Chemical Engineering Commons^™

Replacement Options For The Ap1-Lew System, Tiffany M. Sherburn

Honors Theses

This report details the upgrade of Pfizer’s Active Pharmaceutical Ingredient-Low Endotoxin Water (API-LEW) distribution system. The current system is suffering from chloride induced stress corrosion which has caused pitting and cracking throughout the exterior portions of the loop. The system will eventually fail catastrophically if an update is not undertaken. Many variables and system constraints are considered to maintain the API-LEW grade water.

The system operates at 65 ^○C and maintains turbulence to prevent any microbial growth. The distribution loop spans 8,500 feet of 4 inch diameter stainless steel pipe which is carried on trestles that are exterior to …

Template-Free Synthesis Of Porous Nio Hierarchical Structure For High Performance Supercapacitors, Yun Huang, Zhong Wu, Xin-Bo Zhang

Journal of Electrochemistry

A facile and template-free hydrothermal method is proposed to successfully synthesize porous NiO hierarchical structure, which is found to be assembled from ultrathin NiO nanosheets. As for electrochemical pseudocapacitor application, the obtained material exhibits not only high specific capacitances of 435 F·g^-1 at 20 mV·s^-1 and 367 F·g^-1 at 10 A·g^-1, but also holds a good electrochemical stability over 1000 cycles at a current rate of 20 mV·s^-1. These results suggest that the hierarchical structured porous NiO is a promising supercapacitor electrode material.

Electrochemical Reduction Of Co2 On Sn/Cu Electrodes, Chen-Chen Zhao, Jian-Wei Guo, Li Wang, Xiang-Ming He, Cheng Wang, Zhi-Xiang Liu

Journal of Electrochemistry

The Sn/Cu electrodes were prepared by electroplating method and their morphologies under different galvanization current densities were determined by SEM. In alkali, the effects of Sn/Cu electrodes on the activities towards hydrogen evolution and electrochemical reduction of CO₂ were investigated in alkaline solutions using a three-electrode system. These results indicated that the Sn/Cu electrodes prepared at 10 mA/cm² and 15 mA/cm² showed good activities, while that prepared at 15 mA/cm² was even better in activities. The synergetic structure of the Sn/Cu electrode to be beneficial to electrochemical reduction of CO₂ has been pointed out.

Ethanol Electrooxidation On Pt/Mo2/Cnts Catalysts, Yu-Long Cheng, Jie Sun, Ji-Gang Li, Li-Gong Zhang, Tian Zhou, Geng Chang, Zhong-Chao Dong

Journal of Electrochemistry

The ethanol electrooxidation behaviors on Pt/MO₂/CNTs（M=Sn, Ti, Ce）and Pt/CNTs catalysts in H₂SO₄ solutions were researched by cyclic voltammetry. It has revealed that the catalysts with the addition of metal oxides presented higher electrooxidation activity for ethanol, in particular, the Pt/CeO₂/CNTs catalyst showed the best activity for ethanol electrooxidation intermediate. The Pt/SnO₂/CNTs catalyst demonstrated the best ethanol electrooxidation activity when considering the synthetic effects of such parameters as the onset oxidation potential, peak current densities and total oxidation area.

Electrochemical Preparation Of Nanostructural Pt-Ni And Pd-Ni Films For Ethanol Electro-Oxidation, Chen-Zhong Yao, Hui-Xuan Ma, Bo-Hui Wei

Journal of Electrochemistry

The Pt-Ni and Pd-Ni films were successfully prepared on Ti substrates by electrodeposition method. The porous Pt-Ni nanoflakes appeared to be uniform with the thickness of the slices about 10 ~ 20 nm. The porous Pd-Ni nanoparticles with a flower shape appeared to be uniform with the diameters of 50 ~ 60 nm. The XRD patterns also indicated that the Pd-Ni and Pt-Ni nanostructures have the poor crystallinity. The onset potentials of ethanol oxidation were negatively shifted to –0.74 V on Pt-Ni electrodes and –0.71 V on Pd-Ni electrodes, respectively. Addition of Ni could enhance catalytic activities and antitoxic properties …

Electrochemical Properties Of The Keggin-Type Lacunary Heteropolysilicate Anion And Its Eectrocatalysis For H2O2 Reduction, Xi-Long Liu, Chun-Yan Wu, Fang Zhou, Hong-Sheng Liu, Ying-Jie Hua, Chong-Tai Wang, Xiao-Yang Liu

Journal of Electrochemistry

Electrochemical properties of the Keggin-type lacunary heteropolysilicate anion SiW₁₁O₃₉^8- (SiW₁₁) and its indirect electrocatalysis for H₂O₂ reduction in the supporting electrolyte containing 0.1 mol·L^-1 NaHSO₄ and Na₂SO₄ solutions were investigated using cyclic voltammetry, square wave voltammetry and alternating current impedance spectroscopy. Experimental results indicated that SiW₁₁ showed two pairs of reversible redox waves on the glassy carbon (GC) electrode in an acidic solution. The electron transfer number corresponding to the two pairs of waves was one, and the proton transfer number involved was two during …

Synthesis Of Lini0.5Co0.2Mn0.3O2 For Lithium Ion Batteries And The Mechanism Of Capacity Fading At High Temperature, Wen Liu, Miao Wang, Ji-Tao Chen, Xin-Xiang Zhang, Heng-Hui Zhou

Journal of Electrochemistry

The Ni-rich cathode materials, LiNi_0.5Co_0.2Mn_0.3O₂, have been synthesized by Co-precipitation and high-temperature solid-phase sintering method. Constant current charge-discharge tests showed high discharge capacity of 179.2 mAh·g^-1 in the 3.0~4.4 V at 0.2C. However, at 55 °C the LiNi_0.5Co_0.2Mn_0.3O₂ experienced the dramatic capacity fading after 100 charge-discharge cycles. Electrochemical Impedance Spectroscopy, X-Ray Photoelectron Spectroscopy, Atomic Emission Spectroscopy have been employed to study the capacity fading mechanism of LiNi_0.5Co_0.2Mn_0.3O₂ cycled at high temperature in range of high-voltage charge and …

Synthesis And Electrochemical Properties Of Lifeso4F/Graphene Composite As Cathode Material For Lithium-Ion Batteries, Wei Guo, Ya-Xia Yin, Li-Jun Wan, Yu-Guo Guo

Journal of Electrochemistry

The LiFeSO₄F was successfully synthesized from the reactions of FeSO₄∙xH₂O (x=1, 4, 7) with LiF in tetraethylene glycol media through a facile low temperature method. The structures and microscopic features of the products were characterized by XRD, SEM and TEM. TGA result shows the good thermal stability of the as-prepared LiFeSO₄F. No diffraction peaks of the FeSO₄ are observed in the as-prepared products with the starting material of either FeSO₄∙4H₂O or FeSO₄∙7H₂O, which should be ascribed to delaying the release of H_{2 …}

Synthesis And Electrochemical Properties Of Yttrium-Doped Lini0.49Mn1.49Y0.02O4, Xian-Wen Zhang, Zheng-Xi Zhang, Li Yang, Shao-Hua Fang, Long Qu

Journal of Electrochemistry

The LiNi_0.49Mn_1.49Y_0.02O₄ cathode material was synthesized using the citric acid-assisted sol-gel method by partial substitutions of Ni and Mn with Y in the LiNi_0.5Mn_1.5O₄ material. The influences of Y doping on the structure and electrochemical properties were investigated by means of X-ray diffraction, cyclic voltammetry, galvanostatic charge/discharge tests and AC impedance spectroscopy. The results showed that the introduction of Y into the LiNi_0.5Mn_1.5O₄ greatly improved the cycle performance and rate capability. When the charge and discharge current was 1 C in the potential …

Catalytic Activities Of Electrochemically Dealloyed Pt(Pd)-Cu Catalysts For Oxygen Reduction Reaction, Rui-Zhi Yang, Strasser Peter, Toney Michael

Journal of Electrochemistry

The electrochemically dealloyed Pt(Pd)-Cu catalysts were prepared by electrochemical dealloying of Cu₃Pt(Pd) and their catalytic activities toward oxygen reduction reaction (ORR) were studied in 0.1 mol·L^-1 HClO₄ . solutions. The structural features of the dealloyed Pt(Pd)-Cu were revealed by synchrotron-based anomalous X-ray diffraction (AXRD) and surface X-ray scattering (SXS) at an atomic scale. We established a relationship between the structure and the catalytic activity by comparing the ORR activity and the structure of dealloyed Cu₃Pt nanoparticles with similarly dealloyed Cu₃Pt thin films and Cu₃Pt(111). The enhancement in the activity of …

Electrocatalytic Oxidation Of Ethanol On Ni-P-Tio2 Composite Coating Electrodes, Guang-Hui Hu, Hai-Xia Zeng, Zhi-Gang Wei, Zhan-Chang Pan, Shu-Guang Xie, Yan-Di Zou

Journal of Electrochemistry

The Ni-P-TiO₂ composite coating electrodes with different contents of TiO₂ particulates were prepared by electroless plating technique from Ni-P plating bath containing TiO₂ powders on brass. Cyclic voltammetry, linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS) were used to test the electrochemical performance of Ni-P-TiO₂/Cu electrodes. It was indicated that the Ni-P-TiO₂/Cu electrodes exhibited very strong electrocatalytic activity toward the oxidation of ethanol in alkaline medium at ambient temperature. The electrocatalytic activity of ethanol oxidation on the Ni-P-TiO₂ electrodes depended on the amounts of TiO₂ in the coatings. The …

Impact Of Sludge Treatment Processes On Estrogen Concentration In Wastewater Sludge, Erica Marti

College of Engineering: Graduate Celebration Programs

Endocrine-disrupting compounds (EDCs), such as estrogen, are known to be present in the aquatic environment at concentrations that affect fish and other wildlife. For example, juvenile male fish exposed to estrogen will synthesize vitellogenin, which is a female-specific protein. Estrogen exposure is also linked to sex reversal, intersexuality, and inhibition of gonadal growth (Jobling et al., 1996).

Wastewater treatment plants are major contributors of EDCs into the environment. EDCs end up in wastewater as a result of natural excretion from the body or being washed off the skin. WWTPs are not designed to remove these substances. As a result, EDCs …

One-Dimensional-Turbulence Simulation Of Flame Extinction And Reignition In Planar Ethylene Jet Flames, David O. Lignell, Devin Rappleye

Faculty Publications

A series of three simulations of temporally evolving, planar, nonpremixed ethylene jet flames are performed using the one-dimensional-turbulence (ODT) model. The simulations are performed at a fixed Reynolds number, but varying Damköhler numbers, under conditions that result in significant flame extinction and reignition. Results are compared to corresponding direct numerical simulations (DNSs), which exhibit 40, 70, and nearly 100% peak flame extinction among the three cases. The planar, temporal configuration is ideal for comparison and validation of the ODT model, and identical thermodynamic, transport, and kinetic models were used. The ODT model captures the jet evolution and heat …

Fermentation And Supercritical Extraction Studies Of Açaí Berry, Rosanna Iris Ayala

USF Tampa Graduate Theses and Dissertations

The açaí berry has grown in popularity for dieters and the health conscious. The berry contains high levels of antioxidants. The main anthocyanins are cyanidin-3-rutinoside and cyanidin-3-glucoside. The berries also contain vitamins and nutrients that help boost energy and alertness, and fatty acids that help maintain normal cholesterol levels. As a result of the health benefits of the constituents, the berries are chosen for obtaining the active ingredients by extraction.

The solids left over after extraction still contain nutrients and useful components. There is a possibility of fermenting this residual and creating an açaí berry wine. Açaí berry wine is …

New Approaches In Automation, Allen Lam

Hong Kong Innovative Users Group Meetings

No abstract provided.

Chemical Potential Perturbation: Extension Of The Method To Lattice Sum Treatment Of Intermolecular Potentials, Stan G. Moore, Dean R. Wheeler

Faculty Publications

The recently developed chemical potential perturbation (CPP) method [S. G. Moore and D. R. Wheeler, J. Chem. Phys. 134, 114514 (2011) https://doi.org/10.1063/1.3561865.] is extended to the lattice (Ewald) sum treatment of intermolecular potentials. The CPP method predicts chemical potentials for a range of composition points using the local (position-dependent) pressure tensor of an inhomogeneous system. When computing the local pressure tensor, one can use the Irving-Kirkwood (IK) or Harasima (H) contours of distributing the pressure. We compare these two contours and show that for a planar interface, the homogeneous pressure and resulting chemical potential can be approximated with …

Multi-Processor Computation Of Thrombus Growth And Embolization In A Model Of Blood-Biomaterial Interaction Based On Fluid Dynamics, Brandon Thomas Andersen

Theses and Dissertations

This work describes the development and testing of a real-time three-dimensional computational fluid dynamics simulation of thrombosis and embolization to be used in the design of blood-contacting devices. Features of the model include the adhesion and aggregation of blood platelets on device material surfaces, shear and chemical activation of blood platelets, and embolization of platelet aggregates due to shear forces. As thrombus develops, blood is diverted from its regular flow field. If shear forces on a thrombus are sufficient to overcome the strength of adhesion, the thrombus is dislodged from the wall. Development of the model included preparing thrombosis and …

State Of Charge And Loss Of Active Material Estimation Of A Lithium Ion Cell Under Low Earth Orbit Condition Using Kalman Filtering Approaches, Saeed Khaleghi Rahimian, Sean Rayman, Ralph E. White

Faculty Publications

The state of charge (SOC) and the loss of active material of the electrodes of a Li ion cell under Low Earth Orbit condition (LEO) have been estimated using Kalman filtering methods, by means of the physics-based single particle (SP) model. Zero mean Gaussian noise was added to the charge-discharge curves obtained by the SP model to generate synthetic data. Afterwards, nonlinear Filtering approaches including Extended Kalman Filtering (EKF) and Unscented Kalman Filtering (UKF) were applied to predict the true SOC and the electrodes’ degradation, by minimizing the measurement residuals between the model prediction and the synthetic data. The results …

On The Measurement Of Gas Holdup Distribution Near The Region Of Impeller In A Gas-Liquid Stirred Rushton Tank By Means Of Γ-Ct, Li Na Kong, Wei Li, Lu Chang Han, Yue Jin Liu, He An Luo, Muthanna H. Al Dahhan, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three Flow Patterns of Flooding, Loading and Complete Recirculation in a Gas-Liquid Stirred Rushton Tank Were Identified based on Experimental Observation. the Gas-Liquid System Was Composed of Air and Water. under Different Operating Conditions of Gas Flow Rate and Impeller Rotating Speed, the Distribution of Gas Holdup Near the Region of Impeller Was Measured using a Γ-CT Scan Method. Both Quantitative Digital Distribution Curves of Gas Holdup and their Qualitative Color CT Images Were Obtained. at the Region of Impeller, There Was a Convex Characteristic Peak of Gas Holdup Distribution Both in Radial and in Axial Directions, and with the …

Systems And Devices For Isothermal Biochemical Reactions And / Or Analysis, Robert W. Doebler Ii, Christopher Cooney, Anna Hickerson, James D. Sterling, Ali Nadim

Business and Information Technology Faculty Research & Creative Works

An isothermal reaction and analysis system may include a receiver to receive sample holders, a thermal control sub system to control a temperature of the receiver, an excitation Subsystem, a detection Subsystem and an analysis Subsystem. Excitation Sources and/or detectors are positioned to enhance data collection. Sample holders may include filters, selectively blocking and passing wavelengths or bands of electromagnetic radiation.