Drive system employing frictionless bearings including superconducting matter

A device employing frictionless bearings including a mass of superconductor material having a superconducting temperature Tc above about 77° K, magnet having an axis of symmetry being levitated from said mass of superconductor material so as to be rotatable about its axis of symmetry, and a support member attached to the magnet. The support member is driven so as to cause the magnet to rotate about its axis of symmetry. It also includes a frictionless commutator where a signal beam is intermittently interrupted by a member attached to the magnet, the support member being driven so as to cause the magnet to rotate about its axis of symmetry

Impact Broadening, Shifting, and Asymmetry of the D1 and D2 Lines of Alkali-Metal Atoms Colliding With Noble-Gas Atoms

The Anderson Talman theory of spectral line broadening is used together with potential energy curves calculated at the spin-orbit multi-reference configuration interaction level to compute broadening, shifting, and asymmetry coefficients of the D1 and D2 lines of alkali-metal atoms M, as they collide with noble gas atoms N, where M=K, Rb, and Cs, and N=He, Ne, and Ar. Our calculated coefficients are compared to experimental results for a variety of temperatures. In all cases general agreement is observed for the broadening coefficients, while significant disagreement is observed for the shifting coefficients. We also compare our K+He broadening and shifting results with fully quantum-mechanical calculations that employ the Baranger theory of collisional line broadening, and we compare our results with other semiclassical calculations. As with the comparison to experiment, closer agreement is observed for the broadening coefficients while the shifting coefficients exhibit significant disagreement. We use the natural variation between the difference potentials of the nine M+N pairs to explore the relationship between potential and line shape as determined by Anderson-Talman theory and develop a picture for the mechanism that underlies the general agreement between theoretical and experimental results on the broadening coefficient and the general disagreement on shifting coefficients

Effect of Ar(3p\u3csup\u3e5\u3c/sup\u3e4p; 2p)+M -\u3e Ar(3p\u3csup\u3e5\u3c/sup\u3e4s; 1s)+M branching ratio on optically pumped rare gas laser performance

Optically pumped rare gas laser performance is analyzed as a function of the Ar(3p54p; 2p) + M → Ar(3p54s; 1s) + M branching ratios. Due to the uncertainty in the branching ratios, a sensitivity study is performed to determine the effect on output and absorbed pump laser intensities. The analysis is performed using a radio frequency dielectric barrier discharge as the source of metastable production for a variety of Argon in Helium mixtures over pressures ranging from 200 to 500 Torr. Peak output laser intensities show a factor of 7 increase as the branching ratio is increased from 0.25 to 1.00. The collection of Ar* in Ar(1s4) is inversely proportional to the branching ratio and decreases output laser intensity by reducing the density of species directly involved with lasing

Analytic Non-adiabatic Derivative Coupling Terms for Spin-orbit MRCI Wavefunctions. I. Formalism

Analytic gradients of electronic eigenvalues require one calculation per nuclear geometry, compared to at least 3n + 1 calculations for finite difference methods, where n is the number of nuclei. Analytic nonadiabatic derivative coupling terms (DCTs), which are calculated in a similar fashion, are used to remove nondiagonal contributions to the kinetic energy operator, leading to more accurate nuclear dynamics calculations than those that employ the Born-Oppenheimer approximation, i.e., that assume off-diagonal contributions are zero. The current methods and underpinnings for calculating both of these quantities, gradients and DCTs, for the State-Averaged MultiReference Configuration Interaction with Singles and Doubles (MRCI-SD) wavefunctions in COLUMBUS are reviewed. Before this work, these methods were not available for wavefunctions of a relativistic MRCI-SD Hamiltonian. Calculation of these terms is critical in successfully modeling the dynamics of systems that depend on transitions between potential energy surfaces split by the spin-orbit operator, such as diode-pumped alkali lasers. A formalism for calculating the transition density matrices and analytic derivative coupling terms for such systems is presented

Metastable Ar(1s\u3csub\u3e5\u3c/sub\u3e) Density Dependence on Pressure and Argon-helium Mixture in a High Pressure Radio Frequency Dielectric Barrier Discharge

Simulations of an α-mode radio frequency dielectric barrier discharge are performed for varying mixtures of argon and helium at pressures ranging from 200 to 500 Torr using both zero and one-dimensional models. Metastable densities are analyzed as a function of argon-helium mixture and pressure to determine the optimal conditions, maximizing metastable density for use in an optically pumped rare gas laser. Argon fractions corresponding to the peak metastable densities are found to be pressure dependent, shifting from approximately 15% Ar in He at 200 Torr to 10% at 500 Torr. A decrease in metastable density is observed as pressure is increased due to a diminution in the reduced electric field and a quadratic increase in metastable loss rates through Ar*2 formation. A zero-dimensional effective direct current model of the dielectric barrier discharge is implemented, showing agreement with the trends predicted by the one-dimensional fluid model in the bulk plasma

Space Station Freedom automation and robotics: An assessment of the potential for increased productivity

This report presents the results of a study performed in support of the Space Station Freedom Advanced Development Program, under the sponsorship of the Space Station Engineering (Code MT), Office of Space Flight. The study consisted of the collection, compilation, and analysis of lessons learned, crew time requirements, and other factors influencing the application of advanced automation and robotics, with emphasis on potential improvements in productivity. The lessons learned data collected were based primarily on Skylab, Spacelab, and other Space Shuttle experiences, consisting principally of interviews with current and former crew members and other NASA personnel with relevant experience. The objectives of this report are to present a summary of this data and its analysis, and to present conclusions regarding promising areas for the application of advanced automation and robotics technology to the Space Station Freedom and the potential benefits in terms of increased productivity. In this study, primary emphasis was placed on advanced automation technology because of its fairly extensive utilization within private industry including the aerospace sector. In contrast, other than the Remote Manipulator System (RMS), there has been relatively limited experience with advanced robotics technology applicable to the Space Station. This report should be used as a guide and is not intended to be used as a substitute for official Astronaut Office crew positions on specific issues

Developing Conceptual and Methodological Foundations in Community Engagement

We describe the efforts of two related undergraduate projects to promote lasting social change in marginalized communities in the Dominican Republic and Nicaragua. The projects represent a test of the premise that undergraduate projects can engage academically based strategies and transcend good intentions to achieve effective community partnerships to improve health and health care. The projects proceed from a perspective and theory of marginalization and its consequences. Specifically, marginalization undermines individual and collective capacity to meet basic needs and efforts to thrive. Through strengthening social infrastructure, communities can overcome the effects of marginalization. Project work begins with annual medical clinics and, with the permission of community residents, team members conduct ethnographic descriptions of the communities and their health and health care concerns and resources. We use social network analysis (SNA) and geographic information system (GIS) techniques to describe social infrastructure. Working from those foundations, both projects have enabled increased social infrastructure. To date, we have observed increased communication among community residents, facilitated the development of community-endorsed five-year plans, and established partnerships with regional and international groups

Physical properties of glasses exposed to Earth-facing and trailing-side environments on LDEF

The exposure of 108 glass samples and 12 glass-ceramic samples to Earth-orbit environments permitted measurements which establish the effects of each environment. Examination of five glass types and one glass ceramic located on both the Earth-facing side and the trailing edge revealed no reduction in strength within experimental limits. Strength measurements subjected less than 5 percent of the sample surface area to stresses above 90 percent of the glass's failure strength. Seven micrometeorite or space debris impacts occurred on trailing edge samples. One of those impacts occurred in a location which was subjected to 50 percent of the applied stress at failure. Micrometeorite or space debris impacts were not observed on Earth-facing samples. The physical shape and structure of the impact sites were carefully examined using stereographic scanning electron microscopy. These impacts induce a stress concentration at the damaged region which influences mechanical strength. The flaw size produced by such damage was examined to determine the magnitude of strength degradation in micrometeorite or space-debris impacted glasses. Scanning electron microscopy revealed topographical details of impact sites which included central melt zones and glass fiber production. The overall crater structure is similar to much larger impacts of large meteorite on the Moon in that the melt crater is surrounded by shocked regions of material which fracture zones and spall areas. Residual stresses arising from shock compression and cooling of the fused zone cannot currently be included in fracture mechanics analyses based on simple flaw size examination

Shared morphological consequences of global warming in North American migratory birds

Increasing temperatures associated with climate change are predicted to cause reductions in body size, a key determinant of animal physiology and ecology. Using a four‐decade specimen series of 70 716 individuals of 52 North American migratory bird species, we demonstrate that increasing annual summer temperature over the 40‐year period predicts consistent reductions in body size across these diverse taxa. Concurrently, wing length – an index of body shape that impacts numerous aspects of avian ecology and behaviour – has consistently increased across species. Our findings suggest that warming‐induced body size reduction is a general response to climate change, and reveal a similarly consistent and unexpected shift in body shape. We hypothesise that increasing wing length represents a compensatory adaptation to maintain migration as reductions in body size have increased the metabolic cost of flight. An improved understanding of warming‐induced morphological changes is important for predicting biotic responses to global change.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153188/1/ele13434-sup-0001-Supinfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153188/2/ele13434.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153188/3/ele13434_am.pd