7,084 research outputs found
Towards variance-matrix characterization of complementarity relations in a continuous variable system
We discuss complementarity relations in a bipartite continuous variable
system. Building up from the work done on discrete d-dimensional systems, we
prove that for symmetric two-mode states, quantum complementarity relations can
be put in a simple relation with the elements of the variance matrix. When this
condition is not satisfied, such a connection becomes non-trivial. Our
investigation is the first step towards an operative characterization of the
complementarity in a scenario that has not been investigated so far.Comment: 7 pages, 4 figures, RevTeX
Particle and particle pair dispersion in turbulence modeled with spatially and temporally correlated stochastic processes
In this paper we present a new model for modeling the diffusion and relative
dispersion of particles in homogeneous isotropic turbulence. We use an
Heisenberg-like Hamiltonian to incorporate spatial correlations between fluid
particles, which are modeled by stochastic processes correlated in time. We are
able to reproduce the ballistic regime in the mean squared displacement of
single particles and the transition to a normal diffusion regime for long
times. For the dispersion of particle pairs we find a -dependence of the
mean squared separation at short times and a -dependence for long ones. For
intermediate times indications for a Richardson law are observed in
certain situations. Finally the influence of inertia of real particles on the
dispersion is investigated.Comment: 10 pages, 7 figures, 1 tabl
Mass Loss of and Temperature Distribution in Southern Pine and Douglas Fir in the Range 100 To 800°C
Southern pine and Douglas fir test specimens were placed in an over kept at either 100, 160, 245, 400, 600, or 800 °C, and the center point temperatures and the mass losses of the specimens were measured as functions of exposure time. A model is described for calculating the temperature distribution in and the mass loss of wooden beams having rectangular cross sections. Comparisons were made between the data and the results of the model, and reasonable agreements were found between the measured and calculated temperatures and mass losses. Some tests were also performed to assess the effect of ambient oxygen concentration on the mass loss.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68991/2/10.1177_073490418300100405.pd
Measurement of the thermal conductivity of helium up to 2100°K by the column method
The thermal conductivity of helium was measured at atmospheric pressure in the range 800–2100°K by the column method. The data could be correlated by the polynomial λ = 0.635×10−1+0.310×10−3T−0.244×10−7T2λ=0.635×10−1+0.310×10−3T−0.244×10−7T2, where λ is in watts per meters degrees Kelvin and T is in degrees Kelvin. The results obtained were compared with previous thermal conductivity measurements. The data of Desmond and Saxena and Saxena agree closely with the present results; the data of Timrot and Umanskii appear to be too low and those of Blais and Mann too high. Values for f = λ/ηCvf=λ∕ηCv, computed using measured thermal conductivities and available viscosity data, were found to agree well with classical results from kinetic theory.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70040/2/JCPSA6-58-10-4080-1.pd
Attitudes of Austrian veterinarians towards euthanasia in small animal practice: Impacts of age and gender on views on euthanasia
Background: Euthanasia of pets has been described by veterinarians as "the best and the worst" of the profession. The most commonly mentioned ethical dilemmas veterinarians face in small animal practice are: limited treatment options due to financial constraints, euthanizing of healthy animals and owners wishing to continue treatment of terminally ill animals. The aim of the study was to gain insight into the attitudes of Austrian veterinarians towards euthanasia of small animals. This included assessing their agreement with euthanasia in exemplified case scenarios, potentially predicted by demographic variables (e.g. gender, age, working in small animal practice, employment, working in a team, numbers of performed euthanasia). Further describing the veterinarians' agreement with a number of different normative and descriptive statements, including coping strategies. A questionnaire with nine euthanasia scenarios, 26 normative and descriptive statements, and demographic data were sent to all members of the Austrian Chamber of Veterinary Surgeons (n = 2478). Results: In total, 486 veterinarians answered sufficiently completely to enable analyses. Responses were first explored descriptively before being formally analysed using linear regression and additive Bayesian networks - a multivariate regression methodology - in order to identify joint relationships between the demographic variables, the statements and each of the nine euthanasia scenarios. Mutual dependencies between the demographic variables were found, i.e. female compared to male veterinarians worked mostly in small animal practice, and working mostly in small animal practice was linked to performing more euthanasia per month. Conclusions: Gender and age were found to be associated with views on euthanasia: female veterinarians and veterinarians having worked for less years were more likely to disagree with euthanasia in at least some of the convenience euthanasia scenarios. The number of veterinarians working together was found to be the variable with the highest number of links to other variables, demographic as well as ethical statements. This highlights the role of a team potentially providing support in stressful situations. The results are useful for a better understanding of coping strategies for veterinarians with moral stress due to euthanasia of small animals
Quantum affine Cartan matrices, Poincare series of binary polyhedral groups, and reflection representations
We first review some invariant theoretic results about the finite subgroups
of SU(2) in a quick algebraic way by using the McKay correspondence and quantum
affine Cartan matrices. By the way it turns out that some parameters
(a,b,h;p,q,r) that one usually associates with such a group and hence with a
simply-laced Coxeter-Dynkin diagram have a meaningful definition for the
non-simply-laced diagrams, too, and as a byproduct we extend Saito's formula
for the determinant of the Cartan matrix to all cases. Returning to invariant
theory we show that for each irreducible representation i of a binary
tetrahedral, octahedral, or icosahedral group one can find a homomorphism into
a finite complex reflection group whose defining reflection representation
restricts to i.Comment: 19 page
Purification, growth, and characterization of Zn(x)Cd(1-x)Se crystals
The purification of starting materials which were used in the growth of Zn(x)Cd(1-x)Se (x = 0.2) single crystals using the traveling solution method (TSM) is reported. Up to 13 cm long single crystals and as grown resistivities of 6 x 10(exp 12) ohm/cm could be achieved. Infrared and Raman spectra of Zn(0.2)Cd(0.8)Se are also presented and discussed
On spherical twisted conjugacy classes
Let G be a simple algebraic group over an algebraically closed field of good
odd characteristic, and let theta be an automorphism of G arising from an
involution of its Dynkin diagram. We show that the spherical theta-twisted
conjugacy classes are precisely those intersecting only Bruhat cells
corresponding to twisted involutions in the Weyl group. We show how the
analogue of this statement fails in the triality case. We generalize to good
odd characteristic J-H. Lu's dimension formula for spherical twisted conjugacy
classes.Comment: proof of Lemma 6.4 polished. The journal version is available at
http://www.springerlink.com/content/k573l88256753640
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