Chemical Engineering Commons^™

Preparation And Properties Of Titanium Based Metal Oxide Electrodes For Ammonia Nitrogen Wastewater Treatment, Xue Li, Meng Xue, Ling Huang, Jun-Tao Li, Shi-Gang Sun

Journal of Electrochemistry

In this paper, four types of titanium based metal oxides electrodes were prepared by thermal decomposition method: Ti/SnO₂+Sb₂O₃, Ti/SnO₂+Sb₂O₃/SnO₂+IrO₂, Ti/SnO₂+Sb₂O₃/SnO₂+RuO₂, Ti/SnO₂+Sb₂O₃/SnO₂+CeO₂. The XRD results show that CeO₂ in Ti/SnO₂+Sb₂O₃/SnO₂+CeO₂ displayed a good crystal structure, and there was no significant oxygen evolution reaction occurred after electrolytic oxidation. Compared with the other three electrodes, the Ce-doped …

Naio4 Oxidation Of Mussel Adhesive Protein Film And Its Corrosion Protection For Mg-1.0ca Alloy, Rui-Qing Hou, Ping-Li Jiang, Shi-Gang Dong, Chang-Jian Lin

Journal of Electrochemistry

The effect of oxidation of mussel adhesive protein (Mefp-1) film on the corrosive resistance for Mg-1.0Ca alloy was investigated by scanning electron microscopy (SEM), atom force microscopy (AFM), electron probe microanalysis (EPMA), Infrared reflection absorption spectroscopy (IRAS) and electrochemical methods. The results showed that the NaIO₄ induced oxidation of the pre-formed Mefp-1 film with porous morphology involved structural change of the DOPA group in the protein and resulted in a more uniform film with net-like morphology. The protein film without oxidation had an increasing resistance for the corrosion of Mg-1.0Ca alloy up to 7 days exposure. After oxidation, Epit …

Electrochemical Monitoring Of Cell Wall-Regulated Transient Extracellular Oxidative Burst From Single Plant Cells, Jun-Tao Liu, Yan-Ling Liu, Zhi Cheng, Shi-Jing Chen, Wei-Hua Huang

Journal of Electrochemistry

Oxidative burst by rapid, transient generation of reactive oxygen species (ROS) is a fundamental process for plant disease defense and signal transduction. ROS can be protective or toxic depending on their concentrations, and critical balance between ROS production and scavenging is regulated by complex and perfect mechanisms in plant cells. However, the process of rapid and transient ROS burst from plant cells and their regulatory mechanisms are far from being completely understood, owing to the methodological obstacles in real-time monitoring such a fast process. In this work, we showed the application of microelectrode electrochemistry with high spatiotemporal resolution to monitor …

Heterogeneous Catalyst Deactivation And Regeneration: A Review, Morris D. Argyle, Calvin H. Bartholomew

Faculty Publications

Deactivation of heterogeneous catalysts is a ubiquitous problem that causes loss of catalytic rate with time. This review on deactivation and regeneration of heterogeneous catalysts classifies deactivation by type (chemical, thermal, and mechanical) and by mechanism (poisoning, fouling, thermal degradation, vapor formation, vapor-solid and solid-solid reactions, and attrition/crushing). The key features and considerations for each of these deactivation types is reviewed in detail with reference to the latest literature reports in these areas. Two case studies on the deactivation mechanisms of catalysts used for cobalt Fischer-Tropsch and selective catalytic reduction are considered to provide additional depth in the topics of …

Identification And Quantification Of Gaseous Organic Compounds Emitted From Biomass Burning Using Two-Dimensional Gas Chromatography–Time-Of-Flight Mass Spectrometry, Lindsay E. Hatch, Wentai Luo, James F. Pankow, Robert J. Yokelson, Chelsea E. Stockwell, Kelley Barsanti

Civil and Environmental Engineering Faculty Publications and Presentations

The current understanding of secondary organic aerosol (SOA) formation within biomass burning (BB) plumes is limited by the incomplete identification and quantification of the non-methane organic compounds (NMOCs) emitted from such fires. Gaseous organic compounds were collected on sorbent cartridges during laboratory burns as part of the fourth Fire Lab at Missoula Experiment (FLAME- 4) and analyzed by two-dimensional gas chromatography– time-of-flight mass spectrometry (GC × GC–ToFMS). The sensitivity and resolving power of GC × GC–ToFMS allowed the acquisition of the most extensive data set of BB NMOCs to date, with measurements for 708 positively or tentatively identified compounds. Estimated …

Superheated Liquid And Supercritical Denatured Ethanol Extraction Of Antioxidants From Crimson Red Grape Stems, Johnathon Wenzel, Lihua Wang, Cheryl Samaniego, La'shyla Nelson, Korrine Ketchum, Michelle Ammerman, Ali Zand

Chemical Engineering Publications

Grapes are widely known for health benefits due to their antioxidant content. In wine production, grape stems are often discarded, though they has a higher content of antioxidants than the juice. The effectiveness of using an environmentally friendly solvent, ethanol, as a superheated liquid and supercritical fluid to extract antioxidant compounds from grape stems of organically grown Crimson Seedless grapes was evaluated. The Ferric Reducing Ability of Plasma (FRAP) assay and the Total Phenolic Content (TPC), or Folin-Ciocalteu assay, were used to quantify the antioxidant power of grape stem extracts. The extractions were performed at temperatures between 160°C and 300°C …

Ring-Opening Polymerization Of Ε-Caprolactone Initiated By Ganciclovir (Gcv) For The Preparation Of Gcv-Tagged Polymeric Micelles, Alicia J. Sawdon, Ching-An Peng

Michigan Tech Publications, Part 1

Ganciclovir (GCV) is a nucleoside analogue with antiviral activity against herpes viral infections, and the most widely used antiviral to treat cytomegalovirus infections. However, the low bioavailability and short half-life of GCV necessitate the development of a carrier for sustained delivery. In this study, guanosine-based GCV was used as the initiator directly in ring-opening polymerization of ε-caprolactone (ε-CL) to form hydrophobic GCV-poly(caprolactone) (GCV-PCL) which was then grafted with hydrophilic chitosan to form amphiphilic copolymers for the preparation of stable micellar nanoparticles. Successful synthesis of GCV-PCL and GCV-PCL-chitosan were verified by ¹H-NMR analysis. Self-assembled micellar nanoparticles were characterized by dynamic …

A Versatile Microparticle-Based Immunoaggregation Assay For Macromolecular Biomarker Detection And Quantification, Haiyan Wu, Yu Han, George G. Chase, Qiong Tang, Chen-Jung Lee, Bin Cao, Jiang Zhe, Gang Cheng

Mechanical Engineering Faculty Research

The rapid, sensitive and low-cost detection of macromolecular biomarkers is critical in clinical diagnostics, environmental monitoring, research, etc. Conventional assay methods usually require bulky, expensive and designated instruments and relative long assay time. For hospitals and laboratories that lack immediate access to analytical instruments, fast and low-cost assay methods for the detection of macromolecular biomarkers are urgently needed. In this work, we developed a versatile microparticle (MP)-based immunoaggregation method for the detection and quantification of macromolecular biomarkers. Antibodies (Abs) were firstly conjugated to MP through streptavidin-biotin interaction; the addition of macromolecular biomarkers caused the aggregation of Ab-MPs, which were subsequently …

Highly Efficient And Magnetically Recyclable Graphene-Supportedpd/Fe3o4 Nanoparticle Catalysts For Suzuki And Heck Cross-Coupling Reactions, Hany A. Elazab

Chemical Engineering

tHerein, we report a facile and efficient one-step method for the synthesis of highly active, Pd/Fe3O4nanoparticles supported on graphene nanosheets (Pd/Fe3O4/G) that exhibit excellent catalytic activityfor Suzuki and Heck coupling reactions and that can be magnetically separated from the reaction mix-ture and recycled multiple times without loss of catalytic activity. The synthesis approach is based on theMicrowave (MW)-assisted reduction of palladium and ferric nitrates in the presence of graphene oxide(GO) nanosheets using hydrazine hydrate as the reducing agent. The results provide a fundamental under-standing of the system variables by comparing the catalytic activity and recyclability of four differentcatalysts with different …

Impact Of Internals Size And Configuration On Bubble Dynamics In Bubble Columns For Alternative Clean Fuels Production, Moses Kagumba, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bubble Columns Have Been Used in a Wide Range of Applications in Industry Including the Production of Alternative Clean Fuels Via Fischer-Tropsch Synthesis and Liquid Phase Methanol Synthesis, among Others. the Effects of Dense Internals Encountered in Fischer-Tropsch Synthesis with Different Diameters and Covering the Same Cross-Sectional Area and Hence Configuration on Bubble Properties Are Lacking in the Open Literature. Therefore, the Focus of This Study is to Investigate the Effects of Dense Internals with Different Diameters and Covering the Same Cross-Sectional Area and Hence Configuration on the Bubble Dynamics Such as Local and overall Gas Holdup, Specific Interfacial Area, …

Process For The Preparation Of Sufentanil Base And Related Components, Brian Orr, Joseph P. Haar Jr., George H. Klemm, Keith Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The present disclosure generally related to an improved process for the preparation of various piperidine derivatives. More particularly, the present disclosure related to an improved process for preparing sufentanil base (1) and related compounds, which advantageously utilizes more cost effective and/or less hazardous reagents, including a dispersion comprising between about 50% and about 70% by weight (based on the total weight of the dispersion) of an alkali metal hydride, such as sodium hydride, as well as eliminates the need for expensive and/or time consuming purification techniques.

Cytotoxic Activity Of Triazole-Containing Alkyl Ss-D-Glucopyranosides On A Human T-Cell Leukemia Cell Line, Edward Davis Oldham, Larissa M. Nunes, Armando Varela-Ramirez, Stephen E. Rankin, Barbara L. Knutson, Renato J. Aguilera, Hans-Joachim Lehmler

Chemical and Materials Engineering Faculty Publications

BACKGROUND: Simple glycoside surfactants represent a class of chemicals that are produced from renewable raw materials. They are considered to be environmentally safe and, therefore, are increasingly used as pharmaceuticals, detergents, and personal care products. Although they display low to moderate toxicity in cells in culture, the underlying mechanisms of surfactant-mediated cytotoxicity are poorly investigated.

RESULTS: We synthesized a series of triazole-linked (fluoro)alkyl β-glucopyranosides using the copper-catalyzed azide-alkyne reaction, one of many popular "click" reactions that enable efficient preparation of structurally diverse compounds, and investigate the toxicity of this novel class of surfactant in the Jurkat cell line. Similar to …

Investigating The Solubility And Cytocompatibility Of Cao-Na2o-Sio2/Tio2 Bioactive Glasses, Anthony W. Wren, Aisling Coughlan, Courtney M. Smith, Sarah P. Hudson, Fathima R. Laffir, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study aims to investigate the solubility of a series of titanium (TiO₂)-containing bioactive glasses and their subsequent effect on cell viability. Five glasses were synthesized in the composition range SiO₂-Na₂O-CaO with 5 mol % of increments TiO₂ substituted for SiO₂. Glass solubility was investigated with respect to (1) exposed surface area, (2) particle size, (3) incubation time, and (4) compositional effects. Ion release profiles showed that sodium (Na⁺) presented high release rates after 1 day and were unchanged between 7 and 14 days. Calcium (Ca²⁺) release …

Energy Process Enabled By Cryogenic Carbon Capture, Mark Jensen

Theses and Dissertations

Global climate change concerns help shape current environmental regulations, which increasingly seek to reduce or capture CO2 emissions. Methods for capturing CO2 emissions from energy processes have been the focus of numerous studies to provide support for those seeking to reduce the environmental impact of their processes. This research has (1) simulated a baseline case of energy-storing cryogenic carbon capture for implementation on a 550 MWe coal fired power plant, (2) presented a novel cryogenic carbon capture process for removing CO2 from natural gas down to arbitrary levels, (3) presented a natural gas liquefaction process that has the ability to …

Computational Multiscale Modeling And Characterization Of Piezoresistivity In Fuzzy Fiber Reinforced Polymer Composites, Xiang Ren, Josh Burton, Gary D. Seidel, Khalid Lafdi

Chemical and Materials Engineering Faculty Publications

In this paper, the piezoresistive response (i.e. the change of resistance under the application of strain) of polymer composites reinforced by a novel material known as fuzzy fibers is characterized by using single tow piezoresistive fragmentation tests and modeled by using a 3D computational multiscale model based on the finite element analysis. In the characterization work, the fuzzy fiber tow is embedded in a dog-bone specimen infused by epoxy, with resistance and displacement measured simultaneously to obtain its piezoresistive response. An approximately linear and stable piezoresistive response is observed within the fuzzy fiber tow region yielding gauge factors on average …

Molecular Modeling Of Sigma 1 And Sigma 2 Receptor Ligands: Pharmacophore Development And Comparison Using Discotech And Bioactivity Prediction Comparison Of Ab Initio And Density Functional Comfa Studies For Spiro And Other Receptor Ligands, Lisa M. Kardos

Dissertations

The role of the biological receptor is currently being studied by researchers in medicine. Information about sigma receptors in particular can be gained by studying the ligands associated with each type, sigma 1 or sigma 2. Sigma 1 receptor ligands consist of drug candidates that often have psychiatric and neurological applications; sigma 2 receptor ligands consist of drug candidates that have been linked with cancer treatment among other applications.

Molecular modeling of biological receptor ligands often encompasses pharmacophore development and Comparative Molecular Field Analysis (CoMFA). Pharmacophore models are developed to understand the unique features such as binding groups that make …

Combustion Dynamics Of Metal Powders In Mixed Gas Flows, Amy Lee Corcoran

Theses

Predictive mechanisms for particle ignition and combustion rates are required in order to develop optimized propellant and energetic formulations using micron-sized metal powders, such as aluminum and magnesium. Most current descriptions are based on laboratory experiments performed in stationary or laminar combustion configurations using pure metals burned in single oxidizers. However, practical configurations take into account different metals, including alloys, that burn in various oxidizing environments and various flow conditions. Validity of the present descriptions for such environments has not been established. This experimental study is aimed to measure burn times for aluminum, magnesium, and mechanically alloyed Al-Mg particles burning …

Accidental Poison: Analysis Of 1,4-Butanediol In A Popular Children's Arts And Crafts Toy, Christopher R. Dockery, John H. Shugart, Jonathan D. Parker, William J. Lawson

Faculty Articles

A popular children's arts and crafts toy made international headlines when it was discovered that 1,4-butanediol had been substituted into some of its formulations. The chemical 1,4-butanediol rapidly converts to the date-rape drug g-hydroxybutyric acid (GHB) upon ingestion and resulted in the accidental poisoning of some children. In this experiment, students extract 1,4-butanediol from commercially available toy beads (or prepared simulations) using their knowledge of pharmaceutical chemistry, solubility, etc. Using case studies available in the literature, students develop a quantitative analysis experiment for 1,4-butanediol extracted from the toy beads and, through approximation, relate the extractable amount of 1,4-butanediol to dose-response …

Urban And Rural Msw Stream Characterization For Separate Collection Improvement, Simona Ciuta, Tiberiu Apostol, Valentin Rusu

Publications and Research

In the new legislation framework enacted by new member countries of the European Union (EU), the characterization of municipal solid waste (MSW) represents an important instrument for local governments and sanitation operators in setting and achieving targets for waste recycling and recovery. This paper presents the results of a study conducted in accordance with the Romanian methodology for domestic wastes characterization ROMECOM, aiming to provide a proper basis for developing clear and realistic forecasts in current municipal waste management, based on MSW composition and generation rate. The analyzed MSW came both from areas where the waste is collected in mixed …

Ion Trap Mass Analyzer Apparatus, Methods, And Systems Utilizing One Or More Multiple Potential Ion Guide (Mpig) Electrodes, Curtiss Hanson

Patents (University of Northern Iowa)

In one aspect of the invention, an ion trap mass analyzer includes a variable- or multi-potential type ion guide (MPIG) assembly which has been pre-configured to produce a parabolic-type potential field. Each MPIG electrode has a resistive coating of designed characteristics. In one example the coating varies in thickness long the length of an underlying uniform substrate. The MPIG assembly can be a single MPIG electrode or an array of a plurality of MPIG electrodes. An array can facilitate delocalization for improved performance. This chemical modification of a uniform underlying substrate promotes cheaper and flexible instruments. The modified MPIG electrodes …