TY - JOUR TI - Group-specific small-subunit rRNA hybridization probes to characterize filamentous foaming in activated sludge systems T2 - Applied and Environmental Microbiology AB - Foaming in activated sludge systems is characterized by the formation of a thick, chocolate brown-colored scum that floats on the surface of aeration basins and secondary clarifiers. These viscous foams have been associated with the presence of filamentous mycolic acid-containing actinomycetes. To aid in evaluating the microbial representation in foam, we developed and characterized group-, genus-, and species-specific oligonucleotide probes targeting the small subunit rRNA of the Mycobacterium complex, Gordona spp., and Gordona (Nocardia) amarae, respectively. The use of a universal base analog, 5-nitroindole, in oligonucleotide probe design was evaluated by comparing the characteristics of two different versions of the Mycobacterium complex probe. The temperature of dissociation of each probe was determined. Probe specificity studies with a diverse collection of 67 target and nontarget rRNAs demonstrated the specificity of the probes to the target groups. Whole-cell hybridizations with fluorescein- and rhodamine-labeled probes were performed with pure cultures of various members of the Mycobacterium complex as well as with environmental samples from a full-scale activated sludge plant which experienced foaming. Quantitative membrane hybridizations with activated sludge and anaerobic digester foam showed that 15.0 to 18.3% of the total small-subunit rRNAs could be attributed to members of the Mycobacterium complex, of which a vast majority consisted of Gordona rRNA. Several G. amarae strains made up only a very small percentage of the Gordona strains present. We demonstrated that group-specific rRNA probes are useful tools for the in situ monitoring and identification of filamentous bacteria in activated sludge systems. DA - 1997/// PY - 1997/// DO - 10.1128/AEM.63.3.1107-1117.1997 UR - https://publons.com/wos-op/publon/7119262/ ER - TY - CONF TI - The Use of Computational Fluid Dynamics for Improving Clearwell Design for CT Compliance AU - Hagstrom, J.P. AU - Crozes, G. AU - Reddy, S. AU - Verghes, V. AU - Clark, M.M. AU - Ducoste, J.J. AU - Burns, C. T2 - American Water Works Association Computer Conference C2 - 1997/// C3 - Proceedings of the American Water Works Association Computer Conference CY - Austin, Texas DA - 1997/// PY - 1997/// ER - TY - CONF TI - The Influence of Tank Size and Impeller Type on Floc Size Distribution AU - Ducoste, J.J. AU - Clark, M.M. T2 - American Water Works Association National Conference C2 - 1997/// C3 - Proceedings of the American Water Works Association National Conference CY - Atlanta, Georgia DA - 1997/// PY - 1997/// ER - TY - RPRT TI - Biodegradative Analysis of Municipal Solid Waste in Laboratory-Scale Landfills AU - Barlaz, M.A. AU - Eleazer, W.E. AU - Odle, W.S. AU - Qian, X. AU - Wang, Y.-S. A3 - National Risk Management Research Laboratory DA - 1997/9// PY - 1997/9// M1 - 600/R-97-071 M3 - US Environmental Protection Agency Report PB - National Risk Management Research Laboratory SN - 600/R-97-071 ER - TY - CONF TI - Life-Cycle Inventory of a Modern Municipal Solid Waste Landfill AU - Camobreco, V. AU - Ham, R.K. AU - Barlaz, M.A. AU - Repa, E. AU - Felker, M. AU - Rousseau, C. AU - Rathle, J. T2 - Sixth International Waste Management and Landfill Symposium C2 - 1997/// CY - Cagliari, Italy DA - 1997/// PY - 1997/10/2/ ER - TY - CONF TI - Benzaldehyde Degradation Under Mixed Iron Reducing/Fermentative Conditions AU - Kota, S. AU - Barlaz, M.A. AU - Borden, R.C. T2 - Spring Meeting of the American Geophysical Union C2 - 1997/// CY - Baltimore, MD DA - 1997/// PY - 1997/5/26/ ER - TY - CONF TI - Microbial and Geochemical Heterogeneity in Gasoline Contaminated Aquifers Undergoing Intrinsic Bioremediation AU - Ress, B.B. AU - Kota, S. AU - Kao, J. AU - Barlaz, M.A. AU - Borden, R.C. T2 - Spring Meeting of the American Geophysical Union C2 - 1997/// CY - Baltimore, MD DA - 1997/// PY - 1997/5/26/ ER - TY - CONF TI - Biodegradation Potential of Alkylbenzenes and Phenols in Landfills AU - Wang, Y.S. AU - Barlaz, M.A. T2 - 52nd Purdue Industrial Waste Conference C2 - 1997/// CY - Purdue University, West Lafayette, IN DA - 1997/// PY - 1997/5/5/ ER - TY - CONF TI - Estimating Municipal Waste Combustor Emissions as a Function of Waste Composition AU - Nishtala, S.R. AU - Harrison, K.W. AU - Barlaz, M.A. T2 - Fifth Annual North American Waste-to-Energy Conference, Air & Waste Management Association C2 - 1997/// CY - Research Triangle Park, NC DA - 1997/// PY - 1997/4/22/ ER - TY - JOUR TI - Behavior of CFRP for Prestressing and Shear Reinforcements of Concrete Highway Bridges AU - Fam, A. AU - Rizkalla, S. AU - Tadros, G. T2 - ACI Structural Journal DA - 1997/// PY - 1997/// VL - 94 IS - 1 SP - 77–86 ER - TY - JOUR TI - Serviceability of Concrete Beams Prestressed by Carbon Fiber Reinforced Plastic Bars AU - Abdelrahman, A. AU - Rizkalla, S. T2 - ACI Structural Journal DA - 1997/7// PY - 1997/7// VL - 94 IS - 4 SP - 447–457 ER - TY - CHAP TI - Microbial Studies of Landfills and Anaerobic Refuse Decomposition AU - Barlaz, M.A. T2 - Manual for Environmental Microbiology A2 - Hurst, Christon A2 - Knudsen, Guy PY - 1997/// PB - American Society of Microbiology ER - TY - JOUR TI - Fiber-optic Bragg grating sensors for bridge monitoring AU - Maaskant, R. AU - Alavie, T. AU - Measures, R.M. AU - Tadros, G. AU - Rizkalla, S.H. AU - Guha-Thakurta, A. T2 - Cement and Concrete Composites AB - Fiber-optic Bragg grating strain sensors hold a great deal of potential for structural monitoring because of their exceptional stability and demonstrated potential for long-term monitoring. This sensing technology takes advantage of a spectrally encoded signal which provides inherent immunity from signal intensity fluctuations which plague many other fiber-optic and electronic sensing techniques. This results in measurement stability and lead/interconnect insensitivity which permit longterm and intermittent monitoring with high resolution and accuracy. Fiber-optic grating sensors are intrinsic to the optical fiber, thus capitalizing on its extremely small size and inherent strength and durability. Recent results are provided from a sensor array installed in a road bridge. The strain sensors are attached to both steel and carbon-fiber-reinforced plastic prestressing tendons, which are embedded in the precast girders of the bridge. Measurements of traffic loads and the relaxation behaviour of the tendons are presented. The potential of fiber grating technology is briefly discussed including its application in long-gage strain-sensing and strain-distribution measurements. DA - 1997/1// PY - 1997/1// DO - 10.1016/s0958-9465(96)00040-6 VL - 19 IS - 1 SP - 21-33 J2 - Cement and Concrete Composites LA - en OP - SN - 0958-9465 UR - http://dx.doi.org/10.1016/s0958-9465(96)00040-6 DB - Crossref KW - fiber optic grating KW - Bragg grating KW - strain sensor KW - bridge KW - concrete KW - pre-stress KW - CFRP (carbon fiber reinforced plastic) KW - strain relaxation KW - structural monitoring KW - field measurements ER - TY - JOUR TI - Multibolted Joints for GFRP Structural Members AU - Hassan, Nahla K. AU - Mohamedien, Mohamed A. AU - Rizkalla, Sami H. T2 - Journal of Composites for Construction AB - For the past few decades, aerospace industry was the major user of advanced composite materials. Recently, civil engineers and the construction industry began to realize the potential of these materials in providing remedies for many problems associated with deterioration and corrosion of infrastructures. In light of this, a comprehensive experimental investigation was conducted at the University of Manitoba to study the behavior of multibolted connections using glass fiber-reinforced plastic members. A total of 105 multibolted double shear lap connections were tested. The effect of various parameters including the width of the structural member, edge distance, number of bolts, bolt pattern, pitch, thickness of the members, and direction of fibers with respect to the applied load were examined. This paper analyzes the experimental program, test results, and the various modes of failure as affected by the previously noted parameters. DA - 1997/2// PY - 1997/2// DO - 10.1061/(asce)1090-0268(1997)1:1(3) VL - 1 IS - 1 SP - 3-9 J2 - Journal of Composites for Construction LA - en OP - SN - 1090-0268 1943-5614 UR - http://dx.doi.org/10.1061/(asce)1090-0268(1997)1:1(3) DB - Crossref ER - TY - JOUR TI - Rational Model for Multibolted Connections for GFRP Members AU - Hassan, Nahla K. AU - Mohamedien, Mohamed A. AU - Rizkalla, Sami H. T2 - Journal of Composites for Construction AB - Bolted connections are most suitable for civil engineering applications since they are easy to inspect, have low construction costs, are easy to manufacture, and offer reliability compared with bonded joints. However, using advanced composite material members with unidirectional fibers could create a state of high stress concentration around the bolt holes due to their inherent geometric discontinuities. Due to a lack of information and the need for understanding the mechanism of these connections, a comprehensive experimental and analytical investigation was conducted at the University of Manitoba to study and to determine the behavior of bolted connections using glass fiber-reinforced plastic (GFRP) structural members. Based on the test results and observed behavior, a design procedure is introduced that accounts for the material orthotropy, pseudoyielding capability, and other factors that influence the connection behavior. The proposed rational model is capable of predicting the ultimate capacity of the multibolted connection and the failure mode. The generic nature of the proposed design guidelines can be applied to a multitude of composite material systems. DA - 1997/5// PY - 1997/5// DO - 10.1061/(asce)1090-0268(1997)1:2(71) VL - 1 IS - 2 SP - 71-78 J2 - Journal of Composites for Construction LA - en OP - SN - 1090-0268 1943-5614 UR - http://dx.doi.org/10.1061/(asce)1090-0268(1997)1:2(71) DB - Crossref ER - TY - JOUR TI - Turbulence in flocculators: Effects of tank size and impeller type AU - Ducoste, Joel J. AU - Clark, Mark M. AU - Weetman, Ronald J. T2 - AIChE Journal AB - Past research shows that for the same power per unit volume, flocculation performance varies with tank size and impeller type. This study was performed to characterize effects of scale and impeller design on turbulence produced in the flocculation process. The study was performed with a Rushton turbine and an A310 foil impeller in three square tanks of 5-, 28- and 560-L volume. Fluid velocities were measured using a dual-channel laser Doppler velocimeter with an enhanced burst spectrum analyzer. Flocculation tanks were operated at a constant average unit-mass energy-dissipation rate of 0.0016 m2/s3. The results show that the turbulence intensity and local turbulent energy-dissipation rate were higher for the Rushton turbine than for the A310 impeller. The turbulence intensity was found to increase with increasing tank size regardless of impeller type. The local turbulent energy dissipation rate decreased for the Rushton turbine and remained constant for the A310 impeller with increasing tank size. DA - 1997/2// PY - 1997/2// DO - 10.1002/aic.690430206 VL - 43 IS - 2 SP - 328-338 J2 - AIChE J. LA - en OP - SN - 0001-1541 1547-5905 UR - http://dx.doi.org/10.1002/aic.690430206 DB - Crossref ER - TY - CONF TI - Quantification of uncertainty in remotesensing-based school bus CO and hydrocarbon emission factors AU - Frey, H.Christopher C2 - 1997/// C3 - Proceedings of the Air & Waste Management Association's Annual Meeting & Exhibition DA - 1997/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031354445&partnerID=MN8TOARS ER - TY - JOUR TI - Optimal design of advanced power systems under uncertainty AU - Diwekar, U.M. AU - Rubin, E.S. AU - Frey, H.C. T2 - Energy Conversion and Management DA - 1997/// PY - 1997/// VL - 38 IS - 15-17 SP - 1725-1735 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031259174&partnerID=MN8TOARS ER - TY - JOUR TI - Modeling and evaluation of externally fired combined cycle using ASPEN AU - Agrawal, P. AU - Frey, H.C. T2 - Journal of Energy Engineering DA - 1997/// PY - 1997/// VL - 123 IS - 3 SP - 69-86 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-6144248166&partnerID=MN8TOARS ER - TY - CONF TI - Bootstrap methods for quantitative analysis of variability and uncertainty in exposure and risk assessment AU - Frey, H.Christopher C2 - 1997/// C3 - Proceedings of the Air & Waste Management Association's Annual Meeting & Exhibition DA - 1997/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031344095&partnerID=MN8TOARS ER - TY - JOUR TI - Group-specific small-subunit rRNA hybridization probes to characterize filamentous foaming in activated sludge systems. AU - Reyes, F. L. AU - Ritter, W. AU - Raskin, L. T2 - Appl Environ Microbiol DA - 1997/// PY - 1997/// VL - 63 IS - 3 SP - 1107-17 ER - TY - JOUR TI - Group-specific small-subunit rRNA hybridization probes to characterize filamentous foaming in activated sludge systems AU - DelosReyes, FL AU - Ritter, W AU - Raskin, L T2 - Applied and Environmental Microbiology DA - 1997/// PY - 1997/// VL - 63 IS - 3 SP - 1107-1117 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:A1997WL14400047&KeyUID=WOS:A1997WL14400047 ER - TY - JOUR TI - Modeling and verifying active structural control systems T2 - Science of Computer Programming DA - 1997/// PY - 1997/// VL - 29 IS - 1-2 SP - 99-122 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031185496&partnerID=MN8TOARS ER - TY - JOUR TI - A mathematical programming approach for generating alternatives in discrete structural optimization T2 - Engineering Optimization DA - 1997/// PY - 1997/// VL - 28 IS - 1-2 SP - 1-31 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0030703305&partnerID=MN8TOARS ER - TY - CONF TI - Pile buckling capacity and corresponding first modes AU - Gabr, M. A. AU - Wang, J. AU - Kiger, S. A. A2 - L.A. Godoy, M. Rysz A2 - Suarez, L.E. C2 - 1997/// C3 - Mechanics Pan-America 1997 :selected and extended papers from the 5th Pan-American Congress of Applied Mechanics, January 1997, San Juan, Puerto Rico DA - 1997/// PB - New York: American Society of Mechanical Engineers ER - TY - CONF TI - Physical observations from shallow-buried explosive experiments in geogrid-reinforced earth AU - Ohrt, A. P. AU - Gabr, M. A. C2 - 1997/// C3 - Geosynthetics '97 Conference proceedings DA - 1997/// PB - St. Paul: Industrial Fabrics Association International SN - 9780935803068 ER - TY - JOUR TI - First exposure performance of the bentonite component of a GCL in a low pH, calcium enriched environment, testing and acceptance criteria for geosynthetic clay liners AU - Quaranta, J. D AU - Gabr, M. A. AU - Bowders, J. J. T2 - ASTM Special Technical Publications DA - 1997/// PY - 1997/// VL - 1308 IS - 1 SP - 162-167 ER - TY - CONF TI - Subsurface flushing of BTEX using prefabricated vertical drains (PVDs) in clay AU - Gabr, M. A AU - Szabo, D. AU - Williamson, A. AU - Sabodish, M. C2 - 1997/// C3 - Environment `97, International Conference on Environmental Management and Technologies DA - 1997/// VL - 2 M1 - 6 ER - TY - RPRT TI - Journal of Computing in Civil Engineering: Editorials AU - Rasdorf, W. A3 - Raleigh, N.C.: Department of Civil Engineering, North Carolina State University DA - 1997/// PY - 1997/// PB - Raleigh, N.C.: Department of Civil Engineering, North Carolina State University ER - TY - JOUR TI - Importance of mentoring in civil engineering education AU - Rasdorf, W. J. T2 - Journal of Professional Issues in Engineering Education and Practice DA - 1997/// PY - 1997/// VL - 123 IS - 1 SP - 5 ER - TY - JOUR TI - Water retention functions of four nonwoven polypropylene geotextiles AU - Stormont, JC AU - Henry, KS AU - Evans, TM T2 - GEOSYNTHETICS INTERNATIONAL AB - The water retention functions of four nonwoven polypropylene geotextiles were measured. Each of the four geotextile types were tested in two conditions: new and cleaned. The water retention functions of each geotextile specimen were found to be hysteretic. The new geotextile specimens always contained more water at comparable suction heads than the cleaned geotextile specimens. At zero suction head, the new specimens approached saturation, whereas the cleaned specimens were less than 20% saturated. DA - 1997/// PY - 1997/// DO - 10.1680/gein.4.0110 VL - 4 IS - 6 SP - 661-672 SN - 1751-7613 KW - geotextile KW - water entry suction KW - water retention function KW - capillary rise KW - capillary barrier ER - TY - JOUR TI - Biodegradability of municipal solid waste components in laboratory-scale landfills AU - Eleazer, WE AU - Odle, WS AU - Wang, YS AU - Barlaz, MA T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - The objective of this research was to characterize the anaerobic biodegradability of municipal refuse components by measuring methane yields, the extent of cellulose and hemicellulose decomposition, and leachate toxicity. Tests were conducted in quadruplicate in 2-L reactors operated to obtain maximum yields. Measured methane yields for grass, leaves, branches, food waste, coated paper, old newsprint, old corrugated containers, and office paper were 144.4, 30.6, 62.6, 300.7, 84.4, 74.3, 152.3, and 217.3 mL of CH4/dry g, respectively. Although, as a general trend, the methane yield increased as the cellulose plus hemicellulose content increased, confounding factors precluded establishing a quantitative relationship. Similarly, the degree of lignification of a particular component was not a good predictor of the extent of biodegradation. With the exception of food waste, leachate from the decomposition of refuse components was not toxic as measured by using an anaerobic toxicity assay. DA - 1997/3// PY - 1997/3// DO - 10.1021/es9606788 VL - 31 IS - 3 SP - 911-917 SN - 0013-936X ER - TY - CONF TI - The effect of GAC service time on the adsorption of periodic episodes of atrazine AU - Knappe, D. R. U. AU - Snoeyink, V. L. AU - Roche, P. AU - Prados, M. J. AU - Bourbigot, M. M. C2 - 1997/// C3 - Proceedings of the American Water Works Association Annual Conference, Atlanta, GA, June 15-19, 1997 DA - 1997/// VL - 89 M1 - 1997 June ER - TY - CONF TI - Nitrogen removal in constructed wetlands treating high nitrogen landfill leachate AU - Liehr, S. K. AU - Kozub, D. D. AU - Rash, J. K. C2 - 1997/// C3 - Proceedings WEFTEC '97: Water Environment Federation 70th Annual Conference & Exposition, Chicago, Illinois, October 18-22, 1997 DA - 1997/// M1 - 1997 Oct. ER - TY - JOUR TI - Microbial and geochemical heterogeneity in gasoline contaminated aquifers undergoing intrinsic bioremediation AU - Ress, B. B. AU - Kota, S. AU - Kao, J. AU - Barlaz, M. A. AU - Borden, R. C. T2 - Eos (Richmond, Va.) DA - 1997/// PY - 1997/// VL - 78 IS - 17 SP - S159 ER - TY - RPRT TI - Intrinsic bioremediation of gasoline-contaminated aquifers: Biodegradation rate measurement and microbial ecology AU - Kota, S. AU - Hunt, M. J. AU - Barlaz, M. A. AU - Borden, R. C. A3 - Raleigh, NC: University of North Carolina Water Resources Research Institute C6 - 308 CN - MF NC DOCS G67 10:308 [Hill Microform RR] DA - 1997/// PY - 1997/// SP - 63 PB - Raleigh, NC: University of North Carolina Water Resources Research Institute ER - TY - CONF TI - Biodegradative analysis of municipal solid waste in laboratory-scale landfills AU - Barlaz, M. A. C2 - 1997/// C3 - US Environmental Protection Agency Report #EPA 600/R-97-071, Washington, D.C. DA - 1997/// M1 - 1997 ER - TY - JOUR TI - Benzaldehyde degradation under mixed iron reducing / fermentative conditions AU - Kota, S. AU - Barlaz, M. A. AU - Borden, R.C. T2 - Eos (Richmond, Va.) DA - 1997/// PY - 1997/// VL - 78 IS - 17 SP - S121 ER - TY - CHAP TI - Uncertainty evaluation in capital cost projection AU - Frey, H. C. AU - Rubin, E. S. T2 - Encyclopedia of chemical processing and design, Vol. 59 CN - TP9 .E66 PY - 1997/// VL - 59 SP - 480-494 PB - New York: Marcel Dekker ER - TY - CONF TI - Spatial variability in intrinsic bioremediation rates: Effect on contaminant transport AU - Daniel, R. A. AU - Borden, R. C. C2 - 1997/// C3 - In Situ and On Site Bioremediation: Papers from the Fourth International In Situ and On-Site Bioremediation Symposium, New Orleans, April 28-May 1, 1997 CN - TD192.5 .I56 1997 DA - 1997/// VL - 1 SP - 29-34 PB - Columbus: Battelle Press ER - TY - CONF TI - Field studies of BTEX and MTBE intrinsic bioremediation C2 - 1997/// C3 - Field studies of BTEX and MTBE intrinsic bioremediation (API publication; no. 4654) DA - 1997/// VL - 4654 SP - 198 PB - American Petroleum Institute ER - TY - RPRT TI - Factors limiting intrinsic bioremediation of gasoline-contaminated aquifers AU - Kota, S. AU - Hunt, M. J. AU - Barlaz, M. A. AU - Borden, R. C. A3 - Raleigh, NC: University of North Carolina Water Resources Research Institute C6 - 1997 DA - 1997/// PY - 1997/// PB - Raleigh, NC: University of North Carolina Water Resources Research Institute ER - TY - RPRT TI - Evaluation of wet ponds for protection of public water supplies AU - Borden, R. C. AU - Dorn, J. L. AU - Stillman, J. B. AU - Liehr, S. K. A3 - Raleigh, NC: University of North Carolina Water Resources Research Institute C6 - 311 CN - HD1694.N8 N6 no. 311 [Hill] DA - 1997/// PY - 1997/// PB - Raleigh, NC: University of North Carolina Water Resources Research Institute ER - TY - CONF TI - Environmental research brief AU - Borden, R. C. AU - Hunt, M. J. AU - Shafer, M. B. AU - Barlaz, M. A. C2 - 1997/// C3 - Anaerobic biodegradation of BTEX in aquifer material CN - EP 1.96:600/S-97/003 DA - 1997/// SP - 9 PB - Ada, OK: U.S. Environmental Protection Agency, Research and Development, National Risk Management Research Laboratory ER - TY - CONF TI - Discrete meso-element simulation of chemical reactions in shear bands AU - Tamura, S. AU - Horie, Y. A2 - S. C. Schmidt, D. P. Dandekar A2 - Forbes, J. W. C2 - 1997/// C3 - Proceedings of the Conference of the American Physical Society Topical Conference on Shock Compression of Condensed Matter held at Amherst, Massachusetts, July 27-August 1, 1997 CN - QC173.4.C65 A43 1997 DA - 1997/// VL - 429 SP - 377-380 ER - TY - CONF TI - Application of 3-D computer modeling using digital photogrammetry to measure shoreline change AU - Overton, M. F. AU - Fisher, J. S. C2 - 1997/// C3 - Coastal engineering 1996: Proceedings of the twenty-fifth international conference, September 2-6, 1996, The Peabody Hotel, Orlando 1997 CN - TC203.5 .C6184 1997 DA - 1997/// ER - TY - BOOK TI - CAD-integrated real-time control for robotic excavation and pipe-laying: Development and testing AU - Bernold, L. E. AU - Huang, X.-D. CN - TD 2.30:97-044 DA - 1997/// PY - 1997/// PB - McLean, VA: U.S. Dept. of Transportation, Federal Highway Administration, Research and Development, Turner-Fairbank Highway Research Center ER - TY - CHAP TI - Validation of a generalized delay model for vehicle-actuated signals AU - Rouphail, N. M. AU - Anwar, M. AU - Fambro, D. AU - Sloup, P. AU - Perez, C. T2 - Highway capacity issues and analysis CN - TE7 .H5 no. 1572 PY - 1997/// SP - 105-111 PB - Washington, DC: National Academy Press SN - 0309061504 ER - TY - CHAP TI - Validation of a generalized delay model for oversaturated conditions AU - Engelbert, R. AU - Fambro, D. AU - Rouphail, N. T2 - Highway capacity issues and analysis CN - TE7 .H5 no. 1572 PY - 1997/// SP - 122-130 PB - Washington, DC: National Academy Press SN - 0309061504 ER - TY - BOOK TI - Three dimensional slope stability analysis and support strategies for conical excavations: Final report to Carolina Power and Light AU - Borden, R. H. AU - Geng, C. DA - 1997/// PY - 1997/// PB - Carolina Power and Light ER - TY - CHAP TI - Temperature correction of backcalculated moduli and deflections using linear viscoelasticity and time-temperature superposition AU - Park, S. AU - Kim, Y. R. T2 - Pavement research issues AB - New analytical procedures for temperature correction of backcalculated asphalt concrete moduli and surface deflections were developed based on the theory of linear viscoelasticity and the time-temperature superposition principle and verified using falling weight deflectometer data and field temperature measurements. The new correction procedures explicitly utilize the thermorheological properties of the asphalt mixture. The resulting temperature-modulus correction factors depend only on the relaxation modulus and time-temperature shift factor of the mixture. The temperature-deflection correction factor depends on both the material properties and the layer thicknesses of the pavement section. Emphasis has been placed on the analytical description of the mixture’s thermoviscoelasticity responsible for temperature effects on mixture modulus and pavement deflection. A mechanistic framework for dealing with temperature correction problems for asphalt pavement has been introduced. CN - TE7 .H5 no. 1570 PY - 1997/// DO - 10.3141/1570-13 SP - 108-117 PB - Washington, DC: National Academy Press SN - 0309061539 ER - TY - JOUR TI - Semantic validation of product and process models AU - Baugh, J. W. AU - Chadha, H. S. T2 - Journal of Computing in Civil Engineering AB - This paper describes the use of equational specifications and process algebras in developing product and process models. These formal approaches enable an abstract and precise description of products, where both syntactic and semantic checks are used for validation. In addition, refinement methodologies are provided that relate the abstract specifications to implementations in data modeling languages such as EXPRESS. We show how these formal approaches, initially designed for specifying software and hardware modules, relate to current standards and research in product and process modeling. Our approach is illustrated with examples of both product and process modeling. The general architecture engineering and construction reference model (GARM) is modeled in an equational style using the Larch family of specification languages. The partitioned engineering data flow model (PANDA), a graphical approach for describing process models in facility engineering, is modeled as a process algebraic system in calculus of communicating systems (CCS). Both examples are validated by proving that they satisfy certain syntactic and semantic properties. DA - 1997/// PY - 1997/// DO - 10.1061/(ASCE)0887-3801(1997)11:1(26) VL - 11 IS - 1 SP - 26-36 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0343536396&partnerID=MN8TOARS ER - TY - CHAP TI - Propagation and healing of microcracks in asphalt concrete and their contributions to fatigue AU - Little, D. N. AU - Lytton, R. L. AU - Williams, D. AU - Kim, Y. R. T2 - Asphalt science and technology CN - TP692.4.A8 A68 1997 PY - 1997/// SP - 149-195 PB - New York, NY: Marcel Dekker, Inc. ER - TY - CONF TI - Permeability and strength characteristics of urethane-grouted sand AU - Lowther, J. AU - Gabr, M. A. C2 - 1997/// C3 - Grouting: Compaction, remediation and testing: Proceedings of sessions sponsored by the Grouting Committee of the Geo-Institute of the American Society of Civil Engineers in conjuction with the Geo-Logan '97 Conference, Logan, Utah, July 16-18, 1997 (Geotechnical special publication; no. 66) CN - TA436 .G46 1997 DA - 1997/// VL - 66 SP - 258-270 PB - New York: American Society of Civil Engineers ER - TY - CHAP TI - Pedestrian impedance on turning movements saturation flow rates: A comparison of simulation, analytical and field observations AU - Rouphail, N. M. AU - Eads, B. T2 - Pedestrian and bicycle research 1997 CN - TE7 .H5 no. 1578 PY - 1997/// SP - 56-63 PB - Washington, DC: National Academy Press SN - 0309061687 ER - TY - CONF TI - PVDs zone of influence under vacuum in clayey soil AU - Gabr, M. A. AU - Szabo, D. C2 - 1997/// C3 - In situ remediation of the geoenvironment: Proceedings of the conference sponsored by the Geo-Institute and the Environmental Engineering Division of the American Society of Civil Engineers, Minneapolis, Minnesota, October 5-8, 1997 (Geotechnical special publication; no. 71) CN - TD1030 .I57 1997 DA - 1997/// VL - 66 SP - 449-460 PB - Reston, VA: American Society of Civil Engineers ER - TY - CONF TI - New evidence concerning the shock-induced chemical reaction mechanism in a Ni/Al mixture AU - Yang, Y. AU - Gould, R. D. AU - Horie, Y. AU - Iyer, K. R. C2 - 1997/// C3 - Shock compression of condensed matter--1997: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter held at Amherst, Massachusetts, July 27-August 1, 1997 CN - QC173.4.C65 A43 1997 DA - 1997/// VL - 429 SP - 639-642 ER - TY - CONF TI - Mechanistic evaluation of fatigue damage growth and healing of asphalt concrete: Laboratory and field experiments AU - Kim, Y. R. AU - Lee, H. J. AU - Kim, Y. AU - Little, D. N. C2 - 1997/// C3 - Eighth International Conference on Asphalt Pavements, August 10-14, 1997, Seattle, Washington: Proceedings. CN - TE266 .I58 1997 DA - 1997/// SP - 1089-1108 PB - Seattle, Wash.: University of Washington ER - TY - BOOK TI - Mapping erosion hazard areas in Brunswick and Dare counties: Final project report DA - 1997/// PY - 1997/// PB - Raleigh, NC: DEHNR ER - TY - CHAP TI - In-situ evaluation of fatigue damage growth and healing of asphalt concrete pavements using stress wave method AU - Kim, Y. AU - Kim, Y. R. T2 - Pavement rehabilitation and design AB - Accurate in situ evaluation of the changes in material properties of an asphalt surface layer due to fatigue loading and rest periods is important for a better understanding of fatigue mechanisms of asphalt concrete in the field and therefore more realistic prediction of the fatigue life of asphalt pavements. A nondestructive technique based on the stress wave propagation method is presented as a means of measuring the changes in the “apparent” modulus of an asphalt surface layer due to fatigue damage growth and healing during rest periods. The method was applied to four asphalt pavements in the FHWA Turner Fairbank Highway Research Center that were loaded by the Accelerated Loading Facility to induce fatigue damage. The dispersion analysis is performed using the Short Kernel Method on the wave transients measured at different loading cycles and after rest periods. The results indicate that ( a) the test and analysis technique used provides a sensitive means of evaluating the changes in asphalt surface layer properties during fatigue loads and rest periods, ( b) the elastic modulus of the asphalt layer decreases as the number of loading cycles increases in an S-shape decaying curve, and ( c) the effective modulus of the asphalt layer increases because of the introduction of rest between loading cycles. CN - TE7 .H5 no. 1568 PY - 1997/// DO - 10.3141/1568-13 SP - 106-113 PB - Washington, DC: National Academy Press SN - 0309059747 ER - TY - BOOK TI - ITS integration of real-time emissions data and traffic management systems AU - Rouphail, N. M. AU - al., DA - 1997/// PY - 1997/// PB - Transportation Research Board ER - TY - CHAP TI - Generalized delay model for signalized intersections and arterials AU - Fambro, D. AU - Rouphail, N. T2 - Highway capacity issues and analysis CN - TE7 .H5 no. 1572 PY - 1997/// SP - 112-121 PB - Washington, DC: National Academy Press SN - 0309061504 ER - TY - CONF TI - Equipment mounted buried utility detection system AU - Lorenc, S. J. AU - Bernold, L. E. C2 - 1997/// C3 - Proceedings of the ANS Seventh Topical Meeting on Robotics and Remote Systems: April 27 to May 1, 1997 CN - TK9151.6 .A57 1997 DA - 1997/// SP - 169-175 ER - TY - CHAP TI - Design and construction of concrete formwork AU - Johnston, D. W. T2 - Concrete construction engineering handbook CN - TA681 .C743 1997 PY - 1997/// SP - 7.1-740 PB - Boca Raton, Fla.: CRC Press ER - TY - CONF TI - Compaction grouting AU - Borden, R. H. C2 - 1997/// C3 - Ground improvement, ground reinforcement, ground treatment: Developments 1987-1997; Proceedings of sessions sponsored by the Committee on Soil Improvement and Geosynthetics of the Geo-Institute of the American Society of Civil Engineers in conjunction with Geo-Logan '97, Logan, Utah, July 17-19, 1997 CN - TA710.A1 G66 1997 DA - 1997/// SP - 34-45 PB - New York: American Society of Civil Engineers ER - TY - CHAP TI - Characteristics and performance of prefabricated vertical drains for enhanced soil flushing AU - Quaranta, J. AU - Gabr, M. A. AU - Szabo, D. AU - Bowders, J. J. T2 - Pavements and structures monitoring, pavement instrumentation, and drainage systems evaluation AB - The use of prefabricated vertical drains (PVDs) under vacuum conditions for soil flushing was investigated with soils consisting of 100 percent sand or a combination of 80 percent sand and 20 percent kaolinite. Tests of the 100 percent sand specimens indicated that the areal extent of the PVD zone of influence remained approximately 16 to 21 times the PVD-equivalent diameter (PVD circumference/π) as the extraction vacuum increased from 2.5 to 20 kPa. Tests of the sand kaolinite specimens (80/20 soil) indicated that the areal extent of the PVD zone of influence remained approximately 5 to 8 times the PVD equivalent diameter as the extraction vacuum increased from 2.5 to 20 kPa. The effective zone of influence in the 80/20 soil did not show a corresponding increase in areal extent as the vacuum pressure was increased beyond the PVD embedment depth. Pilot-scale tracer flushing tests demonstrated the feasibility of using PVDs for flushing 100 percent sand soil. The tracer testing demonstrated that longer flushing times were necessary to achieve 80 percent cleanup levels as the dry unit weights of soil increased from 1.57 to 1.67 g/cm 3 . The ratio of final to initial concentration reached 0.2 after flushing of the 1.57 g/cm 3 soil for approximately 40 minutes. A similar ratio was reached after flushing of the 1.67 g/cm 3 soil for 50 minutes. PY - 1997/// DO - 10.3141/1596-14 VL - 1596 SP - 93–100 PB - Washington, DC: National Academy Press SN - 0309061733 ER - TY - JOUR TI - Buckling of Piles with General Power Distribution of Lateral Subgrade Reaction AU - Gabr, M. A. AU - Wang, J. J. AU - Zhao, M. T2 - Journal of Geotechnical and Geoenvironmental Engineering AB - A model for evaluating the critical buckling capacity of long slender friction piles is developed with lateral soil support included based on the concept of the subgrade reaction. A general power distribution of the coefficient of the subgrade reaction (kh), with depth, is utilized in the model. The lateral force-deflection (P-y) behavior is assumed to be linear. A parametric study was conducted to demonstrate the effect of ω value, defining the distribution of the horizontal subgrade reaction, on the evaluated buckling capacity. In the case of the free top and fully embedded condition with embedment length (h) greater than 10 m, a 59% increase in the buckling capacity (Pcr) was predicted as ω was increased from 0 (constant horizontal subgrade reaction distribution) to 1 (linearly increasing horizontal subgrade reaction). Results also indicated that the boundary conditions at the pile tip have a minimal effect on Pcr when the nondimensional embedded length (h′) exceeded 3.3 for the free top, 5.6 for the fixed-sway top, and 7.6 for the pinned-top condition. A comparison between a pile load test result reported in the literature and the model presented in this paper favorably verified the applicability of the developed model. DA - 1997/2// PY - 1997/2// DO - 10.1061/(asce)1090-0241(1997)123:2(123) VL - 123 IS - 2 SP - 123-130 ER - TY - CONF TI - An argument in favor of specifications containing grouted soil strength tests at multiple strain rates AU - Borden, R. H. C2 - 1997/// C3 - Grouting: Compaction, remediation and testing: Proceedings of sessions sponsored by the Grouting Committee of the Geo-Institute of the American Society of Civil Engineers in conjuction with the Geo-Logan '97 Conference, Logan, Utah, July 16-18, 1997 (Geotechnical special publication; no. 66) CN - TA436 .G46 1997 DA - 1997/// SP - 173-187 PB - New York: American Society of Civil Engineers ER - TY - CHAP TI - A simplified procedure for prediction of asphalt pavement subsurface temperatures based on heat transfer theories AU - Shao, L. AU - Park, S. AU - Kim, Y. R. T2 - Pavement rehabilitation and design AB - Surface deflection measurements and backcalculation of layer moduli in flexible pavements are significantly affected by the temperature of the asphalt concrete (AC) layer. Correction of deflections or backcalculated moduli to a reference temperature requires determination of an effective temperature of the AC layer. For routine deflection testing and analysis in state highway agencies, it is preferable, from a practical point of view, to use a nondestructive prediction method for determining the effective AC layer temperature instead of measuring the temperature directly from a small hole drilled into the AC layer. A simplified procedure to predict asphalt pavement subsurface temperatures is presented. The procedure is based on fundamental principles of heat transfer and uses the surface temperature history since yesterday morning to predict the AC layer mid-depth temperature at the time of falling weight deflectometer (FWD) testing today. The surface temperature history is determined using yesterday’s maximum air temperature and cloud condition, the minimum air temperature of today’s morning, and surface temperatures measured during FWD tests. FWD tests and temperature measurements have been conducted on seven pavement sections with varying structural designs located in three different climatic regions of North Carolina. The field temperature records from these pavements have provided values of pavement thermal parameters and coefficients in temperature functions that are needed in the prediction procedure. A set of verification results are presented using examples with different climatic regions, changing AC layer thicknesses, and varying weather patterns in different seasons. CN - TE7 .H5 no. 1568 PY - 1997/// DO - 10.3141/1568-14 SP - 114-123 PB - Washington, DC: National Academy Press SN - 0309059747 ER - TY - CONF TI - Proposed revisions to Highway Capacity Manual chapter 9: Pedestrian and bicycle analysis procedures AU - Milazzo, J. AU - Rouphail, N. AU - Allen, P. AU - Hummer, J. C2 - 1997/// C3 - Proceedings of the ASCE Specialty Conference: Traffic Congestion and Safety in the 21st Century, Chicago, IL, June 8-11, 1997 CN - HE336.C64 T697 1997 DA - 1997/// ER - TY - CHAP TI - Performance characteristics of asphalt concrete mixes containing conventional and modified asphalt binders AU - Tayebali, A. A. AU - Harvey, J. T. AU - Tanco, A. AU - Doty, R. N. AU - Monismith, C. L. T2 - Asphalt science and technology CN - TP692.4.A8 A68 1997 PY - 1997/// SP - 479-503 PB - New York, NY: Marcel Dekker, Inc. ER - TY - JOUR TI - Influence of binder loss modulus on the fatigue performance of asphalt concrete pavements T2 - Journal of the Association of Asphalt Paving Technologists DA - 1997/// PY - 1997/// VL - 66 IS - 1997 SP - 633-685 ER - TY - CHAP TI - Generating efficient watershed management strategies using a genetic algorithms-based method AU - Harrell, L. J. AU - Ranjithan, S. T2 - Aesthetics in the constructed environment: Proceedings of 24th Annual Water Resources Planning and Management Conference Houston, Texas, April 6-9, 1997 CN - TC409 .W3692 1997 PY - 1997/// SP - 272-277 PB - New York: American Society of Civil Engineers ER - TY - CONF TI - Effect of crumb rubber particle size and concentration on performance grading of rubber modified asphalt binders progress of superpave (superior performing asphalt pavement): Evaluation and implementation AU - Tayebali, A. A. AU - Vyas, B. B. AU - Malpass, G. C2 - 1997/// C3 - Progress of superpave (superior performing asphalt pavement): Evaluation and implementation (ASTM special technical publication; 1322) DA - 1997/// VL - 1322 SP - 30-47 PB - West Conschocken, PA: ASTM ER - TY - CONF TI - Biodegradation of polycaprolactone in a simulated landfill AU - Ress, B. B. AU - Sanchez, M. R. AU - Pettigrew, C. A. AU - Barlaz, M. A. C2 - 1997/// C3 - Annual Meeting of the Bio/Environmentally Degradable Polymer Society, San Diego, CA, Sept. 16 - 20, 1997 DA - 1997/// ER - TY - JOUR TI - Anaerobic biodegradation of alkylbenzenes in laboratory microcosms representing ambient conditions AU - Hunt, M. J. AU - Shafer, M. B. AU - Barlaz, Morton AU - Borden, R. C. T2 - Bioremediation Journal AB - Abstract A microcosm study was performed to document the anaerobic biodegradation of benzene, toluene, ethylbenzene, m- xylene, and/or o-xylene in petroleum-contaminated aquifer sediment from sites in Michigan (MI) and North Carolina (NC) and relate the results to previous field investigations of intrinsic bioremediation. Laboratory microcosms, designed to simulate ambient conditions, were constructed under anaerobic conditions with sediment and groundwater from source, mid-plume, and end-plume locations at each site. The general patterns of biodegradation and electron acceptor utilization in the microcosms were consistent with field data. At the MI site, methane was produced after a moderate lag period, followed by toluene degradation in all sets of microcosms. At the NC site, biodegradation of the target compounds was not evident in the source area microcosms. In the mid-plume microcosms, toluene and o-xylene biodegraded first, followed by m-xylene and benzene, a pattern consistent with contaminant decay along the plume length. Chemical extraction of microcosm sediment at the beginning and end of me incubation indicated that iron-reducing conditions were dominant and iron reduction occurred on a sediment fraction not extracted by 0.5N HC1. In the end-plume microcosms, degradation of benzene, toluene, and xylene isomers occurred but was variable between replicates. Consistent with field data, dissolved concentrations of the target contaminant(s) persisted at low but detectable levels (0.05 to 0.25 μM) in microcosms from both sites where biodegradation was measured. DA - 1997/// PY - 1997/// DO - 10.1080/10889869709351317 VL - 1 IS - 1 SP - 53–64 ER - TY - CONF TI - A reliability-based mix design and analysis system for mitigating fatigue distress C2 - 1997/// C3 - Eighth International Conference on Asphalt Pavements, August 10-14, 1997, Seattle, Washington: Proceedings. CN - TE266 .I58 1997 DA - 1997/// SP - 301-324 PB - Seattle, Wash.: University of Washington ER - TY - CONF TI - Variability and uncertainty in highway vehicle emission factors AU - Frey, H. C. C2 - 1997/// C3 - Emission inventory: Planning for the future, proceedings of a specialty conference, October 28-30, 1997, Research Triangle Park, NC CN - [Not currently held by TRLN member libraries] DA - 1997/// M1 - 1997 Oct. PB - Pittsburgh, Pa.: Air & Waste Management Association ER - TY - CONF TI - Spatially-integrated robotic excavation and pipelaying AU - Bernold, L. E. AU - Huang, X. C2 - 1997/// C3 - Proceedings of the ANS Seventh Topical Meeting on Robotics and Remote Systems: April 27 to May 1, 1997 CN - TK9151.6 .A57 1997 v.2 DA - 1997/// VL - 2 SP - 856-861 ER - TY - CONF TI - Quantification of variability and uncertainty in AP-42 emission factors using bootstrap simulation AU - Rhodes, D. S. AU - Frey, H. C. C2 - 1997/// C3 - Emission inventory: Planning for the future, proceedings of a specialty conference, October 28-30, 1997, Research Triangle Park, NC CN - [Not currently held by TRLN member libraries] [Earlier years in print form-Hill TD884.A52] DA - 1997/// M1 - 1997 Oct. PB - Pittsburgh, Pa.: Air & Waste Management Association ER - TY - CONF TI - Probabilistic methodology for risk assessment of new energy technologies and application to gasification repowering for an oil refinery in Poland AU - Frey, H. C. AU - Iwanski, Z. A2 - G. Manfrida, A2 - Lior, N. C2 - 1997/// C3 - Florence World Energy Research Symposium (1997): FLOWERS ''97: Florence World Energy Symposium CN - TK1001 .A3 [Hill] DA - 1997/// VL - 39 SP - 267-274 M1 - 16/18 PB - Padova, Italy: SGEditorial ER - TY - BOOK TI - Probabilistic evaluation of mobile source air pollution. Volume I, Probabilistic modeling of exhaust emissions from light duty gasoline vehicles AU - Kini, M. D. AU - Frey, H. C. DA - 1997/// PY - 1997/// PB - Raleigh, NC: North Carolina State University for Center for Transportation and the Environment ER - TY - CONF TI - Methods for characterizing and managing technological risks in advanced power generation systems: Application to gasification repowering in Poland AU - Frey, H. C. AU - Iwanski, Z. C2 - 1997/// C3 - Proceedings of Gasification Technologies Conference, Electric Power Research lnstitute, Palo Alto, CA. October 1997 DA - 1997/// M1 - 1997 Oct. ER - TY - CONF TI - Influence of fines content on the behavior of compaction grout AU - Borden, R. H. AU - Ivanetich, K. B. C2 - 1997/// C3 - Grouting: Compaction, remediation and testing: Proceedings of sessions sponsored by the Grouting Committee of the Geo-Institute of the American Society of Civil Engineers in conjuction with the Geo-Logan '97 Conference, Logan, Utah, July 16-18, 1997 (Geotechnical special publication; no. 66) CN - TA436 .G46 1997 DA - 1997/// SP - 62-75 PB - New York: American Society of Civil Engineers ER - TY - CONF TI - An excavator mounted unexploded ordnance locating system AU - Lorenc, S. J. AU - Bernold, L. E. C2 - 1997/// C3 - Proceedings of the US DoD Global Conference on Unexploded Ordnance UXO Forum '97, Nashville, TN, May 28-30 DA - 1997/// SP - 404-414 M1 - 1997 ER - TY - CONF TI - Urethane grout for barrier formation in sand AU - Gabr, M. A. AU - Freshwater, J. S. C2 - 1997/// C3 - Soil mechanics and foundation engineering, fourteenth international conference: Proceedings of the Fourteenth International Conference on Soil Mechanics and Foundation Engineering, Hamburg Germany, Sept. 1997 DA - 1997/// VL - 14 SP - 1903-1906 ER - TY - CONF TI - The Neighborhood Constraint Method: A genetic algorithm-based multiobjective optimization technique AU - Loughlin, D. H. AU - Ranjithan, S. C2 - 1997/// C3 - Genetic algorithms: Proceedings of the Seventh International Conference on Genetic Algorithms, East Lansing, Michigan, July 19-23, 1997 CN - QA76.618 .I58 1997 DA - 1997/// VL - 7 SP - 666-673 PB - San Francisco, Calif.: M. Kaufmann ER - TY - CONF TI - Shock-wave initiation of chemical reactions in inorganic powders AU - Horie, Y. AU - Yano, K. AB - A new estimate of the threshold condition is proposed for shock-induced chemical reactions in inorganic powder mixtures. The condition is based on a concept of energy balance whereby a sudden increase in interface areas is equated to fluctuating local kinetic energy. Estimates based on the analysis for Ni/Al and Ti/Si compare well with recent real time measurements. C2 - 1997/// C3 - Proceedings of AIRAPT-16 & HPCJ-38, Kyoto, August, 1997 DA - 1997/// DO - 10.4131/jshpreview.7.864 M1 - 1997 Aug. ER - TY - CONF TI - Inclusion of fuzzy variables in geotechnical risk analysis AU - Rahman, M. S. AU - El-Zahaby, K. E. C2 - 1997/// C3 - Computer methods and advances in geomechanics: Proceedings of the Ninth International Conference of the Association for Computer Methods and Advances in Geomechnics: Wuhan, China, 2-7 November, 1997 DA - 1997/// VL - 9 SP - 567-572 M1 - 1997 ER - TY - BOOK TI - High-pressure shock compression of solids IV: Response of highly porous solids to shock loading AU - Davison, L. W. AU - Horie, Y. AU - Shainpoor, M. CN - TA417.7.C65 H553 1997 DA - 1997/// PY - 1997/// PB - New York: Springer-Verlag SN - 038794995X ER - TY - CONF TI - Dune morphology from photogrammetry-derived digital terrain models AU - Judge, E. K. AU - Garriga, C. M. AU - Overton, M. F. C2 - 1997/// C3 - American Geophysical Union Annual Fall Meeting, San Francisco, CA., 1997 DA - 1997/// ER - TY - BOOK TI - CREST-IRS: A computer program for generating instructure response spectra (Version 1.0) AU - Gupta, A. AU - Gupta, A. K. DA - 1997/// PY - 1997/// PB - Center for Nuclear Power Plant Structures, Equipment and Piping in the Department of Civil Engineering ER - TY - CHAP TI - User preferences of flourescent strong yellow-green pedestrian crossing sign AU - Dutt, N. AU - Hummer, J. E. AU - Clark, K. L. T2 - Research on traffic control devices CN - TE7 .H5 no. 1605 PY - 1997/// SP - 17-21 PB - Washington, DC: Transportation Research Board SN - 0309061741 ER - TY - CONF TI - Stress fluctuation and order generation in shearing of granular materials AU - Schwarz, O. J. AU - Horie, Y. A2 - S. C. Schmidt, D. P. Dandekar A2 - Forbes, J. W. C2 - 1997/// C3 - Proceedings of the Conference of the American Physical Society Topical Conference on Shock Compression of Condensed Matter held at Amherst, Massachusetts, July 27-August 1, 1997 CN - QC173.4.C65 A43 1997 DA - 1997/// VL - 429 SP - 263-266 ER - TY - CHAP TI - Planning and engineering studies AU - Hummer, J. E. T2 - Traffic sign handbook (Ch. 4) PY - 1997/// PB - Washington, DC: Institute of Transportation Engineers ER - TY - CONF TI - Particle velocity dispersion in shock compression of solid mixtures AU - Yano, K. AU - Horie, Y. A2 - S. C. Schmidt, D. P. Dandekar A2 - Forbes, J. W. C2 - 1997/// C3 - Proceedings of the Conference of the American Physical Society Topical Conference on Shock Compression of Condensed Matter held at Amherst, Massachusetts, July 27-August 1, 1997 CN - QC173.4.C65 A43 1997 DA - 1997/// VL - 429 SP - 259-262 ER - TY - CHAP TI - Landside access to sea ports in urban areas: A case study AU - Chatterjee, A. AU - Hummer, J. E. AU - Clarke, D. B. AU - Ney, S. M. T2 - Truck, marine, and intermodal freight and hazardous materials transportation CN - TE7 .H5 no. 1602 PY - 1997/// SP - 49-56 PB - Washington, DC: Transportation Research Board SN - 0309062047 ER - TY - CONF TI - Discrete element modeling of shock compression of hBN powder with and without copper addition AU - Horie, Y. AU - Yano, K. C2 - 1997/// C3 - Proceedings of the International Workshop on Industrial Applications of Explosion, Shock-Wave and High Pressure Phenomena. Kumamoto, October 1997 DA - 1997/// M1 - 1997 ER - TY - CONF TI - Collision factors and potential counter measures related to heavy trucks on two-lane roads AU - Hummer, J. E. AU - Khattak, A. AU - Kantor, P. C2 - 1997/// C3 - Proceedings, 1997 International Large Truck Safety Symposium, Knoxville, TN, October 27-29 DA - 1997/// SP - 81-91 M1 - 1997 ER - TY - CONF TI - A new computer code DM2: Discrete meso-dynamic modeling of shock processes in solids AU - Horie, Y. AU - Yano, K. C2 - 1997/// C3 - New models and numerical dodes for shock wave processes in condensed media: Proceedings of the International Workshop held at Oxford, 15-19 September 1997 DA - 1997/// M1 - 1997 ER - TY - CONF TI - A computer-controlled multipurpose bridge maintenance robotic system AU - Zhang, T. AU - Lorenc, S. J. AU - Bernold, L. E. AU - Lee, G. K. C2 - 1997/// C3 - Computer applications in industry and engineering: Proceedings of the ISCA 10th international conference, San Antonio, Texas, U.S.A., December 10-12, 1997 CN - QA76.76.A65 C657 1997 DA - 1997/// SP - 90-93 PB - Cary, NC: ISCA ER - TY - CHAP TI - Telerobotics for infrastructure maintenance: Safe raised pavement-marker application AU - Rihani, R. A. AU - Bernold, L. E. T2 - Safety and management in maintenance and construction operations CN - TE7 .H5 no. 1585 PY - 1997/// SP - 48-52 PB - Washington, DC: Transportation Research Board SN - 0309061563 ER - TY - JOUR TI - Operator-interfaced intelligent path planning for robotic bridge paint removal AU - Moon, S.-W. AU - Bernold, L. E. T2 - Journal of Computing in Civil Engineering DA - 1997/// PY - 1997/// VL - 2 IS - 2 SP - 113-120 ER - TY - JOUR TI - On-line assistance for crane operators AU - Bernold, L. E. AU - Lorenc, S. J. AU - Luces, E. T2 - Journal of Computing in Civil Engineering DA - 1997/// PY - 1997/// VL - 2 IS - 4 SP - 248-259 ER - TY - CHAP TI - Collection and presentation of roadway inventory data AU - Karimi, H. A. AU - Hummer, J. E. T2 - Interim Report, National Cooperative Highway Research Program Project 1515, Transportation Research Board, Washington, DC, May 1997 PY - 1997/// PB - Washington, DC: Transportation Research Board ER - TY - JOUR TI - CAD-integrated excavation and pipe laying AU - Huang, X. AU - Bernold, L. T2 - Journal of Construction Engineering and Management AB - Excavation and, in particular, trenching using backhoes represents a hazardous working environment for workers. The hazards include trench walls that collapse, the accidental drop of heavy objects into the opening, excavators and other equipment that become unstable, and buried utilities that are damaged during the operation. The three main accident prevention efforts used today are the use of the trench box, inspection, and the training of the site personnel. The work discussed in this paper is the result of a search for a more revolutionary prevention method: one that does not require a worker to enter the open trench. This paper presents the development and testing of a computer-aided design (CAD) integrated trenching and pipe-laying system. The successful testing of the first prototype could lay the foundation for safer and more productive trenching operations in the future. DA - 1997/// PY - 1997/// DO - 10.1061/(ASCE)0733-9364(1997)123:3(318) VL - 123 IS - 3 SP - 318-323 ER - TY - CHAP TI - Bicycle operations and level of service literature synthesis AU - Rouphail, N. M. AU - Hummer, J. E. AU - Allen, D. P. T2 - Final Draft, Federal Highway Administration, McLean, VA, January 1997 PY - 1997/// ER - TY - JOUR TI - An adaptive neural network impedance learning control method for robotic systems AU - Huang, X AU - Bernold, L. E. T2 - Journal of the Chinese Society of Mechanical Engineers DA - 1997/// PY - 1997/// VL - 19 IS - 1 SP - 61-88 ER - TY - CONF TI - A comparative study of performance of different designs for flexible pavements AU - Khosla, N. P. AU - Satish, S. AU - Kim, N. AU - Kim, Y. R. C2 - 1997/// C3 - Eighth International Conference on Asphalt Pavements, August 10-14, 1997, Seattle, Washington: Proceedings. CN - TE266 .I58 1997 DA - 1997/// SP - 328-335 PB - Seattle, Wash.: University of Washington ER - TY - CONF TI - The effect of robotic brick placement on bond strength AU - Rihani, R. AU - Lorenc, S. J. AU - Bernold, L. E. C2 - 1997/// C3 - Proceedings of the 14th International Symposium on Automation & Robotics in Construction, Pittsburgh, Pennsylvania, June 8-11 DA - 1997/// SP - 269-276 M1 - 1997 ER - TY - CONF TI - Development of a robotic bridge maintenance system AU - Lorenc, S. J. AU - Handlon, B. E. AU - Bernold, L. E. C2 - 1997/// C3 - Proceedings of the Fourteenth International Symposium on Automation & Robotics in Construction, Pittsburgh, Pennsylvania, June 8-11, 1997 DA - 1997/// SP - 432-436 M1 - 1997 ER - TY - JOUR TI - Classifying unlighted roadways based on night to total accident ratios AU - Hummer, JE AU - Graham, , JR AU - Ravoori, SB AU - King, LE AU - Rogers, MD T2 - JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY DA - 1997/// PY - 1997/// DO - 10.1080/00994480.1997.10748190 VL - 26 IS - 2 SP - 49-+ SN - 0099-4480 ER - TY - JOUR TI - Micromechanical tensile behavior of slurry infiltrated continuous-fiber-mat reinforced concrete (SIMCON) AU - Krstulovic-Opara, N. AU - Malak, S. T2 - ACI Materials Journal DA - 1997/// PY - 1997/// VL - 94 IS - 5 SP - 373-384 ER - TY - JOUR TI - Integrated environmental control modeling of coal-fired power systems AU - Rubin, ES AU - Kalagnanam, , JR AU - Frey, HC AU - Berkenpas, MB T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - Abstract The capability to estimate the performance and costs of advanced environmental control systems for coal-fired power plants is critical to a variety of planning and analysis requirements faced by utilities, regulators, researchers, and analysts in the public and private sectors. This paper describes a computer model developed for the U.S. Department of Energy (DOE) to provide an up-to-date capability for analyzing a variety of pre-combustion, combustion, and post-combustion options in an integrated framework. A unique feature of the model allows performance and costs of integrated environmental control concepts to be modeled probabilistically as a means of characterizing uncertainties and risks. Examples are presented of model applications, comparing conventional and advanced emission control designs. The magnitude of technological risks associated with advanced technologies now under development are seen to vary markedly across applications. In general, however, integrated environmental control concepts show significant potential for more cost-effective methods of emissions control. DA - 1997/11// PY - 1997/11// DO - 10.1080/10473289.1997.10464063 VL - 47 IS - 11 SP - 1180-1188 SN - 1047-3289 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031282206&partnerID=MN8TOARS ER - TY - CHAP TI - Effluent charges and transferable discharge permits AU - Brill, E. D. T2 - Design and operation of civil and environmental engineering systems A2 - C. ReVelle, A2 - McGarity, A. E. CN - TA153 .D47 1997 PY - 1997/// SP - 657-690 PB - New York: Wiley ER - TY - JOUR TI - The pretreatment of acrylonitrile and styrene with the ozonation process AU - Chang, CN AU - Lin, JG AU - Chao, AC AU - Cho, BC AU - Yu, RF T2 - WATER SCIENCE AND TECHNOLOGY AB - Acrylonitrile and styrene are used as the raw materials for manufacturing acrylic fiber, thus they are often found as pollutants in the petrochemical wastewater. This study utilizes ozone to decompose the organic nitrogen contained in acrylonitrile and styrene, and the oxidation process was monitored using on-line measurements of oxidation-reduction potential (ORP) and pH. The efficiency of organic nitrogen decomposition was also estimated based on the COD, organic nitrogen, TOC, ammonia-N, nitrite, and nitrate measurements. Both the initial pH and alkalinity are observed to affect the degradation rate of organic nitrogen. The acrylonitrile sample with the lowest initial pH value (i.e., 4.0) has a shorter t1/2 of 18.9 min and that for samples of the highest initial pH (i.e., 11) was 34 min. The alkalinity of one acrylonitrile sample was boosted by adding 500 mg/l CaCO3, to simulate the field ABS (Acrylonltrde-Butadiene-Styrene) wastewater effluent. It was observed that within a short ozone contact time, the acrylonitrile sample spiked with 500 mg/l CaCO3 had the highest COD decomposition rate of 0.411 mm−1, or 1.3 times more than that for samples without addition of CaCO3. Results of the ozonation process can be fitted with a modified Nernst equation for the various pH conditions. Additionally, the ozone treated synthetic ABS sample shows a faster COD removal rate in the subsequent biological process than those samples without ozone treatment. DA - 1997/// PY - 1997/// DO - 10.1016/S0273-1223(97)00396-X VL - 36 IS - 2-3 SP - 263-270 SN - 0273-1223 KW - ABS KW - acrylonitrile KW - acrylic fiber KW - Nernst equation KW - ORP KW - ozonation KW - petrochemical KW - styrene ER - TY - JOUR TI - Pullout behavior of steel fibers from cement-based composites AU - Shannag, MJ AU - Brincker, R AU - Hansen, W T2 - CEMENT AND CONCRETE RESEARCH AB - A comprehensive experimental program on pullout tests of steel fibers from cement based matrices is described. A specially designed single fiber pullout apparatus was used to provide a quantitative determination of interfacial properties that are relevant to toughening brittle materials through fiber reinforcement. The parameters investigated included a specially designed high strength cement based matrix called Densified Small Particles system (DSP), a conventional mortar matrix, fiber embeddment length, and the fiber volume fraction. The mediums from which the fiber was pulled included a control mortar mix without fibers, a mortar mix with 3, and 6 percent fibers by volume. The results indicate that: (1) The dense DSP matrix has significantly improved interfacial properties as compared to the conventional mortar matrix. (2) Increasing the fiber embeddment length and the fiber volume fraction in the cement matrix increase the peak pullout load and the pullout work. (3) The major bond mechanism in both systems is frictional sliding. DA - 1997/6// PY - 1997/6// DO - 10.1016/S0008-8846(97)00061-6 VL - 27 IS - 6 SP - 925-936 SN - 0008-8846 ER - TY - JOUR TI - Intelligent technology for truck crane accident prevention AU - Bernold, L. E. AU - Lorenc, S. J. AU - Luces, E. T2 - Journal of Construction Engineering and Management AB - Sideand shock-loading of cranes can cause boom and turret drive gear failures with fatal results. However, traditional overload systems do not protect against these types of critical loading conditions, and crane capacity charts only consider the normal loading case, vertical lifts. In the maintenance of bridges, crane operators in any state department of transportation are presented with situations in which they have to pull debris and entire trees that are lodged against bridges. Dragging and shock-loading are commonplace. Researchers from the Construction Automation and Robotics Laboratory at North Carolina State University have developed an innovative crane monitoring system capable of warning an operator who enters a danger zone and storing information about critical events on an electronic device. Acting like a black box on an airplane, the storage device allows this information to be downloaded by a supervisor in order to assess how a particular crew “worked” the crane. This paper presents the results of this project and discusses the basic components of the accident prevention system for cranes. DA - 1997/// PY - 1997/// DO - 10.1061/(ASCE)0733-9364(1997)123:3(276) VL - 123 IS - 3 SP - 276-284 ER - TY - JOUR TI - Analytical and numerical investigation of non-uniform straining and subgrain initiation in bicrystals in channel die compression AU - Wu, SC AU - Havner, KS T2 - PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES AB - Effects of the grain boundary (i.e. interface plane) on deformation and stress state in symmetric FCC bicrystals are investigated. The full range of lattice constraint directions for crystals compressed in a (110) direction within a rigid channel die is considered. The spatial non–uniformity is only two dimensional and in the plane transverse to the loading direction. Principal analytical results are that subgrains begin to form within each crystal and tangential velocity discontinuities extend from interface edges in characteristic directions which depend on crystal orientation. Numerical (finite element) results for several orientations at the end of the elastoplastic transition form purely elastic to fully plastic (multiple–slip) response are compared with the analytical rigid–plastic solutions. Both analytical and numerical results predict subranges of lattice orientations in which there is separation of crystal and channel wall. DA - 1997/9/15/ PY - 1997/9/15/ DO - 10.1098/rsta.1997.0095 VL - 355 IS - 1730 SP - 1905-1943 SN - 1364-503X ER - TY - JOUR TI - A viscoelastic constitutive model for particulate composites with growing damage AU - Park, SW AU - Schapery, RA T2 - INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES AB - A mechanical model which describes time-and temperature-dependent deformation behavior of particulate composites with changing microstructure, including growing damage, is described and then verified by experimental study of a viscoelastic filled elastomer. An existing constitutive model, which is based upon thermodynamics of irreversible processes with internal state variables, is first reviewed and then used to describe the mechanical behavior of elastic and viscoelastic media with changing microstructure. A rate-type equation is successfully employed in describing the evolution of microstructural changes, which are believed here to be primarily microcracking. An elastic-viscoelastic correspondence principle and the time-temperature superposition principle are used in modeling effects of the material's intrinsic viscoelasticity and the effects of temperature changes. Laboratory tests of the stress and dilatation responses of uniaxial test specimens under controlled monotonically increasing axial extension and constant confining pressure at different temperatures were performed. The effects of strain level, strain rate, confining pressure, and temperature on the stress and dilatation are described and compared to the theoretical model. DA - 1997/3// PY - 1997/3// DO - 10.1016/S0020-7683(96)00066-2 VL - 34 IS - 8 SP - 931-947 SN - 0020-7683 ER - TY - JOUR TI - Purity and yield of beta-lactoglobulin isolated by an N-retinyl-Celite bioaffinity column AU - Heddleson, RA AU - Allen, JC AU - Wang, QW AU - Swaisgood, HE T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - A bioaffinity column of all-trans-retinal immobilized on Celite was capable of isolating high-purity (94.5%) β-lactoglobulin from bovine acid whey. Conditions for producing a potentially hypoallergenic reduced β-lactoglobulin whey were investigated. Reapplication of pH 5.1 eluate to the column resulted in a final purity of 87% α-lactalbumin. The purity of β-lactoglobulin was slightly lower upon elution with buffers containing <0.4 M sodium phosphate, whereas the yield from desorbing buffers <0.1 M decreased to approximately 40% of that obtained with 0.4 M sodium phosphate. Desorption with low phosphate concentration was improved when pH was increased, suggesting that desorption involves titration of a protophilic group on β-lactoglobulin. These findings suggest that the retinal matrix shows promise in its application for creating hypoallergenic products and the isolation of high-purity β-lactoglobulin with useful functional properties. Keywords: β-Lactoglobulin; α-lactalbumin; bioselective adsorption; N-retinyl-Celite DA - 1997/7// PY - 1997/7// DO - 10.1021/jf9605198 VL - 45 IS - 7 SP - 2369-2373 SN - 0021-8561 KW - beta-lactoglobulin KW - alpha-lactalbumin KW - bioselective adsorption KW - N-retinyl-Celite ER - TY - JOUR TI - Intrinsic biodegradation of MTBE and BTEX in a gasoline-contaminated aquifer AU - Borden, RC AU - Daniel, RA AU - LeBrun, LE AU - Davis, CW T2 - WATER RESOURCES RESEARCH AB - Three‐dimensional field monitoring of a gasoline plume showed rapid decay of toluene and ethylbenzene during downgradient transport with slower decay of xylenes, benzene, and MTBE under mixed aerobic‐denitrifying conditions. Decay was most rapid near the source but slower farther downgradient. Effective first‐order decay coefficients varied from 0 to 0.0010 d −1 for MTBE, from 0.0006 to 0.0014 d −1 for benzene, from 0.0005 to 0.0063 d −1 for toluene, from 0.0008 to 0.0058 d −1 for ethylbenzene, from 0.0012 to 0.0035 d −1 for m‐, p‐xylene, and from 0.0007 to 0.0017 d −1 for o‐xylene. Laboratory microcosm studies confirmed MTBE biodegradation under aerobic conditions; however, the extent of biodegradation was limited. DA - 1997/5// PY - 1997/5// DO - 10.1029/97WR00014 VL - 33 IS - 5 SP - 1105-1115 SN - 1944-7973 ER - TY - JOUR TI - Binding of vitamin D and cholesterol to beta-lactoglobulin AU - Wang, QW AU - Allen, JC AU - Swaisgood, HE T2 - JOURNAL OF DAIRY SCIENCE AB - beta-Lactoglobulin was isolated directly from acidic whey by bioselective adsorption on N-retinyl-Celite, yielding preparations of > or = 96% purity. Interactions of these preparations with vitamin D2, vitamin D3, ergosterol, cholesterol, and 7-dehydrocholesterol were examined by following changes in the fluorescence spectra. Both the excitation and emission spectra indicated that energy was transferred between the tryptophanyl residues of the protein and the chromophore of the ligand. Analyses of the fluorescence changes that occurred upon titration of beta-LG with the various ligands allowed determination of the dissociation constant for the complex and the number of moles bound per mole of protein. The affinity for vitamin D2 (dissociation constant of 4.91 nM) was 10-fold higher than that of the other compounds, except for ergosterol, which was 5-fold larger than the others. Also, the affinity was 10-fold higher than that typically reported for the retinoids. Furthermore, the value obtained for the number of moles bound per mole of protein was 2 mol.mol-1 for each of the ligands examined in this study; it has been well established that all of the retinoids are bound with a stoichiometry of 1.0. These results suggest that beta-LG may be a better carrier of vitamin D than of vitamin A. DA - 1997/6// PY - 1997/6// DO - 10.3168/jds.S0022-0302(97)76030-2 VL - 80 IS - 6 SP - 1054-1059 SN - 0022-0302 KW - beta-lactoglobulin KW - vitamin D binding KW - cholesterol binding KW - bioselective adsorption ER - TY - JOUR TI - Binding of retinoids to beta-lactoglobulin isolated by bioselective adsorption AU - Wang, QW AU - Allen, JC AU - Swaisgood, HE T2 - JOURNAL OF DAIRY SCIENCE AB - Binding of the retinoids, all-trans-retinol, all-trans-retinal, all-trans-retinyl acetate, and all-trans-retinoic acid, to beta-lactoglobulin (LG) (96% purity) that had been prepared by bioselective adsorption on N-retinyl-Celite was determined from changes in the fluorescence quenching (332 nm) of the protein tryptophanyl residues. High affinity binding of all of these compounds occurred at pH 7.0, and the apparent dissociation constant ranged from 1.7 to 3.6 x 10(-8) M. Furthermore, a stoichiometry of 1.0 mol.mol-1 of protein was obtained for each case, indicating that all of the sites in the protein preparation were available. When beta-LG in whey protein isolate (57.4% beta-LG) was studied, a stoichiometry of 0.65 to 0.82 mol.mol-1 of protein was obtained, indicating that a large number of the sites already had bound lipid or that the protein had been denatured. As the pH was lowered toward 5.15, the affinity decreased about fourfold, but the stoichiometry of binding was unchanged. Far UV circular dichroism spectra indicated that the secondary structure of the protein was not significantly affected by ligand binding; however, the near UV spectra were changed, indicating that the flexibility of tryptophanyl residues decreased. The latter effect is consistent with the change in fluorescence quenching and suggests that a tryptophan is in the binding site. DA - 1997/6// PY - 1997/6// DO - 10.3168/jds.S0022-0302(97)76029-6 VL - 80 IS - 6 SP - 1047-1053 SN - 0022-0302 KW - beta-lactoglobulin KW - retinoid binding KW - bioselective adsorption KW - whey protein isolate ER - TY - JOUR TI - Toward a class of link travel time functions for dynamic assignment models on signalized networks AU - Ran, B AU - Rouphail, NM AU - Tarko, A AU - Boyce, DE T2 - TRANSPORTATION RESEARCH PART B-METHODOLOGICAL AB - This paper investigates time-dependent travel time functions for dynamic assignment on signalized arterial network links. Dynamic link travel times are first classified according to various applications. Subsequently, stochastic and deterministic travel time functions for longer and shorter time horizons are discussed separately, and two sets of functions are recommended for dynamic transportation network problems. The implications of those functional forms are analyzed and some modifications for dynamic network models are suggested. In addition, based on dynamic link travel time functions, we discuss how many independent variables are necessary to describe the temporal traffic flow and properly estimate the time-dependent travel time and flow propagation over an arterial link. As a result, six link flow variables and corresponding link state and flow propagation equations are proposed as the basis to formulate dynamic transportation network models. DA - 1997/8// PY - 1997/8// DO - 10.1016/S0191-2615(96)00036-7 VL - 31 IS - 4 SP - 277-290 SN - 0191-2615 ER - TY - PCOMM TI - Solid waste management system analysis with air pollution and leachate impact limitations: comments AU - Harrison, K. W. DA - 1997/// PY - 1997/// SP - 217 ER - TY - JOUR TI - Shear modulus of the interfacial bond between steel fibres and concrete AU - Hamoush, SA AU - Terro, MJ AU - Ahmad, SH T2 - MAGAZINE OF CONCRETE RESEARCH AB - An analytical model for determining the interfacial bond shear modulus of steel-fibre-reinforced concrete is presented. The bond shear modulus is a constant that linearly relates the bond shear stress to the fibre slippage at the interface. The analytical model is developed based on the axisymmetric modelling of the pulled-out steel fibre from the surrounding concrete. The model assumes elastic behaviour for both the concrete and the steel fibres. The analytical model evaluates the total displacement of the fibre when pull-out loads are applied at the fibre end. Experimental analyses are used in conjunction with the analytical model to determine the bond shear modulus. The results of the numerical analysis of a few selected experiments are presented. The proposed model is used to evaluate a constant value for the bond shear modulus. DA - 1997/12// PY - 1997/12// DO - 10.1680/macr.1997.49.181.277 VL - 49 IS - 181 SP - 277-282 SN - 0024-9831 ER - TY - JOUR TI - Methane potential of food waste and anaerobic toxicity of leachate produced during food waste decomposition AU - Wang, YS AU - Odle, WS AU - Eleazer, WE AU - Barlaz, MA T2 - WASTE MANAGEMENT & RESEARCH AB - The objective of this study was to characterize the anaerobic biodegradation of food waste, including its methane potential and the anaerobic toxicity of leachate associated with food waste decomposition. Biodegradation experiments were conducted in 2.2-litre reactors and were seeded with well-decomposed refuse. Despite pH neutralization, reactors seeded with 30% old refuse failed to undergo methanogenesis. Food waste in a second set of reactors, containing 70% seed, produced 300.7 ml CH4dry g−1. Leachate toxicity was evaluated by a modified anaerobic toxicity assay (ATA). The results of ATAs were typically consistent with the methane production behavior of the reactors. However, the toxicity observed in the ATA test could not be simulated with synthetic leachate containing high concentrations of carboxylic acids and sodium. Tests with 20, 5, 15 and 12 g l−1of acetate, propionate, butyrate and sodium, respectively, suggested that high concentrations of butyric acid and sodium inhibited the onset of methane production but that refuse micro-organisms could acclimatize to these concentrations within 5–10 days. The refuse ecosystem was shown to tolerate higher concentrations of undissociated carboxylic acids than previously reported for anaerobic digesters. DA - 1997/4// PY - 1997/4// DO - 10.1006/wmre.1996.0073 VL - 15 IS - 2 SP - 149-167 SN - 0734-242X KW - municipal solid waste KW - refuse KW - methane KW - landfills KW - anaerobic digestion KW - toxicity ER - TY - JOUR TI - Isolation and characterization of refuse methanogens AU - Ladapo, JA AU - Barlaz, MA T2 - JOURNAL OF APPLIED MICROBIOLOGY AB - Four mesophilic, irregular, rod-shaped methanogenic bacteria were isolated from decomposing refuse recovered from laboratory-scale reactors and a municipal solid waste landfill. H2/CO2 was the only substrate on which the isolates could grow in a complex medium. Isolates grew between either 25° or 30° and 45°C and between pH 6 and 8. One isolate exhibited growth at pH 5. Growth of each isolate was enhanced by yeast extract and inhibited by anaerobic sewage sludge supernatant fluid. No isolate showed greater than 25% lysis on exposure to 1% sodium dodecyl sulphate (SDS) for 24 h, as is typical of methanogens with a proteinaceous cell wall. The physiological traits of the methanogens isolated here are similar to many previously characterized isolates. DA - 1997/6// PY - 1997/6// DO - 10.1046/j.1365-2672.1997.00154.x VL - 82 IS - 6 SP - 751-758 SN - 1364-5072 ER - TY - JOUR TI - The effect of preloading on rapid small-scale column test predictions of atrazine removal by GAC adsorbers AU - Knappe, DRU AU - Snoeyink, VL AU - Roche, P AU - Prados, MJ AU - Bourbigot, MM T2 - WATER RESEARCH AB - Rapid small-scale column tests (RSSCTs) were evaluated for their ability to predict atrazine removal in pilot-scale granular activated carbon (GAC) adsorbers. The performance of both virgin and preloaded GACs was tested. Atrazine removal by virgin GAC was studied in post-filter adsorbers at Toulouse, France, and Choisy-le-Roi, France, using empty-bed contact times (EBCTs) of 10.3 and 14 min, respectively. For virgin GAC, RSSCTs successfully simulated atrazine removal over large-scale operating times of about 3.5–7 months. However, RSSCTs significantly overestimated atrazine removal at longer operating times. Atrazine removal by preloaded GAC was studied in pilot-scale post-filter adsorbers at Choisy-le-Roi, France, after preloading times of 5 months and 20 months. EBCTs were approximately 8.5 min. To describe the performance of pilot-scale adsorbers containing preloaded GAC, RSSCTs were initiated with virgin activated carbon, and preloading was simulated prior to the spiking of atrazine. For a pilot-scale adsorber containing GAC that had been preloaded for 5 months, the RSSCT data effectively described atrazine removal. However, the RSSCT was not successful in predicting atrazine removal by GAC after a preloading time of 20 months. Discrepancies between RSSCT and pilot data for long service times or after extended preloading periods may have been due to enhanced adsorption of background organic matter in the presence of oxygen. Overall, RSSCTs were judged to be most useful for predicting the initial performance of adsorbers containing virgin GAC. DA - 1997/11// PY - 1997/11// DO - 10.1016/S0043-1354(97)00148-6 VL - 31 IS - 11 SP - 2899-2909 SN - 0043-1354 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031281636&partnerID=MN8TOARS KW - activated carbon KW - atrazine KW - preloading KW - natural organic matter KW - adsorption KW - rapid small-scale column test KW - drinking water treatment ER - TY - JOUR TI - Systematic evaluation of pollutant removal by urban wet detention ponds: Closure AU - Wu, J. S. AU - Holman, R. E. AU - Dorney, J. R. T2 - Journal of Environmental Engineering (New York, N.Y.) DA - 1997/// PY - 1997/// VL - 123 IS - 11 SP - 1167 ER - TY - JOUR TI - Seismic response of building frames with vertical structural irregularities AU - Valmundsson, E. AU - Nau, J. M. T2 - Journal of Structural Engineering (New York, N.Y.) AB - Earthquake design codes require different methods of analysis for regular and irregular structures, but it is only recently that codes have included specific criteria that define irregular structures. In this paper, the mass, strength, and stiffness limits for regular buildings as specified by the Uniform Building Code (UBC) are evaluated. The structures studied are two-dimensional building frames with 5, 10, and 20 stories. Six fundamental periods are considered for each structure group. Irregularities are introduced by changing the properties of one story or floor. Floor-mass ratios ranging from 0.1 to 5.0 are considered, and first-story stiffness and strength ratios varying from 1.0 to 0.5 are included. The response is calculated for design ductility levels of 1 (elastic), 2, 6, and 10 for four earthquake records. Conclusions are derived regarding the effects of the irregularities on shear forces and maximum ductility demands. It is found that the mass and stiffness criteria of UBC result in moderate increases in response quantities of irregular structures compared to regular structures. The strength criterion, however, results in large increases in response quantities and thus is not consistent with the mass and stiffness requirements. Based on these findings, several modifications to the criteria are proposed, which include a revised formula for estimating the fundamental period for buildings with nonuniform distributions of mass. DA - 1997/// PY - 1997/// DO - 10.1061/(asce)0733-9445(1997)123:1(30) VL - 123 IS - 1 SP - 30-41 ER - TY - JOUR TI - Modeling and evaluation of externally fired combined cycle using ASPEN AU - Agarwal, P. AU - Frey, H. Christopher T2 - Journal of Energy Engineering AB - A new performance model of the externally fired combined cycle (EFCC) is implemented in ASPEN (Advanced System for Process ENgineering), a chemical process simulator. The model accounts for interactions within and between approximately a dozen major process areas. The new model is applied to case studies to evaluate the sensitivity of process performance to the ranges of uncertainty in key model inputs such as heat losses, carbon conversion, and air leakage rates, and to illustrate how alternative designs, including steam injection and flue gas desulfurization (FGD), can affect plant thermal efficiency and net power output. The model results suggest that careful attention to the design of the FGD system is needed, especially with respect to reheat, and that steam injection may offer cost savings associated with reducing the size of the steam turbine with little or no penalty on plant output or plant efficiency. Uncertainties in the slagging combustor and the ceramic heat exchanger may lead to significant penalties on process performance. DA - 1997/// PY - 1997/// DO - 10.1061/(ASCE)0733-9402(1997)123:3(69) VL - 123 IS - 3 SP - 69–87 ER - TY - JOUR TI - Enhanced biodegradation of BTEX in a nutrient briquet-peat barrier system AU - Kao, C.-M. AU - Borden, R. C. T2 - Journal of Environmental Engineering (New York, N.Y.) AB - A two-layer barrier system has been developed to remediate gasoline-contaminated ground water. This system consists of a nutrient briquet layer to continuously supply nitrate as the electron acceptor for contaminant biodegradation and a peat layer to remove residual nitrate via biological denitrification and residual contaminants by sorption. Nitrate release rates from three different sizes of concrete briquets were used to estimate parameters for modeling solute diffusion in aggregated porous media with mobile and stagnant pore-water regions. Toluene, ethylbenzene, and xylene (TEX) biodegradation rates in denitrifying microcosms at pH 8 and 9 were lower than in microcosms at pH 7.4. No degradation was observed at pH 10 under denitrifying conditions. A laboratory-scale, permeable barrier system was developed to evaluate TEX removal and to identify any operational problems. Average removal efficiencies were 86% for toluene, 71% for ethylbenzene, 43% for m-xylene, and 28% for o-xylene in the nutrient briquet and downstream soil column over a 45-day operating period. There was no evidence of benzene biodegradation under denitrifying conditions in the batch microcosms or continuous-flow columns. DA - 1997/// PY - 1997/// DO - 10.1061/(asce)0733-9372(1997)123:1(18) VL - 123 IS - 1 SP - 18-24 ER - TY - JOUR TI - Determination of microturbulence enhanced electron collisionality in magnetized coaxial accelerator channels by direct magnetic field measurement AU - Black, DC AU - Mayo, RM AU - Caress, RW T2 - PHYSICS OF PLASMAS AB - A miniature magnetic probe array, consisting of 10 spatially separated coils, has been used to obtain profile information on the time varying magnetic field within the 2.54 cm wide flow channel of the coaxial plasma source experiment (CPS-1) [R. M. Mayo et al., Plasma Sources Sci. Technol. 4, 47 (1995)]. The magnetic field data have been used, together with a resistive, Hall magnetohydrodynamic (MHD) model of applied field distortion by the flowing plasma, to obtain estimates of the microturbulent enhancement to electron collisionality within the CPS-1 flow channel. These measurements provide direct experimental evidence of anomalous electron collisionality, a previously predicted effect in these devices. The anomaly parameter, a=νan/νcl, determined both from the distortion of contours of constant magnetic flux, and from local Bθ and Bz measurements scales with the classical electron magnetization parameter (Ωcl=ωce/νecl), indicating that collisionality plays a strong role in determining the level of anomalous transport in the plasma. When this anomaly parameter scaling is cast in terms of the ratio νecl/ωlh, it is found that the resistivity enhancement scales with νecl/ωlh, and becomes significant at νecl/ωlh⩽1, suggesting that a lower hybrid drift instability may be the responsible mechanism for enhanced transport. DA - 1997/10// PY - 1997/10// DO - 10.1063/1.872253 VL - 4 IS - 10 SP - 3581-3590 SN - 1089-7674 ER - TY - JOUR TI - Shock-induced chemical reactions in a Ni/Al powder mixture AU - Yang, Y AU - Gould, RD AU - Horie, Y AU - Iyer, KR T2 - APPLIED PHYSICS LETTERS AB - A new 50 mm powder gun was used to reproduce and to extend the real-time observations of ultra-fast exothermic reactions in a Ni/Al powder mixture at the shock front. Shock profiles measured by a manganin gauge show that (1) the threshold pressure for reaction is about 14 GPa; (2) the initiation criteria based either on shock energy or melting are in contradiction with experimental evidence. DA - 1997/6/23/ PY - 1997/6/23/ DO - 10.1063/1.119172 VL - 70 IS - 25 SP - 3365-3367 SN - 1077-3118 ER - TY - JOUR TI - Modeling and verifying active structural control systems AU - Elseaidy, WM AU - Cleaveland, R AU - Baugh, JW T2 - SCIENCE OF COMPUTER PROGRAMMING AB - This paper presents the results of a case study involving the use of a formal graphical notation, Modechart, and an automatic verification tool, the Concurrency Workbench, in the analysis of the design of a fault-tolerant active structural control system. Such control systems must satisfy strict requirements on their timing behavior; we show how to use various equivalence-based features supported by the Workbench to examine the timing behavior of different design alternatives, one of which has in excess of 1019 states. The central insight arising from the study involves the importance of compositionality for reasoning about large and complex systems; in particular, the success of the case study depends integrally on our notation's and tool's support of componentwise minimization. DA - 1997/7// PY - 1997/7// DO - 10.1016/S0167-6423(96)00031-7 VL - 29 IS - 1-2 SP - 99-122 SN - 1872-7964 KW - active structural control systems KW - safety critical KW - component-wise state space reduction ER - TY - JOUR TI - Effects of random wave surface fluctuation on response of offshore structures AU - Yang, CH AU - Tung, CC T2 - PROBABILISTIC ENGINEERING MECHANICS AB - This paper seeks to determine the effects of free surface fluctuation on the response of an offshore structure in a random wave field. The structure is idealized as a massless uniform vertical column fixed at the sea bed carrying a concentrated mass at its top. The waves are linear, Gaussian, stationary and longcrested with narrow-band spectrum. The wave forces are computed using the Morison equation. It is shown that free surface fluctuation reduces structural response, more so in shallower than in deeper water, especially when the sea is high and when the structure is susceptible to dynamic action. DA - 1997/1// PY - 1997/1// DO - 10.1016/S0266-8920(96)00009-4 VL - 12 IS - 1 SP - 1-7 SN - 0266-8920 ER - TY - JOUR TI - Potential toxicity and aerobic biodegradability of sodium silicate chemical grout leachate AU - Malone, JM AU - StJohn, TW AU - Barlaz, MA AU - Borden, RH T2 - ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY AB - Large quantities of organic reagents are used in sodium silicate grouts for the stabilization of granular soils prior to construction projects. However, the fate and effects of these reagents in the subsurface are unknown. In this study, leachate from sodium silicate grouted soil specimens was tested for acute toxicity using Daphnia magna and Vibrio fisheri (Microtox®) assays. Additionally, a soil biometer test was used to measure the aerobic biodegradability of the grout leachate. Median lethal concentrations (LC50s) ranged from 1,220 to 3,260 mg/L as total organic carbon (TOC) for the D. magna test and from 4,500 to 22,180 mg/L as TOC for the Microtox test. More than 80% of the organics contained in the grout leachate were biologically converted to carbon dioxide in less than 30 d. The grout was found to be far less toxic than other common organic chemicals such as phenol. DA - 1997/3// PY - 1997/3// DO - 10.1897/1551-5028(1997)016<0442:PTAABO>2.3.CO;2 VL - 16 IS - 3 SP - 442-446 SN - 1552-8618 KW - Daphnia magna KW - Microtox(R) KW - sodium silicate KW - biodegradability KW - chemical grout ER - TY - JOUR TI - Intelligent traffic data processing for ATIS applications AU - Tarko, A. AU - Rouphail, N. T2 - Journal of Transportation Engineering AB - Real-time traffic data are the lifeline sustaining the operation of Advanced Traffic Management and Advanced Traveler Information Systems (ATMS/ATIS). Data are essential to drive algorithms related to congestion/incident detection, travel time forecasting, and real-time route guidance. A common problem in many ATMS/ATIS applications is the sparsity of real-time traffic data, reflecting the financial constraints of acquiring and maintaining large-scale traffic monitoring systems. This paper proposes the use of intelligent processing, or data integration tools, to overcome the data sparsity problem and make the best use of existing data resources. This approach recognizes the elements of uncertainty and vagueness in defining and solving the problem. An example application of the proposed data integration method is presented in the context of a congestion detection algorithm. The method uses an imprecise knowledge representation within the framework of fuzzy operator logic (FOL) and the modified Dempster-Shafer rule of combination. Results indicate that knowledge of a link congestion status (i.e., congested or uncongested) increased several folds after the data integration algorithm was applied. Further work is needed to calibrate the algorithm in the field (in this study simulation was used) and to apply the procedures on large-scale networks. DA - 1997/// PY - 1997/// DO - 10.1061/(ASCE)0733-947X(1997)123:4(298) VL - 123 IS - 4 SP - 298-307 ER - TY - CONF TI - Hurricane Fran damage observations AU - Norris, R. E. AU - Tayebali, A. A. C2 - 1997/// C3 - Eight U.S. National Conference on Wind Engineering, Baltimore, Maryland, June, 1997 DA - 1997/// M1 - 1997 June ER - TY - JOUR TI - Filtration of Fly Ash Using Nonwoven Geotextiles: Effect of Sample Preparation Technique and Testing Method AU - Akram, M. H. AU - Gabr, M. A. T2 - Geotechnical Testing Journal AB - Abstract The long-term filtration behavior of nonwoven geotextiles with fly ash is investigated using gradient ratio tests [ASTM Test Method for Measuring the Soil-Geotextile Clogging Potential by the Gradient Ratio (D 5101-90)] for the duration of approximately ≈4000 h under an applied hydraulic gradient of 3. In parallel, rigid wall permeability tests under the relatively high hydraulic gradient of 25 are conducted to investigate the potential of expediently simulating the long-term filtration behavior of the geotextile-fly ash system. Four nonwoven geotextiles ranging in apparent opening size from No. 70 to 170 are used with specimens prepared using a dry method and a slurry method of preparation and then back-saturated with deaired water. Results indicated that the fly ash-geotextile systems are stabilized after approximately 2000 h with less piping observed for the slurry specimens. Permeability across the slurry specimens is measured to be 1/2 to 1/3 that of the dry specimens. Testing under a hydraulic gradient of 25 and for the duration of 25 h has yielded a steady state k value similar to those obtained from the GR tests after a testing duration of 4000 h. All the geotextile-fly ash systems are categorized as stable based on the stability limit set for the granular filters with the measured rate of fly ash passing through the geotextiles found to be less than or equal to 0.04 g/cm2. DA - 1997/9// PY - 1997/9// DO - 10.1520/gtj19970001 VL - 20 IS - 3 SP - GTJ19970001 ER - TY - JOUR TI - Fatigue characterization of asphalt concrete using viscoelasticity and continuum damage theory AU - Kim, Y. R. AU - Lee, H. J. AU - Little, D. N. T2 - Journal of the Association of Asphalt Paving Technologists DA - 1997/// PY - 1997/// VL - 66 IS - 1997 SP - 520-569 ER - TY - JOUR TI - Development of an information model for composites design data AU - Spainhour, LK AU - Rasdorf, WJ T2 - ENGINEERING WITH COMPUTERS AB - Material properties data, particularly those of advanced composite materials such as fiber-reinforced plastics, provides a very complex domain which is difficult to computerize. As a foundational activity supporting the development of material property databases, we have examined and modeled the data contained within this large, diverse, and intricate domain. Our primary objective was to gain a better understanding of the data involved in this system and their transformation and use. We examined the life cycle of a fiber-reinforced composite material, from a raw material to a manufactured product, focusing on the various applications which require and/or supply materials data and the types of materials data which must be included. A high-level information model was created to illustrate the overall picture of composite materials data which emerged from this analysis. This model provides a global view of the data encompassed in the domain of composite materials, and forms the basis of a formal conceptual model from which databases may be developed. DA - 1997/// PY - 1997/// DO - 10.1007/BF01201860 VL - 13 IS - 1 SP - 48-64 SN - 0177-0667 KW - composite materials KW - conceptual modeling KW - database design KW - fiber-reinforced plastics KW - information modeling ER - TY - JOUR TI - Site-specific variability in BTEX biodegradation under denitrifying conditions AU - Kao, CM AU - Borden, RC T2 - GROUND WATER AB - Abstract Laboratory microcosm experiments were conducted to evaluate the feasibility of benzene, toluene, ethylbenzene, m‐xylene, and o‐xylene (BTEX) biodegradation under denitrifying conditions. Nine different sources of inocula, including contaminated and uncont animated soil cores from four different sites and activated sludge, were used to establish microcosms. BTEX was not degraded under denitrifying conditions in microcosms inoculated with aquifer material from Rocky Point and Traverse City. However, rapid depletion of glucose under denitrifying conditions was observed in microcosms containing Rocky Point aquifer material. TEX degradation was observed in microcosms containing Rocky Point aquifer material. TEX degradation was observed in microcosms containing aquifer material from Fort Bragg and Sleeping Bear Dunes and sewage sludge. Benzene was recalcitrant in all microcosms tested. The degradation of o‐xylene ceased after toluene, ethylbenzene, and m‐xylene were depleted in the Fort Bragg and sludge microcosms, but o‐xylene continued to degrade in microcosms with contaminated Sleeping Bear Dunes soil. The most probable number (MPN) of denitrifiers in these nine different inocula were measured using a microtiter technique. There was no correlation between the MPN of denitrifiers and the TEX degradation rate under denitrifying conditions. Experimental results indicate that the degradation sequence and TEX degradation rate under denitrifying conditions may differ among sites. Results also indicate that denitrification alone may not be a suitable bioremediation technology for gasoline‐contaminated aquifers because of the inability of denitrifiers to degrade benzene. DA - 1997/// PY - 1997/// DO - 10.1111/j.1745-6584.1997.tb00087.x VL - 35 IS - 2 SP - 305-311 SN - 1745-6584 ER - TY - JOUR TI - Optimal design of advanced power systems under uncertainty AU - Diwekar, UM AU - Rubin, ES AU - Frey, HC T2 - ENERGY CONVERSION AND MANAGEMENT AB - Technical and economic uncertainties are not rigorously treated or characterized in most preliminary cost and performance estimates of advanced power system designs. Nor do current design methods rigorously address the issues of design under uncertainty. However, process costs and other important quality measures, such as controllability, safety, and environmental compliance, largely depend on the process synthesis stage. This conceptual design stage involves identifying the basic flowsheet structures from a typically large number of alternatives. This paper describes recent developments in on-going research to develop and demonstrate advanced computer-based methods for dealing with uncertainties that are critical to the design of advanced coal-based power systems. Results are presented illustrating the use of these new modeling tools for the environmental control design of an advanced energy system based on an integrated gasification combined cycle (IGCC) for electric power generation. DA - 1997/// PY - 1997/// DO - 10.1016/S0196-8904(96)00184-7 VL - 38 IS - 15-17 SP - 1725-1735 SN - 0196-8904 KW - process optimization KW - process synthesis KW - uncertainty KW - energy systems KW - environmental control technology ER - TY - JOUR TI - Natural attenuation of MTBE and BTEX: How do you accurately predict downgradient transport? AU - Borden, R. C. T2 - Eos (Richmond, Va.) DA - 1997/// PY - 1997/// VL - 78 IS - 17 SP - S127 ER - TY - JOUR TI - Instability and movements of ocean floor sediments: a review AU - Rahman, M. S. T2 - International Journal of Offshore and Polar Engineering DA - 1997/// PY - 1997/// VL - 7 IS - 3 SP - 220-225 ER - TY - JOUR TI - Control of BTEX migration using a biologically enhanced permeable barrier AU - Borden, RC AU - Goin, RT AU - Kao, CM T2 - GROUND WATER MONITORING AND REMEDIATION AB - A permeable barrier system. consisting of a line of closely spaced wclls. was installed perpendicular to ground water flow to control the migration of a dissolved hydrocarhon plume. The wells were charged wiih concrete briquets that release oxygen and nitrate at a controlled rate. enhancing aerobic bio-degradation in the downgradient aquifer. Laboratory batch reactor experiments were conducted to identify concrete mixtures that slowly released oxygcn over an extended time period. Concretes prepared with urea hydrogen peroxide were unsatisfactory, while concretes prepared with calcium peroxide and a proprietary formalation of magnesium peroxide (ORC®) gradually released oxygen at a steadily declining rate. The 21 percent MgO2 conerete cylinders and briquets released oxygen at measurable rates for up to 300 days, while the 14 percent CaO2 briquets were exhausted by 100 days. A full-scale permeable barrier system using ORC was constructed at a gasoline-spill site. During the first 242 days of operation. total BTFX decreased from 17 to 3.4 mg/L. and dissolved oxygen increased from 0.4 to 1.8 mg/L. during transport through the barrier. Over time, BTEX treatment efficiencies declined. indicating the barrier system had becomc less effective in releasing oxygen and nutrients to the highly contaminated portion of the aquifer. Point dilution tests and sediment analyses performed at the conclusion of the project indicated that ihc aquifer in the vicinity of the remediation wells had been clogged by precipitation with iron minerals. This clogging is believed to result from high pH from the concrete and oxygen released by ihc ORC. Oxygen-releasing permeable barriers and other aerobic bioremediation processes should be used with caution in aquifers with high levels of dissolved iron. DA - 1997/// PY - 1997/// DO - 10.1111/j.1745-6592.1997.tb01186.x VL - 17 IS - 1 SP - 70-80 SN - 1745-6592 ER - TY - JOUR TI - Concrete crack repair by stitches AU - Hamoush, S AU - Ahmad, SH T2 - MATERIALS AND STRUCTURES DA - 1997/// PY - 1997/// DO - 10.1007/BF02498565 VL - 30 IS - 201 SP - 418-423 SN - 0025-5432 ER - TY - JOUR TI - A mathematical programming approach for generating alternatives in discrete structural optimization AU - Baugh, JW AU - Caldwell, SC AU - Brill, ED T2 - ENGINEERING OPTIMIZATION AB - Structural design, like other complex decision problems, involves many tradeoffs among competing criteria. While mathematical programming models are increasingly realistic, there are often relevant issues that cannot be easily captured, if at all, in a formal system. This paper describes an approach to modelling that recognizes these limitations and allows a designer to explore unmodelled issues in a joint human-computer cognitive system. A prototype based on this approach is presented for topological truss optimization, and three modelling techniques are contrasted for their effectiveness in producing “different” alternatives. The results show that alternatives produced using these techniques are good with respect to modelled objectives, and yet are different, and often better, with respect to interesting objectives not present in the model. DA - 1997/// PY - 1997/// DO - 10.1080/03052159708941125 VL - 28 IS - 1-2 SP - 1-31 SN - 0305-215X KW - multiple-objective programming KW - decision-support systems KW - mathematical modelling KW - design ER - TY - JOUR TI - Tensile behavior of slurry infiltrated mat concrete (SIMCON) AU - Krstulovic-Opara, N. AU - Malak, S. T2 - ACI Materials Journal DA - 1997/// PY - 1997/// VL - 94 IS - 1 SP - 39-46 ER - TY - JOUR TI - Flexural behavior of composite r.c.-Slurry Infiltrated Mat Concrete (SIMCON) members AU - Krstulovic-Opara, N. AU - Dogan, E. AU - Uang, C.-M. AU - Haghayeghi, A. R. T2 - ACI Structural Journal DA - 1997/// PY - 1997/// VL - 94 IS - 5 SP - 502-512 ER - TY - JOUR TI - Evaluating acids and chelating agents for removing heavy metals from contaminated soils AU - Neale, CN AU - Bricka, RM AU - Chao, AC T2 - ENVIRONMENTAL PROGRESS AB - Abstract The prevalence of heavy metal soil contamination at Army facilities poses a serious threat to human health and the environment. To address this problem, the US Army Engineer Waterways Experiment Station in Vicksburg MS is developing a mobile piot‐scale soil washing treatment facility that can be used to remove metals from the contaminated soils. To support this project, laboratory studies were conducted on both acids and chelating agents to evaluate their ability in extracting heavy metals from contaminated soils. Eight soils contaminated with lead, cadmium, and chromium were selected for use in this study. Contaminant concentrations in the various soils ranged from 4,000–30,000 mg/kg lead, 40–1,000 mg/kg cadmium, and 500–2,000 mg/kg chromium. The results indicated that, before a full‐scale clean‐up is initiated, a preliminary investigation is needed to determine principal contaminants of concern, their concentrations, and soil type followed by treatability studies to determine optimal reagent and concentrations of reagents for cleanup. Specific results from this study also indicated that Cd was the easiest metal to remove from soils followed by Pb and Cr. The results also suggested that the strong acids and chelating agents were both effective extracting agents, and the latter group of compounds may be more useful in soil washing because they are less harmful to the soil environment. Finally, higher initial concentrations of metal contaminants in the soil resulted in greater metal removal efficiencies using the reagents. DA - 1997/// PY - 1997/// DO - 10.1002/ep.3300160416 VL - 16 IS - 4 SP - 274-280 SN - 0278-4491 ER - TY - JOUR TI - Seismic response of tuned single degree of freedom secondary systems AU - Gupta, A AU - Gupta, AK T2 - NUCLEAR ENGINEERING AND DESIGN AB - Modal synthesis procedure for evaluating spectral acceleration in the single degree of freedom (SDOF) secondary system oscillator is studied. Problems encountered in the evaluation of response for secondary oscillators that are tuned or nearly tuned with the primary system modes are discussed and solutions to these problems are presented. A new hybrid approach is proposed that gives accurate spectral acceleration in tuned secondary systems for both cases of zero and non zero mass ratio in structures that are nonclassically damped. Formulations are developed to evaluate the interaction-free (zero mass ratio) instructure spectral accelerations for perfectly tuned secondary oscillators in a coupled primary-secondary system when the two uncoupled systems have same damping characteristics (classical damping case). DA - 1997/7// PY - 1997/7// DO - 10.1016/S0029-5493(96)00003-9 VL - 172 IS - 1-2 SP - 17-25 SN - 0029-5493 ER - TY - JOUR TI - Direct magnetic field measurement of flow dynamics in magnetized coaxial accelerator channels AU - Black, DC AU - Mayo, RM AU - Caress, RW T2 - PHYSICS OF PLASMAS AB - A miniature magnetic probe array, consisting of ten spatially separated coils, has been used to obtain profile information on the time-varying magnetic field within the 2.54 cm wide flow channel of the Coaxial Plasma Source experiment (CPS-1) [R. M. Mayo et al., Plasma Sources Sci. Technol. 4, 47 (1995)] at the North Carolina State University. Two-dimensional (2-D) current profiles within the annular flow channel, which were constructed from the time-varying magnetic field data, reveal several complex features reflecting the influence of gun inductance, the Hall effect, and the applied magnetic field. When an external, electrode linking magnetic field is applied, the evolution of the 2-D current profile shows evidence of an ionizing shock front identified by a narrow current sheet propagating through the channel during the first few microseconds of the discharge. The thickness of this current sheet is on the same order as both the collisional mean-free path and the ion electromagnetic skin depth. In this applied field case, the plasma is prevented from advancing ahead of the current sheet by the applied magnetic field, which turns the ions and electrons without collisions. In the absence of an applied field, plasma is able to advance ahead of the current sheet, where it may initiate ionization downstream before the advance of the ionization front. DA - 1997/8// PY - 1997/8// DO - 10.1063/1.872415 VL - 4 IS - 8 SP - 2820-2836 SN - 1089-7674 ER -