2,726 research outputs found
Energy transfer in a beam-framed structure using a modal method and a wave method at mid frequencies
A fully framed system consisting of four beams and a rectangular plate has been investigated in terms of the energy transfer between the beams and the plate when a force is applied to one of the beams. This configuration, which is a mixture of stiff and flexible elements, is a particularly important example in the industrial area, as it is widely used. A modal model based on interface basis functions is used. A wave model, which is an approximate method, has also been developed in which the plate, acting as a wave impedance, is separately attached to each beam. Experimental studies have been carried out for validation. The investigation with respect to power flow and energy shows the validity of both models in the mid-frequency region. The results show that most energy is dissipated by the flexible plate. The physical phenomena and limitations of the wave method for this particular structural configuration are discussed. Even though it is an approximate method, the wave approach can describe the dynamic characteristics of the excited beam and the plate in terms of the ratios of power and energy of each component. The comparison of the two methods shows that the plate rather than the beams plays a crucial role in transferring the energy from the excited beam to the parallel opposite beam in the beam-framed structure when these two beams have identical properties, whereas the energy transfer is reduced when the beams have dissimilar properties
Corn Silage for Beef Production
The object of this experiment was to ascertain the feeding value of silage made from corn cut at different stages of growth. In other feeding trials made at this Station it has been shown that corn silage when fed alone without other supplementary feeds produces very satisfactory gains and at a comparatively low cost. Sometimes corn does not mature or is frosted before being put into the silo. These feeding trials were conducted to determine the feed value of corn silage for steers when made under the following conditions: 1. When in the blister or milk stage. 2. When in the dough stage. 3. When in the glazed or dented stage. 4. When well matured but frosted
The Sheep
The sheep is one of the most profitable animals on the farm. Besides increasing the fertility of the land sheep furnish two incomes during the year, namely; from the sale of wool in the summer and from the sale of lambs in ·the fall or winter. Sheep are economical meat producers, requiring less than the average number of pounds of feed to produce a pound of gain. This gain usually brings as much in the market as gain made by any other meat-producing animal. The gain is oftentimes made under conditions where other animals would starve, and also from vegetation in fields which would probably otherwise be a waste. Sheep have no equal as a weed destroyer, eating nearly all the weeds and grasses found on the farm. I have seen sheep in the dry lot eat Canadian thistles given with green feed. By eating these ,weeds and weed seeds sheep aid in getting the farm into a better state of cultivation. Sheep need pasture up :to the time grain is stacked, but from then on they will live and do well in the stubble field where rape has been sown with the small grain, until after corn is husked, then they do well in the stalk field.· The lambs at weaning time can be turned into the cornfield and they will eat the corn leaves and husks, do well, and get in condition for the butcher before they learn to eat corn from the ear. The object of this bulletin is to furnish information on the care of sheep for the production of mutton and wool. For convenience, we have treated the two subjects separately. Since the editions of nearly all our bulletins at this Station on feeding sheep are exhausted, we also include herein some of the results o.f our former experiments
Treatment of hypertension following endotracheal intubation A study comparing the efficacy of labetalol, practolol and placebo
Labetalol, a new adrenergic receptor antagonist, has both a- and B-blocking properties. Intravenous labetalol (0,25 and 0,5 mg/kg), practolol (0,4 mg/kg) and saline (1 ml), injected prior to anaesthesia, were compared with respect to their effect on the haemodynamic consequences of direct laryngoscopy followed by the passage of an endotracheal tube. When compared with intravenous saline injection, both labetalol and practolol obtunded the tachycardia induced by endotracheal intubation. The higher dose of labetalol was more effective in reducing the hypertensive response than the lower dose of practolol. However, none of the regimens completely abolished the adverse haemodynamic consequences of laryngotracheal, manipulations
Effect of La doping on magnetic structure in heavy fermion CeRhIn5
The magnetic structure of Ce0.9La0.1RhIn5 is measured using neutron
diffraction. It is identical to the incommensurate transverse spiral for
CeRhIn5, with a magnetic wave vector q_M=(1/2,1/2,0.297), a staggered moment of
0.38(2)Bohr magneton per Ce at 1.4K and a reduced Neel temperature of 2.7 K.Comment: 5 pages, 2 figures, 1 table. Conf. SCES'200
Molecular scale contact line hydrodynamics of immiscible flows
From extensive molecular dynamics simulations on immiscible two-phase flows,
we find the relative slipping between the fluids and the solid wall everywhere
to follow the generalized Navier boundary condition, in which the amount of
slipping is proportional to the sum of tangential viscous stress and the
uncompensated Young stress. The latter arises from the deviation of the
fluid-fluid interface from its static configuration. We give a continuum
formulation of the immiscible flow hydrodynamics, comprising the generalized
Navier boundary condition, the Navier-Stokes equation, and the Cahn-Hilliard
interfacial free energy. Our hydrodynamic model yields interfacial and velocity
profiles matching those from the molecular dynamics simulations at the
molecular-scale vicinity of the contact line. In particular, the behavior at
high capillary numbers, leading to the breakup of the fluid-fluid interface, is
accurately predicted.Comment: 33 pages for text in preprint format, 10 pages for 10 figures with
captions, content changed in this resubmissio
On-chip quantum interference between silicon photon-pair sources
Large-scale integrated quantum photonic technologies1, 2 will require on-chip integration of identical photon sources with reconfigurable waveguide circuits. Relatively complex quantum circuits have been demonstrated already1, 2, 3, 4, 5, 6, 7, but few studies acknowledge the pressing need to integrate photon sources and waveguide circuits together on-chip8, 9. A key step towards such large-scale quantum technologies is the integration of just two individual photon sources within a waveguide circuit, and the demonstration of high-visibility quantum interference between them. Here, we report a silicon-on-insulator device that combines two four-wave mixing sources in an interferometer with a reconfigurable phase shifter. We configured the device to create and manipulate two-colour (non-degenerate) or same-colour (degenerate) path-entangled or path-unentangled photon pairs. We observed up to 100.0 ± 0.4% visibility quantum interference on-chip, and up to 95 ± 4% off-chip. Our device removes the need for external photon sources, provides a path to increasing the complexity of quantum photonic circuits and is a first step towards fully integrated quantum technologies
Disjoining Potential and Spreading of Thin Liquid Layers in the Diffuse Interface Model Coupled to Hydrodynamics
The hydrodynamic phase field model is applied to the problem of film
spreading on a solid surface. The disjoining potential, responsible for
modification of the fluid properties near a three-phase contact line, is
computed from the solvability conditions of the density field equation with
appropriate boundary conditions imposed on the solid support. The equation
describing the motion of a spreading film are derived in the lubrication
approximation. In the case of quasi-equilibrium spreading, is shown that the
correct sharp-interface limit is obtained, and sample solutions are obtained by
numerical integration. It is further shown that evaporation or condensation may
strongly affect the dynamics near the contact line, and accounting for kinetic
retardation of the interphase transport is necessary to build up a consistent
theory.Comment: 14 pages, 5 figures, to appear in PR
Asymptotic Giant Branch Variables in the Galaxy and the Local Group
AGB variables, particularly the large amplitude Mira type, are a vital step
on the distance scale ladder. They will prove particularly important in the era
of space telescopes and extremely large ground-based telescopes with adaptive
optics, which will be optimized for infrared observing. Our current
understanding of the distances to these stars is reviewed with particular
emphasis on improvements that came from Hipparcos as well as on recent work on
Local Group galaxies. In addition to providing the essential calibration for
extragalactic distances Gaia may also provide unprecedented insight into the
poorly understood mass-loss process itself.Comment: Accepted for publication in Astrophysics and Space Science. From a
presentation at the conference "The Fundamental Cosmic Distance Scale: State
of the Art and Gaia Perspective, Naples May 2011. 8 Pages, 9 Figure
The value of character-based judgement in the professional domain
Dimensions of character are often overlooked in professional practice at the expense of the development of technical competence and operational efficiency. Drawing on philosophical accounts of virtue ethics and positive psychology, the present work attempts to elevate the role of ‘good’ character in the professional domain. A ‘good’ professional is ideally one that exemplifies dimensions of character informed by sound judgement. A total of 2340 professionals, from five discrete professions, were profiled based on their valuation of qualities pertaining to character and judgement. Profile differences were subsequently examined in the self-reported experience of professional purpose towards a wider societal ‘good’. Analysis of covariance, controlling for stage of career, revealed that professionals valuing character reported higher professional purpose than those overweighting the importance of judgement or valuing neither character nor judgement, F(3, 2054) = 7.92, p < .001. No differences were found between the two groups valuing character, irrespective of whether judgement was valued simultaneously. This profiling analysis of entry-level and in-service professionals, based on their holistic character composition, paves the way for fresh philosophical discussion regarding what constitutes a ‘good’ professional and the interplay between character and judgement. The empirical findings may be of substantive value in helping to recognise how the dimensions of character and judgement may impact upon practitioners’ professional purpose
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