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Artificial geothermal reservoirs in hot volcanic rock

Description: S>Some recent results from the Los Alamos program in which hydraulic fracturing is used for the recovery of geothermal energy are discussed. The location is about 4 kilometers west and south of the ring fault of the enormous Jemez Caldera in the northcentral part of New Mexico. It is shown that geothermal energy may be extracted from hot rock that does not contain circulating hot water or steam and is relatively impermeable. A fluid is pumped at high pressure into an isolated section of a wellb… more
Date: February 8, 1974
Creator: Aamodt, R. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hot dry rock geothermal reservoir engineering

Description: Two wells, GT-2 and EE-1, were originally drilled to a depth of 9600 ft (2.93 km) and 10,000 ft (3.05 km), respectively, and, after some difficulties, including redrilling of the bottom portion of GT-2, a good fracture connection was made between EE-1 and GT-2B, as the modified GT-2 was called. The circulation system was studied extensively for the purpose of establishing a number of fracture properties. Techniques were developed to determine orientation, geometry, heat exchange area, volume, f… more
Date: January 1, 1980
Creator: Aamodt, R. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

Description: This report develops a broad review and assessment of quantitative modeling approaches and data requirements for large-scale subsurface flow in radioactive waste geologic repository. The data review includes discussions of controlled field experiments, existing contamination sites, and site-specific hydrogeologic conditions at Yucca Mountain. Local-scale constitutive models for the unsaturated hydrodynamic properties of geologic media are analyzed, with particular emphasis on the effect of stru… more
Date: August 1, 1991
Creator: Ababou, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Unstable crack motion is predictable

Description: Yoffe's linear theory of dynamic brittle fracture suggests that crack motion will be unstable beyond {approx}70% of the Rayleigh speed, a prediction that is not supported by experiment. We show by atomistic simulations that hyperelasticity, the elasticity of large strains, plays a governing role in the instability dynamics of brittle fracture. A simple scaling model based on an effective elastic modulus, coupled with Yoffe's solution, gives successful predictions for the onset speed of the crac… more
Date: August 22, 2004
Creator: Abraham, F
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ADVANCED COMPOSITE WIND TURBINE BLADE DESIGN BASED ON DURABILITY AND DAMAGE TOLERANCE

Description: The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a … more
Date: February 16, 2012
Creator: Abumeri, Galib & Abdi, Frank
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fractal analysis of pressure transients in the Geysers Geothermal Field

Description: The conventionally accepted models for the interpretation of pressure transient tests in naturally fractured reservoirs usually involve simplistic assumptions regarding the geometry and transport properties of the fractured medium. Many single well tests in this type of reservoirs fail to show the predicted behavior for dual or triple porosity or permeability systems and cannot be explained by these models. This paper describes the application of a new model based on a fractal interpretation of… more
Date: January 1, 1992
Creator: Acuna, J.A.; Ershaghi, I. & Yortsos, Y.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Stress trajectory and advanced hydraulic-fracture simulations for the Eastern Gas Shales Project. Final report, April 30, 1981-July 30, 1983

Description: A summary review of hydraulic fracture modeling is given. Advanced hydraulic fracture model formulations and simulation, using the finite element method, are presented. The numerical examples include the determination of fracture width, height, length, and stress intensity factors with the effects of frac fluid properties, layered strata, in situ stresses, and joints. Future model extensions are also recommended. 66 references, 23 figures.
Date: January 1, 1983
Creator: Advani, S. H. & Lee, J. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of characteristic time concepts for hydraulic fracture configuration design, control, and optimization

Description: The analysis of pertinent energy components or affiliated characteristic times for hydraulic stimulation processes serves as an effective tool for fracture configuration designs optimization, and control. This evaluation, in conjunction with parametric sensitivity studies, provides a rational base for quantifying dominant process mechanisms and the roles of specified reservoir properties relative to controllable hydraulic fracture variables for a wide spectrum of treatment scenarios. Results ar… more
Date: October 1, 1992
Creator: Advani, S. H.; Lee, T. S. & Moon, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of characteristic time concepts for hydraulic fracture configuration design, control, and optimization. Final report

Description: The analysis of pertinent energy components or affiliated characteristic times for hydraulic stimulation processes serves as an effective tool for fracture configuration designs optimization, and control. This evaluation, in conjunction with parametric sensitivity studies, provides a rational base for quantifying dominant process mechanisms and the roles of specified reservoir properties relative to controllable hydraulic fracture variables for a wide spectrum of treatment scenarios. Results ar… more
Date: October 1, 1992
Creator: Advani, S. H.; Lee, T. S. & Moon, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Fracture, Aging and Disease in Bone

Description: From a public health perspective, developing a detailed mechanistic understanding of the well-known increase in fracture risk of human bone with age is essential. This also represents a challenge from materials science and fracture mechanics viewpoints. Bone has a complex, hierarchical structure with characteristic features ranging from nanometer to macroscopic dimensions; it is therefore significantly more complex than most engineering materials. Nevertheless, by examining the micro-/nano-stru… more
Date: February 1, 2006
Creator: Ager, Joel; Balooch, G. & Ritchie, R. O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Aging and Fracture of Human Cortical Bone and Tooth Dentin

Description: Mineralized tissues, such as bone and tooth dentin, serve as structural materials in the human body and, as such, have evolved to resist fracture. In assessing their quantitative fracture resistance or toughness, it is important to distinguish between intrinsic toughening mechanisms which function ahead of the crack tip, such as plasticity in metals, and extrinsic mechanisms which function primarily behind the tip, such as crack bridging in ceramics. Bone and dentin derive their resistance to f… more
Date: May 7, 2008
Creator: Ager, Joel; Koester, Kurt J.; Ager, Joel W., III & Ritchie, Robert O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Discrete-event simulation of nuclear-waste transport in geologic sites subject to disruptive events. Final report

Description: This report outlines a methodology to study the effects of disruptive events on nuclear waste material in stable geologic sites. The methodology is based upon developing a discrete events model that can be simulated on the computer. This methodology allows a natural development of simulation models that use computer resources in an efficient manner. Accurate modeling in this area depends in large part upon accurate modeling of ion transport behavior in the storage media. Unfortunately, developm… more
Date: June 19, 1980
Creator: Aggarwal, S.; Ryland, S. & Peck, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calibrated Properties Model

Description: The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the ''AMR Development Plan for U0035 Calibrated Properties Model REV00. These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepa… more
Date: March 12, 2000
Creator: Ahlers, C. & Liu, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Testing and modeling of seepage into underground openings in aheterogeneous fracture system at Yucca Mountain, Nevada

Description: We discuss field activities designed to characterize seepage into an underground opening at the potential site for geologic storage of high-level radioactive waste (HLRW) at Yucca Mountain, Nevada, and the use of these data for development and calibration of a model for predicting seepage into planned HLRW emplacement drifts. Air-injection tests were conducted to characterize the permeability of the fractured rock, and liquid-release tests (LRTs) were conducted and seepage monitored to characte… more
Date: March 25, 2002
Creator: Ahlers, C. F.; Trautz, R. C.; Cook, P. J. & Finsterle, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Impact of Rock Bolts on Seepage

Description: Characterization of seepage into drifts in unsaturated fractured tuff is a key factor for assessing the long-term viability of the proposed high level nuclear waste repository at Yucca Mountain. Rock bolts are among the methods proposed for ground control in the emplacement drifts. They may provide a conduit whereby percolating water that would otherwise bypass the drift will seep into the drift. The objective of this study is to assess the impact that the use of rock bolts may have on seepage.… more
Date: June 1, 2001
Creator: Ahlers, F. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Intermediate-field transport of contaminants

Description: This report is about intermediate-field'' transport or the migration of contaminants from arrays of discrete waste packages or sources. In constructing nuclear waste repositories in rock, it may be necessary to place a waste package across a rock fracture, or a rock fracture may develop some time after waste packages have been emplaced. To predict the spatial and temporal distribution of contaminant species from a line of waste packages facing a rock fracture may be important, because such frac… more
Date: June 1, 1989
Creator: Ahn, J. (Tokyo Univ. (Japan)); Kim, C. L. (Korea Advanced Energy Research Inst., Seoul (Republic of Korea)); Chambre, P. L.; Pigford, T. H. & Lee, W. W. L. (California Univ., Berkeley, CA (USA). Dept. of Nuclear Engineering Lawrence Berkeley Lab., CA (USA))
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Nuclide migration through a planar fissure with matrix diffusion

Description: This report presents the first results of a new analytical study of the hydrological transport of a radioactive contaminant through a planar fracture in porous rock. The purpose is to predict the space-time dependent concentration of the contaminant in the groundwater, as affected by advective transport within the fracture and by molecular diffusion of the contaminant into and out of pores that intersect the fracture surfaces.
Date: April 1, 1985
Creator: Ahn, J.; Chambre, P. L. & Pigford, T. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Radionuclide migration through fractured rock: Effects of multiple fractures and two-member decay chains

Description: This report presents the results of an analytical study of the hydrological transport of a radioactive contaminant through fractured, porous rock. The purpose is to evaluate the time-, and space-dependent concentration of the contaminant in the ground-water in the fractures and in the rock pores. We propose a simplified analytical method that superposes two single-fracture solutions for the concentration in the rock matrix with a system of parallel fractures. The exact solutions require multipl… more
Date: September 1, 1985
Creator: Ahn, J.; Chambre, P. L. & Pigford, T. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Transient of diffusion from a waste solid into fractured porous rock

Description: Previous analytical studies of the advective transport of dissolved contaminants through fractured rock have emphasized the effect of molecular diffusion in the rock matrix in affecting the space-time-dependent concentration of the contaminant as it moves along the fracture. Matrix diffusion only in the direction normal to the fracture surface was assumed. Contaminant sources were constant-concentration surfaces of width equal to the fracture aperture and of finite or infinite extent in the tra… more
Date: January 1, 1988
Creator: Ahn, J.; Chambre, P. L. & Pigford, T. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Nuclide migration from areal sources into a fracture

Description: This document shows analytic solutions to the problem of hydrogeologic transport of radionuclides released from finite areal sources into a planar fracture. It illustrates the solutions through numerical and graphical displays of the spatial and temporal distribution of the radionuclides as a result of advection in the fracture, transverse dispersion and surface sorption, as well as diffusion into and sorption in the rock matrix. The numerical illustrations indicate that sufficient distances aw… more
Date: April 1, 1987
Creator: Ahn, J.; Chambre, P. L.; Pigford, T. H. & Lee, W. W. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Radionuclide dispersion from multiple patch sources into a rock fracture

Description: This report presents results of an analytical study on hydrological transport of a radionuclide released from sources of finite areal extent into a planar fracture. The purposes of this work are to predict the space-time-dependent concentrations of a radionuclide which is released from multiple-patch (or area) sources and transported by advection and transverse dispersion in a planar fracture and by molecular diffusion in rock matrix, and to investigate the effects of transverse dispersion in t… more
Date: September 1, 1986
Creator: Ahn, J.; Chambre, P. L.; Pigford, T. H. & Lee, W. W. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Transient Diffusion From a Waste Solid Into Water-Saturated, Fractured Porous Rock

Description: Numerical illustrations for transient mass transfer from an infinitely long cylinder intersected by a planar fracture are shown based on Chambre's exact analytical solutions. The concentration at the cylinder surface is maintained at the solubility. In the fracture contaminant diffuses in the radial direction. In the rock matrix three-dimensional diffusion is assumed in the cylindrical coordinate. No advection is assumed. Radioactive decay and sorption equilibrium are included. Radioactive deca… more
Date: September 1989
Creator: Ahn, J.; Chambre, P. L.; Pigford, T. H. & Lee, W. W. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Mass transfer and transport of radionuclides in fractured porous rock

Description: Analytical studies are made to predict space-time dependent concentrations of radionuclides transported through water-saturated fractured porous rock. A basic model, which is expected to generate conservative results when used in long-term safety assessment of geologic repositories for radioactive waste, is established. Applicability and limitations of the model are investigated. 67 refs., 54 figs., 3 tabs.
Date: April 1, 1988
Creator: Ahn, Joonhong
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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