检索结果-内蒙古大学图书馆

1ST TECHNICAL SYMP ON LUNAR CONCRETE

作者： LIN, TD AHMED, G HILL, G ROBINSON, S LIN, T LINDBERGH, C OGALLAGHER, J (1) Principal Research Engineer Construction Technology Laboratories Inc. Chairman ACI125.(2) Post Doctor Researcher Construction Technology Laboratories.(3) Former Cadets of Civil Engineering and Computer Science Department respectively The Citadel.(4) Graduate Student Ceramic Engineering Department University of Missouri - Rolla(5) Head of Civil Engineering Department The Citadel College(6) Professor Physics Department University of Chicago

ISBN: (纸本)9780870316234

The recently established Lunar/Mars Program Office at Johnson Space Center is studying options that include construction of lunar outposts in the early 21st Century, and subsequent structures for industrial operations. Major industrialization on the Moon cannot occur without an assess to lunar resources. Construction of structures such as large pressurized habitats, launching facilities, lunar surface transportation systems, and liquefied oxygen storage tanks requires enormous volumes of materials. Experiments sponsored by the National Aeronautics and Space Administration (NASA) and carried out at Construction Technology Laboratories show that (1) cements can be made from lunar anorthite and basalt, (2) concrete made with lunar soils as aggregate has strength exceeding 10,000 psi, and (3) a dry mixture of of cement and aggregate wetted by injected steam will simplify concreting procedures and minimize needs for water and heavy equipment. In addition, a preliminary analysis of a prestressed precast concrete structure measuring 120 ft. in diameter and 72 ft. high, shows that a properly designed concrete structure can confine a one atmospheric internal pressure. This project further investigates the effect of lunar temperature extremes on the behavior of precast concrete panels during the construction period. The major work involves calculations of heat flow in concrete panels exposed to the sun on the lunar surface, thermal stresses in the panels caused by the transient heat flow. computer programs were written for the computations, and results are presented in figures 2 to 5. © 1991 American Concrete Institute. All rights reserved.

关键词： computer PROGRAMS CONCRETE PANELS HEAT TRANSFER LUNAR BASES PRECAST CONCRETE PRESTRESSED CONCRETE SUN THERMAL STRESSES

来源：评论

学校读者我要写书评

暂无评论

A Preliminary Implementation for Vehicle Platoon Control System

A Preliminary Implementation for Vehicle Platoon Control Sys...

引用

American Control Conference (ACC)

作者： K S. Chang W. Li A. Shaikhbahai F. Assaderaghi P. Varaiya University of California Berkeley CA USA Graduate Student: Department of Electrical Engineering & Computer Science University of California Berkeley CA 94720 Professor: Department of Electrical Engineering & Computer Science University of California Berkeley CA 94720

This paper presents an implementation of automatic longitudinal control system for a platoon of vehicles. The goal of the control is to maintain vehicle spacings to within several feet, resulting in a substantial increase in a highway capacity. The objective of the paper is to demonstrate the feasibility of this idea by field tests with two vehicles. The authors have integrated all elements of the control system using readily available equipment. The importance of the platoon communication scheme is explained, and experimental results are used to illustrate how the system works.

关键词： Control systems Automatic control Communication system control Acceleration Pressure control Temperature control Velocity measurement Vehicle driving Fluid flow measurement Pressure measurement

来源：评论

学校读者我要写书评

暂无评论

Parallel computers Take Lead in Complex Problem SolvingDespite programming difficulties, parallel computers have already become an essential scientific resource

引用

computer in Physics 1991年第6期5卷 582-584页

作者： Michael R. Leuze Robert C. Ward 1a Staff Scientist in the Mathematical Sciences Section Oak Ridge National Laboratory and Associate Professor of Computer Science at the University of Tennessee 2is currently the Director of the Engineering Physics and Mathematics Division of the Oak Ridge National Laboratory having previously served the Laboratory in many research and managerial capacities

Michael R. Leuze, Robert C. Ward; Parallel computers Take Lead in Complex Problem Solving: Despite programming difficulties, parallel computers have already bec

关键词：

来源：评论

学校读者我要写书评

暂无评论

FIELD SAMPLING OF RESIDUAL AVIATION GASOLINE IN SANDY SOIL

引用

GROUND WATER MONITORING AND REMEDIATION 1991年第2期11卷 107-120页

作者： OSTENDORF, DW LEACH, LE HINLEIN, ES XIE, YF 1 David W. Ostendorf is an associate professor in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department University of Massachusetts Amherst MA 01003). His research interests include unconfined aquifer contamination hazardous waste site remediation and analytical modeling of problems in environmental fluid mechanics. Dr. Ostendorf is a registered professional engineer in Massachusetts and a member of the American Geophysical Union American Society of Civil Engineers Soil Science Society of America Water Pollution Control Federation and Association of Environmental Engineering Professors as well as the National Water Well Association.2 Lowell E. Leach is an environmental engineer with the Robert S. Kerr Environmental Research Laboratory of the U.S. Environmental Protection Agency (RS Kerr Environmental Research Laboratory U.S. EPA P.O. Box 1198 Ada OK74820). Leach received his B.S. ingeological engineering at the University of Oklahoma in 1959 and has been a registered professional engineer in Oklahoma since 1966. With 29 years of experience in field applications of geological engineering he is responsible for developing methodology for sampling ground water and subsurface materials for the Robert S. Kerr Environmental Research Laboratory.3 Erich S. Hinlein is a research assistant in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department University of Massachusetts Amherst MA 01003). His research interests include ground water pollution hazardous waste site investigation and transport processes in unconfined aquifers. Hinlein graduated with a B.S. in electrical and computer engineering from the University of Massachusetts at Amherst in May 1985 and entered the Environmental Engineering Master's Degree Program in January 1989.4 Yuefeng Xie is a postdoctoral research associate in the Environmental Engineering Program of the Civil E

Two complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured field extrusion of core barrels into pint-size Mason jars, while the second consisted of laboratory partitioning of intact stainless steel core sleeves. The barrel extrusion procedure involved jar headspace sampling in a nitrogen-filled glove box, which delineated the 0.7m thick residually contaminated interval for subsequent core sleeve withdrawal from adjacent boreholes. Soil samples removed from the Mason jars (in the field) and sleeve segments (in the laboratory) were subjected to methylene chloride extraction and gas chromatographic analysis to compare their aviation gasoline content. The barrel extrusion sampling method yielded a vertical profile with 0.10m resolution over an essentially continuous 5.0m interval from the ground surface to the water table. The sleeve segment alternative yielded a more resolved 0.03m vertical profile over a shorter 0.8m interval through the capillary fringe. The two methods delivered precise estimates of the vertically integrated mass of aviation gasoline at a given horizontal location, and a consistent view of the vertical profile as well. In the latter regard, a 0.2m thick lens of maximum contamination was found in the center of the capillary fringe, where moisture filled all voids smaller than the mean pore size. The maximum peak was resolved by the core sleeve data, but was partially obscured by the barrel extrusion observations, so that replicate barrels or a half-pint Mason jar size should be considered for data supporting vertical transport analyses in the absence of sleeve partitions.

关键词：

来源：评论

学校读者我要写书评

暂无评论

FULL-WAVE SOLUTION OF DIELECTRIC LOADED WAVE-GUIDES AND SHIELDED MICROSTRIPS UTILIZING FINITE-DIFFERENCE AND THE CONJUGATE-GRADIENT METHOD

引用

INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE computer-AIDED engineering 1991年第4期1卷 346-357页

作者： NARAYANAN, V MANELA, M LADE, RK SARKAR, TK Department of Electrical and Computer Engineering Syracuse University Syracuse New York 13244-1240 Viswanathan Narayanan was born in Bangalore India on December 14 1965. He received the BE degree in Electronics and Communications from B.M.S. College of Engineering Bangalore in 1988. He joined the Department of Electrical Engineering at Syracuse University for his graduate studies in 1989 where he is currently a research assistant. His research interests are in microwave measurements numerical electromagnetics and signal processing. Biographies and photos are not available for M. Manela and R. K. Lade. Tapan K. Sarkar (Sf69-M'76-SM'X1) was born in Calcutta. India on August 2 1948. He received the BTech degree from the Indian Institute of Technology Kharagpur India in 1969 the MScE degree from the University of New Brunswick Fredericton Canada in 1971. and the MS and PhD degrees from Syracuse University. Syracuse NY in 1975. From 1975-1976 he was with the TACO Division of the General Instruments Corporation. He was with the Rochester Institute of Technology (Rochester NY) from 1976-1985. He was a Research Fellow at the Gordon Mckay Laboratory Harvard University Cambridge MA from 1977 to 1978. He is now a Professor in the Department of Electrical and Computer Engineering Syracuse University. His current research interests deal with numerical solutions of operator equations arising in electromagnetics and signal processing with application to system design. He obtained one of the “ best solution” awards in May 1977 at the Rome Air Development Center (RADC) Spectral Estimation Workshop. He has authored or coauthored more than 154 journal articles and conference papers and has written chapters in eight books. Dr. Sarkar is a registered professional engineer in the state of New York. He received the Best Paper Award of the IEEE Transactions on Electromagnetic Compatibility in 1979. He was an Associate Editor for feature articles of the lEEE Antennas arid Propagation Sociefy Newsletter and was

Dynamic analysis of waveguide structures containing dielectric and metal strips is presented. The analysis utilizes a finite difference frequency domain procedure to reduce the problem to a symmetric matrix eigenvalue problem. Since the matrix is also sparse, the eigenvalue problem can be solved quickly and efficiently using the conjugate gradient method resulting in considerable savings in computer storage and time. Comparison is made with the analytical solution for the loaded dielectric waveguide case. For the microstrip case, we get both waveguide modes and quasi-TEM modes. The quasi-TEM modes in the limit of zero frequency are checked with the static analysis which also uses finite difference. Some of the quasi-TEM modes are spurious. This article describes their origin and discusses how to eliminate them. Numerical results are presented to illustrate the principles.

关键词： Waveguides

来源：评论

学校读者我要写书评

暂无评论

ADAPTING AVAILABLE FINITE-ELEMENT STRUCTURAL PROGRAMS TO SOLVE 3-DIMENSIONAL HIGH-FREQUENCY ELECTROMAGNETIC PROBLEMS

引用

INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE computer-AIDED engineering 1991年第4期1卷 386-394页

作者： NAVARRO, EA FEMENIA, JM SUCH, V Departamento de Fisica Aplicada Universitat de València C Doctor Moliner 50.46100 Burjassot (València) Spain Enrique A. Navarro was born in Sueca (Valéncia) Spain on January 18 1965. He received the Licenciado degree in Physics from the Universitat de Valéncia Spain in 1988. After working on Systems Simulation at GMV S.A. Madrid. Spain. he returned to the Universitat de Valéncia in 1980 where he began to study for the PhD degree in the Department de Fésica Aplicada. Universitat de Valéncia Spain. He is currently Assistant Professor in the Department of Applied Physics. His rescarch interests are in the area of microwave engineering and numerical method for solving electromagnetic wave propagation problems. Jose M. Femenia was born in Segorbe (Castellón) Spain in 1962. He obtained in Physics from the the Licenciado degree in Physics from the Universitat de Valéncia Spain in 1987 Universitat. After working in Laser and Optical Technology in the Department d'Optica di la Universitat de Valéncia he received a grant to work in numerical techniques for electromagnetics in the Departnment de Fisica Aplicada. He currently works in Computer Science and Communications in the Servei d'lnformàtica de la Universitat de Valéncia. Vicente Such was born in Valéncia Spain on August 10 1943. He received the Licenciado degree in Physics in 1967 and the PhD degree in 1971 both from the Universitat de Valéncia Spain. From 1967 to 1974 he was Assistant Professor with the Department of Electricity and Magnetism Universitat de Valéncia and with the Universitat Politécnica de Valkncia. From1974 to 1981 he was Professor of Electricity and Magnetism at the Universitat de Extremadura Universitat de Valéncia and Universidad de Palma de Mallorca Spain. He is now a Professor in the Department of Applied Physics at Universitat de Valéncia. His current research interests deal with microstrip antennas arrays Microwave passsive circuits and computer methods in electromagnetics.

The adaptation of available structural mechanics software to solve microwave problems is possible by the analogy between the differential equations. A brief review of the analogy between transverse or shear waves in elasticity and electromagnetic waves is presented, followed by a more detailed discussion of the adaptation of a program to obtain the resonant frequencies of a rectangular resonant cavity, doing a three-dimensional analysis. The geometry of the electric field is also obtained for the resonant modes.

关键词： Microwaves

来源：评论

学校读者我要写书评

暂无评论

Additional core losses in induction machines with pwm inverter

引用

European Transactions on Electrical Power 1991年第4期1卷 189-193页

作者： Wahsh, S. El‐Bakry, M. Dr.-Ing. Mahmoud El-Bakry (1942) received his B. Sc. and M. Sc. dcgrees in Electrical Engineering (Comrnunications & Electronics) from Cairo UniversityEgypt in 1963 and 1974 respectively. and the Dr.-Ing. degree from University of BremedGermany in 1979. He is now Associate Professor at Power Electronics and Energy Conversion Department of the Electronics Research Institute Dokki Cairo. His research activities include Power Electronics Operation Research and Computer Hardware. He is working on research projects with the Egyptian industry to introduce modem computer technology in management and production. (Electronics Research Institute Power Electronics Lab.Sh. El-Tahrir Dokki Cairo Egypt T +202/71 1631) Prof. Said Wahsh (1945) received the B. Sc. degree in Electrical Engineering from Ain Shams University Cairo/Egypt in 1967. In 1973 he joined National Research Center (NRC) as a researcher in the Electrical and Electronic Laboratory. He received his Ph. D. degree in Electrical Drives from the Budapest Technical University/Hungary in 1980. Since 1980 he is working as Assistant Professor at Electronics Research Institute (ERI) NRC and since 1984 he is head of the Power Electronics Laboratory. In 1990 he became Professor of Electrical Engineering in ERI. His major field of interest includes Power Electronics and Electrical Drives.(Electronics Research Institute Power Electronics Lab. Sh. El-Tahrir Dokki Cairo Egypt.T +202/71 1631)

Induction machine drives with squirrel‐cage rotor will more and more replace the DC motor for its various advantages. The additional motor losses are essentially copper and iron losses in stator and rotor. Iron losses are significantly influenced by machine construction, magnetic materials used and supply type. Different formulae and estimations are given in the literature for these losses. In this contribution a method is presented for the calculation of additional iron losses in induction machines with PWM inverter. Two limits are deduced for the calculation of eddy‐current losses, within which the losses lie, and which agree with the theoretical basis and most empirical formulae given in the previous works. Similarly a new method is proposed for the additional hysteresis losses. The proposed methods give good results compared with the other known methods. Copyright © 1991 John Wiley & Sons, Ltd.

关键词：

来源：评论

学校读者我要写书评

暂无评论

LABORATORY PROCEDURES FOR DETERMINING 30 TIME-TEMPERATURE PARAMETERS FOR CONVECTIVE HEAT PROCESSING: A RESEARCH TOOL FOR NUTRIENT ANALYSIS

引用

Journal of Foodservice 1991年第1期6卷

作者： N. IBRAHIM Ph.D. N. UNKLESBAY Ph.D K. UNKLESBAY Ph.D. K. BIEDRZYCKI Ph.D. Professor College of Agriculture Food Science and Nutrition Department Room 122 Eckles Hall University of Missouri-Columbia Columbia MO 65211 Professor College of Engineering Electrical and Computer Engineering Department University of Missouri-Columbia Columbia MO 65211 Assistant Professor Human Nutrition Institute Warsaw Agricultural University Nowoursynowska 166 02–765 Warsaw POLAND

A laboratory procedure was developed to study a wide range of time and temperatures during convective heat processing of a pork/soy hull product. The procedure reduces labor costs associated with extensive nutrient analyses studies. As experimental examples, these heat processing parameters were used to examine the yield and fat and cholesterol content of the product. The curve fits for time-temperature profiles were identified as quadratic equations. To further quantify these profiles, two expressions were calculated: (1) the integral (°C min), or area under the curve, and (2) the second derivative (°/min 2 ), or acceleration of the heat penetration curve. The integral of the quadratic curve fit of time-temperature profiles ranged from 156 to 6318°C/min. Positive correlations were found between moisture content and product yield and the fat content and cholesterol. Negative relationships were found between the integral and product yield, and the integral and moisture content. Recommendations were made for applying this procedure for nutrient analyses studies.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A METHOD FOR ASSESSING RESIDUAL NAPL BASED ON ORGANIC-CHEMICAL CONCENTRATIONS IN SOIL SAMPLES

引用

GROUND WATER MONITORING AND REMEDIATION 1991年第2期11卷 128-136页

作者： FEENSTRA, S MACKAY, DM CHERRY, JA Stan Feenstra is a hydrogeochemist and president of Applied Groundwater Research Ltd. in Mississauga Ontario He received a B.Sc. in earth sciences and an M.Sc. in hydrogeology from the University of Waterloo in 1978 and 1980 respectively and was designated a Certified Ground Water Professional by AGWSE in 1989. Since 1980 he has been a ground water consultant with Golder Associates in Mississauga Ontario and Zenon Environmental in Burlington Ontario and founded Applied Groundwater Research Ltd. in 1987. Feenstra specializes in the hydrogeochemical evaluation of ground water contamination at waste disposal facilities and chemical spill sites. He is currently a Ph.D. candidate in hydrogeology and research associate in the Waterloo Centre for Ground Water Research at the University of Waterloo (Waterloo Ontario N2L 3G1) and is involved in research related to the behavior of dense organic solvents in ground water. Douglas M. Mackay is an adjunct professor at the Waterloo Centre for Groundwater Research at the University of Waterloo Waterloo Ontario (N2L3G1). Dr. Mackay received a B.S. in engineering and M.S. and Ph.D. in civil engineering from Stanford University in 1970 1973 and 1981 respectively. From 1986 to 1990 he was a faculty member of the Environmental Science and Engineering Program of the UCLA School of Public Health. His research focuses on field studies of transport and fate of organic chemicals in ground water various scale studies of decontamination of soil and ground water and ground water monitoring technologies. John A. Cherry is a professor at the Waterloo Centre for Groundwater Research at the University of Waterloo Waterloo Ontario (N2L 3G1). He received his B.S. in geological engineering from the University of Saskatchewan in 1962. He received his M.S. from the University of California at Berkeley in 1964 and his Ph.D. from the Department of Geology at the University of Illinois in 1966. His research interests include the field study and modeling of contaminants in ground wat

Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost-effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non-aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. The presence of NAPL pools may be evident as a floating or sinking phase in monitoring wells. The residual NAPL contamination may be identified in soil samples if residual contents are high and contaminated zones in the soil cores are thick. However, visual identification may not be effective if residual contents ar elow or if the NAPL residual is distributed heterogeneously in the samples. The chemical analysis of soil samples provides a measure of the total chemical concentration in the soil but cannot determine directly whether NAPL is present in the samples. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or > 10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil

关键词：

来源：评论

学校读者我要写书评

暂无评论

A STUDY OF THE EFFECT OF THE TANK DIAMETER ON THE THERMAL STRATIFICATION IN LPG TANKS SUBJECTED TO FIRE ENGULFMENT

引用

JOURNAL OF HAZARDOUS MATERIALS 1990年第1-2期25卷 19-31页

作者： HADJISOPHOCLEOUS, GV SOUSA, ACM VENART, JES Research Associate at the National Fire Laboratory Institute for Research in Construction National Research Council of Canada Canada Professor at the Department of Mechanical Engineering University of New Brunswick Fredericton New Brunswick.U.S.A. Director of the Fire Science Centre and Professor at the Department of Mechanical Engineering University of New Brunswick Fredericton New Brunswick.U.S.A.

This paper describes a mathematical model developed to study the behaviour of LPG tanks when subjected to fire conditions. The model consists of a number of field and zone sub-models which are used to simulate the various physical phenomena taking place during the tank engulfment period. To verify the model, prediced results are compared with full scale experimental data obtained by the Health and Safety Executive, U.K. (ref.1). The comparisons indicate that the model can accurately predict the tank pressure and time to first valve opening. The model is used to investigate the effect of the tank diameter on the thermal stratification in the liquid region.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：