Electromagnetic (EM) logging provides an efficient method for high-resolution, vertical delineation of electrically conductive contamination in glacial sand-and-gravel aquifers. EM, gamma, and lithologic logs and spec...
Electromagnetic (EM) logging provides an efficient method for high-resolution, vertical delineation of electrically conductive contamination in glacial sand-and-gravel aquifers. EM, gamma, and lithologic logs and specific conductance data from sand-and-gravel aquifers at five sites in the northeastern United States were analyzed to define the relation of EM conductivity to aquifer lithology and water quality. Municipal waste disposal, septic waste discharge, or highway deicing salt application at these sites has caused contaminant plumes in which the dissolved solids concentration and specific conductance of ground water exceed background levels by as much as 10 to 20 times. The major hydrogeologic factors that affected EM log response at the five sites were the dissolved solids concentration of the ground water and the silt and clay content in the aquifer. EM conductivity of sand and gravel with uncontaminated water ranged from less than 5 to about 10 millisiemens per meter (mS/m);that of silt and clay zones ranged from about 15 to 45 mS/m;and that of the more highly contaminated zones in sand and gravel ranged from about 10 to more than 80 mS/m. Specific conductance of water samples from screened intervals in sand and gravel at selected monitoring well installations was significantly correlated with EM conductivity. EM logging can be used in glacial sand-and-gravel aquifer investigations to (1) determine optimum depths for the placement of monitoring well screens;(2) provide a nearly continuous vertical profile of specific conductance to complement depth-specific water quality samples;and (3) identify temporal changes in water quality through sequential logging. detailed lithologic or gamma logs, preferably both, need to be collected along with the EM logs to define zones in which elevated EM conductivity is caused by the presence of silt and clay beds rather than contamination.
作者:
RAINS, dAMITCHELL, KADr. Dean A. Rains:is president of Decision Engineering
Pascagoula Miss. He has been an active member of ASNE since 1970 a frequent contributor to the Naval Engineers Journal and a participant at ASNE Day as an author and a discusser. He was either chairman or paper chairman for several Cruiser Destroyer and Frigate Technology Symposiums held in Biloxi Miss. He is past chairman of the Pascagoula Section of ASNE. He is currently the program chairman for the Pascagoula Section. He has forty-two years engineering experience and is a graduate of the California Institute of Technology from which he received his B.S. M.S. and Ph.D. all in mechanical engineering. Kenneth A. Mitchell
Jr.:is an engineer with U.S. Marine New Orleans La. He was formerly an engineer at Decision Engineering Pascagoula Miss. and has three years of engineering experience. He is an active member of ASNE. Mr. Mitchell received his B.S. in naval architecture and marine engineering from the University of New Orleans.
The budget cuts of the 1990s have placed the Navy in a difficult position when trying to maintain neet levels capable of meeting a more dispersed and less defined threat. The cancellation of Seawolf initiated a large ...
The budget cuts of the 1990s have placed the Navy in a difficult position when trying to maintain neet levels capable of meeting a more dispersed and less defined threat. The cancellation of Seawolf initiated a large effort to define a suhmarine that is capable and affordable with today's shrinking budget. Manv European countries have turned to air independent (AIP), non-nuclear propulsion systems as a way of increasing the effectiveness of their fleets when compared to their current diesel/electric bouts. Bv evaluating and comparing two AIP and one hybrid propulsion systems to current nuclear capabilities, we can help define options for the next generation submarine. This paper attempts to provide design and cost information which can be used in conjunction with mission profiles to determine the best system for the desired job. Tomorrow's submarine will perform a variety of missions. Most all can be handled well bv nuclear submarines, but at what cost? These performance/cost tradeoffs are the subject of this paper.
This article examines the relationship of the purchasing anddesign functions in the U.K. defense industry. In particular, it focuses on the role of purchasing and its potential input into the design process. Perhaps ...
作者:
dURANT, NdMYERS, VBECCLES, LA
Washington D.C. 20460) has worked as an environmental scientist in the RCRA corrective action program at EPA since 1989. After graduating from Colgate University in 1987 Durant worked for GeoTrans Inc. conducting hydrogeologic investigations at numerous waste disposal sites throughout the northeastern United States. At present Durant is pursuing an M.S. degree in environmental science from The Johns Hopkins University. His research is focused on enhancing in situ biodegradation of aromatic organic compounds in the subsurface.
Washington D. C. 20460) graduated from The Johns Hopkins University in 1972 with a B.A. degree in natural sciences. Myers received a Ph.D. in oceanography from Florida State University in 1977. During 1978 he held a post doctoral fellowship at University of Florida in the Department of Environmental Engineering and Science. From 1979 to 1983 Myers was employed by the Florida Department of Environmental Regulation where he worked on environmental restoration projects. Since 1984 Myers has worked at EPA managing RCRA ground water monitoring and corrective action programs. Lawrence A. Eccles (U.S. Environmental Protection Agency
Environmental Monitoring Systems Laboratory P.O. Box 93478 Las Vegas NV 89193–3478) is a hydrologist with the EPA Environmental Monitoring Systems Research Laboratory in Las Vegas Nevada. Eccles is responsible for the development of vadose zone and in situ monitoring techniques and guidelines. After graduating from Monmouth College with a B.S. degree in chemistry Eccles performed graduate work in chemical engineering at New Mexico State University. He received formal training in hydrology in 1969 from the U.S. Geological Survey in Denver and worked with that agency before joining EPA at Las Vegas in 1984. One of his co-authored articles was chosen for the Best Paper Award by the journal Ground Water in 1975 and another was the subject of a cover story for Water Well Journal in 1977.
The U.S. Environmental Protection Agency (EPA) recently proposed to amend federal regulations to require vadose zone monitoring at certain hazardous waste facilities. To support this proposal, EPA evaluated previous p...
The U.S. Environmental Protection Agency (EPA) recently proposed to amend federal regulations to require vadose zone monitoring at certain hazardous waste facilities. To support this proposal, EPA evaluated previous policy on vadose zone monitoring and examined advances in vadose zone monitoring technology. Changes in EPA vadose zone monitoring policy were driven by demonstrated advances in the available monitoring technology and improvements in understanding of vadose zone processes. When used under the appropriate conditions, currently available direct and indirect monitoring methods can effectively detect contamination that may leak from hazardous waste facilities into the vadose zone. direct techniques examined include soil-core monitoring and soil-pore liquid monitoring. Indirect techniques examined include soil-gas monitoring, neutron moderation, complex resistivity, ground-penetrating radar, and electrical resistivity. Properly designed vadose zone monitoring networks can act as a complement to saturated zone monitoring networks at numerous hazardous waste facilities. At certain facilities, particularly those in arid climates where the saturated zone is relatively deep, effective vadose zone monitoring may allow a reduction in the scope of saturated zone monitoring programs.
Power System Stabilizers (PSS) superimposed to the basic control system of an HVdC link supplying a weak AC system, in order to enhance its frequency regulation action, are proposed. To decrease the AC voltage sensiti...
Researchers at Texas A&M Universitv have studied the effects of battle damage on ship power distribution cables, with particular interest in damaged cables which did not fail immediately. The electrical signatures...
Researchers at Texas A&M Universitv have studied the effects of battle damage on ship power distribution cables, with particular interest in damaged cables which did not fail immediately. The electrical signatures of partiallv damaged cables are significant and are detectable with advanced protection methods used on terrestrial power svstems. Findings show that the damaged cable signatures are similar to those of arcing faults on terrestrial power distribution svstems, which can be reliably detected using an on-line expert svstem [1,2,3]. The implications of these findings are significant. Since the abilitv of a damaged ship to right through an encounter is entirelv dependent on keeping operational its various systems which rely on electric power, the ability to automatically detect and re-route power arounddamaged regions is imperative. By identifving the characteristics of failing power cables before catastrophic failure occurs, the protection process can be integrated into the ship automatic control system. The overall result is a more survivable ship.
Several future Navy combat systems under development require efficient delivery of high power microwave energy from remote transmitters to array antennas. To achieve this requirement, a family of microwave components ...
Several future Navy combat systems under development require efficient delivery of high power microwave energy from remote transmitters to array antennas. To achieve this requirement, a family of microwave components has been developed and tested. Progress is described in the design and testing of an overmoded circular TE01 mode waveguide applicable to special shipboard needs. Because such a waveguide had originally been developed for low power millimeter band trunkline communications between cities, new theoretical, design, and fabrication techniques had to be developed to meet our specific performance requirements. Moreover, in order to fulfill the combat system requirements, the waveguide would have to withstand harsh military requirements. Over several years the obstacles to the application of overmodedtechnology to Navy combat systems have been systematically eliminated. The effort has resulted in the invention of several new components, the development and validation of a new computer aideddesign package, and the implementation of new microwave measurement techniques. The first application of an overmoded waveguide to a combat system element was recently achieved in the successful demonstration of the prototype Cooperative Engagement Capability, and steps toward a production military version of the waveguide have been initiated.
As technology advances and our dependency on software increases, the requirement to develop the correct means to improve quality in both the deveiopment phase and the maintenance phase of software life cycle support b...
As technology advances and our dependency on software increases, the requirement to develop the correct means to improve quality in both the deveiopment phase and the maintenance phase of software life cycle support becomes increasingly significant. The focus of this paper is on the dilemma facing software engineering in maintaining quality within the constraints of the maintenance phase. The paper further proposes that the software maintenance process can also be analvzed and improved using statistical process control (SPC) techniques. The methods discussed in this paper have been proposed for use in the Software Maintenance project at NUWC detachment Norfolk. Upon successful testing at NUWC detachment Norfolk, they will be forwarded to the AN/SQQ-89(V) (interagencv) Software Quality Evaluation Committee for use by other agencies which are developing and maintaining AN/SQQ-89(V) software.
作者:
Gubanski, S.M.Wang, M.‐S.E.Dr. Stanislaw Gubanski (1950) received his M.Sc. (High-Voltage Engineering) and Ph.D. (Materials Science) degrees from the Technical University of Wroclaw/Poland in 1973 and 1976
respectively. He has worked as a research fellow at the University College of North Wales at Bangor/UK and then as a senior lecturer at the Technical University of Wroclaw/Poland. In the meantime he spent two years at the Federal University of Technology Bauchi/Nigeria and also worked as a guest researcher at the Chalmers University of Technology Göteborg/Sweden. At present he is Associate Professor at the Department of Electrical Plant Engineering of Royal Institute of Technology at Stockholm/Sweden. His major field of interest includes aging processes in electrical insulation and their diagnostics. (Royal Institute of Technology Department of Electrical Plant Engineering S-10044 Stockholm/Sweden T +468/790 7775 Fax +468/2052 68) Dr. Min-Sheng Edward Wang (1964) is agraduate of Xi'an Jiaotong University/China (B.Sc 1984. M.Eng. 1987
D.Eng. 1991) in Electricai Engineering. He worked as a research engineer in the National Key Laboratory of Electrical Insulation in China from 1987 to 1991 and also as a guest researcher at the Electrical Power Research Centre at the Royal Institute of Technology at Stockholm/Sweden 1991 to 1992. He is currently a post-doc research fellow involved in the field of conducting polymers at the Institute Physics and Chemistry of Silo Carlos University of São Paulo/Brazil. His research interests mainly focus on the influences of structure and morphology on the electrical properties of polymeric dielectrics. (University of São Paulo Instititue of Physics and Chemistry Dept. of Physics and Materials Science Av. Dr. Carlos Botelho 1465 BR-13560 São Paulo/Brazil T +551 62/71 53 65 Fax +551 62/71 36 16)
Thermally Stimulateddepolarization (TSd) current spectra and surface wettabilities, represented by contact angles, i. e. the advancing angle and the receding angle, were measured on two types of high voltage room tem...
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