135 research outputs found

    Alaska mining and water quality

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    The Institute of Water Resources has sought financial assistance for some time in an attempt to initiate research relative to the impact of mining on water quality. Attempts were made as early as 1971 by Dr. Timothy Tilsworth and later by Dr. Donald Cook and Dr. Sage Murphy. These investigators anticipated growth in placer gold mining and the development of natural resources in Alaska during a period of national and environmental concern. The subsequent energy "crisis," the major increase in the price of gold on the world market, and dwindling nonrenewable resource supplies have resulted in large-scale mineral exploration in Alaska. This exploration, coupled with development of the trans-Alaska oil pipeline, has attracted considerable capital for potential investment and development in Alaska. Expected industrial growth has already started and major new projects are "just around the corner." Yet, as of 1976, no major research effort has occurred to determine the extent of or potential for water quality impacts from mining operations in Alaska. Recently a series of interdisciplinary research projects have been completed in Canada; however, the application of Canadian data to Alaskan problems is uncertain. Although, state and federal government agencies have been advised and are aware of this potential problem and lack of baseline data they have not sought out new information or rational solutions. Even now, with deadlines of Public Law 92-500 at hand, some regulatory agencies give the impression of attempting to ignore the situation. Interim limitations are proposed and permits are issued with no discernible rationale or basis. Data have not been obtained relative to the Alaskan mining operations and thus are not available for use in seeking solutions compatible with mining and environmental protection. Numbers appear to have been arbitrarily assigned to permits and water quality standards. When permits are issued, self-monitoring requirements are negligible or nonexistent. Nor have regulatory agencies demonstrated the ability or inclination to monitor mining operations or enforce permits and water quality standards. It was hoped that the project would bring together miners, environmentalists, and regulators in a cooperative effort to identify the problems and seek solutions. The investigators recognized the political sensitivity of the subject matter but proceeded optimistically. Relatively good cooperation, though not total, occurred early in the project. In April 1976, a symposium was held to exchange ideas and determine the state-of-the-art. Although the symposium had good attendance and an exchange of information occurred, the symposium itself was somewhat of a disappointment. With few exceptions, the participants aligned on one side or the other in preconceived fixed positions. Some even chose not to attend and were therefore able to avoid the issues. Little hard data was presented. Optimistically, some of the miners, environmentalists, and regulators are prepared to resolve their differences. This report, hopefully, will be of benefit to them. It is our experience that miners and environmentalists share a love of the land that is uniquely Alaska. We feel that technology is available for application to this problem for those who care about doing the job right in the "last frontier." Whether or not it will be effectively applied to protect Alaska's water resources is a question which remains unanswered.The work upon which this report is based was supported in part by funds provided by the United States Department of the Interior, Office of Water Resources Research Act of 1964, Public Law 88-379, as amended (Project A-055-ALAS)

    Cold climate water/wastewater transportation and treatment - a bibliography: completion report

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    This bibliography contains 1,400 citations, including published and unpublished papers, on cold-climate water and wastewater transportation and treatment systems. Sources listed include state and federal agency files which contain information on systems in Alaskan communities and the Alyeska Pipeline Service Company camps. References to systems in other northern countries are also included. The objectives of this study were to identify causes of the failure of Alaskan water and wastewater treatment and transportation facilities and to seek methods for design improvements. Originally, the investigators contemplated an evaluation of systems performance in remote areas in relation to the original conception, planning, design, and construction. Because of the tremendous amount of literature examined, the evaluation was undertaken in a subsequent study, "Alaska Wastewater Treatment Technology" (A-058-ALAS) by Dr. Ronald A. Johnson.OWRT AGREEMENT NO. 14-31-0001-5002 PROJECT NO. A-047-ALAS The work upon which this completion report is based was supported by funds provided by the U. S. Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1964, Public Law 88-379, as amended

    Thermodynamic Entropy And The Accessible States of Some Simple Systems

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    Comparison of the thermodynamic entropy with Boltzmann's principle shows that under conditions of constant volume the total number of arrangements in simple thermodynamic systems with temperature-independent heat capacities is TC/k. A physical interpretation of this function is given for three such systems; an ideal monatomic gas, an ideal gas of diatomic molecules with rotational motion, and a solid in the Dulong-Petit limit of high temperature. T1/2 emerges as a natural measure of the number of accessible states for a single particle in one dimension. Extension to N particles in three dimensions leads to TC/k as the total number of possible arrangements or microstates. The different microstates of the system are thus shown a posteriori to be equally probable, with probability T-C/k, which implies that for the purposes of counting states the particles of the gas are distinguishable. The most probable energy state of the system is determined by the degeneracy of the microstates.Comment: 9 pages, 1 figur

    Critical behavior of Born Infeld AdS black holes in higher dimensions

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    Based on a canonical framework, we investigate the critical behavior of Born-Infeld AdS black holes in higher dimensions. As a special case, considering the appropriate limit, we also analyze the critical phenomena for Reissner Nordstrom AdS black holes. The critical points are marked by the divergences in the heat capacity at constant charge. The static critical exponents associated with various thermodynamic entities are computed and shown to satisfy the thermodynamic scaling laws. These scaling laws have also been found to be compatible with the static scaling hypothesis. Furthermore, we show that the values of these exponents are universal and do not depend on the spatial dimensionality of the AdS space. We also provide a suggestive way to calculate the critical exponents associated with the spatial correlation which satisfy the scaling laws of second kind.Comment: LaTex, 22 pages, 12 figures, minor modifications in text, To appear in Phys. Rev.

    Ehrenfest's scheme and thermodynamic geometry in Born-Infeld AdS black holes

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    In this paper we analyze the phase transition phenomena in Born-Infeld AdS black holes using Ehrenfest's scheme of standard thermodynamics. The critical points are marked by the divergences in the heat capacity. In order to investigate the nature of the phase transition, we analytically check both the Ehrenfest's equations near the critical points. Our analysis reveals that this is indeed a second order phase transition. Finally, we analyze the nature of the phase transition using state space geometry approach. This is found to be compatible with the Ehrenfest's scheme.Comment: Published versio

    Effective thermodynamics of strongly coupled qubits

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    Interactions between a quantum system and its environment at low temperatures can lead to violations of thermal laws for the system. The source of these violations is the entanglement between system and environment, which prevents the system from entering into a thermal state. On the other hand, for two-state systems, we show that one can define an effective temperature, placing the system into a `pseudo-thermal' state where effective thermal laws are upheld. We then numerically explore these assertions for an n-state system inspired by the spin-boson environment.Comment: 9 pages, 3 figure

    Simulational nanoengineering: Molecular dynamics implementation of an atomistic Stirling engine

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    A nanoscale-sized Stirling engine with an atomistic working fluid has been modeled using molecular dynamics simulation. The design includes heat exchangers based on thermostats, pistons attached to a flywheel under load, and a regenerator. Key aspects of the behavior, including the time-dependent flows, are described. The model is shown to be capable of stable operation while producing net work at a moderate level of efficiency.Comment: 4 pages, 8 figures (minor changes

    Carnot cycle for an oscillator

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    Carnot established in 1824 that the efficiency of cyclic engines operating between a hot bath at absolute temperature ThotT_{hot} and a bath at a lower temperature TcoldT_{cold} cannot exceed 1Tcold/Thot1-T_{cold}/T_{hot}. We show that linear oscillators alternately in contact with hot and cold baths obey this principle in the quantum as well as in the classical regime. The expression of the work performed is derived from a simple prescription. Reversible and non-reversible cycles are illustrated. The paper begins with historical considerations and is essentially self-contained.Comment: 19 pages, 3 figures, sumitted to European Journal of Physics Changed content: Fluctuations are considere

    Ideal gas sources for the Lemaitre-Tolman-Bondi metrics

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    New exact solutions emerge by replacing the dust source of the Lem\^aitre-Tolman-Bondi metrics with a viscous fluid satisfying the monatomic gas equation of state. The solutions have a consistent thermodynamical interpretation. The most general transport equation of Extended Irreversible Thermodynamics is satisfied, with phenomenological coefficients bearing a close resemblance to those characterizing a non relativistic Maxwell-Bolzmann gas.Comment: 7 pages, Plain TeX with IOP macros, important corrections to previous version, 3 figures (to appear in Classical and Quantum Gravity, June 1998

    Thermodynamics of phase transition in higher dimensional AdS black holes

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    We investigate the thermodynamics of phase transition for (n+1) (n+1) dimensional Reissner Nordstrom (RN)-AdS black holes using a grand canonical ensemble. This phase transition is characterized by a discontinuity in specific heat. The phase transition occurs from a lower mass black hole with negative specific heat to a higher mass black hole with positive specific heat. By exploring Ehrenfest's scheme we show that this is a second order phase transition. Explicit expressions for the critical temperature and critical mass are derived. In appropriate limits the results for (n+1) (n+1) dimensional Schwarzschild AdS black holes are obtained.Comment: LaTex, 11 pages, 5 figures, To appear in JHE
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