8,194 research outputs found

    Test results of JPL LiSOCl sub 2 cells

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    In the development of high rate Li-SO-Cl2 cells for various applications, the goal is to achieve 300 watt-hours per kilogram at the C/2 (5 amp) rate in a D cell configuration. The JPL role is to develop the understanding of the performance, life, and safety limiting characteristics in the cell and to transfer the technology to a manufacturer to produce a safe, high quality product in a reproducible manner. The approach taken to achieve the goals is divided into four subject areas: cathode processes and characteristics; chemical reactions and safety; cell design and assembly; and performance and abuse testing. The progress made in each of these areas is discussed

    Fast radio bursts and their gamma-ray or radio afterglows as Kerr-Newman black hole binaries

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    Fast radio bursts (FRBs) are radio transients lasting only about a few milliseconds. They seem to occur at cosmological distances. We propose that these events can be originated in the collapse of the magnetosphere of Kerr-Newman black holes (KNBHs). We show that the closed orbits of charged particles in the magnetosphere of these objects are unstable. After examining the dependencies on the specific charge of the particle and the spin and charge of the KNBH, we conclude that the resulting timescale and radiation mechanism fit well with the extant observations of FRBs. Furthermore, we argue that the merger of a KNBH binary is one of the plausible central engines for potential gamma-ray or radio afterglow following a certain FRBs, and can also account for gravitational wave (GW) events like GW 150914. Our model leads to predictions that can be tested by combined multi-wavelength electromagnetic and GW observations.Comment: 6 pages, 4 figures, accepted for publication in Ap

    Improved Memoryless RNS Forward Converter Based on the Periodicity of Residues

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    The residue number system (RNS) is suitable for DSP architectures because of its ability to perform fast carry-free arithmetic. However, this advantage is over-shadowed by the complexity involved in the conversion of numbers between binary and RNS representations. Although the reverse conversion (RNS to binary) is more complex, the forward transformation is not simple either. Most forward converters make use of look-up tables (memory). Recently, a memoryless forward converter architecture for arbitrary moduli sets was proposed by Premkumar in 2002. In this paper, we present an extension to that architecture which results in 44% less hardware for parallel conversion and achieves 43% improvement in speed for serial conversions. It makes use of the periodicity properties of residues obtained using modular exponentiation

    Molar mass and solution conformation of branched alpha(1 - 4), alpha(1 - 6) Glucans. Part I: Glycogens in water

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    Solution molar masses and conformations of glycogens from different sources (rabbit, oyster, mussel and bovine) were analysed using sedimentation velocity in the analytical ultracentrifuge, size-exclusion chromatography coupled to multi-angle laser light scattering (SEC-MALLS), size-exclusion chromatography coupled to a differential pressure viscometer and dynamic light scattering. Rabbit, oyster and mussel glycogens consisted of one population of high molar mass (weight averages ranging from 4.6 x 106 to 1.1 x 107 g/mol) as demonstrated by sedimentation velocity and SEC-MALLS, whereas bovine glycogen had a bimodal distribution of significantly lower molar mass (1.0 x 105 and 4.5 x 105 g/mol). The spherical structure of all glycogen molecules was demonstrated in the slopes of the Mark-Houwink-Kuhn-Sakurada-type power-law relations for sedimentation coefficient (s20,wo), intrinsic viscosity ([η]), radius of gyration (rg,z) and radius of hydration (rH,z), respectively, and was further supported by the � (=rg,z/rH,z) function, the fractal dimension and the Perrin function. The degree of branching was estimated to be ∼10% from the shrinking factors, g′ (=[η]branched/[η]linear) and also h (=(f/fo)branched/(f/fo)linear), respectively, where (f/fo) is the translational frictional ratio, consistent with expectation. © 2007 Elsevier Ltd. All rights reserved

    NotiMind: responses to smartphone notifications as affective sensors

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    Today's mobile phone users are faced with large numbers of notifications on social media, ranging from new followers on Twitter and emails to messages received from WhatsApp and Facebook. These digital alerts continuously disrupt activities through instant calls for attention. This paper examines closely the way everyday users interact with notifications and their impact on users’ emotion. Fifty users were recruited to download our application NotiMind and use it over a five-week period. Users’ phones collected thousands of social and system notifications along with affect data collected via self-reported PANAS tests three times a day. Results showed a noticeable correlation between positive affective measures and keyboard activities. When large numbers of Post and Remove notifications occur, a corresponding increase in negative affective measures is detected. Our predictive model has achieved a good accuracy level using three different classifiers "in the wild" (F-measure 74-78% within-subject model, 72-76% global model). Our findings show that it is possible to automatically predict when people are experiencing positive, neutral or negative affective states based on interactions with notifications. We also show how our findings open the door to a wide range of applications in relation to emotion awareness on social and mobile communication

    When challenges hinder: An investigation of buyer-imposed stressors on supplier flexibility

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    Working with buyers may drive business growth but can also induce supplier stress. Drawing on Job Demands–Resources (JD-R) theory, this study explored how buyer-imposed work stressors affect supplier flexibility. Employing a scenario-based experiment involving 338 managers, we found that the imposition of challenge stressors increases supplier flexibility when hindrance stressors are low. Conversely, when hindrance stressors are high, imposing challenge stressors reduces supplier flexibility. We also found that supplier bricolage negatively moderates the relationship between buyer-imposed challenge stressors and supplier flexibility. Specifically, we confirmed that suppliers with higher bricolage are less willing to provide flexibility in response to challenge stressors. For practitioners, our study not only identified the type of work stressors they should impose on suppliers to boost flexibility but also highlighted bricolage as an important moderating factor

    Obesity Moderates the Effects of Motivational Interviewing Treatment Outcomes in Fibromyalgia

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    Objective: Obesity is a common comorbid condition among patients with fibromyalgia (FM). Our objective was to assess if obesity moderates the treatment benefits of exercise-based motivational interviewing (MI) for FM. Methods: This is a secondary data analysis of a completed clinical trial of 198 FM patients who were randomized to receive either MI or attention control (AC). Using body mass index (BMI) to divide participants into obese (BMI >=30 kg/m2) and non-obese (BMI <30 kg m2) groups, mixed linear models were used to determine interaction between treatment arms and obesity status with regards to the primary outcome of global FM symptom severity (Fibromyalgia Impact Questionnaire, FIQ). Secondary measures included pain intensity (Brief Pain Inventory, BPI), 6-minute walk test, and self-reported physical activity (Community Health Activities Model Program for Seniors). Results: Of the 198 participants, 91 (46%) were non-obese and 107 (54%) were obese. On global FM symptom severity (FIQ), the interaction between treatment arms and obesity status was significant (P=0.02). In the non-obese group, MI was associated with a greater improvement in FIQ than AC. In the obese group, MI participants reported less improvement in FIQ compared to AC. The interaction analysis was also significant for BPI pain intensity (P=0.01), but not for the walk test and self-reported physical activity. Discussion: This is the first study to show that obesity negatively affects the treatment efficacy of MI in patients with FM. Our findings suggest that exercise-based MI may be more effective if initiated after weight loss is achieved

    Promoting participation through the universal design of built environments: making it happen

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    Environmental design is a determinant of social inclusion and people&rsquo;s participation in life roles. Design that does not cater for a diverse range of ages, abilities and cultures restricts people&rsquo;s access to, and use of, domestic or public premises. Universal design is an approach that acknowledges diversity of populations and encourages designers to create objects and places that are usable by the greatest majority of users. Although there are potential benefits to the widest application of universal design within society, such application is not mandatory within Australia. This paper presents findings from an Australian qualitative study that explored universal design as a means of facilitating greater environmental access for all. The views of experts working within the field of architecture and environmental access were explored regarding factors that restrict or facilitate application of universal design to the design of built environments. Study findings revealed a number of themes relating to factors that may restrain, &lsquo;what&rsquo;s holding us back?&rsquo; and factors that may facilitate application of universal design, &lsquo;making it happen&rsquo;. These findings have direct relevance to those involved in the planning and design of built environments, policy developers and educators

    Graphene Transport at High Carrier Densities using a Polymer Electrolyte Gate

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    We report the study of graphene devices in Hall-bar geometry, gated with a polymer electrolyte. High densities of 6 ×1013/cm2\times 10^{13}/cm^{2} are consistently reached, significantly higher than with conventional back-gating. The mobility follows an inverse dependence on density, which can be correlated to a dominant scattering from weak scatterers. Furthermore, our measurements show a Bloch-Gr\"uneisen regime until 100 K (at 6.2 ×1013/cm2\times10^{13}/cm^{2}), consistent with an increase of the density. Ubiquitous in our experiments is a small upturn in resistivity around 3 ×1013/cm2\times10^{13}/cm^{2}, whose origin is discussed. We identify two potential causes for the upturn: the renormalization of Fermi velocity and an electrochemically-enhanced scattering rate.Comment: 13 pages, 4 figures, Published Versio
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