1,545 research outputs found
Analytic Criteria for Power Exhaust in Divertors due to Impurity Radiation
Present divertor concepts for next step experiments such ITER and TPX rely
upon impurity and hydrogen radiation to transfer the energy from the edge
plasma to the main chamber and divertor chamber walls. The efficiency of these
processes depends strongly on the heat flux, the impurity species, and the
connection length. Using a database for impurity radiation rates constructed
from the ADPAK code package, we have developed criteria for the required
impurity fraction, impurity species, connection length and electron temperature
and density at the mid-plane. Consistent with previous work, we find that the
impurity radiation from coronal equilibrium rates is, in general, not adequate
to exhaust the highest expected heating powers in present and future
experiments. As suggested by others, we examine the effects of enhancing the
radiation rates with charge exchange recombination and impurity recycling, and
develop criteria for the minimum neutral fraction and impurity recycling rate
that is required to exhaust a specified power. We also use this criteria to
find the optimum impurity for divertor power exhaust.Comment: Preprint for the 11th PSI meeting, Adobe pdf with 14 figures, 15
page
PCN46 HEALTH CARE EXPENDITURES, DISABILITY DAYS, AND RESOURCE UTILIZATION ASSOCIATED WITH CANCER IN EMPLOYER SETTINGS IN THE UNITED STATES
Role of zonal flows in TEM turbulence through nonlinear gyrokinetic particle and continuum simulation
Role of zonal flows in trapped electron mode turbulence through nonlinear gyrokinetic particle and continuum simulation
Platelet-derived growth factor applications in periodontal and peri-implant bone regeneration
Introduction: Achieving successful tissue regeneration following traditional therapeutic protocols, combining bone grafts and barrier membranes, may be challenging in certain clinical scenarios. A deeper understanding of periodontal and peri-implant wound healing and recent advances in the field of tissue engineering have provided clinicians with novel means to obtain predictable clinical outcomes. The use of growth factors such as recombinant
human platelet-derived growth factor-BB (rhPDGF) with biocompatible matrices to promote tissue regeneration represents a promising approach in the disciplines of periodontology and implantology.
Areas covered: This review covers the basic principles of bone and periodontal regeneration, and provides an overview of the biology of PDGF and its potential to predictably and reproducibly promote bone regeneration in regular clinical practice. The results of preclinical and clinical human studies evaluating the effectiveness of growth-factor-enhanced matrices are analyzed and discussed.
Expert opinion: Current available evidence supports the use of rhPDGF-enhanced matrices to promote periodontal and peri-implant bone regeneration
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