2,569 research outputs found
Yang-Yang thermodynamics on an atom chip
We investigate the behavior of a weakly interacting nearly one-dimensional
(1D) trapped Bose gas at finite temperature. We perform in situ measurements of
spatial density profiles and show that they are very well described by a model
based on exact solutions obtained using the Yang-Yang thermodynamic formalism,
in a regime where other, approximate theoretical approaches fail. We use
Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to
probe the axial momentum distribution of the gas, and find good agreement with
the in situ results.Comment: extended introduction and conclusions, and minor changes throughout;
accepted for publication in Phys. Rev. Let
Yang-Yang thermodynamics on an atom chip
We investigate the behavior of a weakly interacting nearly one-dimensional
(1D) trapped Bose gas at finite temperature. We perform in situ measurements of
spatial density profiles and show that they are very well described by a model
based on exact solutions obtained using the Yang-Yang thermodynamic formalism,
in a regime where other, approximate theoretical approaches fail. We use
Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to
probe the axial momentum distribution of the gas, and find good agreement with
the in situ results.Comment: extended introduction and conclusions, and minor changes throughout;
accepted for publication in Phys. Rev. Let
Stability and electronic structure of the complex KPtCl structure-type hydrides
The stability and bonding of the ternary complex KPtCl structure
hydrides is discussed using first principles density functional calculations.
The cohesion is dominated by ionic contributions, but ligand field effects are
important, and are responsible for the 18-electron rule. Similarities to oxides
are discussed in terms of the electronic structure. However, phonon
calculations for SrRuH also show differences, particularly in the
polarizability of the RuH octahedra. Nevertheless, the yet to be made
compounds PbRuH and BeFeH are possible ferroelectrics. The
electronic structure and magnetic properties of the decomposition product,
FeBe are reported. Implications of the results for H storage are discussed
THE CORRELATION OF MUSCLE FIBER AND PERIMYSIUM THICKNESS TO THE QUALITY OF TURKEY BREAST MEAT
Turkey meat is one kind of poultry meat which gives contribute for consumer meat demand. Germany as a second exporter of turkey meat has always improving the quality of turkey meat. One of the important attribute which play main role in meat quality is tenderness. The objectives of the research were to measure of muscle fiber and perimysium of two male turkeys in particular amount then makes comparison of the measurement between them. Tracing identifying factors which have strong influence to the tenderness of turkey meat also was done. The data also supported by the values from pH, EC, color, drip loss, grill loss, and shear force. Hybrid XL and Big 6 as two lines of genetically turkeys was used in this study. They lines have different weight in part of carcass where Hybrid XL is bigger than Big 6. Concerning to the diameter of muscle fiber, Hybrid XL has smaller diameter than Big 6. The type of muscle fiber in turkey meat is II B. The analysis of the data was used software Statistic 10.0 ed. The results showed that pH value gives influences to the meat colour. L* would be increasing when pH value was decreasing and meat color turning pale. L* determined by amount of myoglobin inside of meat. The other factors were influenced each other concerning the tenderness of turkey meat. Big 6 breast meat has better tenderness quality and Hybrid XL meat was more profitable because they have heavier part of carcass. Diameter of muscle fiber has strongest factors than others
Current and future technical, economic and environmental feasibility of maize and wheat residues supply for biomass energy application:Illustrated for South Africa
AbstractThis study assessed the feasibility of mobilising maize and wheat residues for large-scale bioenergy applications in South Africa by establishing sustainable residue removal rates and cost of supply based on different production regions. A key objective was to refine the methodology for estimating crop residue harvesting for bioenergy use, while maintaining soil productivity and avoiding displacement of competing residue uses. At current conditions, the sustainable bioenergy potential from maize and wheat residues was estimated to be about 104 PJ. There is potential to increase the amount of crop residues to 238 PJ through measures such as no till cultivation and adopting improved cropping systems. These estimates were based on minimum residues requirements of 2 t ha−1 for soil erosion control and additional residue amounts to maintain 2% SOC level.At the farm gate, crop residues cost between 0.9 and 1.7 GJ−1. In the improved scenario, up to 85% of the biomass is below 1.3 GJ−1 while in the optimised scenario, about 87% is delivered below 5$ GJ−1. Co-firing residues with coal results in lower cost of electricity compared to other renewables and significant GHG (CO2 eq) emissions reduction (up to 0.72 tons MWh−1). Establishing sustainable crop residue supply systems in South Africa could start by utilising the existing agricultural infrastructure to secure supply and develop a functional market. It would then be necessary to incentivise improvements across the value chain
Box traps on an atom chip for one-dimensional quantum gases
We present the implementation of tailored trapping potentials for ultracold
gases on an atom chip. We realize highly elongated traps with box-like
confinement along the long, axial direction combined with conventional harmonic
confinement along the two radial directions. The design, fabrication and
characterization of the atom chip and the box traps is described. We load
ultracold (K) clouds of Rb in a box trap, and demonstrate
Bose-gas focusing as a means to characterize these atomic clouds in arbitrarily
shaped potentials. Our results show that box-like axial potentials on atom
chips are very promising for studies of one-dimensional quantum gases.Comment: 9 pages 4 figure
Continuous selections of multivalued mappings
This survey covers in our opinion the most important results in the theory of
continuous selections of multivalued mappings (approximately) from 2002 through
2012. It extends and continues our previous such survey which appeared in
Recent Progress in General Topology, II, which was published in 2002. In
comparison, our present survey considers more restricted and specific areas of
mathematics. Note that we do not consider the theory of selectors (i.e.
continuous choices of elements from subsets of topological spaces) since this
topics is covered by another survey in this volume
The dynamics and prethermalization of one dimensional quantum systems probed through the full distributions of quantum noise
Quantum noise correlations have been employed in several areas in physics
including condensed matter, quantum optics and ultracold atom to reveal
non-classical states of the systems. So far, such analysis mostly focused on
systems in equilibrium. In this paper, we show that quantum noise is also a
useful tool to characterize and study the non-equilibrium dynamics of one
dimensional system. We consider the Ramsey sequence of one dimensional,
two-component bosons, and obtain simple, analytical expressions of time
evolutions of the full distribution functions for this strongly-correlated,
many-body system. The analysis can also be directly applied to the evolution of
interference patterns between two one dimensional quasi-condensates created
from a single condensate through splitting. Using the tools developed in this
paper, we demonstrate that one dimensional dynamics in these systems exhibits
the phenomenon known as "prethermalization", where the observables of {\it
non-equilibrium}, long-time transient states become indistinguishable from
those of thermal {\it equilibrium} states.Comment: 22 pages, 11 figures+appendi
Precision measurements of the top quark mass from the Tevatron in the pre-LHC era
The top quark is the heaviest of the six quarks of the Standard Model.
Precise knowledge of its mass is important for imposing constraints on a number
of physics processes, including interactions of the as yet unobserved Higgs
boson. The Higgs boson is the only missing particle of the Standard Model,
central to the electroweak symmetry breaking mechanism and generation of
particle masses. In this Review, experimental measurements of the top quark
mass accomplished at the Tevatron, a proton-antiproton collider located at the
Fermi National Accelerator Laboratory, are described. Topologies of top quark
events and methods used to separate signal events from background sources are
discussed. Data analysis techniques used to extract information about the top
mass value are reviewed. The combination of several most precise measurements
performed with the two Tevatron particle detectors, CDF and \D0, yields a value
of \Mt = 173.2 \pm 0.9 GeV/.Comment: This version contains the most up-to-date top quark mass averag
Colour reconnections in Herwig++
We describe the implementation details of the colour reconnection model in
the event generator Herwig++. We study the impact on final-state observables in
detail and confirm the model idea from colour preconfinement on the basis of
studies within the cluster hadronization model. Moreover, we show that the
description of minimum bias and underlying event data at the LHC is improved
with this model and present results of a tune to available data.Comment: 19 pages, 21 figures, 2 tables. Matches with published versio
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