Rotational Splitting of Pulsational Modes

Mode splittings produced by uniform rotation and a particular form of differential rotation are computed for two-dimensional rotating 10 Mo ZAMS stellar models. The change in the character of the mode splitting is traced as a function of uniform rotation rate, and it is found that only relatively slow rotation rates are required before the mode splitting becomes asymmetric about the azimuthally symmetric (m=0) mode. Increased rotation produces a progressively altered pattern of the individual modes with respect to each other. Large mode splittings begin to overlap with the mode splittings produced by different radial and latitudinal modes at relatively low rotation rates. The mode splitting pattern for the differentially rotating stars we model is different than that for uniformly rotating stars, making the mode splitting a possible discriminant of the internal angular momentum distribution if one assumes the formidable challenge of mode identification can be overcome.Comment: 6 journal pages, 7 Figures, accepted by Ap

Determination of Faecal Contamination of the Groundwater Resources from Tano Districts of Ghana

This paper seeks to report on whether there are faecal contaminants in the groundwater resources within the Tano Districts, where people use groundwater as their source of drinking water and for other domestic purposes. Total Coliforms, Faecal Coliforms, Enterococci, E.coli and Salmonella were employed as faecal indicators in this study. Determination of these faecal indicators in the samples was done using the Most Probable Number (MPN) method. A simple random sampling method was employed to get the sample size of 15 wells. The results of this study indicate that the water in the selected wells had faecal contaminants, proved by the presence of the faecal determinants in the water samples collected The presence of these organisms is an indication that water within the wells from the study area has been faecally contaminated with animal or human faeces. These bacteria are used as faecal indicators as an evidence of possible sewage contamination because, they are commonly found in animal or human faeces. Therefore, the fact that these faecal indicators have been detected in water sampled from the selected wells means that pathogens might also be present. The study recommends treatment of the groundwater supplies or encourages the use of the home water treatment.In an attempt to solve the problem of the faecal contamination of the selected wells, a future research should be conducted to determine the source of faecal contamination of ground water in wells at the Tano Districts

Role of tropical Pacific SSTs in global medieval hydroclimate: A modeling study

The role of tropical Pacific SSTs in driving global medieval hydroclimate is assessed. Using fossil coral records from Palmyra Atoll, tropical Pacific sea surface temperature (SST) boundary conditions are derived for the period 1320-1462 A.D. These boundary conditions consist of La Niña-like mean state conditions in the tropical Pacific with inter-annual and decadal variability about that altered state. The reconstructed SSTs in the tropical Pacific are used to force a 16 member ensemble of atmospheric general circulation model (AGCM) simulations, coupled to a one layer ocean model outside of the tropical Pacific. The AGCM simulations of medieval climate are compared with modern climate simulations for the period 1856-2005 A.D. and are shown to reproduce many aspects of medieval hydroclimate found in paleo-proxy records for much of the Western Hemisphere, northern Eurasia, and the northern tropics. These results suggest that many features of global medieval hydroclimate changes can be explained by changes in tropical Pacific SSTs, though the potential role for other oceans is also discussed

Some Examples of the Applications of the Transonic and Supersonic Area Rules to the Prediction of Wave Drag

The experimental wave drags of bodies and wing-body combinations over a wide range of Mach numbers are compared with the computed drags utilizing a 24-term Fourier series application of the supersonic area rule and with the results of equivalent-body tests. The results indicate that the equivalent-body technique provides a good method for predicting the wave drag of certain wing-body combinations at and below a Mach number of 1. At Mach numbers greater than 1, the equivalent-body wave drags can be misleading. The wave drags computed using the supersonic area rule are shown to be in best agreement with the experimental results for configurations employing the thinnest wings. The wave drags for the bodies of revolution presented in this report are predicted to a greater degree of accuracy by using the frontal projections of oblique areas than by using normal areas. A rapid method of computing wing area distributions and area-distribution slopes is given in an appendix

Key habitat features facilitate the presence of Barred Owls in developed landscapes

As urbanization continues to transform landscapes, it is imperative to find ways to conserve biodiversity within fragmented habitats. Forest interior dwelling birds are particularly vulnerable to development pressures because they require large tracts of forest to support their life cycles. Although Barred Owls (Strix varia) are frequently described as an obligate mature forest species, they have been found in urbanized landscapes. To determine if certain habitat characteristics, such as mature trees, facilitate the presence of Barred Owls in developed regions, we modeled Barred Owl occupancy probability along a development gradient in the Piedmont region of the southeastern United States. We surveyed for owls by broadcasting conspecific calls to solicit response and by passively recording at survey sites using autonomous recording units. Detection/nondetection data were collected during the breeding season and analyzed within an occupancy framework to investigate patterns of habitat association in our region, while allowing for imperfect detection of owls. Average tree height was the best predictor of Barred Owl occupancy across a development gradient, regardless of forest coverage. We did not find Barred Owl occupancy to decline with increasing impervious surface density. Our research implies that developed landscapes containing mature urban trees can support breeding populations of Barred Owls