3,769 research outputs found
Stability of Isometric Strength Asymmetry and Its Relationship to Sprint and Change-of-Direction Performance Asymmetry in Division-I Collegiate Athletes
The purpose of this dissertation was to evaluate the stability of strength asymmetry over a long-term period (1 year) and investigate the relationship of strength asymmetry to field test performance asymmetry in NCAA division-1 athletes. Isometric mid-thigh pull (IMTP) peak force asymmetry, ground contact time and finish time asymmetries on 10m sprint and 505 agility test performances were also observed. The impact of strength was also investigated in these studies to determine its effect on the magnitude of asymmetry.
In the second study, peak force asymmetry over a one-year period was observed to be a rather volatile quality, with ranges between 16% or 8%, depending on the formula used. Based on this finding, it is possible that there may be a “normal” range of asymmetry that an individual athlete exhibits that could be linked to training adaptations along with other factors. Based on simple observation, an individual tendency toward symmetry existed in certain athletes. This relationship may be useful to explore in future study
Reevaluating the California Sales Tax: Exemptions, Equity, Effectiveness, and the Need for a Broader Base
This Comment examines the tax base and administrative aspects of the sales tax in California and argues the need for reform. It analyzes the State\u27s sales tax system against its original goals and attempts to measure the tax system\u27s success. The analysis points to the proliferation of exclusions and exemptions that reduce the efficacy and equity of the tax system and clearly demonstrates a need to expand the tax base if the system is to remain true to its original goals and remain a strong source of revenue for the state. The Comment also discuss alternative taxation schemes, focusing both on simplifying the tax structure through the taxation of selected services and decreasing the number of exemptions, as well as exploring the possibility of a wholesale revision of the taxing system
Consideration of radar target glint from ST during OMV rendezvous
The nature of radar target glint and the factors upon which it depends when using the Hubble Space Telescope as a radar target is discussed. An analysis of the glint problem using a 35 MHz or 94 MHz radar on the orbital maneuvering vehicle is explored. A strategy for overcoming glint is suggested
Covariant quantum measurements may not be optimal
Quantum particles, such as spins, can be used for communicating spatial
directions to observers who share no common coordinate frame. We show that if
the emitter's signals are the orbit of a group, then the optimal detection
method may not be a covariant measurement (contrary to widespread belief). It
may be advantageous for the receiver to use a different group and an indirect
estimation method: first, an ordinary measurement supplies redundant numerical
parameters; the latter are then used for a nonlinear optimal identification of
the signal.Comment: minor corrections, to appear in J. Mod. Opt. (proc. of Gdansk conf.
Probabilities from envariance?
Zurek claims to have derived Born's rule noncircularly in the context of an
ontological no-collapse interpretation of quantum states, without any "deus ex
machina imposition of the symptoms of classicality." After a brief review of
Zurek's derivation it is argued that this claim is exaggerated if not wholly
unjustified. In order to demonstrate that Born's rule arises noncircularly from
deterministically evolving quantum states, it is not sufficient to assume that
quantum states are somehow associated with probabilities and then prove that
these probabilities are given by Born's rule. One has to show how irreducible
probabilities can arise in the context of an ontological no-collapse
interpretation of quantum states. It is argued that the reason why all attempts
to do this have so far failed is that quantum states are fundamentally
algorithms for computing correlations between possible measurement outcomes,
rather than evolving ontological states.Comment: To appear in IJQI; 9 pages, LaTe
Investigation into the Formation and Adhesion of Cyclopentane Hydrates on Mechanically Robust Vapor-Deposited Polymeric Coatings
Blockage of pipelines by formation and accumulation of clathrate hydrates of natural gases (also called gas hydrates) can compromise project safety and economics in oil and gas operations, particularly at high pressures and low temperatures such as those found in subsea or arctic environments. Cyclopentane (CyC5) hydrate has attracted interest as a model system for studying natural gas hydrates, because CyC5, like typical natural gas hydrate formers, is almost fully immiscible in water; and thus CyC5 hydrate formation is governed not only by thermodynamic phase considerations but also kinetic factors such as the hydrocarbon/water interfacial area, as well as mass and heat transfer constraints, as for natural gas hydrates. We present a macroscale investigation of the formation and adhesion strength of CyC5 hydrate deposits on bilayer polymer coatings with a range of wettabilities. The polymeric bilayer coatings are developed using initiated chemical vapor deposition (iCVD) of a mechanically robust and densely cross-linked polymeric base layer (polydivinylbenzene or pDVB) that is capped with a covalently attached thin hydrate-phobic fluorine-rich top layer (poly(perfluorodecyl acrylate) or pPFDA). The CyC5 hydrates are formed from CyC5-in-water emulsions, and differential scanning calorimetry (DSC) is used to confirm the thermal dissociation properties of the solid hydrate deposits. We also investigate the adhesion of the CyC5 hydrate deposits on bare and bilayer polymer-coated silicon and steel substrates. Goniometric measurements with drops of CyC5-in-water emulsions on the coated steel substrates exhibit advancing contact angles of 148.3 ± 4.5° and receding contact angles of 142.5 ± 9.8°, indicating the strongly emulsion-repelling nature of the iCVD coatings. The adhesion strength of the CyC5 hydrate deposits is reduced from 220 ± 45 kPa on rough steel substrates to 20 ± 17 kPa on the polymer-coated steel substrates. The measured strength of CyC5 hydrate adhesion is found to correlate very well with the work of adhesion between the emulsion droplets used to form the CyC5 hydrate and the underlying substrates
From Classical to Quantum Mechanics: "How to translate physical ideas into mathematical language"
In this paper, we investigate the connection between Classical and Quantum
Mechanics by dividing Quantum Theory in two parts: - General Quantum Axiomatics
(a system is described by a state in a Hilbert space, observables are
self-adjoint operators and so on) - Quantum Mechanics properly that specifies
the Hilbert space, the Heisenberg rule, the free Hamiltonian... We show that
General Quantum Axiomatics (up to a supplementary "axiom of classicity") can be
used as a non-standard mathematical ground to formulate all the ideas and
equations of ordinary Classical Statistical Mechanics. So the question of a
"true quantization" with "h" must be seen as an independent problem not
directly related with quantum formalism. Moreover, this non-standard
formulation of Classical Mechanics exhibits a new kind of operation with no
classical counterpart: this operation is related to the "quantization process",
and we show why quantization physically depends on group theory (Galileo
group). This analytical procedure of quantization replaces the "correspondence
principle" (or canonical quantization) and allows to map Classical Mechanics
into Quantum Mechanics, giving all operators of Quantum Mechanics and
Schrodinger equation. Moreover spins for particles are naturally generated,
including an approximation of their interaction with magnetic fields. We find
also that this approach gives a natural semi-classical formalism: some exact
quantum results are obtained only using classical-like formula. So this
procedure has the nice property of enlightening in a more comprehensible way
both logical and analytical connection between classical and quantum pictures.Comment: 47 page
Burnout After Patient Death: Challenges for Direct Care Workers.
Direct care workers in long-term care can develop close relationships with their patients and subsequently experience significant grief after patient death. Consequences of this experience for employment outcomes have received little attention.
To investigate staff, institutional, patient, and grief factors as predictors of burnout dimensions among direct care workers who had experienced recent patient death; determine which specific aspects of these factors are of particular importance; and establish grief as an independent predictor of burnout dimensions.
Participants were 140 certified nursing assistants and 80 homecare workers who recently experienced patient death. Data collection involved comprehensive semistructured in-person interviews. Standardized assessments and structured questions addressed staff, patient, and institutional characteristics, grief symptoms and grief avoidance, as well as burnout dimensions (depersonalization, emotional exhaustion, and personal accomplishment).
Hierarchical regressions revealed that grief factors accounted for unique variance in depersonalization, over and above staff, patient, and institutional factors. Supervisor support and caregiving benefits were consistently associated with higher levels on burnout dimensions. In contrast, coworker support was associated with a higher likelihood of depersonalization and emotional exhaustion.
Findings suggest that grief over patient death plays an overlooked role in direct care worker burnout. High supervisor support and caregiving benefits may have protective effects with respect to burnout, whereas high coworker support may constitute a reflection of burnout
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