American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA
Jean Moon, Ph.D.
Advisor to the ExxonMobil Foundation’s Education Programs, 321 Reedy Meadow Road, Groton, Massachusetts 01450 USA
W. Even and M.W. Roth
Department of Physics, University of Northern Iowa, Cedar Falls, IA 50614-0150 USA
New deterministic computer simulations have been developed for studying the dynamics of large objects colliding. For various initial conditions the system may clump together forming a new object or may rotate, causing ejecta to leave the primary mass in a pattern sustaining only a short number of orbits, but promising of satellite formation. Bodies without a large central mass are not able to form a cohesive object, and fly apart upon impact. A rudimentary scaling study when the code is parallelized using a force-decomposition scheme suggests that the computational time scales inversely as the number of processors when less than four are involved and the gains are somewhat less pronounced as the number of processors increases.
Authors and Affiliations:
Megan Apperson, Heather Schmidt, Sarah Moore, and Leon Grunberg
Comparative Sociology Department, University of Puget Sound, Tacoma, Washington 98416 USA
Department of Political Science, University of Colorado, Boulder, Colorado 80309-0483 USA
Gender and managerial status have previously been found to relate to work-family conflict, though the combination of gender and managerial status has received less attention. This study explores differences in levels of work-family conflict and related job attitude and health and coping variables among women managers, men managers, women non-managers, and men non-managers at a large organization. Women managers experienced higher levels of work-family conflict, work role overload, and problem drinking. However, the levels of work to family conflict were unexpectedly similar between women and men managers. Possible explanations for this are considered.
Abnita Munankarmy and Michael A. Heroux
Department of Computer Science, College of Saint Benedict, 37 South College Avenue, St. Joseph, Minnesota 56374 USA
Many iterative linear solver packages focus on real-valued systems and do not deal well with complex-valued systems, even though preconditioned iterative methods typically apply to both real and complex-valued linear systems. Instead, commonly available packages such as PETSc  and Aztec  tend to focus on the real-valued systems, while complex-valued systems are seen as a late addition. At the same time, by changing the complex problem into an equivalent real formulation (ERF), a real valued solver can be used. In this paper we consider two ERF’s that can be used to solve complex-valued linear systems. We investigate the spectral properties of each and show how each can be preconditioned to move eigenvalues in a cloud around the point (1,0) in the complex plane. Finally, we consider an interleaved formulation, combining each of the previously mentioned approaches, and show that the interleaved form achieves a better outcome than either separate ERF.
Authors and Affiliations:
C. Stark and P.M. Shand
Physics Department, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA
Department of Chemistry and Physics, University of North Florida, Jacksonville, Florida 32224 USA
D. Williams, R. Brown, L. Yue, and D.L. Leslie-Pelecky
Center for Materials Research and Analysis, and Department of Physics & Astronomy, University of Nebraska, Lincoln, Nebraska 68588-0111 USA
Measurements of DC susceptibility, AC susceptibility, and AC susceptibility with an applied DC bias field were performed on mechanically milled GdAl2. A paramagnetic phase exists above a temperature T ≈ 140 K. However, there are significant deviations from the Curie-Weiss Law in this temperature regime, suggesting multiple magnetic components. Fits to the high temperature data show that two Curie-Weiss terms represent the data quite well. Below 140 K one of these magnetic components becomes ferromagnetic as indicated by a shoulder in the AC susceptibility and DC susceptibility data. This ferromagnetic component is suppressed by the application of sufficiently strong DC bias field. Accompanying this shoulder is a peak at lower temperatures (T < 50 K), which suggests the existence of another component that is magnetically glassy in nature. The two-component behavior of mechanically milled GdAl2 can be explained in terms of the nanostructure of the material, which consists of nanometer-sized grains and a disordered interphase.