Chemical Engineering Commons^™

Methodological Significance Of "Property-Activity Relationship" For Catalyst Studies, Jun-Tao Lu, Li Xiao, De-Li Wang, Yu-Bao Sun, Yan-Ge Suo, Lin Zhuang

Journal of Electrochemistry

Instead of attempting the structure-activity relationship (SAR), which is commonly regarded as the core problem for catalyst studies, this paper highlights the methodological significance of “property-activity relationship (PAR)”. The “property” here refers to an index （such as the adsorption energy of an intermediate） or a group of indexes reflecting the behavior of a catalyst which interacts with reactants or intermediates, and is a bridge between structure and activity. Because property is related to activity more directly than structure to activity, PAR should be simpler, less difficult and, therefore, more feasible to be accessed than SAR. Once the key property is …

The Electrocatalytic Performance Of Pd Catalysts Supported On Pvp Modified Mwcnts For Formic Acid Oxidation, Jing Zhang, Xiao Zhao, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

In this paper the MWCNTs were modified by Poly (N-vinyl-2-pyrrolidone) (PVP) to support Pd nanoparticles, which were used as the catalyst for formic acid electrooxidation. And the performance of Pd/PVP-MWCNTs catalysts was studied by electrochemical measurements. The observations from Fourier transforms infrared spectrometer (FTIR) and transmission electron microscopy (TEM) illustrated that the Pd nanoparticles with a small size and narrow size distribution were highly dispersed on PVP-MWCNT support. Therefore, the Pd/PVP-MWCNTs catalysts showed excellent catalytic activity for formic acid electrooxidation.

Synthesis Of Spherical Ni3S4 By Solvothermal Method As Supercapacitor Electrodes, Qing-Na Huan, Li-Fang Jiao, Qing-Hong Wang, Hong-Mei Du, Jia-Qin Yang, Wen-Xiu Peng, Yi-Jing Wang, Hua-Tang Yuan

Journal of Electrochemistry

The Ni₃S₄ microspheres have been synthesized via a facile solvothermal method. The crystal structure and surface morphology are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Microspherical Ni₃S₄ exhibits good electrochemical capacitance validated by electrochemical measurements. The specific capacities of 1120.6 F∙g^-1 at 0.5 A∙g^-1 and 433.4 F∙g^-1 at 4 A∙g^-1 with the capacitance retention of 89.37 % and 84.88 % were obtained after 1000 cycles, respectively. The electrochemical reaction is expected due to the transformation of Ni(OH)₂ and NiOOH based on the XRD, XPS and CV …

An Overview Of Electrode Materials In Microbial Fuel Cells, Su-Qin Ci, Na Wu, Zhen-Hai Wen, Jing-Hong Li

Journal of Electrochemistry

Microbial fuel cells (MFCs) are devices that can directly convert organic chemical energy into electrical energy with microbial as catalysts. MFCs are a promising bio-electrochemical system with the potential to degrade organic sewage and produce electricity. This article supplies a critical and comprehensive review for the electrode materials concerning about anode and cathode in MFCs, including the fabrications, functional modifications and surface constructions of electrode materials, as well as their applications in MFCs. Additionally, the existing problems of electrode materials in current MFCs have been demonstrated in order to provide the guideline for exploring the next-generation electrode materials for MFCs.

Multiple Molecule Effects On The Cooperativity Of Protein Folding Transitions In Simulations, Jacob I. Lewis, Devin J. Moss, Thomas A. Knotts Iv

Faculty Publications

Though molecular simulation of proteins has made notable contributions to the study of protein folding and kinetics, disagreement between simulation and experiment still exists. One of the criticisms levied against simulation is its failure to reproduce cooperative protein folding transitions. This weakness has been attributed to many factors such as a lack of polarizability and adequate capturing of solvent effects. This work, however, investigates how increasing the number of proteins simulated simultaneously can affect the cooperativity of folding transitions — a topic that has received little attention previously. Two proteins are studied in this work: phage T4 lysozyme (Protein Data …

Performance Characteristics Of Lithium Coin Cells For Use In Wireless Sensing Systems, Yin Zhang

Theses and Dissertations

Understanding the pulsed discharge behavior of low-rate lithium coin cells in wireless sensing systems is critical to prolong the operating life and/or reduce the size of battery-powered WSs. This dissertation presents the battery transient analysis for a sensor duty cycle, experimental studies for sustained pulse discharge cycling, and investigation on recharge strategies for a battery/power harvesting hybrid system for WSs. The transient behavior of the lithium coin cells during pulse discharge and subsequent relaxation was investigated with single-pulse experiments and theoretical analysis. The voltage response for a pulsed discharge had two parts: a region of rapid voltage change and a …

Clay Minerals For Nanocomposites And Biotechnology: Surface Modification, Dynamics And Responses To Stimuli, Hendrik Heinz

College of Polymer Science and Polymer Engineering

Clay minerals find a wide range of application in composites, paints, drilling liquids, cosmetics, and medicine. This article reviews chemical and physical properties of natural and organically modified clay minerals to understand the nanometre-scale structure, surface characteristics, and application in functional materials. The relation between fundamental properties and materials design is emphasized and illustrated by examples. The discussion comprises the following: an overview; surface structure and cation density; solubility and solubility reversal by surface modification; the degree of covalent and ionic bonding represented by atomic charges; the distribution of metal substitution sites; measurements and simulations of interfacial properties at the …

Determination Of Phase Equilibria And The Critical Point Using Two-Phase Molecular Dynamics Simulations With Monte Carlo Sampling, Sonal Patel

Theses and Dissertations

The two-phase MD technique employed in this work determines the liquid and vapor phase densities from a histogram of molecular densities within phase clusters in the simulation cell using a new Monte Carlo (MC) sampling method. These equilibrium densities are then fitted in conjunction with known critical-point scaling laws to obtain the critical temperature, and the critical density. This MC post-processing method was found to be more easily implemented in code, and it is efficient and easily applied to complex, structured molecules. This method has been successfully applied and benchmarked for a simple Lennard-Jones (LJ) fluid and a structured molecule, …

Chemical Potential Perturbation: A Method To Predict Chemical Potential Using Molecular Simulations, Stan G. Moore

Theses and Dissertations

A new method, called chemical potential perturbation (CPP), has been developed to predict the chemical potential as a function of composition in molecular simulations. The CPP method applies a spatially varying external potential to the simulation, causing the composition to depend upon position in the simulation cell. Following equilibration, the homogeneous chemical potential as a function of composition can be determined relative to some reference state after correcting for the effects of the inhomogeneity of the system. The CPP method allows one to predict chemical potential for a wide range of composition points using a single simulation and works for …

Developing And Assessing Leadership In Engineering Students, W. Vincent Wilding, Thomas A. Knotts, William G. Pitt, Morris D. Argyle

Faculty Publications

Developing and Assessing Leadership in Engineering Students W. Vincent Wilding, Thomas A. Knotts IV, William G. Pitt, and Morris D. Argyle Department of Chemical Engineering, Brigham Young University The Ira A. Fulton College of Engineering and Technology at Brigham Young University is focusing on five initiatives: Leadership, Innovation, Global Awareness, Character, Technical Excellence. Efforts in the realm of leadership include freshmen leadership seminars and a required sophomore course entitled Global Leadership in a Technological World. Departments within the college are expected to build on this foundation in the junior and senior years. The Chemical Engineering Department has developed an effective …

A New Assessment Method To Easily Identify Areas Needing Improvement In Course-Level Learning Outcomes, Thomas Knotts, W. Vincent Wilding, William G. Pitt, Morris D. Argyle

Faculty Publications

A New Assessment Method to Easily Identify Areas Needing Improvement Course‐level Learning Outcomes Thomas A. Knotts IV, W. Vincent Wilding, William G. Pitt, and Morris D. Argyle Department of Chemical Engineering, Brigham Young University Assessment of student proficiency in expected outcomes, whether on the course or program level, is an important aspect of curriculum development in engineering programs. The reasons for such assessment range from desires to improve student learning to fulfilling requirements of various accreditation bodies. But regardless of the reasons, the challenge is to develop suitable metrics which can clearly identify areas which need improvement. In order to …

Review Of Corrosion Aspects Of Compression Ignition Engine Parts Using Biodiesel Blends, B. Singh, John Korstad, Y. C. Sharma

College of Science and Engineering Faculty Research and Scholarship

This paper reviews the effects of corrosion on the engine parts that come in contact with a newly developed biodiesel fuel and its petrodiesel blend. Copper, aluminum, copper alloys (bronze), and elastomers caused significant levels of corrosiveness in biodiesel and biodiesel blend as opposed to low corrosion with petrodiesel. Specimens of stainless steel showed significant resistance to corrosion in biodiesel samples as compared to copper, aluminum, and copper alloys, but the level of corrosion was still higher than that in petrodiesel. Common methods adopted for measurement of corrosion include weight loss through static emersion tests, and electrochemical techniques by electrochemical …

Fiber Optic Monitoring Of Subsea Equipment, David Brower, John Hedengren, Cory Loegering, Alexis Brower, Karl Witherow, Karl Winter

Faculty Publications

Bass Lite deepwater field in the Gulf of Mexico, at water depths of approximately 2,050 m (6,750 feet), commenced operation in February 2008. Natural gas is produced from Bass Lite via a 90-km (56-mile) subsea tieback to the Devils Tower Spar. This project involved several innovations, one of which was the incorporation of a fiber optic sensing system that measures realtime temperature, pressure and strain along the pipeline length. This is a first of its kind innovation that is in actual operation.

Novel Platform Development Using An Assembly Of Carbon Nanotube, Nanogold And Immobilized Rna Capture Element Towards Rapid, Selective Sensing Of Bacteria, Elizabeth I. Maurer, Kristen K. Comfort, Saber M. Hussain, John J. Schlager, Sharmila M. Mukhopadhyay

Chemical and Materials Engineering Faculty Publications

This study examines the creation of a nano-featured biosensor platform designed for the rapid and selective detection of the bacterium Escherichia coli. The foundation of this sensor is carbon nanotubes decorated with gold nanoparticles that are modified with a specific, surface adherent ribonucleic acid (RNA) sequence element. The multi-step sensor assembly was accomplished by growing carbon nanotubes on a graphite substrate, the direct synthesis of gold nanoparticles on the nanotube surface, and the attachment of thiolated RNA to the bound nanoparticles.

The application of the compounded nanomaterials for sensor development has the distinct advantage of retaining the electrical behavior …

Using Student Ambassadors To Relay Themes From Changing The Conversation In Engineering First Year Seminars, Sarah Rzasa Zappe, Melissa Marshall, Enrique D. Gomez, Esther W. Gomez, Angela D. Lueking

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper describes the efforts at a large mid-Atlantic university to integrate themes from Changing the Conversation into First Year Seminars. Changing the Conversation, a 2008 book by the National Academy of Engineering, found that both male and female students were more attracted to messages describing engineering in terms relating to societal impact, such as the phrases, "Engineering makes a world of difference" and "Engineering is essential to our health, happiness, and safety." Although the research was conducted with younger students, the potential for using these themes in the undergraduate curricula could have the potential to impact persistence in engineering, …

Optimization Of Co2 Wag Processes In A Selected Carbonate Reservoir: Laboratory Study, Mohamed Elwy Abdalla Amin

Theses

Miscible gas flooding using carbon dioxide is currently investigated as a possible EOR process for a number of United Arab Emirates (UAE) reservoirs. The major factors affecting the implementation of CO₂ floods are the availability of CO₂ at economic prices and the net utilization ratio of CO₂ per barrel of additional oil recovered.Minimizing net utilization requires controlling the high mobility ratio which causes lower sweep. To control the mobility ratio, the Water-Alternating CO₂-gas (WAG) technique is proposed.

The objective of this work is to experimentally assess the recovery of oil with CO₂ injection in …

Nanoenergetic Composite Based On I2o5/Al For Biological Agent Defeat, Mkhitar Hobosyan, Alexander V. Kazanksy, Karen S. Martirosyan

Physics & Astronomy Faculty Publications

The risk of bioterrorism events involving the intentional airborne release of contagious agents has led to development of new approaches for bio agent defeat technologies both indoors and outdoors. This report describes nanoenergetic gas generators (NGG) system that exhibit long term stability and superior release of biocidal substances for destruction of pathogenic bacteria. The effect of iodine vaporization on destroying of Escherichia coli (E-coli, HB101 K-12 strain) by using expressing Green Fluorescent Protein (GFP) was investigated. HB101 K-12 has been genetically modified to prevent its growth unless grown on an enriched medium. To obtain quantitative data we used pGLO transformation …

Mobility Of A Semiflexible Chain Confined In A Nanochannel, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman

Faculty Publications

The classic results of de Gennes and Odijk describe the mobility of a semiflexible chain confined in a nanochannel only in the limits of very weak and very strong confinement, respectively. Using Monte Carlo sampling of the Kirkwood diffusivity with full hydrodynamic interactions, we show that the mobility of a semiflexible chain exhibits a broad plateau as a function of extension before transitioning to an Odijk regime, and that the width of the plateau depends on the anisotropy of the monomers. For the particular case of DNA in a high ionic strength buffer, which has highly anisotropic monomers, we predict …

Scalable Synthesis Of Palladium Nanoparticle Catalysts By Atomic Layer Deposition, Xinhua Liang, Lauren B. Lyon, Ying Bing Jiang, Alan W. Weimer

Chemical and Biochemical Engineering Faculty Research & Creative Works

Atomic layer deposition (ALD) was used to produce Pd/Al2O 3 catalysts using sequential exposures of Pd (II) hexafluoro acetylacetonate and formalin at 200 °C in a fluidized bed reactor. the ALD-prepared Pd/alumina catalysts were characterized by various methods including hydrogen chemisorption, XPS, and TEM, and compared with a commercially available 1 wt.% Pd/alumina catalyst, which was also characterized. the content of Pd on alumina support and the size of Pd nanoparticles can be controlled by the number of ALD-coating cycles and the dose time of the Pd precursor. One layer of organic component from the Pd precursor remained on the …

Investigation Of The Fracture Phenomena During The Milling Process Of Inorganic Particulates And Brittle Fracture Of Polymer Composites Using Fractal Theory, Zheng Qian

Dissertations

This dissertation investigates the applicability and usefulness of applying Fractal mathematics and to the fracture of brittle particulates in Fluid Energy Mill devices, and in particular quantifying the resulting power law particle size distributions, examining the Surface Fractal Dimension of milled particulates, and relating the Izod Impact Strength values of composites of polypropylene and Calcium carbonate particulates which are large un-milled, small milled, as well as small and produced by the simultaneous milling and coating with nano-silica to the Surface Fractal Dimension of the impact fracture surfaces.

First, the dissertation examines the behavior of un-coated and micron-sized wax pre-coated particulates …