4,393 research outputs found
Tool repairs tube components in situ
Two versions of a portable tool repair the seats of tube fittings and the flared ends of tubing. Each version operates on the principle of lapping to remove imperfections from tube and fitting interfacing surfaces
A study of two-body strong interactions of elementary particles Final technical report, 27 Jan. 1969 - 1 May 1970
Two-body strong interactions of elementary particles including kaons, pions, hyperons, and proton
Classical-quantum correspondence in bosonic two-mode conversion systems: polynomial algebras and Kummer shapes
Bosonic quantum conversion systems can be modeled by many-particle
single-mode Hamiltonians describing a conversion of molecules of type A
into molecules of type B and vice versa. These Hamiltonians are analyzed in
terms of generators of a polynomially deformed algebra. In the
mean-field limit of large particle numbers, these systems become classical and
their Hamiltonian dynamics can again be described by polynomial deformations of
a Lie algebra, where quantum commutators are replaced by Poisson brackets. The
Casimir operator restricts the motion to Kummer shapes, deformed Bloch spheres
with cusp singularities depending on and . It is demonstrated that the
many-particle eigenvalues can be recovered from the mean-field dynamics using a
WKB type quantization condition. The many-particle state densities can be
semiclassically approximated by the time-periods of periodic orbits, which show
characteristic steps and singularities related to the fixed points, whose
bifurcation properties are analyzed.Comment: 13 pages, 13 figure
Quasiclassical analysis of Bloch oscillations in non-Hermitian tight-binding lattices
Many features of Bloch oscillations in one-dimensional quantum lattices with
a static force can be described by quasiclassical considerations for example by
means of the acceleration theorem, at least for Hermitian systems. Here the
quasiclassical approach is extended to non-Hermitian lattices, which are of
increasing interest. The analysis is based on a generalised non-Hermitian phase
space dynamics developed recently. Applications to a single-band tight-binding
system demonstrate that many features of the quantum dynamics can be understood
from this classical description qualitatively and even quantitatively. Two
non-Hermitian and -symmetric examples are studied, a Hatano-Nelson lattice
with real coupling constants and a system with purely imaginary couplings, both
for initially localised states in space or in momentum. It is shown that the
time-evolution of the norm of the wave packet and the expectation values of
position and momentum can be described in a classical picture.Comment: 20 pages, 8 figures, typos corrected, slightly extended, accepted for
publication in New Journal of Physics in Focus Issue on Parity-Time Symmetry
in Optics and Photonic
A Global Hypothesis for Women in Journalism and Mass Communications: The Ratio of Recurrent and Reinforced Residuum
This paper examines the status of women in communications industries and on university faculties. It specifically tests the Ratio of Recurrent and Reinforced Residuum or R3 hypothesis, as developed by Rush in the early 1980s [Rush, Buck & Ogan,1982]. The R3 hypothesis predicts that the percentage of women in the communications industries and on university faculties will follow the ratio residing around 1/4:3/4 or 1/3:2/3 proportion females to males. This paper presents data from a nationwide U.S. survey and compares them to data from global surveys and United Nations reports. The evidence is overwhelming and shows the relevance and validity of the R3 hypothesis across different socio-economic and cultural contexts. The paper argues that the ratio is the outcome of systemic discrimination that operates at multiple levels. The obstacles to achieving equality in the academy as well as media industries are discussed and suggestions for breaking out of the R3 ratio are included.
A Global Hypothesis for Women in Journalism and Mass Communications: The Ratio of Recurrent and Reinforced Residuum
This paper examines the status of women in communications industries and on university faculties. It specifically tests the Ratio of Recurrent and Reinforced Residuum or R3 hypothesis, as developed by Rush in the early 1980s [Rush, Buck & Ogan,1982]. The R3 hypothesis predicts that the percentage of women in the communications industries and on university faculties will follow the ratio residing around 1/4:3/4 or 1/3:2/3 proportion females to males. This paper presents data from a nationwide U.S. survey and compares them to data from global surveys and United Nations reports. The evidence is overwhelming and shows the relevance and validity of the R3 hypothesis across different socio-economic and cultural contexts. The paper argues that the ratio is the outcome of systemic discrimination that operates at multiple levels. The obstacles to achieving equality in the academy as well as media industries are discussed and suggestions for breaking out of the R3 ratio are included.
Whither Sexual Orientation Analysis?: The Proper Methodology When Due Process and Equal Protection Intersect
This Article suggests that there is Proper Methodology that courts apply when reviewing cases at the intersection of due process and equal protection. Briefly, courts operate under a rule that heightened review applies if either a fundamental right or a suspect class is involved in a case, and that rational basis review applies if neither is involved (the Rule ). Two primary exceptions to the Rule exist, and this Article identifies them as the Logical and Ill Motives Exceptions. The Logical Exception applies when a court need not apply heightened review because a law fails rational basis review. The Ill Motives Exception applies when a law fails rational basis review because the sole purpose behind a law is an ill motive. The Rule and the Exceptions provide the Proper Methodology to be applied in intersection cases. The genesis for the Article arose in the context of analyzing the constitutionality of laws that ban marriage between persons of the same sex, popularly called gay marriage. Notwithstanding the fact that the right to marry is a fundamental right, confusion exists as to whether gay marriage bans are subject to rational basis review or heightened scrutiny. Some of the confusion exists because the Supreme Court has not decided where sexual orientation fits in the equal protection paradigm. But this void is responsible for only part of the confusion. This Article exposes another dangerous source of confusion-a tendency to allow popular discourse to shape the legal analysis in sexual orientation discrimination cases, resulting in what this Article calls the Collapsible Error. Courts commit the Collapsible Error when they conflate the equal protection question ( Are gays a suspect class? ) into the due process question ( Is there an underlying fundamental right? ) by defining the underlying right by the group targeted by the law-gay marriage-and then limiting the analysis to substantive due process ( Is there a fundamental right to gay marriage? ). This Article explores why committing the Collapsible Error is a denial of the due process and equal protection rights of gays because it results in an unjustifiable deviation from the Proper Methodology that is applied in cases involving other types of discrimination. Understanding and applying the Proper Methodology is not only a matter of judicial integrity, but it also is an opportunity to bring gays into the Constitution\u27s fold
Development of a Low-Noise High Common-Mode-Rejection Instrumentation Amplifier
Several previously used instrumentation amplifier circuits were examined to find limitations and possibilities for improvement. One general configuration is analyzed in detail, and methods for improvement are enumerated. An improved amplifier circuit is described and analyzed with respect to common mode rejection and noise. Experimental data are presented showing good agreement between calculated and measured common mode rejection ratio and equivalent noise resistance. The amplifier is shown to be capable of common mode rejection in excess of 140 db for a trimmed circuit at frequencies below 100 Hz and equivalent white noise below 3.0 nv/square root of Hz above 1000 Hz
Projective equivalence of ideals in Noetherian integral domains
Let I be a nonzero proper ideal in a Noetherian integral domain R. In this
paper we establish the existence of a finite separable integral extension
domain A of R and a positive integer m such that all the Rees integers of IA
are equal to m. Moreover, if R has altitude one, then all the Rees integers of
J = Rad(IA) are equal to one and the ideals J^m and IA have the same integral
closure. Thus Rad(IA) = J is a projectively full radical ideal that is
projectively equivalent to IA. In particular, if R is Dedekind, then there
exists a Dedekind domain A having the following properties: (i) A is a finite
separable integral extension of R; and (ii) there exists a radical ideal J of A
and a positive integer m such that IA = J^m.Comment: 20 page
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