The Response of High School Students in a Trimester Term

These days, most high schools are usually on semester terms. However, there are still some that use trimester terms, three 12-week trimesters, compared to two 17-week semesters. This research takes a look at how students handle a transition or routine change in the middle of the trimester. The 2nd trimester had their routine changed mid-trimester and observations were made on their behavior. A survey was also given to them questioning how their transition went from having the regular teacher and a student teacher. The 3rd trimester classes were also observed and given a survey. It was a little different for the 3rd trimester because they started off the trimester with the student teacher and were used to the rules and did not experience a transitional period

Cleaner, Greener, Healthier: A Prescription for Stronger Canadian Environmental Laws and Policies by David R. Boyd

Review of David R. Boyd\u27s Cleaner, Greener, Healthier: A Prescription for Stronger Canadian Environmental Laws and Policies

Low-thrust vehicles concept studies

Low thrust chemical (hydrogen-oxygen) propulsion systems configured specifically for low acceleration orbit transfer of large space systems were studied in order to provide the required additional data to better compare new, low thrust chemical propulsion systems with other propulsion approaches such as advanced electric systems. Study results indicate that it is cost-effective and least risk to combine the low thrust OTV and stowed spacecraft in a single 65 K shuttle. Mission analysis indicates that there are 25 such missions, starting in 1987. Multiple shuttles (LSS in one, OTV in another) result in a 20% increase in LSS (SBR) diameter over single shuttle launches. Synthesis and optimization of the LSS characteristics and OTV capability resulted in determination of the optimum thrust-to-weight and thrust level. For the space based radar with radial truss arms (center thrust application), the optimum thrust-to-weight (maximum) is 0.1, giving a thrust of 2000 lb. For the annular truss (edge-on thrust application) the structure is not as sensitive, and thrust of 1000 lb appears optimum. For the geoplatform, optimum T/W is .15 (3000 lb thrust). The effects of LSS structure material, weight distribution, and unit area density were evaluated, as were the OTV engine thrust transient and number of burns

Detailed Spectral Analysis of the Type Ib Supernova 1999dn. Paper I: Hydrogen-free Models

We present spectral fits to five epochs of the typical Type Ib supernova 1999dn using the generalized, non-LTE, stellar atmospheres code PHOENIX. Our goal is threefold: to determine basic physical properties of the supernova ejecta, such as velocity, temperature, and density gradients; to reproduce He I absorption lines by invoking non-thermal excitation; and, to investigate possible spectral signatures of hydrogen, especially a feature around 6200 Angstrom, which has been attributed to high velocity $H_\alpha$. Our models assume an atmosphere with uniform composition devoid of any hydrogen. Our model spectra fit the observed spectra well, successfully reproducing most of the features, including the prominent He I absorptions. The most plausible alternative to $H_\alpha$ as the source of the 6200 Angstrom feature is a blend of Fe II and Si II lines, which can be made stronger to fit the observed feature better by increasing the metallicity of the ejecta. High-metallicity models fit well at early epochs, but not as well as solar-metallicity models after maximum light. While this blend of metal lines is a reasonable explanation of the source of the 6200 Angstrom feature, it is still important to investigate hydrogen as the source; therefore, a second paper will present models that include a thin shell of hydrogen around the main composition structure.Comment: 24 pages, 11 figures, 2 tables, submitted to Ap

A gyroscope calibration analysis for the Gamma Ray Observatory (GRO)

Current documentation and software do not adequately address the calculation and use of the optimal weight matrices involved in calibrating inertial reference units (IRU). Several facets of the GRO IRU calibration as it relates to the bias and misalignment weighting matrices are investigated. The physical meaning and use of the bias and misalignment weight matrices in IRU calibration are examined. The relation of the weighting and the final biases, misalignments, and their corrections are pursued. Methods for determining reliable, realistic weighting matrices to be used in the GRO IRU calibration (IRUCAL) utility are determined. Possible correlations among observation uncertainties are also explored. For the undetermined case where the maneuvers are insufficient to identify all calibration parameters, the weighting matrices allow as much information as possible to be extracted from the measurements. Finally, applicable simulated flight data are used, incorporating the appropriate calibration maneuvers, to test the weighting matrices in the IRUCAL utility, and examine correlation effects

Splitting Scales: Conflicting National and Regional Attempts to Manage Commercial Aquaculture in the Exclusive Economic Zone

Like other environmental resources subject to public use, various interest groups struggle over joint management of scarce fisheries resources. Further, differing goals for resource management, such as financial goals versus conservation goals, frequently pit regional groups against one another. In some cases, regional interests may conflict with overall national interests. As goes the water and the air, so go the fish