Semiconductor Surface Studies

Contains reports on one research project.Joint Services Electronics Program (Contract DAAG29-83-K-0003

Amateur Astronomy Research Telescope

The ERAU Amateur Astronomy Club Research Team is designing and building an amateur research telescope. The primary goal is high portability and compactness, with no compromise of optical quality. The team began with a set of mirrors pre-owned by the Amateur Astronomy Club, and will be constructing the telescope frame from medium density particle board. In the traditional style of John Dobson, the secondary mirror will be mounted on a truss system. This will reduce the weight and size of the telescope during transportation, as it can be disassembled and transported in a very small area. The primary purpose of the telescope is to observe and catalog messier objects in the night sky. After completion of the Messier Catalog, it shall be presented before physics faculty of ERAU

Voyager 2 Observations of Plasma and Pressure Pulses

This paper provides the latest data from Voyager 2 on plasma characteristics in the heliosheath including the observations of pressure waves in the plasma and particle data. Models and observations show that solar transients drive pressure waves through the heliosphere. Pressure pulses that could drive heliosheath waves are observed near the previous solar maximum upstream of the termination shock. We show that the most recent data is consistent with the presence of pressure waves and compare the heliosheath waves with the pressure increases in the heliosheath. The magnetic field is better correlated with density and galactic cosmic ray intensities in the supersonic solar wind than in the heliosheath. The galactic cosmic rays are correlated with the plasma and particles with a ~30-day lag in both the supersonic wind and heliosheath

Calibrating Type Ia Supernovae using the Planetary Nebula Luminosity Function I. Initial Results

We report the results of an [O III] lambda 5007 survey for planetary nebulae (PN) in five galaxies that were hosts of well-observed Type Ia supernovae: NGC 524, NGC 1316, NGC 1380, NGC 1448 and NGC 4526. The goals of this survey are to better quantify the zero-point of the maximum magnitude versus decline rate relation for supernovae Type Ia and to validate the insensitivity of Type Ia luminosity to parent stellar population using the host galaxy Hubble type as a surrogate. We detected a total of 45 planetary nebulae candidates in NGC 1316, 44 candidates in NGC 1380, and 94 candidates in NGC 4526. From these data, and the empirical planetary nebula luminosity function (PNLF), we derive distances of 17.9 +0.8/-0.9 Mpc, 16.1 +0.8/-1.1 Mpc, and 13.6 +1.3/-1.2 Mpc respectively. Our derived distance to NGC 4526 has a lower precision due to the likely presence of Virgo intracluster planetary nebulae in the foreground of this galaxy. In NGC 524 and NGC 1448 we detected no planetary nebulae candidates down to the limiting magnitudes of our observations. We present a formalism for setting realistic distance limits in these two cases, and derive robust lower limits of 20.9 Mpc and 15.8 Mpc, respectively. After combining these results with other distances from the PNLF, Cepheid, and Surface Brightness Fluctuations distance indicators, we calibrate the optical and near-infrared relations for supernovae Type Ia and we find that the Hubble constants derived from each of the three methods are broadly consistent, implying that the properties of supernovae Type Ia do not vary drastically as a function of stellar population. We determine a preliminary Hubble constant of H_0 = 77 +/- 3 (random) +/- 5 (systematic) km/s/Mpc for the PNLF, though more nearby galaxies with high-quality observations are clearly needed.Comment: 25 pages, 12 figures. Accepted for publication by the Astrophysical Journal. Figures degraded to comply with limit. Full paper is available at: http://www.as.ysu.edu/~jjfeldme/pnlf_Ia.pd

Restoration of Aspen-Dominated Ecosystems in the Lake States

A reserve tree method (RTM) of harvesting was installed in six 70 to 75 year old aspen dominated stands to determine if retaining 10 to 15 dominant aspen per acre would decrease sucker density to facilitate restoration of a conifer component. A reserve shelterwood cut was applied to three additional stands to evaluate performance of white pine planted under 50% crown cover. After the first full growing season following harvest, 96% of the RTM harvested areas were stocked; sucker density averaged 27000 per acre versus 38.2 k per acre on a clearcut control, 41% greater. Basal diameter of dominant suckers averaged 0.45 inch, 28% greater than the control, and mean height was 60 inches, 33% greater. The control site had 3.1k stems per acre of associated commercial species versus 5.8 k on the RTM sites, an 87% difference. Four of the nine stands have been planted; first-year survival ranged from 75% to near 100%. The RTM shows promise for reducing sucker density, increasing their early growth, maintaining species diversity, and providing abundant regeneration of commercial species on a high proportion of the areas harvested. Early results indicate that both the RTM and shelterwood methods can facilitate restoring a component of native conifer species in these ecosystems

The Use of an Optical Measurement System to Monitor Sports Performance

The purpose of this study was to compare ground contact time between an optical measurement system and a force platform. Participants in this study included six collegiate level athletes who performed drop jumps and sprint strike steps for a total of 15 repetitions each. Ground contact data was simultaneously collected from an optical measurement system and a force platform, at a sampling frequency of 1000 Hz. Data was then analyzed with Pearson’s correlation and paired sample t-tests. The measures from the optical measurement system were found to be significantly higher (p \u3c 0.001) than measures from the force platform in both conditions. Although significantly different, the extremely large relationships (0.979, 0.993) found between the two devices suggest the optical sensor is able to detect similar changes in performance to that of a force platform. Practitioners may continue to utilize optical sensors to monitor performance as it may provide a superior user-friendly alternative to more traditional based monitoring procedures, but must comprehend the inherent limitations due to the design of the optical sensors

Evaluating Software Development: A Case Study with Pasture Land Management (PLMS) Grazing Software

A process for evaluating and improving public domain software is presented for agents and faculty who author software and Web-based training. Extension, education, and conservation employees participated in workshops to learn about a Pasture Land Management System software program that enables farmers to experiment with alternative grazing methods. Users were questioned at initial workshop training and again 6 months later. The workshop evaluation showed concern about the software complexity. The follow-up questionnaire revealed the respondents\u27 priorities for technical improvements. The authors used the participants\u27 feedback to evaluate existing problems and prioritize improvements in the usability and functionality of the software