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THE MAINTENANCE REQUIREMENTS SYSTEM - RISK-BASED RESOURCE programMING AT WORK

NAVAL ENGINEERS JOURNAL 1994年第3期106卷 279-284页

作者： JACOBS, KS SODERSTROM, GW Kenneth S. Jacobs:is the director of the Naval Sea Systems Command's Surface Ship Maintenance Division. Originally trained as a data systems technician he attended Old Dominion University in Norfolk Virginia graduating with a BS degree in mechanical engineering in 1975. Over the course of the last eighteen years Mr. Jacobs has served in NavSea as a project engineer for boats and service craft as the type desk for AFS AOR AO and AOG ship types and as manager of the Amphibious and Auxiliary Ship Maintenance Strategy Program where he was instrumental in the development and implementation of the Phased Maintenance Program. He has authored several papers on the subject of ship maintenance and is a member of Tau Beta Pi Engineering Honor Society ASNE and the Association of Scientists and Engineers. Grant W. Soderstrom:is an engineer with American Management Systems Inc. He received his BS in Physics from the U.S. Naval Academy in 1983 and his MS in systems engineering from Virginia Polytechnic Institute and State University in 1991. While on active duty he served as weapons officer and in various engineering positions on nuclear submarines qualifying as a naval nuclear engineer. His maintenance experience includes a submarine refueling overhaul. For the past two years he has been involved with surface ship maintenance engineering.

The U.S. Navy has refined its program Objective Memorandum (POM) development process to ensure that future budgets provide adequate ship maintenance funding while maintaining the proper balance between force structure and force readiness. The Maintenance Requirements System (MRS) is now the process which allows the U.S. Navy Surface Ship community to forecast and defend its requirements by articulating the potential mission impact (risk) of funding constraints. Risk is defined across many disciplines as the product of the severity of an outcome and the probability of an outcome. For maintenance, we define relative risk as the severity of system failure times the probability of system failure if a maintenance task is not performed. Any limited budget carries some risk, since some maintenance tasks will not be funded. When funding for a future availability is constrained, MRS sorts the representative maintenance tasks in descending order of risk and cuts the list based on funding. MRS then identifies the mission impact of each unfunded maintenance task. This method does not predict or dictate the actual maintenance performed on each ship in the future, but through feedback it projects the types and costs of required maintenance and provides an estimate of the impact of funding constraints. This paper outlines the basic principles of risk-based decision making, provides a detailed discussion of an actual risk-based decision making process (MRS), and suggests some other maintenance applications of risk-based decision making.

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Lie Group Analysis for a Multispecies, Spatially Inhomogeneous, : Mutually Interacting Gas Mixture

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Transport Theory and Statistical physics 1992年第1-2期21卷 119-131页

作者： Azmy, Y.Y. Boffi, V.C. Mandrekas, J. Protopopescu, V. Azmy, Y.Y. Engineering Physics and Mathematics Division Oak Ridge National Laboratory Oak Ridge TN 31831-6363 United Kingdom University of Rome “La Sapienza” Rome via Eudossiana 18-00184 Italy Fusion Rcsearch Center and Nuclear Engineering Program Georgia Inslitute of Tcclinology Atlanta GA 30332 United States Oak Ridge National Laboratory Oak Ridge Tennessee 37831-6363 P.O. Box 2008Bldg. 6025MS-6363 United Kingdom

We consider systems of general nonlinear PDEs that arise in the extended kinetic theory of gases describing mixtures of spatially inhomogeneous, mutually interacting species. For general, autonomous, space-independent interaction laws, these systems are always invariant under the translation group. Via Lie group analysis methods, we show that for a Lotka-Volterra interaction law and three or more species, the system is invariant under a three-parameter group of transformations representing scaling, and translation in time and space. Moreover, the Lie group analysis shows that this is the only invariance group of the system. Copyright © 1992 by Marcel Dekker, Inc.

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MAGNETOHYDRODYNAMIC SUBMARINE PROPULSION SYSTEMS

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NAVAL ENGINEERS JOURNAL 1991年第3期103卷 141-157页

作者： SWALLOM, DW SADOVNIK, I GIBBS, JS GUROL, H NGUYEN, LV VANDENBERGH, HH Daniel W. Swallomis the director of military power systems at Avco Research Laboratory Inc. a subsidiary of Textron Inc. in Everett Mass. Dr. Swallom received his B.S. M.S. and Ph.D. degrees in mechanical engineering from the University of Iowa Iowa City Iowa in 1969 1970 and 1972 respectively. He has authored numerous papers in the areas of power propulsion and plasma physics and currently is a member of the Aerospace Power Systems Technical Committee of the AIAA. Dr. Swallom has directed various programs for the development of advanced power generation systems lightweight power conditioning systems and advanced propulsion systems for marine applications. His previous experience includes work with Odin International Corporation Maxwell Laboratories Inc. Argonne National Laboratory and the Air Force Aero Propulsion Laboratory. Currently Dr. Swallom is directing the technical efforts to apply magnetohydrodynamic principles to a variety of propulsion and power applications for various marine vehicles and power system requirements respectively. Isaac Sadovnikis a principal research engineer in the Energy Technology Office at Avco Research Laboratory Inc. a subsidiary of Textron Inc. He received his B.S. in engineering (1974) B.S. in physics (1975) M.S. in aeronautics and astronautics (1976) and Ph.D. in physics of fluids (1981) at the Massachusetts Institute of Technology. Dr. Sadovnik has been involved in research work funded by DARPA concerning the use of magnetohydrodynamics for underwater propulsion. He has built theoretical models that predict the hydrodynamic behavior of seawater flow through magnetohydrodynamic ducts and their interaction with the rest of the vehicle (thrust and drag produced). In addition Dr. Sadovnik has been involved in research investigations geared toward the NASP program concerning the use of magnetohydrodynamic combustion-driven accelerator channels. Prior to joining Avco Dr. Sadovnik was a research assistant at MIT where he conducted experimental and

Magnetohydrodynamic propulsion systems for submarines offer several significant advantages over conventional propeller propulsion systems. These advantages include the potential for greater stealth characteristics, increased maneuverability, enhanced survivability, elimination of cavitation limits, greater payload capability, and the addition of a significant emergency propulsion system. These advantages can be obtained with a magnetohydrodynamic propulsion system that is neutrally bouyant and can operate with the existing submarine propulsion system power plant. A thorough investigation of magnetohydrodynamic propulsion systems for submarine applications has been completed. During the investigation, a number of geometric configurations were examined. Each of these configurations and mounting concepts was optimized for maximum performance for a generic attack class submarine. The optimization considered each thruster individually by determining the optimum operating characteristics for each one and accepting only those thrusters that result in a neutrally buoyant propulsion system. The results of this detailed optimization study show that the segmented, annular thruster is the concept with the highest performance levels and greatest efficiency and offers the greatest potential for a practical magnetohydrodynamic propulsion system for attack class submarines. The optimization study results were used to develop a specific point design for a segmented, annular magnetohydrodynamic thruster for an attack class submarine. The design point case has shown that this thruster may be able to provide the necessary thrust to propel an attack class submarine at the required velocity with the potential for a substantial acoustic signature reduction within the constraints of the existing submarine power plant and the maintenance of neutral buoyancy. This innovative magnetohydrodynamic propulsion system offers an approach for submarine propulsion that can be an important contributio

关键词： Ship Propulsion

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Tritium penetration through concrete

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Waste Management 1989年第1期9卷 27-36页

作者： Eichholz, G.G. Park, W.J. Hazin, C.A. Nuclear Engineering and Health Physics Program Georgia Institute of Technology Atlanta GA 30332 United States

Experimental tests have been performed, with tritium as a tracer, on a series of concrete cylinders of a high slag aggregate composition to measure tritium mobility and to determine its dependence on concrete properties and environmental parameters. It was found that uncoated concrete absorbs water quite rapidly and once wetted, conducts tritium in water at a rate of about 8 × 10-4 cm3/cm2 day. For thick specimens, over 10 cm in thickness, tritium movement is solely determined by porosity and hydraulic conductivity. Diffusion rates can be lowered by a surface finish, by using a smaller stone size in the aggregate and by vibratory compaction. Standing water may provide a hydrostatic head that results in some increase in flow rate, but it too is limited by the terminal value in hydraulic conductivity. Unless the concrete wall is coated or impregnated in some permanent fashion, it appears that little credit can be taken for the concrete walls as a retarding barrier for tritium-bearing liquids.

关键词： Radioactive Wastes

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Dose rate effects in the control of iron bacteria by irradiation

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Applied Radiation and Isotopes 1989年第4期40卷 337-339页

作者： Eichholz, G.G. Poppell, S.W. Nuclear Engineering and Health Physics Program Georgia Institute of Technology Atlanta GA 30332 United States

The control of iron-reducing bacteria, such as Pseudonomas, in water intake pipes by irradiation is an attractive alternative to chemical methods. Tests have been conducted with a slow-flowing circulating system to determine the lowest dose-rate that will inhibit bacterial build-up on wire-mesh filters. Dose rates of the order of 2.5 Gy/h seem to be adequate for this purpose, permitting the use of relatively weak sources.

关键词： Microorganisms

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MIGRATION OF ELEMENTAL MERCURY THROUGH SOIL FROM SIMULATED BURIAL SITES

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WATER RESEARCH 1988年第1期22卷 15-20页

作者： EICHHOLZ, GG PETELKA, MF KURY, RL Nuclear Engineering and Health Physics Program Georgia Institute of Technology Atlanta GA 30332 U.S.A.

The potential migration of metallic mercury from shallow land burial sites into groundwater has been investigated by means of laboratory column tests and radioactive tracers. It was found that mercury will dissolve in water on concentrations of 20-80 ppb and high concentrations of EDTA in water will increase mercury solubility by complex formation. Standing mercury was found to penetrate up to 3-4 cm into dry soil columns under its own head. Flow tests with soil-equilibrated water, EDTA solutions or kaolin suspensions all showed little demonstrable migration or entrainment beyond the top 2 cm of the columns.

关键词： mercury waste disposal subsurface water soil migration entrainment radioactive tracers environmental impact mercury analysis

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SPECIFIC ACTIVITY MEASUREMENTS TO DETERMINE PHOSPHORUS TURNOVER IN BLUEGILL, LEPOMIS-MACROCHIRUS

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HYDROBIOLOGIA 1988年第1期157卷 3-11页

作者： KAHN, B TURGEON, KS MARTINI, DK DUNKERLY, SJ ELSHINAWY, RMK WILSON, MD 1.Nuclear Engineering and Health Physics Program School of Mechanical Engineering Georgia Institute of Technology 30332 Atlanta GA USA

The biological turnover constant for phosphorus was determined in muscle and five other sections of bluegill. Bluegill of average weight 121 g were maintained in a large flowthrough system at ***.-***. C and fed worms, Eisenia foetida, at two feeding levels, ad lib. (which averaged 2.6 g/d per 100-g fish, wet weight), and 1.5 g/d per 100-g fish. The daily phosphorus intakes at the two levels per 100-g fish were 3.1 and 1.8 mg. The average phosphorus concentration was 2.4 mg/g in muscle and 15.4 mg/g in the whole fish. Worm food was spiked with P-32 at increasing daily increments to balance radioactive decay. The radioactive worms were fed daily to the bluegill during the P-32 accumulation period of 51 days. For the next 28 days of depuration, nonradioactive worms were fed. Sets of three bluegill were collected at approximately weekly intervals, sectioned and analyzed for P-32 and phosphorus. All data were reported as specific activity in tissue relative to specific activity in feed, with P-32 count rates corrected for its 14.3-day half life. Phosphorus turnover constants were obtained by three approaches: (1) from the relative specific activity measured near steady state;(2) by fitting an equation for a 1-compartment model to the accumulation and depuration data;and (3) by fitting an equation for a simplified 2-compartment model to the depuration data. The biological turnover constant calculated with all three approaches was 0.004 d-1 for phosphorus in muscle of bluegill fed ad lib.

关键词： Phosphorus P-32 bluegill biological turnover constant radioactive tracer study specific activity measurements

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Potential radiation control of biofouling bacteria on intake filters

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International Journal of Radiation Applications and Instrumentation. Part 1988年第1-3期31卷 139-147页

作者： Eichholz, Geoffrey G. Jones, Cynthia G. Haynes, Harold E. Nuclear Engineering and Health Physics Program Georgia Institute of Technology Atlanta GA 30332 United States

The biofouling of filters at deep wells supplying water for industrial and drinking water purposes by various iron- and sulfur-reducing bacteria is a wide-spread problem in the United States and can cause serious economic losses. Among the means of control, steam heating or chemical additives can be applied only intermittently and have their own environmental impact. Preliminary studies have shown that installation of a sealed gamma radiation source may provide an alternative solution. Analysis of a range of water samples from contaminated wells identified many of the samples as rich in barsiderocapsa and barpseudomona bacteria. Static and dynamic experiments on water samples at various does and dose rates have shown that these organisms are relatively radiation-sensitive, with a lethal dose in the range of 200-400Gy (20-40kR). Since the main objective is to restrict growth or deposit of plaque on filters, dose rates of the order of 50-75 Gy/hr would be adequate. Such dose rates could be obtained with relatively weak sources, depending on filter dimensions. A conceptual design for such systems has been proposed. © 1988.

关键词： Bacterial fouling filters radiation control water supplies water treatment

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The Dosimetry of Ionizing Radiation, Volume IIedited by K. R. Kase, B. E. Bjärngard, and F. H. Attix

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Medical physics 1988年第4期15卷 648-648页

作者： Geoffrey G. Eichholz Reviewer Nuclear Engineering and Health Physics Program Georgia Institute of Technology Atlanta Georgia 30332

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EVALUATION OF POTENTIAL RADON EXPOSURE FROM DEVELOPMENT OF GEORGIA PHOSPHATE DEPOSITS.

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Mining engineering 1986年第3期38卷 195-196页

作者： Eichholz, G.G. Ambrose, J.P. Skowroski, M.G. Georgia Inst of Technology Nuclear Engineering & Health Physics Program Atlanta GA USA Georgia Inst of Technology Nuclear Engineering & Health Physics Program Atlanta GA USA

This paper estimates the magnitude of any radon-based health effects that might arise from future mining operations in selected areas of the Georgia coastal region. To do this, a model was developed that took into account the mining operations themselves, the atmospheric dispersion of the radon released, and the radon daughter concentrations in nearby towns. The model was applied to both extremes. The first application was a hypothetical mining operation in Echols County. The second application was a site near Savannah, Georgia.

关键词： PHOSPHATE DEPOSITS

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