8,782 research outputs found
Daze fasteners
A daze fastener system for connecting two or more structural elements wherein the structural elements and fastener parts have substantially different coefficient of thermal expansion physical property characteristics is employed in this invention. By providing frusto-conical abutting surfaces between the structural elements and fastener parts any differences in thermal expansion/contraction between the parts is translated to sliding motion and avoids deleterious thermal stresses in the connection. An essential feature for isotropic homogeneous material connections is that at least two sets of mating surfaces are required wherein each set of mating surfaces have line element extensions that pass through a common point
The Multiple Meanings of Rock Music During the Vietnam War
Undergraduate
Textual or Investigativ
Poynting Vector Flow in a Circular Circuit
A circuit is considered in the shape of a ring, with a battery of negligible
size and a wire of uniform resistance. A linear charge distribution along the
wire maintains an electrostatic field and a steady current, which produces a
constant magnetic field. Earlier studies of the Poynting vector and the rate of
flow of energy considered only idealized geometries in which the Poynting
vector was confined to the space within the circuit. But in more realistic
cases the Poynting vector is nonzero outside as well as inside the circuit. An
expression is obtained for the Poynting vector in terms of products of
integrals, which are evaluated numerically to show the energy flow. Limiting
expressions are obtained analytically. It is shown that the total power
generated by the battery equals the energy flowing into the wire per unit time.Comment: 19 pages, 8 figure
Comment on 'Helmholtz theorem and the v-gauge in the problem of superluminal and instantaneous signals in classical electrodynamics,' by Chubykalo et al [Found. of Phys. Lett, 19, 37-46 (2006)]
Fundamental errors in the Chubykalo et al paper [Found. of Phys. Lett, 19,
37-46 (2006)] are highlighted. Contrary to their claim that "... the
irrotational component of the electric field has a physical meaning and can
propagate exclusively instantaneously," it is shown that this instantaneous
component is physically irrelevant because it is always canceled by a term
contained into the solenoidal component. This result follows directly from the
solution of the wave equation that satisfies the solenoidal component.
Therefore the subsequent inference of these authors that there are two
mechanisms of transmission of energy and momentum in classical electrodynamics,
one retarded and the other one instantaneous, has no basis. The example given
by these authors in which the full electric field of an oscillating charge
equals its instantaneous irrotational component on the axis of oscillations is
proved to be false.Comment: An alternative discussion can be found in the paper: Jose A. Heras,
"How potentials in different gauges yield the same retarded electric and
magnetic fields," Am. J. Phys. 75, 176-183 (2007
Seasonal availability and distribution of benthic fishes of Chesapeake Bight
In considering the potential for expanding the Middle Atlantic fishery, Virginia Institute of Marine Science estimated the seasonal distribution and availability of benthic fishes on the 15,000 square miles of continental shelf between Cape Hatteras and Cape May. The survey, which started in the winter of 1966 and continued through the winter of 1968, was conducted in two phases. The ·work in 1966 ·was devoted to determining the seasonal distribution of the various kinds of fishes, especially those which appeared to be under-utilized. For.this work a 45-foot semi-balloon shrimp trawl was employed to make 295 tows which were divided among the four seasons. In the second phase, conducted in 1967 and 1968, the objcctive·was to estimate the quantity of fish potentially available to trawlers, should a market be developed
Trends in delirium coding rates in older hospital inpatients in England and Scotland: full population data comprising 7.7M patients per year show substantial increases between 2012 and 2020
Background: Little information is available on change in delirium coding rates over time in major healthcare systems. We examined trends in delirium discharge coding rates in older patients in hospital admissions to the National Health Service (NHS) in England and Scotland between 2012 and 2020. /
Methods: Hospital administrative coding data were sourced from NHS Digital England and Public Health Scotland. We examined rates of delirium (F05 from ICD-10) in patients aged ≥70 years in 5 year and ≥90 age bands. /
Results: There were approximately 7,000,000 discharges/year in England and 700,000/year in Scotland. Substantially increased delirium coding was observed for all age bands between 2012/2013 and 2019/2020 (p<0.001, Mann Kendall’s tau). In the ≥90 age band, there was a 4-fold increase between 2012 and 2020. /
Conclusion: Delirium coding rates have shown large increases in the NHS in England and Scotland, likely reflecting several factors including policy initiatives, detection tool implementation and education
Trends in delirium coding rates in older hospital inpatients in England and Scotland:full population data comprising 7.7M patients per year show substantial increases between 2012 and 2020
BackgroundLittle information is available on change in delirium coding rates over time in major healthcare systems. We examined trends in delirium discharge coding rates in older patients in hospital admissions to the National Health Service (NHS) in England and Scotland between 2012 and 2020.MethodsHospital administrative coding data were sourced from NHS Digital England and Public Health Scotland. We examined rates of delirium (F05 from ICD-10) in patients aged ≥70 years in 5 year and ≥90 age bands.ResultsThere were approximately 7,000,000 discharges/year in England and 700,000/year in Scotland. Substantially increased delirium coding was observed for all age bands between 2012/2013 and 2019/2020 (p<0.001, Mann Kendall’s tau). In the ≥90 age band, there was a 4-fold increase between 2012 and 2020.ConclusionDelirium coding rates have shown large increases in the NHS in England and Scotland, likely reflecting several factors including policy initiatives, detection tool implementation and education
Special Theory of Relativity through the Doppler Effect
We present the special theory of relativity taking the Doppler effect as the
starting point, and derive several of its main effects, such as time dilation,
length contraction, addition of velocities, and the mass-energy relation, and
assuming energy and momentum conservation, we discuss how to introduce the
4-momentum in a natural way. We also use the Doppler effect to explain the
"twin paradox", and its version on a cylinder. As a by-product we discuss
Bell's spaceship paradox, and the Lorentz transformation for arbitrary
velocities in one dimension.Comment: 20 pages, 1 figur
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