Advanced Evolution Of Massive Stars .4. Secondary Nucleosynthesis During Helium Burning

NSF GP-32051, GP-23282Astronom

Last Hired, First Fired? Black-White Unemployment and the Business Cycle

Past studies have tested the claim that blacks are the last hired during periods of economic growth and the first fired in recessions by examining the movement of relative unemployment rates over the business cycle. Any conclusion drawn from this type of analysis must be viewed as tentative because the cyclical movements in the underlying transitions into and out of unemployment are not examined. Using Current Population Survey data matched across adjacent months from 1989 to 2004, this paper provides the first detailed examination of labor market transitions for prime-age black and white men to test the last-hired, first-fired hypothesis. Considerable evidence is presented that blacks are the first fired as the business cycle weakens. However, no evidence is found that blacks are the last hired. Instead, blacks appear to be initially hired from the ranks of the unemployed early in the business cycle and later are drawn from non-participation. The narrowing of the racial unemployment gap near the peak of the business cycle is driven by a reduction in the rate of job loss for blacks rather than increases in hiring.race, unemployment, business cycle

The Otto-engine-equivalent vehicle concept

A vehicle comparison methodology based on the Otto-Engine Equivalent (OEE) vehicle concept is described. As an illustration of this methodology, the concept is used to make projections of the fuel economy potential of passenger cars using various alternative power systems. Sensitivities of OEE vehicle results to assumptions made in the calculational procedure are discussed. Factors considered include engine torque boundary, rear axle ratio, performance criteria, engine transient response, and transmission shift logic

Are the Perseus-Pisces chain and the Pavo-Indus wall connected?

A significant empty region was found between the southern Pavo- Indus (PI) wall and the northern Perseus-Pisces (PP) chain. This survey tests the reality of this void which may simply reflect previous poor sampling of the galaxies in this region. Redshifts for a magnitude selected sample of 379 galaxies were obtained covering the four UKST/SERC survey fields with Bt <= 17.0. All redshifts were obtained with the FLAIR multi-object spectroscopy system on the 1.2 m U.K. Schmidt Telescope at Siding Spring, Australia. Two highly significant density enhancements were found in the galaxy distribution at 133 Mpc and 200 Mpc (Ho=75 km/s/Mpc). We claim that no connexion exists between PP and PI. However, a southern extension of PP was detected and makes the total length of this chain of more than 150 Mpc.Comment: 14 pages, postscript including tables and figures

Effect of blockage ratio on drag and pressure distributions for bodies of revolution at transonic speeds

Experimental data were obtained in two wind tunnels for 13 models over a Mach number range from 0.70 to 1.02. Effects of increasing test-section blockage ratio in the transonic region near a Mach number of 1.0 included change in the shape of the drag curves, premature drag creep, delayed drag divergence, and a positive increment of pressures on the model afterbodies. Effects of wall interference were apparent in the data even for a change in blockage ratio from a very low 0.000343 to an even lower 0.000170. Therefore, models having values of blockage ratio of 0.0003 - an order of magnitude below the previously considered safe value of 0.0050 - had significant errors in the drag-coefficient values obtained at speeds near a Mach number of 1.0. Furthermore, the flow relief afforded by slots or perforations in test-section walls - designed according to previously accepted criteria for interference-free subsonic flow - does not appear to be sufficient to avoid significant interference of the walls with the model flow field for Mach numbers very close to 1.0

Transfer of household management skills from a board and care home to an experimental apartment via programming common stimuli

A random multielement design was used in two replications to assess the effectiveness of programming common stimuli to enhance the transfer of household management skills from a group home for mentally disabled adults to an experimental apartment. Salient stimulus items were taken from the subjects\u27 group homes (training site) and placed in an experimental apartment (testing site) as the participants were advancing through a program to teach them independent living skills. The results suggest that the transfer of household management skills was enhanced by programming in stimuli from the training site

A study of management effects on carbohydrate reserves in Gahi-1 pearlmillet

The permanent and semi-permanent pastures composed of perennial grasses and legumes seldom produce adequate amounts of forage during the hot, dry summer months. If these pastures are to be utilized to the fullest extent, some form of summer supplementary forage must be available during these periods of low production of the legume-grass pastures. The use of summer annual supplementary forage species is becoming more popular, especially with the dairy farmer, to partially solve this feed shortage problem. Pearlmillet (Pennisetum glaucum (L.) R. Br.) is one species that appears to be particularly well-suited for use as a summer supplemental forage grass in Tennessee and other southeastern states. It is a summer annual which grows better than most forage crops during the hot, dry, summer weather. It does not contain any prussic acid-forming glucosides or other known poisonous constituents. At the present time, it is more resistant to the pathogens that affect other plants such as Sudangrass (Sorghum sudanense (Piper) Stapf.). It produces more high quality forage during the summer than does most of the other grasses, and maintains a high level of production under unfavorable climatic conditions that often reduces the quality and production of perennial grasses. There is, however, a lack of knowledge of the basic management factors necessary to realize the greatest potential from this crop as a pasture, hay, silage, or soilage species. Information is lacking particularly in the area of carbohydrate reserves in relation to regrowth and production of high quality forage, as influenced by various management factors. Some research has been conducted on the cutting, grazing, and fertilization management of the crop in relation to the influences of management on regrowth, production, morphological development, and nitrogen content of the plants. However, just what Influences the carbohydrate reserves have on these factors, or what influences cutting height and nitrogen fertilization have on the reserve carbohydrates, are not known. With these problems in mind, an investigation was conducted in an attempt to answer the following questions: 1. How close to the soil surface can pearlmillet be cut and still produce good yields of high quality forage? 2. How does different cutting intensities affect total forage yield? 5. How does nitrogen fertilization and cutting intensities affect the rate and amount of regrowth? 4. How does nitrogen fertilization and cutting Intensities affect the amount of reserve carbohydrates available for utilization in initial regrowth? 5. Does the carbohydrate content of the basal stubble vary with different heights of stubble and different amounts of nitrogen fertilization? 6. How does cutting frequency affect the carbohydrate reserves? 7. Does carbohydrate reserves affect the rate of regrowth? 8. How accurate and useful is the refractometer in determining the carbohydrate content of plants? 9. How accurate and useful is the enthrone method of carbohydrate analysis for analyzing plant material

Effect of Sourdough Fermentation Parameters on Bread Properties

Sourdough is the oldest form of leavening which many believe was invented by the Egyptians. Bread leavened with a sourdough culture relies on the metabolism of naturally occurring lactic acid bacteria and wild yeasts. Historically there were many ties between beer brewing and bread baking. In the fourteen and fifteen hundreds, it was discovered that brewers yeast could also be used to leaven bread. Up until the invention of commercial yeast in the nineteenth century, sourdough cultures and brewers yeast where the only bread leavening methods. By 1910, traditional sourdough was much less common because bread made with commercial yeast was much faster and easier, and produced a more consistent product. The positive qualities of sourdough bread were unfortunately overlooked because of the convenience that commercial yeast offered. Phytic acid makes up about 1% of wheat and rye flours, and reduces the bioavailability of calcium, magnesium, and iron by forming complexes with the divalent cations. Phytic acid also inhibits enzymes in the digestive system needed to breakdown starch and protein. This explains why some people experience discomfort from eating whole grain wheat products. Sourdough bacteria breakdown phytic acid and “predigest†the grain during the proofing process which releases easy to digest micronutrients. Specific sourdough lactic acid bacteria breaks down sucrose to form exopolysaccharides that contributes to bread volume, texture, and dietary fiber content. This increase in fiber slows the digestion of the sourdough bread and does not cause rapid blood sugar spikes like a commercial white bread often does. The objective of this study was to gain a better understanding of how fermentation time and temperature affect sourdough production and give insight to why it is sometimes more acceptable than non-fermented breads to the human digestive system. Three identical batches of sourdough bread, 9 samples per batch, were produced and analyzed. Samples 26-2, 26-4, 26-8, and 26-12 were fermented at 26°C and samples 4-14, 4-26, 4-38, and 4-50 were fermented at 4°C to observe the affect of temperature on fermentation. Bread samples were analyzed for moisture, loaf height, and protein content, and parallel dough samples where analyzed for volatiles. This experiment shows evidence of protein hydrolysis with data indicating an increase in alcohol extractable protein as fermentation time increases. It was observed that fermentation temperature, environment (presence or lack of O2), and time/duration all effect the bread qualities

Discovery of a Large-scale Wall in the Direction of Abell 22

We report on the discovery of a large-scale wall in the direction of Abell 22. Using photometric and spectroscopic data from the Las Campanas Observatory and Anglo-Australian Telescope Rich Cluster Survey, Abell 22 is found to exhibit a highly unusual and striking redshift distribution. We show that Abell 22 exhibits a foreground wall-like structure by examining the galaxy distributions in both redshift space and on the colour-magnitude plane. A search for other galaxies and clusters in the nearby region using the 2dF Galaxy Redshift Survey database suggests that the wall-like structure is a significant large-scale, non-virialized filament which runs between two other Abell clusters either side of Abell 22. The filament stretches over at least >40 Mpc in length and 10 Mpc in width at the redshift of Abell 22.Comment: 6 pages, 4 figures, accepted for publication in MNRAS letter

Galaxy threshing and the origin of intracluster stellar objects

We numerically investigate dynamical evolution of non-nucleated dwarf elliptical/spiral galaxies (dE) and nucleated ones (dE,Ns) in clusters of galaxies in order to understand the origin of intracluster stellar objects, such as intracluster stars (ICSs), GCs (ICGCs), and ``ultra-compact dwarf'' (UCDs) recently discovered by all-object spectroscopic survey centred on the Fornax cluster of galaxies. We find that the outer stellar components of a nucleated dwarf are removed by the strong tidal field of the cluster, whereas the nucleus manages to survive as a result of its initially compact nature. The developed naked nucleus is found to have physical properties (e.g., size and mass) similar to those observed for UCDs. We also find that the UCD formation processes does depend on the radial density profile of the dark halo in the sense that UCDs are less likely to be formed from dwarfs embedded in dark matter halos with central `cuspy' density profiles. Our simulations also suggest that very massive and compact stellar systems can be rapidly and efficiently formed in the central regions of dwarfs through the merging of smaller GCs. GCs initially in the outer part of dE and dE,Ns are found to be stripped to form ICGCs.Comment: 6 pages and 3 figures (JPG file for Fig. 1), in the proceedings of IAU 217 ``Recycling intergalactic and interstellar matter'