713 research outputs found

    STR-855: INSTANTANEOUS DEFLECTIONS OF CONCRETE SLABS COMPUTED USING DISCRETIZED ANALYSIS

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    Excessive deflection of concrete floor slabs is a recurring serviceability problem (Gilbert 2012, Stivaros 2012). Current practice is to compute deflections using either a single-element idealization, where an average effective moment of inertia is assigned to the entire member, or a discretized analysis, where the member is idealized as discrete elements with unique effective moments of inertia. There are two equations available for calculating the effective moment of inertia, developed by Branson (1965) and by Bischoff (2005). Branson originally proposed two equations for effective moment of inertia, a 3rd-power equation for use in a single-element idealization and a 4th-power equation for use in a discretized-element idealization. Bischoff has proposed a single equation, based on a correct mechanical model, for use in a single-element idealization only. The research summarized in this paper investigates suitable modifications to Bischoff’s Equation for use in a discretized analysis. Simply supported members with various reinforcement ratios and live- to dead-load ratios are explored. Comparisons to experimental data are made to determine which deflection calculation procedure provides results closest to those observed

    Noncommutative partially convex rational functions

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    Motivated by classical notions of bilinear matrix inequalities (BMIs) and partial convexity, this article investigates partial convexity for noncommutative functions. It is shown that noncommutative rational functions that are partially convex admit novel butterfly-type realizations that necessitate square roots. The notion of xy-convexity, a strengthening of partial convexity arising in connection with BMIs, is also considered. A characterization of xy-convex polynomials is given

    Factor VIII: Long-established role in haemophilia A and emerging evidence beyond haemostasis

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    Abstract Factor VIII protein (FVIII) as a coagulation replacement factor has for decades been used as the standard of care for management of people with haemophilia A. It is effective for treatment of bleeding events, as prophylaxis to prevent bleeding events and preserve joint function, and to support surgery in people with haemophilia A. Despite long experience in treating haemophilia A, we are only beginning to understand the functions of FVIII beyond its established role as a coenzyme to factor IXa to expedite thrombin generation through the intrinsic pathway of coagulation. Here, we review the current role of FVIII coagulant (FVIII:C) in haemophilia A management and emerging evidence for the role of FVIII across multiple systems, including the cardiovascular system, angiogenesis and maintenance of bone health. For instance, supraphysiological FVIII levels are a risk factor for venous thromboembolism. von Willebrand factor (VWF), which forms a non-covalent complex with circulating FVIII, is an established marker and regulator of angiogenesis. In a mouse model of haemophilia, treatment with FVIII decreased expression of receptor activator of nuclear factor kappa-Î’ ligand (RANKL), a marker for bone turnover. Longitudinal follow-up data in people with haemophilia A are needed to confirm and extend these observations
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