion practitioners managed the incongruence between policy and practice in order to deliver integrated services in the interests of patients. Workforce education, while essential for the transition to the delivery of integrated services, was insufficient to fulfil the sexual health agenda without a strengthening of public health
In defence of global egalitarianism
This essay argues that David Miller's criticisms of global egalitarianism do not undermine the view where it is stated in one of its stronger, luck egalitarian forms. The claim that global egalitarianism cannot specify a metric of justice which is broad enough to exclude spurious claims for redistribution, but precise enough to appropriately value different kinds of advantage, implicitly assumes that cultural understandings are the only legitimate way of identifying what counts as advantage. But that is an assumption always or almost always rejected by global egalitarianism. The claim that global egalitarianism demands either too little redistribution, leaving the unborn and dissenters burdened with their societies' imprudent choices, or too much redistribution, creating perverse incentives by punishing prudent decisions, only presents a problem for global luck egalitarianism on the assumption that nations can legitimately inherit assets from earlier generations – again, an assumption very much at odds with global egalitarian assumptions
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