879 research outputs found

    THE BEHAVIOR OF ELECTROLYTIC SOLUTIONS AT ELEVATED TEMPERATURES AS DERIVED FROM CONDUCTANCE MEASUREMENTS

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    Methods and techniques for measuring the conductances of reactor solutions at elevated temperatures and to interpret the results with electrolytic solution theories are discussed. Criteria applied to room-temperature conductances for determining complete ionization of 1-1 electrolytes were applied to the Noyes high-temperature conductance data obtdined on NaCl, HCl, KCl, NaOH, AgNO3, and H/sub 3/PO/sub 4/ solutions. lt was found that the first four electrolytes behave as strong electrolytes up through temperatures of 218, 218, 281, and 156 deg C, respectively. Application of the Bjerrum theory showed that, somewhat above each of these temperatures, these electrolytes begin to associate by ion-pair formation. H/sub 3/PO/sub 4/ solutions associated at room temperature and above. AgNO/sub 3/ solutions appeared to asscciate at all temperatures. The equivalent conductances and infinite dilution and the dissociation constants for each of the electrolytes were calculatsd. An apparatus was constructed and measurements were made on the conductances of LiOH and NH/sub 4/OH solutions over the temperature range of 100 to 520 deg F. Equivalent conductances at infinite dilution were calculated. The pH of reactor coolants using LiOH or NH/sub 4/OH was calculated from the disscciation constants for water, LiOH, and NH/sub 4/OH at elevated temperatures. (auth

    Fit for work? Health, employability and challenges for the UK welfare reform agenda

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    This article introduces a special issue of Policy Studies entitled ā€œFit for work? Health, employability and challenges for the UK welfare reform agendaā€. Growing from a shared concern over the need to expand the evidence base around the processes that led to large numbers of people claiming disability benefits in the UK, it brings together contributions from leading labour market and social policy researchers providing evidence and commentary on major reforms to Incapacity Benefit (IB) in the UK. This special issue address three key questions: what are the main causes of the long-term rise in the number of people claiming IBs; what will reduce the number of claimants; and what is likely to deliver policy effectively and efficiently? This introduction first explains and examines the challenges to reforms to IB in the UK, and then, in conclusion, highlights the answers to the previous three questions ā€“ first, labour market restructuring and marginalisation have driven the rise in numbers claiming IBs. Second, economic regeneration in the Britainā€™s less prosperous areas coupled with intensive and sustained supply-side support measures will bring numbers down. Third, delivery need to be flexible and tailored to individual needs and needs to be able to access local and expert knowledge in a range of organisations, including Job Centre Plus, the NHS as well as the private and voluntary sectors

    Microflare Heating of a Solar Active Region Observed with NuSTAR, Hinode/XRT, and SDO/AIA

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    NuSTAR is a highly sensitive focusing hard X-ray (HXR) telescope and has observed several small microflares in its initial solar pointings. In this paper, we present the first joint observation of a microflare with NuSTAR and Hinode/XRT on 2015 April 29 at ~11:29 UT. This microflare shows heating of material to several million Kelvin, observed in Soft X-rays (SXRs) with Hinode/XRT, and was faintly visible in Extreme Ultraviolet (EUV) with SDO/AIA. For three of the four NuSTAR observations of this region (pre-, decay, and post phases) the spectrum is well fitted by a single thermal model of 3.2-3.5 MK, but the spectrum during the impulsive phase shows additional emission up to 10 MK, emission equivalent to A0.1 GOES class. We recover the differential emission measure (DEM) using SDO/AIA, Hinode/XRT, and NuSTAR, giving unprecedented coverage in temperature. We find the pre-flare DEM peaks at ~3 MK and falls off sharply by 5 MK; but during the microflare's impulsive phase the emission above 3 MK is brighter and extends to 10 MK, giving a heating rate of about 2.5Ɨ10252.5 \times 10^{25} erg sāˆ’1^{-1}. As the NuSTAR spectrum is purely thermal we determined upper-limits on the possible non-thermal bremsstrahlung emission. We find that for the accelerated electrons to be the source of the heating requires a power-law spectrum of Ī“ā‰„7\delta \ge 7 with a low energy cut-off Ecā‰²7E_{c} \lesssim 7 keV. In summary, this first NuSTAR microflare strongly resembles much more powerful flares.Comment: Accepted for publication in ApJ. 14 pages with 12 figures and 1 tabl

    Profiling Autism and Attention Deficit Hyperactivity Disorder Traits in Children with SYNGAP1-Related Intellectual Disability

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    SYNGAP1-related ID is a genetic condition characterised by global developmental delay and epilepsy. Individuals with SYNGAP1-related ID also commonly show differences in attention and social communication/interaction and frequently receive additional diagnoses of Autism Spectrum Disorder (ASD) or Attention Deficit Hyperactivity Disorder (ADHD). We thus set out to quantify ASD and ADHD symptoms in children with this syndrome. To assess ASD and ADHD, parents and caregivers of a child with SYNGAP1-related ID (Nā€‰=ā€‰34) or a typically developing control (Nā€‰=ā€‰21) completed the Social Responsiveness Scale-2, the Social Communication Questionnaire with a subset of these also completing the Conners-3. We found that those with SYNGAP1-related ID demonstrated higher levels of autistic traits on both the SRS and SCQ than typically developing controls. On the SRS, those with SYNGAP1-related ID scored highest for restricted repetitive behaviours, and were least impaired in social awareness. On the Conners-3, those with SYNGAP1-related ID also showed a high prevalence of ADHD traits, with scores demonstrating difficulties with peer relations but relatively low occurrence of symptoms for DSM-5 conduct disorder and DSM-5 oppositional defiant disorder. Hierarchical clustering analysis highlighted distinct SYNGAP1-related ID subgroups for both ASD and ADHD traits. These findings provide further characterisation of the SYNGAP1-related ID behavioural phenotype, guiding diagnosis, assessment and potential interventions.</p

    Using Mixed-Methods to Examine Factors that Influence Exercise Prescription from Healthcare Providers: A Community-Engaged Research Project

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    Background: The American College of Sports Medicine\u27s Exercise is Medicine initiative supports promotion of physical activity by health care providers (HCPs). Exercise is Medicine recommends HCPs utilize strategies such as exercise prescriptions to increase and promote regular exercise and referrals to community-based exercise facilities (ExRx+). Research is needed to identify factors that will increase African-American patients\u27 ExRx+ engagement since little is known about factors that serve as facilitators or barriers to adherence. Aims: Using a community-engaged participatory research approach, the aims are to: 1) examine individual, interpersonal and environmental factors associated with ExRx+ adherence and 2) explore barriers and facilitators related to the referral process that are associated with ExRx+ adherence. Setting: Healthworks Community Fitness, a non-profit women\u27s fitness facility located in Dorchester, MA. Healthworks is the only gym in the Boston metro area which allows patients to exchange ExRx+ for a 3-month gym membership. Methods: Based on a socio-ecological framework, the mixed-methods protocol includes qualitative and quantitative methods implemented sequentially in two phases to explore factors associated with ExRx+ adherence. Adherence will be operationally defined as: 1) activation: patient redeems the ExRx+ for membership and 2) utilization: attendance during the 3 month membership. Quantitative data will focus on the patient\u27s individual (i.e, body mass index, self-efficacy) interpersonal (i.e, social support), and environmental (i.e, walkability, transportation) levels. Qualitative data will involve one-on-one interviews with patients, HCPs and Healthworks staff exploring facilitators and barriers to ExRx+ adherence. Results will inform the development of a culturally tailored intervention to promote ExRx+ adherence

    The Completely Hackable Amateur Radio Telescope (CHART) Project

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    We present the Completely Hackable Amateur Radio Telescope (CHART), a project that provides hands-on radio instrumentation and design experience to undergraduates while bringing accessible radio astronomy experiments to high school students and teachers. Here we describe a system which can detect 21-cm emission from the Milky Way which is optimized for cost and simplicity of construction. Software, documentation, and tutorials are all completely open source to improve the user experience and facilitate community involvement. We demonstrate the design with several observations which we compare with state-of-the-art surveys. The system is shown to detect galactic 21-cm emission in both rural and urban settings

    Muscle Activated 3D Printed Prosthetic Arm

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    Due to the rapid growth of children and the cost of myoelectric technology, children are not given the same opportunities to use myoelectric prosthetics as adults. The Muscle Activated Prosthesis (MAP) team seeks to reconcile this by creating an affordable, trans-radial, myoelectric prosthesis that utilizes the flexibility of 3D printing technology for a fourteen-year-old congenital amputee named Lily. The MAP team has completed the design and prototype of a myoelectric prosthesis with a material cost of approximately 1,000asopposedtothe1,000 as opposed to the 10,000-$20,000 cost of clinically accepted myoelectric prosthetic upper limbs. The 3D printed prosthetic arm prototype incorporates electromyography (EMG) electrodes, a motor and tendon system, an open-source prosthetic hand design, a custom printed circuit board (PCB), and lithium-ion battery power. The opening and closing of the prosthetic hand is controlled by the myoelectric signals from the userā€™s forearm contractions which can be tested by the team using our adaptive prosthetic attachment. All these components result in an affordable prosthetic that has the potential for customization and adaptation to different sized limbs. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1009/thumbnail.jp

    First NuSTAR Limits on Quiet Sun Hard X-Ray Transient Events

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    We present the first results of a search for transient hard X-ray (HXR) emission in the quiet solar corona with the \textit{Nuclear Spectroscopic Telescope Array} (\textit{NuSTAR}) satellite. While \textit{NuSTAR} was designed as an astrophysics mission, it can observe the Sun above 2~keV with unprecedented sensitivity due to its pioneering use of focusing optics. \textit{NuSTAR} first observed quiet Sun regions on 2014 November 1, although out-of-view active regions contributed a notable amount of background in the form of single-bounce (unfocused) X-rays. We conducted a search for quiet Sun transient brightenings on time scales of 100 s and set upper limits on emission in two energy bands. We set 2.5--4~keV limits on brightenings with time scales of 100 s, expressed as the temperature T and emission measure EM of a thermal plasma. We also set 10--20~keV limits on brightenings with time scales of 30, 60, and 100 s, expressed as model-independent photon fluxes. The limits in both bands are well below previous HXR microflare detections, though not low enough to detect events of equivalent T and EM as quiet Sun brightenings seen in soft X-ray observations. We expect future observations during solar minimum to increase the \textit{NuSTAR} sensitivity by over two orders of magnitude due to higher instrument livetime and reduced solar background.Comment: 11 pages, 7 figures; accepted for publication in The Astrophysical Journa

    Vegetation response to invasive Tamarix control in southwestern U.S. rivers: a collaborative study including 416 sites

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    Most studies assessing vegetation response following control of invasive Tamarix trees along southwestern U.S. rivers have been small in scale (e.g., river reach), or at a regional scale but with poor spatial-temporal replication, and most have not included testing the effects of a now widely used biological control. We monitored plant composition following Tamarix control along hydrologic, soil, and climatic gradients in 244 treated and 172 reference sites across six U.S. states. This represents the largest comprehensive assessment to date on the vegetation response to the four most common Tamarix control treatments. Biocontrol by a defoliating beetle (treatment 1) reduced the abundance of Tamarix less than active removal by mechanically using hand and chain-saws (2), heavy machinery (3) or burning (4). Tamarix abundance also decreased with lower temperatures, higher precipitation, and follow-up treatments for Tamarix resprouting. Native cover generally increased over time in active Tamarix removal sites, however, the increases observed were small and was not consistently increased by active revegetation. Overall, native cover was correlated to permanent stream flow, lower grazing pressure, lower soil salinity and temperatures, and higher precipitation. Species diversity also increased where Tamarix was removed. However, Tamarix treatments, especially those generating the highest disturbance (burning and heavy machinery), also often promoted secondary invasions of exotic forbs. The abundance of hydrophytic species was much lower in treated than in reference sites, suggesting that management of southwestern U.S. rivers has focused too much on weed control, overlooking restoration of fluvial processes that provide habitat for hydrophytic and floodplain vegetation. These results can help inform future management of Tamarix-infested rivers to restore hydrogeomorphic processes, increase native biodiversity and reduce abundance of noxious species
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