4,602 research outputs found
Alien Registration- Barter, Ada M. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/24016/thumbnail.jp
Influence of anodizing process on fatigue life of a machined aluminium alloy
In order to investigate the coupled effects of machining and anodizing processes on fatigue life of alloy 7010-T7451, a series of rotating bending fatigue tests were conducted at 60Hz. In the as machined condition, test results showed that fatigue life is surface roughness dependent and that fatigue life decreases with an increase in surface roughness and this effect is found to be more pronounced in high cycle fatigue where major portion of fatigue life is consumed in nucleating the cracks. Effects of pretreatments, like degreasing and pickling employed prior to anodizing, on fatigue life of the given alloy were also studied. Results demonstrated that degreasing showed no change in fatigue life while pickling had negative impact on fatigue life of specimens. The small decrease in fatigue life of anodized specimens as compare to pickled specimens is attributed to brittle and microcracking of the coating. Scanning electron microscopic (SEM) examination revealed multi-site crack initiation for the pickled and anodized specimens. SEM examination showed that pickling solution attacked the grain boundaries and intermetallic inclusions present on the surface resulting in pits formation. These pits are of primary concern with respect to accelerated fatigue crack nucleation and subsequent anodized coating formation
Photonic qubits, qutrits and ququads accurately prepared and delivered on demand
Reliable encoding of information in quantum systems is crucial to all
approaches to quantum information processing or communication. This applies in
particular to photons used in linear optics quantum computing (LOQC), which is
scalable provided a deterministic single-photon emission and preparation is
available. Here, we show that narrowband photons deterministically emitted from
an atom-cavity system fulfill these requirements. Within their 500 ns coherence
time, we demonstrate a subdivision into d time bins of various amplitudes and
phases, which we use for encoding arbitrary qu-d-its. The latter is done
deterministically with a fidelity >95% for qubits, verified using a newly
developed time-resolved quantum-homodyne method.Comment: 5 pages, 4 figure
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Tuberculosis and poverty: the contribution of patient costs in sub-Saharan Africa – a systematic review
Background: Tuberculosis (TB) is known to disproportionately affect the most economically disadvantaged strata of society. Many studies have assessed the association between poverty and TB, but only a few have assessed the direct financial burden TB treatment and care can place on households. Patient costs can be particularly burdensome for TB-affected households in sub-Saharan Africa where poverty levels are high; these costs include the direct costs of medical and non-medical expenditures and the indirect costs of time utilizing healthcare or lost wages. In order to comprehensively assess the existing evidence on the costs that TB patients incur, we undertook a systematic review of the literature. Methods: PubMed, EMBASE, Science Citation Index, Social Science Citation Index, EconLit, Dissertation Abstracts, CINAHL, and Sociological Abstracts databases were searched, and 5,114 articles were identified. Articles were included in the final review if they contained a quantitative measure of direct or indirect patient costs for treatment or care for pulmonary TB in sub-Saharan Africa and were published from January 1, 1994 to Dec 31, 2010. Cost data were extracted from each study and converted to 2010 international dollars (I1 to almost I$600 or from a small fraction of mean monthly income for average annual income earners to over 10 times average annual income for income earners in the income-poorest 20% of the population. Out of the eleven types of TB patient costs identified in this review, the costs for hospitalization, medication, transportation, and care in the private sector were largest. Conclusion: TB patients and households in sub-Saharan Africa often incurred high costs when utilizing TB treatment and care, both within and outside of Directly Observed Therapy Short-course (DOTS) programs. For many households, TB treatment and care-related costs were considered to be catastrophic because the patient costs incurred commonly amounted to 10% or more of per capita incomes in the countries where the primary studies included in this review were conducted. Our results suggest that policies to decrease direct and indirect TB patient costs are urgently needed to prevent poverty due to TB treatment and care for those affected by the disease
Optically trapped atom interferometry using the clock transition of large Rb-87 Bose-Einstein condensates
We present a Ramsey-type atom interferometer operating with an optically
trapped sample of 10^6 Bose-condensed Rb-87 atoms. The optical trap allows us
to couple the |F =1, mF =0>\rightarrow |F =2, mF =0> clock states using a
single photon 6.8GHz microwave transition, while state selective readout is
achieved with absorption imaging. Interference fringes with contrast
approaching 100% are observed for short evolution times. We analyse the process
of absorption imaging and show that it is possible to observe atom number
variance directly, with a signal-to-noise ratio ten times better than the
atomic projection noise limit on 10^6 condensate atoms. We discuss the
technical and fundamental noise sources that limit our current system, and
outline the improvements that can be made. Our results indicate that, with
further experimental refinements, it will be possible to produce and measure
the output of a sub-shot-noise limited, large atom number BEC-based
interferometer.
In an addendum to the original paper, we attribute our inability to observe
quantum projection noise to the stability of our microwave oscillator and
background magnetic field. Numerical simulations of the Gross-Pitaevskii
equations for our system show that dephasing due to spatial dynamics driven by
interparticle interactions account for much of the observed decay in fringe
visibility at long interrogation times. The simulations show good agreement
with the experimental data when additional technical decoherence is accounted
for, and suggest that the clock states are indeed immiscible. With smaller
samples of 5 \times 10^4 atoms, we observe a coherence time of {\tau} =
(1.0+0.5-0.3) s.Comment: 22 pages, 6 figures Addendum: 11 pages, 6 figure
Pornography, sexual coercion and abuse and sexting in young people’s intimate relationships: A European study
New technology has made pornography increasingly accessible to young people, and a growing evidence base has identified a relationship between viewing pornography and violent or abusive behavior in young men. This article reports findings from a large survey of 4,564 young people aged 14 to 17 in five European countries which illuminate the relationship between regular viewing of online pornography, sexual coercion and abuse and the sending and receiving of sexual images and messages, known as “sexting.” In addition to the survey, which was completed in schools, 91 interviews were undertaken with young people who had direct experience of interpersonal violence and abuse in their own relationships. Rates for regularly viewing online pornography were very much higher among boys and most had chosen to watch pornography. Boys’ perpetration of sexual coercion and abuse was significantly associated with regular viewing of online pornography. Viewing online pornography was also associated with a significantly increased probability of having sent sexual images/messages for boys in nearly all countries. In addition, boys who regularly watched online pornography were significantly more likely to hold negative gender attitudes. The qualitative interviews illustrated that, although sexting is normalized and perceived positively by most young people, it has the potential to reproduce sexist features of pornography such as control and humiliation. Sex and relationships education should aim to promote a critical understanding of pornography among young people that recognizes its abusive and gendered values
Controlling fatigue crack paths for crack surface marking and growth investigations
While it is well known that fatigue crack growth in metals that display confined slip, such as high strength aluminium alloys, develop crack paths that are responsive to the loading direction and the local microstructural orientation, it is less well known that such paths are also responsive to the loading history. In these materials, certain loading sequences can produce highly directional slip bands ahead of the crack tip and by adjusting the sequence of loads, distinct fracture surface features or progression marks, even at very small crack depths can result. Investigating the path a crack selects in fatigue testing when particular combinations of constant and variable amplitude load sequences are applied is providing insight into crack growth. Further, it is possible to design load sequences that allow very small amounts of crack growth to be measured, at very small crack sizes, well below the conventional crack growth threshold in the aluminium alloy discussed here. This paper reports on observations of the crack path phenomenon and a novel test loading method for measuring crack growth rates for very small crack depths in aluminium alloy 7050-T7451 (an important aircraft primary structural material). The aim of this work was to firstly generate short- crack constant amplitude growth data and secondly, through the careful manipulation of the applied loading, to achieve a greater understanding of the mechanisms of fatigue crack growth in the material being investigated. A particular focus of this work is the identification of the possible sources of crack growth retardation and closure in these small cracks. Interpreting these results suggests a possible mechanism for why small fatigue crack growth through this material under variable amplitude loading is faster than predicted from models based on constant amplitude data alone
Effects of dalcetrapib in patients with a recent acute coronary syndrome
In observational analyses, higher levels of high-density lipoprotein (HDL) cholesterol have been associated with a lower risk of coronary heart disease events. However, whether raising HDL cholesterol levels therapeutically reduces cardiovascular risk remains uncertain. Inhibition of cholesteryl ester transfer protein (CETP) raises HDL cholesterol levels and might therefore improve cardiovascular outcomes
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