Describing the plastic deformation of aluminium softball bats

Hollow aluminium bats were introduced over 30 years ago to provide improved durability over wooden bats. Since their introduction, however, interest in hollow bats has focused almost exclusively around their hitting performance. The aim of this study was to take advantage of the progress that has been made in predicting bat performance using finite elements and apply it to describe bat durability. Accordingly, the plastic deformation from a ball impact of a single-wall aluminum bat was numerically modelled. The bat deformation from the finite-element analysis was then compared with experiment using a high-speed bat test machine. The ball was modelled as an isotropic, homogeneous, viscoelastic sphere. The viscoelastic parameters of the ball model were found from instrumented, high-speed, rigid-wall ball impacts. The rigid-wall ball impacts were modelled numerically and showed good agreement with the experimentally obtained response. The strain response of the combined bat-ball model was verified with a strain-gauged bat at intermediate ball impact speeds in the elastic range. The strain response of the bat-ball model exhibited positive correlation with the experimental measurements. High-speed bat-ball impacts were performed experimentally and simulated numerically at increasing impact speeds which induced correspondingly increased dent sizes in the bat. The plastic deformation from the numerical model found good agreement with experiment provided the aluminium work hardening and strain rate effects were appropriately described. The inclusion of strain rate effects was shown to have a significant effect on the bat deformations produced in the finite-element simulations. They also helped explain the existence of high bat stresses found in many performance models.     

Restructuring support staff classification levels for academic health sciences library positions

Nonprofessional library support staff traditionally hold what are considered to be low-paying, nonchallenging positions. These negative factors make retaining creative and productive employees difficult. This article outlines the approach taken at the Medical College of Georgia's Robert B. Greenblatt, M.D. Library to devise a structure of library staff positions that becomes progressively more demanding. A new nine-level Library Staff Classification Plan resulted. This plan also enables and encourages employees to acquire more skills and to accept more responsibility in order to qualify for higher-level library positions or to advance their present position to receive comparable rewards. The plan expresses the level of responsibilities expected, the employee qualifications desired, and lists representative duties across the spectrum of typical library tasks.     

The new library building at the University of Texas Health Science Center at San Antonio

The new University of Texas Health Science Center at San Antonio Library opened in June 1983, replacing the 1968 library building. Planning a new library building provides an opportunity for the staff to rethink their philosophy of service. Of paramount concern and importance is the need to convey this philosophy to the architects. This paper describes the planning process and the building's external features, interior layouts, and accommodations for technology. Details of the move to the building are considered and various aspects of the building are reviewed.     

An analysis of the PPCF as a theoretical framework for an instrument to examine teacher priorities for selecting curriculum content

The purpose of the research was to develop an instrument to examine physical education teachers' priorities for curricular decision-making. The purpose dimension of the Purpose Process Curriculum Framework (PPCF) was used as the theoretical structure for content decisions. Three studies are reported that investigate the reliability and validity of the proposed instrument. Items were evaluated for relevance and validity of the proposed instrument. They were evaluated for relevance and theoretical consistency by physical education teachers (Study 1) and curriculum specialists (Study 2). Acceptable items were then placed in a ranking format and field tested with physical educators in three school districts (Study 3). Results from Study 1 indicated that secondary level physical education teachers supported the relevance of items to reflect the educational setting in their classes. In Study 2, mean ratings of curriculum specialists established that 19 of the 22 categories were theoretically consistent with the PPCF. However, internal consistency coefficients (alpha) for 10 of the 22 purposes were less than .70. Follow-up field tests with physical educators in Study 3 indicated that only one category, joy of movement, had a coefficient above .70. In this research internal consistency coefficients were too low to make a claim for the reliability of the concept scales of the instrument. The multidimensionality of the purpose concepts raised questions regarding the validity of the PPCF and prohibited the use of the framework as a theoretical basis for instrument development.