54,521 research outputs found

    Classical Hadrodynamics: A New Approach to Ultrarelativistic Heavy-Ion Collisions

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    We discuss a new approach to ultrarelativistic heavy-ion collisions based on classical hadrodynamics for extended nucleons, corresponding to nucleons of finite size interacting with massive meson fields. This new theory provides a natural covariant microscopic approach that includes automatically spacetime nonlocality and retardation, nonequilibrium phenomena, interactions among all nucleons and particle production. In the current version of our theory, we consider NN extended unexcited nucleons interacting with massive neutral scalar (σ\sigma) and neutral vector (ω\omega) meson fields. The resulting classical relativistic many-body equations of motion are solved numerically without further approximation for soft nucleon-nucleon collisions at plabp_{\rm lab} = 14.6, 30, 60, 100 and 200 GeV/cc to yield the transverse momentum imparted to the nucleons. For the future development of the theory, the isovector pseudoscalar (π+\pi^+, π\pi^-, π0\pi^0), isovector scalar (δ+\delta^+, δ\delta^-, δ0\delta^0), isovector vector (ρ+\rho^+, ρ\rho^-, ρ0\rho^0) and neutral pseudoscalar (η\eta) meson fields that are known to be important from nucleon-nucleon scattering experiments should be incorporated. In addition, the effects of quantum uncertainty on the equations of motion should be included by use of techniques analogous to those used by Moniz and Sharp for nonrelativistic quantum electrodynamics.Comment: 6 pages, LA-UR-94-217

    Barriers to Youth Connections to Work: The Case of Young People in the Low-Income Neighborhood of Caju in Rio de Janeiro

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    This paper takes advantage of an unusually detailed family and youth survey conducted by the Institute for the Study of Work and Society (IETS) in Rio de Janeiro in the low-income community of Caju close to downtown Rio. It describes the weak educational background of Caju youth and some of the reasons for that weakness. The results emphasize the precarious nature of low-income youth's educational achievements and their attachment to the job market. They also demonstrate the wide variance in youth characteristics even in a single low-income neighborhood

    FOTE 2008 Conference Report

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    A report prepared by JA.Net and ULCC about the Future of Technology in Education (FOTE 2008) conference, Imperial College, 3rd October 2008. It covers the main speakers, themes and presentations: Cloud Computing, Second Life, Portability, Personalisation, Shared Services, Campus of the Future, Mobile Technology, Creativity and Media Production, Social Collaboration Tools for Staff and Students

    Transcript of The Boat Inspection

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    This story is an excerpt from a longer interview that was collected as part of the Launching through the Surf: The Dory Fleet of Pacific City project. In this story, Nancy Bush recounts a humorous story about a boat inspection by the Coast Guard

    Educational leadership and management : theory, policy, and practice

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    There is great interest in educational leadership in the early part of the 21st century because of the widespread belief that the quality of leadership makes a significant difference to school and student outcomes. There is also increasing recognition that schools require effective leaders and managers if they are to provide the best po ssible education for their learners. Schools need trained and committed teachers but they, in turn, need the leadership of highly effective principals and support from other senior and middle managers. While the need for eff ective lead ers is widely acknowledged, there is much less certainty about which leadership behaviours are most likely to produce favourable outcomes. I examine the theoretic al underpinnings for the fie ld of educational leadership and management, assess different leadership models, and discuss the evidence of their relative effectiveness in developing successfu l schools

    Contextualising fisheries policy in the Lower Mekong Basin

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    Development policies for fishery resources within the Mekong River Basin are increasingly divided between aquaculture and capture fisheries. The modern production orientation of aquaculture has been adopted by government and NGOs and justified by the rhetoric of poverty alleviation and rural development. In contrast, capture fisheries has been subjugated as an activity that reaffirms the dependency of the rural poor on natural resources. This paper critically analyses the division between aquaculture and capture fisheries in Cambodia, Thailand and Lao PDR by tracing the emergence and influence of `development narratives¿ used to justify contemporary policy and practice

    Does macronutrient consumption affect aerobic capacity?

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    Background: Fitness in the United States is declining as the prevalence of obesity rises. It is known generally that exercise and diet both play a part in becoming fit, therefore veering away from being obese and/or overweight. Although people are aware they need to eat healthy foods and participate in physical activity, the role that dietary behaviors have on exercise, particularly aerobic capacity, remains unresolved. Purpose: The purpose of this study was to analyze dietary behaviors and to examine associations with maximal aerobic capacity. We hypothesize that those who consume each food group will have a higher volume of oxygen uptake. Methodology: This cross-sectional study consisted of a convenience sample of students, faculty, and staff (at least 18 years and older) that visited the Exercise Science Research Center as part of the larger Exercise is Medicine project. Participants completed a treadmill maximal oxygen uptake test to determine their VO2 max and were administered a 24-hour diet recall. In addition, they completed an online survey on dietary behaviors. Preliminary analyses examined associations between dietary patterns from the online survey and aerobic capacity. Linear regressions were used to test the associations between dietary behaviors (independent variable) and aerobic capacity (dependent variable) and were adjusted for sex and age. Results: There were a total of 47 participants (n=29 women) to date who have participated, with a mean age of 29.2 (SD 12.5, range 19.1 to 66.0). The average aerobic capacity of women was 36.6 ml/kg/min (SD 8.0), ranging from 15.2 to 51.8. The average aerobic capacity of men was 43.4 ml/kg/min (SD 6.8), ranging from 33.1 to 55.1. Aerobic capacity did not differ between those who drank milk daily vs those who did not (β -2.7, p=.350), those who ate fruit daily (β -.06, p=.798), ate whole grains at least 3 times per week (-2.9, p=.257), ate red meat at least 3 days per week (β -0.4, p=.844), or those who never ate dessert (β -7.1, p=.098). Discussion: There were no significant differences in VO2 max scores between those who consumed milk, fruit, whole grains, red meat, and dessert versus those that did not. This is likely because aerobic capacity is altered from performing exercise, rather than eating certain food groups. Although dietary behaviors are not associated with aerobic capacity, the evaluation of macronutrients compared to aerobic capacity will be examined as a part of this study. In the future, studies should include an analysis of both energy consumption and exercise participation to improve health and fitness outcomes

    Tunnel-diode circuit features zero-level clipping

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    Tunnel-diode circuit starts clipping action as input voltage crosses zero axis. This clipper circuit is effective as limiter in FM receiver
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