Chemical Engineering Commons^™

Supercritical Fluid Aided Microencapsulation Of Dry Powders, Raquel Carvallo

USF Tampa Graduate Theses and Dissertations

Coating of fine particles to produce tailored surface properties is currently a key development for supercritical fluids applications, in different areas such as: pharmaceutical, nutraceutical, cosmetic, agrochemical, electronic and specialty chemistry industries. During the encapsulation process the particles surface can be designed with specific properties by spreading a thin film coating material over the surface of the particles.

Chitosan, a natural polymer, was used in this work as the encapsulant material. Chitosan is biocompatible, biodegradable to normal body constituents, safe, non-toxic, bacteriostatic, anticancerogen, and versatile polymer. These attributes are among the properties that make Chitosan an attractive component of pharmaceutical …

Evaluation Of The Physicochemical Properties And Stability Of Solid Lipid Nanoparticles Designed For The Delivery Of Dexamethasone To Tumors, Melissa Howard

University of Kentucky Doctoral Dissertations

Pre-clinical and clinical trials suggest that pre-treatment with dexamethasone (Dex) may facilitate enhanced uptake of subsequently administered chemotherapeutic agents. To reduce the side effects associated with systemic administration of Dex, solid lipid nanoparticles (SLNs) containing dexamethasone palmitate (Dex-P) were prepared as a means of achieving tumor-targeted drug delivery. These studies were aimed at evaluating the physicochemical properties and both the physiological and storage stability of the SLNs.

SLNs were prepared using nanotemplate engineering technology. Stearyl alcohol (SA) was used as the lipid phase with Brij^® 78 and Polysorbate 60 as surfactants and PEG6000 monostearate as a long-chain PEGylating agent. …

New Catalysts For The Photocatalytic Reduction Of Carbon Dioxide To C1 Organic Compounds, Anna Hailey

Honors Theses

Photocatalytic reduction of carbon dioxide (CO2) has recently been identified as one of the five notable research areas in catalysis because it simultaneously reduces carbon emissions while storing clean, green solar energy in organic compounds. The development of efficient photocatalysts that take advantage of solar radiation is therefore an important area of research. Titanium dioxide (TiO2) is a commonly-used photocatalyst for this reaction, but it requires ultraviolet (UV) radiation to excite its electrons. Carbon-doping (C-doping) has been shown to reduce the intensity of energy required, thus allowing the photocatalyst to take advantage of the visible light spectrum. Copper (Cu), added …

Flotation Circuit Performance Determination Using Size By Size Recovery – Case Of Bulyanhulu Gold Mine, Savinus Maronga

Tanzania Journal of Engineering and Technology (TJET)

The Bulyanhulu rougher flotation circuit performance has been determined by establishing the performance of individual cells. Direct sampling was done on all the rougher cell input, output and size analysis was performed on the samples with material in each size fraction assayed for copper and gold to determine their recoveries. It was observed that the performance of rougher cell number 3 and 4 was poor compared to other cells especially for finer particles below 53 µm where the recoveries were below 60%. In the last two flotation cells recoveries of both metals was very good (above 90%) in all particle …

An Integrated Approach For Phytate Degradation And Recovery Of Myo-Inositol And Phosphate As Valued-Added Products From The By-Products Of Corn Ethanol Industry, Jun Dang

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

An integrated process was developed to hydrolyze the phytates in light steep water (LSW) and to simultaneously isolate inorganic phosphate (Pi) and myo-inositol products. The proposed integrated process is helpful in resolving the environmental and nutritional concerns in the use of corn gluten feed (CGF) in the animal diets. This process comprised of partial and total hydrolysis of LSW and intermediate anion exchange separation technique. The phytates in LSW were initially degraded to negatively charged myo-inositol phosphates (InsP₂ - InsP₅). The optimized experimental parameters for the partial hydrolysis of LSW were determined to be 2 h hydrolysis …

Purification Of Synthetic Oligomers, Shiyue Fang

Michigan Tech Patents

This invention provides a novel method for purifying synthetic oligomers comprising capping, polymerizing and separating any failure sequences produced during oligomer synthesis. Either the failure sequence or the full-length oligomer may be polymerized. Optionally, small molecule impurities may also be incorporated into the polymerized material. The invention provides novel capping agents having a polymerizable functional group. The invention also provides kits comprising at least one composition of the present invention.

The Effects Of Electricity Pring On Phev Competitiveness, Shisheng Huang, Bri-Mathias S. Hodge, Farzad Taheripour, Joseph F. Pekny, Gintaras V. Reklaitis, Wallace E. Tyner

PPRI Digital Library

Plug-in Hybrid Electric Vehicles (PHEVs) will soon start to be introduced into the transportation sector, thereby raising a host of issues related to their use, adoption and effects on the electricity sector. Their introduction has the potential to significantly reduce carbon emissions from the transportation sector, which has led to government policies aimed at easing their introduction. If their wide-spread adoption is set as a target it is imperative to consider the effects of existing policies that may increase or decrease their adoption rate. In this study, we present a micro level electricity demand model that can gauge the effects …

Process To Produce High Surface Area Nanoparticle Vanadium Phosphorus Oxide Catalyst And Product Derives Thereof, Yun Hin Taufiq-Yap, Ali A. Rownaghi

Chemical and Biochemical Engineering Faculty Research & Creative Works

An improved process to produce high surface area nanoparticle vanadium phosphorus oxide catalysts comprises the steps of reducing vanadium-containing compounds in an alcohol solution selected from the group consisting of isobutanol and benzyl alcohol and any combination derives thereof under reflux for 4 to 6 hours to form a suspended mixture; reacting dopants and phosphorus-containing compounds to the suspended mixture under reflux for 30 minutes to 3 hours to form precursors of the vanadium phosphorus oxide catalysts; drying the formed precursors; and calcining the dried precursors in a flow of gaseous n-butane/air mixture at 400 to 460° C. to form …

A Review Of The Benefits And Applications Of The Thorium Fuel Cycle, Vincent Hall

Chemical Engineering Undergraduate Honors Theses

This paper aims to inform the reader of the benefits that can be achieved by using thorium as a fuel for nuclear power. Stages of the thorium cycle are directly compared against the current uranium based nuclear fuel cycle. These include mining, milling, fuel fabrication, use of various reactor designs, reprocessing, and disposal. Thorium power promises several key advantages over traditional nuclear power methods, namely a dramatic decrease in long lived radioactive waste, increased fuel efficiency, greater chemical stability during disposal, and higher adaptability for differing reactor designs across a wider range of the thermal neutron spectrum. Obstacles that face …

Doug Ruthven And Jorg Karger: Their Individual And Collective Contributions To The Field Of Zeolite Science And Engineering, Dhananjai B. Shah

Chemical & Biomedical Engineering Faculty Publications

Prof. Doug Ruthven and Prof. Jörg Kärger are two giants in the field of zeolite science and engineering. Over their academic careers encompassing almost forty years each, they have contributed significantly to the advancement of fundamental understanding of adsorption and diffusion in zeolites as well as their industrial applications. The author, in the beginning of his academic career, had an opportunity to spend two years as a post-doctoral fellow in Prof. Ruthven’s laboratory at the University of New Brunswick (1975–1977). This experience actually motivated me to spend my academic career in working in the field of zeolite adsorption and …

Petroleum Industry Linkages And Nigeria's Economic Development, Chinyere U. Nwolisa, Chinyelu N. Ugoji

Bullion

Nigeria, Africa's most populous country and potentially its largest economy, has witnessed decades of dictatorship and misrule. Accompanying this misrule are severe economic problems of an unprecedented magnitude. This paper intends to add further clues to the solution for this national developmental puzzle. The remaining part of the paper is arranged thus: Part 2 presents an overview of the Nigerian Petroleum industry while the part 3 looks at the literature of economic development the country appears to be executing. Parl4 discusses the various linkages the Petroleum industry offers visa-vis Nigeria's exploration of their potentials. The penultimate part will offer some …

Polymer (Su-8) Optofluidic Device With Embedded Hydrogel Oxygen Sensing Elements, Zhan Gao, David B. Henthorn, Chang-Soo Kim

Chemical and Biochemical Engineering Faculty Research & Creative Works

The SU-8 photopolymer is an excellent alternative for traditional materials used in fluidic devices such as glass- or silicon-Based inorganic materials. We describe a new chemically anchored, lithographically patterned hydrogel sensing element embedded in a completed SU-8 fluidic channel structure after the channel bonding process. Polyethylene glycol (PEG) hydrogel films incorporating oxygen-responsive ruthenium-complex fluorophores are grafted and patterned by photopolymerization of solution-phase precursors on the modified SU-8 channel surface. the optofluidic sensing platform with this embedded sensing elements exhibited excellent performance in measuring dissolved oxygen content. a unique advantage of this method is the selective growth of various functional films …

“Hydraulic Fracturing Efficiency In The Olmos Sand Formation”, Lauren N. Fogarty

Honors Capstones

No abstract provided.

Fibronectin For Use In Hemostats And Wound Stabilization In Trauma, Mohammed Halhouli

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Exploring the phase during wound healing when fibrinogen (FBG) and fibronectin (FN) interact forming a small thin layer for cells to migrate and proliferate at the injury site is necessary for the primary building blocks and initial stages of skin recovery. The aim of this thesis is to illustrate that administrating a reasonable amount of (FN) and FBG, in a semi-organizational technique, to the wound site will encourage cell population and ECM formation, as well as, improve the wound healing process. WE hypothesized that FBG and FN interactions will configure the construction of dermal cells and their final fate to …

Hydrothermal Reduction Synthesis Of Lifepo4 And Its Electrochemical Performance, Hong-Li Zou, Guang-Hui Zhang, Pei-Kang Shen

Journal of Electrochemistry

The cathode materials of LiFePO₄ were prepared via a hydrothermal reduction method using FeCl₃ as Fe source and iron as a reducing agent.The results showed that ferric salt could be reduced to ferrous salt completely under the hydrothermal condition and pure-phase LiFePO₄ was obtained based on the test results of XRD and FTIR.Carbon-coated LiFePO₄ was synthesized by pyrolysisng glucose at high temperature.The morphologies of pure LiFePO₄ displayed cluster-like while the LiFePO₄/C displayed sphere-like particles.The electrochemical test showed that the LiFePO₄/C had good rate performance,while LiFePO₄ delivered much lower discharge capacity.

Effects Of Solvents And Electrolyte Salts On The Electrochemical Reduction Of Oxygen In Non-Aqueous Electrolytes, Yan-Yan Tian, Wei Wu, Jun Gao, Yong Yang

Journal of Electrochemistry

The electrochemical reduction processes of oxygen in different non-aqueous solvents such as acetonitrile(MeCN),propylene carbonate(PC) and their mixtures were investigated by cyclic voltammetry method.The results indicated a one electron reduction of oxygen to O^2-occured in these systems as a first step reduction,no matter whether in tetrabutylammonium hexafluorophosphate(TBAPF₆)/MeCN or TBAPF₆/PC electrolyte.However,the CV curves in 0.1 mol·L^-1 TBAPF₆/MeCN showed a couple of reversible redox peaks,indicating that the reduction process of oxygen was irreversible in the 0.1 mol·L^-1 TBAPF₆/PC electrolyte.In the PC-based electrolyte,the reduction current peak reduced largely and the oxidation peak …

Electrodeposition Of Lead Dioxide From Dluoroborate Solutions, Chun-Mei Kong, Yong-Ming Tang, Wen-Zhong Yang, Xiao-Yuan Yang

Journal of Electrochemistry

The PbO₂ anodes were prepared on platinum from fluoroborate media and its doped solutions by electrodeposition technique.Elecchemical and pysicochemical properties of these PbO₂ films were studied by cyclic voltammetry methods,XRD and SEM.The results showed that the presence of BF₄-increased PbO₂ electrodeposition rate;the prepared lead dioxide consisted of β-PbO₂;the preferential orientation of crystals and surface morphology were affected a lot by doping F-and Fe³⁺.The FB/F-Fe-PbO₂ electrode exhibited regular-shaped layers with compact morphology.Furthermore,increasing current density also change the preferential orientation of PbO₂ crystals.

The Sol-Gel Synthesis And Electrochemical Performance Of Li3V2(Po4)3/C Cathode Material For Lithium Ion Battery, Li-Ying Liu, Lian Chen, Hai-Yan Zhang, Yu-Chun Zhai

Journal of Electrochemistry

Li₃V₂(PO₄)₃/C was synthesized by sol-gel method with citric acid as chelate and C sources. Physical and electrochemical performances of as-prepared materials were characterized through XRD, SEM and galvanostatic charge-discharge tests,etc. The results showed that products produced by calcining at 800 ℃ for 12 h had a single phase crystal structure and relatively small particle sizes with uniform distribution. At 0.1 C, 0.5 C and 1 C, the initial specific discharge capacities were 153.0, 143.1 and 130.6 mAh·g^-1, respectively, and capacity efficiencies were 93.1%, 85.4% and 77.3% after 50 cycles, respectively. …

The Conversion Of Low-Grade Heat Into Power Using Supercritical Rankine Cycles, Huijuan Chen

USF Tampa Graduate Theses and Dissertations

Low-grade heat sources, here defined as below 300 ºC, are abundantly available as industrial waste heat, solar thermal, and geothermal, to name a few. However, they are under-exploited for conversion to power because of the low efficiency of conversion. The utilization of low-grade heat is advantageous for many reasons. Technologies that allow the efficient conversion of low-grade heat into mechanical or electrical power are very important to develop.

This work investigates the potential of supercritical Rankine cycles in the conversion of low-grade heat into power. The performance of supercritical Rankine cycles is studied using ChemCAD linked with customized excel macros …

Enhancing Oxygen Reduction Reaction Activity Via Pd-Au Alloy Sublayer Mediation Of Pt Monolayer Electrocatalysts, Yangchuan Xing, Yun Cai, Miomir B. Vukmirovic, Wei Ping Zhou, Hiroko Karan, Jia X. Wang, Radoslav R. Adzic

Chemical and Biochemical Engineering Faculty Research & Creative Works

New Pt monolayer electrocatalysts were prepared using galvanic displacement of a copper monolayer deposited at underpotentials on a Pd core. by performing underpotential deposition twice, two monolayers were deposited, forming a core-shell structure with double shells. the double shells consist of an outermost shell of Pt monolayer and a sublayer shell of Pd-Au alloy. It was found that by adjusting the compositions of the alloy sublayer, it is possible to mediate the oxygen reduction reaction (ORR) activity of the Pt catalysts. an alloy with 10% (atomic) Au was found to be the most active among the catalysts tested. Furthermore, the …