The NSF/RANN FY 1975 program for geothermal resources research and technology

The specific goal of the NSF geothermal program is the rapid development by industry of the nation's geothermal resources that can be demonstrated to be commercially, environmentally and socially acceptable as alternate energy sources. NSF, as the lead agency for the federal geothermal energy research program, is expediting a program which encompasses the objectives necessary for significant utilization. These include: acceleration of exploration and assessment methods to identify commercial geothermal resources; development of innovative and improved technology to achieve economic feasibility; evaluation of policy options to resolve environmental, legal, and institutional problems; and support of experimental research facilities for each type of geothermal resource. Specific projects in each of these four objective areas are part of the NSF program for fiscal year 1975

Josephson tunneling of dark solitons in a double-well potential

We study the dynamics of matter waves in an effectively one-dimensional Bose-Einstein condensate in a double well potential. We consider in particular the case when one of the double wells confines excited states. Similarly to the known ground state oscillations, the states can tunnel between the wells experiencing the physics known for electrons in a Josephson junction, or be self-trapped. As the existence of dark solitons in a harmonic trap are continuations of such non-ground state excitations, one can view the Josephson-like oscillations as tunnelings of dark solitons. Numerical existence and stability analysis based on the full equation is performed, where it is shown that such tunneling can be stable. Through a numerical path following method, unstable tunneling is also obtained in different parameter regions. A coupled-mode system is derived and compared to the numerical observations. Regions of (in)stability of Josephson tunneling are discussed and highlighted. Finally, we outline an experimental scheme designed to explore such dark soliton dynamics in the laboratory.Comment: submitte

A thermal vacuum test optimization procedure

An analytical model was developed that can be used to establish certain parameters of a thermal vacuum environmental test program based on an optimization of program costs. This model is in the form of a computer program that interacts with a user insofar as the input of certain parameters. The program provides the user a list of pertinent information regarding an optimized test program and graphs of some of the parameters. The model is a first attempt in this area and includes numerous simplifications. The model appears useful as a general guide and provides a way for extrapolating past performance to future missions

When two elephants fight, it is the grass that is trampled: A practical theological elucidation of the predatory attitude of hate speech

This study addresses a topic that is often neglected by faith communities, like the proverbial expression ‘an elephant in the room’, namely, hate speech. A community of believers could easily be guilty of practices of hate speech by keeping themselves silent or not being mindful in the way they talk about people. What is more is that the saying ‘when two elephants fight, it is the grass that is trampled’ represents something of the dynamics around this issue in reminding people of the harmful consequences of hate speech for people in close proximity to people who are guilty of hate speech. This article argues that a greater awareness of the intrinsic aspects involved in hate speech is needed before one could even mention the issue of combating it. The predatory attitude that underlies hate speech is examined from a practical theological vantage point. The functioning of attitudes, inner speech, attributes and silence are elucidated. The research question therefore asks whether the silence of faith communities on the predatory nature of hate speech in the public sphere contributes to the fact that people are unaware of their own attributional biases. These biases consequently gather momentum and are voiced as hate speech. This research offers analytical perspectives from the viewpoint of ethics, social psychology and communication sciences to indicate the value of speaking truth in love. Perspectives on the concept of boldness, speaking truth in love and the attitude of like-mindedness with Christ are also offered. After this hermeneutical consideration, the article concludes with practical theological perspectives on how hate speech could be addressed

Resensie die reis gaan inwaarts- Die kuns van sterwe in kreatiewe werke van Karel Schoeman

WEPENER, C. (Bloemfontein: SUN MeDIA, 2017). 233 pp., Prys: R325 (druk), R260 (digitaal), ISBN 978-1-928355-14-4 (druk), ISBN 978-1-928355-15-1 (digitaal

Participation in Christ’s body and his blood during celebration of Holy Communion as illuminated by the meaningful lenses of cognition and recognition

In this article, the author focusses on the importance and possible value of the concepts of cognition and recognition for reflection on what should actually happen during celebration of Holy Communion. The point of departure is that celebration, in essence, means that it should be a meaningful experience. The meaningfulness consists of the intriguing fact that participants are participating in Christ’s body and in his blood while celebrating Holy Communion. In celebrating Holy Communion, people are engaging in a ritual that involves interaction with a variety of symbols. The author offers perspectives based on a qualitative empirical study in which people expressed their views on what they actually experience when celebrating the sacrament of Holy Communion. The article adheres to Browning’s methodological insights. He describes research activity as ranging from description, to systemising (exploring practical wisdom and understanding), to strategising (practising strategic practical theology). The research problem is as follows: ‘Could cognisance of the lenses of cognition and recognition of the deeper message of Holy Communion enrich the conscious appropriation of salvation while celebrating the sacrament of Holy Communion?’ The research problem is addressed from the vantage point of understanding sacraments from a Reformed perspective. The concepts of cognition and recognition are highlighted in a brief historical description of what a sacrament is, taking into account the insights from social psychology regarding the essence of the concepts of cognition and recognition. The author further elaborates on the functioning of the concepts of cognition (phronesis) and recognition (anamnesis). In the last section of the article, the author utilises a hermeneutical interaction between descriptive and systemising perspectives to formulate strategies for how people’s experiences of participation in Holy Communion can be enriched through the meaningful lenses of cognition and recognition

Differences between bone mineral density, lean and fat mass of HIV-positive and HIV-negative black women

Objectives: To investigate the differences between bone mineral density (BMD), lean and fat mass of human immunodeficiency virus (HIV-) positive and HIV-negative black women and to investigate factors associated with low BMD.Methods: Case-control study of black women (n = 565) aged 29–65 years from Potchefstroom, North West province, South Africa, based on secondary analysis of data. Total BMD, left femur neck of the hip (LFN BMD), spine BMD, total fat, fat-free tissue mass and percentage body fat (%BF) were measured by dual-energy X-ray absorptiometry.Results: HIV-negative women had significantly higher median BMD, %BF, appendicular skeletal mass (ASM), ASM index, body mass index (BMI) and waist circumference than HIV-positive women. When the groups were matched for age and BMI, only spine BMD was marginally lower in HIV-positive women. In the total group, age, smoking and HIV status were associated with lower BMD, while calcium intake was positively associated with BMD. Similar variables were associated with BMD in HIV-negative women, while age and educational status were associated with BMD in HIV-positive women.Conclusion: Low BMD was more common among HIV-positive than HIV-negative women. Older HIV-positive women with low educational status are particularly at risk