Scientific Results

This catalogue is obtained by conducting a systematic literature review of scientific studies and reviews related to monitoring, forecasting, and simulating the inland water cycle. The analysis maps scientific expertise across research groups and classifies findings by the type of inland water studied, application focus, and geographical scope. A gap analysis will identify missing research areas and assess their relevance to policymaking.

ID ā–² Type Year Authors Title Venue/Journal DOI Research type Water System Technical Focus Abstract Link with Projects Link with Tools Related policies ID
publications-4611 article 1988 Bhave, Pramod R. and Bhave, Pramod R. Calibrating Water Distribution Network Models Journal of Environmental Engineering 10.1061/(asce)0733-9372(1988)114:1(120) Calibration of water distribution network models is necessary in predicting their behavior under different loading conditions or in planning their expansions. Of the several data used in calibration, the predicted nodal demands and the pipe resistance coefficients are the least reliable. The model user usually adjusts the pipe resistance coefficients and/or the nodal demands by trialĪ²ā‚¬ĀandĪ²ā‚¬Āerror procedure and achieves calibration by making the predicted nodal pressures reasonably agree with the observed nodal pressures. A systematic iterative calibration procedure that decides the required adjustments in the nodal demands and pipe resistance coefficients is developed in this paper. The procedure is also illustrated through an example network.
publications-4612 article 2017 Knapp, G.L. and Knapp, G. L. and Mukherjee, T. and Mukherjee, T. and Mukherjee, Tridib and Zuback, J.S. and Zuback, J. S. and Wei, Huiliang and Wei, H. L. and Palmer, Todd and Palmer, Todd and De, A. and De, Amitava and DebRoy, T. and DebRoy, Tarasankar Building blocks for a digital twin of additive manufacturing Acta Materialia 10.1016/j.actamat.2017.06.039 Abstract Properties and serviceability of additively manufactured components are affected by their geometry, microstructure and defects. These important attributes are now optimized by trial and error because the essential process variables cannot currently be selected from scientific principles. A recourse is to build and rigorously validate a digital twin of the additive manufacturing process that can provide accurate predictions of the spatial and temporal variations of metallurgical parameters that affect the structure and properties of components. Key building blocks of a computationally efficient first-generation digital twin of laser-based directed energy deposition additive manufacturing utilize a transient, three-dimensional model that calculates temperature and velocity fields, cooling rates, solidification parameters and deposit geometry. The measured profiles of stainless steel 316L and Alloy 800H deposits as well as the secondary dendrite arm spacing (SDAS) and Vickers hardness measurements are used to validate the proposed digital twin. The predicted cooling rates, temperature gradients, solidification rates, SDAS and micro-hardness values are shown to be more accurate than those obtained from a commonly used heat conduction calculation. These metallurgical building blocks serve as a phenomenological framework for the development of a digital twin that will make the expanding knowledge base of additive manufacturing usable in a practical way for all scientists and engineers.
publications-4613 article 2000 Gargano, Rudy and Gargano, Rudy and Gargano, Rudy and Pianese, Domenico and Pianese, Domenico RELIABILITY AS TOOL FOR HYDRAULIC NETWORK PLANNING Journal of Hydraulic Engineering 10.1061/(asce)0733-9429(2000)126:5(354) This paper presents a methodology to evaluate the reliability of water distribution systems that can be used in the design phase and for identifying repair works to be carried out on existing systems. The methodology is based on the statistical analysis of dimensionless performance indices (\Ihydraulic performance indices\N) derived from a large number of simulations of various water system demand scenarios and/or operating conditions. The \Ihydraulic reliability index\N is assumed as the probability that, under a given operating condition, the hydraulic performance index will be above a certain threshold. Finally, the systemĪ²ā‚¬ā„¢s overall reliability (mechanical + hydraulic) is estimated using the \Ioverall reliability index\N, which is defined by the weighted mean of the hydraulic performance indices obtained for the various operating conditions. A case study using this methodology shows the concrete possibilities of applying this approach to a wide spectrum of cases, and the small influence on overall system reliability normally exerted by such events as the failure of links, pipes, and valves.
publications-4614 article 2013 Reifsnider, Kenneth and Reifsnider, Kenneth and Reifsnider, Kenneth and Majumdar, Parthasarathi and Majumdar, Prasun Multiphysics Stimulated Simulation Digital Twin Methods for Fleet Management 10.2514/6.2013-1578 The objectives of fleet management are typically readiness, availability, and reduced risk and cost. Of course, data management is essential to handle multiple data streams from many platforms. But the heart of successful, proactive fleet management is the science and engineering behind the interpretive analysis used for each "tail number." That is the focus of the present paper. Science and engineering have generally focused on detecting discrete events, especially early in life, then on deciding when a certain "collection" of those events warrants corrective action (e.g., maintenance). This approach has two serious shortcomings for composite material components. First, composite structures rarely fail from damage initiation; they generally fail from damage accumulation and interaction. Second, the limits on performance (e.g., stiffness, strength, and life) are determined by emergent behavior defined by interactive degradation events (from "the bottom") and by the assembly of extrinsic factors including manufacturing, geometry and morphology, load history, and expected performance (from the top). The present paper discusses a rational engineering approach to real-time "tail number" prognosis of composite structures based on the measurement and science-based interpretation of changes in multi-physical material properties. Examples of the approach will be provided and application paths discussed. Relationships to durability, reliability, risk, and liability will also be identified.
publications-4615 article 1980 Carver, Philip H. and Carver, Philip H. and Boland, John J. and Boland, John J. ShortĪ²ā‚¬Ā and longĪ²ā‚¬Ārun effects of price on municipal water use Water Resources Research 10.1029/wr016i004p00609 Empirical studies of the response of municipal water use to price have frequently failed to distinguish between long- and short-run aspects of adjustments in water use. Pooled time series and cross-sectional data for the Washington, D. C., metropolitan area are used to estimate both the long- and short-run response of aggregate water use to price. The data are fitted to a flow adjustment model of the Nerlove (1958) type. Short-run elasticity for aggregate annual water use is shown to be less than 0.1 in absolute value, while long-run elasticities are evidently within the range of results reported by previous investigators. When water use is separated into seasonal and nonseasonal components, however, the elasticities estimated for the seasonal component are substantially smaller (more inelastic) than previously reported, both in the short run and in the long run.
publications-4616 article 1982 Hanke, Steve H. and Hanke, Steve H. and de MarĪ“Ā©, L. and de Mare, Lennart RESIDENTIAL WATER DEMAND: A POOLED, TIME SERIES, CROSS SECTION STUDY OF MALMĪ“ā€“, SWEDEN1 Journal of The American Water Resources Association 10.1111/j.1752-1688.1982.tb00044.x : Shortcoming associated with past water demand studies are evaluated. To overcome these shortcomings, pooled, time series, cross section data from -6, Sweden, are used in an ordinary Least squares analysis to estimate the demand for residential water. Elasticities for five variables, including price and income, are estimated. An approach for the conduct of future water demand studies is suggested.
publications-4617 article 1989 Lansey, Kevin and Lansey, Kevin E and Duan, Ning and Duan, Ning and Mays, Larry W. and Mays, Larry W. and Tung, Yeou Koung and Tung, Yeou-Koung Water Distribution System Design Under Uncertainties Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(1989)115:5(630) A chance constrained model is presented for the minimum cost design of water distribution networks. This methodology attempts to account for the uncertainties in required demands, required pressure heads, and pipe roughness coefficients. The optimization problem is formulated as a nonlinear programming model which is solved using a generalized reduced gradient method. Details of the mathematical model formulation are presented along with example applications. Results illustrate that uncertainties in future demands, pressure head requirements, and pipe roughness can have significant effects on the optimal network design and cost.
publications-4618 article 1976 Morgan, W. Douglas and Morgan, W. Douglas and Smolen, Jonathan C. and Smolen, Jonathan C. CLIMATIC INDICATORS IN THE ESTLMATION OF MUNICIPAL WATER DEMAND Journal of The American Water Resources Association 10.1111/j.1752-1688.1976.tb02714.x JAWRA Journal of the American Water Resources AssociationVolume 12, Issue 3 p. 511-518 CLIMATIC INDICATORS IN THE ESTLMATION OF MUNICIPAL WATER DEMAND1 W. Douglas Morgan, W. Douglas Morgan Graduate Student in Geography and Urban Economics, University of California, Santa Barbara, California.Search for more papers by this authorJonathan C. Smolen, Jonathan C. Smolen Respectively, Associate Professor of Economics, University of California, Santa Barbara, California.Search for more papers by this author W. Douglas Morgan, W. Douglas Morgan Graduate Student in Geography and Urban Economics, University of California, Santa Barbara, California.Search for more papers by this authorJonathan C. Smolen, Jonathan C. Smolen Respectively, Associate Professor of Economics, University of California, Santa Barbara, California.Search for more papers by this author First published: June 1976 https://doi.org/10.1111/j.1752-1688.1976.tb02714.xCitations: 27 1 Paper No. 76028 of the Water Resources Bulletin. Discussions are open until February 1, 1977. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume12, Issue3June 1976Pages 511-518 RelatedInformation
publications-4619 article 1988 Nieswiadomy, Michael and Nieswiadomy, Michael and Molina, David J. and Molina, David J. Urban Water Demand Estimates Under Increasing Block Rates Growth and Change 10.1111/j.1468-2257.1988.tb00458.x A residential water demand equation is estimated using the only data set on water consumption that contains time series (monthly) observations on individual customers facing an increasing block rate schedule. Because the price of water both determines, and is determined by, usage, ordinary least squares estimation will yield biased estimates. Thus, two-stage least squares and instrumental variables techniques are used. The estimated coefficients on lawn size, weather, house size, and income have the expected signs and are statistically significant. However, there is not any significant response to changes in water price, perhaps due to the relatively low cost of water.
publications-4620 article 1980 Rahal, Cm and Rahal, Cm and Sterling, Mjh and Sterling, Mjh and Coulbeck, B. and Coulbeck, B. and Newton and Newton and Raphson and Raphson and Fortran and Fortran PARAMETER TUNING FOR SIMULATION MODELS OF WATER DISTRIBUTION NETWORKS. 10.1680/iicep.1980.2375 Keywords SHEFFIELD UNIVERSITY, DURHAM UNIVERSITY, LEICESTER POLYTECHNIC PARAMETERS, TUNING, SIMULATION, MODELS, WATER, DISTRIBUTION, NETWORKS, METHODS, DATA, MEASUREMENT, CALIBRATION, REPRESENTATION, SCHEMATIC, TECHNIQUES, EQUATIONS, SELECTION, ITERATIVE, ALGORITHMS, IMPLEMENTATION, PROGRAMS, COMPUTERS, PUMPS, PUMPING STATIONS, PIPES, RESISTANCE... Show All