Browsing by Subject "methodology"
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Item A Statistical Methodology for Prediction Salinity in Upper Lavaca Bay(University of Texas at Austin, 1982-06) Hisao Yamada, S.; Armstrong, N.E.Item Complex Functional Surface Design for Additive Manufacturing(University of Texas at Austin, 2016) Morris, S.J.; Dudman, J.P.R.; Körner, L.; Melo, P.; Newton, L.H.; Clare, A.T.This paper presents a new methodology for the creation of advanced surfaces which can be produced by Additive Manufacturing (AM) methods. Since there is no cost for enhanced complexity, AM allows for new capabilities in surface design. Micro-scale surface features with varying size, shape and pitch can be manufactured by Two-Photon Polymerisation (2PP). Computer-Aided Design (CAD) tools allowing for this variation to be incorporated into the surface design are only just emerging. With the presented methodology, surfaces are created from a single feature design. Variation is applied to the surface features through algorithmic design tools, allowing for arrays of hundreds of unique features can be created by non-CAD experts. The translation of these algorithmic expressions from CAD to a physical surface is investigated. Using the proposed methodology, 2PP is used to create quasi stochastic surfaces for the purpose of enhancing the biointegration of medical implants against current state-of-the-art.Item Criteria and Methodology for Estiamting Municipal and Industrial S/W Ratios and Wastewater Quality Profiles(University of Texas at Austin, 1972-02) Malina, J.F.; Burleson, N.K.Item Full Waveform Inversion for Seismic Velocity and Anelastic Losses in Heterogeneous Structures(2007-12) Askan, Aysegul; Akcelik, Volkan; Bielak, Jacobo; Ghattas, Omar; Ghattas, OmarWe present a least-squares optimization method for solving the nonlinear full waveform inverse problem of determining the crustal velocity and intrinsic attenuation properties of sedimentary valleys in earthquake-prone regions. Given a known earthquake source and a set of seismograms generated by the source, the inverse problem is to reconstruct the anelastic properties of a heterogeneous medium with possibly discontinuous wave velocities. The inverse problem is formulated as a constrained optimization problem, where the constraints are the partial and ordinary differential equations governing the anelastic wave propagation from the source to the receivers in the time domain. This leads to a variational formulation in terms of the material model plus the state variables and their adjoints. We employ a wave propagation model in which the intrinsic energy-dissipating nature of the soil medium is modeled by a set of standard linear solids. The least-squares optimization approach to inverse wave propagation presents the well-known difficulties of ill posedness and multiple minima. To overcome ill posedness, we include a total variation regularization functional in the objective function, which annihilates highly oscillatory material property components while preserving discontinuities in the medium. To treat multiple minima, we use a multilevel algorithm that solves a sequence of subproblems on increasingly finer grids with increasingly higher frequency source components to remain within the basin of attraction of the global minimum. We illustrate the methodology with high-resolution inversions for two-dimensional sedimentary models of the San Fernando Valley, under SH-wave excitation. We perform inversions for both the seismic velocity and the intrinsic attenuation using synthetic waveforms at the observer locations as pseudoobserved data.Item Jewish Service Learning: An Analysis of Participant Jewish Identity and Program Characterisitcs(RGK Center, 2008-10) Rehnborg, Sarah; Lee, Jinwoo; Veron, Rachel; Zaligson, Jennifer AbzugItem Low Cost Numerical Modeling of Material Jetting-Based Additive Manufacturing(University of Texas at Austin, 2018) Hume, Chad A.; Rosen, David W.Material jetting-based additive manufacturing is a promising manufacturing approach with increasing interest in mesoscale applications such as microfluidics, membranes, and microelectronics. At these size scales, significant edge deformation is observed limiting the resolvable feature size. Currently, predicting and controlling such deformations would require extensive experimentation or computationally prohibitive simulations. The objective of this work is to develop a computationally low cost material jetting model that enables the simulation and prediction of mesoscale feature fabrication. To this end, a quasi-static boundary-based method is proposed and demonstrated as a simplified and accurate means of predicting the line-by-line, layer-by-layer feature development. The method is validated through comparison with the known analytical solution for a single droplet; then the method’s application to AM is demonstrated through modeling of representative mesoscale features. The benefits and limitations of each are discussed.Item Method for a Software-Based Design Check of Additively Manufactured Components(University of Texas at Austin, 2018) Tominski, J.; Lammers, S.; Wulf, C.; Zimmer, D.Additive manufacturing offers the potential to produce complex structures such as topology-optimized components or lattice structures. However, even these numerically generated structures are subject to manufacturing restrictions. Therefore, compliance with design rules has to be checked to ensure a robust production. For complex structures, this check requires a great effort. Hence, a method for a software-based design check that automatically verifies the compliance with design rules of complex structures has to be developed. Within the framework of the developed method, the frequently used STL format which is usually applied during preparation of the manufacturing process, is used. This format approximates components using triangles. By systematically linking these triangles, geometrical attributes of components which are relevant for a controlled manufacturing can be identified. Comparing these attributes to a database containing attribute limits of divergent manufacturing conditions allows a design check regarding robust manufacturing processes.Item Methodical Design of a 3D-Printable Orthosis for the Left Hand to Support Double Bass Perceptional Training(University of Texas at Austin, 2019) Borstell, D.; Walker, N.; Kurz, S.The evolution of Additive Manufacturing (AM) in the past decades has opened up its use to a wide range of new applications where conventional manufacturing methods dominated. Orthoses are medical devices, mostly used on legs or arms after injuries or surgery. Amongst other functions, they limit the possible movement of limbs or joints to prevent excessive movements or loads during remobilization. Their manufacturing process is predominantly manual and conventional using e.g. plaster casts and materials like foam, wood and textiles. Playing the acoustic double bass requires precise positioning of the left hand fingers on the fingerboard. Perception of the finger spacing is very important for good intonation. Different educational approaches have therefore been made to kinesthetic and perceptional training. Miniaturization and low forces allow applying additive manufacturing technology to a previously conventional device leading to a new approach to design a perceptional training device for the left hand: an individually shaped orthosis, which is lightweight, low cost, and adjustable and which can be worn during instrument practice.Item Methodology for Analyzing Effects of Urbanization on Water Resource Systems(University of Texas at Austin, 1978-01) Mays, L.W.; Tung, Y.K.Item Methodology for Determination of Texas Oil Fields Eligible for Variance from Area of Review Requirements in Underground Injection Control Regulations for Class II Injection Wells- Revised Final Technical Report(1998) Smyth, Rebecca C.; Nava, Robin C.; Sullivan, E. J.The permitting process for salt-water injection wells mandates that oil companies or operators conduct an Area of Review (AOR) study within a 0.25-mile radius of a proposed well. The primary goal of an AOR study is to pinpoint unplugged wells that could potentially allow injected fluids to migrate upward from the production zone, posing a risk to the overlying underground sources of drinking water (USDW). In collaboration with the Railroad Commission of Texas (RRC), the Bureau of Economic Geology (BEG) at the University of Texas at Austin assessed oil fields across Texas to explore potential variations to the AOR permitting process. This assessment focused on evaluating the separation between production-zone fluid levels and the base of USDW. The aim was to provide the RRC and the industry with valuable data and methodology to facilitate AOR variance applications and the review of oil fields in Texas. Upon querying the RRC's H15 database, 1,587 oil fields were identified with an average static fluid level at least 500 feet below the deepest USDW. Further querying by BEG revealed 113 oil fields with sufficient data for AOR variance analysis.Item Methodology to evaluate alternative coastal zone management policies: Application in the Texas Coastal Zone. Final Report: Volume I--Methodology(University of Texas at Austin, 1978) Gus Fruh, E.; Kier, R.S.Item Naphthalimide Trifluoroacetyl Acetonate: A Hydrazine-Selective Chemodosimetric Sensor(2013-08) Lee, Min Hee; Yoon, Byungkwon; Kim, Jong Seung; Sessler, Jonathan L.; Lee, Min Hee; Sessler, Jonathan L.The trifluoroacetyl acetonate naphthalimide derivative 1 has been synthesized in good yield. In acetonitrile solution, compound 1 reacts selectively with hydrazine (NH2NH2) to give a five-membered ring. This leads to OFF-ON fluorescence with a maximum intensity at 501 nm as well as easily discernible color changes. Based on a readily discernible and reproducible 3.9% change in overall fluorescence intensity, the limit of detection for 1 is 3.2 ppb (0.1 mu M), which is below the accepted limit for hydrazine set by the U.S. Environmental Protection Agency (EPA). Compound 1 is selective for hydrazine over other amines, including NH4OH, NH2OH, ethylenediamine, methylamine, n-butylamine, piperazine, dimethylamine, triethylamine, pyridine, and is not perturbed by environmentally abundant metal ions. When supported on glass-backed silica gel TLC plates, compound 1 acts as a fluorimetric and colorimetric probe for hydrazine vapor at a partial pressure of 9.0 mm Hg, with selectivity over other potentially interfering volatile analytes, including ammonia, methylamine, n-butylamine, formaldehyde, acetaldehyde, H2O2, HCl, and CO2 being observed. Probe 1 can also be used for the detection of hydrazine in HeLa cells and does so without appreciable interference from other biologically abundant amines and metal ions.Item New Methodologies for the Reliability-Based Analysis and Design of Water Distribution Systems(University of Texas at Austin, 1989-07) Mays, L.W.; Bao, Y.; Brion, L.; Cullinane, M.J. Jr.; Duan, N.; Lansey, K.; Su, Y.C.; Woodburn, J.Item New Methodologies for the Reliability-Based Analysis and Design of Water Distribution Systems(University of Texas at Austin, 1989-07) Mays, L.W.; Bao, Y.; Brion, L.; Cullinane, M.J. Jr.; Duan, N.; Lansey, K.; Su, Y.C.; Woodburn, J.Item Preserving & Improving Water Quality(Texas Commission on Environmental Quality, 2010) Texas Commission on Environmental QualityItem Review of AM Simulation Validation Techniques(University of Texas at Austin, 2017) Flood, Aaron; Liou, FrankDue to the complexity of Additive Manufacturing (AM), it can require many trial runs to obtain processing parameters which produce a quality build. Because of this trial and error process, the drive for simulations of AM has grown significantly. Simulations only become useful to researchers if it can be shown that they are true representations of the physical process being simulated. All simulations have different methods of validation to show that they are an accurate representations of the process. This paper explores the various methodologies for validation of laser based metal AM simulations, focusing mainly on the modeling of the thermal processes and other characteristics derived from thermal history. It will identify and explain the various validation techniques, specifically looking at the frequency of reported use of each technique.Item Special Report III: A Methodology for Investigating Fresh Water Inflow Requirements of a Texas Estuary Vol I. Methodology(University of Texas at Austin, 0000-00-00) Lambert, W.P.; Fruh, E.G.Item Special Report III: A Methodology for Investigating Fresh Water Inflow Requirements of a Texas Estuary Vol II. Appendices(University of Texas at Austin, 0000-00-00) Lambert, W.P.; Fruh, E.G.Item Texas Department of Water Resources Report LP-106: Final Report(University of Texas at Austin, 0000-00-00) Author unknown