Conceptual design studies and experiments related to cavity exhaust systems for nuclear light bulb configurations

Investigations of various phases of gaseous nuclear rocket technology have been conducted. The principal research efforts have recently been directed toward the closed-cycle, vortex-stabilized nuclear light bulb engine and toward a small-scale fissioning uranium plasma experiment that could be conducted in the Los Alamos Scientific Laboratory's Nuclear Furnace. The engine concept is based on the transfer of energy by thermal radiation from gaseous fissioning uranium, through a transparent wall, to hydrogen propellant. The reference engine configuration is comprised of seven unit cavities, each having its own fuel transparent wall and propellant duct. The basic design of the engine is described. Subsequent studies performed to supplement and investigate the basic design are reported. Summaries of other nuclear light bulb research programs are included

Evolving collective behavior in an artificial ecology

Collective behavior refers to coordinated group motion, common to many animals. The dynamics of a group can be seen as a distributed model, each “animal” applying the same rule set. This study investigates the use of evolved sensory controllers to produce schooling behavior. A set of artificial creatures “live” in an artificial world with hazards and food. Each creature has a simple artificial neural network brain that controls movement in different situations. A chromosome encodes the network structure and weights, which may be combined using artificial evolution with another chromosome, if a creature should choose to mate. Prey and predators coevolve without an explicit fitness function for schooling to produce sophisticated, nondeterministic, behavior. The work highlights the role of species’ physiology in understanding behavior and the role of the environment in encouraging the development of sensory systems

Solar sustained plasma/absorber conceptual design

A space power system concept was evaluated which uses concentrated solar energy to heat a working fluid to temperatures as high as 4000 K. The high temperature working fluid could be used for efficient electric power production in advanced thermal or magnetohydrodynamic conversion cycles. Energy absorber configurations utilizing particles or cesium vapor absorber material were investigaed. Results of detailed radiant heat transfer calculations indicated approximately 86 percent of the incident solar energy could be absorbed within a 12-cm-dia flowing stream of gas borne carbon particles. Calculated total energy absorption in the cesium vapor seeded absorber configuration ranged from 34 percent to 64 percent of the incident solar energy. Solar flux concentration ratios of between approximately 3000 and 10,000 will be required to sustain absorber temperatures in the range from 3000 K to 4000 K

New, nearby bright southern ultracool dwarfs

We report the discovery of twenty-one hitherto unknown bright southern ultracool dwarfs with spectral types in the range M7 to L5.5, together with new observations of a further three late M dwarfs previously confirmed. Three more objects are already identified in the literature as high proper motion stars;we derive their spectral types for the first time. All objects were selected from the 2MASS All Sky and SuperCOSMOS point source databases on the basis of their optical/near-infrared colours, $J$-band magnitudes and proper motions. Low resolution (R $\sim$ 1000) $JH$ spectroscopy with the ESO/NTT SOFI spectrograph has confirmed the ultracool nature of 24 targets, out of a total of 25 candidates observed. Spectral types are derived by direct comparison with template objects and compared to results from H$_2$O and FeH indices. We also report the discovery of one binary, as revealed by SOFI acquisition imaging; spectra were taken for both components. The spectral types of the two components are L2 and L4 and the distance $\sim$ 19 pc. Spectroscopic distances and transverse velocities are derived for the sample. Two $\sim$ L5 objects lie only $\sim$ 10 pc distant. Such nearby objects are excellent targets for further study to derive their parallaxes and to search for fainter, later companions with AO and/or methane imaging.Comment: 11 pages, 10 figures, accepted to MNRA

Geological framework model and surface data for the area south of Ammanford

Background The original objective of this work was to a ssemble a 1:50 000 (50k) resolution 3D Geological Framework Model for an area south of Ammanfor d. The model was to have two main purposes: 1. To form the basis for a communication tool to present the 3D geological understanding of the area to a range of stakeholders; and 2. To support the reinterpretation of th e geological succession mapped at surface. This study specifically excludes the further development of th e Framework Model to include hydrogeology, hydrochemistry or rock mechanics and does not include any consideration of potentially suitable resources such as Coal Bed Methane. This report provides the explanation of the me thodology and how this model was generated. Additional outputs of the study include: 1. An ArcGIS project containing the da ta used to compile the model; and 2. Surface observations of the geology collected foll owing Sigma workflows, held in a GIS. Development of a 3D geological framework model A 1:50 000 resolution 3D geological framework model was successfully constructed for the study area using the Geological Surveying and Investigation in 3D (GSI3D) software package, developed partly in house at BGS, which can be used readily by geologists to construct a series of cross-sections that can more clearly display the geological succession. Models of this type have the potential to be accessible to members of the public and used by geologists to assess the potential location of resources , not evident from traditi onal 2D geological maps. The approach followed was to construct a fence diagram of 12 cross-sections using GSI3D. These sections encompass the entire study area and using the geologists’ expert knowledge to incorporate surface and subsurface data (24 deep boreholes and structural contour information from published geological maps) provide an inte rpretation of the geolog ical succession at Bed, Member and Formation level, consistent with BGS 1:50 000-scale (50k) geological maps of the area

Calculation of three-dimensional compressible laminar and turbulent boundary flows. Three-dimensional compressible boundary layers of reacting gases over realistic configurations

A three-dimensional boundary-layer code was developed for particular application to realistic hypersonic aircraft. It is very general and can be applied to a wide variety of boundary-layer flows. Laminar, transitional, and fully turbulent flows of compressible, reacting gases are efficiently calculated by use of the code. A body-oriented orthogonal coordinate system is used for the calculation and the user has complete freedom in specifying the coordinate system within the restrictions that one coordinate must be normal to the surface and the three coordinates must be mutually orthogonal

Reforming Primary Health Care: A Nursing Perspective. Contributing to health care reform, issues and challenges.

The aim of this report as outlined in the commissioning brief is three fold: • “To describe the role of the nurse workforce in the development and implementation of primary health care reform at supra-national, national and local levels. • To critically review the evidence base and identify, from a nursing workforce perspective, key factors in the practice environment which act to inhibit the development of PHC reform or, conversely, have significant potential to facilitate/strengthen it. • To develop a clearly argued, evidence-based policy brief, including illustrative case study examples, which articulates the important contribution that nurses can make in future health sector reform focused on primary care development/enhancement and the delivery of health equity goals, and contributes to the ongoing dialogue about key drivers in achieving a paradigm shift to primary health care.

Performance and Inbreeding Depression of Populations Representing Seven Eras of Maize Breeding

Improvements in maize (Zea mays L.) yields have been due to improvements in production inputs as well as to cultivars that have improved performance at low levels of inputs and the ability to respond to high levels of inputs used on today\u27s farms. The objectives of this study were to estimate genetic rates of gain and inbreeding depression by evaluating populations representative of each of seven eras of maize breeding. Inbred lines representative of each of the six decades (eras) from 1930 to 1980 were intermated to produce six era populations. A seventh, pre-1930 era, was represented by the open-pollinated cultivars (OP) ‘Reids Yellow Dent’ and ‘Lancaster Sure Crop’. These eight entries along with three check populations were evaluated in six Iowa environments. In addition, to assess changes in the rates of inbreeding depression, S1 bulk populations of the six era populations and OP and S2 bulks of the three check populations were also evaluated. The average genetic rate of gain for grain yield was 0.52 ± 0.04 Mg ha-1 era-1 when OP was included in the analysis. By assuming 10 yr per era, the yearly genetic rate of gain was 0.052 ± 0.004 Mg ha-1. The rates of genetic gain for percentage of stalk lodging and grain moisture at harvest were −5.1 ± 0.5% era-1 and 0.44 ± 0.09% era-1, respectively. The rate of inbreeding depression for yield increased steadily over eras, and the rate of inbreeding depression for Era 6 was double that for the OP. However, inbreeding depression as a percentage of the So mean showed no directional changes and was similar for all eras. These results indicate that breeders have been effective at selecting lines and hybrids with higher yields and resistance to lodging and the ability to produce higher yields under stress conditions. The increased rates of inbreeding depression for the more recent eras coupled with the increased performance of the S0 and S1 populations suggest that favorable allele frequencies were initially below 0.5 and have been increasing and]or that the more recent era populations are segregating at more loci