Administrative automation in a scientific environment

Although the scientific personnel at GSFC were advanced in the development and use of hardware and software for scientific applications, resistance to the use of automation or purchase of terminals, software and services, specifically for administrative functions was widespread. The approach used to address problems and constraints and plans for administrative automation within the Space and Earth Sciences Directorate are delineated. Accomplishments thus far include reduction of paperwork and manual efforts; improved communications through telemail and committees; additional support staff; increased awareness at all levels on ergonomic concerns and the need for training; better equipment; improved ADP skills through experience; management commitment; and an overall strategy for automating

Effects of cobalt in nickel-base superalloys

The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys

Recalibrating the Wide-field Infrared Survey Explorer (WISE) W4 Filter

We present a revised effective wavelength and photometric calibration for the Wide-field Infrared Survey Explorer (WISE) W4 band, including tests of empirically motivated modifications to its pre-launch laboratory-measured relative system response curve. We derived these by comparing measured W4 photometry with photometry synthesised from spectra of galaxies and planetary nebulae. The difference between measured and synthesised photometry using the pre-launch laboratory-measured W4 relative system response can be as large as 0.3 mag for galaxies and 1 mag for planetary nebulae. We find the W4 effective wavelength should be revised upward by 3.3%, from 22.1 micron to 22.8 micron, and the W4 AB magnitude of Vega should be revised from m = 6.59 to m = 6.66. In an attempt to reproduce the observed W4 photometry, we tested three modifications to the pre-launch laboratory-measured W4 relative system response curve, all of which have an effective wavelength of 22.8 micron. Of the three relative system response curve models tested, a model that matches the laboratory-measured relative system response curve, but has the wavelengths increased by 3.3% (or 0.73 micron) achieves reasonable agreement between the measured and synthesised photometry.Comment: Accepted for publication in Publications of the Astronomical Society of Australia, 6 pages, 4 figures, 1 tabl

X-Ray scattering study of cellulosic arrangements in plant cell wall materials

Plant cell walls are the most important source of the polymer cellulose. The cell wall contains crystalline cellulose microfibrils embedded in a matrix of amorphous polymers. The most important of these amorphous polymers are the lignins and the hemi-celluloses. In this thesis we concentrate on the use of wide angle x-ray scattering as a tool to understand the important arrangements of cellulose in cell walls. Other experimental tools are used to supplement this information

An Ecological Study of Shale Barren Rock Cress (Arabis serotina Steele) at Little Fork Shale Barren, Pendleton County, West Virginia

Shale Barren Rock Cress (Arabis serotina Steele) was listed as a federally endangered species by the U.S. Fish and Wildlife Service in August 1989. As part of a cooperative agreement between the West Virginia Natural Heritage Program and the U.S. Navy, research was conducted in 1994 and 1995 at Little Fork Shale Barren (LFSB) to provide baseline information on the population dynamics of A. serotina and to study the vegetation and physical parameters associated with this shale barren community. Soil samples and plant community data were collected from 40 1-m2 circular plots for herbaceous vegetation and six 0.02-ha circular plots for overstory vegetation. Overstory vegetation was sampled on LFSB and on a mixed hardwood forest located on the north-northwest slope behind LFSB. Carex pensylvanica dominated the herbaceous layer of the shale barren, whereas Quercus prinus dominated the overstory on both the shale barren and the adjacent forested slope. The dominance of Q. prinus on both slopes is attributable to the low annual precipitation (84 cm yr-1) on the leeward side of the Allegheny Mountains. Stem density of overstory vegetation on the forest slope was approximately double that found on the barren. Basal area was also much greater on the forest slope than on the barren. Seven herbaceous species sampled are considered to be endemic or near-endemic to the mid-Appalachian shale barrens, including A. serotina, Paronychia montana, Calystegia spithamaea ssp. Purshiana, Antennaria virginica, Scutellaria ovata, Allium oxyphilum, and Phlox subulata. Comparison of soils between LFSB and the forest slope showed significant differences in NO3-N and pH of the water extraction (both higher on LFSB) at p ≤ 0.05. LFSB also had significantly higher NH4-N and pH of the KC1 extraction at p ≤ 0.10. Canonical correspondence analysis (CCA) showed no significant correlation between A. serotina and any of the measured soil variables. CCA did appear to indicate some response of total species composition to a soil NO3-N gradient. Gradients of soil factors appear to vary in a patchy fashion, perhaps dependent on historical and concurrent rates of litter accumulation rather than direct relation to an elevational gradient. The A. serotina population on LFSB was shown to be extremely variable with respect to both spatial and temporal changes in population structure. The population declined from 880 individuals in 1992 to only 96 individuals in 1995. These population changes appear to result from the sensitivity of this species to high temperatures coupled with low precipitation early in the growing season, but herbivory, fungal infection, stochastic processes, and human disturbance may also be involved. In July 1995, 71% of rosettes and 91% of bolting plants showed evidence of some type of herbivory. Also, mortality was shown to be substantial within a single growing season for both rosettes and bolting plants. Because mortality appeared to be highest from July through August, recommendations are made to expand the August 15 to September 5 sampling period recommended by the A. serotina Recovery Task Force and the Shale Barren Protection Strategy Group

Investigating the Improvement in Science Achievement Among Fifth Grade Science Students When Using the Instructional Design Model

The purpose of this study is to determine if the Instructional Design Model will improve science achievement. The study addressed the problem of low science achievement among 93 Grade 5 students. The theoretical framework that was applied to this study was developed by Ralph Tyler in 1949. The researcher believed that Tyler’s four-process curriculum planning approach guided teachers to look differently at teaching and learning. This model assisted teachers in developing lessons that used the Instructional Design Model and produced objectives that reflect their classroom goals, impacted curriculum, and increased the understanding of science concepts. The school administered a multiple choice, twenty-item pretest a unit of instruction to the Grade 5 students. The teachers participated in a pre-interview, received professional development on the Instructional Design Model, attended common planning meetings to develop lessons, delivered the lessons, and participated in a post-interview. The teachers taught a four-week unit and each teacher was observed every other week for one class period. After the four-week period the teacher administered the posttest to the students; which, was the same test as the pretest to the Grade 5 students. A convergent mixed methods design was used; in order to collect data in this type of design, the qualitative and quantitative data were collected in a lateral fashion, analyzed separately, and then merged together. An analysis of the data revealed the degree to which the use of Tyler’s Instructional Design Model in Grade 5 science classes in the target district would affect student achievement in science. The results of the elementary school’s scores were compared to the pre and post assessment data and determined that use of the Instructional Design Model significantly impacted post-test results