2,840 research outputs found
Macroscopic-Microscopic Mass Models
We discuss recent developments in macroscopic-microscopic mass models,
including the 1992 finite-range droplet model, the 1992 extended-Thomas-Fermi
Strutinsky-integral model, and the 1994 Thomas-Fermi model, with particular
emphasis on how well they extrapolate to new regions of nuclei. We also address
what recent developments in macroscopic-microscopic mass models are teaching us
about such physically relevant issues as the nuclear curvature energy, a new
congruence energy arising from a greater-than-average overlap of neutron and
proton wave functions, the nuclear incompressibility coefficient, and the
Coulomb redistribution energy arising from a central density depression. We
conclude with a brief discussion of the recently discovered rock of metastable
superheavy nuclei near 272:110 that had been correctly predicted by
macroscopic-microscopic models, along with a possible new tack for reaching an
island near 290:110 beyond our present horizon.Comment: 10 pages. LaTeX. Presented at International Conference on Exotic
Nuclei and Atomic Masses (ENAM 95), Arles, France, June 19-23, 1995. To be
published in conference proceedings by Les Editions Frontieres, Gif sur
Yvette, France. Seven figures not included here. PostScript version with
figures available at http://t2.lanl.gov/pub/publications/publications.html or
by anonymous ftp at ftp://t2.lanl.gov/pub/publications/enam9
Fluid dynamical description of relativistic nuclear collisions
On the basis of both a conventional relativistic nuclear fluid dynamic model and a two fluid generalization that takes into account the interpenetration of the target and projectile upon contact, collisions between heavy nuclei moving at relativistic speeds are calculated. This is done by solving the relevant equations of motion numerically in three spatial dimensions by use of particle in cell finite difference computing techniques. The effect of incorporating a density isomer, or quasistable state, in the nuclear equation of state at three times normal nuclear density, and the effect of doubling the nuclear compressibility coefficient are studied. For the reaction 20Ne + 238U at a laboratory bombarding energy per nucleon of 393 MeV, the calculated distributions in energy and angle of outgoing charged particles are compared with recent experimental data both integrated over all impact parameters and for nearly central collisions
Impacts on Teacher Evaluations: The Importance of Building Capacity through Excellence in the Application of the Teacher Evaluation Process
Significant student learning and school improvement are dependent upon the teacher being the centerpiece (Tucker, Stronge, Gareis, & Beers, 2003; National Council of Teacher Quality, 2011). In maintaining the high standards associated with teaching responsibilities, educators are held accountable through performance evaluations. In the United States, teacher evaluations have long been a standard of practice largely determined by individual states and school districts. Additionally, teacher effectiveness has been guided by at least three pieces of national legislation, including the Elementary and Secondary Education Act (ESEA, 1965), the No Child Left Behind Act (NCLB, 2001) and the American Recovery and Reinvestment Act (ARRA, 2009), also referred to as the Stimulus or Recovery Act. With the expectation that the nation\u27s universities produce higher quality teachers and school districts hire highly qualified teachers, the profession finds itself under constant, critical scrutiny, most recently concerning the evaluation of teachers
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