Search

The requirements, design, and verification and validation of the software used in the FEHM application, a finite-element heat- and mass-transfer computer code that can simulate nonisothermal multiphase multicomponent flow in porous media, are described. The test of the DOE Code Comparison Project, Problem Five, Case A, which verifies that FEHM has correctly implemented heat and mass transfer and phase partitioning, is also covered.

The user`s manual documents the use of the Yucca Mountain Site Characterization Projects Finite element heat and mass transfer code (FEHMN) application. The manual covers: Program considerations, data files, input data, output, system interface, and examples.

This models and methods summary provides a detailed description of the mathematical models and numerical methods employed by the finite element heat and mass tranfer code (FEHMN) application.

This report presents the mathematical bases for measuring internal temperatures within batch and flowing systems using chemically reacting tracers. This approach can obtain temperature profiles of plug-flow systems and temperature histories within batch systems. The differential equations for reactant conversion can be converted into Fredholm integral equations of the first kind. The experimental variable is the tracer-reaction activation energy. When more than one tracer is used, the reactions must have different activation energies to gain information. In systems with temperature extrema, multiple solutions for the temperature profiles or histories can exist, When a single parameter in the temperature distribution is needed, a single-tracer test may furnish this information. For multi-reaction tracer tests, three Fredholm equations are developed. Effects of tracer-reaction activation energy, number of tracers used, and error in the data are evaluated. The methods can determine temperature histories and profiles for many existing systems, and can be a basis for analysis of the more complicated dispersed-flow systems. An alternative to using the Fredholm-equation approach is the use of an assumed temperature- distribution function and incorporation of this function into the basic integral equation describing tracer behavior. The function contains adjustable parameters which are optimized to give the temperature distribution.more » The iterative Fredholm equation method is tested to see what is required to discriminate between two models of the temperature behavior of Hot Dry Rock (HDR) geothermal reservoirs. Experimentally, ester and amide hydrolyses are valid HDR tracer reactions for measuring temperatures in the range 75-100{degrees}C. Hydrolyses of bromobenzene derivatives are valid HDR tracer reactions for measuring temperatures in the range 150-275{degrees}C.« less

The Office of Technology Development (OTD) in the Department of Energy`s (DOE) Office of Environmental Restoration and Waste Management is investigating new technologies for ``better, faster, cheaper, safer`` environmental remediation. A program at DOE`s Savannah River site was designed to demonstrate innovative technologies for the remediation of volatile organic compounds (VOCs) at nonarid sites. Two remediation technologies, in situ air stripping and in situ bioremediation--both using horizontal wells, were demonstrated at the site between 1990--1993. This brief report summarizes the conclusions from three separate modeling studies on the performance of these technologies.

Neptunium has a high solubility in groundwaters from Yucca Mountain [1]. Uranium in nuclear reactors produces 237Np which has a half-life of 2.14 × 106 years. Consequently, the transport of 237Np through tuffs is of major importance in assessing the performance of a high-level nuclear waste repository at Yucca Mountain. The objective of this work is to determine the amount of Np retardation that is provided by the minerals in Yucca Mountain tuffs as a function of groundwater chemistry.

A fracture network model has been developed to simulate transient fluid flow behavior in a fractured rock mass. Included is a pressure-dependent aperture submodel to simulate behavior often seen in fractured systems. The model is used to simulate data from the Fenton Hill Hot Dry Rock (HDR) geothermal reservoir. Both low-pressure/low-flow-rate and high-pressure/high-flow-rate transient data are adequately simulated. The model parameters obtained suggest ways in which the model can be refined to achieve even more realistic fits to the data. The model is then used to demonstrate more efficient operating modes than the two-well circulating mode usually proposed for HDR reservoirs. 11 refs., 9 figs., 1 tab.

OBJECTIVE To assess the influence of human immunodeficiency virus (HIV) infection on pregnancy outcome and the effect of pregnancy on the short-term course of HIV infection. METHODS Pregnant women with identified risk factors for HIV infection but without AIDS were tested serologically for HIV antibodies. Seropositive women were compared to seronegative patients with similar risk factors and demographic characteristics at enrollment, at delivery, and 6-8 weeks postpartum. One hundred one seropositive and 97 seronegative subjects were evaluated for symptoms or physical manifestations of HIV infection; evidence of immune dysfunction; historical, physical, or laboratory evidence of related infections; and maternal and neonatal outcome. Both groups were compared to the entire obstetric population delivering at the University of Maryland Hospital during 1 year. RESULTS There was a significant reduction in reported risk behaviors in both groups during pregnancy as compared to the period before pregnancy (P < .001). The majority of women in both groups were asymptomatic, but seropositive women were more likely to have a history or physical evidence of condylomata (13 versus 4%; P < .05) and higher temperatures on admission to the labor suite (98.6 +/- 1.0 versus 98.3 +/- 0.8F; P = .02). Seropositive women were not at greater risk for antepartum medical complications. Only one woman developed an AIDS-defining opportunistic infection. Although hematologic indices in seropositive women were abnormal, these did not progress over the course of pregnancy. At delivery, seropositive women were more likely to receive antibiotics (25 versus 10%; P = .006) and less likely to have an episiotomy (25 versus 40%; P = .03), but obstetric outcome was unaffected. Neonatal status was independent of antibody status. CONCLUSION Our findings support a growing body of evidence that pregnancy has no discernible effect on the early progression of HIV disease in asymptomatic women, and infection does not influence perinatal outcome.

Field testing of a hydraulically stimulated, hot dry rock (HDR) geothermal system at the Fenton Hill site in northern New Mexico indicated that significant reservoir growth occurred as energy was extracted. Tracer, microseismic, and geochemical measurements provided the primary quantitative evidence for the increases in accessible reservoir volume and fractured rock surface area that were observed during energy extraction operations that caused substantial thermal drawdown in portions of the reservoir. These temporal increases suggest that augmentation of reservoir hear-production capacity in an HDR system may be possible. [DJE 2005]

The paper will examine the examples of Arethusa and Kyane, two springs situated in Syracusan territory that knew some fame in antiquity. According to legend, the first one, Arethusa, a nymph in the retinue of Artemis, was a Peloponnesian native who crossed the seas to escape the Olympian Alpheius River’s lust. Once aground on Ortygia, later the heart of the Corinthian colony of Syracuse, she was transformed into a spring by her patron goddess, and the river who followed her poured its waters into her streams, establishing an eternal link between the Greek motherland, and Sicily, land of Greek diaspora. For her part, Kyane was a native nymph who witnessed the abduction or rape of Kore by the god Hades, who punished her by changing her into a spring. Both were integrated into Greek cultural and religious heritage and have thus crossed the boundaries of their adopted island. As early as the end of the 6th century BCE, Arethusa is frequently mentioned in ancient literature, from Pindar, probably the first author to name her, down to Imperial Latin writers, and even their Byzantine successors. She is one of the most popular figures of ancient literature regarding nymphs. As both springs were undoubtedly places of worship, they were both instruments of fertility of the land and of Syracusan women. The paper will highlight the material and symbolic role they play in Syracusan culture, and in relationships between motherland and colony, as well as the Hellenic koine., L'article propose d’examiner les exemples d’Aréthuse et de Cyané, deux sources du territoire syracusain qui ont connu une certaine gloire dans le monde antique. Selon la légende, la première, Aréthuse, nymphe d’Artémis, originaire du Péloponnèse, aurait traversé les mers pour échapper à la fougue du fleuve olympien Alphée. Une fois sur le sol d’Ortygie, au coeur de la fondation corinthienne, elle aurait été métamorphosée en source par sa patronne, et le fleuve l’aurait suivie et aurait uni ses eaux aux siennes, instaurant ainsi un lien éternel entre le Péloponnèse, patrie du dieu des dieux et la Sicile, terre de diaspora grecque. Par opposition, Cyané est une nymphe autochtone qui se serait opposée à Hadès lors du rapt de Koré et que le dieu aurait transformée en source pour la punir. Ces deux sources ont la particularité d’avoir été intégrées dans le patrimoine mythique de la culture grecque et d’avoir ainsi dépassé les frontières de leur île d’adoption. Dès la fin du vie s. av. J.-C. Aréthuse est évoquée abondamment par les sources textuelles, depuis Pindare, premier auteur, semble-t-il, à l’avoir mentionnée, jusqu’aux sources latines impériales tardives, voire byzantines. Elle est l’une des nymphes les plus populaires de la tradition grecque. Sur la source Cyané, Diodore de Sicile atteste des sacrifices très anciens, qui dateraient de la venue d’Héraclès en Sicile. Lieux probables de culte, ces sources sont également des instruments de la fertilité territoriale et de la fécondité féminine de l’apoikia corinthienne. On cherchera à mettre en exergue le rôle symbolique qu’elles ont joué toutes les deux, à la fois dans la culture syracusaine, dans les liens de syngénéia entre la métropole et la colonie, ainsi que dans la koinè panhellénique.

International audience

International audience

International audience

International audience