Engineering Commons^™

Biosignatures In Mars Analog Acid Salt Lakes, Sarah Stewart Johnson, M. L. Soni, D. J. Collins, Kathleen C. Benison, Melanie R. Mormile, M. G. Chevrette, B. L. Ehlmann

Biological Sciences Faculty Research & Creative Works

Paleolake sites on Mars, particularly buried deposits that have been shielded from surface radiation, serve as intriguing targets for the search for life. Mars-like ephemeral playa lakes here on Earth can offer insights and perspectives on the possibilities for physical, metabolic, and biomolecular biosignature recovery from similar environments on Mars.

Carbon Dioxide Capture By Steel-Making Residues In A Fluidized Bed Reacto, Suhaib Mohammad Hameedi

Theses

Global warming is one of the most challenging problems facing societies these days, and it is known to be caused by the increasing emissions of Green House Gases (GHG's), mainly CO₂, from various human activities. To solve such a problem, or at least minimize its effects, several actions have been considered. One of these actions is carbon capture, which has many different options and techniques. This research focuses on the capture of CO₂ through reactions with steel-making residues, an alkaline solid by-product of the steel-making process. The aim is to sequester CO₂ and form carbonates, which …

An Analysis Of Capital Cost Estimation Techniques For Chemical Processing, Omar Joel Symister

Theses and Dissertations

This research serves to compare the use of the capital cost estimation software, Aspen Capital Cost Estimator (ACCE), with other capital cost estimating methods specifically the module costing technique outlined by Richard Turton et al. and also a factorial costing technique outlined by Gavin Towler and Ray Sinnott. This study will compare popular process equipment found in the chemical process industries. The relationship between the capacities of the equipment, as it relates to the cost as well as operational pressures and materials of construction (MOC), will also be obtained and compared. The results of this study may be used by …

Cloning, Fed-Batch Expression And Purification Of A Novel Anti-Candida Peptide And Development Of A Cleavage Resistant Variant Of Green Fluorescence Protein, Rudra Palash Mukherjee

Graduate Theses and Dissertations

This work illustrates that the intelligent design of a bioprocess for the production of peptides of various length is possible by having a prior knowledge of desired product, cell line, fermentation conditions, and choices for downstream recovery. Cloning, expression, and recovery of a novel 12-mer anti-Candida peptide served as an illustrative case for a proposed Escherichia coli platform. The antifungal peptide, expressed as a fusion to GFPUV during high call density fed-batch, was recovered from cell lysate, concentrated using ion exchange chromatography, and finally cleaved with cyanogen bromide. The platform was capable of producing active peptide capable of arresting the …

Preparation And Performance Of 3d Graphene Type Porous Carbon Employing Nano Fe(Oh)3 As Template For Oxygen Reduction Catalyst, Chong-Yun Sun, Zhong-Fang Li, Xue-Wei Lu, Xi-Zhan Zhong, Yu-Rong Liu

Journal of Electrochemistry

The 3D graphene type porous carbon was prepared using coal tar pitch as carbon source and nano Fe(OH)₃ as template. Optimal conditions for the catalytic oxygen reduction performance were determined as: the mass ratio of coal tar, nano Fe(OH)₃ and KOH is 6:8:4; the pyrolysis temperature is 800 ^oC. SEM images show that the products have uniformly porous structure. TEM images demonstrate that the products are porous with foam shapes. HRTEM images further indicate that the products have formed several-layers 3D graphene structure, which are also supported by XRD and Raman data, and the pore size mainly …

Special Issue: Electrocatalyst And Electrocatalysis In Fuel Cells Preface, Zi-Dong Wei

Journal of Electrochemistry

/

Recent Progress In Non-Precious Metal Oxygen Reduction Reaction Catalysts With An Encapsulation Structure, Mei-Ling Xiao, Jian-Bing Zhu, Chang-Peng Liu, Jun-Jie Ge, Wei Xing

Journal of Electrochemistry

Platinum-based materials, the state-of-the-art catalysts for fuel cells, suffer from prohibitive costs, limited resources and insufficient durability. Accordingly, tremendous efforts were made in searching for efficient, durable and inexpensive alternatives to precious-metal electrocatalysts for the oxygen reduction reaction (ORR). Transition-metals (Fe, Co)/nitrogen co-doped hybrids, heteroatom (N, P, S, F, et al) doped carbons and composites with transition-metals encapsulated in graphitic layers are reported as the most efficient non-precious metal ORR catalysts. Among the various non-precious metal ORR catalysts, transition-metals encased in graphitic layer catalysts are a novel type of catalysts for ORR with high activity and durability, and thus, the …

Mini-Review: Possible Applications Of Scanning Electrochemical Microscopy (Secm) In Characterizations Of Oxygen Reduction Reaction And Oxygen Evolution Reaction, Xing-Xing Chen

Journal of Electrochemistry

Scanning electrochemical microscopy (SECM) has been proved to be a unique technique for combinatorial screening of localized phenomena for different electrocatalysts potentially used in new energy conversion and storage systems. This mini-review provides a brief summary of different SECM working modes, such as direct mode, feedback mode, generation-collection mode, redox competition mode and noise mode, which are especially applied for characterizing the oxygen reactions. Particularly, a series of important development in SECM screening of electrocatalysts for oxygen reduction reaction and oxygen evolution reaction from the author and W. Schuhmann’s group in Germany has been highlighted and overviewed. Finally, some prospects …

Multi-Scaled Carbon Supported Platinum As A Stable Electrocatalyst For Oxygen Reduction Reaction, Yu-Ping Li, Lu-Hua Jiang, Su-Li Wang, Gong-Quan Sun

Journal of Electrochemistry

The stability of carbon supports is essential for electrocatalysts of fuel cells. Herein, the mesoporous carbon with the high graphitic degree (highly graphitic mesoporous carbon, HGMC) was synthesized by using resorcinol as the carbon precursor, SiO₂ as the templates and urea as the reducing agent. The as-prepared HGMC was characterized by XRD, Raman spectroscopy, TEM, N2 adsorption. The stability of HGMC was evaluated by mimicking the start-up/shut-down conditions of fuel cells in a three-electrode system referring to the NREL standard. The obtained HGMC is of moderate surface area (187.4 m²•g^-1) and is chemically stable under …

Recycling Mf Solid Waste Into Mesoporous Nitrogen-Doped Carbon With Iron Carbide Complex In Graphitic Layers As An Efficient Catalyst For Oxygen Reduction Reaction, Can-Yun Zhao, Lin Huang, Yong You, Ying-Fang Yao, Xiao-Gang Su, Hong Wan, Jian-Guo Liu, Cong-Ping Wu

Journal of Electrochemistry

Nitrogen-doped carbon materials with iron ions are known as catalytic growth agents for the oxygen reduction reaction (ORR) in fuel cells, but the design and synthesis of high-performance and low-cost catalysts still remain a significant challenge. Herein, we present a cost-effective approach to dispose of MF solid waste as the precursor for the synthesis of MCFes catalyst with the favorable structure features such as the high specific surface area, abundant active sites and suitable pore structure. The results showed that the MCFe-10/10/2 had specific surface area as high as 780.7 m²•g^-1 and high efficient catalytic activity comparable …

Recent Progresses In Molybdenum-Based Electrocatalysts For The Hydrogen Evolution Reaction, Ze-Xing Wu, Jie Wang, Jun-Po Guo, Jing Zhu, De-Li Wang

Journal of Electrochemistry

Electrochemical catalytic production of hydrogen has been considered as a promising and sustainable strategy for clean and renewable energy technologies. Molybdenum-based non noble metal catalysts for the hydrogen evolution reaction have attracted extensive attention due to its effective catalytic performance. In this review, the recent progresses in molybdenum-carbide, phosphide, nitride and sulfide electrocatalysts are presented. In addition, the strategies to improve the catalytic performance are analyzed and the prospects for the future development trends are expected.

Syntheses Of Carbon Paper Supported High-Index Faceted Pt Nanoparticles And Their Performance In Direct Formic Acid Fuel Cells, Long Huang, Mei Zhan, Yu-Cheng Wang, Yan-Fen Lin, Shuo Liu, Ting Yuan, Hui Yang, Shi-Gang Sun

Journal of Electrochemistry

Direct formic acid fuel fuels (DFAFCs) are promising energy source for portable electronic devices. Palladium (Pd) is more active than platinum (Pt) for the formic acid electrooxidation. However, the stability of Pd is much poorer than that of Pt. Unfortunately, the ultra-low natural abundance of the Pt makes it extremely expensive and limits its application as a fuel cell catalyst. Boosting both the activity and stability of Pt nanoparticles to enhance their efficiency is urgent. As previous works illustrated, nanoparticles enclosed with high-index facets usually bare a higher activity toward fuel cell related reactions than those nanoparticles with low-index facet. …

Dynamic Simulation Of Oxygen Reduction Reaction In Pt/C Electrode For Proton Exchange Membrane Fuel Cells, Shang Li, Fen Zhou, Lei Chen, Mu Pan

Journal of Electrochemistry

It is an urgent need to reduce the Pt loading in electrode for practical fuel cell applications worldwide. Herein, we theoretically investigate the oxygen distribution, generated current, and minimum Pt loading of Pt/C electrode for practical applications based on kinetic model of oxygen reduction reaction. The results indicate that with increasing electrode effective thickness to 40 mm, serious concentration polarization is expected for Pt/C electrode. To generate a power density of 1.4 W⋅cm^-2 (2.1A⋅cm^-2@0.67 V) for fuel cell, the cathode catalyst layer thickness in PEMFC should be as thin as 3 mm. The minimum Pt loading will …

Synthesis Of Structurally Ordered Platinum-Iron Catalysts With Enhanced Oxygen Reduction Reaction Activity, Ye-Zheng Cai, Ming-Chuan Luo, Fang-Hui Wang, Zhao-Nan Sun, Hong Zhu

Journal of Electrochemistry

To improve oxygen reduction reaction catalytic activity of the precious metals platinum for fuel cell, the precursors of carbon-supported structurally disordered platinum-iron alloy (D-Pt₃Fe/C and D-PtFe/C) catalysts with different compositions were synthesized via a modified polyol reduction method. Then, by optimizing the annealing conditions in the inert gas, we turned the structurally disordered platinum-iron alloy to the structurally ordered platinum-iron alloy (O-Pt₃Fe/C and O-PtFe/C) catalysts. The structural characterizations of the as-prepared catalysts were performed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and X-ray photoelectron spectroscopy (XPS). The results …

Rambling Between "Zhong Yong" And "Catalysis", Zi-Dong Wei

Journal of Electrochemistry

“Zhong Yong” represents a traditional Chinese wisdom, which was first proposed by Confucius and continuously richened by his followers. “Zhong Yong” pursues the balances among all kinds of contradictions, and insists that neither “too much” nor “not enough” is good. For a successful catalyst, on which the adsorption of reactants must be not so strong and not so weak either. On this point of view, there are the same pursuits for “Zhong Yong” and catalysis. In this paper, the author starts his story with a conversation between Confucius and his student, followed by 3 interesting stories happening in the ancient …

Nitrogen, Fluorine Co-Doped Silk-Derived Carbon For Electrochemical Oxygen Reduction With High Performance In Alkaline Solution, Fang-Fang Liu, Hong-Liang Peng, Shi-Jun Liao

Journal of Electrochemistry

A high-performance, doped carbon-based catalyst was synthesized by pyrolyzing hydrothermally treated silkworm cocoon. The effects of preparation conditions and fluorine promotion on various catalysts’ performance were investigated. The catalyst prepared under optimal conditions and doped with nitrogen and fluorine possessed the high specific surface area of more than 1000 m^2⋅g^-1 and contained 3.5 and 7.3% (by mass, the same below) N and F, respectively. The activity of the catalyst toward oxygen reduction reaction in an alkaline medium was comparable to that of commercial Pt/C, showing both superior tolerance to methanol poisoning and better durability. Doping with fluorine …

Microwave-Assisted Synthesis Of Metal Oxides Nanoparticles : Efficient Heterogeneous Catalysts For Applications In Pollution Control Technologies, Hany A. Elazab Dr

Chemical Engineering

Metal oxides and Magnetic nanoparticles have been recognized as a class of nanostructured materials of current interest due to its well-known outstanding physical and chemical properties; especially when used in combination with other metal nano-particles. These kinds of nanostructured materials play an important role in many aspects of research ranging from catalysis and biology to material science, advanced technological, medical applications, and green chemistry. The metal oxide nano catalysts are also of great importance in improving the thermal-catalytic decomposition performance. The advanced and unique magnetic, electronic, and catalytic properties of the materials in the nano scale attracted research centers to …

Moving Horizon Estimation For An Industrial Gas Phase Polymerization Reactor, Jasmeer Ramhal, Kenneth V. Allsford, John Hedengren

Faculty Publications

A large-scale set of differential and algebraic equations (DAEs) is used to model and control an industrial gas phase polymerization reactor. Moving horizon estimation, preceding the nonlinear control optimization, provides an estimate of the current states and unmeasured disturbances. MHE is compared to Implicit Dynamic Feedback (IDF^TM)^*. With MHE, there is improved estimation of unmodeled disturbances in the UNIPOL^TM** polyethylene plant. The polymerization model is converted to algebraic equations by orthogonal collocation and solved with the MHE objective function in a simultaneous optimization. NOVA^TM, an active-set sparse NLP solver, is used to converge …

Antioxidant Potential Of Juglans Nigra, Black Walnut, Husks Extracted Using Supercritical Carbon Dioxide With An Ethanol Modifier, Johnathon Wenzel, Cheryl Storer Samaniego, Lihua Wang, Laron Burrows, Evan Tucker, Nathan Dwarshuis, Michelle Ammerman, Ali Zand

Chemical Engineering Publications

The black walnut, Junglas nigra, is indigenous to eastern North America, and abscission of its fruit occurs around October. The fruit consists of a husk, a hard shell, and kernel. The husk is commonly discarded in processing, though it contains phenolic compounds that exhibit antioxidant and antimicrobial properties. For this study, black walnut husks were extracted using supercritical carbon dioxide with an ethanol modifier. The effects of temperature, ethanol concentration, and drying of walnut husks prior to extraction upon antioxidant potential were evaluated using a factorial design of experiments. The solvent density was held constant at 0.75 g/mL. The optimal …

A Self-Sufficient Nitrate Groundwater Remediation System: Geobacter Sulfurreducens Microbial Fuel Cell Fed By Hydrogen From A Water Electrolyzer, Julie N. Renner

Faculty Scholarship

Nitrate contamination of groundwater is a major problem, especially in farming areas where nitrogen-based fertilizers are used. Geobacter sulfurreducens electrodes were electrochemically evaluated for their ability to reduce nitrate with implications for groundwater remediation. G. sulfurreducens were optimized for nitrate reduction by modifying growth media during subculture. The Geobacter were then cast on Toray carbon paper electrodes and immobilized with pectin. Cyclic voltammetry demonstrated that the electrodes bioelectrocatalytically reduce nitrate with an onset potential of −0.25 V vs. SCE. Amperometry was used to evaluate nitrate concentrations between 0.5 and 270 mM. The limit of detection is 8 mM with a …

Modeling Product Cooling For Baked And Snack Crackers, Jenna Hagenloch

Honors Theses

The cooling of snack crackers, after the baking process is an important step prior to packaging. A model was developed for cooling the crackers. The model allows for the adjustment of multiple operating conditions, such as temperature, depth of the crackers, and the speed of the line. The completed model provides the user with the ability to predict cooling requirements and to validate pre-existing equipment operating conditions. The model will aid in the design of new equipment as well as modifications to improve existing installations to operate within the desired specifications for each process.

Sustained Cell Differentiation Of 2d H9 Human Embryonic Stem Cells Into Mesenchymal Stem Cells, Hannah M. Christian

UCARE: Research Products

This experiment consisted of the controlled differentiation of H9 embryonic stem cells to mesenchymal stem cells. Though this experiment was repeated twice and improvement was seen in these repetitions, the cells were only able to be partially differentiated. However, the morphology of the differentiated cells is similar to those of healthy adult mesenchymal stem cells.

The progression of the differentiation can be seen in the microscope slide photos below. Throughout the differentiation, there occurred a decrease in cell survival and reduction of cell growth, but an increase in mesenchymal stem cell morphology. Throughout the last week of the differentiation, very …

Optimizing Chemical & Rheological Properties Of Rejuvenated Bitumen, Dominic Nguyen, Hamzeh Haghshenas Fatmehsari, Santosh Kommidi, Yong-Rak Kim

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Bitumen has long been a material used in the construction of roadways, yet new pavement only consists of low fractions of recycled materials due to poor compatibility of aged bitumen and new materials. Thus, rejuvenators, chemical additives, have been used in an attempt to re-balance the chemical composition and restore the physical properties of aged bitumen back to its virgin state. A fundamental understanding of how one particular rejuvenator, soybean oil, revitalizes bitumen was investigated using a multi-scale approach.

Fourier-transform infrared spectroscopy (FTIR) was used to determine the changes in chemical properties of pure and rejuvenated virgin and aged samples. …

Protein Synthesis Directly From Pcr: Progress And Applications Of Cell-Free Protein Synthesis With Linear Dna, Song-Min Schinn, Andrew Broadbent, William T. Bradley, Bradley Charles Bundy

Faculty Publications

A rapid, versatile method of protein expression and screening can greatly facilitate the future development of therapeutic biologics, proteomic drug targets and biocatalysts. An attractive candidate is cell-free protein synthesis (CFPS), a cell-lysate-based in vitro expression system, which can utilize linear DNA as expression templates, bypassing time-consuming cloning steps of plasmid-based methods. Traditionally, such linear DNA expression templates (LET) have been vulnerable to degradation by nucleases present in the cell lysate, leading to lower yields. This challenge has been significantly addressed in the recent past, propelling LET-based CFPS as a useful tool for studying, screening and engineering proteins in a …

Effect Of Packaging Material On Color Properties Of Catsup Tomato Sauce, Naser Kohan-Nia, Babak Pakbin, Razzagh Mahmoudi, Omid Fakhri

Journal of Applied Packaging Research

Catsup and tomato sauce products currently are one of the most popular and commercially available table sauces particularly consumed by young people and families around the world in recent decades. In this study colorimetric properties of catsup sauce samples including L*, a* and b* values in different packaging materials including PP, PE, PET, Glass and Sachet have been investigated during and after 180 days storage time at 22̊ C (environmental temperature). Hunter Lab system has been used to evaluate the color values of sauce samples. According to obtained results of experimental measurements and sensory evaluations, PP and PE packaging materials …

Immobilization Of Cellulase For Large Scale Reactors To Reduce Cellulosic Ethanol Cost, Dezhi Zhang

Doctoral Dissertations

Cellulosic ethanol is an alternative renewable energy source. Cellulase used in the production of cellulosic ethanol is very expensive. The difficulty in separating cellulase from the cellulose solution after the hydrolysis process limits the reusability of the cellulase, which highly precludes the scales of this application because of the high cost of the enzyme. Immobilization of cellulase provides a promising approach to allow the enzyme to be recycled, thus reducing the production cost. This research focused on immobilizing cellulase for reuse to reduce the cellulosic ethanol cost.

Four immobilization techniques were explored for the immobilization of cellulase on four different …

Manufacturing Polyacrylonitrile Nanowires And Nanofibers For Sensing And Energy Storage Applications, Juan Chen

Doctoral Dissertations

A novel flow guided assembly approach is presented to well align and accurately position nanowire arrays in pre-defined locations with high throughput and large scale manufacturing capability. In this approach, polyacrylonitrile (PAN)/N, N-dimethylformamide (DMF) solution is first filled in an array of microfluidic channels. Then a gas flow is introduced to blow out most solutions while pushing a little leftover against the channel wall to assemble into polymer nanowires. In this way, highly-ordered nanowires are conveniently aligned in the flow direction and patterned along both sides of the microchannels. In this study, we demonstrated this flow-guided assembly process by producing …

Thermal Properties, Crystallinity, And Oxygen Permeability Of Na-Montmorillonite Reinforced Plasticized Poly(Lactic Acid) Film, Kurniawan Yuniarto, Yohanes Aris Purwanto, Setyo Purwanto, Bruce A. Welt, Hadi Karia Purwadaria, Titi Candra Sunarti

Makara Journal of Technology

Introducing unmodified organically clay/Na-montmorillonite (Na-MMT) was applied into plasticized poly(lactic acid) PLA to produce film composites by direct casting. Film composite structure, the crystallinity degree and form, and thermal properties were carried out using X-ray diffraction and differential scanning calorimetry. The effect of Na- MMT to the tortuous path and the crystallinity degree in the plasticized film composites were calculated in oxygen barrier properties. Chromatogram film composites resulted in an intercalated structure that showed peak diffraction angle shift at about 0.2o. Then, a peak diffraction pattern was indicated in α-form crystal structure. Plasticized PLA has a crystallinity degree at 34%, …

Residual Strength Analysisof Asymmetrically Damaged Ship Hull Girderusing Beam Finite Element Method, Muhammad Zubair Muis Alie

Makara Journal of Technology

The objective of the present study is to analyze the residual strength of asymmetrically damaged ship hull girder under longitudinal bending. Beam Finite Element Method is used for the assessment of the residual strength of two single hull bulk carriers (Ship B1 and Ship B4) and a three-cargo-hold model of a single-side Panamax Bulk Carrier in hogging and sagging conditions. The Smith’s method is adopted and implemented into Beam Finite Element Method. An efficient solution procedure is applied; i.e. by assuming the cross section remains plane, the vertical bending moment is applied to the cross section and three-cargo-hold model. As …

Discrete Power Control In Heterogenous Networks, Yuanyuan Wang, Wibowo Hardjawana, Branka Vucetic

Makara Journal of Technology

In heterogeneous networks (HetNets) where femtocell base stations (FBSs) are deployed within the radio coverage of macrocell base stations (MBSs) to increase network capacity, co-channel interference limits overall system performance with universal frequency reuse. This paper investigates new distributed downlink discrete power control scheme for FBSs in HetNets with FBSs cooperation. The objective of the proposed power control scheme is to maximize the number of simultaneous FBSs transmissions in a single transmission wireless channel where each FBS is allowed to transmit only if the signal-to-interference-noise ratio (SINR) requirements for both FBSs and MBS users are satisfied. We apply a stochastic …