4,419 research outputs found

    Preliminary design of an intermittent smoke flow visualization system

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    A prototype intermittent flow visualization system that was designed to study vortex flow field dynamics has been constructed and tested through its ground test phase. It produces discrete pulses of dense white smoke consisting of particles of terephthalic acid by the pulsing action of a fast-acting three-way valve. The trajectories of the smoke pulses can be tracked by a video imaging system without intruding in the flow around in flight. Two methods of pulsing the smoke were examined. The simplest and safest approach is to simply divert the smoke between the two outlet ports on the valve; this approach should be particularly effective if it were desired to inject smoke at two locations during the same test event. The second approach involves closing off one of the outlet ports to momentarily block the flow. The second approach requires careful control of valve dwell times to avoid excessive pressure buildup within the cartridge container. This method also increases the velocity of the smoke injected into the flow. The flow of the smoke has been blocked for periods ranging from 30 to 80 milliseconds, depending on the system volume and the length of time the valve is allowed to remain open between valve closings

    Potential Impact of Gramm-Rudman on the American Family: Critical Research Questions for Social Work

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    The University Archives has determined that this item is of continuing value to OSU's history.Keynote Speaker 2: James H. Ward, Ph.D., Dean, University of Alabama School of Social Work - "Potential Impact of Gramm-Rudman on the American Family".The Ohio State University College of Social Wor

    Empirical Support for the PCAOB’s Elimination of the Independent Auditor’s Opinion Regarding Management’s Assessment of Internal Control

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    In an attempt to bolster public confidence in the accounting profession, the PCAOB issued several standards that were intended to address weaknesses in audit reporting and to increase public confidence in financial reporting. One of these standards, Auditing Standard No.2, added two opinions on an enterprise’s internal control to audit reporting requirements. This Standard was superseded by Auditing Standard No. 5, which eliminated one of these opinions. The purpose of this paper is to examine the efficacy of the elimination of the auditor’s opinion regarding management’s assessment of internal control. The data in this study were taken from 10-K reports filed by Fortune 500 Companies in 2004-2007. From the 10-K reports, copies of audit reports were gathered for 114 of the 120 largest companies and the opinions (unqualified, qualified, or adverse) were recorded

    Issues with management, maintenance and upkeep in ETFE enclosures

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    Ethylene tetra-fluoro-ethylene (ETFE) foil, as a single layer or as multi-layer inflated cushions, has been in used in the building industry for nearly 30 years as a medium to cover and clad both façades and atria. Its longevity has been well publicised and proven with many projects showing little or no signs of degradation. The number of ETFE foil structures has been steadily rising in recent years, and with this the inevitable need for maintenance has also risen. The anticipated life of ETFE foil is now suggested to be as long as 50 years [1], and as with any other building material, regular inspections are necessary to ensure the continued optimal operation of the enclosure

    Groundwater faunas as indicators of groundwater quality: the South Platte River system

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    February 1989.Bibliography: pages 33-39

    MtsslWizard: In Silico Spin-Labeling and Generation of Distance Distributions in PyMOL

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    MtsslWizard is a computer program, which operates as a plugin for the PyMOL molecular graphics system. MtsslWizard estimates distances between spin labels on proteins quickly with user-configurable options through a simple graphical interface. In default mode, the program searches for ensembles of possible MTSSL conformations that do not clash with a static model of the protein. Once conformations are assigned, distance distributions between two or more ensembles are calculated, displayed, and can be exported to other software. The program’s use is evaluated in a number of challenging test cases and its strengths and weaknesses evaluated. The benefits of the program are its accuracy and simplicity

    Light Reading: Optimizing Reader/Writer Locking for Read-Dominant Real-Time Workloads (Artifact)

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    This paper is directed at reader/writer locking for read-dominant real-time workloads. It is shown that state-of-the-art real-time reader/writer locking protocols are subject to performance limitations when reads dominate, and that existing schedulability analysis fails to leverage the sparsity of writes in this case. A new reader/writer locking-protocol implementation and new inflation-free schedulability analysis are proposed to address these problems. Overhead evaluations of the new implementation show a decrease in overheads of up to 70% over previous implementations, leading to throughput for read operations increasing by up to 450%. Schedulability experiments are presented that show that the analysis results in schedulability improvements of up to 156.8% compared to the existing state-of-the-art approach
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