296 research outputs found
PROGRAM ODD--A ONE-DIMENSIONAL MULTIGROUP CODE FOR THE IBM-7090 (ANP PROGRAM NO. 657)
The physical and mathematical reactor models which are used in Program ODD are discussed. In addition, the FORTRAN II source program listings, decimal data input sheets, and input and output for a sample case are given. Program ODD was designed to raake use of the Revised Nuclear Data System at ANPD which consists of twenty-five energy group cross-section data including high energy inelastic scattering matrices, resonance parameters for the resolved resonances, and thermalization scattering matrices for the near thermal energy region. The most unique aspect of the program is the mathematical technique employed for eliminating inner iterations and slow convergenc rates occasioned by the up- scattering'' in the thermalization region of the energy lattice. Direct inversion of the energy matrix coupling the thermal and last four epitherma groups provides simultaneous consistent solutions for thes groups within each power iteration. (auth
Non-perturbative Propagators, Running Coupling and Dynamical Quark Mass of Landau gauge QCD
The coupled system of renormalized Dyson-Schwinger equations for the quark,
gluon and ghost propagators of Landau gauge QCD is solved within truncation
schemes. These employ bare as well as non-perturbative ansaetze for the
vertices such that the running coupling as well as the quark mass function are
independent of the renormalization point. The one-loop anomalous dimensions of
all propagators are reproduced. Dynamical chiral symmetry breaking is found,
the dynamically generated quark mass agrees well with phenomenological values
and corresponding results from lattice calculations. The effects of unquenching
the system are small. In particular the infrared behavior of the ghost and
gluon dressing functions found in previous studies is almost unchanged as long
as the number of light flavors is smaller than four.Comment: 34 pages, 10 figures, version to be published by Phys. Rev.
A p-Spin Interaction Ashkin-Teller Spin-Glass Model
A p-spin interaction Ashkin-Teller spin glass, with three independent
Gaussian probability distributions for the exchange interactions, is studied by
means of the replica method. A simple phase diagram is obtained within the
replica-symmetric approximation, presenting an instability of the paramagnetic
solution at low temperatures. The replica-symmetry-breaking procedure is
implemented and a rich phase diagram is obtained; besides the paramagnetic
phase, three distinct spin-glass phases appear. Three first-order critical
frontiers are found and they all meet at a triple point; among such lines, two
of them present discontinuities in the order parameters, but no latent heat,
whereas the other one exhibits both discontinuities in the order parameters and
a finite latent heat.Comment: 17 pages, 2 figures, submitted to Physica
Analytic properties of the Landau gauge gluon and quark propagators
We explore the analytic structure of the gluon and quark propagators of
Landau gauge QCD from numerical solutions of the coupled system of renormalized
Dyson--Schwinger equations and from fits to lattice data. We find sizable
negative norm contributions in the transverse gluon propagator indicating the
absence of the transverse gluon from the physical spectrum. A simple analytic
structure for the gluon propagator is proposed. For the quark propagator we
find evidence for a mass-like singularity on the real timelike momentum axis,
with a mass of 350 to 500 MeV. Within the employed Green's functions approach
we identify a crucial term in the quark-gluon vertex that leads to a positive
definite Schwinger function for the quark propagator.Comment: 42 pages, 16 figures, revtex; version to be published in Phys Rev
Hepatitis C virus in hemophilia:Health-related quality of life after successful treatment in the sixth Hemophilia in the Netherlands study
INTRODUCTION: Persons with hemophilia and hepatitis C virus (HCV) infection have a lower health‐related quality of life (HRQoL) than those never HCV infected. However, it is unknown whether HRQoL after HCV eradication is comparable to individuals never HCV infected. We aimed to compare HRQoL between HCV‐cured and never chronically HCV‐infected persons with hemophilia. METHODS: All persons with hemophilia in the Netherlands were invited for a nationwide study conducted in 2018–2019. For the current analysis, participants born before 1992 with data on HRQoL and HCV status were included. HCV status was collected from medical records. HRQoL was measured by RAND‐36 questionnaire, with a minimally important difference set at 4.0 points. Multivariable linear regression was used to adjust for age, hemophilia severity, HIV status, and self‐reported joint impairment. RESULTS: In total, 486 persons were eligible; 180 were HCV cured and 306 never chronically HCV infected. Compared with those never HCV infected, HCV‐cured individuals were older (57 vs. 53 years), more often had severe hemophilia (67% vs. 21%), and reported more impaired joints (median 3 vs. 0). Compared with those never HCV infected, adjusted RAND‐36 domain scores of HCV‐cured individuals cured were lower on all RAND‐36 domains except Pain, ranging from a difference of 4.5 (95% CI, −8.8 to −0.3) for Physical functioning to 11.3 (95% CI, −19.4 to −3.1) for Role limitations due to physical problems. CONCLUSION: Despite effective HCV treatment, HRQoL of HCV‐cured persons with hemophilia is still lower than HRQoL of those never chronically HCV‐infected on all RAND‐36 domains. This implies that careful psychosocial follow‐up and support are indicated
PREDICTING THE SUMMER TEMPERATURE OF SMALL STREAMS IN SOUTHWESTERN WISCONSIN 1
One of the biggest challenges in managing cold water streams in the Midwest is understanding how stream temperature is controlled by the complex interactions among meteorologic processes, channel geometry, and ground water inflow. Inflow of cold ground water, shade provided by riparian vegetation, and channel width are the most important factors controlling summer stream temperatures. A simple screening model was used to quantitatively evaluate the importance of these factors and guide management decisions. The model uses an analytical solution to the heat transport equation to predict steady-state temperature throughout a stream reach. The model matches field data from four streams in southwestern Wisconsin quite well (typically within 1°C) and helps explain the observed warming and cooling trends along each stream reach. The distribution of ground water inflow throughout a stream reach has an important influence on stream temperature, and springs are especially effective at providing thermal refuge for fish. Although simple, this model provides insight into the importance of ground water and the impact different management strategies, such as planting trees to increase shade, may have on summer stream temperature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74032/1/j.1752-1688.2005.tb03714.x.pd
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
Relationship of edge localized mode burst times with divertor flux loop signal phase in JET
A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM
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