Engineering Commons^™

Design Of Active Pharmaceutical Ingredients Solid States In Crystallization Processes, Weizhong Gong

Electronic Thesis and Dissertation Repository

Crystallization is an important technique to obtain solid-state drugs from solutions. Physicochemical properties of the active pharmaceutical ingredients (APIs) are determined by crystallization. More than half of the active pharmaceutical ingredients exhibit polymorphism, the phenomenon of chemical species showing more than one unit-cell structure in the solid state. Controlling polymorphism is one of the most important goals during pharmaceutical manufacturing. Nevertheless, the control of polymorphism is sometimes not enough to realize the targeted physicochemical properties. Suitable additives (coformers/salt formers) are explored to generate new multi-component solid phases of poorly soluble/bioavailable active pharmaceutical ingredients (APIs). The design of pharmaceutical cocrystals and …

The Effect Of Steam Explosion On Lipids Extraction From Microalgae And Derivation Of Pectin Films From Waste Culture, Shahil Chhiba

Electronic Thesis and Dissertation Repository

The objective of this study was to investigate the properties of sustainable replacements for plastics and diesel fuel, derived from microalgae (Chlorella vulgaris) subjected to steam explosion. During the process, oven temperatures of up to 500 °C were reached, with the experiments left for different times after reaching their maximum internal temperature. Lipids were extracted from algal cultures using a modified Folch method. The waste microalgae were combined with pectin and glycerol to form biodegradable films, and their solubilities and tensile strengths were measured. The highest yield was 124 mg lipids/g microalgae from 400 °C steam explosion for …

Investigation Of Foam Based Photobioreactor For The Cultivation Of Chlorella Vulgaris Cpcc 90, Anuradha Krishnan

Electronic Thesis and Dissertation Repository

Today, microalgae are cultured in large-scale systems such as open ponds and photobioreactors. Open pond systems, while not expensive, have disadvantages, including contamination and high water consumption, resulting in increased cost of harvesting and quick evaporation. Photobioreactors overcome some of the challenges of an open pond system. However, the reactor setup, operation, and microalgae harvesting are relatively more expensive when compared to conventional techniques. In this study, a novel foam-based photobioreactor system was applied to investigate both the cultivation and harvest of microalgae using different surfactant agents, i.e., rhamnolipids, Bovine Serum Albumin (BSA), saponin, and the commercial surfactant Pluronic f127 …

Experimental And Simulation Study Of Reactive Silver Ink Droplet Evaporation, Weipeng Zhang

Electronic Thesis and Dissertation Repository

The evaporation of particle-free silver ink droplets on heated substrates directly impacts the morphology of the resultant silver particles and films. In this thesis, COMSOL Multiphysics simulations of the solvent (water-ethylene glycol mixture) droplet evaporation process are used to explain the microflows, mass transfers, and heat distribution responsible for the experimental observations. The reactive ink incorporates fluoro-surfactant FS-31 and poly (acrylamide) (PAM) to suppress the coffee-ring effect that negatively impacts the electrical conductivity. Experiments show that the droplet evaporation process results in varied silver particle morphology, depending on the locations within the droplet, leading to uneven surfaces. Large particles (3 …

Corrosion Case Study On Pipeline, Kangze Ren

Corrosion Research

The Kashagan pipeline leaks were likely caused by sulfur stress corrosion cracking, a combined corrosion mechanism developed by the presence of high pressure, the high level of hydrogen sulfide(the main "ingredient" of sour gas), and poor metallurgical choice. Improper welding and poor metallurgical examination were blamed for causing the leaking issue. The purpose of the current review is to raise the alarm about the inappropriate corrosion management of Kashagan oil production and its societal and environmental consequences.

Conversion Of Biomass Derived Tar In A Catalytic Post-Gasification Process, Floria Rojas Chaves

Electronic Thesis and Dissertation Repository

The present MESc thesis reports the performance of a fluidizable CeO₂ promoted Ni/γ-Al₂O₃ catalyst to be used in a post-gasification process for tar removal. The catalysts developed were prepared using the incipient wetness technique and characterized chemically and physically, using the following techniques: N₂ Adsorption-Desorption, XRD, NH₃ and CO₂ TPD, Pyridine-FTIR, H₂-TPR, and H₂-Pulse Chemisorption. The catalysts were tested in a fluidized CREC Riser Simulator, in the 500°C-550°C temperature range, within 5 s-10 s reaction times, using both steam and steam-H₂/CO₂ atmospheres.A 2-methoxy-4-methlyphenol (2M4MP) compound was …

Engineering Multifunctional Adhesive Hydrogel Patches For Biomedical Applications, Aishik Chakraborty, Shana Alexander, Wei Luo, Narisse Al-Salam, Mia Van Oirschot, Sudhir H. Ranganath, Subrata Chakrabarti, Arghya Paul

Chemical and Biochemical Engineering Publications

Traditional patches, such as sticking plaster or acrylic adhesives used for over a hundred years, lack functionality. To address this issue of poor functionality, adhesive hydrogel patches have emerged as an efficient bioactive multifunctional alternative. Hydrogels are three-dimensional, water-swellable, and polymeric materials closely resembling the native tissue architecture. The physicochemical properties of hydrogels can be modified easily, allowing them to be suitable for various biomedical applications. Moreover, adhesive properties can be imparted to hydrogels through physicochemical manipulations, making them ideal candidates for supplementing or replacing traditional sticking plaster. As a result, sticky hydrogel patches are widely used for transdermal drug …

Application Of Crystal Engineering In Multicomponent Pharmaceutical Crystals: A Study Of Theory And Practice, Soroush Ahmadi Nasrabadi

Electronic Thesis and Dissertation Repository

Multicomponent crystallization, a prominent strategy in crystal engineering, offers the ability to modify the physicochemical properties of crystals by introducing a secondary component to their lattice structure. Such multicomponent crystals have found widespread application in the pharmaceutical industry. This thesis explores the experimental screening, characterization, application, and theoretical prediction of multicomponent crystals of Active Pharmaceutical Ingredients (APIs).

The first case study investigates a new solvate of Dasatinib which exhibits high instability at room temperature and transforms into a different polymorph upon desolvation. The crystal structure of this compound is obtained, revealing insights into its transient nature and the potential application …

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. …

Investigation Of Heavy Metal Removal From Synthetic Desalter Effluent Using A Two-Step Approach By Micellar-Enhanced Ultrafiltration And Microbial Fuel Cell, Carlos Munoz-Cupa

Electronic Thesis and Dissertation Repository

Heavy metals in wastewater streams negatively affect the environment due to their high toxicity. Non-conventional heavy metal removal methods show higher efficiencies for the remediation of these pollutants. In this investigation, a two-step approach using micellar-enhanced ultrafiltration (MEUF) and microbial fuel cell (MFC) was investigated to remove copper, manganese, and zinc from a synthetic salt wastewater containing magnesium, sodium, and phenol. This synthetic solution was used to simulate refinery wastewater streams such as desalter effluent. The study was carried out in three phases. In the first phase, a flat plate polyether sulfone membrane was investigated for the MEUF process with …

Corrosion Case Study On Automobile, Grace Ajayi, Xinran Pan, Geethu Sasikala, Marshall S. Yang

Chemistry Publications

No abstract provided.

Value Added Products From Nonconventional Agricultural Biomass Waste Through Thermochemical Transformation, Nicolas A. Sarmiento

Electronic Thesis and Dissertation Repository

The alteration of temperature patterns around the world has become noticeable in the recent decade. Sea level rise, wildfires, and high temperatures have made people realize that climate change is affecting humans more tangibly than ever. Therefore, the United Nations have pushed to make policies to mitigate this problematic situation. This research investigated the production of biochar from agricultural waste through pyrolysis for fighting climate change and adding value to waste. Experiments in a laboratory scale reactor were conducted to obtain yields of pyrolytic products. Then, analysis of products provided data for characterization and the LCA of the tomato plant …

Effect Of Process Parameters On The Mechanical Properties Of Carbon Fiber Epoxy Composites By Wet Compression Molding, Saboora Ayatollahi

Electronic Thesis and Dissertation Repository

In recent years, due to growing environmental concerns, composite materials have emerged as a promising lightweight alternative for metals in structural applications in automobiles. Among composite manufacturing processes, Wet Compression Molding (WCM) is a new method of producing Carbon Fiber Reinforced Polymer (CFRP) components. For similar processes like RTM, operating conditions are always one of the factors that impact the mechanical performance of CFRP parts. Thus, this thesis aimed to investigate the effects of operating conditions, including resin temperature, mold temperature, resin set time, gap closure speed, and mold curing time on the mechanical property of the composite parts. In …

Modeling And Multi-Objective Optimization Of Wastewater Treatment Process, Navneet Kaur

Electronic Thesis and Dissertation Repository

Wastewater is water that has already been used and requires treatment before releasing it into natural water bodies like lakes and rivers. Wastewater treatment is the process of removing impurities from wastewater. In this treatment process, the impurities are removed and converted to effluent. This effluent is returned to the water cycle with minimum impact on the environment. Conventional treatment plants consist of three stages: primary, secondary, and tertiary treatment. Treatment of wastewater is quite complicated because of the number of stages involved in this process. Most wastewater treatment plants are operated manually therefore at times it becomes difficult for …

Concentration Field Based Micropore Flow Rate Measurements, Matia P. Edwards, Samuel F. D. J. Gómez, Michael S. H. Boutilier

Chemical and Biochemical Engineering Publications

Demand is growing for a larger catalogue of experimental techniques to measure flow rates through micro-/nanoscale systems for both fundamental research and device development. Flow emerging from a hole in a plane wall is a common system of interest in such work for its relevance to membrane separation. In this paper, we consider the possibility of measuring volume flow rates through small scale orifice plates from images of dye dispersions downstream. Based on approximate analytical solutions to the advection–diffusion equation, we show that, at low Reynolds numbers, the concentration in the nearly hemispherical plume that forms increases linearly with inverse …

Direct Air Capture: Catalyzing A Carbon Negative Future, Tagg K. Lee

Civil and Environmental Engineering Publications

Direct Air Capture (DAC) technology has emerged as a promising means to address the escalating challenges of atmospheric carbon dioxide (CO₂) levels and mitigate climate change. This paper provides an elementary overview of DAC, encompassing its underlying principles, technological advancements, and associated challenges. Point Source Carbon Capture is compared against Direct Air Capture with a solid or liquid sorbent, and physisorbents/chemisorbents are outlined. The past decade has seen a steep rise in the usage of chemical sorbents in particular, which are explored alongside their regeneration processes. This review provides an introductory explanation for the mechanisms of common DAC …

Controlling Differentiation Of Adult Stem Cells Via Cell-Derived Nanoparticles: Implications In Bone Repair, Shruthi Polla Ravi, Yasmeen Shamiya, Aishik Chakraborty, Ali Coyle, Alap A. Zahid, Jin Wang, Michael Boutilier, Emmanuel Ho, Arghya Paul

Chemical and Biochemical Engineering Publications

No abstract provided.

Quantification Of Flows Emerging From Small Pores In Plane Walls, Matia Peter Edwards

Electronic Thesis and Dissertation Repository

Current membrane separation processes are limited in high production and high purity settings due to a trade-off between selectivity and permeance. Methods of creating nanoscale geometries in 2D materials are emerging and present an opportunity for fast, size selective mass transport that can be tailored to a wide array of applications. This thesis develops a method for quantifying flow through small pores in plane walls based on the behaviour of a solute dispersed in a downstream reservoir. This method is validated for a range of micropore diameters, for which flow rates can be calculated with confidence, and is shown to …

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 …

Teb 406 Reflection, Ryan Alfonso Falcon

Undergraduate Student Research Internships Conference

Slides for a non-exhaustive reflection on my work in summer

Improving The Crystal Habit Of Rufinamide, Peter M. Sadaka

Undergraduate Student Research Internships Conference

This research was developed by utilizing the knowledge gathered and learned about crystallization through my USRI project. The goal was to improve the crystal habit of a selected drug from the many that were available in the lab. To choose this, we looked at all of them and chose the drug with the worst habit and then began working. It was created by organizing my findings for each week and then making it all much more concise for the form of a simple presentation that most could understand.

Improving Electrical Properties Of Polypropylene/Gnp Composites Using Compatibilizer And Solvent-Assisted Melt Blending, Yazan Al Jawhari

Undergraduate Student Research Internships Conference

Over the past few years, polymer products have become essential to our lives. Many people may think that polymers are simply plastics, however, that is just the tip of the iceberg. Polymer products are used in food, sport, medical, and technological industries. There have been numerous applications in all these areas, but in the technological industry, electronic devices, in particular, are affected by electrostatic discharge (ESD) generated by friction during handling, packaging, or transportation. This requires the use of antistatic packaging, a special package that has low electrical resistivity in order to avoid electron accumulation.

This study is an attempt …

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 …

Developing Accurate Methods To Measure Pressure Fluctuations In Fluidized Beds, Lama Abdulal

Undergraduate Student Research Internships Conference

In gas-solid fluidized beds, pressure measurements provide essential information on bed hydrodynamics and any issues in signal detection. Because solids tend to pass through the line that connects a pressure tap[1]to a pressure transducer, a backflushing system helps to prevent the plugging of this line. This study focuses on designing the backflushed system to minimize any degradation in the pressure signal between the fluidized bed and the pressure transducer. To test, a vessel was pressurized to compare the responses of a backflushed system and a reference transducer to a sudden change in pressure. The results showed that the …

Development Of Photocatalytic Reactor System For Dye Degradation From Lab To Pilot Scale, Waleed Jadaa

Electronic Thesis and Dissertation Repository

The overall goal of the research is to develop a novel photocatalytic reactor system, namely, a bubble column photoreactor for the degradation of resistant pollutants, with a particular emphasis on azo dyes. To achieve the objective, different sub-objectives were performed employing lab and pilot-scale reactors with the application of simulated wastewater. Direct Blue (DB15) was used as a model compound for the azo dyes class for this study. Firstly, the influence of various variables such as pH, dye concentration, and catalyst loading to determine optimal combinations of DB15 removal. The experiments were conducted in a swirl flow photoreactor under the …

Novel Fed-Batch Process With In-Situ Product Recovery For Glycerol Fermentation To Butanol Using Clostridium Pasteurianum, Ammi Jani

Electronic Thesis and Dissertation Repository

Butanol, a next-generation biofuel, can be produced by fermenting glycerol using Clostridium pasteurianum. To address product inhibition, an integrated system that combined a fed-batch process with pervaporation was assessed against conventional batch and fed-batch fermentations. This study showed that with the novel process configuration, the productive fermentation time could be extended, translating to a 2.4-fold and 1.9-fold increase in butanol production relative to baseline fed-batch and batch operation, respectively. Further, it was demonstrated that butanol concentrations were able to be maintained below inhibitory levels throughout the fermentation. Despite this outcome, metabolic oscillations were revealed, indicating instability in the process. The …

Co-Gasification Of Biomass And Plastic Waste In A Bubbling Fluidized Bed Reactor, Islam Elghamrawy

Electronic Thesis and Dissertation Repository

Plastics are versatile, durable, and can be manipulated to match different needs. The COVID-19 pandemic has demonstrated the importance of reducing plastic waste and is believed to be responsible for increasing the generation of plastic waste by 54,000 tons/day which was reported in 2020. Another widely available waste is biomass waste. Agriculture and agroforestry, forest and wood processing, municipal waste, and the food industry are all considered major producers of biowaste. Co-gasification is considered one of the most promising methods of chemical recycling that targets the production of syngas (hydrogen and carbon monoxide) and light hydrocarbon gases. In this study, …

The Electrical, Thermal, And Morphological Properties Of Microinjection-Molded Polypropylene Nanocomposites, Renze Jiang

Electronic Thesis and Dissertation Repository

Microinjection molding (µIM) exhibits significantly higher shear rates and faster cooling rates, as compared to conventional injection molding, which affect the characteristics of its final products. The effect of carbon black (CB), carbon nanotubes (CNT), and graphene nanoplatelet (GNP) fillers on the electrical conductivity properties of microinjection-molded polypropylene (PP) nanocomposites was systematically studied. Results showed the electrical conductivity properties of PP/CNT and PP/CB microparts were significantly influenced by mold geometry. PP/CNT/CB hybrid filler microparts demonstrated synergistic increases in electrical conductivity and crystallization temperature with higher CNT loading. Morphological observations indicated significant CB and CNT phase separation. Powder-PP/GNP composites exhibited higher …

Sol-Gel Derived Bioceramic Poly(Diethyl Fumarate – Co – Triethoxyvinylsilane) Composite, Aref Sleiman

Electronic Thesis and Dissertation Repository

Synthetic bone graft materials have become an increasingly popular choice for bone augmentation. Ceramic-based and polymer-based bone graft materials constitute the two main classes of synthetic bone graft materials. This study investigated the synthesis of novel bioactive composites for their potential use as bone graft biomaterials. Poly(diethyl fumarate-co-triethoxyvinylsilane)/bioceramic class II organic/inorganic hybrid biomaterials were synthesized via a sol gel process. These biomaterials were then reacted with an ammonium phosphate solution to prepare their respective composites. For the first time, we successfully synthesized sol-gel derived bioceramic poly(diethyl fumarate-co-triethoxyvinylsilane) composites. In vitro bioactivity evaluation of poly(diethyl fumarate-co-triethoxyvinylsilane)/bioceramic composites in simulated body fluid …

The Greenest Solar Power? Life Cycle Assessment Of Foam-Based Flexible Floatovoltaics, Koami Soulemane Hayibo, Pierce Mayville, Joshua M. Pearce

Electrical and Computer Engineering Publications

This study presents a life cycle analysis (LCA) of a 10 MW foam-based floatovoltaics (FPV) plant installed on Lake Mead, Nevada, U.S. A material inventory of the flexible crystalline silicon (c-Si)-based module involved massing and determination of material composition of the module's encapsulation layers with ATR/FTR spectroscopy and electron microscopy. The LCA was performed using SimaPro and the results were interpreted in terms of cumulative energy demands, energy payback time, global warming potential, GHG emissions, and water footprint including negative values for reduced evaporation. A sensitivity analysis was performed on the lifetime of the modules and the foam-based racking. The …