956 research outputs found
Molecular vibration in cold collision theory
Cold collisions of ground state oxygen molecules with Helium have been
investigated in a wide range of cold collision energies (from 1 K up to 10
K) treating the oxygen molecule first as a rigid rotor and then introducing the
vibrational degree of freedom. The comparison between the two models shows that
at low energies the rigid rotor approximation is very accurate and able to
describe all the dynamical features of the system. The comparison between the
two models has also been extended to cases where the interaction potential He -
O is made artificially stronger. In this case vibration can perturb rate
constants, but fine-tuning the rigid rotor potential can alleviate the
discrepancies between the two models.Comment: 11 pages, 3 figure
Meissner state in finite superconducting cylinders with uniform applied magnetic field
We study the magnetic response of superconductors in the presence of low
values of a uniform applied magnetic field. We report measurements of DC
magnetization and AC magnetic susceptibility performed on niobium cylinders of
different length-to-radius ratios, which show a dramatic enhance of the initial
magnetization for thin samples, due to the demagnetizing effects. The
experimental results are analyzed by applying a model that calculates the
magnetic response of the superconductor, taking into account the effects of the
demagnetizing fields. We use the results of magnetization and current and field
distributions of perfectly diamagnetic cylinders to discuss the physics of the
demagnetizing effects in the Meissner state of type-II superconductors.Comment: Accepted to be published in Phys. Rev. B; 15 pages, 7 ps figure
A Global Review of Innovative Practices in Regional SME Exporting Strategies and Foreign Direct Investment Attraction
This Co-Learning Plan describes findings from the MSU Center for Community and Economic Development based on research conducted at a global scale to identify innovative practices in regional exporting strategies and foreign direct investment (FDI) attraction
Direct visualization of coexisting channels of interaction in CeSb
Our understanding of correlated electron systems is vexed by the complexity of their interactions. Heavy fermion compounds are archetypal examples of this physics, leading to exotic properties that weave magnetism, superconductivity and strange metal behavior together. The Kondo semimetal CeSb is an unusual example where different channels of interaction not only coexist, but have coincident physical signatures, leading to decades of debate about the microscopic picture describing the interactions between the f moments and the itinerant electron sea. Using angle-resolved photoemission spectroscopy, we resonantly enhance the response of the Ce f electrons across the magnetic transitions of CeSb and find there are two distinct modes of interaction that are simultaneously active, but on different kinds of carriers. This study reveals how correlated systems can reconcile the coexistence of different modes on interaction-by separating their action in momentum space, they allow their coexistence in real space.11Ysciescopu
The status of sow welfare in selected districts of Uganda
Objective
The pig sector in Uganda is among the fastest growing livestock sectors and is characterized by low
productivity from limited resources and veterinary support. As the welfare status of pigs in the
system is unknown a cross-sectional welfare assessment was carried out in four districts in central
Uganda (Masaka, Mukono, Mpigi and Wakiso) to identify issues requiring action.
Materials and methods
Data were collected from 270 pig farms. Data on animal-based indicators (body condition and
physical injuries) and resource-based indicators (housing and water supply) were obtained from
physical assessments of pigs and farm facilities. Management data (morbidity and mortality) and
demographic details were collected from farmer interview. We present sow results as they are the
highest value animal of the herd, both raising piglets and requiring resource investment.
Results
Across all farms, sow mortality was 2.5%. Animal-based indicators identified 9% of sows with
diarrhea, 7.6% with lameness and 92% dry or lactating were found to be āskinnyā (body condition
scoreā¤2). All of these are indicative of underperforming sows that may be at risk of low litter indices
and shorter productive lives. Sow behaviour was restricted in 19% of cases, and while 93% of sows
had access to continuous water, only 48.8% received clean water, which creates a risk of disease
spread. Of reported health issues, 20% farms reported sows experiencing stillbirths, 15% ill thrift,
12.5% respiratory issues and 10.8% gastrointestinal issues.
Conclusion
These welfare issues indicates that a proportion of sows were in pain, discomfort and potentially
hungry, which in turn negatively impact on owner livelihoods from wasted resources and
opportunities. Future interventions focusing on herd health should focus on diseases and poor
nutrition. Interventions that provide access to clean water and optimum living space that give sows
the ability to move more freely are also required
Superfluid pairing in a polarized dipolar Fermi gas
We calculate the critical temperature of a superfluid phase transition in a
polarized Fermi gas of dipolar particles. In this case the order parameter is
anisotropic and has a nontrivial energy dependence. Cooper pairs do not have a
definite value of the angular momentum and are coherent superpositions of all
odd angular momenta. Our results describe prospects for achieving the
superfluid transition in single-component gases of fermionic polar molecules.Comment: 12 pages, 2 figure
The deep propagating gravity wave experiment (deepwave): an airborne and ground-based exploration of gravity wave propagation and effects from their sources throughout the lower and middle atmosphere
Abstract
The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic and other sources to regions of dissipation at high altitudes. The core DEEPWAVE field phase took place from May through July 2014 using a comprehensive suite of airborne and ground-based instruments providing measurements from Earthās surface to ā¼100 km. Austral winter was chosen to observe deep GW propagation to high altitudes. DEEPWAVE was based on South Island, New Zealand, to provide access to the New Zealand and Tasmanian āhotspotsā of GW activity and additional GW sources over the Southern Ocean and Tasman Sea. To observe GWs up to ā¼100 km, DEEPWAVE utilized three new instruments built specifically for the National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) Gulfstream V (GV): a Rayleigh lidar, a sodium resonance lidar, and an advanced mesosphere temperature mapper. These measurements were supplemented by in situ probes, dropsondes, and a microwave temperature profiler on the GV and by in situ probes and a Doppler lidar aboard the German DLR Falcon. Extensive ground-based instrumentation and radiosondes were deployed on South Island, Tasmania, and Southern Ocean islands. Deep orographic GWs were a primary target but multiple flights also observed deep GWs arising from deep convection, jet streams, and frontal systems. Highlights include the following: 1) strong orographic GW forcing accompanying strong cross-mountain flows, 2) strong high-altitude responses even when orographic forcing was weak, 3) large-scale GWs at high altitudes arising from jet stream sources, and 4) significant flight-level energy fluxes and often very large momentum fluxes at high altitudes.David C. Fritts, Ronald B. Smith, Michael J. Taylor, James D. Doyle, Stephen D. Eckermann, Andreas Dƶrnbrack, Markus Rapp, Bifffford P. Williams, P.-Dominique Pautet, Katrina Bossert, Neal R. Criddddle, Carolyn A. Reynolds, P. Alex Reinecke, Michael Uddddstrom, Michael J. Revell, Richard Turner, Bernd Kaifler, Johannes S. Wagner, Tyler Mixa, Christopher G. Kruse, Alison D. Nugent, Campbell D. Watson, Sonja Gisinger, Steven M. Smith, Ruth S. Lieberman, Brian Laughman, James J. Moore, William O. Brown, Julie A. Haggerty, Alison Rockwell, Gregory J. Stossmeister, Steven F. Williams, Gonzalo Hernandez, Damian J. Murphy, Andrew R. Klekociuk, Iain M. Reid, and Jun M
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