Chemical Engineering Commons^™

Physicochemical Characterization Of Safranal-Β-Cyclodextrin Inclusion Complexes Prepared By Supercritical Carbon Dioxide And Conventional Methods., Sanaz Abbaszadegan

Theses

Saffron (Crocus sativus. Linn) has attracted much attention over the last decade because it has a large number of potent and biologically active compounds such as crocin, crocetin, picrocrocin and safranal. Researchers have shown that safranal has high antioxidant and cytotoxicity activities against several types of tumour cells (e.g., hepatocellular carcinoma) both in-vitro and in-vivo. However, the low aqueous solubility of safranal prevents using it as a therapeutic or preventive agent.

β-cyclodextrin (β-CD) inclusion complexes are being used in pharmaceutical applications to alter physicochemical properties (e.g., solubility, volatility, stability, chemical reactivity, and bio-availability) of poorly water soluble drugs. Thus the …

Modeling The Effect Of Apc Truncation On Destruction Complex Function In Colorectal Cancer Cells, Dipak Barua, William S. Hlavacek

Chemical and Biochemical Engineering Faculty Research & Creative Works

In colorectal cancer cells, APC, a tumor suppressor protein, is commonly expressed in truncated form. Truncation of APC is believed to disrupt degradation of β-catenin, which is regulated by a multiprotein complex called the destruction complex. The destruction complex comprises APC, Axin, β-catenin, serine/threonine kinases, and other proteins. The kinases CK1α and GSK-3β, which are recruited by Axin, mediate phosphorylation of β-catenin, which initiates its ubiquitination and proteosomal degradation. The mechanism of regulation of β-catenin degradation by the destruction complex and the role of truncation of APC in colorectal cancer are not entirely understood. Through formulation and analysis of a …

Atomic Layer Deposited Highly Dispersed Platinum Nanoparticles Supported On Non-Functionalized Multiwalled Carbon Nanotubes For The Hydrogenation Of Xylose To Xylitol, Xinhua Liang, Chengjun Jiang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Highly dispersed platinum nanoparticles were deposited on gram quantities of non-functionalized multiwalled carbon nanotubes (MWCNTs) by atomic layer deposition (ALD) in a fluidized bed reactor at 300°C. (Methylcyclopentadienyl) trimethylplatinum and oxygen were used as precursors. The results of TEM analysis showed that ∼1.3 nm Pt nanoparticles were highly dispersed on non-functionalized MWCNTs. The porous structures of MWCNTs did not change with the deposition of Pt nanoparticles. For comparison, the commercial 3 wt.% Pt/C catalyst was also characterized. The ALD-prepared Pt/MWCNT was used for the hydrogenation of xylose to xylitol. The ALD-prepared Pt/MWCNT showed the best catalytic performance with 100 % …

Automated Methods To Determine Electrospun Fiber Alignment And Diameter Using The Radon Transform, Nicholas J. Schaub, Sean J. Kirkpatrick, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Recent evidence demonstrates the ability to change cell function by altering the physical properties of electro spun scaffolds, but many studies still do not characterize electro spun fiber alignment and diameter. To aid in the reporting of these crucial properties, we demonstrate two methods of quantifying electro spun fiber alignment with one method capable of determining electro spun fiber diameter. The first method assesses fiber alignment in a scanning electron microscopy image using the Radon Transform (RT) to calculate the entropy of the fibers in the image. The RT entropy method was more sensitive than a commonly used Fast Fourier …

Slab Flattening Trigger For Isotopic Disturbance And Magmatic Flareup In The Southernmost Sierra Nevada Batholith, California, Alan D. Chapman, Jason B. Saleeby, John Eiler

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The San Emigdio Schist of Southern California permits examination of partial melting and devolatilization processes along a Late Cretaceous shallow subduction zone. Detrital and recrystallized zircon of the structurally highest portions of the schist bracket the depositional age to between ca. 102 and 98 Ma. Zircon oxygen isotope data from both lower-plate schist and upper-plate assemblages of the Sierra Nevada batholith (SNB) reveal a δ18O shift of ̃1.5% between igneous (̃5.5%) and recrystallized (̃7%) domains. These results, taken with previous zircon and whole-rock δ18O measurements, provide evidence for devolatilization and/or partial melting of the schist and fluid ascent through overlying …

Batch And Continuous Production Of Stable Dense Suspensions Of Drug Nanoparticles In A Wet Stirred Media Mill, Afolawemi Afolabi

Dissertations

One way to improve the bioavailability of poorly water-soluble drugs is to reduce particle size of drug crystals down to nanoscale via wet stirred media milling. An increase in total surface area per mass loading of the drug and specific surface area as well as reduced external mass transfer resistance allow a faster dissolution of the poorly-water soluble drug from nanocrystals. To prevent aggregation of nanoparticles, polymers and surfactants are dissolved in water acting as stabilizers via adsorption onto the drug crystals.

In the last two decades, ample experimental data were generated in the area of wet stirred media milling …

Pressure Swing Membrane Absorption Process For Separation Of Low Temperature Post-Shift Reactor Syngas, John Chau

Dissertations

This thesis is concerned with a cyclic pressure swing membrane absorption process (PSMAB) for separation of the feed gas mixture containing —40% CO₂-He balance using pure ionic liquid, 1-butyl-3-methylimidazolium dicyanamide ([bmim][DCA]), and its solution containing poly(amidoamine) (PAMAM) dendrimer Gen 0 primarily with a dry feed gas. An advanced pressure swing membrane absorption process is developed to produce purified He as a surrogate for H₂ at a high pressure from simulated low- temperature shifted syngas for different membrane modules. The PSMAB process also simultaneously produces a highly purified CO₂ stream containing bulk of the CO₂ in …

Superior Dna Transport System, David Dickinson, Dr. William Pitt

Journal of Undergraduate Research

Cancer is one of the leading causes of death worldwide. Although surgeries and chemotherapy have had limited success, these techniques are largely unable to solve the problem and may cause significant damage to a patient’s entire body. Some patients are killed by the chemotherapy. Since many cancers have been found to be caused by the lack of a protein due to mutated DNA, a plasmid DNA carrying a replacement for this gene may be able to solve the problem. P52 is one of the more famous missing proteins, but others have and will continue to be discovered. If DNA could …

Electrosynthesis Of Glycerol Carbonate From Co2 And Glycerol, Huan Wang, Mei-Xia Zhu, La-Xia Wu, Xiao-Ming Xu, Xue-Ru Zhao, Jia-Xing Lu

Journal of Electrochemistry

Glycerol carbonate was obtained from glycerol and carbon dioxide under room temperature and normal pressure by electrochemical method. The effects of synthesis conditions, such as cathode, charge, current density and temperature, on the reaction of glycerol and carbon dioxide have been investigated. The yields of 73% were produced by electrosynthesis of carbonate under the optimized condition, which is much higher than that by common catalysis method. The electrochemical behavior of the reaction system has been studied by cyclic voltammetry, through which the reaction process has been proposed.

Influence Of Pretreatment On Electrocatalytic Property For Methanol Oxidation Of Ptru/Wc, Xiao-Ling Lang, Mei-Qin Shi, Ye-Kun Jiang, Chun-An Ma

Journal of Electrochemistry

The surface of tungsten carbide (WC) was treated by potassium hydroxide (KOH) at different pH values for different time. The PtRu/WC composite was prepared by microwave-assisted polyol method. The phase structure of PtRu/WC composites were characterized by XRD. The electrocatalytic activity was tested by cyclic voltammetry and chronoamperometry. The results indicated that with different pH treatments WC became more readily supported on PtRu. When treating WC in KOH at pH = 14, PtRu exhibited the best degree of crystallinity on WC surface, leading to the highest electrocatalytic activity of PtRu/WC. Moreover, the optimized activity of PtRu/WC towards methanol oxidation was …

Synthesis And Electrochemical Properties Of Li(Ni0.5Co0.2Mn0.3)1-2xTiXNbXO2, Yong Tang, Qin-Lin Liao, Xiang-An Guo

Journal of Electrochemistry

The cathode-active materials of layered Li(Ni_0.5Co_0.2Mn_0.3)_1-2xTi_xNb_xO₂（x=0, 0.002, 0.005, 0.01, 0.02）composites were synthesized by the thermal treatment of the coprecipitated precursor at 900 ^oC in air. The effects of Ti-Nb co-dopants on the structural and electrochemical properties of Li(Ni_0.5Co_0.2Mn_0.3)O₂ were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical experiments. The results show that the small amounts of Ti-Nb co-dopants in Li(Ni_0.5Co_0.2Mn_0.3)O₂significantly decreased the degree of cation mixing in …

Research Progress Of Intermediate Layers In Ti-Based Oxide Anodes, Xiu-Li Song, Hui-Min Yang, Zhen-Hai Liang

Journal of Electrochemistry

Titanium (Ti)-based oxide anodes are excellent anode materials which have been applied widely in electrochemical fields all over the world. Adding intermediate layers in Ti-based oxide anodes can improve the conductivity, lengthen the lifetime and strengthen the stability between Ti base and metal oxides active layers of electrodes. This article reviews the research progress of intermediate layers in Ti-based oxide anodes. At the same time, current problems existed in the field of Ti-based oxide anodes are pointed out and future development trend in oxide electrode with intermediate layers is prospected.

Advanced Treatment Of Dyeing Wastewater For Reuse By Electrochemical Oxidation, Fei-Xiang Chen, Chu-Yin Yang, Ming-Ming Zhou, Jia-De Wang

Journal of Electrochemistry

In response to the characteristics of dye wastewater, the electrochemical oxidation of effluents from the biochemical process of dyeing wastewater was studied in the electrochemical reactor using PbO₂/Ti electrode as the anode and stainless steel plate as the cathode. The results revealed that the electrochemical oxidation could simultaneously remove the Chemical Oxygen Demand (COD), ammonia and chromaticity. At the residence time of 60 min and current density of 10 mA·cm^-2, the COD, ammonia, chromaticity, concentration of chloride ion and pH values could meet the water standards for “the reuse of urban recycling water-water quality standard for …

Voltage Reversal Behavior In Microbial-Anode Fuel Cells, En-Ren Zhang, Jun-Le Niu, Lei Liu, Guo-Wang Diao

Journal of Electrochemistry

Voltage reversal behavior was investigated in microbial-anode fuel cells (MFCs). Electricity-producing biofilms were developed on the surface of anodes in MFCs inoculated with mixed inoculum from activated sludge. MFC duplicates generally exhibited different performances with respect to the internal resistance, the voltage output and the discharging duration when operating in batch mode. Voltage reversal was observed to occur first in the MFC with lower performance when connecting MFCs in series. Analysis of electrode potentials indicated that the potentials of microbial anodes quickly shifted to more positive values when enhancing discharge current, resulting in voltage reversal in MFCs. Increasing temperature would …

Using Hydrolyzed Sludge Liquor As The Substrate Of Microbial Fuel Cell, Peng Liang, Chao Guo, Xia Huang

Journal of Electrochemistry

Hydrolyzed sludge liquor was used as the substrate of microbial fuel cell. When the thermal treatment time increased from 2 h to 96 h, pH varied little between 7.4 and 8.0. When the treatment time increased, the conductivity, COD and alkaline condition increased to 2.53 mS·cm^-1, 2520 mg·L^-1 and 800 mg·L^-1, respectively. Meanwhile, the power density increased to 25 W·m^-3. The COD removal increased firstly, then decreased, and finally reached the maximum of 47% at the hydrolyzed time of 6 h. The maximal coulombic efficiency was 71% when the treatment time was 4 …

Electrocatalytic Oxidation Degradation Kinetics Of Oxalic Acid In A Cylindrical Electrochemical Reactor With Ti/Iro2-Ta2O5 Anode, Jing Su, Hai-Bo Lin, Hong Xu, Wei-Min Huang, Ya-Peng He

Journal of Electrochemistry

The electrocatalytic oxidation degradation kinetics of oxalic acid in a cylindrical electrochemical reactor with Ti/IrO₂-Ta₂O₅  as an anode was studied. The relation between instantaneous current efficiency and organic concentration in bulk was established based on the two paths for direct electrochemical oxidations, and the theoretical model was verified by experiments. The experimental resultswere reasonably consistent with the established kinetic model. Furthermore, the competition between the two paths was explored with the modelparameter analysis.

Performance Of The Electro-Oxidation And Electro-Fenton Processes With A Bdd Anode For The Treatment Of Low Contents Of Pharmaceuticals In A Real Water Matrix, Sirs Ignasi, Antonio Garrido Jos, Brillas Enric

Journal of Electrochemistry

Here, we report the performance of electro-oxidation and electro-Fenton with a boron-doped diamond (BDD) anode for the treatment of single and multicomponent solutions containing small amounts of pharmaceutical residues (i.e., 1 mg·L^-1 paracetamol and/or 1 mg·L^-1 salicylic acid) spiked into a real water matrix at pH 3.0. Electro-oxidation was performed in a BDD/Pt cell, whereas electro-Fenton was carried out in a BDD/air-diffusion cell to electrogenerate H₂O₂ at the cathode, always operating at constant current density. It was found that the decay of both pharmaceuticals by electro-oxidation was more rapid in the real water matrix than …

A Multi-Physics Model For Solid Oxide Iron-Air Redox Flow Battery: Simulation Of Discharge Behavior At High Current Density, Meng Guo, Xuan Zhao, Ralph E. White, Kevin Huang

Faculty Publications

A rigorous physics-based mathematical model for a solid oxide iron-air redox flow battery system is presented in this paper. The modeled flow battery system combines a Fe-FeO redox couple as the energy storage unit and a regenerative solid oxide fuel cell as the electrical functioning unit in a 2D axial symmetric geometry. This model was developed from fundamental theories of reaction engineering in which basic transport phenomena and chemical/electrochemical kinetics are included. The model shows good agreement with the experimental data. Simulation results for the chemical, electrochemical and transport behavior of the battery are discussed.

Characterization Of Biomass Fuel Properties Based On Functional Groups, Richard B. Reid, Dr. Larry Baxter

Journal of Undergraduate Research

The search for sustainable energy sources and technologies is one of the world’s primary concerns in the 21st century. Biomass energy is projected to be an important component of a diverse and sustainable energy portfolio. In order to utilize this source effectively there must be accurate composition data and predictive correlations for material properties. Though the literature provides some empirical correlations of fuel properties such as heating value [Jenkins et al 1996], fundamental chemical and structural analyses have not been explicitly correlated with such properties. This project has sought to establish relationships between fuel properties and chemical functional group contributions …

Char Combustion And Late Burnout Reactivity, Rhett Brewer, Dr. William Hecker

Journal of Undergraduate Research

To study the effects of the carbon structure on coal reactivity during the late stages of combustion, it was necessary to be able to know what effect mineral content had on the reactivity. Two coals, dietz (high mineral content) and pitt 8 (low mineral content), were chosen for the experiment so that their behavior during the late stages of combustion could be compared.