Climatic impact of alternative energy sources

Detailed evaluations have suggested that the order of magnitude of energy demand 50 yr from the present will be 25–40 TW compared with about 8 TW at the present day. Three energy supply sources could be developed on a large enough scale to satisfy a demand of this magnitude: solar and nuclear energy and fossil fuels. The potential climate impact of the large-scale deployment of solar energy conversion systems has not been evaluated in detail. Solar thermal electric conversion systems could impact climate through large-scale changes in the energy balance at the earth's surface, in the surface roughness and in the surface wetness. Photovoltaic conversions could impact climate by acting as a local heat source. Ocean thermal electric conversion systems would have their main impact through changes in ocean surface temperature, but could also interfere with major ocean currents and have an impact through release of CO₂ into the atmosphere or albedo changes, for example. The cultivation of plants for biomass conversion systems could influence climate through causing large-scale changes in the surface characteristics. The biomass conversion could also impact climate through releases of gases and particulate matter into the atmosphere. Through the use of climate models and observational studies, these impacts should be studied in more detail. In the meantime, the climate constraint should be kept in mind during the development of energy policy and the policies should be kept flexible at the present time until some of the uncertainties about the climate system have been resolved.     

Coping with the threat of AIDS: An approach to psychosocial assessment.

Discusses research issues associated with the study of the effects of acquired immune deficiency syndrome (AIDS) on the psychosocial welfare of gay males, focusing on 5 areas: obtaining qualitative data, developing inventories, sampling in the gay community, building community networks, and characterizing the crisis of AIDS. Behavioral changes wrought by AIDS in this population are described; most changes have involved the reduction of the number and type of sexual activities. Altered relationships with heterosexuals and problems faced by heterosexual researchers in working with this population are examined. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three-Dimensional Effects for Supported Excavations in Clay

This paper presents the results of 150 finite-element simulations conducted to define the effects of excavation geometry, i.e., length, width, and depth of excavation, wall system stiffness, and factor of safety against basal heave on the three-dimensional ground movements caused by excavation through clays. The results of the analyses are represented by the plane strain ratio (PSR), defined as the maximum movement in the center of an excavation wall computed by three-dimensional analyses normalized by that computed by a plane strain simulation. A simple equation for PSR is presented based on excavation geometry, wall system stiffness, and factor of safety against basal heave. This PSR equation reasonably represents trends in results of the 150 simulations as well as those simulations reported in literature. When the excavated length normalized by the excavated depth of an excavation wall is greater than 6, results of plane strain simulations yield the same displacements in the center of that wall as those computed by a three-dimensional simulation.     

Photoacoustic Spectroscopy for the Study of the Adsorption of Dyes on Wool Fabrics

Dyes have been applied to different wool fabrics and measurements by photoacoustic spectroscopy showed well-defined absorption bands. Differences were found in the spectral properties of dyes, which appeared visually to be very similar, indicating that photoacoustic spectroscopy may be useful for the identification of dyes on wool fabrics. Photoacoustic spectroscopy was also shown to be capable of measuring two-dye and three-dye combinations and very dark colours. Comparisons with reflectance spectroscopy showed that photoacoustic spectroscopy might usefully complement the results obtained from reflectance measurements.     

Contrastive and counterfactual reasoning in causal judgment.

Addressed differences in the use of covariation information implied by counterfactual reasoning, which focuses on the question "Would the event Y have occurred if the candidate X had not?" and contrastive reasoning, which involves comparing the target episode to contrasting background instances and noting distinctive features. Two experiments test hypotheses regarding the use of counterfactual and contrastive thinking under different conditions. Findings suggest that when no candidate has been identified, people are more likely to engage in constrastive thinking, but they may engage in counterfactual thinking when they are asked to evaluate a specific candidate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The new video marketplace and the impending regulatory identity crisis

The emergence of a diverse video marketplace, in which a number of technologies compete with television to deliver entertainment and information to the home has created a regulatory dilemma for the FCC. To a certain extent, the FCC has shown reluctance to depart from the traditional regulatory classification. However, the Commission seems to be moving toward greater licensee autonomy. This approach may, ultimately, be the most effective response to an era of rapid technological change and the regulatory identity crisis.