2,718 research outputs found

    Finite Element Programme Development for the Analysis of Precast Flooring and Roofing System

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    At the initial stage of this study an attempt was made to write a computer programme for the analysis and design of precast floor slabs on the FORTRAN language, which is compatible with FORTRAN 90 Power Station. The programme considers various types of precast reinforced concrete slabs such as solid slab (one-way and two-way), hollow core slab, ribbed slab and composite slab. The programme consists of a main and several subroutines. The programme was written according to BS 8110 and was verified by using it to analyse a few examples. The software is capable of analysing and designing different floor slabs with a provision for generating the optimal crosssection and plotting the cross section graphically. Further, the effect of different design parameters on the solid slab, hollow slab and ribbed slab design had been presented. One of the main objectives of this study was the development of a finite element code using the semi-loof beam and shell elements. The application of these elements to model the precast flooring and roofing system was illustrated. The validity of the developed programme was established by analysing some benchmark problems and comparing the results with those from a commercial package. The results indicate that the use of the semi-loof elements resulted in a powerful programme, which is suitable for the analysis of complex shell type structures. Another primary objective of this investigation was the analysis of a composite slab, which consisted of precast and insitu layers. There was a need to model two different materials along with their interface characteristic. An interface element sandwiched between two 16-noded isoparametric brick element has been formulated. This interface element was used in an existing three dimensional finite element package. The behaviour of the composite slab under load with respect to displacements, stresses and strains was studied. It was found that it was important to model frictional behaviour between the two different materials as in composite slabs

    Narrating regions: New Storytelling technique helps increasing people's analysis and information sharing

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    Sound information at sub-national level and benchmarking of regions across national borders has increased in importance in the policy agenda of many countries due to higher integration driven by institutional processes and economic globalisation. Geovisual analytics techniques help illustrating complex data such as regional, spatiotemporal and multidimensional statistics. Interactive time-linked visual representations enable the users to simultaneously analyse relations among different variables. "OECD eXplorer", developed by NCVA in collaboration with OECD, is today a worldwide recognized web-enabled tool for visualizing and better understanding the socio-economic structure of OECD regions and their performance over time. Geovisual Analytics in the OECD explorer has so far focused more on tools to analyse regional economic performance than on methods that efficiently publish gained knowledge. Publication is indeed part of the analytical process and it could become a catalyst for discussion generating new value in a social setting. In this context, we introduce a novel storytelling that supports the editorial authoring process with the goal to advance technology critical to the sharing of information and publishing. With the introduction of this new technique, we are moving away from a clear distinction between authors and readers: The analyst can discuss with interested readers the visual discoveries which have been captured into snapshots together with descriptive text and hyperlinks. The author gets feedback from colleagues, adapts the story and publishes it using a "Vislet" that is embedded in blogs or wikis. This advanced storytelling technology applied to OECD eXplorer can therefore become a complete on-line publication to highlight recent trends and relevant disparities among OECD regions

    High speed InAs electron avalanche photodiodes overcome the conventional gain-bandwidth product limit

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    High bandwidth, uncooled, Indium Arsenide (InAs) electron avalanche photodiodes (e-APDs) with unique and highly desirable characteristics are reported. The e-APDs exhibit a 3dB bandwidth of 3.5 GHz which, unlike that of conventional APDs, is shown not to reduce with increasing avalanche gain. Hence these InAs e-APDs demonstrate a characteristic of theoretically ideal electron only APDs, the absence of a gain-bandwidth product limit. This is important because gain-bandwidth products restrict the maximum exploitable gain in all conventional high bandwidth APDs. Non-limiting gain-bandwidth products up to 580 GHz have been measured on these first high bandwidth e-APDs. (C) 2011 Optical Society of Americ

    A Data-driven Approach Towards Human-robot Collaborative Problem Solving in a Shared Space

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    We are developing a system for human-robot communication that enables people to communicate with robots in a natural way and is focused on solving problems in a shared space. Our strategy for developing this system is fundamentally data-driven: we use data from multiple input sources and train key components with various machine learning techniques. We developed a web application that is collecting data on how two humans communicate to accomplish a task, as well as a mobile laboratory that is instrumented to collect data on how two humans communicate to accomplish a task in a physically shared space. The data from these systems will be used to train and fine-tune the second stage of our system, in which the robot will be simulated through software. A physical robot will be used in the final stage of our project. We describe these instruments, a test-suite and performance metrics designed to evaluate and automate the data gathering process as well as evaluate an initial data set.Comment: 2017 AAAI Fall Symposium on Natural Communication for Human-Robot Collaboratio

    A serious adverse surgical event: Management of suspected HSV-1 keratitis in a donor cornea.

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    PurposeTo describe the management of a serious adverse event in a patient undergoing penetrating keratoplasty (PK).Case reportA 68-year-old man underwent PK for an aphakic bullous keratopathy following previous complicated cataract surgery. He had no past history of herpetic disease. Storage of the corneoscleral disc in the transport bottle precluded microscopic examination. After placement of the trephined donor cornea on the open eye of the recipient, a large dendritiform geographic ulcer was noted on the donor cornea. A replacement cornea was used after changing potentially contaminated instruments. Intravenous antiviral treatment was commenced intraoperatively to reduce the risk of infection to the central nervous system. Postoperatively, oral and topical antiviral treatment was commenced and 6 months following surgery the patient developed a geographic corneal ulcer at the graft host interface.ConclusionContainers to transport corneoscleral discs should enable microscopic examination by the surgeon prior to use. High dose systemic antivirals may reduce the risk of herpetic disease involving the posterior segment of the eye and neuroretina in the aphakic eye and spread to the central nervous system

    People learn other people's preferences through inverse decision-making

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    People are capable of learning other people's preferences by observing the choices they make. We propose that this learning relies on inverse decision-making -- inverting a decision-making model to infer the preferences that led to an observed choice. In Experiment 1, participants observed 47 choices made by others and ranked them by how strongly each choice suggested that the decision maker had a preference for a specific item. An inverse decision-making model generated predictions that were in accordance with participants' inferences. Experiment 2 replicated and extended a previous study by Newtson (1974) in which participants observed pairs of choices and made judgments about which choice provided stronger evidence for a preference. Inverse decision-making again predicted the results, including a result that previous accounts could not explain. Experiment 3 used the same method as Experiment 2 and found that participants did not expect decision makers to be perfect utility-maximizers

    A High Efficiency Aluminum-Ion Battery Using an AlCl3-Urea Ionic Liquid Analogue Electrolyte

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    In recent years, impressive advances in harvesting renewable energy have led to pressing demand for the complimentary energy storage technology. Here, a high coulombic efficiency (~ 99.7%) Al battery is developed using earth-abundant aluminum as the anode, graphite as the cathode, and a cheap ionic liquid analogue electrolyte made from a mixture of AlCl3 and urea in 1.3 : 1 molar ratio. The battery displays discharge voltage plateaus around 1.9 V and 1.5 V (average discharge = 1.73 V) and yielded a specific cathode capacity of ~73 mAh g-1 at a current density of 100 mA g-1 (~ 1.4 C). High coulombic efficiency over a range of charge-discharge rates and stability over ~150-200 cycles was easily demonstrated. In-situ Raman spectroscopy clearly showed chloroaluminate anion intercalation/deintercalation of graphite in the cathode side during charge/discharge and suggested the formation of a stage 2 graphite intercalation compound when fully charged. Raman spectroscopy and nuclear magnetic resonance suggested the existence of AlCl4-, Al2Cl7- anions, and [AlCl2. (urea)n]+ cations in the urea/AlCl3 electrolyte when an excess of AlCl3 was present. Aluminum deposition therefore proceeded through two pathways, one involving Al2Cl7- anions and the other involving [AlCl2.(urea)n]+ cations. This battery is a promising prospect for a future high performance, low cost energy storage device

    Profibrinolytic effect of the epigenetic modifier valproic acid in man.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.The aim of the study was to test if pharmacological intervention by valproic acid (VPA) treatment can modulate the fibrinolytic system in man, by means of increased acute release capacity of tissue plasminogen activator (t-PA) as well as an altered t-PA/Plasminogen activator inhibitor -1 (PAI-1) balance. Recent data from in vitro research demonstrate that the fibrinolytic system is epigenetically regulated mainly by histone deacetylase (HDAC) inhibitors. HDAC inhibitors, including VPA markedly upregulate t-PA gene expression in vitro.The trial had a cross-over design where healthy men (n = 10), were treated with VPA (Ergenyl Retard) 500 mg depot tablets twice daily for 2 weeks. Capacity for stimulated t-PA release was assessed in the perfused-forearm model using intra-brachial Substance P infusion and venous occlusion plethysmography. Each subject was investigated twice, untreated and after VPA treatment, with 5 weeks wash-out in-between. VPA treatment resulted in considerably decreased levels of circulating PAI-1 antigen from 22.2 (4.6) to 10.8 (2.1) ng/ml (p<0.05). It slightly decreased the levels of circulating venous t-PA antigen (p<0.05), and the t-PA:PAI-1 antigen ratio increased (p<0.01). Substance P infusion resulted in an increase in forearm blood flow (FBF) on both occasions (p<0.0001 for both). The acute t-PA release in response to Substance P was not affected by VPA (p = ns).Valproic acid treatment lowers plasma PAI-1 antigen levels and changes the fibrinolytic balance measured as t-PA/PAI-1 ratio in a profibrinolytic direction. This may in part explain the reduction in incidence of myocardial infarctions by VPA treatment observed in recent pharmacoepidemiological studies.The EU Clinical Trials Register 2009-011723-31.Swedish Heart-Lung Foundation Swedish Research Council Emelle Foundatio
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