Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for +publisher:"University of Texas – Austin" +contributor:("Liljestrand, Howard M. (Howard Michael)"). Showing records 1 – 3 of 3 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


University of Texas – Austin

1. -3182-5510. Further model development and application of UTCHEM for microbial enhanced oil recovery and reservoir souring: Further model development and application of University of Texas Chemical Compositional Simulator for microbial enhanced oil recovery and reservoir souring.

Degree: MSin Engineering, Environmental and water resources engineering, 2016, University of Texas – Austin

This research presents an improved simulator to predict the enhanced oil recovery after applying microbial enhanced oil recovery (MEOR) technique and the onset of reservoir souring in sea-water injected reservoirs. The model is developed to study the effect of temperature, salinity, and pH on the growth of bacteria which are responsible for producing in-situ bioproducts in MEOR and causing microbial reservoir souring. The effects of environmental factors (i.e., pH, salinity, and temperature) are implemented into a four-phase chemical flooding reservoir simulator (UTCHEM). In the MEOR process, nutrients and natural bacteria are injected into a reservoir and both indigenous and injected microorganisms are able to react and then generate bioproducts based on in-situ reactions. In this study, we considered three different mechanisms proposed for MEOR: biosurfactant-dominated MEOR, biopolymer-dominated MEOR, and biomass-dominated MEOR. Results show that in-situ bioproduct generation rates can be thoroughly modeled based on environmental factors. Simulation results show 10-15% incremental oil recovery using in-situ biosurfactant compared to waterflooding, biopolymer can increase the oil recovery by 3%, and biomass can contribute to oil production by increasing the recovery by 6%. The simulation results show that nutrient concentration, salinity, and temperature are the most significant parameters influencing oil recovery, whereas pH has an insignificant effect. Reservoir souring is a phenomenon that occurs because of in-situ biodegradation reactions and is modeled in the present study. Sulfate-reducing bacteria (SRB) can convert sulfate ions into hydrogen sulfide by oxidizing a carbon source. This phenomenon is called reservoir souring when it occurs in water-flooded reservoirs. The generated H2S content affects the properties of rocks, reduces the value of produced hydrocarbon, causes corrosion in production facilities, and has health and safety issues. Because of the severity of the problem, several attempts have been made to model and predict the onset of souring. However, there are high uncertainties because of many inestimable and uncertain parameters (e.g., biodegradation parameters, sulfate concentration, reservoir pH, salinity, and temperature). Therefore, the capability of UTCHEM for calculating the maximum growth rate in terms of temperature, salinity, and pH helped us to show the environmental effect on the process. We also investigated the effect of maximum growth rate and available sulfate on the biodegradation process that leads to reservoir souring. In summary, our results show that the microbial reservoir souring process can be modeled based on environmental factors. More importantly, the results show the high sensitivity of the process to different parameters. Advisors/Committee Members: Liljestrand, Howard M. (Howard Michael) (advisor), Sepehrnoori, Kamy, 1951- (advisor), Lashgari, Hamidreza (committee member).

Subjects/Keywords: Microbial enhanced oil recovery; Biodegradation; Reservoir souring

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

-3182-5510. (2016). Further model development and application of UTCHEM for microbial enhanced oil recovery and reservoir souring: Further model development and application of University of Texas Chemical Compositional Simulator for microbial enhanced oil recovery and reservoir souring. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/41608

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Chicago Manual of Style (16th Edition):

-3182-5510. “Further model development and application of UTCHEM for microbial enhanced oil recovery and reservoir souring: Further model development and application of University of Texas Chemical Compositional Simulator for microbial enhanced oil recovery and reservoir souring.” 2016. Masters Thesis, University of Texas – Austin. Accessed April 06, 2020. http://hdl.handle.net/2152/41608.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

MLA Handbook (7th Edition):

-3182-5510. “Further model development and application of UTCHEM for microbial enhanced oil recovery and reservoir souring: Further model development and application of University of Texas Chemical Compositional Simulator for microbial enhanced oil recovery and reservoir souring.” 2016. Web. 06 Apr 2020.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-3182-5510. Further model development and application of UTCHEM for microbial enhanced oil recovery and reservoir souring: Further model development and application of University of Texas Chemical Compositional Simulator for microbial enhanced oil recovery and reservoir souring. [Internet] [Masters thesis]. University of Texas – Austin; 2016. [cited 2020 Apr 06]. Available from: http://hdl.handle.net/2152/41608.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Council of Science Editors:

-3182-5510. Further model development and application of UTCHEM for microbial enhanced oil recovery and reservoir souring: Further model development and application of University of Texas Chemical Compositional Simulator for microbial enhanced oil recovery and reservoir souring. [Masters Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/41608

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete


University of Texas – Austin

2. Dozier, Celina Susie-Marie. Alumina-titania particles for the heterogeneous photocatalytic oxidation of ciprofloxacin.

Degree: PhD, Environmental and water resources engineering, 2016, University of Texas – Austin

The global presence of xenobiotic organic compounds, such as pharmaceuticals and personal care products (PPCPs), in drinking water supplies and wastewater effluents has raised concerns regarding their potential effects on aquatic life, human health, and antibacterial resistance. Traditional treatment systems, not specifically designed to target removal of these compounds, vary with respect to their ability to remove PPCPs. Therefore, research focused on the development and optimization of treatment processes that can remove PPCPs is warranted. Advanced oxidation processes (AOP) have been shown to be effective at degrading a number of pharmaceuticals. These processes are defined by the production of radicals, such as superoxide and hydroxyl radicals, which are highly reactive and can, therefore, oxidize target contaminants more effectively than common oxidants such as ozone and ultraviolet (UV) light. One such AOP is photocatalysis, in which the radicals are created by the illumination of a photocatalyst. Photocatalysis has been previously demonstrated for degradation of the antibiotic ciprofloxacin, the selected pharmaceutical in this research. In this work, the impact of sorption on the photocatalysis of ciprofloxacin was studied by developing a mixed phase photocatalyst that optimized sorption. Titanium dioxide (TiO2) is a commonly used photocatalyst. However, TiO2 particles have limited surface area and varying affinity for ciprofloxacin as a function of pH. Aluminum oxide (Al2O3) was chosen as the sorbent to mix with the TiO2 due to its ability to sorb ciprofloxacin over the pH range of natural waters and its ability to prevent the recombination of photo-generated electron-hole pairs, which are vital for the production of hydroxyl radicals. The particles were synthesized using pure TiO2 and other particles that ranged in aluminum oxide content (68% - 100% by mass) using a sol-gel process to achieve high surface areas. The 100% TiO2 particle was pure anatase, while the mixtures and the 100% Al2O3 particle consisted gamma-alumina and anatase when the titania was present. Sorption was found to be pH dependent for both Al2O3 and TiO2 with maximum adsorption at pH 6 and 7, respectively. The synthesized particles resulted in linear equilibrium sorption constants at fixed pH that varied with alumina content, with the 90% alumina material adsorbing the most at pH 8 due to its high surface area. Photocatalysis using the synthesized particles under UV irradiation at 365 nm effectively oxidized ciprofloxacin and the rates were faster than photolysis, but slower than the standard photocatalyst Degussa P25 TiO2 and synthesized pure TiO2. Sorption followed the Langmuir isotherm and oxidation followed first order kinetics if the assumption of low concentration (relative to the Langmuir sorption coefficient) was applied, typical of environmental conditions. Experiments revealed that rapid exchange of ciprofloxacin with pure TiO2 occurred as rate constants determined from aqueous phase concentrations were comparable to rate… Advisors/Committee Members: Katz, Lynn Ellen (advisor), Liljestrand, Howard M. (Howard Michael) (advisor), Lawler, Desmond (committee member), Speitel, Jerry (committee member), Stevenson, Keith (committee member).

Subjects/Keywords: Photocatalysis; Ciprofloxacin; Hydroxyl radicals

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Dozier, C. S. (2016). Alumina-titania particles for the heterogeneous photocatalytic oxidation of ciprofloxacin. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/40263

Chicago Manual of Style (16th Edition):

Dozier, Celina Susie-Marie. “Alumina-titania particles for the heterogeneous photocatalytic oxidation of ciprofloxacin.” 2016. Doctoral Dissertation, University of Texas – Austin. Accessed April 06, 2020. http://hdl.handle.net/2152/40263.

MLA Handbook (7th Edition):

Dozier, Celina Susie-Marie. “Alumina-titania particles for the heterogeneous photocatalytic oxidation of ciprofloxacin.” 2016. Web. 06 Apr 2020.

Vancouver:

Dozier CS. Alumina-titania particles for the heterogeneous photocatalytic oxidation of ciprofloxacin. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2016. [cited 2020 Apr 06]. Available from: http://hdl.handle.net/2152/40263.

Council of Science Editors:

Dozier CS. Alumina-titania particles for the heterogeneous photocatalytic oxidation of ciprofloxacin. [Doctoral Dissertation]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/40263

3. -8331-8951. Development of reference materials for cement paste and mortar : calibration of rheological measurements.

Degree: MSin Engineering, Architectural Engineering, 2018, University of Texas – Austin

This thesis presents the results of five interrelated projects conducted to advance the progress of studies in concrete workability. Specifically, work conducted towards the development and certification of Standard Reference Materials (SRMs) for cement paste and mortar rheometers are presented in this work. Other SRMs developed at NIST have served a multitude of services, but these SRMs target the concrete industry by providing a way for commercially available rheometers to be calibrated economically and with good accuracy. However, problems regarding reproducibility of the paste SRM, microbial contamination of the paste SRM, and accuracy of measurement have limited the development of the concrete SRM. Thus, this thesis includes studies that were conducted to address these issues. In Project 1, the SRM preparation method was modified to improve reproducibility. The major outcome of this project was the development and re-certification of a standard reference material for cement paste. This recertification includes new rheological characteristics and statistical analyses. The goal of Project 2 was to extend the shelf life of the SRM since it was discovered that after 10 days the rheological properties of the SRM was not stable It was found that use of biocides, such as sodium propionate, extends the stability of the SRM. In Project 3, the development and certification of a SRM for mortar is provided with rheological properties and statistical analyses. Description of a model that was developed to predict the behavior of the SRM is also provided. In Project 4, a literature review regarding why industrial rheometers experience slippage issues was conducted. Key findings were that slippage issues depends on the rheometry choice and boundary conditions (free surfaces). Project 5 presents the results of a critical analysis conducted to evaluate the effect of rheometry systems for calibrating mortar-type rheometers. Rheological behaviors of two SRMs were measured experimentally and the results were compared to a computer simulation models. Discussion on the best rheometry system to avoid slippage is provided in that project. Overall, the outcomes of the work conducted in fulfillment of this thesis serve as the initial steps towards developing a reference material for concrete rheometers. Advisors/Committee Members: Ferron, Raissa D. (advisor), Liljestrand, Howard M. (Howard Michael) (advisor), Ferraris, Chiara (committee member).

Subjects/Keywords: Rheology; Reference materials; Biocide; Microorganisms; Microbes; Slippage; Rheometry; Calibration; Flow curves; Viscosity; Bingham; Mortar; Suspensions

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

-8331-8951. (2018). Development of reference materials for cement paste and mortar : calibration of rheological measurements. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/68038

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Chicago Manual of Style (16th Edition):

-8331-8951. “Development of reference materials for cement paste and mortar : calibration of rheological measurements.” 2018. Masters Thesis, University of Texas – Austin. Accessed April 06, 2020. http://hdl.handle.net/2152/68038.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

MLA Handbook (7th Edition):

-8331-8951. “Development of reference materials for cement paste and mortar : calibration of rheological measurements.” 2018. Web. 06 Apr 2020.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-8331-8951. Development of reference materials for cement paste and mortar : calibration of rheological measurements. [Internet] [Masters thesis]. University of Texas – Austin; 2018. [cited 2020 Apr 06]. Available from: http://hdl.handle.net/2152/68038.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Council of Science Editors:

-8331-8951. Development of reference materials for cement paste and mortar : calibration of rheological measurements. [Masters Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/68038

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

.