A Fast Serial Algorithm for the Finite Temperature Quenched Potts Model

An efficient serial algorithm for finite temperature, quenched Potts model simulations of domain evolution has been developed. This \u27\u27n‐fold way\u27\u27 algorithm eliminates unsuccessful spin flip attempts a priori by flipping sites with a frequency proportional to their site activity, defined as the sum of the probability of success for every possible spin flip at that site. Finite temperature efficiency for high‐spin degeneracy systems is achieved by utilizing a new, analytical expression for the portion of the site activity due to flips to non-neighbor spin values. Hence, to determine the activity of a site, only flips to the nearest neighbor spin values need be considered individually; all other flips are evaluated in a single expression. A complexity analysis of this algorithm gives the dependence of computing time on system parameters and on simulation progress. While a conventional Potts model algorithm has a constant computing time per simulation timestep, the n-fold way algorithm increases in efficiency as domain coarsening progresses. Computer experiments confirm the complexity analysis results and indicate that the n-fold way algorithm is much more efficient than the conventional algorithm even at high fractions of the critical temperature

A Simple Electric Field Probe in a Gauss\u27s Law Laboratory

Early in our calculus-based introductory course, students are introduced to electric fields and sometimes struggle with the abstraction of a vector field. They have less familiarity with the phenomena associated with electric fields, and the connection between phenomena and mathematical formalism is weaker. Our very next topic is Gauss\u27s law

Supporting an Introductory EM Lab Redesign with the E-CLASS and AAPT Lab Guidelines

This poster presents the preliminary results of attitude surveys (E-CLASS - U. Colorado) given to students taking the current PHYS-225 - Electricity & Magnetism Laboratory at Kettering University as well as the beginnings of work done in redesigning the course around a set of skills-based learning outcomes and design activities to progress students toward achieving these goals. These outcomes will encourage students to: ask and answer scientific questions through experimental design and implementation; develop technical and practical laboratory skills; generate, analyze, and interpret data; incorporate uncertainty in measured values, calculated values, and graphical representations; and write effective technical reports that articulate the reasoning that connects theoretical models to laboratory activities and use appropriate style and voice. Our goals are to produce a more authentic laboratory experience through the use of open-ended activities, building reflection into assignments, and allowing students to have more of a say in what they are investigating. *The presenters would like to thank the authors of the E-CLASS surve

Effects of particle size on inhibited grain growth

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28802/1/0000636.pd

Pch2 Links Chromosome Axis Remodeling at Future Crossover Sites and Crossover Distribution during Yeast Meiosis

Segregation of homologous chromosomes during meiosis I depends on appropriately positioned crossovers/chiasmata. Crossover assurance ensures at least one crossover per homolog pair, while interference reduces double crossovers. Here, we have investigated the interplay between chromosome axis morphogenesis and non-random crossover placement. We demonstrate that chromosome axes are structurally modified at future crossover sites as indicated by correspondence between crossover designation marker Zip3 and domains enriched for axis ensemble Hop1/Red1. This association is first detected at the zygotene stage, persists until double Holliday junction resolution, and is controlled by the conserved AAA+ ATPase Pch2. Pch2 further mediates crossover interference, although it is dispensable for crossover formation at normal levels. Thus, interference appears to be superimposed on underlying mechanisms of crossover formation. When recombination-initiating DSBs are reduced, Pch2 is also required for viable spore formation, consistent with further functions in chiasma formation. pch2Δ mutant defects in crossover interference and spore viability at reduced DSB levels are oppositely modulated by temperature, suggesting contributions of two separable pathways to crossover control. Roles of Pch2 in controlling both chromosome axis morphogenesis and crossover placement suggest linkage between these processes. Pch2 is proposed to reorganize chromosome axes into a tiling array of long-range crossover control modules, resulting in chiasma formation at minimum levels and with maximum spacing

The pch2Δ Mutation in Baker's Yeast Alters Meiotic Crossover Levels and Confers a Defect in Crossover Interference

Pch2 is a widely conserved protein that is required in baker's yeast for the organization of meiotic chromosome axes into specific domains. We provide four lines of evidence suggesting that it regulates the formation and distribution of crossover events required to promote chromosome segregation at Meiosis I. First, pch2Δ mutants display wild-type crossover levels on a small (III) chromosome, but increased levels on larger (VII, VIII, XV) chromosomes. Second, pch2Δ mutants show defects in crossover interference. Third, crossovers observed in pch2Δ require both Msh4-Msh5 and Mms4-Mus81 functions. Lastly, the pch2Δ mutation decreases spore viability and disrupts crossover interference in spo11 hypomorph strains that have reduced levels of meiosis-induced double-strand breaks. Based on these and previous observations, we propose a model in which Pch2 functions at an early step in crossover control to ensure that every homolog pair receives an obligate crossover

Faculty Senate reorganization: Bylaw Changes

In response to the Faculty Senate’s charge, we present for your consideration three separate proposals dealing with restructuring of the Kettering University faculty governance system. This is Part Two: Bylaw Revisions. In this part, we propose changes to the Faculty Senate Bylaws. Such changes must be approved by both a two-thirds majority of those voting (with notice) at a Faculty Senate meeting. These changes do not require a Faculty-wide vote. The proposed changes contained in this proposal accomplish the following tasks: Defining the manner in which members of Representative Faculty and General Faculty Committees are elected. Removing the definitions of all old Senate committees. Removing the definition of ad-hoc Senate committees, while retaining the definition of task forces. (The distinction between the two forms seems minor; one should suffice.) Creating a section for the definition of new Senate committees (of both forms). Correcting other minor errors

Computer Simulation of Grain Growth with Mobile Particles

[From the Introduction] The microstructures of metallic and ceramic materials are known to be strongly influenced by the presence of second phase particles. Second phase particles may pin grain boundaries and hence may be used to limit grain size (l-4). When particles are mobile, grain boundary/particle interactions typically lead to an even higher density of grain boundary/particle intersections than with static particles. The present paper addresses the influence of mobile particles on grain size evolution in polycrystalline materials. Particle mobility varies sensitively with particle size r (as l/r3 or l/r4) and temperature (in an Arrhenius manner) (5,6). Thus the effects of non-zero particle mobility on gram structure should be most easily observed at elevated temperatures and for small particles. Interactions between moving gram boundaries and mobile impurities has received considerable attention (e.g., (7-9)). These studies have shown that when the driving force on the gram boundary is small (or the impurity mobility is large), impurities diffuse to the moving boundary, and the boundary impurities move together, in a highly correlated manner. In this case, the boundary velocity will be small. But if the driving force on the boundary is large, or the impurity mobility is low, the boundary can escape the impurities and move at a much higher velocity In some cases, these two regimes are not easily distinguished. In the present study, we employ a Monte Carlo simulation procedure to study grain growth in the presence of diffusing particles. This simulation procedure has been used to study a wide variety of grain growth phenomena (2-4,10-13). We examine the temporal evolution of the grain size and microstructure, and the influence of particle fraction, and temperature. The results are analyzed in terms of the relationship between the boundary driving force and the steady state boundary velocity

Faculty Senate Reorganization: Committee Changes

In response to the Faculty Senate’s charge, we present for your consideration three separate proposals dealing with restructuring of theKetteringUniversityfaculty governance system. This is Part Three: Committee Revisions. In this part, we propose changes to the Faculty Senate Bylaws. Such changes must be approved by both a two-thirds majority of those voting (with notice) at a Faculty Senate meeting. These changes do not require a Faculty-wide vote. On the following pages, we propose the creation of eight Senate committees: Curriculum (Representative Faculty) Promotion, Tenure, and Ethics (Representative Faculty) Policy Review (General Faculty) International Programs (General Faculty) Senior Thesis (General Faculty) Recruitment and Retention (General Faculty) Academic Computing (General Faculty) Resources (General Faculty