2,119 research outputs found
Final excitation energy of fission fragments
We study how the excitation energy of the fully accelerated fission fragments
is built up. It is stressed that only the intrinsic excitation energy available
before scission can be exchanged between the fission fragments to achieve
thermal equilibrium. This is in contradiction with most models used to
calculate prompt neutron emission where it is assumed that the total excitation
energy of the final fragments is shared between the fragments by the condition
of equal temperatures. We also study the intrinsic excitation-energy partition
according to a level density description with a transition from a
constant-temperature regime to a Fermi-gas regime. Complete or partial
excitation-energy sorting is found at energies well above the transition
energy.Comment: 8 pages, 3 figure
Thermodynamics of nuclei in thermal contact
The behaviour of a di-nuclear system in the regime of strong pairing
correlations is studied with the methods of statistical mechanics. It is shown
that the thermal averaging is strong enough to assure the application of
thermodynamical methods to the energy exchange between the two nuclei in
contact. In particular, thermal averaging justifies the definition of a nuclear
temperature.Comment: 9 pages, 1 figur
Chiminey: Reliable Computing and Data Management Platform in the Cloud
The enabling of scientific experiments that are embarrassingly parallel, long
running and data-intensive into a cloud-based execution environment is a
desirable, though complex undertaking for many researchers. The management of
such virtual environments is cumbersome and not necessarily within the core
skill set for scientists and engineers. We present here Chiminey, a software
platform that enables researchers to (i) run applications on both traditional
high-performance computing and cloud-based computing infrastructures, (ii)
handle failure during execution, (iii) curate and visualise execution outputs,
(iv) share such data with collaborators or the public, and (v) search for
publicly available data.Comment: Preprint, ICSE 201
PROUD: Effects of preoperative long-term immunonutrition in patients listed for liver transplantation
<p>Abstract</p> <p>Background</p> <p>Patients with end stage liver disease are characteristically malnourished which is associated with poor outcome. Formulas enriched with arginine, ω-3 fatty acids, and nucleotides, "immunonutrients", potentially improve their nutritional status. This study is designed to evaluate the clinical outcome of long-term "immunonutrition" of patients with end-stage liver disease while on the waiting list for liver transplantation.</p> <p>Methods/design</p> <p>A randomized controlled double blind multi-center clinical trial with two parallel groups comprising a total of 142 newly registered patients for primary liver transplantation has been designed to assess the safety and efficacy of the long-term administration of ORAL IMPACT<sup>®</sup>, an "immunonutrient" formula, while waiting for a graft. Patients will be enrolled the day of registration on the waiting list for liver transplantation. Study ends on the day of transplantation. Primary endpoints include improved patients' nutritional and physiological status, as measured by mid-arm muscle area, triceps skin fold thickness, grip strength, and fatigue score, as well as patients' health related quality of life. Furthermore, patients will be followed for 12 postoperative weeks to evaluate anabolic recovery after transplantation as shown by reduced post-transplant mechanical ventilation, hospital stay, wound healing, infectious morbidities (pneumonia, intraabdominal abscess, sepsis, line sepsis, wound infection, and urinary tract infection), acute and chronic rejection, and mortality.</p> <p>Discussion</p> <p>Formulas enriched with arginine, ω-3 fatty acids, and nucleotides have been proven to be beneficial in reducing postoperative infectious complications and length of hospital stay among the patients undergoing elective gastrointestinal surgery. Possible mechanisms include downregulation of the inflammatory responses to surgery and immune modulation rather than a sole nutritional effect.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00495859</p
Heisenberg exchange parameters of molecular magnets from the high-temperature susceptibility expansion
We provide exact analytical expressions for the magnetic susceptibility
function in the high temperature expansion for finite Heisenberg spin systems
with an arbitrary coupling matrix, arbitrary single-spin quantum number, and
arbitrary number of spins. The results can be used to determine unknown
exchange parameters from zero-field magnetic susceptibility measurements
without diagonalizing the system Hamiltonian. We demonstrate the possibility of
reconstructing the exchange parameters from simulated data for two specific
model systems. We examine the accuracy and stability of the proposed method.Comment: 13 pages, 7 figures, submitted to Phys. Rev.
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