Nucleon-nucleus optical potential in the particle-hole approach

Feshbach's projection formalism in the particle-hole model space leads to a microscopic description of scattering in terms of the many-body self-energy. To investigate the feasibility of this approach, an optical potential for O-16 is constructed starting from two previous calculations of the self-energy for this nucleus. The results reproduce the background phase shifts for positive parity waves and the resonances beyond the mean field. The latter can be computed microscopically for energies of astrophysical interest using Green's function theory.Comment: 8 pages, 6 figures. Submitted to Phys. Rev.

Developing Interventions for Children's Exercise (DICE): a pilot evaluation of school-based exercise interventions for primary school children aged 7 to 8 years.

BACKGROUND: Developing Interventions for Children's Exercise (DICE) is an initiative aimed at determining effective school-based exercise programs. To assess feasibility, we conducted a pilot study of exercise sessions which varied in duration and frequency. METHODS: Exercise interventions were delivered to Year 3 pupils (age 7-8 years; n = 73) in primary schools within Yorkshire, UK. Evaluations were conducted using focus group sessions, questionnaires and observations. RESULTS: The study revealed positive aspects of all interventions, including favorable effects on children's concentration during lessons and identified the value of incorporation of the DICE concept into curriculum lessons. Children appeared enthused and reported well-being and enjoyment. Areas requiring attention were the need for appropriate timetabling of sessions and ensuring the availability of space. CONCLUSION: The concept and sessions were well-accepted by teachers who confirmed their full support of any future implementation There appears to be potential for the encouragement and empowerment of teachers to support physical activity and healthy school environments, and to take an interest in the health of their pupils. Ultimately, these findings should assist in the design of successful exercise interventions in the school setting

Exploring the relationship between stigma and climate related to employee safety and health

This study sought to investigate the relationship between stigma and climate for the strategic priorities of health and safety. Using a two-wave longitudinal design (N = 650), confirmatory factor analysis indicated that stigma is distinct from psychological climate. Additionally, we fit safety and health stigma within the broader conceptual linking mechanisms of their respective climates. The results were somewhat supportive of the hypothesized linking mechanisms of safety stigma but not for health stigma. Lastly, both types of stigma were found to be associated with poorer psychological health

Stockpiling Perennial Warm-Season Grasses: Bermudagrass Example

Winter feeding is the largest expense of maintaining a beef herd in terms of money and time. Stockpiled bermudagrass is an effective practice for reducing winter feeding expenses and extending the grazing season. Stockpiling forage is the practice of accumulating forage growth intended for grazing in a later season. In Arkansas, bermudagrass is stockpiled from early August to late October and is grazed from late October through mid-December. Rainfall during late summer can be erratic with high risk of drought stress, but an early start date maximizes the opportunity for acceptable stockpiled forage yield. Therefore, stockpiling bermudagrass should begin by early August in north Arkansas and by mid-August in south Arkansas to allow enough time for dry matter accumulation before cooler autumn night temperatures slow grass growth. Delaying the initiation of stockpiling from early August until early September reduced forage yield in October by up to 84%. Nitrogen fertilizer should be applied in early August at the N rate of 56-67 kg/ha. Ammonium nitrate or urea are common N sources and studies show that both give similar yield response. Poultry litter or animal manure can also be used as a fertilizer source with good results. Dry matter of stockpiled bermudagrass has been measured up to 6,720 kg/ha in on-farm grazing demonstrations. Forage quality of stockpiled bermudagrass remained above crude protein (CP) and energy (TDN) requirements for nonlactating cows from October through February. Stockpiling bermudagrass is a very reliable practice for extending the grazing season. In ninety on-farm stockpiled forage demonstrations across 32 Arkansas counties, the average savings for stockpiled bermudagrass compared to feeding hay was over $20 per 454-kg animal unit (AU) over the winter hay feeding season

Viable 3C-SiC-on-Si MOSFET design disrupting current Material Technology Limitations

The cubic polytype (3C-) of Silicon Carbide (SiC) is an emerging semiconductor technology for power devices. The featured isotropic material properties along with the Wide Band Gap (WBG) characteristics make it an excellent choice for power Metal Oxide Semiconductor Field Effect Transistors (MOSFETs). Nonetheless, material related limitations originate from the advantageous fact that 3C-SiC can be grown on Silicon (Si) wafers. One of these major limitations is an almost negligible activation of the p-type dopants after ion implantation because the annealing has to take place at relatively low temperatures. In this paper, a novel process flow for a vertical 3C-SiC-on-Si MOSFET is presented to overcome the difficulties that currently exist in obtaining a p-body region through implantation. The proposed design has been accurately simulated with Technology Computer Aided Design (TCAD) process and device software and a comparison is performed with the conventional SiC MOSFET design. The simulated output characteristics demonstrated a reduced on-resistance and at the same time it is shown that the blocking capability can be maintained to the same level. The promising performance of the novel design discussed in this paper is potentially the solution needed and a huge step towards the realisation of 3C-SiC-on-Si MOSFETs with commercially grated characteristics

Sum Rule Description of Color Transparency

The assumption that a small point-like configuration does not interact with nucleons leads to a new set of sum rules that are interpreted as models of the baryon-nucleon interaction. These models are rendered semi-realistic by requiring consistency with data for cross section fluctuations in proton-proton diffractive collisions.Comment: 22 pages + 3 postscript figures attache

Multiple-Scattering Series For Color Transparency

Color transparency CT depends on the formation of a wavepacket of small spatial extent. It is useful to interpret experimental searches for CT with a multiple scattering scattering series based on wavepacket-nucleon scattering instead of the standard one using nucleon-nucleon scattering. We develop several new techniques which are valid for differing ranges of energy. These techniques are applied to verify some early approximations; study new forms of the wave-packet-nucleon interaction; examine effects of treating wave packets of non-zero size; and predict the production of $N^*$'s in electron scattering experiments.Comment: 26 pages, U.Wa. preprint 40427-23-N9

Quark-Meson Coupling Model for a Nucleon

The quark-meson coupling model for a nucleon is considered. The model describes a nucleon as an MIT bag, in which quarks are coupled to scalar and vector mesons. A set of coupled equations for the quark and the meson fields are obtained and are solved in a self-consistent way. It is shown that the mass of a nucleon as a dressed MIT bag interacting with sigma- and omega-meson fields significantly differs from the mass of a free MIT bag. A few sets of model parameters are obtained so that the mass of a dressed MIT bag becomes the nucleon mass. The results of our calculations imply that the self-energy of the bag in the quark-meson coupling model is significant and needs to be considered in doing the nuclear matter calculations.Comment: 3 figure