6,138 research outputs found
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
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
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
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
Postpartum Safety and Satisfaction Following Early Discharge
Two Ontario sites were involved in the evaluation of an obstetrical discharge program. Before program implementation a group of eligible women were enrolled as the preprogram control group (n = 542). During the program, eligible women who agreed to early discharge (ED) became the ED group (n = 319), and those opting not to go home early but consenting to participate in the evaluation became the concurrent group (n = 456). All groups were mailed a self-administered postpartum questionnaire. On demographic characteristics, safety and satisfaction, the ED group was comparable to the concurrent group. Hospital readmission rates did not differ across groups after stratification by site or hospital. Multiple classification analyses revealed a similar pattern for overall satisfaction levels. This unique ED program, which allowed pre- or postnatal enrollment and did not require an initial home assessment, appears to be a safe, effective and flexible approach to obstetrical care
Gender Differences In Reading And Math Scores On The Pennsylvania System of School Assessment Grade Five And Grade Eight Tests
Analysis of SPAR 8 single-axis levitation experiment
The melting and resolidification of SPAR 8 payload melting and resolidification of a glass specimen from the in a containerless condition and the retrieval and examination of the specimen from the. The absence of container contact was assured by use of a single-axis acoustic levitation system. However, the sample contacted a wire cage after being held without container contact by the acoustic field for only approximately 87 seconds. At this time, the sample was still molten and, therefore, flowed aroung the wire and continued to adhere to it. An analysis of why the sample did not remain levitated free of container contact is presented. The experiment is described, and experimental observations are discussed and analyzed
Urban environmental health applications of remote sensing
An urban area was studied through the use of the inventory-by-surrogate method rather than by direct interpretation of photographic imagery. Prior uses of remote sensing in urban and public research are examined. The effects of crowding, poor housing conditions, air pollution, and street conditions on public health are considered. Color infrared photography was used to categorize land use features and the grid method was used in photo interpretation analysis. The incidence of shigella and salmonella, hepatitis, meningitis, tuberculosis, myocardial infarction and veneral disease were studied, together with mortality and morbidity rates. Sample census data were randomly collected and validated. The hypothesis that land use and residential quality are associated with and act as an influence upon health and physical well-being was studied and confirmed
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