40,856 research outputs found
Nondestructive testing for braze voids in thin panels by use of special coatings
Application of commercial coating to exterior of sandwich panel structures for determining presence of voids in brazed plates is discussed. Procedure for applying coating material and method of conducting nondestructive tests are explained. Illustrations are included to show appearance of voids
Turbulence and turbulent mixing in natural fluids
Turbulence and turbulent mixing in natural fluids begins with big bang
turbulence powered by spinning combustible combinations of Planck particles and
Planck antiparticles. Particle prograde accretions on a spinning pair releases
42% of the particle rest mass energy to produce more fuel for turbulent
combustion. Negative viscous stresses and negative turbulence stresses work
against gravity, extracting mass-energy and space-time from the vacuum.
Turbulence mixes cooling temperatures until strong-force viscous stresses
freeze out turbulent mixing patterns as the first fossil turbulence. Cosmic
microwave background temperature anisotropies show big bang turbulence fossils
along with fossils of weak plasma turbulence triggered as plasma photon-viscous
forces permit gravitational fragmentation on supercluster to galaxy mass
scales. Turbulent morphologies and viscous-turbulent lengths appear as linear
gas-proto-galaxy-clusters in the Hubble ultra-deep-field at z~7. Proto-galaxies
fragment into Jeans-mass-clumps of primordial-gas-planets at decoupling: the
dark matter of galaxies. Shortly after the plasma to gas transition,
planet-mergers produce stars that explode on overfeeding to fertilize and
distribute the first life.Comment: 23 pages 12 figures, Turbulent Mixing and Beyond 2009 International
Center for Theoretical Physics conference, Trieste, Italy. Revision according
to Referee comments. Accepted for Physica Scripta Topical Issue to be
published in 201
Higher-order compatible finite element schemes for the nonlinear rotating shallow water equations on the sphere
We describe a compatible finite element discretisation for the shallow water
equations on the rotating sphere, concentrating on integrating consistent
upwind stabilisation into the framework. Although the prognostic variables are
velocity and layer depth, the discretisation has a diagnostic potential
vorticity that satisfies a stable upwinded advection equation through a
Taylor-Galerkin scheme; this provides a mechanism for dissipating enstrophy at
the gridscale whilst retaining optimal order consistency. We also use upwind
discontinuous Galerkin schemes for the transport of layer depth. These
transport schemes are incorporated into a semi-implicit formulation that is
facilitated by a hybridisation method for solving the resulting mixed Helmholtz
equation. We illustrate our discretisation with some standard rotating sphere
test problems.Comment: accepted versio
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How Useful are High-Precision Delta ?17O Data in Defining the Asteroidal Sources of Meteorites?: Evidence from Main-Group Pallasites, Primitive and Differentiated Achondrites
High-precision oxygen isotope analysis is capable of revealing important information about the relationship between different meteorite groups. New data confirm that the main-group pallasites are from a distinct source to either the HEDs or mesosiderites
Pressure containment tests in support of the nuclear Brayton cycle heat exchanger and duct assembly /HXDA/, phase 2
Plate-fin heat exchangers for nuclear reactor Brayton cycl
Brayton heat exchanger unit development program (alternate design)
A Brayton Heat Exchanger Unit Alternate Design (BHXU-Alternate) consisting of a recuperator, a heat sink heat exchanger, and a gas ducting system, was designed and fabricated. The design was formulated to provide a high performance unit suitable for use in a long-life Brayton-cycle powerplant. Emphasis was on double containment against external leakage and leakage of the organic coolant into the gas stream. A parametric analysis and design study was performed to establish the optimum component configurations to achieve low weight and size and high reliability, while meeting the requirements of high effectiveness and low pressure drop. Layout studies and detailed mechanical and structural design were performed to obtain a flight-type packaging arrangement, including the close-coupled integration of the BHXU-Alternate with the Brayton Rotating Unit (BRU)
Fraternal New Member Processes: An Alumni Perspective
Hazing has always been an issue in fraternities and sororities. Even though there has been a push to reduce the amount of hazing through research and trainings, it continues to cause harm to the community. The purpose of this study is to gain incite from fraternity alums toward understanding the use of hazing activities while orienting fraternity men to the organization. This study examined the issue from the individuals experience, to their role in inducting new members, and now as alums to gain insight in to why chapters continue to that cycle. Results showed that individuals in groups social construct their definition of hazing and these new member processes need to continue to evolve to better shift the culture of the chapters
Gravitational hydrodynamics of large scale structure formation
The gravitational hydrodynamics of the primordial plasma with neutrino hot
dark matter is considered as a challenge to the bottom-up cold dark matter
paradigm. Viscosity and turbulence induce a top-down fragmentation scenario
before and at decoupling. The first step is the creation of voids in the
plasma, which expand to 37 Mpc on the average now. The remaining matter clumps
turn into galaxy clusters. Turbulence produced at expanding void boundaries
causes a linear morphology of 3 kpc fragmenting protogalaxies along vortex
lines. At decoupling galaxies and proto-globular star clusters arise; the
latter constitute the galactic dark matter halos and consist themselves of
earth-mass H-He planets. Frozen planets are observed in microlensing and
white-dwarf-heated ones in planetary nebulae. The approach also explains the
Tully-Fisher and Faber-Jackson relations, and cosmic microwave temperature
fluctuations of micro-Kelvins.Comment: 6 pages, no figure
Are Antidepressants Overprescribed? Patients’ Experiences of the Prescribing Process
An online survey was completed by 1829 New Zealand adults prescribed antidepressants. Only 43% were experiencing self-reported “severe” depression when first prescribed antidepressants. Thus, most prescriptions were for depression that was self-reported as mild or moderate, despite studies suggesting that antidepressants are no more effective than placebo at these levels. General practitioners (GPs) prescribed at lower depression levels than psychiatrists and spent less time with patients. 35% of GPs and 42% of psychiatrists reportedly gave no information about adverse effects. Almost no prescribers gave information about adverse effects in the personal and interpersonal domains, or about withdrawal effects. Closer adherence to evidence-based prescribing and to the principle of informed consent may lead to a reduction in unnecessary, ineffective, and potentially harmful prescribing
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