Chemical Engineering Commons^™

Understanding The Thermodynamics And Oral Absorption Potential Of Pharmaceutical Amorphous Solid Dispersions, Nico Setiawan

Theses and Dissertations--Pharmacy

Supersaturating drug delivery systems, such as amorphous solid dispersions (ASDs), have been used extensively to elevate the apparent solubility and oral bioavailability of poorly water-soluble drugs. However, despite the numerous examples of success in increasing solubility and oral bioavailability using ASDs, physical stability challenges remain as formulators seek to employ high drug loading for cost reduction and improved patient compliance. Therefore, stability in both the solid and solution state must be considered for ASDs to be successful. In the solid state, the drug must remain amorphous in the solid matrix throughout the shelf life of the product. Although excipients, such …

Evaluation And Prevention Of Spontaneous Combustion During Handling And Storage Of Coal, Amir E. Najarzadeh

Theses and Dissertations--Mining Engineering

Spontaneous combustion of coal has historically been a major problem for the coal industry, predominantly during storage and transportation. Various methods have been used in the laboratory for evaluating the propensity of different coal sources to self-heat. However, the heterogeneity of coal and the complexity of the system has resulted in inconsistencies and sometimes conflicting results as indicated by the findings reported in several publications.

The primary objective of the current study was to build a laboratory scale apparatus that simulates the condition of a coal stockpile to evaluate the events leading to spontaneous combustion and develop potential remedies. As …

Pressure-Driven Stabilization Of Capacitive Deionization, Landon S. Caudill

Theses and Dissertations--Mechanical and Aerospace Engineering

The effects of system pressure on the performance stability of flow-through capacitive deionization (CDI) cells was investigated. Initial data showed that the highly porous carbon electrodes possessed air/oxygen in the micropores, and the increased system pressure boosts the gases solubility in saline solution and carries them out of the cell in the effluent. Upon applying a potential difference to the electrodes, capacitive-based ion adsorption occurs in competition with faradaic reactions that consume oxygen. Through the addition of backpressure, the rate of degradation decreases, allowing the cell to maintain its salt adsorption capacity (SAC) longer. The removal of oxygen from the …

Characterization Of Rotary Bell Atomizers Through Image Analysis Techniques, Jacob E. Wilson

Theses and Dissertations--Mechanical and Aerospace Engineering

Three methods were developed to better understand and characterize the near-field dynamic processes of rotary bell atomization. The methods were developed with the goal of possible integration into industry to identify equipment changes through changes in the primary atomization of the bell. The first technique utilized high-speed imaging to capture qualitative ligament breakup and, in combination with a developed image processing technique and PIV software, was able to gain statistical size and velocity information about both ligaments and droplets in the image data. A second technique, using an Nd:YAG laser with an optical filter, was used to capture size statistics …

Intermittency Effects On The Universality Of Local Dissipation Scales In Turbulent Boundary Layer Flows With And Without Free-Stream Turbulence, Sabah Falih Habeeb Alhamdi

Theses and Dissertations--Mechanical and Aerospace Engineering

Measurements of the small-scale dissipation statistics of turbulent boundary layer flows with and without free-stream turbulence are reported for Re_τ ≈ 1000 (Re_θ ≈ 2000). The scaling of the dissipation scale distribution is examined in these two boundary conditions of external wall-bounded flow.

Results demonstrated that the local large-scale Reynolds number based on the measured longitudinal integral length-scale fails to properly normalize the dissipation scale distribution near the wall in these two free-stream conditions, due to the imperfect characterization of the upper bound of the inertial cascade by the integral length-scale. When a length-scale based on Townsend's …

NoX Formation In Light-Hydrocarbon, Premixed Flames, Robert T. Hughes

Theses and Dissertations--Mechanical and Aerospace Engineering

This study explores the reactions and related species of NO_x pollutants in methane flames in order to understand their production and consumption during the combustion process. To do this, several analytical simulations were run to explore the behavior of nitrogen species in the pre-flame, post- flame, and reaction layer regions. The results were then analyzed in order to identify all "steady-state" species in the flame as well as the determine all the unnecessary reactions and species that are not required to meet a defined accuracy. The reductions were then applied and proven to be viable.

Partial Oxidation Of Ethane To Acetic Acid Using A Metallic Pd Promoted Movnb Catalyst Supported On Titania, Sulaiman Al-Mayman, Abdulrhman S. Al-Awadi, Yousef S. Al-Zeghayer, Moustafa A. Soliman

Chemical Engineering

The partial oxidation of ethane to acetic acid on a multi-component Mo16V6.37Nb2.05Pdx oxide catalyst supported on Degussa P25 titania has been investigated. The catalyst was characterized using BET surface area, X ray diffractometer (XRD) and transmission electron microscopy (TEM). The reaction was carried out in a differential reactor in a temperature range of 200-275°C and at a total pressure of 200 psi. The addition of trace amounts of nano-palladium, either as palladium oxides or metallic palladium, enhanced ethane oxidation towards the formation of acetic acid with near-complete depletion of the ethylene intermediate from the reactor effluent. The introduction of nano-Pd …

Assembling Of Niox/Mwcnts-Gc Anodic Nanocatalyst For Water Electrolysis Applications, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Saher D. Khamis Eng

Chemical Engineering

Glassy carbon (GC) electrode is intended to be modified with nickel oxide (NiOx) and multiwalled carbon nanotubes (MWCNTs) in the anodic reaction of water electrolysis. NiOx deposition time is optimized and a 5 min was enough to attain the maximum activity. A further modification of the catalyst with MWCNTs could greatly enhance its stability during continuous electrolysis. As an outcome, an energy amount of 21.7 kWh/KgO2 is minimized. Several electrochemical and materials characterization setups will be utilized to test the catalyst activity and to know its geometry and structure.

Fabrication Of Cuox-Pd Nanocatalyst Supported On A Glassy Carbon Electrode For Enhanced Formic Acid Electro-Oxidation, Islam M. Al-Akraa Dr., Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

Formic acid (FA) electro-oxidation (FAO) was investigated at a binary catalyst composed of palladium nanoparticles (PdNPs) and copper oxide nanowires (CuOxNWs) and assembled onto a glassy carbon (GC) electrode. /e deposition sequence of PdNPs and CuOxNWs was properly adjusted in such a way that could improve the electrocatalytic activity and stability of the electrode toward FAO. Several techniques including cyclic voltammetry, chronoamperometry, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction were all combined to report the catalyst’s activity and to evaluate its morphology, composition, and structure. /e highest catalytic activity and stability were obtained at the CuOx/Pd/GC …

Performance Of Nanoporous Carbon Membrane For Hydrogen Recovery, Abdulrahman A. Al-Rabiah, Abdelhamid M. Ajbar, Moustafa A. Soliman, Omar Y. Abdelaziz

Chemical Engineering

The aim of this work is to study the performance of nanoporous carbon membrane for hydrogen recovery from off-gas streams. The study is based on a rigorous mathematical model which can predict the performance of nanoporous selective surface flow (SSF) carbon membrane. Basically, the developed model is based on two transport mechanisms: the dusty gas flow through porous media and the surface adsorption-diffusion. The model was employed to simulate the hydrogen recovery from off-gas stream using SSF carbon membrane at different operating conditions. The separation performance of hydrogen-hydrocarbon mixture by nanoporous carbon membrane was evaluated and described. A comparison between …

Spectrally-Selective Energy-Harvesting Solar Windows For Public Infrastructure Applications, Mikhail Vasiliev, Kamal Alameh, Mohammad Alam

Research outputs 2014 to 2021

A study of photovoltaic solar window technologies is reported and it focuses on their structural features, functional materials, system development, and suitability for use in practical field applications including public infrastructures and agricultural installations. Energy generation performance characteristics are summarized and compared to theory-limit predictions. Working examples of pilot-trial solar window-based installations are described. We also report on achieving electric power outputs of about 25 Wp/m2 from clear and transparent large-area glass-based solar windows.

Effects Of Co-Product Uses On Environmental And Economic Sustainability Of Hydrocarbon Biofuel From One- And Two-Step Pyrolysis Of Poplar, Daniel G. Kulas

Dissertations, Master's Theses and Master's Reports

This study investigated the environmental and economic sustainability of liquid hydrocarbon biofuel production via fast pyrolysis of poplar biomass through two pathways: a one-step pathway that converted poplar via fast pyrolysis only, and a twostep pathway that includes a torrefaction step prior to fast pyrolysis. Optimization of these fast pyrolysis-based biofuel processes were investigated through heat integration and alternative uses of the co-product biochar, which can be sold as an energy source to displace coal, soil amendment or processed into activated carbon. The impacts of optimization on the cost of hydrocarbon biofuel production as well as the environmental impacts were …

Reverse Insulator Dielectrophoresis: Utilizing Droplet Microenvironments For Discerning Molecular Expressions On Cell Surfaces, Jeana Collins

Dissertations, Master's Theses and Master's Reports

Lab-on-a-chip (LOC) technologies enable the development of portable analysis devices that use small sample and reagent volumes, allow for multiple unit operations, and couple with detectors to achieve high resolution and sensitivity, while having small footprints, low cost, short analysis times, and portability. Droplet microfluidics is a subset of LOCs with the unique benefit of enabling parallel analysis since each droplet can be utilized as an isolated microenvironment. This work explored adaptation of droplet microfluidics into a unique, previously unexplored application where the water/oil interface was harnessed to bend electric field lines within individual droplets for insulator dielectrophoretic (iDEP) characterizations. …

Investigation Of Mechanical, Electrical, And Thermal Properties Of Particulate/Fiber/Polymer Composites, Julie Tomasi

Dissertations, Master's Theses and Master's Reports

Composites have many applications due to their high strength to weight ratio, chemical resistance, and the ability to tune properties like electrical resistivity (ER). In this work, polyetheretherketone (PEEK) and cycloaliphatic epoxy (CE) composites with different fillers were studied. PEEK composites contained up to 10 wt% Akzo Nobel Ketjenblack carbon black (CB), up to 15 wt% Asbury Carbons TC307 graphene nanoplatelets (GNP), up to 30 wt% Solvay carbon fiber (CF), and combinations of the three carbons. Formulations were developed for electrostatic dissipative and electrically conductive applications. The most conductive formulation was 7.5 wt% CB/30 wt% CF/PEEK, which had an electrical …

Molecular Biogeochemistry Of A Poor Fen, Zhimin Song

Dissertations, Master's Theses and Master's Reports

Variations in climate may rapidly change the carbon balance of peatlands and increase greenhouse gas emissions through accelerated decomposition of peat and dissolved organic matter (DOM). In this study, porewater samples were collected monthly from May to October in 2017 to study the effects of plant functional groups (PFGs) on DOM, dissolved inorganic and organic nitrogen through the season in a poor fen with replicate plots dominated by different PFGs in Nestoria, Michigan, USA (46.34˚N 88.16˚W). The composition of the peat porewater showed strong statistical significance with plot type and season.The observed PFG and season impact on the composition of …

Sequence Effects On The Glass Transition Temperature, William Drayer

Williams Honors College, Honors Research Projects

Lithium ion batteries are widely used for the energy needs of portable electronic devices. Unfortunately, current liquid organic solvents used as the electrolytic portion of the battery have low thermal stability, resulting in batteries that may combust upon failure. This flammability can be attributed to the configurational strain in cyclic organic electrolytes. Due to the lack of configurational strain in a flexible polymer chain, designing polymer electrolytes for use in lithium ion batteries may result in a safer battery due to their lower flammability in comparison to traditional liquid organic electrolytes. From the perspective of an electrolytic polymer, lowering the …

Fundamental Aspects Of A Novel Technology For Abatement Of Indoor Allergens, Odell Lendor Glenn Jr.

Theses and Dissertations

The overall goal of this research was to develop a novel approach to reduce the potency of certain asthma triggers, namely, proteins produced by pests or pets in indoor environments. The broad hypothesis of the research was that naturally occurring essential oils will demonstrate enhanced denaturing ability. In any indoor environment, allergens are bound to dry dust particles. In this work, the effectiveness of using dry ice and CO2 with potential for essential oils on dry allergenic proteins through CFD modeling and ELISA methods were evaluated.

There are three objectives central to this work. The first objective was to apply …

Surface And Structural Modification Of Carbon Electrodes For Electroanalysis And Electrochemical Conversion, Yan Zhang

Theses and Dissertations--Chemistry

Electrocatalysis is key to both sensitive electrochemical sensing and efficient electrochemical energy conversion. Despite high catalytic activity, traditional metal catalysts have poor stability, low selectivity, and high cost. Metal-free, carbon-based materials are emerging as alternatives to metal-based catalysts because of their attractive features including natural abundance, environmental friendliness, high electrical conductivity, and large surface area. Altering surface functionalities and heteroatom doping are effective ways to promote catalytic performance of carbon-based catalysts. The first chapter of this dissertation focuses on developing electrode modification methods for electrochemical sensing of biomolecules. After electrochemical pretreatment, glassy carbon demonstrates impressive figures-of-merit in detecting small, redox-active …

Influence Of Substrate Stage Temperature And Rotation Rate On The Magneto-Optical Quality Of Rf-Sputtered Bi2.1dy0.9fe3.9ga1.1o12 Garnet Thin Films, Mohammad E. Alam, Mikhail Vasiliev, Kamal Alameh

Research outputs 2014 to 2021

Highly bismuth-substituted iron garnet thin films are prepared on quartz substrates by using a radio frequency (RF) magnetron sputtering technique. We study the factors (process parameters associated with the RF magnetron sputter deposition technique) affecting the magneto-optical (MO) properties of ferrite garnet films of composition Bi2.1Dy0.9Fe3.9Ga1.1O12. All films show high MO response across the visible range of wavelengths after being annealed. In particular, the effects of substrate stage temperature and rotation rate on the various properties of films are studied. Experimental results reveal that the characteristics of garnet films of this type can be tuned and optimized for use in …

Ultrafast Consolidation Of Bulk Nanocrystalline Titanium Alloy Through Ultrasonic Vibration, Peng Chen, W. B. Liao, Lehua Liu, F Luo, Xiaoyu Wu, Peijie Li, C Yang, M Yan, Y. J. Liu, Laichang Zhang, Zhiyuan Liu

Research outputs 2014 to 2021

Nanocrystalline (NC) materials have fascinating physical and chemical properties, thereby they exhibit great prospects in academic and industrial fields. Highly efficient approaches for fabricating bulk NC materials have been pursued extensively over past decades. However, the instability of nanograin, which is sensitive to processing parameters (such as temperature and time), is always a challenging issue to be solved and remains to date. Herein, we report an ultrafast nanostructuring strategy, namely ultrasonic vibration consolidation (UVC). The strategy utilizes internal friction heat, generated from mutually rubbing between Ti-based metallic glass powders, to heat the glassy alloy rapidly through its supercooled liquid regime, …