Engineering Commons^™

Gold Thin Film Electrodes For High Sensitivity & Selectivity Electrochemical Detection Of Arsenite In Water, Tybur Q. Casuse Driovínto

Civil Engineering ETDs

This is partial fulfillment of a dissertation defense on electrochemical detection of Arsenic (As) in water using gold (Au) nanofilms as sensing electrodes. The maximum contaminant level of Arsenic in drinking water is set at 10 g L^-1 by the WHO and USEPA. Electrochemical detection by linear stripping voltammetry has comparable detection limits to more expensive laboratory-based methods but with added benefits of being portable and manufacturable. The work has developed sputtered and crystallographically oriented nanofilms for detection of trace As (III). Ultraflat Au(111) oriented thin films, Au(UTF), were compared to single crystal model electrodes to identify the impacts …

Hydrothermal Liquefaction (Htl) Of Lignocellulosic Biomass For Biocrude Production: Reaction Kinetics And Corrosion-Resistance Performance Of Candidate Alloys For Reactors, Haoyu Wang

Electronic Thesis and Dissertation Repository

In recent years, the rapid increase in the demand for clean energy and green chemicals as well as concerns over the supply and environmental impacts associated with fossil. resources have stimulated intensive research on conversion of bioresources, such as lignocellulosic biomass and biowaste, into energy, fuels, chemicals, and materials.

Hydrothermal liquefaction (HTL) is a unique thermochemical conversion process, particularly applicable for the conversion of wet biomass and biowaste feedstocks. Most of the biomass HTL studies are conducted in batch reactor and focus on the effects of catalysts, reaction temperature and time on production efficiency and chemical properties of the products. …

Exploring Methods For Recycling Filament Waste In 3d Printing, Max Rios Carballo

Publications and Research

The goal of the current study is to investigate cutting-edge techniques for recycling filament waste from 3D printing procedures. Appropriate waste management techniques are required to reduce this trash's harmful environmental consequences. The goal of the project is to look at new methods for recycling filament waste in order to minimize disposal and encourage reuse. To acquire data from pertinent papers and research, a thorough literature review methodology was used. The findings show that this issue may be resolved utilizing a variety of recycling techniques, including shredding, melting, and re-extrusion. The type of filament waste and the intended goal will …

Greenhouse Gas Emissions From Milk Production In The Us, Cailey Cooper

Chemical Engineering Undergraduate Honors Theses

Life cycle assessment is performed to determine the environmental impacts of the life cycle of a product. In this study, the greenhouse gas emissions from milk production in the United States were calculated using a cradle-to-gate analysis. The dairy industry has a noticeable impact on the total greenhouse gas emissions in the US. Performing life cycle assessment provides information about the main emission sources in the life cycle which can spark innovative changes to reduce these emissions. The life cycle assessment was performed using the openLCA software and ReCiPe impact assessment methodology. The results indicated that 1.28 kg of carbon …

Comparing Firocoxib And Meloxicam In The Application Of Microneedle Patch For Transdermal Drug Delivery, Ruohan Li

Chemical Engineering Undergraduate Honors Theses

This thesis compares the performance of meloxicam and firocoxib in the aspects of its physical characteristic, chemical compositions, and in-vitro performances for transdermal pain management microneedle patches on farm animals. The microneedle patches are composed of polyvinyl alcohol (PVA), type I collagen (COL), and chitosan (CHI) as base material that carries NSAIDs to achieve therapeutic purposes. Scanning electron microscopy (SEM) was utilized to observe the morphological and physical characteristics of the microneedle patches. Both meloxicam and firocoxib microneedle patches were successfully prepared using the methodology, with organized microneedle distribution and sizing. And Fourier transform infrared spectroscopy (FTIR) confirmed the chemical …

Novel Microdevices To Analyze Toxic Volatile Organic Compounds., Sujoy Halder

Electronic Theses and Dissertations

There has been a growing interest to measure volatile organic compounds (VOCs) in a range of environmental applications. The presence of toxic VOCs in the air has been associated with serious health problems including asthma, central nervous system dysfunction, cardiovascular disease and cancer, etc. Different analytical instruments such as gas chromatography-mass spectrometry (GC-MS) and sensor systems, such as metal oxide sensors are used to analyze VOCs. However, challenges still exist in the detection of airborne VOCs because of their trace concentration and interference with complex gas mixtures. In this dissertation, two microfabricated devices, a sensor array and a micropreconcentrator were …

Probing The Structure Of Water On Surfaces: From Water Absorption To Ice Nucleation, Jiarun Zhou

All Dissertations

Water, essential for all life forms, is the most abundant, simple, yet mysterious molecule in the world. This molecule, consisting of only three atoms, behaves in unexpectedly different ways with the change of environment. In the past, studies of water under different conditions (temperature, pressure, on the surfaces, with confinement) have been conducted using experimental and computational methods. However, the influence of a given environment on water properties is yet to be fully understood. This dissertation studies water at complex interfaces (surfaces with various chemistry and physics properties) in both the liquid and crystalline states. Various heterogeneous systems used to …

Detection Of Toxic Aldehydes In Aerosols Of Electronic Cigarettes., Ellie Bess Reed

Electronic Theses and Dissertations

Over the past decade, use of electronic cigarettes (e-cigarettes) has increased in the younger generations of the United States. With the broad range of flavors and devices distributed on the market, American youth are prime marketing targets for the e-cigarette industry. To create a more regulated market, research of this thesis has been conducted on newer generations of e-cigarette “MOD” devices to examine how e-cigarette battery power output and coil temperature, concentrations of propylene glycol and vegetable glycerin, added flavorings (strawberry, mango, and menthol), and the presence of nicotine affect generation of aerosol particles and aldehydes in aerosols emitted by …

Synthesis, Property Tuning And Degradation Studies Of Phosphorene-Based Materials., Usman Onuminya Abu

Electronic Theses and Dissertations

Two-dimensional (2D) layered materials have sparked the interest of researchers because of their interesting properties drawn from quantum confinement effects, elevated density of states (DOS), increased surface area, increased active sites, etc. Phosphorene, an interesting addition to the 2D material family in 2014, has interesting properties such as in-plane anisotropy, elevated carrier mobility and thickness-dependent bandgaps that have made it a material of intense interest. Furthermore, there have been theoretical studies predicting that phosphorene could be made even more versatile by intercalating alkali atoms into its layers. Intercalation has proven to be a veritable tool for synthesis, modification, transformation, and …

Adsorptive Properties And On-Demand Magnetic Response Of Lignin@Fe3o4 Nanoparticles At Castor Oil–Water Interfaces, Mohammad J. Hasan, Emily Westphal, Peng Chen, Abishek Saini, I-Wei Chu, Sarah J. Watzman, Esteban E. Ureña-Benavides, Erick S. Vasquez

Chemical and Materials Engineering Faculty Publications

Lignin@Fe3O4 nanoparticles adsorb at oil–water interfaces, form Pickering emulsions, induce on-demand magnetic responses to break emulsions, and can sequester oil from water. Lignin@Fe3O4 nanoparticles were prepared using a pH-induced precipitation method and were fully characterized. These were used to prepare Pickering emulsions with castor oil/Sudan red G dye and water at various oil/water volume ratios and nanoparticle concentrations. The stability and demulsification of the emulsions under different magnetic fields generated with permanent magnets (0–540 mT) were investigated using microscopy images and by visual inspection over time. The results showed that the Pickering emulsions were more stable at the castor oil/water …

Preparation, Cure, And Characterization Of Cyanate Ester-Epoxy Blends Containing Reactive Flame Retardants, Mustafa Mukhtar, Donald A. Klosterman

Chemical and Materials Engineering Faculty Publications

Cyanate ester resins are sometimes mixed with lower cost epoxy monomers to modify cost, toughness, and processing capabilities. Despite the high performance of these thermosetting polymers, flame retardancy remains an issue. This study examined blends of three different commercial cyanate ester monomers (LVT-100, LECy, and XU-71787.02) and diglycidyl ether of bisphenol A (DGEBA) at 50/50 wt% of each type. The blends were successfully reacted with two reactive flame retardants (FR): 9,10-dihydro-9-ox-9-phosphaphenanthrene-10-oxide (DOPO) and poly(m-phenylene methylphosphonate) (PMP) at phosphorus contents ranging from 0 to 3 wt%. The curing behavior of EP/CE blends was investigated using differential scanning calorimetry (DSC). It was …

Utilizing Computer-Aided Molecular Design With Azido-Ester Plasticizers, Justin Ebert

Williams Honors College, Honors Research Projects

The goal of this project was to utilize Computer-Aided Molecular Design (CAMD) using the Signature molecular descriptor to inversely design optimized azido-ester plasticizers. Azido-ester plasticizers are used to modify the mechanical properties of propellant and explosive formulations. With the assistance of quantitative structure-property relationships, QSPRs, and two types of constraint equations, these new, novel plasticizers have the potential to possess optimal physical and chemical properties. Properties investigated in this work were decomposition temperature, heat of formation, glass transition temperature, and molecular weight. These properties were chosen for their importance when formulating propellants or explosives. After the filters were applied to …

Distillery, Clare Nicholas, Patrick Hanlon

Williams Honors College, Honors Research Projects

The goal for this project is to make a cost effective still. We will be implementing cost saving parts to create a cheap but effective still. From initial research conducted, we will try to combine a stainless steel still and copper still together so that the cheaper material (stainless steel) and the component that removes sulfur compounds (copper) are both implemented. The ME side of the project will focus on the actual design and construction of the parts that will be implemented into the still. Included in the design process will be calculations of heat transfer for the current and …

Synthesis Of Quasi-Freestanding Graphene Films Using Radical Species Formed In Cold Plasmas, Michael A. Mathews Jr.

Graduate Theses, Dissertations, and Problem Reports

For over a decade, the Stinespring laboratory has investigated scalable, plasma assisted synthesis (PAS) methods for the growth of graphene films on silicon carbide (SiC). These typically utilized CF₄-based inductively coupled plasma (ICP) with reactive ion etching (RIE) to selectively etch silicon from the SiC lattice. This yielded a halogenated carbon-rich surface layer which was then annealed to produce the graphene layers. The thickness of the films was controlled by the plasma parameters, and overall, the process was readily scalable to the diameter of the SiC wafer.

The PAS process reproducibly yielded two- to three-layer thick graphene films …

Mechanisms Of Emulsion Destabilization: An Investigation Of Surfactant, Stabilizer, And Detergent Based Formulations Using Diffusing Wave Spectroscopy, Jordan N. Nowaczyk

Theses and Dissertations

Conventional approaches for studying emulsions, such as microscopy and macroscopic phase tracking, present challenges when it comes to establishing detailed mechanistic descriptions of the impact of emulsifier and stabilizer additives. Additionally, while a combination of sizing methods and macroscopic phase tracking can provide insights into droplet size changes and concentration, the use of multiple measurements can be cumbersome and error-prone. It is the focus of this work, to present a new method for studying water in oil (W/O) emulsions that involves using diffusing wave spectroscopy (DWS) to examine the impact of three different surface stabilizing additives at varying concentrations. By …

Hygroscopic Tandem Differential Mobility Analyzer (Htdma) Design And Testing For Aerosol Hygroscopic Behavior Studies, Ziheng Zeng

Honors Theses

Most particles in the atmosphere take up water when exposed to increasing relative humidity (RH), and this behavior is described and quantized by a hygroscopicity parameter, kappa. Hygroscopic Tandem Differential Mobility Analysis (HTDMA) can be used to measure the physicochemical properties of aerosol particles and study phenomena that lead to size changes in submicron aerosol particles. Specifically, HTDMA measures how aerosol particles of different initial dry sizes grow or shrink when exposed to changing RH. HTDMA uses two differential mobility analyzers (DMAs) and a humidification system to make these measurements. One DMA selects a narrow size range of dry aerosol …

Hydro Cyclonic Separation Of Polyester Microfibers From Washing Machine Wastewater, Joe Kulkarni

Dissertations, Master's Theses and Master's Reports

Clothing made from synthetic materials shed fibers in washing machines, and these fibers find their way into the effluent water. These fibers can absorb toxic materials in wastewater treatment plants and can then carry these toxins into other aquatic environments.

It’s believed that a hydro cyclone could be scaled down enough to fit into a washing machine and could be used to filter out up to 80% of the microparticles from the effluent water. It’s proposed to investigate if a hydro cyclone can be used for this application. The overall goal was for the hydro cyclone to concentrate the micro …

Model Based Systems Engineering Approaches To Chemicals And Materials Manufacturing, Quang Le

Theses and Dissertations

Model-based systems engineering (MBSE) is part of a long-term trend toward model-centric approaches adopted by many engineering disciplines. This work establishes the need for an MBSE approach by reviewing the importance, complexity, and vulnerability of the U.S. chemical supply chains. The origins, work processes, modeling approaches, and supporting tools of the systems engineering discipline (SE) are discussed, along with the limitations of the current Process Systems Engineering (PSE) framework. The case is made for MBSE as a more generalizable and robust approach. Systems modeling strategies for MBSE are introduced, as well as a novel MBSE method that supports the automation …

Dynamic Modeling, Data Reconciliation, Parameter Estimation, And Health Monitoring Of A Supercritical Power Plant, Katherine Grace Hedrick

Graduate Theses, Dissertations, and Problem Reports

With the introduction of a larger portion of renewable sources of power coming onto the U.S. power grid in recent decades, the operational strategy of coal-fired power plants has changed significantly to focus more on flexibility in response to the changing energy market. This has naturally led to different operational challenges. Many of these challenges are focused on the boilers within these plants, as they are producing more emissions and experiencing increased damage during load-following, which in turn leads to increased costs from penalties for not achieving emission standards or maintenance costs as boilers accumulate damage from the cycling behavior. …

Microwave-Assisted Ammonia Synthesis Over Cs-Ru/Ceo2 Catalyst, Alazar Kesete Araia

Graduate Theses, Dissertations, and Problem Reports

Ammonia synthesis is one of the greatest innovations of the 20^th century with extensive applications from fertilizers to intermediates for nitrogen-containing chemicals and pharmaceuticals. Annually, more than 242 million tons of ammonia is produced globally, supporting approximately 27% of the world’s population. One of the fast-growing applications for ammonia is as H₂ energy carrier due to its high energy storage capacity, considered to be a decarbonized energy source. The low volumetric energy density and incompressibility makes Hydrogen a non-preferable energy carrier; an alternative carrier becomes a requirement. Ammonia possesses unique property as an energy-dense carrier to store and …

Phosphorus Release And Recovery From Simulated Ferric Wastewater Sludge, Aseel Alnimer

Theses and Dissertations (Comprehensive)

Phosphorus (P) is a fundamental element necessary for all life forms and a key component in the fertilizer industry. Meanwhile, the excessive load of P to water bodies due to human activities has the potential to promote eutrophication. Wastewater treatment plants remove P either biologically or chemically and produce P rich sludge which could be a potential renewable source for P. At present, commercial technologies exist for P recovery from biological wastewater sludge. However, P recovery from chemical sludge particularly iron(III)-phosphate (Fe-P) sludge generated in chemical P removal plants that use iron(III) salts remains a challenge.

This study explored, in …

Utilization Of Biopertalite For Fuel Efficiency And Reduction In Co And Co2 Gas Emissions In Four-Wheel Motor Vehicles, Ridwan Iskandar, Hadiyanto Hadiyanto, Suherman Suherman, Zainul Akmar Zakaria

Makara Journal of Technology

Emissions of carbon monoxide (CO) and carbon dioxide (CO2) gases are the main problem that must be rectified as they are harmful and contribute to global warming through the greenhouse gas effect. In Indonesia, motor vehicles, especially four wheelers, are one of the biggest contributors with up to 71 million tons of CO2 emissions and energy consumption of 179 million barrel of oil equivalent. Bioethanol has octane rating >100, which is higher than that of gasoline; and emission contribution of only 0.02 kg/L, which is lower than that from gasoline (2.23 kg/L). Accordingly, a mixture of gasoline and bioethanol is …

Multi-Criteria Decision Matrix Method In The Risk Analysis Of Biodiesel Production Processes, Kaylee Alles

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Renewable fuel technologies aim to mitigate the non-renewability of fossil fuels, challenges with increased energy demand, and the climate impact of fossil fuel emissions. However, before investing in renewable technologies, there need to be decision strategies that assess and identify the best alternatives according to stakeholder priorities. There is also a concern about whether the technologies that are the “most sustainable” effectively meet the acceptable risk requirements of stakeholders. In response to this question, a risk-adapted multi-criteria decision model was developed and compared to a sustainability study that evaluated five renewable diesel technologies, including Green Diesel I, II, and III; …

Anion Alloying Of Iii-V Semiconductors For Water Splitting., Sonia Calero-Barney

Electronic Theses and Dissertations

The challenge of solar energy conversion and storage translates into the discovery and development of semiconductor materials that can transform sunlight energy into electricity and/or high-energy-density fuels in a cost-effective way. From the solar energy conversion perspective, cation-alloyed III-V solar cells hold record-breaking energy conversion efficiencies, while anion-alloyed III-V’s are particularly interesting for photoelectrochemical hydrogen generation. The major challenge for the adoption of III-V-based technologies lies in the high manufacturing costs of established synthesis techniques and the difficulty to control the composition of ternary alloys. One of the materials investigated in this work is GaSb_zP_1-z. Thermodynamic …

Production Of Cellulose-Based Superabsorbent Polymers For Soil Water Retention, Rosa Maria Arredondo Ramirez

Electronic Thesis and Dissertation Repository

Superabsorbent polymers (SAPs) have attracted tremendous attention, with researchers noting that their high water absorption capacity (AC) is valuable for various applications, especially in agricultural contexts. Two types of materials can be used to produce SAPs: fossil-based (which are harmful to the environment) and bio-based (which are significantly more environmentally friendly, given their biodegradability and minimal toxic side effects). Although bio-based SAPs (Bio-SAPs) are preferable due to their environmental merits, their preparation tends to be time consuming and labour intensive, and their AC is still far below expectations. To address these problems, a novel, eco-friendly, cellulose-based superabsorbent polymer (Cellulo-SAP) was …

Synthesis Of A Phosphorus-Based Epoxy Reactive Flame Retardant Analog To Diglycidyl Ether Of Bisphenol A (Dgeba) And Its Behavior As A Matrix In A Carbon Fiber Composite, Mustafa Mukhtar

Chemical and Materials Engineering Faculty Publications

This paper describes the synthesis of a phosphorus-based flame retardant that is a chemical analog of diglycidyl ether of bisphenol A (DGEBA), as well as its incorporation as a matrix into carbon fiber laminates. Carbon fiber composites, if used for structural applications in mass transport vehicles (aircraft, trains), will require some aspects of improved fire performance to be used safely in those applications. The first phase of work involved the development of two separate synthesis routes to produce the flame retardant monomer, referred to as Phosphorus-DGEBA or simply P-DGEBA. The second step was to determine the viability of the compound's …

Highly Efficient De-Lignification And Reengineering Approach To Modify Wood Into A Bio-Composite And An Adsorbent Material, Ramon Filipe Beims

Electronic Thesis and Dissertation Repository

In this doctoral study, high-value bio-based materials, including a light-weight and high-strength wood-based composite material and a bio-based adsorbent material for removal of heavy metals in water, were developed from natural wood by a novel reengineering approach. In this approach, natural wood was first fractionated into a porous de-lignified wood and lignin. The porous de-lignified wood was then composited by impregnation of an epoxy resin synthesized with the lignin extracted from wood.

The wood-based composite preparation consisted of three main steps: (i) de-lignification of natural wood, (ii) lignin modification and epoxidation, and (iii) impregnation of the de-lignified wood with lignin-based …

Identification Of Lithocholic Acid As A Molecular Glass Host For Room-Temperature Phosphorescent Materials, John J. Flynn, Zachary M. Marsh, Douglas M. Krein, Steven M. Wolf, Joy E. Haley, Erick S. Vasquez, Thomas M. Cooper, Nicholas P. Godman, Tod A. Grusenmeyer

Chemical and Materials Engineering Faculty Publications

Lithocholic acid was identified as a molecular glass host material for room temperature phosphorescent (RTP) chromophores. Differential scanning calorimetry (DSC) was performed on a series of structurally similar, biologically sourced molecules, including lithocholic acid, β-estradiol, cholesterol, and β-sitosterol, in an effort to identify new amorphous molecular glasses independent of plasticizing additives. DSC analysis revealed lithocholic acid and β-estradiol form stable molecular glasses post thermal processing unlike neat cholesterol and β-sitosterol. The ability of lithocholic acid and β-estradiol to stabilize high wt. % loadings of d10-pyrene and a mixture of d10-pyrene and an iridium chromophore, bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate iridium(III) (FIr6), was also investigated. …

Identification And Distribution Analysis Of The Mid-Phase In A Low-Velocity Gas-Solid Fluidized Bed, Zhenan Zhang

Electronic Thesis and Dissertation Repository

The intermediate phase in low-velocity gas-solid fluidized beds generally presents excellent gas-solid contact in the systems. However, no comprehensive understanding of this vital phase is available in the literature. Therefore, this study proposed a statistical method to identify this intermediate phase, named ‘mid-phase’ in this thesis, to interpret the system performance based on the analysis of solids holdup in a low-velocity gas-solid fluidized bed.

The distributions of the mid-phase are investigated along both radial and axial directions in consideration of different flow regimes. The result shows that the turbulent regime contains a higher amount of mid-phase and the spatial mid-phase …

Electric Field Driven Co-Assembly And Transport Of Colloids Using Active-Passive Interaction, Brishty Deb Choudhury

LSU Master's Theses

Over the past few decades, the out-of-equilibrium transport and assembly of colloidal particles have been drawing significant interest due to their myriad applications in biology, engineering, and physics. In the absence of any external force, micro and nanoparticles perform Brownian motion in dispersion and are termed as passive colloids. In contrast, active colloids are a class of particles where a net imbalance of fluid flow around their surface drives their net migration in space when subjected to an external electric field. While several studies have shown the ability to program the dynamics of active colloids using an external electric field, …