9,602 research outputs found

    Dynamic buckling estimates

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    Dynamic buckling estimates for sensitive structures subjected to finite-time loadin

    An Exploratory Study of Forces and Frictions affecting Large-Scale Model-Driven Development

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    In this paper, we investigate model-driven engineering, reporting on an exploratory case-study conducted at a large automotive company. The study consisted of interviews with 20 engineers and managers working in different roles. We found that, in the context of a large organization, contextual forces dominate the cognitive issues of using model-driven technology. The four forces we identified that are likely independent of the particular abstractions chosen as the basis of software development are the need for diffing in software product lines, the needs for problem-specific languages and types, the need for live modeling in exploratory activities, and the need for point-to-point traceability between artifacts. We also identified triggers of accidental complexity, which we refer to as points of friction introduced by languages and tools. Examples of the friction points identified are insufficient support for model diffing, point-to-point traceability, and model changes at runtime.Comment: To appear in proceedings of MODELS 2012, LNCS Springe

    Graphene as a Novel Single Photon Counting Optical and IR Photodetector

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    Bilayer graphene has many unique optoelectronic properties , including a tuneable band gap, that make it possible to develop new and more efficient optical and nanoelectronic devices. We have developed a Monte Carlo simulation for a single photon counting photodetector incorporating bilayer graphene. Our results show that, conceptually it would be feasible to manufacture a single photon counting photodetector (with colour sensitivity) from bilayer graphene for use across both optical and infrared wavelengths. Our concept exploits the high carrier mobility and tuneable band gap associated with a bilayer graphene approach. This allows for low noise operation over a range of cryogenic temperatures, thereby reducing the cost of cryogens with a trade off between resolution and operating temperature. The results from this theoretical study now enable us to progress onto the manufacture of prototype photon counters at optical and IR wavelengths that may have the potential to be groundbreaking in some scientific research applications.Comment: Conference Proceeding in Graphene-Based Technologies, 201

    RSRM-11 (36OW011) ballistics mass properties (STS-35)

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    The propulsion performance and reconstructed mass properties data from Thiolol's RSRM-11 motors which were assigned to the STS-35 launch are contained. The Thiokol manufacturing designations for the motors were 360W011A/360W011B, which are referred to as RSRM-11A and RSRM-B, respectively. The launch of STS-35 occurred on 2 December 1990 at the Eastern Test Range (ETR). The data contained herein was input to the STS-35 Flight Evaluation Report. The SRM propellant, TP-H1148, is a composite type solid propellants, formulated of polybutediene acrylic acid, acryonitrile terpolymer binder, epoxy curing agent, ammonium perchlorate oxidizer, and aluminum powder fuel. A small amount of burning rate catalyst (iron oxide) was added to achieve the desired propellant burn rate. The propellant evaluation and raw material information for the RSRM-11 are included. The ballistic performance presented was based on the Operational Flight Instrumentation (OFI) 12.5 sample per second pressure data for the steady state and tail off portion of the pressure trace. Recent studies have shown that the transducers are affected by the measuring system at KSC and temperature gradients created by the igniter heaters. Therefore, an adjustment to the data from each transducer is made to make the initial reading match the atmospheric pressure at the time of launch

    Dissipation in nanocrystalline-diamond nanomechanical resonators

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    We have measured the dissipation and frequency of nanocrystalline-diamond nanomechanical resonators with resonant frequencies between 13.7 MHz and 157.3 MHz, over a temperature range of 1.4–274 K. Using both magnetomotive network analysis and a time-domain ring-down technique, we have found the dissipation in this material to have a temperature dependence roughly following T^(0.2), with Q^(–1) ≈ 10^(–4) at low temperatures. The frequency dependence of a large dissipation feature at ~35–55 K is consistent with thermal activation over a 0.02 eV barrier with an attempt frequency of 10 GHz

    Integrated optical directional coupler biosensor

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    We present measurements on biomolecular binding reactions, using a new type of integrated optical biosensor based on a planar directional coupler structure. The device is fabricated by Ag+-Na+ ion-exchange in glass and definition of the sensing region is achieved by use of transparent fluoropolymer isolation layers formed by thermal evaporation. The suitability of the sensor for application to the detection of environmental pollutants is considered

    Cancer patients’ experiences of living with venous thromboembolism: A systematic review and qualitative thematic synthesis

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    Background: Cancer-Associated thrombosis is common. Recommended treatment is daily injected low-molecular-weight heparin for 6months. Most studies focus on prophylaxis and treatment; few have explored patients’ experience. Aims To identify and synthesise the available literature concerning patients’ experience of cancer associated thrombosis. Design Systematic literature review and qualitative thematic synthesis. MethodsMEDLINE, Embase, CINAHL, PsychINFO (until 10/2016; limited to English) were searched. Eligible papers were qualitative studies of adult patients’ experience of cancer-associated thrombosis. Two researchers screened titles/abstracts/papers against inclusion criteria with recourse to a third for disagreements. Critical Appraisal Skills Programme qualitative checklist tool was used for quality appraisal. Results1397 articles were identified. Five qualitative studies (total n=92; age range 32 to 84 years) met the inclusion criteria. Participants had various cancer types. Most had advanced disease and were receiving palliative care. Four major themes emerged from the data: knowledge deficit (patients and clinicians); effects of cancer associated thrombosis (physical and psychological); effects of anticoagulation; coping strategies. ConclusionThe cancer journey is difficult in itself, but thrombosis was an additional, frightening and unexpected burden. Although the association between cancer and thromboembolism is well known, cancer patients are not educated routinely about the risk or warning symptoms/signs of thromboembolism which may otherwise be misattributed to the cancer by patient and clinician alike. This systematic review highlights the impact of cancer-associated thrombosis on the lives of cancer patients, and calls for education for patients and clinicians to be part of routine care, and further work to address this patient priority
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