Ab Initio Calculations on the H_(2)+D_(2)=2HD Four‐Center Exchange Reaction. I. Elements of the Reaction Surface

We present the results of ab initio calculations on some interesting regions of the reaction surface for the four‐center exchange reaction H_(2)+D_(2)=2HD. These calculations, which use a minimum basis set of Slater orbitals, indicate that for all geometries appropriate to the transition state of the reaction, a barrier height of at least 148 kcal/mole is present. This is far greater than the energy required to produce free radicals and more than three times the experimental energy of activation, 42 kcal/mole. Considering the sources and magnitudes for errors due to correlation and basis set restrictions, we estimate the barrier height for this exchange reaction to be 132 ± 20 kcal/mole exclusive of zero‐point energies. In this paper we discuss the surface as determined by configuration interaction techniques. We find that the most favorable geometries for the exchange reactions are the square, rhombus, and kite configurations. However, all of these states are unstable with respect to H_(2) + 2H. In addition we find no evidence of collision complexes for any of the likely transition state geometries. In the following paper we will examine the G1 wavefunctions for this system in order to obtain an understanding of the factors responsible for the shape of the surface

NASA-DoD Lead-Free Electronics Project: Vibration Test

Vibration testing was conducted by Boeing Research and Technology (Seattle) for the NASA-DoD Lead-Free Electronics Solder Project. This project is a follow-on to the Joint Council on Aging Aircraft/Joint Group on Pollution Prevention (JCAA/JG-PP) Lead-Free Solder Project which was the first group to test the reliability of lead-free solder joints against the requirements of the aerospace/miLItary community. Twenty seven test vehicles were subjected to the vibration test conditions (in two batches). The random vibration Power Spectral Density (PSD) input was increased during the test every 60 minutes in an effort to fail as many components as possible within the time allotted for the test. The solder joints on the components were electrically monitored using event detectors and any solder joint failures were recorded on a Labview-based data collection system. The number of test minutes required to fail a given component attached with SnPb solder was then compared to the number of test minutes required to fail the same component attached with lead-free solder. A complete modal analysis was conducted on one test vehicle using a laser vibrometer system which measured velocities, accelerations, and displacements at one . hundred points. The laser vibrometer data was used to determine the frequencies of the major modes of the test vehicle and the shapes of the modes. In addition, laser vibrometer data collected during the vibration test was used to calculate the strains generated by the first mode (using custom software). After completion of the testing, all of the test vehicles were visually inspected and cross sections were made. Broken component leads and other unwanted failure modes were documented

Effects of Irradiated Oils on Photographic Films

During the past two years, there has been considerable discussion on the question of the emission of ultra-violet light by cod liver oil. Our experiments have confirmed the opinion that no radiations are emitted which can penetrate plates of fused quartz one millimeter in thickness. However, an image is produced on a photographic film placed directly above the oil, an effect which is attributed to a direct chemical action. We have also found that other oils which would not produce images on the photographic film can be activated by ultra-violet light so that they act like cod liver oil. Different oils can be activated in different degrees, which is similar to the results obtained with the production of anitirachitic properties in them by ultra-violet light

Work in Progress: Transformational Change in a Masters-level Integrated Capstone Design Course that Partners Industry and Academia

Integrated capstone design courses in civil engineering pose a major challenge for educators because of the breadth of topics covered. Partnering with industry has historically provided a way to alleviate some of these challenges and provide a more authentic design experience. While external partnership in capstone design courses can provide added authenticity as well as fringe benefits such as networking opportunities, there are risks associated with an industry-driven approach. We also argue there is a need to shift from an emphasis on product to pedagogy in capstone design and that authenticity from industry is not an end in itself. In this work-in-progress paper, we present our project to reimagine the integrated capstone design course at a large, public research university in the United Kingdom. This project has three major goals: (1) Develop an understanding of how to balance industry involvement; (2) Generate mechanisms for sustainable adoption of changes; and (3) Evaluate short- and long-term student outcomes for the course. We will present an overview of our intended curricular changes as well as research and evaluation plans to date. This project fits uniquely in the current literature on engineering design education in that it centers around a masters-level course and challenges the notion of what constitutes healthy industry partnership. As a starting point, our first research question considers how the current capstone design course came to be a primarily outsourced effort and what factors impacted this organizational shift to lower academic ownership from within the department

Using American Sign Language to Support Sight Word Acquisition in English Learners

English Learners constitute a growing, and important, portion of our school communities, yet the research base regarding evidence-based practices to support effective instruction for English Learners is minimal, especially for those with disabilities. American Sign Language has effectively supplemented curriculum for different student populations, but there has been little research on how sign language can be used to teach English Learners. Sight word acquisition is often a challenge for English Learners so this alternating treatment, single subject research design explored if adding American Sign Language to sight word instruction of first grade English Learners would increase learning of sight words compared to the typical drill-and-practice. Results indicated that American Sign Language can be used to help students experience mastery of sight words and also engage them in the process of learning

The Simulation of Resonant Tunneling Diodes

The goal of this project is to improve the simulation of an electrical device known as a Resonant Tunneling Diode (RTD). Diodes are in most electronic devices today, but RTDs have 10 times greater switching speeds than regular diodes. This increase in efficiency would have impacts from supercomputers to the next big cell phone. The increased functionality of the simulation tool will come from implementing more recent mathematical solvers and modeling techniques. The simulation tool makes use of a variant of Non-Equilibrium Green Functions (NEGF) with an effective mass approximation. The two contacts are treated as equilibrium regions and the channel as a non-equilibrium region. The tool is capable of simulating multi-barrier devices and allows for significant user input. The output is being developed to allow the user to see the results of bias sweeps as well as side-by-side graphs of conduction band edge, transmission probability, energy resolved current and current-voltage characteristics. Upon completion of the tool it will become available through nanoHUB, a scientific and engineering gateway providing interactive online resources. This will allow for the broad impact in classrooms, laboratories, and industries around the world. RTDs will become significantly more important as our electronics continue to grow in power and shrink in size. The simulation tool will continue to be updated with future advancements in technology

Studies on the Effect of Ultra-Violet Rays upon Yeast Metabolism - I. The Effect of Ultra Violet Light upon the Medium

74. Studies on the effect Exposure of the medium (composed of optimum concentrations of salts and sugar) to ultra-violet light renders it less effective for the growth of yeast. The development of the toxicity increases with duration and intensity of irradiation. An exposure of seven hours through quartz at about l5 cm from a quartz mercury vapor lamp affects the medium in such a way that yeast will show practically no growth in the medium. The work is being continued in order to obtain quantitative results and to explain the phenomenon