35,232 research outputs found
Studying pion effects on the chiral phase transition
We investigate the chiral phase transition at finite temperatures and zero
chemical potential with Dyson-Schwinger equations. Our truncation for the
quark-gluon interaction includes mesonic degrees of freedom, which allows us to
study the impact of the pions on the nature of the phase transition. Within the
present scheme we find a five percent change of the critical temperature due to
the pion backreaction whereas the mean field character of the transition is not
changed.Comment: 2 pages, 2 figures, talk given by J.A.M. at the 30th International
School of Nuclear Physics, Erice, Sicily from 16 - 24 September 200
Fluctuation dynamo amplified by intermittent shear bursts in convectively driven magnetohydrodynamic turbulence
Intermittent large-scale high-shear flows are found to occur frequently and
spontaneously in direct numerical simulations of statistically stationary
turbulent Boussinesq magnetohydrodynamic (MHD) convection. The energetic
steady-state of the system is sustained by convective driving of the velocity
field and small-scale dynamo action. The intermittent emergence of flow
structures with strong velocity and magnetic shearing generates magnetic energy
at an elevated rate over time-scales longer than the characteristic time of the
large-scale convective motion. The resilience of magnetic energy amplification
suggests that intermittent shear-bursts are a significant driver of dynamo
action in turbulent magnetoconvection
Are Consumers Indeed Misled? Congruency in Consumers' Attitudes towards Wine Labeling Information versus Revealed Preferences from a Choice Experiment
Please Contact Authors for Updated Version before Citingdiscrete choice experiment vs. attitude measurement, food labeling, willingness to pay, consumers, wine, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Marketing,
Pairing, Ferromagnetism, and Condensation of a normal spin-1 Bose gas
We theoretically study the stability of a normal, spin disordered, homogenous
spin-1 Bose gas against ferromagnetism, pairing, and condensation through a
Random Phase Approximation which includes exchange (RPA-X). Repulsive
spin-independent interactions stabilize the normal state against both
ferromagnetism and pairing, and for typical interaction strengths leads to a
direct transition from an unordered normal state to a fully ordered single
particle condensate. Atoms with much larger spin-dependent interaction may
experience a transition to a ferromagnetic normal state or a paired superfluid,
but, within the RPA-X, there is no instability towards a normal state with
spontaneous nematic order. We analyze the role of the quadratic Zeeman effect
and finite system size.Comment: 4 pages, 3 figures, 1 table. Supplementary materials attache
Matrix partitioning and EOF/principal component analysis of Antarctic Sea ice brightness temperatures
A field of measured anomalies of some physical variable relative to their time averages, is partitioned in either the space domain or the time domain. Eigenvectors and corresponding principal components of the smaller dimensioned covariance matrices associated with the partitioned data sets are calculated independently, then joined to approximate the eigenstructure of the larger covariance matrix associated with the unpartitioned data set. The accuracy of the approximation (fraction of the total variance in the field) and the magnitudes of the largest eigenvalues from the partitioned covariance matrices together determine the number of local EOF's and principal components to be joined by any particular level. The space-time distribution of Nimbus-5 ESMR sea ice measurement is analyzed
Using Best-Worst Scaling to Determine Market Channel Choice by Small Farmers in Indonesia
A household survey and a novel Best-Worst scaling method are used to examine the relative importance of various buyer characteristics to small potato farmers in Indonesia. A Latent Class Cluster Analysis is used explore whether producersâ utilities for marketing channels are heterogeneous. For the aggregate sample, the attributes related to the buyer providing immediate cash payment, a price premium and always following through on their commitment to buy their potatoes were the three most important attributes. The results of the Latent Class Cluster Analysis found four unique classes or segments of producers, each with distinct utilities for buyer characteristics and interesting differences socio-demographic characteristics. The largest segment (44%) was relatively similar to the aggregate, placing a high importance on cash payment, price and willingness to negotiate. Two segments, 24% and 16% of producers placed a relatively high importance on the buyer providing access to certified potato seed or finance for purchasing inputs, and another segment placed the highest importance on having a long-term relationship with their buyer. This has interesting implications for traders, particularly traders who are interested in securing a long-term relationship with potato producers â simply being able to provide cash at the time potatoes are delivered and/or a small premium may immediately increase the strength of the relationship.Best-Worst Scaling, Latent Class Cluster Analysis, marketing channel choice, Indonesia, potato farmers, small farmers, Marketing,
Many-body physics in the radio frequency spectrum of lattice bosons
We calculate the radio-frequency spectrum of a trapped cloud of cold bosonic
atoms in an optical lattice. Using random phase and local density
approximations we produce both trap averaged and spatially resolved spectra,
identifying simple features in the spectra that reveal information about both
superfluidity and correlations. Our approach is exact in the deep Mott limit
and in the deep superfluid when the hopping rates for the two internal spin
states are equal. It contains final state interactions, obeys the Ward
identities (and the associated conservation laws), and satisfies the -sum
rule. Motivated by earlier work by Sun, Lannert, and Vishveshwara [Phys. Rev. A
\textbf{79}, 043422 (2009)], we also discuss the features which arise in a
spin-dependent optical lattice.Comment: 6 pages, 4 figures, 13 subfigure
Wind-tunnel tests on a 3-dimensional fixed-geometry scramjet inlet at M = 2.30 to 4.60
Wind-tunnel tests were conducted on a baseline scramjet inlet model having fixed geometry and swept leading edges at M = 2.30, 2.96, 3.95, and 4.60 in the Langley unitary plan wind tunnel. The unit Reynolds number of the tests was held constant at 6.56 million per meter (2 million per foot). The objectives of the tests were to establish inlet performance and starting characteristics in the lower Mach number range of operation (less than M = 5). Surface pressures obtained on the inlet components are presented, along with the results of the internal flow surveys made at the throat and capture stations of the inlet. Contour plots of the inlet-flow-field parameters such as Mach numbers, pressure recovery, flow capture, local static and total pressure ratios at the survey stations are shown for the test Mach numbers
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