Chemical Engineering Commons^™

Modeling Solvent Extraction Of Lignin From Hardwoods, Su Pan

McKelvey School of Engineering Graduate Student Theses & Dissertations

This study interprets the observed behavior of solvent extraction of lignin from hardwoods by adapting the framework of the FLASHCHAIN theory (Niksa and Kerstein, 1991; Niksa, 2017). A constitution submodel specifies distributions of molecular weight and reactive sites for native lignin. The model simulates delignification as depolymerization of lignin macromolecules into fragments small enough to be soluble. This process competes with intrachain condensation that consumes labile bridges without forming new fragments, and with recombination that forms larger chains and inhibits further depolymerization. After the soluble fragments are transported from the particle into the bulk solvent, all chemistry continues as long …

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. …

Thermo-Responsive Hydrophilic Support For Polyamide Thin-Film Composite Membranes With Competitive Nanofiltration Performance, Haniyeh Najafvand Drikvand, Mitra Golgoli, Masoumeh Zargar, Mathias Ulbricht, Siamak Nejati, Yaghoub Mansourpanah

Research outputs 2022 to 2026

Poly(N-isopropylacrylamide) (PNIPAAm) was introduced into a polyethylene terephthalate (PET) nonwoven fabric to develop novel support for polyamide (PA) thin-film composite (TFC) membranes without using a microporous support layer. First, temperature-responsive PNIPAAm hydrogel was prepared by reactive pore-filling to adjust the pore size of non-woven fabric, creating hydrophilic support. The developed PET-based support was then used to fabricate PA TFC membranes via interfacial polymerization. SEM–EDX and AFM results confirmed the successful fabrication of hydrogel-integrated non-woven fabric and PA TFC membranes. The newly developed PA TFC membrane demonstrated an average water permeability of 1 L/m2 h bar, and an NaCl rejection of …

Machining Of Carbon Steel Under Aqueous Environment: Investigations Into Some Performance Measures, Mushtaq Ali, Tahir Abdul Hussain Ratlamwala, Ghulam Hussain, Tauheed Shehbaz, Riaz Muhammad, Muhammad Aamir, Khaled Giasin, Danil Yurievich Pimenov

Research outputs 2022 to 2026

In this study, a new machining approach (aqueous machining) is applied for mill machining and its performance is compared with traditional wet machining. AISI 1020 steel is employed as the test material and Taguchi statistical methodology is implemented to analyze and compare the performance of the two machining approaches. The cutting speed, feed rate, and depth of cut were the machining parameters used for both types of machining, while the selected response variables were surface roughness and hardness. Temperature variations were also recorded in aqueous machining. Compared with wet machining, aqueous machining resulted in lower surface roughness (up to 13 …

Myosin Ii Adjusts Motility Properties And Regulates Force Production Based On Motor Environment, Omayma Y. Al Azzam, Janie C. Watts, Justin E. Reynolds, Juliana E. Davis, Dana N. Reinemann

Faculty and Student Publications

Introduction—Myosin II has been investigated with optical trapping, but single motor-filament assay arrangements are not reflective of the complex cellular environment. To understand how myosin interactions propagate up in scale to accomplish system force generation, we devised a novel actomyosin ensemble optical trapping assay that reflects the hierarchy and compliancy of a physiological environment and is modular for interrogating force effectors.

Methods—Hierarchical actomyosin bundles were formed in vitro. Fluorescent template and cargo actin filaments (AF) were assembled in a flow cell and bundled by myosin. Beads were added in the presence of ATP to bind the cargo AF …

Study Of Water Desalination: A Persian Gulf City, Grégoire Saury

Student Theses and Dissertations

Water desalination represents an important challenge of tomorrow’s world. Water needs never stop to increase and certain areas of the world relies on ways to have access to this resource. Desalination is a process that offers an alternative access to this vital resource by using seawater as process input. These installations are implementing several purifications units designed to transform seawater into drinkable water. So, they eliminate salt but also any kind of pollution present in the water. Here, the goal will be to design a process able to provide drinkable water for a 200,000 habitants town located in the Persian …

Preface Of Volume 1 Issue 1 On Journal Of Materials Exploration And Findings (Jmef), Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.

The Optimization Of Failure Risk Estimation On The Uniform Corrosion Rate With A Non-Linear Function, Fernanda Hartoyo, Jaka Fajar Fatriansyah, Imam Abdillah Mas'ud, Farhan Rama Digita, Hanna Ovelia, D. Rizal Asral

Journal of Materials Exploration and Findings

Failures in the oil and gas pipeline system are conditions that must be avoided and anticipated because the losses due to the failures can occur at a very high level. Internal corrosion is one of the significant causes of the failures in pipeline systems. In addition, this type of corrosion is due to the high content of carbon dioxide and other corrosive substances in crude oil and natural gas. Therefore, an optimal inspection scheduling system is required to prevent the possibility of pipeline failures due to corrosion and to avoid any overspending on the budget due to excessive inspection scheduling. …

Contents, Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.

Advancing Water Resource Assessment With Insar Data And Subsidence Models, Ryan G. Smith

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Over the past three decades, Interferometric Synthetic Aperture Radar (InSAR) has grown from a tool for monitoring earthquakes and other massive signature deformation events to tracking the subtle, slow deformation processes associated with changes in groundwater storage. Improvements in time-series processing and noise reduction, as well as improved models of deformation, have enabled this advancement. InSAR has proven to be a valuable tool for characterizing elastic deformation in regions experiencing little long-term storage loss, as well as inelastic deformation in over-stressed aquifers.

Dynamics Of Spatiotemporal Heterogeneities In Particulate Intercalation Electrodes, Shubham Agrawal

McKelvey School of Engineering Graduate Student Theses & Dissertations

Electrochemical energy systems rely on particulate porous electrodes to store or convert energies. While the three-dimensional porous structures of the electrodes were introduced to maximize the interfacial area for better overall performance of the system, spatiotemporal heterogeneities arising from materials thermodynamics localize the charge transfer processes onto a limited portion of the available interfaces. These reaction heterogeneities may cause local hot and cold spots, and early battery failures. This dissertation focuses on the following three aspects of the dynamic reaction heterogeneities in the particulate cathodes and anodes in the lithium-ion batteries: (i) the real-time evolution of reaction heterogeneities in graphite …

Nano-Bio Interactions: Implications And Applications, Anushree Ghosh

McKelvey School of Engineering Graduate Student Theses & Dissertations

Rapid expansion of technology development at the nanoscale has underpinned a promising industry. Towards this, there remain significant information gaps which are critical with regard to decision making processes and ultimate industrial sustainability. From an implication point of view, understanding how common biological macromolecules, including glycolipids and/or biopolymers produced by bacteria and fungi, which are ubiquitous in the environment, is fundamental to predicting the behavior of released/produced nanoparticles. Conversely, other bio-based tailored macromolecules, including mussel foot protein (MFP), have significant potential as functional material coatings for advanced applications.This PhD thesis is focused on interfacial processes related to superparamagnetic iron oxide …

Nanoscale Interfacial Control Of Ion Behaviors And Caco3 Formation In Environmental Systems, Yaguang Zhu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Interfaces in environmental systems can change the distribution of pollutants and nutrients, determine the fate and transport of nanoparticles, and affect the efficiency of engineering projects. Complex interactions, including electrostatic interactions, Van der Waals interactions, chemical interactions, and ion-surface specific interactions, can all contribute to different ion, ion-pair, and nanoparticle formations near interfaces. Although environmental interfaces play critical roles, only a limited number of studies have considered the nanoscale picture of how they control ions and nanoparticles. Thus, this dissertation addresses three research questions: (1) How does sulfate chemically interact with calcium carbonate (CaCO3) during its heterogeneous formation on quartz …

The Generation And Transport Of Charged Aerosols: Fundamental Study And Applications In Medicine And Energy Conversion, Hao Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Charged aerosols have significant implications in the field of functional material synthesis, pharmaceutical coating, and drug delivery. Electrospray systems are an effective methodology for generating highly charged monodispersed droplets in the size range from nanometer to micrometer. The prediction of surface charge, size and morphology of nanoparticles resulting from charged droplets are highly required for the precise control of nanoparticle properties and their effective utilization. However, the evolution of charged droplet is not well understood due to the existence of coulombic fission and ion evaporation processes. Thus, the goal of this dissertation is to elucidate how the precursor properties and …

Lead(Iv) Oxide In Drinking Water Systems: Formation, Dissolution, Redox-Driven Recrystallization, And Implications For Lead Control, Weiyi Pan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Lead (Pb) in tap water is mainly contributed by lead service lines (LSLs). The dissolved lead concentration is controlled by the solubilities of lead corrosion products that form on the inner surface of LSLs. Among these lead corrosion products, lead(IV) oxide (PbO2) has the lowest solubility and can maintain a low lead level when free chlorine is present. Current strategies to control the lead concentration include replacing the LSL, optimizing the water chemistry conditions, and using point-of-use (POU) filters. The present study investigated the effect of manganese (Mn) on the oxidation of the lead(II) carbonate solids by free chlorine, the …

Synthesis And Consolidation Of Metal Oxide Nanocrystals Via Nonthermal Plasma, Austin Cendejas

McKelvey School of Engineering Graduate Student Theses & Dissertations

Nonthermal plasmas offer a unique nonequilibrium environment that has been leveraged in a wide variety of applications in the fields of material processing, lighting, and waste management to name a few. In all of these cases, the plasma serves as a source of high energy electrons, ions, reactive gas species, and radicals that interact in several ways with surfaces brought into contact with the plasma. Specifically, nonthermal plasmas have been shown to be very successful in achieving continuous, high-throughput, monodisperse nanocrystals of a wide variety of materials. The crystallinity of nanoparticles synthesized in nonthermal plasmas can be attributed to the …

Droplet Dynamics And Heat Transfer During Condensation On Lubricant-Infused Surfaces, Jianxing Sun

McKelvey School of Engineering Graduate Student Theses & Dissertations

Inspired by pitcher plants, a micro/nano- structured solid surface infused with low-surface-tension lubricant constitutes a novel class of biomimetic surfaces—lubricant-infused surfaces (LISs). Unlike solid hydrophobic and superhydrophobic surfaces, a LIS is “hemi-solid and hemi-liquid”. The thin lubricating film can extraordinarily decrease adhesion and avoid contact line pinning between the working fluid and the underlying solid, displaying many desirable properties, such as excellent liquid repellency, suppression of fouling, and self-healing. Hence, LISs are ideal for applications where liquids or contaminants must be efficiently removed from surfaces in harsh environments. For example, LISs can promote stable dropwise condensation of water or low-surface-tension …

Droplet-Based Two-Phase Thermal Management, Junhui Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

The rapid development of electronic systems with ever-higher power densities in a wide range of applications requires new advanced thermal management methods. Droplet-based two-phase thermal management technologies are considered promising solutions to conquer the cooling challenges in the electronic industries. The heat transfer behavior of droplets is based on several important fundamental processes, such as droplet evaporation, droplet impact on heated surfaces, and molten droplet impact. In this dissertation, four research projects are completed to explore the insights of these fundamental processes. For droplet evaporation, I introduce an investigation of diffusion confinement of droplets evaporating on a supported pillar structure. …

Photochemical Formation Mechanisms And Applications Of Mn Oxide Nanomaterials, Zhenwei Gao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Manganese (Mn) oxides are ubiquitous in aquatic and terrestrial environments, and the rich redox chemistry of manganese is of interest in engineered systems, such as batteries and water oxidation catalysts. Mn oxides have large surface areas and are highly active in adsorption and redox reactions. Our research group recently reported photochemically-assisted abiotic inorganic oxidation of Mn2+(aq) to δ-MnO2 nanosheets in the presence of nitrate and without a microorganism, demonstrating that abiotic Mn oxidation processes are not negligible. My doctoral work focuses on investigating the effects of various aquatic chemistry parameters, including reactive oxygen species (ROS), peroxyl radical (ROO•), reactive halogen …

Advanced Nanomaterials And Module Designs For Efficient Photothermal Water Treatment, Deoukchen Ghim

McKelvey School of Engineering Graduate Student Theses & Dissertations

Water scarcity is one of the most serious challenges that human beings face, and the demand for clean water will continuously increase as populations grow. Creating potable water from saline water is an important way to meet global freshwater demands. However, current desalination techniques require high energy consumption and a large scale to be efficient, restricting their utilization in remote and underdeveloped areas. These constraints motivate the development of sustainable water treatment methods that can be used with less energy input, in small modular configurations, and in off-grid water treatment systems. As an abundant and renewable energy source, sunlight has …