2,230 research outputs found

    Capabilities of Earth-based radar facilities for near-Earth asteroid observations

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    We evaluated the planetary radar capabilities at Arecibo, the Goldstone 70-m DSS-14 and 34-m DSS-13 antennas, the 70-m DSS-43 antenna at Canberra, the Green Bank Telescope, and the Parkes Radio Telescope in terms of their relative sensitivities and the number of known near-Earth asteroids (NEAs) detectable per year in monostatic and bistatic configurations. In the 2015 calendar year, monostatic observations with Arecibo and DSS-14 were capable of detecting 253 and 131 NEAs respectively, with signal-to-noise ratios (SNRs) greater than 30/track. Combined, the two observatories were capable of detecting 276 NEAs. Of these, Arecibo detected 77 and Goldstone detected 32, or 30% and 24% the numbers that were possible. The two observatories detected an additional 18 and 7 NEAs respectively, with SNRs of less than 30/track. This indicates that a substantial number of potential targets are not being observed. The bistatic configuration with DSS-14 transmitting and the Green Bank Telescope receiving was capable of detecting about 195 NEAs, or ~50% more than with monostatic observations at DSS-14. Most of the detectable asteroids were targets of opportunity that were discovered less than 15 days before the end of their observing windows. About 50% of the detectable asteroids have absolute magnitudes > 25, which corresponds diameters < ~30 m.Comment: 12 pages, 7 figures, Accepted to A

    Method of fabricating a nanochannel system for DNA sequencing and nanoparticle characterization

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    A process for fabricating a nanochannel system using a combination of microelectromechanical system (MEMS) microfabrication techniques, atomic force microscopy (AFM) nanolithography, and focused ion beam (FIB). The nanochannel system, fabricated on either a glass or silicon substrate, has channel heights and widths on the order of single to tens of nanometers. The channel length is in the micrometer range. The nanochannel system is equipped with embedded micro and nanoscale electrodes, positioned along the length of the nanochannel for electron tunneling based characterization of nanoscale particles in the channel. Anodic bonding is used to cap off the nanochannel with a cover chip

    Designing industrial strategy for a low carbon transformation

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    The recent re-emergence of industrial policy as a legitimate pursuit of governments in Europe and the US has the potential to open up a new realm of policy action for climate change mitigation. This would aim to align efforts to secure national industrial opportunities with the development of low carbon industrial systems, so as to generate both socio-economic and environmental benefits. The paper discusses the role of low carbon industrial strategy in seeking to do this, thereby accelerating transitions to a low carbon economy. It sets out the elements of a more systemic low carbon industrial strategy, including providing a mission-oriented and learning-based approach, drawing on and combining insights from neo-Schumpeterian and ecological economics perspectives

    Transferring elements of a density matrix

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    We study restrictions imposed by quantum mechanics on the process of matrix elements transfer. This problem is at the core of quantum measurements and state transfer. Given two systems \A and \B with initial density matrices λ\lambda and rr, respectively, we consider interactions that lead to transferring certain matrix elements of unknown λ\lambda into those of the final state r~{\widetilde r} of \B. We find that this process eliminates the memory on the transferred (or certain other) matrix elements from the final state of \A. If one diagonal matrix element is transferred, r~aa=λaa{\widetilde r}_{aa}=\lambda_{aa}, the memory on each non-diagonal element λa=̞b\lambda_{a\not=b} is completely eliminated from the final density operator of \A. Consider the following three quantities \Re \la_{a\not =b}, \Im \la_{a\not =b} and \la_{aa}-\la_{bb} (the real and imaginary part of a non-diagonal element and the corresponding difference between diagonal elements). Transferring one of them, e.g., \Re\tir_{a\not = b}=\Re\la_{a\not = b}, erases the memory on two others from the final state of \A. Generalization of these set-ups to a finite-accuracy transfer brings in a trade-off between the accuracy and the amount of preserved memory. This trade-off is expressed via system-independent uncertainty relations which account for local aspects of the accuracy-disturbance trade-off in quantum measurements.Comment: 9 pages, 2 table

    Method of fabricating a nanochannel system for DNA sequencing and nanoparticle characterization

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    A process for fabricating a nanochannel system using a combination of microelectromechanical system (MEMS) microfabrication techniques, atomic force microscopy (AFM) nanolithography, and focused ion beam (FIB). The nanochannel system, fabricated on either a glass or silicon substrate, has channel heights and widths on the order of single to tens of nanometers. The channel length is in the micrometer range. The nanochannel system is equipped with embedded micro and nanoscale electrodes, positioned along the length of the nanochannel for electron tunneling based characterization of nanoscale particles in the channel. Anodic bonding is used to cap off the nanochannel with a cover chip

    Concert recording 2013-04-20a

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    [Track 01]. Moving air / Nigel Westlake -- [Track 02]. Violin sonata no. 1 in G minor. Fuga / J.S. Bach -- [Track 03]. Merlin. Beyond the faint edge of the world ; [Track 04] Time\u27s way / Andrew Thomas -- [Track 05] Fear cage / Kirk J. Gay -- [Track 06]. Among the thorns / Sean Sweeden -- [Track 07]. String quartet no. 16 in F major, op. 135. Lento assai, cantate e tranquillo ; Vivace / Ludwig van Beethoven, arranged by Sean Sweeden

    Best practice in maternity and mental health services? A service user's perspective

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    The birth of a baby is a much-anticipated event. However, for some women diagnosed with mental health needs their pregnancy and potential parenting are seen as problematic. Even if the child is much wanted and the pregnancy is planned, this news can be greeted with uncertainty and concern by the medical and maternity services. They need to plan how they will “manage” the mother’s behavior and protect the child from her potentially risky behavior. Most literature focuses on the negative impact that mental illness has on the development of the baby and the young child.1,2 It emphasizes the risk factors that specific mental illness diagnoses might have and the mother’s potential for abuse of her offspring.3,4 However, qualitative literature, which has been undertaken with mothers with a diagnosis, introduces a different perspective. Indeed fear of removal of the child,5 a perception of the intrusiveness of services5,6 and the stigma of mental ill health dominate their contact with mental health and child development services.7,8 In this article, I use a synthesis of first person narrative and research to explore the experience of being a both a pregnant woman and new mother who has a diagnosis of schizophrenia and my relationship with both mental health and maternity services. I describe the best practice care I received from the mental health services and the reactive, diagnosis led service that was set in motion by the maternity services. I intertwine the 2 elements of research and experience to explore how service provision can be more effective when it is built on a model that promotes shared decision-making and a sense of trust with shared responsibility. I seek to challenge the process led nature of care that leads professionals to become unquestioning actors in a game of risk management and discuss how practitioners can work with people as individuals. In this discussion, I highlight the importance of the strengths led approach, which is underpinned by a belief in clients’ capabilities and strengths, not their deficits

    Effect of pulsed delivery and bouillon base on saltiness and bitterness perceptions of salt delivery profiles partially substituted with KCl

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    Reducing salt levels in processed food is an important target for a growing numbers of food manufacturers. The effects of pulsed delivery (Dynataste) and bouillon base on saltiness and bitterness perception of partially substituted solutions (KCl) were investigated. Pulsed delivery did not enhance salt perception and resulted in greater Overall Bitterness Scores for the same level of substitution with KCl. The presence of the bouillon base masked to a certain extent the loss of saltiness induced by the substitution and resulted in lower Overall Bitterness Scores of the substituted profiles

    Testing KiDS cross-correlation redshifts with simulations

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    Measuring cosmic shear in wide-field imaging surveys requires accurate knowledge of the redshift distribution of all sources. The clustering-redshift technique exploits the angular cross-correlation of a target galaxy sample with unknown redshifts and a reference sample with known redshifts. It represents an attractive alternative to colour-based methods of redshift calibration. Here we test the performance of such clustering redshift measurements using mock catalogues that resemble the Kilo-Degree Survey (KiDS). These mocks are created from the MICE simulation and closely mimic the properties of the KiDS source sample and the overlapping spectroscopic reference samples. We quantify the performance of the clustering redshifts by comparing the cross-correlation results with the true redshift distributions in each of the five KiDS photometric redshift bins. Such a comparison to an informative model is necessary due to the incompleteness of the reference samples at high redshifts. Clustering mean redshifts are unbiased at |Δz|< 0.006 under these conditions. The redshift evolution of the galaxy bias of the reference and target samples represents one of the most important systematic errors when estimating clustering redshifts. It can be reliably mitigated at this level of precision using auto-correlation measurements and self-consistency relations, and will not become a dominant source of systematic error until the arrival of Stage-IV cosmic shear surveys. Using redshift distributions from a direct colour-based estimate instead of the true redshift distributions as a model for comparison with the clustering redshifts increases the biases in the mean to up to |Δz|∌0.04. This indicates that the interpretation of clustering redshifts in real-world applications will require more sophisticated (parameterised) models of the redshift distribution in the future. If such better models are available, the clustering-redshift technique promises to be a highly complementary alternative to other methods of redshift calibration
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