cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Downhole Gas Separator Performance in Sucker Rod Pumping System
Creators: name: Guzman, Manuel
Publisher: name: The University of Texas at Austin
Year: 2005
Subjects: Gas separator
Artificial lift

description: Volumetric efficiency of a sucker rod pump has been a major concern for artificial lift designers for a long time. One way to reduce the amount of gas entering into the pump is to use downhole gas separators. The main purpose of these devices is to facilitate agglomeration of gas bubbles so that they migrate upwards and can be released through the casing annulus. Design and selection of downhole gas separators is usually done using heuristics. The objective of this research is to offer the oil industry novel software for the design and selection of gravity type downhole gas separators to improve the pump performance. Separator performance relations are based on laboratory data of 10 different gas separators for continuous flow (such as developed by the progressing cavity pumps). This data was used to generate correlations between the gas flowing through the separator, thesuperficial gas velocity in the annulus and the superficial liquid velocity inside theseparator. These relations were then applied to model the performance of the separator when operating in conjunction with a sucker rod pump. This model used actual plunger velocity data from different types of surface units to calculate the liquid fraction inside the pump for each combination of separator design and annular gas velocity. In addition, we developed a motorized butterfly valve to reproduce the intermittent flow observed in sucker rod pumps. Experimental results show that the downhole gas separation efficiency depends on the port area and the annular area inside the separator. When ports area is smaller than the annular area, the first controls the flow regime inside the separator. Results confirm that the downhole gas separator efficiency depends on the ratio between the plunger diameter and the downhole gas separator annular area. Additionally, visual observation confirms that the best way to maximize the gas separation is to set the intake below the perforations, if possible.
Antioxidant capacity and phenolic composition of leaves from 10 Bene (Pistacia atlantica subsp. kurdica) genotypes
Creators: name: Darvishzadeh, Reza
name: Hatamnia, Ali Asghar
name: Rostamzad, Arman
name: Mohammadyar Hosseini
name: Abbaspour, Nasser
name: Malekzadeh, Parviz
name: Bakhtyar Mohammad Aminzadeh
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Biological Sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Microbiology
subject: Biochemistry

description: Leaves of 10 Bene genotypes were collected from six provinces (West Azerbaijan, Kurdistan, Kermanshah, Ilam, Hamedan and Lorestan) in Iran. This study was carried out to better characterise the total phenolic and flavonoid contents, antioxidant capacity and phenolic composition, as well as to evaluate the correlation between content of phenolic compounds and antioxidant activity in 10 genotypes of Bene. The antioxidant activity of leaf extracts was measured using different assays: ferric reducing antioxidant power, nitric oxide radical scavenging and 2,2-diphenyl-1-picrylhydrazyl. The results indicated that the antioxidant capacity can be related to total phenolic and flavonoid content, so that among all the genotypes studied here, the highest and the lowest phenolic content and antioxidant activity were observed in B2 and B10 genotypes, respectively. Analysing the phenolic composition using high performance liquid chromatography, caffeic acid, vanillic acid, ferulic acid and sinapic acid were found in all investigated genotypes.
Reservoir Characterization Applying Residual Gas Saturation Modeling, Example From the Starfak t1 Reservoir, Middle Miocene Gulf of Mexico
Creators: name: Holtz, Mark H.
Publisher: name: The University of Texas at Austin
Year: 2005
Subjects: Reservoir characterization
Gas saturation

description: Because of a complex interplay between faulting, stratigraphy, and water drive, it is often difficult to determine original and remaining gas volumes inproduced Miocene offshore Northern Gulf of Mexico gas reservoirs. Faults can be numerous, and their throws can often be too small to detect using conventional 3D seismic analysis. These faults can also be sealing, forming reservoir-flowcompartments, or nonsealing faults that die out within the reservoir. The fluvial-deltaic depositional environment, along with unconformable valley fills,multiplies this reservoir complexity because it produces both flow barriers and widely varying petrophysical properties. These complexities result in multiple gas-water contacts and a wide range of residual gas saturation to water influx,thus rendering difficult gas volume calculations. The hypothesis of this work is that this difficulty can be overcome by developing empirical residual nonwetting phase functions that can be applied within a geocellular reservoir model derived from integrating geologic,geophysical, and engineering concepts. An example of such a model is given for the Starfak T1 reservoir, offshore Louisiana. An integrated reservoir characterization approach was taken with anemphasis on developing an empirical model for calculating maximum residual gas saturation (Sgrm). A method was created for calculating Sgrm based on interrelationships between petrophysical properties. The model is developed as a function of porosity, permeability, capillary pressure, and initial water saturation.With a Delaunay cell representing an ideal pore, pore geometry characteristics were generated that represent a theoretical basis for the Sgrm model. The pore geometry character in the form of pore body to pore throat aspect ratio was determined for varying porosity in the ideal pore. The Sgrm model was then compared with wireline log analysis in an aquifer-swept versus upswept zone and applied in a three-dimensional (3D) geocellular model. To calculate Sgrm in gas reservoirs, a new empirical model was developed. The model is a function of porosity. Results show that in a porous medium containing primary intergranular porosity, as porosity decreases the aspect ratio increases, thus increasing Sgrm through the likely mechanism of snapoff. Further, an equation was developed that determines residual nonwetting phase saturation as a function of aspect ratio. Comparison of wireline gas saturation calculated from original versus aquifer-flushed zones further corroborates the porosity-Sgrminverse relationship. Additionally, a new practical crossplot was developed based on the inverse Sgrm – porosity character that facilitates the recognition of aquifer-swept zones. It is also shown that applying the Sgrm model when integratingseismic data into a geocellular model can help guide this integration through improved material balance.
Phase Behavior Study of Hydrocarbon-Water-Alcohol Mixtures
Creators: name: Bang, Vishal
Publisher: name: The University of Texas at Austin
Year: 2005
Subjects: Phase behavior
Reservoir condition

description: Experiments were performed to study the phase behavior of gas condensate hydrocarbons at reservoir conditions. Constant composition measurements were done on synthetic gas condensate mixtures and the results were used to regress the Peng-Robinson equation-of-state with the temperature-dependent Peneloux volume corrections and classical van der-Waals mixing rule (PR78 Peneloux (T)). Experiments were performed to study the effect of water and methanol on the phase behavior of gas condensate hydrocarbons. Effects of various factors including temperature, pressure and the molar concentrations of water and methanol on the phase behavior of hydrocarbon-water-methanol mixtures were studied. Addition of methanol increased the liquid volume fraction and the dew point pressure when added to the hydrocarbon mixture. However, for hydrocarbon-water-methanol mixtures the aqueous phase volume fraction increased while the dew point pressure decreased with increasing mole fraction of methanol. PR78 Peneloux (T) equation of state was used to model hydrocarbon-water-methanol mixtures. The EOS was regressed to match the experimental data by tuning the binary interaction coefficients between components and their volume shift parameters. The mixtures were also modeled using Peng-Robinson equation of state with temperature-dependent Peneloux volume shift correction factors and Huron-Vidal mixing rules (PR78 Peneloux (T)-HV). The calculations from both the EOS models agree quantitatively with the experimental results. The binary interaction parameters were found to be temperature dependent. The binary interaction parameters and the temperature-dependent volume shift parameters are the key parameters to model these complex mixtures using any EOS model. The multiphase flash capability of PVTSim software by Calsep Inc. was used to calculate the phase diagrams since the phase behavior is sometimes three-phase liquid-liquid-vapor under the experimental conditions. Phase behavior experiments were also performed on hydrocarbon-water-iso-propanol (IPA) mixtures to investigate the effects of iso-propanol on the phase behavior of gas condensate hydrocarbons. The results show that IPA decreases the aqueous phase volume fraction and increases the liquid hydrocarbon phase volume fractions when compared to the analogous hydrocarbon-water-methanol mixtures. Finally, the effect of fluorosurfactants FC4432 and S10 on the phase behavior of gas condensate hydrocarbon-water-methanol mixtures was studied experimentally.
Development and Application of a Drilling Hydraulics Simulator Including Pressure and Temperature Dependent Fluid Density and Rheology Behavior
Creators: name: Leonard, Benjamin Ames
Publisher: name: The University of Texas at Austin
Year: 2006
Subjects: Hydraulics simulator
Fluid density

description: Determination of pressure while circulating is one of the basic drilling engineering tasks. Pressure must be kept below the maximum ratings of tubulars and equipment, and at the surface, the pumps driving the flow must be able to operate at the pressure required to generate the desired flow rate. In the annular space, the fluid pressure must be kept in the planned range to avoid a kick or damaging the formation. This thesis describes the creation and theory of a drilling hydraulics simulator to calculate pressure using standard drilling engineering inputs, operational parameters, and earth properties. As many of the properties of the circulating fluid are dependent on temperature and pressure, it is necessary to include these property variations at any point to create a realistic pressure profile. The simulation solves for the pressure, temperature and fluid density at every point using API pressure calculations, a finite difference numerical solution for a fixed volume energy balance, and density interpolation from tabular data, respectively. The three calculations include the other properties and are thus dependent on each other. Each property is solved separately using an initial guess for the other two properties or the previous step’s calculations’ results. The simulation iterates through calculating the three properties until the values converge from one step to the next. The final hydraulics program is then used to investigate the effect of changing various inputs. The changes in temperature, pressure, and fluid density are examined in various test cases. The effects of the uncertainty in the convective heat transfer coefficients are tested, as are the inclusion of a booster pump and the changing of cuttings volume.
Wanna Get Away? Regression Discontinuity Estimation of Exam School Effects Away from the Cutoff
Creators: name: Angrist, Joshua D.
name: Rokkanen, Miikka
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: 60506 Virology
subject: FOS: Biological sciences
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Science Policy
subject: Mathematics
subject: FOS: Mathematics
subject: Biological Sciences
subject: Sociology
subject: FOS: Sociology
subject: Earth and Environmental Sciences
subject: Biotechnology

description: In regression discontinuity (RD) studies of applicants who face an award or admissions cutoff, causal effects are nonparametrically identified for those near the cutoff. The effect of treatment on inframarginal applicants is also of interest, but identification of such effects requires stronger assumptions than those required for identification at the cutoff. This paper discusses RD identification away from the cutoff. Our identification strategy exploits the availability of dependent variable predictors other than the running variable. Conditional on these predictors, the running variable is assumed to be ignorable. This identification strategy is used to study effects of Boston exam schools for inframarginal applicants. Identification based on RD-specific conditional independence assumptions produces reasonably precise and surprisingly robust estimates of the effects of exam school attendance on inframarginal applicants. These estimates suggest that the causal effects of exam school attendance for 9th grade applicants with running variable values well away from admissions cutoffs differ little from those for applicants with values that put them on the margin of acceptance. An extension to fuzzy designs is shown to identify causal effects for compliers away from the cutoff.
Determining the Fracture Mechanics Properties of Sedimentary Rocks Using Double Torsion Testing
Creators: name: Adefashe, Hammed Adewale
Publisher: name: The University of Texas at Austin
Year: 2006
Subjects: Fracture mechanic
Torsion testing

description: Fracture toughness, stress corrosion limit and subcritical index are important fracture mechanics properties that control unstable and stable crack propagation in rocks. In the petroleum industry, they are important input parameters for hydraulic fracture design, wellbore stability analysis, and geomechanical modeling of fracture networks. Experiments were performed using the double torsion test methodology on sandstone formations (Bromide, Nugget, Scioto, Stump, Travis Peak) and the Austin Chalk to determine the relationship between fracture toughness and subcritical index and their dependence on test environment and rock mineralogy and texture. A strong linear correlation was observed between fracture toughness and subcritical index, suggesting the stronger a rock, the less susceptible it is to stress corrosion cracking. Experiments were also conducted in an attempt to measure the stress corrosion limit in rock. Propagation velocities were measured down to 10-9 m/s, which was the limit of the test apparatus, with no indication of any stress corrosion limit. The average stress intensity factor at the measurement limit was about 0.6 times the fracture toughness, indicating the true limit must be less than 0.6. For the sandstones, fracture toughness scaled inversely with porosity. Subcritical index also decreased with porosity, but the clay-rich sample deviated from the trend of the quartz and calcite cemented sandstones. Microcracks were introduced to the specimens by heating specimens slowly to 500 ̊C. All rocks showed a systematic reduction in P-wave velocity when subjected to a heating cycle with a maximum temperature over 200 ̊C. Velocity measurements in three orthogonal directions suggested that the thermally generated microcracks were randomly oriented. Fracture mechanics tests showed that toughness was systematically reduced by increased microcracking, but subcritical index behavior was more erratic, increasing in some samples and decreasing in others.
The isolation and structural elucidation of three new biflavonoid glycosides from Lomatogonium carinthiacum
Creators: name: Bagenna Bao
name: Qinghu Wang
name: Xiaolan Wu
name: Wenquan Tai
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Science Policy
subject: Biological Sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Molecular Biology
subject: Cell Biology
subject: Engineering
subject: Biochemistry
subject: Biophysics

description: Three biflavonoid glycosides, named carinoside B, C and D (1, 2 and 3, respectively), were isolated from the n-BuOH crude extract of the aerial part of Lomatogonium carinthiacum (Wulfen) Rchb (L. carinthiacum). The structures of 1, 2 and 3 were elucidated by spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.
Intestinal Spirochetosis: To Treat or Not to Treat
Creators: name: Ho, Kimberly
name: Xu, Joseph
name: Katz, Seymour
name: A. Sarkar, Suparna
name: Ullah, Ateeqa Mujeeb
Publisher: name: PRIME
Year: 2024
Subjects: classificationCode: 320220
subject: Pathology (excl. oral pathology)
classificationCode: 320211
subject: Infectious diseases
classificationCode: 320209
subject: Gastroenterology and hepatology

description: AbstractSpirochete colonization of the gastrointestinal tract is a poorly understood phenomenon presenting with varying signs and symptoms. Due to the lack of a unified approach and its varying presentations, the management decision for intestinal spirochetosis (IS) has always been challenging. While metronidazole is the commonly preferred antimicrobial treatment, it remains unclear if therapeutic intervention is indicated for everyone, especially asymptomatic patients. We present three patients, diagnosed with IS. They presented with varying demographics, clinical presentations, and past medical histories and underwent different clinical managements. Our decisions for treatment not only included presenting symptoms but also factors like history of pre-existing gastrointestinal diseases, age, and immune status.
Finite field transport response of a dilute magnetic topological insulator based Josephson junction
Creators: name: Mandal, Pankaj
name: Taufertshöfer, Nicolai
name: Lunczer, Lukas
name: Stehno, Martin P.
name: Gould, Charles
name: Molenkamp, Laurens W.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Hybrid samples combining superconductors with magnetic topological insulators are a promising platform for exploring exotic new transport physics. We examine a Josephson junction of such a system, based on the dilute magnetic topological insulator (Hg,Mn)Te and the type II superconductor MoRe. In the zero and very low field limit, to the best of our knowledge, the device shows, for the first time, induced supercurrent through a magnetically doped semiconductor, in this case a topological insulator. At higher fields, a rich and hysteretic magnetoresistance is revealed. Careful analysis shows that the explanation of this behaviour can be found in magnetic flux focusing stemming from the Meissner effect in the superconductor, without invoking any role of proximity induced superconductivity. The phenomena is important, as it will ubiquitously co-exist with any exotic new physics that may be present in this class of devices.
description: This document is the unedited Author's version of a Submitted Work that was subsequently accepted for publication in Nano Letters, copyright \c{opyright} 2022 American Chemical Society after peer review. To access the final edited and published work see doi.org/10.1021/acs.nanolett.1c04903
Quantum control of molecules for fundamental physics
Creators: name: Mitra, D.
name: Leung, K. H.
name: Zelevinsky, T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The extraordinary success in laser cooling, trapping, and coherent manipulation of atoms has energized the efforts in extending this exquisite control to molecules. Not only are molecules ubiquitous in nature, but the control of their quantum states offers unparalleled access to fundamental constants and possible physics beyond the Standard Model. Quantum state manipulation of molecules can enable high-precision measurements including tests of fundamental symmetries and searches for new particles and fields. At the same time, their complex internal structure presents experimental challenges to overcome in order to gain sensitivity to new physics. In this Perspective, we review recent developments in this thriving new field. Moreover, throughout the text we discuss many current and future research directions that have the potential to place molecules at the forefront of fundamental science.
description: Perspective article
An empirical equilibrium model of formal and informal credit markets in developing countries
Creators: name: Wang, Fan
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Economics (econ.GN)
subject: FOS: Economics and business
subject: G.3; J.4
subject: 91G30, 91G15, 91B69, 90C23, 90C59, 62P20

description: I develop and estimate a dynamic equilibrium model of risky entrepreneurs' borrowing and savings decisions incorporating both formal and local-informal credit markets. Households have access to an exogenous formal credit market and to an informal credit market in which the interest rate is endogenously determined by the local demand and supply of credit. I estimate the model via Simulated Maximum Likelihood using Thai village data during an episode of formal credit market expansion. My estimates suggest that a 49 percent reduction in fixed costs increased the proportion of households borrowing formally by 36 percent, and that a doubling of the collateralized borrowing limits lowered informal interest rates by 24 percent. I find that more productive households benefited from the policies that expanded borrowing access, but less productive households lost in terms of welfare due to diminished savings opportunities. Gains are overall smaller than would be predicted by models that do not consider the informal credit market.
Performance of Gravity Driven and Centrifugal Down-Hole Gas Separators for Continuous and Intermittent Flow
Creators: name: Bohorquez, Renato
Publisher: name: The University of Texas at Austin
Year: 2006
Subjects: Intermittent flow
Gas separator

description: Gas entering the pump is one of the most common causes of decreased efficiency in a sucker rod pumped well or any pumping system. A way to combat this problem is the installation of a down-hole gas separator, also known as a gas anchor at the bottom of the pump. Unfortunately inefficient gas anchors are common and an acceptable guide for optimum gas anchor design does not exist. A gas anchor is composed of an outer barrel (known as the mud anchor) and an inner small diameter tube (known as the dip tube) that is connected to the pump inlet. The produced liquid and some of the gas enter the separator through entry ports on the mud anchor. Inside the separator the produced liquid flows down to the dip tube suction. The gas bubbles in the separator, depending on their size, either flow up and leave through vent holes or flow down into the dip tube suction. Four different gas anchor designs were tested in a laboratory well at the University of Texas production engineering facility. Three of the gas anchor designs are gravity driven gas separators (where gravity separates the gas from the liquid), and thefourth design is a static centrifugal gas separator named the Twister (where centrifugal forces separate the gas from the liquid). Testing was conducted in continuous flow, as that corresponding to a progressing cavity pumped well, and in intermittent flow, as in a sucker rod pumped well.Intermittent flow was obtained by opening and closing an automated valve. The intermittent flow conditions during testing simulated a pumping speed of 10 strokes per minute. The effect of four variables: separator entry port geometry, annular space inside the separator, liquid production rate, and gas rate entering the well, were analyzed. Previous laboratory studies7, 9 undertaken within this project confirm that when the pump inlet is below the perforations all the gas will be separated in the casing and no gas anchor is needed. Also if the gas anchor inlets are in front of the perforations theseparation efficiency is significantly better than when the gas anchor inlets are above the perforations. The new results for intermittent flow, show, that for the conditions in the laboratory well, the entry port geometry did not have a significant impact on the separator efficiency. Also the efficiency of all gravity driven separators was limited by the liquid velocity inside the separator annulus. When the liquid velocity inside the separator averaged approximately 6 in/s or less, complete gas separation was observed. On the other hand, the centrifugal separator had a significantly larger capacity. The most efficient gravity separator achieved complete gas separation at liquid production rates as high as 250 BPD, while the Twister did so up to 390 BPD.
The impact of risk factors for psychosis on the dopamine system
Creators: name: Dahoun, Tarik
Publisher: name: Imperial College London
Year: 2018

description: Risk factors are thought to dysregulate dopamine function leading to the positive psychotic symptoms of schizophrenia. The most common genetic variants affecting the DISC1 gene are associated with schizophrenia, but it is not known if they influence the dopamine system. Evidence indicates that childhood trauma sensitises the dopamine system to increase the effect of later challenges, such as amphetamine. However, it is not known if childhood trauma interacts with amphetamine on dopamine release to induce psychotic symptoms. My first hypothesis was that the DISC1 serine 704 allele (rs821616) was associated with increased dopamine synthesis using [18F]-DOPA PET. Healthy participants DISC1 serine 704 homozygotes exhibited increased striatal dopamine synthesis relative to cysteine 704 carriers, supporting the hypothesis. My second hypothesis was that the DISC1 alleles serine 704 (rs821616), leucine 607 (rs6675281) and arginine 264 (rs3738401) showed increased dopamine receptor levels, using [11C]-(+)-PHNO PET. There was no association between these polymorphisms and striatal dopamine receptor levels in healthy volunteers, refuting the hypothesis. My final hypothesis was that there was an interaction between striatal dopamine release and childhood trauma to increase dexamphetamine-induced psychotic symptoms in healthy participants, using [11C]-(+)-PHNO. Neither childhood trauma nor dopamine release in isolation were predictors of dexamphetamine-induced psychotic symptoms, but a significant interaction was observed between these two variables, supporting the hypothesis. These studies showed 1) that a genetic risk variant is associated with dopamine synthesis but that other variants affecting the gene are not associated with dopamine receptor levels; 2) that induced-psychotic symptoms depend on the interaction between childhood trauma and ventral striatal dopamine release. This is consistent with the theory that a common action of risk factors for schizophrenia is to dysregulate dopamine synthesis and release, but not receptors. Further work is needed to examine how these risk factors affect dopamine function in clinical populations.
Assessment of Shoulder-Bed, Invasion, and Lamination Effects on Borehole Sonic Logs
Creators: name: Peyret, Aymeric-Pierre Bernard
Publisher: name: The University of Texas at Austin
Year: 2007
Subjects: Sonic log
monopole

description: We quantify the relative effects of shoulder beds, layer thickness, invasion, and sand-shale laminations on monopole and dipole borehole sonic logs. This is accomplished through numerical simulation of sonic waveforms that includes all of the propagation modes within the 1−10kH z range. Numerical simulations assume infinitesimal monopole and dipole sources as well as an array of infinitesimal receivers deployed in close similarity with one commercially available wireline sonic tool. Propagation modes and their velocities are assessed via slowness-time-coherence processing of the simulated waveforms.For the case of shoulder-bed and layer-thickness effects, we consider soft and hard formations bounded by shale layers. The thickness of the formation ischanged to consider cases where transmitter and receivers are completely included in the bed and partially distributed across different beds. Simulations indicate that shoulder- and bed-thickness effects can account for up to 33% variations in theP-wave velocities measured with a monopole source and 31% in the measured S-wave velocities measured with a dipole source compared to those measured across infinitely thick beds.We reproduce the sonic response of sand-shale laminated formations by in-cluding thin shale layers within pay sands. The thickness of shale layers is varied to consider the effect of proportion of sand and shale on the measurements. Simula-tions indicate that shale laminations can account for up to 16.4% variations in the P-velocities measured with a monopole source and up to 3.6% variations in the S-velocities measured with a dipole source with respect to those of effective lamination velocities. Effects of invasion are simulated for the case of water-base mud invading oil-bearing formations. Our simulations indicate that P-wave sonic logs can undergoup to 13% variations due to invasion under realistic assumptions of petrophysical and elastic properties of soft and hard formations
ADMINISTRATOR AND TEACHER PERCEPTIONS AND ATTITUDES ON THE EDUCATIONAL EFFECTIVENESS OF CO-TEACH CLASSES
Creators: name: Warffuel, Mark Edward Jr.
Publisher: name: Zenodo
Year: 2022
Subjects: co-teaching
administrators
teachers
perceptions
attitudes
effectiveness

description: This dissertation had as its objective to discover administrator and teacher perceptions and attitudes on the educational effectiveness of co-teach classes. Research questions were designed to address the problem of practice that students with disabilities (SWD) were achieving academics at a rate far below their general education peers. The findings discovered that administrators and teachers had at times divergent perceptions of what others were doing to support their students in the co-teach. These perceptions then influenced their attitudes (specific actions) they were taking to support SWD learning. This divergence of administrator and teacher perceptions was largely influenced by a lack of communication and planning time between both administrators and co-teachers. This study’s recommendations were developed to remedy and mitigate this gap in communication and planning time that is then causing the co-teach classes to be less effective in meeting the educational needs of SWD.
The hard impact of soft co-ordination: emulation, learning, and the convergence of collective labour standards in the EU
Creators: name: Kahn-Nisser, Sara
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: 60506 Virology
subject: FOS: Biological sciences
subject: Plant Biology
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Science Policy
subject: Sociology
subject: FOS: Sociology
subject: Social Science
subject: Evolutionary Biology

description: ABSTRACTThe article examines whether European countries' collective labour standards are converging and if so why. It presents new data on labour protection in 45 European countries and shows that the EU is a labour standards convergence club. It reviews the soft and hard instruments which the EU adopted in order to promote labour standards. The article models the competition, emulation and learning convergence mechanisms using a spatial econometric approach, and shows that EU countries learn from each other's successes and emulate one another. The article thus presents new evidence of the mixture of domestic and cross-national factors which shape labour standards in Europe. It adds to the growing evidence of countries' spatial dependencies in various policy areas. Most importantly, it provides evidence showing that soft co-ordination is an effective instrument which has had a positive impact on labour standards, and has led to horizontal convergence in the EU.
Ultrasonic extraction of anthocyanin from Clitoria ternatea flowers using response surface methodology
Creators: name: Fui Chin Chong
name: Gwee, Xian Fu
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Plant Biology
subject: FOS: Biological sciences
subject: Hematology
subject: Information and Computing Sciences
subject: Biological Sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Ecology
subject: Chemistry
subject: Biotechnology
subject: Cell Biology

description: The ultrasonic extraction (UE) method of anthocyanin from Clitoria ternatea flowers using response surface methodology (RSM) was performed in this study. By using RSM, the objective is to optimise the extraction yield of anthocyanin from C. ternatea which is influenced by various factors, including the extraction temperature, time, ratio of solvent to solid and ultrasonic power. The empirical model was investigated by performing first-level optimisation in a two-level factorial design with Design Expert 7 software. In comparison with the conventional solvent extraction, UE showed a 246.48% better extraction yield and produced an anthocyanin extract with a radical scavenging activity of 68.48% at the optimised factors of 50°C, 150 min, 15 mL/g and 240 W.
Two new eunicellin diterpenoids from the South China Sea gorgonian Muricella sibogae and their bioactivities
Creators: name: Zhang, Xing-Wang
name: Xu-Li Tang
name: Yuan, Hong-Rui
name: Feng, Dan-Qing
name: Su, Pei
name: Li, Ping-Lin
name: Li, Guo-Qiang
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Biological Sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Biotechnology
subject: Cell Biology

description: A systematic re-study on gorgonian Muricella sibogae from South China Sea yielded 10 eunicellin-based diterpenoids including two new ones, sibogins C and D (1 and 2). Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR, IR and MS) and by comparison with data reported in literatures. All the isolates were tested for cytotoxic and antifouling activities. Compounds 3 and 5 showed significant antifouling activity against the green mussel Perna viridis, and especially 3 was suggested as a potent low-toxic antifouling agent with a large LC50/EC50 value of 18.6. This was the first report on the antifouling activity of the eunicellin-type diterpenoids against the green mussel.
Quantitative Studies of Relative Dip Angle And bed-Thickness Effects on Lwd Density Images acquired in High-Angle and Horizontal Wells
Creators: name: Uzoh, Echezona Anthony
Publisher: name: The University of Texas at Austin
Year: 2007
Subjects: Lwd density
Sedimentary structure

description: Logging While Drilling (LWD) density images acquired in high-angle and horizontal(HA/HZ) wells can reveal much about the sedimentary structure of rock formations penetrated by the well. However, the effect of sedimentary structure on the mea-sured density has only now begun to be explored in detail.This thesis report describes numerical simulations undertaken to quantify the in-fluence of relative dip angle and bed thickness on LWD density images acquired in HA/HZ wells penetrating thinly-bedded formations comprised of alternating sands and shales. Typically, the azimuthal binning scheme used to construct LWD density images divides the tool into 16 azimuthal sectors, each sector subtending an angle of 22.5◦from the center of the tool. Count rate data are binned to angular sectors facing density detectors. Our objective is to assess the effects of adjacent beds on sector density measurements due to finite bed thickness and variable relative dip.We use the Monte Carlo N-Particle (MCNP) transport code to simulate LWD den-sity measurements from several combinations of relative dip angle and bed thickness.Commercial count-rate processing techniques are applied to the short- and long-spaced detector measurements in each sector. The assumed source-sensor configu-ration corresponds to the commercial adnVISION6751LWD nuclear tool designedto operate with an 8.25-in stabilizer in an 8.5-in borehole.Several combinations of relative dip angle and bed thickness indicate that numer-ically simulated density images properly quantify bed thickness, bed density, andrelative dip when the thickness of the bed is larger than two inches and when relative dip angle is larger than 75◦. This conclusion stems from the study of density images constructed with compensated and alpha-processed sector density measurements.Furthermore, our study provides a way to estimate the corresponding depth shifts in true stratigraphic thickness (TST) observed in HA/HZ wells, which are caused by differences in the radial lengths of investigation of the short- and long-spaced sensors included in the tool.We describe a field example of LWD tool response across thinly-bedded formationsin a HA well intended to validate the numerically simulated LWD density measure-ments. Comparison of measured and simulated density images confirms the relia-bility of numerical simulations and their value in assessing petrophysical properties of thinly-bedded rock clastic sequences penetrated by HA/HZ wells.
Shale Membrane Efficiency Experimental Study Using Water-Based Muds
Creators: name: Acevedo, Juan Camilo
Publisher: name: The University of Texas at Austin
Year: 2007
Subjects: Shale Membrane
water-based muds

description: Drilling operations rely heavily on the use of water-based muds. These muds tend to invade the formation and alter the stress state condition of the exposed rock and can lead to instability such as wellbore collapse. In the case of shales, muds that have good membrane efficiencies offer a way to provide more stability. Such muds are, therefore, desired. Oil-based muds have proven to have high membrane efficiencies, however, they are usually more expensive than water-based muds and certainly more toxic to the environment. Water-based muds have historically evidenced low membrane efficiencies; however, innovative water-based muds, now available in the industry, appear to be promising in producing higher efficiencies. The objective of this study was to evaluate the membrane forming performance of four water-based muds using different shale types. The water-based muds tested were Ultradril (MI Swaco), Hydroguard (Baroid), Deepdrill (Newpark) and BHDF (also known as Performax) (Baker Hughes). The shales tested were designated as C3, C4, C5, and Arco China. In this study membrane efficiencies varied between 0% and 7.3%, and were found to depend on both the mud properties and the shale properties (such as porosity). Low porosity shales showed high membrane efficiencies. Correlations of membrane efficiency with other parameters such as mineralogy or shale water activity were inconclusive and need additional data. These water-based mud membrane efficiencies are low compared to those of oil-based muds (up to 52%), as reported by Al-Bazali (2005).
Development and Testing of a Discrete Element Model of Crushing Sand
Creators: name: Jurgens, Matthew
Publisher: name: The University of Texas at Austin
Year: 2007
Subjects: Discrete element model
Sand

description: Crushing sands play a significant role in many oilfield phenomena and applications such as subsidence and compaction, permeability reduction, sand production, and drill bit efficiency. Numerical methods can help to better understand the process of crushing and tailor engineering decisions in which crushing is involved. This thesis describes the development and testing of a discrete element model of crushing sand. Sand grains are represented by networks of bonded, rigid particles that behave according to simple spring theory at their contacts, and this material is calibrated to the elasticity and statistical strength of quartz grains. Groups of these agglomerates are then inserted into testing cells where they are stressed to observe the macroscopic and grain scale evolution of crushing in hydrostatic and biaxial compression.
Statistically Partitioning of Well Logs and Core Measurements to Detect and Quantify Petrophysical Properties
Creators: name: Vrubel, Nathan Kyle
Publisher: name: The University of Texas at Austin
Year: 2007
Subjects: Petrophysical property
Well log

description: The subsurface is a mixture of geologic rock constituents such as sandstones, carbonates,and shales, among others. Well logs can indirectly identify these rock constituents. Mostinterpretation methods used in log analysis require some form ofa priorior previousknowledge about the physical response of rocks. This thesis developed a new methodof interpreting well log responses that uses statistical properties of the measurements toeliminate the need for a priori geologic knowledge.Well logs or core measurements, represented as a two–dimensional histogram, are mod-eled as a joint normal distribution (JND), also referred to as a two-dimensional Gaussiandistribution. Assuming that the measurements are Gaussian, enables their parametric rep-resentation. A data set with several rock populations fit the model using the superposition of multiple JNDs —one for each population. Each population is assumed to be normallydistributed, or can be transformed into a normal distribution. I use the Microsoft ExcelSolver to minimize the sum of the square errors between measurements and their predic-tions based on statistical populations. This process determines the unknown values of themean, standard deviation, correlation coefficient, and fraction for each population. I thentransform the model into log space, with the use of Bayes’ Theorem, to create a log of theprobability of occurrence for each population.This method provides a computationally efficient way to identify rock populations, withoutprevious geologic knowledge. A desktop computer, with two 2 GHz processors and threeGB RAM, can optimize 5,000 ft of well log data in less than one minute. I then use thestatistical model to quantify the probability of a geologic population. I test the model usinga combination of synthetic data with known parameters. It is found that the correlationof the populations only impacts the interpretation of highly correlated data. Applicationof the method to a variety of field data produces results consistent with standard well–loginterpretation procedures and core measurements.
Development of High-Performance Surfactants for Difficult Oils
Creators: name: Zhao, Ping
Publisher: name: The University of Texas at Austin
Year: 2007
Subjects: Oil
Interfacial tension

description: Several novel surfactants have shown excellent performance in tests using several crude oils that have properties, such as high wax content, that make high oil recovery with surfactants very difficult. High carbon-number, internal olefin sulfonates, when used with appropriate co-surfactants, co-solvents and alkali, produced the type of phase behavior and ultra-low interfacial tension needed for almost 100% oil recovery from laboratory core experiments. These surfactants could be used at both low and high temperatures and showed low retention in cores. This work demonstrates how the performance of both surfactant-polymer and alkaline-surfactant-polymer floods can be dramatically improved at the same or lower costs associated with conventional surfactants and co-solvents and at a wider range of reservoir conditions viiiThe identification of high-performance surfactants suitable for high-temperature and/or paraffinic oil applications opens up the potential to recover a vast amounts of additional oil outside the range of conditions considered practical in the past. High carbon number internal olefin sulfonates gave good performance at low concentrations and were found to be compatible with both polymers and alkali such as sodium carbonate. The identification of high-performance surfactants suitable for high-temperature and/or paraffinic oil applications opens up the potential to recover a vast amount of additional oil outside the range of conditions considered practical in the past.
Kinetics of Gas Hydrate Formation and Dissociation
Creators: name: Schmitt, Alexander David
Publisher: name: The University of Texas at Austin
Year: 2008
Subjects: Gas hydrate formation
Hydrates

description: A consistent method was developed to monitor the rate of formation and dissociation of hydrates. The method consisted of monitoring pressure and temperature over time, and visually documenting the presence of hydrates inside a fixed volume high pressure cell and extracting hydrate samples from the cell. The effect of various types and concentrations of surfactants and foaming agents on the formation and dissociation of gas hydrates was investigated. The surfactants tested were sodium dodecyl sulfate, cetyl trimethyl ammonium bromide (CTAB) and Aerosol AY. Foaming appeared to have a limited effect on the rate of hydrate formation. Some surfactants appeared to significantly increase the rate of hydrate formation and decrease nucleation time. This would be beneficial in any process that required purposefully producing gas hydrates. Hydrates produced with surfactants were much more homogeneous than those formed with gas and water alone, and appeared to grow from the edge of the cell inwards rather than randomly. Two surfactants, CTAB and Aerosol AY, appeared to act as hydrate inhibitors at relatively low concentrations, suggesting they could be used to prevent hydrate formation in pipes and equipment. Hydrate nucleation time appeared to be a stochastic process, and there was no significant evidence that trials with numerous “freeze periods” had decreased nucleation time, or significantly altered hydrate formation.
Chirality-Induced Noncollinear Magnetization and Asymmetric Domain-Wall Propagation in Hydrogenated CoPd Thin Films
Creators: name: Wang, Wei-Hsiang
name: Pan, Ching-Yang
name: Liu, Chak-Ming
name: Lin, Wen-Chin
name: Jiang, Pei-hsun
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Array-patterned CoPd-based heterostructures are created through e-beam lithography and plasma pretreatment that induces oxidation with depth gradient in the CoPd alloy films, breaking the central symmetry of the structure. Effects on the magnetic properties of the follow-up hydrogenation of the thin film are observed via magneto-optic Kerr effect microscopy. The system exhibits strong vertical and lateral antiferromagnetic coupling in the perpendicular component between the areas with and without plasma pretreatment, and asymmetric domain-wall propagation in the plasma-pretreated areas during magnetization reversal. These phenomenon exhibit evident magnetic chirality and can be interpreted with the Ruderman-Kittel-Kasuya-Yosida coupling and the Dzyaloshinskii-Moriya interaction (DMI). The sample processing demonstrated in this study allows easy incorporation of lithography techniques that can define areas with or without DMI to create intricate magnetic patterns on the sample, which provides an avenue towards more sophisticate control of canted spin textures in future spintronic devices.
description: Supplementary materials available at https://pubs.acs.org/doi/10.1021/acsami.1c23276#notes-1