The theory of hybrid stochastic algorithms (open access)

The theory of hybrid stochastic algorithms

These lectures introduce the family of Hybrid Stochastic Algorithms for performing Monte Carlo calculations in Quantum Field Theory. After explaining the basic concepts of Monte Carlo integration we discuss the properties of Markov processes and one particularly useful example of them: the Metropolis algorithm. Building upon this framework we consider the Hybrid and Langevin algorithms from the viewpoint that they are approximate versions of the Hybrid Monte Carlo method; and thus we are led to consider Molecular Dynamics using the Leapfrog algorithm. The lectures conclude by reviewing recent progress in these areas, explaining higher-order integration schemes, the asymptotic large-volume behaviour of the various algorithms, and some simple exact results obtained by applying them to free field theory. It is attempted throughout to give simple yet correct proofs of the various results encountered. 38 refs.
Date: November 21, 1989
Creator: Kennedy, A.D. (Florida State Univ., Tallahassee, FL (USA). Supercomputer Computations Research Inst.)
Object Type: Article
System: The UNT Digital Library
Relief valve sizing for the sup 3 He recirculation system of the MP-9 polarized target (open access)

Relief valve sizing for the sup 3 He recirculation system of the MP-9 polarized target

This report contains pressure safety analyses for the relief valving of the {sup 3}He pump system, as distinct from the dilution refrigerator (DR). However, in a few instances it has been convenient to include here some aspects of the interaction between the DR and the gas loop proper. The more localized safety aspects of certain elements of the DR, such as the vacuum jacket and window, the Still, and the Phase Separator, will be addressed in a separate analysis.
Date: August 21, 1989
Creator: Hill, D.
Object Type: Report
System: The UNT Digital Library
Aspects of the Kalina technology applied to geothermal power production (open access)

Aspects of the Kalina technology applied to geothermal power production

This report contains the results of studies conducted at the Idaho National Engineering Laboratory (INEL) concerning the applicability of the Kalina technology to geothermal (hydrothermal) power production. This report represents a correction and addition to that report. The Heat Cycle Research Program (HCRP) has as its primary goal the cost-effective production of electric power from moderate temperature hydrothermal resources. Recent work has included the study of supercritical cycles with counterflow condensation which utilize mixtures as working fluids. These advanced concepts are projected to give a 20 to 30% improvement in power produced per unit geofluid flow rate (geofluid effectiveness, w hr/lb). The original Kalina cycle is a system which is similar to the cycles being studied in the Heat Cycle Research program and it was felt that this new cycle should be studied in the geothermal context. 15 refs., 9 figs., 2 tabs.
Date: September 21, 1989
Creator: Bliem, C.J.
Object Type: Report
System: The UNT Digital Library
Hydrothermal pretreatment of coal (open access)

Hydrothermal pretreatment of coal

We have examined changes in Argonne Premium samples of Wyodak coal following 30 min treatment in liquid water at autogenous pressures at 150{degrees}, 250{degrees}, and 350{degrees}C. In most runs the coal was initially dried at 60{degrees}C/1 torr/20 hr. The changes were monitored by pyrolysis field ionization mass spectrometry (py-FIMS) operating at 2.5{degrees}C/min from ambient to 500{degrees}C. We recorded the volatility patterns of the coal tars evolved over that temperature range, and in all cases the tar yields were 25%--30% of the starting coal on mass basis. There was essentially no change after the 150{degrees}C treatment. Small increases in volatility were seen following the 250{degrees}C treatment, but major effects were seen in the 350{degrees} work. The tar quantity remained unchanged; however, the volatility increased so the temperature of half volatility for the as-received coal of 400{degrees}C was reduced to 340{degrees}C. Control runs with no water showed some thermal effect, but the net effect from the presence of liquid water was clearly evident. The composition was unchanged after the 150{degrees} and 250{degrees}C treatments, but the 350{degrees} treatment brought about a 30% loss of oxygen. The change corresponded to loss of the elements of water, although loss of OH'' seemed to fit the …
Date: December 21, 1989
Creator: Ross, David S.
Object Type: Report
System: The UNT Digital Library
An update on standards for radiation in the environment and associated estimates of risk (open access)

An update on standards for radiation in the environment and associated estimates of risk

This presentation reviews current and proposed standards, recommendations, and guidances for limiting routine radiation exposures of the public, and estimates the risk corresponding to standards, recommendations, and guidances. These estimates provide a common basis for comparing different criteria for limiting public exposures to radiation, as well as hazardous chemicals.
Date: June 21, 1989
Creator: Kocher, David C.
Object Type: Article
System: The UNT Digital Library
International Impacts of Global Climate Change: Testimony to House Appropriations Subcommittee on Foreign Operations, Export Financing and Related Programs (open access)

International Impacts of Global Climate Change: Testimony to House Appropriations Subcommittee on Foreign Operations, Export Financing and Related Programs

International impacts of global climate change are those for which the important consequences arise because of national sovereignty. Such impacts could be of two types: (1) migrations across national borders of people, of resources (such as agricultural productivity, or surface water, or natural ecosystems), of effluents, or of patterns of commerce; and (2) changes to the way nations use and manage their resources, particularly fossil fuels and forests, as a consequence of international concern over the global climate. Actions by a few resource-dominant nations may affect the fate of all. These two types of international impacts raise complex equity issues because one nation may perceive itself as gaining at the expense of its neighbors, or it may perceive itself as a victim of the actions of others. 11 refs., 2 figs., 1 tab.
Date: February 21, 1989
Creator: Fulkerson, W.; Cushman, R.M.; Marland, G. & Rayner, S.
Object Type: Report
System: The UNT Digital Library
A measurement of muon fluences associated with the Fermilab Proton Center charged hyperon beam (open access)

A measurement of muon fluences associated with the Fermilab Proton Center charged hyperon beam

The Fermilab Proton Center (PC) hyperon beam was commissioned in the spring of 1980 and first used by E497 to measure charged hyperon fluxes, polarization and magnetic moments. It has subsequently been used for a number of other experiments requiring beams of charged and neutral hyperons, neutral kaons and neutrons. However, a systematic measurement of muon fluence associated with the beam particles has not been done. This note describes an attempt to do so during the recent run of E756 in the winter of 1987/88. These measurements were done parasitically to the E756 running so that the choice of targets or beam conditions was not always optimal for a systematic study. It is hoped that these measurements will be useful in the estimation of backgrounds for PC experiments as well as for the design of future hyperon beams.
Date: February 21, 1989
Creator: Lach, J. & Shan, L. Y.
Object Type: Report
System: The UNT Digital Library
The Role of Geothermal Energy in Minimizing Global Environmental Problems (open access)

The Role of Geothermal Energy in Minimizing Global Environmental Problems

In the 1970's, the nation's attention was focused on Energy. This focus shifted to the Economy in the 80's with the concerns about the federal deficit. Emphasis has now moved to the Environment for the 1990's with the other two ''E's'' remaining as lingering concerns. Obviously geothermal resources have positive impacts on the three E's since they provide energy with limited environmental impact. However, they all are aware of the environmental concerns and must address them for the industry. Two current global environmental concerns discussed in this paper are the ''greenhouse effect'' and acid rain. Both of these areas have been emphasized by President Bush, and legislation is pending in both state and federal legislatures to address these problems. They need to understand the impact of geothermal energy production in these areas, and from a DOE viewpoint, identify R and D that is critical to meeting existing and pending regulations and laws.
Date: March 21, 1989
Creator: Traeger, Richard K.
Object Type: Article
System: The UNT Digital Library
Materials Advances to Enhance Development of Geothermal Power (open access)

Materials Advances to Enhance Development of Geothermal Power

In order to assure the continued development of geothermal resources, many advances in materials technology are required so that high costs resulting from the severe environments encountered during drilling, well completion and energy extraction can be reduced. These needs will become more acute as higher temperature and chemically aggressive fluids are encountered. High priority needs are for lost circulation control and lightweight well completion materials, and tools such as drill pipe protectors, rotating head seals, blow-out preventers, and downhole drill motors. The lack of suitable hydrolytically stable chemical systems that can bond previously developed elastomers to metal reinforcement is a critical but as yet unaddressed impediment to the development of these tools. In addition, the availability of low cost corrosion and scale-resistant tubular lining materials would greatly enhance transport and energy extraction processes utilizing hypersaline brines. Work to address these materials needs is underway at Brookhaven National Laboratory (BNL), and recent accomplishments are summarized in the paper.
Date: March 21, 1989
Creator: Kukacka, Lawrence E.
Object Type: Article
System: The UNT Digital Library
Properties of Geopressured Brines and Wells in the Gulf Coast and Opportunities for Industrial/Research Participation (open access)

Properties of Geopressured Brines and Wells in the Gulf Coast and Opportunities for Industrial/Research Participation

Geopressured reservoirs exhibit pressure gradients in excess of the normal hydrostatic gradient. In the Gulf Coast area the normal gradient is 0.465 psi/ft. Pressures may approach lithostatic pressure and have been measured as high as 1.05 psi/ft in the Gulf Coast area. Geopressured basins exist worldwide and in a number of U.S. locations, east, west, north and south. The Gulf Coast area has been studied extensively and is the subject of the DOE geopressured-geothermal research at present. The assumed ranges in resource characteristics include: depth from -12,000 to > -20,000 feet, brine flow rate from 20,000 to 40,000 bpd, temperature from 300 to 400 F, bottomhole pressure from 12,000 to 18,500 psi; salinity from 20,000 to 200,000 mg/L, gas-water ratio from 40 to 80 scf/bbl., and condensate from a trace to production. Energy in the geopressured resource includes gas, thermal, and hydraulic energy. It has been estimated that there are 6,000 quads of methane and 11,000 quads of thermal energy in the Gulf Coast area geopressured-geothermal reservoirs. Estimates run as high as 50,000 quad for the thermal energy (Wallace et al, 1978). Present industrial interest in the Pleasant Bayou and Hulin wells includes: desalination plants, an economic study by a …
Date: March 21, 1989
Creator: Wys, J. Nequs- de
Object Type: Article
System: The UNT Digital Library
An Overview of Recent Logging Research at The University of Texas Petroleum Engineering Department (open access)

An Overview of Recent Logging Research at The University of Texas Petroleum Engineering Department

Logging research at The University of Texas has been carried out in several areas. We have studied how rock resistivity varies with water saturation when other variables, such as rock wettability, stress, saturation history, and shale content are varied. Both experimental and theoretical work have been done. Rock wettability (oil or water wet) has by far the largest effect. Shale content and saturation history are also important. Rock stress is the least important, at least in the Berea sandstones and glass bed packs we have studied. We have published several papers and theses which describe this work in detail. We have also studied the effect of certain trace elements (boron, mainly) on the neutron log. Boron has a very high thermal neutron capture cross Section. Analyses of a number of Frio formation cores from the Texas Gulf Coast area show that boron occurs frequently in these rocks in amounts (up to 100 ppm or more) that would seriously affect several procedures in neutron log interpretation. It could, for example, reduce or even eliminate the neutron log--density log porosity reversal that is commonly used as a gas indicator. A recent paper reports details of our work in the Frio. We are …
Date: March 21, 1989
Creator: Dunlap, H. F.
Object Type: Article
System: The UNT Digital Library
Materials Advances to Enhance Development of Geothermal Power (open access)

Materials Advances to Enhance Development of Geothermal Power

None
Date: March 21, 1989
Creator: Kukacka, Lawrence E.
Object Type: Article
System: The UNT Digital Library
Magma Energy Overview and Status Report (open access)

Magma Energy Overview and Status Report

Up to 500,000 Quads of thermal energy are believed to be contained in crustal magma bodies within the U.S. at temperatures in excess of 600 C and at depths less than 10 km. Scientific feasibility of utilizing this energy resource was concluded after a seven-year study that culminated in successful energy extraction experiments in molten rock at Kilauea Iki lava lake. The current DOE program is developing technology to experimentally extract energy from a silicic magma body so that engineering feasibility of the magma energy concept can be evaluated. At this point, significant progress has been achieved in three areas: Geophysics and site selection. Energy Extraction Processes, and Geochemistry/Materials. Future activities will be focused by drilling and evaluating a deep exploratory well in Long Valley caldera where active magma is expected.
Date: March 21, 1989
Creator: Dunn, James C.
Object Type: Article
System: The UNT Digital Library
Developments in Geothermal Waste Treatment Biotechnology (open access)

Developments in Geothermal Waste Treatment Biotechnology

Extensive laboratory studies have indicated that the application of biochemical processes in the development of biotechnology suitable for conversion of geothermal wastes from hazardous to non-hazardous materials is technically and economically feasible. These studies have also shown that such biotechnology may require bioreactors capable of handling different amounts and types of residual sludges. Particular attention has to be paid to the duration of treatment, efficiency of cycling, and maintenance of biomass. Laboratory studies addressing these parameters are described.
Date: March 21, 1989
Creator: Premuzic, Eugene T. & Lin, Mow S.
Object Type: Article
System: The UNT Digital Library
Comments on Reservoir Technology, DOE PR VII, San Francisco, March 23, 1989 (open access)

Comments on Reservoir Technology, DOE PR VII, San Francisco, March 23, 1989

My assignment is to give feedback on the Reservoir Technology Task portion of the DOE-sponsored work we've been hearing about. Briefly, you've done well in adapting to an increasingly tough budgetary and political environment. More specifically, I'd like to highlight some of the encouraging developments in the context of overall research strategy. Ted Mock on Tuesday and Ken Nemzer at yesterday's luncheon made several useful observations and I'd like to refer to just two in relation to Reservoir Technology. Ted observed that product development can proceed along two paths. We might call these the Big Bang or the Evolutionary lines. He correctly pointed out the difficulty American industry has had with commercializing incremental (Evolutionary) product improvements. In this context Reservoir Technology development is more like manufacturing engineering because we aren't developing new products, for the most part. We are simply working to produce electricity or process heat cheaper. The DOE has listened to industry on this point and their statement of objectives sounds excellent. Let me quote one example from Page 10 of the December 20, 1988 report. For ''Reservoir Evaluation'' we read ''Decrease uncertainties...20% by 1993''. I confess that I don't know what the uncertainty is in 1989, but …
Date: March 21, 1989
Creator: Barker, B.J.
Object Type: Article
System: The UNT Digital Library
The Development of the Geopressured Resource: A Status Report (open access)

The Development of the Geopressured Resource: A Status Report

As a response to the America's need for alternate energy sources, the US Department of Energy has a Geothermal Program. Within this program is a category to study Geopressured Energy. Today many activities are taking place under the Geopressured Program. These activities for the most part fall under one of the following categories: Well Operations, Geoscience and Engineering Support and Energy Conversion. To date this program has had many successes. However, there is still more information needed concerning the Geopressured Resource. it is thought that continued research will give the developer a better understanding of the Geopressured resource and in turn increase the likelihood of it's development.
Date: March 21, 1989
Creator: Taylor, Kenneth J.
Object Type: Article
System: The UNT Digital Library
DOE Research and Development for the Geothermal Marketplace (open access)

DOE Research and Development for the Geothermal Marketplace

This audience is well aware that the major goal of all geothermal R&D is the successful application of advanced technology in the marketplace. In support of that goal, the Geothermal Technology Division has forged a close link between its research objectives and potentially competitive market applications. Our technical objectives are all expressed in quantified reductions in the cost of geothermal power; these cost reductions are the force that will drive the geothermal industry for the foreseeable future. I agree with the recent statement of Stephen Fye of Unocal that without a legislated incentive for geothermal or disincentive for competing fuels-such as mandated carbon dioxide reductions--any premium the public is willing to pay for the use of this premium fuel will be too small to greatly impact geothermal economics. His conclusion is that the geothermal industry must be fully competitive in the marketplace at current prices. His further conclusion--with which I fully concur--is that the avenue to competitiveness is through research, by both industry and government.
Date: March 21, 1989
Creator: Mock, John E.
Object Type: Article
System: The UNT Digital Library
Critique of "Fluid Production" R&D for Geothermal Program Review VII (open access)

Critique of "Fluid Production" R&D for Geothermal Program Review VII

The stated goal of Geothermal Technology Division (GTD's) research program is to provide technical solutions required to establish all forms of this resource as long-term competitive energy alternatives. Especially at a time when the research budget is relatively small and competitive energy alternatives are relatively cheap, the emphasis on achieving tangible economic benefits through research is appropriate. In the case of a new technology such as tapping magma energy, it is too early to fine-tune the economics, but the research is well-justified by the magnitude of the potential resource. For projects aimed at incremental improvements in processes that are already commercial, economic potential is more easily defined. Fluid production research generally falls in the latter category. In keeping with the foregoing, it would be desirable for the research program participants to place greater emphasis on the potential applications and economic impact of their respective projects. Specifically, with regard to research projects aimed at improving the economics of existing commercial operations, the following points should be addressed: (1) in what resources, or types of resources, would the research results be applicable; (2) what are the best commercially available materials or techniques available, and how will the results of research improve operations …
Date: March 21, 1989
Creator: Verity, Robert V.
Object Type: Article
System: The UNT Digital Library
An Organized Effort to Develop the Hydrothermal Energy Resource (open access)

An Organized Effort to Develop the Hydrothermal Energy Resource

As a response to America's need for Alternate Energy sources, the U.S. Department of Energy has a Geothermal Program. Within this program is a Hydrothermal category. Currently, a wide range of tasks are being addressed as part of the Hydrothermal Program. The tasks include Industrialization, Reservoir Technology, Hard Rock Penetration and Conversion Technology. It is thought that successes already made in this program combined with upcoming successes will increase the likelihood of geothermal energy becoming a contributor to our nations future energy needs.
Date: March 21, 1989
Creator: Taylor, Kenneth J.
Object Type: Article
System: The UNT Digital Library
Geothermal Field Case Studies that Document the Usefulness of Models in Predicting Reservoir and Well Behavior (open access)

Geothermal Field Case Studies that Document the Usefulness of Models in Predicting Reservoir and Well Behavior

The geothermal industry has shown significant interest in case histories that document field production histories and demonstrate the techniques which work best in the characterization and evaluation of geothermal systems. In response to this interest, LBL has devoted a significant part of its geothermal program to the compilation and analysis of data from US and foreign fields (e.g., East Mesa, The Geysers, Susanville, and Long Valley in California; Klamath Fall in Oregon; Valles Caldera, New Mexico; Cerro Prieto and Los Azufres in Mexico; Krafla and Nesjavellir in Iceland; Larderello in Italy; Olkaria in Kenya). In each of these case studies we have been able to test and validate in the field, or against field data, the methodology and instrumentation developed under the Reservoir Technology Task of the DOE Geothermal Program, and to add to the understanding of the characteristics and processes occurring in geothermal reservoirs. Case study results of the producing Cerro Prieto and Olkaria geothermal fields are discussed in this paper. These examples were chosen because they illustrate the value of conceptual and numerical models to predict changes in reservoir conditions, reservoir processes, and well performance that accompany field exploitation, as well as to reduce the costs associated with …
Date: March 21, 1989
Creator: Lippmann, Marcelo J.
Object Type: Article
System: The UNT Digital Library
Technology Transfer and the Product Development Process (open access)

Technology Transfer and the Product Development Process

It is my pleasure this morning to address a topic that is much talked about in passing but rarely examined from a first person point of view. That topic is Technology Transfer. Over the next 30 minutes I'd like to approach Technology Transfer within the context of the Product Development Process looking at it from the perspectives of the federal government researcher and the industry manufacturer/user. Fist let us recognize that we are living in an ''Information Age'', where global economic and military competition is determined as much by technology as it is by natural resource assets. It is estimated that technical/scientific information is presently growing at a rate of l3 percent per year; this is expected to increase to 30 percent per year by the turn of the century. In fact, something like 90 percent of all scientific knowledge has been generated in the last 30 years; this pool will double again in the next 10-15 years (Exhibit 1). Of all the scientists and engineers throughout history, 90% live and work in the present time. Successfully managing this technical information/knowledge--i.e., transforming the results of R&D to practical applications--will be an important measure of national strength. A little over a …
Date: March 21, 1989
Creator: Mock, John E.
Object Type: Article
System: The UNT Digital Library
Optimization of Injection Scheduling in Geothermal Fields (open access)

Optimization of Injection Scheduling in Geothermal Fields

This study discusses the application of algorithms developed in Operations Research to the optimization of brine reinjection in geothermal fields. The injection optimization problem is broken into two sub-problems: (1) choosing a configuration of injectors from an existing set of wells, and (2) allocating a total specified injection rate among chosen injectors. The allocation problem is solved first. The reservoir is idealized as a network of channels or arcs directly connecting each pair of wells in the field. Each arc in the network is considered to have some potential for thermal breakthrough. This potential is quantified by an arc-specific breakthrough index, b{sub ij}, based on user-specified parameters from tracer tests, field geometry, and operating considerations. The sum of b{sub ij}-values for all arcs is defined as the fieldwide breakthrough index, B. Injection is optimized by choosing injection wells and rates so as to minimize B subject to constraints on the number of injectors and the total amount of fluid to be produced and reinjected. The use of the various methods is demonstrated with reference both to hypothetical data and an actual data set from the Wairakei Geothermal Field in New Zealand.
Date: March 21, 1989
Creator: Lovekin, James & Horne, Roland N.
Object Type: Article
System: The UNT Digital Library
Hot Dry Rock Geothermal Reservoir Model Development at Los Alamos (open access)

Hot Dry Rock Geothermal Reservoir Model Development at Los Alamos

Discrete fracture and continuum models are being developed to simulate Hot Dry Rock (HDR) geothermal reservoirs. The discrete fracture model is a two-dimensional steady state simulator of fluid flow and tracer transport in a fracture network which is generated from assumed statistical properties of the fractures. The model's strength lies in its ability to compute the steady state pressure drop and tracer response in a realistic network of interconnected fractures. The continuum approach models fracture behavior by treating permeability and porosity as functions of temperature and effective stress. With this model it is practical to model transient behavior as well as the coupled processes of fluid flow, heat transfer, and stress effects in a three-dimensional system. The model capabilities being developed will also have applications in conventional geothermal systems undergoing reinjection and in fractured geothermal reservoirs in general.
Date: March 21, 1989
Creator: Robinson, Bruce A. & Birdsell, Stephen A.
Object Type: Article
System: The UNT Digital Library
Geothermal Prospects in a Shrinking Power Surplus (open access)

Geothermal Prospects in a Shrinking Power Surplus

The western power surplus is finite and electric load growth is persistent. Concerns about availability and environmental effects will overshadow life-cycle cost in selection of tomorrow's sources. Geothermal's growth and achievements qualify it as a preferred resource for the 1990s and beyond but its merits remain largely unknown in political and financial circles. Near-term needs include power sales contracts after 1990, improved comfort for banks and utilities with reservoir assessment techniques and mitigation of financial risks at pilot plants on new fields. Institutional, not technical, issues will dominate geothermal energy's growth, performance, image and utility relationships in the 1990s.
Date: March 21, 1989
Creator: Geyer, John D.
Object Type: Article
System: The UNT Digital Library