226 research outputs found

    View factor computer program (VIEW)

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    Existing view factor program, RAVFAC, was modified to accept NASTRAN and/or RAVFAC surface descriptions. Output formatting was altered to produce view factor matrices which could be directly input to NASTRAN

    Three-axis controller Patent

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    Three-axis controller operated by hand-wrist motion for yaw, pitch, and roll contro

    Interpolating for the location of remote sensor data

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    An interpolation algorithm is presented as a practical alternative to common interpolation and approximation methods when applied to the problem of determining the location of remote sensor data. This algorithm is based upon knowledge of the geometry of the problem and is shown to be inherently more accurate than common interpolation schemes which may be applied to all types of data. A practical location problem is used to demonstrate its accuracy and computational cost

    TOMS Near Realtime System design document

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    The System Design Document for the TOMS (Total Mapping Spectrometer) Near Realtime System provides detailed definition of the system functions and records the system history from a data processing and development point-of-view. The system was designed to produce map products displaying ozone concentrations over the United States as measured by the TOMS flown on the NIMBUS 7 satellite. The maps were produced and delivered to the user within six hours of round receipt of the satellite data for the period March 1, 1981 through May 15, 1981 on a daily basis. Sample system products are shown and data archival locations are listed

    View factor computer program (program view) user's manual

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    The purpose of program VIEW is to compute view factors between specified surfaces and to be compatible with level 15.5 of the NASTRAN structural analysis program. Program VIEW is a modification of a (finite element) view factor computation program called RAVFAC. VIEW is designed to run on an IBM System/360 operating under OS (operating system), with a minimum region size of 110 K bytes. The actual computation of view factors is still performed exactly as it was in the original version of RAVFAC. In developing VIEW, RAVFAC was modified to satisfy the following compatibility requirements: (1) accept finite element input which can also be used as input to NASTRAN, (2) produce output (view factors) in a format which can be used as input to NASTRAN, and (3) follow NASTRAN program design so that in the future VIEW can be incorporated into NASTRAN as a subroutine. The VIEW program permits computation of the view factors between surfaces, taking into account the presence of any intermediate surfaces. VIEW also computes these view factors either by contour integration or by finite difference (double summation) methods

    Ecological feedback mechanisms and variable disturbance regimes: the uncertain future of Mediterranean macroalgal forests

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    Loss of algal canopies can result in a shift towards a turf-dominated state, where variability in species life-history traits can determine new mechanisms of feedback, and influence the degraded system under variable regimes of disturbance. By focusing on rockpools dominated by Cystoseira brachycarpa, we tested the hypothesis that the alga Dictyopteris polypodioides could take advantage of extreme regimes of disturbance related to storms, and outcompete other turfs through a distinctive combination of life traits. Replacement of the canopy was initially driven by a mix of taxon-specific life-traits and resulting assemblages were susceptible to intense events of disturbance. Subsequently, D. polypodioides dominated removal quadrats, favored by density-dependent abilities to intercept more light and reach larger size than the rest of turf. These new positive feedbacks may contribute to maintain the modified state of the system and influence its ability to withstand extreme abiotic conditions

    Rapid Solvent-Free Microcrystalline Cellulose Melt Functionalization with L-Lactide for the Fabrication of Green Poly-Lactic Acid Biocomposites

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    A green approach is proposed to achieve a rapid surface functionalization of microcrystalline cellulose (MCC) in 30 min by a solvent-free grafting by the reaction of L-lactide through compression molding without the need for an inert atmosphere. A sufficient hydrophobization of the MCC surface is achieved with an amount of grafted poly(L-lactic acid) (PLLA) oligomers of 7 wt % with respect to MCC. The obtained PLLA-g-MCC is subsequently melt-compounded with poly(lactic acid) (PLA) through extrusion and injection molding. As a result of higher compatibility and interfacial adhesion of the functionalized filler with PLA, PLA/ MCC-g-PLLA biocomposites with a cellulose content ranging from 4 to 20 wt % exhibit an enhancement in important physicochemical properties (i.e., water vapor barrier, crystallinity, stiffness) compared to both pure PLA and formulations containing an equal or higher amount of nonfunctionalized MCC. At the same time, the materials retain the mechanical strength and resistance to thermal degradation of PLA. The physicochemical characteristics, excellent biocompatibility, and biodegradability of PLA and cellulose and the simplicity, rapidity, and cost-effectiveness of the grafting process render these biocomposites suitable for several applications within the plastics domain including packaging, agriculture, automotive, consumer goods, and household appliances

    Multi-criteria approach for the environmental impact assessment of inland aquaculture

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    Trout farming, that represents the most important sector for aquaculture inland production in Italy, can cause negative effects on aquatic ecosystems. Recently, in the framework of Water Frame Directive 2000/60/EC and national law DL 152/2006, concerning the sustainable uses of water resources, multi-criteria approaches have been suggested to evaluate the impact of fish farming on aquatic ecosystems. In this study trout farms of central Italy were selected to investigate the effects of their effluents, on receiving water bodies using a multi-criteria approach based on physicochemical parameters, microbiological and macrobenthonic indicators, detected in sampling stations located upstream/downstream the trout farm. Moreover, antibiotic susceptibility against antibiotics allowed and/or forbidden by current law (D.lgs 193/56/06) was tested on E. coli strains. The results indicate variations of chemical parameters and biological indicators from upstream to downstream sites in some of the investigated farms. Antibiotic resistance of E. coli strains suggested a large use of tetracycline and a possible past use of chloramphenicol. This study represents a first contribute to the knowledge of fish farm impacts on aquatic systems in Central Italy

    Procedural Complications During Early Versus Late Endovascular Treatment in Acute Stroke: Frequency and Clinical Impact

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    BACKGROUND AND PURPOSE: Endovascular treatment (EVT) in acute ischemic stroke is effective in the late time window in selected patients. However, the frequency and clinical impact of procedural complications in the early versus late time window has received little attention. METHODS: We retrospectively studied all acute ischemic strokes from 2015 to 2019 receiving EVT in the Acute Stroke Registry and Analysis of Lausanne. We compared the procedural EVT complications in the early (<6 hours) versus late (6-24 hours) window and correlated them with short-term clinical outcome. RESULTS: Among 695 acute ischemic strokes receiving EVT (of which 202 were in the late window), 113 (16.3%) had at least one procedural complication. The frequency of each single, and for overall procedural complications was similar for early versus late EVT (16.2% versus 16.3%, Padj=0.90). Procedural complications lead to a significantly less favorable short-term outcome, reflected by the absence of National Institutes of Health Stroke Scale improvement in late EVT (delta-National Institutes of Health Stroke Scale-24 hours, -2.5 versus 2, Padj=0.01). CONCLUSIONS: In this retrospective analysis of consecutive EVT, the frequency of procedural complications was similar for early and late EVT patients but very short-term outcome seemed less favorable in late EVT patients with complications

    Hybrid conferences: opportunities, challenges and ways forward

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    Hybrid conferences are in-person events that have an online component. This type of meeting format was rare before the COVID-19 pandemic, but started to become more common recently given the asynchronous global progression of the pandemic, the uneven access to vaccines and different travel regulations among countries that led to a large proportion of participants being unable to attend conferences in person. Here we report the organization of a middle-sized (581 participants: 159 onsite, 422 online) international hybrid conference that took place in France in September 2021. We highlight particular organizational challenges inherent to this relatively new type of meeting format. Furthermore, we surveyed both in-person and online participants to better understand their conference experience and to propose improvements based on the feedback received. Finally, we compare the advantages and disadvantages of three types of conferences (onsite-only, online-only and hybrid) and suggest that hybrid events should be favored in the future because they offer the most flexibility to participants. We conclude by proposing suggestions and ways forward to maximize accessibility and inclusivity of hybrid conferences. Our study brings novel insights on the challenges and opportunities created by hybrid conferences, by reporting not only the organizing committee experience but also by considering the participants’ perspective
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