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Comparison of RANS and Potential Flow Force Computations for the ONR Tumblehome Hullfrom in Vertical Plane Radiation and Diffraction ProblemsField, Parker Lawrence 01 June 2013 (has links)
The commercial CFD software STAR-CCM+ is applied as a RANS solver for comparison with potential flow methods in the calculation of vertical plane radiation and diffraction problems. A two-dimensional rectangular cylinder oscillating in an unbounded fluid is first considered, and the added mass result shown to agree well with the analytical potential flow solution. Hydrodynamic coefficients are then determined for the cylinder oscillating in heave and sway about a calm free surface. Predicted values are observed to coincide with available experimental and linear potential flow results for most amplitudes and frequencies of oscillation examined. A three-dimensional radiation problem is then studied in which 1-DoF heave and pitch motions are prescribed to the ONR Tumblehome hullform in calm water at zero forward speed and Fn 0.3. Combinations of amplitude and frequency of oscillation ranging from small to large are considered. Results are compared with several potential flow codes which utilize varying degrees of linearization. Differences in the force and moment results are attributed to particular code characteristics, and overall good agreement is demonstrated between RANS and potential flow codes which employ a nonlinear formulation. The ONR Tumblehome is next held static in incident head waves of small and large steepness and zero forward speed or Fn 0.3. Force and moment time histories of the periodic response are compared with the same set of potential flow codes used in the radiation problem. Agreement between potential flow and RANS is reasonable in the small wave steepness case. For large wave steepness, the nonlinear wave response is seen to be important and the RANS solution does not generally agree well with potential flow results. / Master of Science
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Design, Test, and Calibration of the Utah State University Floating Potential ProbeGregory, Jessica D. 01 December 2009 (has links)
The ionosphere is a conducting layer in the Earth's upper atmosphere and is the nearest naturally occurring plasma environment. Inherent to all plasma environments is an electric field. Currently, the double electric field probe is the most successful instrument for measuring the electric fields of space plasmas. Utah State University/Space Dynamics Lab has developed a double electric field probe, called the Floating Potential Probe (FPP), with a slightly different instrumentation approach than what has been done previously. The FPP is one component of a suite of instruments that launched in fall of 2007 from Wallops Island, Virginia, as part of NASA's sounding rocket program to an approximate altitude of 450km. This mission is nicknamed "The Storms Mission.'' In general, an electric field probe acts as a voltmeter to measure the electric potential between a probe located near the end of a long boom and the skin of the rocket. This measurement is also called the floating potential. To obtain electric field measurements, the floating potential is gathered from two probes located 180 degrees apart and differenced to calculate the electric potential between probes and thereby the ambient electric field. Historically, this has been accomplished with an entirely analog circuit implementation. For the Storm Mission, the signals are digitized before the differencing occurs. Then during data analysis, the signals can either be differenced digitally to produce the ambient electric field or summed to observe the floating potential of the payload skin. Additionally, the signals are digitized to 20 bits giving a far greater dynamic range than is typically achieved in similar direct current (DC) coupled instruments. This thesis discusses the theory, design, test, and calibration efforts of the FPP for the Storms Mission.
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The interactive potential of polyethylene oxide as a tool to adjust drug deliveryIsmail, Fatima 07 April 2011 (has links)
MS, Pharmaceutical Affairs, Faculty of Health Sciences, University of the Witwatersrand / PEO (Polyethylene Oxide) is one of the most important biodegradable polymers used in pharmaceutical formulations, mainly because of its non-toxicity, high water-solubility and swellability, insensitivity to the pH of the biological medium and flexibility during dosage form production (Kim, 1995; Picker-Freyer, 2006; Kiss et al., 2008).
The lack of studies attempting to achieve controlled drug delivery of hydrophilic drugs has provided us with motivation to use a drug of this nature but we have combined it with a PEO-electrolyte combination in order to control drug delivery. This study was aimed at modifying the physicochemical and physicomechanical properties of PEO in order to influence the hydrodynamic diffusion of its three-dimensional network. Hence, through such alteration, it was envisaged that if drug is loaded into its PEO matrix, its solubility and dissolution can be regulated in order to achieve zero-order influx of dissolution medium. The interaction between PEO and electrolytes may allow for precipitation of ions on the polymer backbone. This would lead to the attraction of water molecules to the ions. As a result, this would cause dehydration of the polymer matrix, hence minimising its mobility and relaxation.
In this study, 36 PEO-electrolyte combinations were prepared by combining a high molecular weight PEO with different statistically planned combinations of electrolytes. The 36 formulations were microscopically analyzed and subjected to textural analysis. The salted-out PEO-electrolyte combinations were then further selected and analyzed. Assessment of the molecular structural transition and thermal compatibility analysis indicated minimal interaction between the electrolytes and PEO indicating that the polymer-electrolyte combination was stable enough to be employed as a medium for controlled drug release. The polymer-electrolyte combination was combined with a model drug, diphenhydramine HCl to form a tablet matrix and then subjected to dissolution. In vitro drug release varied depending on the different electrolytes and their combinations. The type of polymer, molecular weight of the polymer, concentration of the polymer, different electrolyte combinations and solubility of the drug played a significant role in controlling drug release.
After optimization of the fracture force, resilience and work performed values, results have established that equal concentrations of Na2CO3 and K2HPO4 are desirable for achieving controlled release of drug from the salted-out PEO combination in a zero-order manner. Furthermore, Na2CO3 and K2HPO4 had a significant influence on controlling the release of drug from the salted-out PEO combination due to crosslinking between PEO and the electrolytes ultimately leading to zero-order release kinetics. The salting-out of PEO notably modified the physicochemical and micromechanical properties of basic PEO, which demonstrably enhanced the ability of the sample to achieve controlled drug release. The formulation strategy employed in this study where in our sample drug, diphenhydramine HCl was combined with a PEO-electrolyte combination has shown promising results in regulating drug release.
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An evoked potential study of the cross-race effect of facial recognition in the South African context.Greenslade, Daniel John 05 July 2012 (has links)
This research aimed to explore and contextualise research on the electrophysiological potentials evoked in response to human face recognition within the South African context. Previous research provides evidence that there is a measurable difference in the electrophysiological response to faces of people of other racial groups when compared to the response to one’s own race group. The difference is seen in greater peak amplitudes in response to one’s own-race (indicating greater attention being granted) in comparison to the other-race. This has been labelled the Cross-Race Effect. This research also attempted to expand on previous research in the use of a mixed-race sample and realistic colour images, in contrast to previously used greyscale images. A purposive sample of 40 students at the University of the Witwatersrand was split equally between gender and race (Black and White) with an Indian control group. The electrical potentials elicited by the facial stimuli were extracted from the ongoing electroencephalograms. The results obtained displayed inverse results to those found internationally, with Black participants eliciting no differences between racial groups, and White participants eliciting a greater peak amplitude to Black (other-race) faces. A gender effect was also seen, with White participants eliciting greater peak amplitudes towards female faces, while Black participant again showed no differences between male and female faces. Trends displayed in the results, and the significance thereof, are discussed, and the importance of the effect of society of developmental neurology is highlighted, with the rephrasing of cultural neuroscience to Socio-Cultural Neuroscience. The results ultimately suggest that the internationally seen cross-race effect is absent in a young South African population (with the principle of increased exposure leading to increased attention still in effect), indicating that South Africa is beginning to move away from racial discrimination, and moving towards a future of true integration and equality.
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Generation of Potential Narratives in Interactive FictionScigajlo, Adrian January 2023 (has links)
Digital media has created more opportunities for stories to be interactive, allowing the user to participate in plot events and even change the direction of a story. Interactivity can make stories more engaging however if the plot can change as a result of user input then the story becomes non-linear. The resulting system is known as a potential narrative because a narrative is only presented through user interaction. Non-linear stories require extra considerations and content compared to a linear story of similar length. Computer generated content for video games has grown as a field and this raises the possibility of using computer assistance for the creation and management of interactive stories. This thesis explores the paradigm required for both computers and developers to understand potential narratives. The success of a potential narrative requires the same coherency and credibility that a regular story does, in addition to a new layer known as player agency. Coherency refers to the logical causal progression of a plot, credibility is the verisimilitude of the presented story world and player agency is how satisfying the interactive elements are. These three criteria are the guiding principles for the creation of an intuitive potential narrative model. We present a state transition model for potential narratives as well as a prototype using relational programming to generate coherent traversals through a manually authored potential narrative. / Thesis / Master of Applied Science (MASc) / Writing stories for video games and interactive fiction is a time consuming and complex affair. The resulting web of possible events and pathways through the non-linear story is known as a potential narrative. Computer assisted tools for creating potential narratives could cut down on production costs and open the door for stories that are able to adapt to the player in real-time. In order for these generated stories to be viable they must be coherent, credible and allow for player agency. These criteria describe whether stories make logical sense and are satisfying for the user to interact with. Taking that into account we present a model for coherent interactive stories which keeps track of the story world and the events that could happen within it. As a proof of concept we implement this model with a prototype to generate traversals through a manually authored potential narrative.
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Response of Oxidation-Reduction Potential to Changes in Hydrology and Vegetation in an Agricultural Drainage Ditch with WeirsShoemaker, Cory 17 August 2013 (has links)
Excess nutrients entering aquatic systems cause negative effects downstream. Oxidation-reduction potential (Eh) is an inexpensive proxy which can be used to define the potential nutrient reducing capacity of a system, in particular denitrification. My thesis attempts to determine effects of hydrology and vegetation manipulations on Eh in an agricultural drainage ditch with weirs using continuous automated data loggers to monitor the system. Accuracy and precision of the continuous automated data loggers was confirmed through laboratory and field testing. Effects of hydrology and vegetation on Eh were quantified during testing from May-September 2012 in east-central Mississippi. Vegetation affected Eh (t=-1.75, P=0.08, df=9,754) whereas changes in hydrology also affected Eh (t=7.05, P<0.001, df=9,754). Modeling of these variables indicated the interaction of hydrology and vegetation was the most influential factor measured. Through management of hydrology and vegetation in ditches, Eh can be managed to create conditions conducive for denitrification.
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40%-regeln : Konsten att utmana sig själv kreativt / 40%-rule : The art of challenging yourself creativlyJohansson, Martin January 2023 (has links)
Jag har en längre tid känt mig både ineffektiv och osäker när det kommer till låtskrivning och producering av musik. En stor inspirationskälla för mig har länge varit ultralöparen David Goggins, som hjälpt mig mycket gällande personlig utveckling i livet. Jag ville därför testa att applicera Goggins lärdomar i mitt musikskapande för att försöka hitta ett effektivt arbetssätt och ökat självförtroende inom området. Jag har skrivit, producerat, mixat och publicerat totalt 15 låtar som jag skapade under en period av fem veckor. Kravet för varje produktion var att åstadkomma minst en välljudande demo. Jag har lärt mig hur viktigt det är att utmana sig själv för att utvecklas, samt vikten av att hålla sig fokuserad och strukturerad under pressade situationer. Jag lyckades effektivisera mitt arbetssätt en hel del då jag lärde mig saker under tiden som blev användbara när pressen var som högst, det blev dock på bekostnad av noggrannhet.
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An architecture of authority: the jail/sheriff's residences of northwest Ohio, 1867-1902Bosworth, Frank Malin 02 October 2007 (has links)
This study investigates the historic development, classification, and reuse potential of the jail/ sheriff's residence building-type. Using collected data, the study examines fifteen buildings in northwest Ohio and develops a classification system for the building type. The historic precedents for the building type were investigated and traced to their English roots, namely I the county gaol that emerged from the Bridewell in the eighteenth century. The Jail/Sheriff's Residence is a heretofore unclassified building-type consisting of two primary parts, a residence for the County Sheriff and the county jail. The buildings are primarily located in Ohio and nearby States. / Ph. D.
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Stratigraphic Analysis and Reservoir Characterization of the Late Oligocene-Early Miocene, Upper Yenimuhacir Group, Thrace Basin, TurkeyDiyarbakirli, Ali Can 09 December 2016 (has links)
The Thrace Basin, NW Turkey, is one of the most important basins in Turkey in terms of hydrocarbon potential. Previous studies, starting in the 1930s, focused on tectonics, basin evolution, sedimentation and stratigraphy, depositional systems, and hydrocarbon potential. Eocene turbiditic sandstones and reefal limestones, and Oligocene deltaic sandstones are the major reservoir targets in the basin today. The focus of this research is the Upper Oligocene deltaic sandstones, namely the Danismen and Osmancik formations, which contain potential hydrocarbon reservoirs. The aims of research were to develop a better understanding of the geometric configuration of the Oligocene strata and to identify potential reservoirs within the study area. Accordingly, the geometric configurations of the strata were delineated using 3D seismic reflection data whereas petro-physical properties of the target formations were determined using wireline logs from three wells. A right-lateral strike slip or reverse fault system and associated NW-SE trending asymmetric fold extend across the study area. Both the fault system and the fold are truncated beneath the Miocene unconformity and are thus dated as late Oligocene to early Miocene in age. The Miocene unconformity forms a stratigraphic trap whereas the fault system and associated fold construct a NW-SE trending structural trap. Hydrocarbon-bearing, five main clean sandstone (shale volume less than %10) intervals were identified using wireline logs and evaluated as potential targets. Hydrocarbon concentrations increase through the fold structure. Thus, the fault system and the associated asymmetric fold were the main factors that affected the zonal distribution of hydrocarbons in the study area. / Master of Science
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Nuclear Potential and Nuclear MatterKiang, David Bun I 03 1900 (has links)
The one-boson-exchange potential model is studied in some detail. The parameters of a velocity-dependent potential based on such a model are fitted to reproduce two-body
scattering data. This potential is then used in nuclear matter calculations by means of the reference spectrum method. It is shown that the average binding energy of a nucleon in
nuclear matter and the saturation density are in reasonable agreement with the experimental values. / Thesis / Doctor of Philosophy (PhD)
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