146 research outputs found

    Apollo water impact Status report, 1 Apr. - 1 Oct. 1969

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    Hydrodynamic impact simulated by impacting rigid, right circular cylinder on smooth water surface, and computer progra

    Apollo water impact Status report, 1 Oct. 1969 - 1 Mar. 1970

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    Computer program for Apollo water landin

    Hydrodynamic water impact

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    The hydrodynamic impact of a falling body upon a viscous incompressible fluid was investigated by numerically solving the equations of motion. Initially the mathematical model simulated the axisymmetric impact of a rigid right circular cylinder upon the initially quiescent free surface of a fluid. A compressible air layer exists between the falling cylinder and the liquid free surface. The mathematical model was developed by applying the Navier-Stokes equations to the incompressible air layer and the incompressible fluid. Assuming the flow to be one dimensional within the air layer, the average velocity, pressure and density distributions were calculated. The liquid free surface was allowed to deform as the air pressure acting on it increases. For the liquid the normalized equations were expressed in two-dimensional cylindrical coordinates. The governing equations for the air layer and the liquid were expressed in finite difference form and solved numerically. For the liquid a modified version of the Marker-and-Cell method was used. The mathematical model has been reexamined and a new approach has recently been initiated. Essentially this consists of examining the impact of an inclined plate onto a quiesent water surface with the equations now formulated in cartesian coordinates

    Improvement of propeller static thrust estimation Status report, 1 Nov. 1968 - 31 Aug. 1969

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    Aerodynamic load effects on propeller blade desig

    Improvement of propeller static thrust estimation

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    The problem of improving the performance estimation of propellers operating in the heavily loaded static thrust condition was studied. The Goldstein theory was assessed as it applies to propellers operating in the static thrust. A review of theoretical considerations is presented along with a summary of the attempts made to obtain a numerical solution. The chordwise pressure distribution was determined during operation at a tip speed of 500 ft/sec. Chordwise integration of the pressures leads to the spanwise load distribution and further integration would give the axial thrust

    Tests on propellers under static thrust conditions

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    Dynamometer tests of propellers under static thrust condition

    Desiccant Cooling Systems - A Review

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    Desiccant cooling systems have been investigated extensively during the past decade as alternatives to electrically driven vapor compression systems because regeneration temperatures of the desiccant - about 160°F, can be achieved using natural gas or by solar systems. Comfort is achieved by reducing the moisture content of air by a solid or liquid desiccant and then reducing the temperature in an evaporative cooler (direct or indirect). Another system is one where the dehumidifier removes enough moisture to meet the latent portion of the load while the sensible portion is met by a vapor compression cooling system; desiccant regeneration is achieved by using the heat rejected from the condenser together with other thermal sources. At present, residential desiccant cooling systems are in actual operation but are more costly than vapor compression systems, resulting in relatively long payback periods. Component efficiencies need to be improved, particularly the efficiency of the dehumidifier

    Desiccant Cooling Systems - A Review

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    Desiccant cooling systems have been investigated extensively during the past decade as alternatives to electrically driven vapor compression systems because regeneration temperatures of the desiccant - about 160°F, can be achieved using natural gas or by solar systems. Comfort is achieved by reducing the moisture content of air by a solid or liquid desiccant and then reducing the temperature in an evaporative cooler (direct or indirect). Another system is one where the dehumidifier removes enough moisture to meet the latent portion of the load while the sensible portion is met by a vapor compression cooling system; desiccant regeneration is achieved by using the heat rejected from the condenser together with other thermal sources. At present, residential desiccant cooling systems are in actual operation but are more costly than vapor compression systems, resulting in relatively long payback periods. Component efficiencies need to be improved, particularly the efficiency of the dehumidifier

    Structure of a potential therapeutic antibody bound to Interleukin-16 (IL-16): mechanistic insights and new therapeutic opportunities

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    Interleukin-16 (IL-16) is reported to be a chemoattractant cytokine and modulator of T-cell activation, and has been proposed as a ligand for the co-receptor CD4. The secreted active form of IL-16 has been detected at sites of TH1-mediated inflammation, such as those seen in autoimmune diseases, ischemic reperfusion injury (IRI), and tissue transplant rejection. Neutralization of IL-16 recruitment to its receptor, using an anti-IL16 antibody, has been shown to significantly attenuate inflammation and disease pathology in IRI, as well as in some autoimmune diseases. The 14.1 antibody is a monoclonal anti-IL-16 antibody, which when incubated with CD4+ cells is reported to cause a reduction in the TH1-type inflammatory response. Secreted IL-16 contains a characteristic PDZ domain. PDZ domains are typically characterized by a defined globular structure, along with a peptide-binding site located in a groove between the αB and βB structural elements and a highly conserved carboxylate-binding loop. In contrast to other reported PDZ domains, the solution structure previously reported for IL-16 reveals a tryptophan residue obscuring the recognition groove. We have solved the structure of the 14.1Fab fragment in complex with IL-16, revealing that binding of the antibody requires a conformational change in the IL-16 PDZ domain. This involves the rotation of the αB-helix, accompanied movement of the peptide groove obscuring tryptophan residue, and consequent opening up of the binding site for interaction. Our study reveals a surprising mechanism of action for the antibody and identifies new opportunities for the development of IL-16-targeted therapeutics, including small molecules that mimic the interaction of the antibody

    Sustainability Education Beyond the Classroom: How the “Exploding University” Nurtures Collective Intelligence Across Local and Global Communities

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    This chapter explores how the authors expanded their teaching and learning beyond the classroom at Manchester Metropolitan University in the UK. It puts forward the theoretical concept of the “exploding university” as a way to help develop a critical yet hopeful understanding of collective problems at local and global scales. This helps them explore three interrelated initiatives that brought teachers, students, and communities together, namely a sustainability festival, research project on animal rehoming, and community tree-planting drive. The chapter illuminates how exploding the work beyond the classroom enabled everyone involved to take action on the challenges that matter to them, while also developing a “collective intelligence” about their underlying causes. The exploding university thus emerges as a theoretical and practical model, which we can use to inspire students to actively critique, reimagine, and reconstruct the world around them. The authors conclude by encouraging and supporting others who might wish to embark on similar journeys themselves
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