Chemical Engineering Commons^™

Influence Of Single And Multiple Histidine Residues And Their Ionization Properties On Transmembrane Helix Dynamics, Orientations And Fraying, Fahmida Afrose

Graduate Theses and Dissertations

Since aromatic and charged residues are often present in various locations of transmembrane helices of integral membrane proteins, their impacts on the molecular properties of transmembrane proteins and their interactions with lipids are of particular interest in many studies. In this work, I used solid-state deuterium NMR spectroscopy in designed model peptide GWALP23 [GGALW(LA)6LWLAGA] with selective deuterium labels to addresses the pH dependence and influence of single and multiple “guest” histidine residues in the orientation and dynamic behaviors of transmembrane proteins. The mutations include Gly to His (G2/22 to H2/22), Trp to His (W5/19 to H5/19) and Leu to His …

Applications Of Ionic Liquids In Membrane Separation, Mohanad Kamaz

Graduate Theses and Dissertations

Ionic liquids represent an emerging attractive material in membrane technology. The central theme of this doctoral dissertation is to develope novel membranes using ionic liquids. Two different approaches were used to prepare ionic liquid membranes including the immobilization of ionic liquid within the membrane pores or the use of pressure assembly method to deposit a selective ionic liquid layer on the top membrane surface.

In chapter 2, imidazolium ionic liquids with three different alkyl halides were successfully synthesized and used to prepare supported ionic liquid membranes (SILMs). SILMs preraper were tested for aqueous and nonaqueous applications. For nonaqueous applications, the …

Development Of Forward Osmosis Based Separations: A Novel Approach In Membrane Technology, Yu-Hsuan Chiao

Graduate Theses and Dissertations

Tackling the worldwide severe water shortage, the membrane technology is considered to be the most efficient approach and hence, used widely as a cost-effective sustainable solution. “Forward osmosis (FO)” has been the major attention in recent time. FO uses osmotic pressure as the driving force to draw the water passing the membrane and achieve the desired separation performance. In general, it is considered to be a process with tremendous potential to resolve the present-day water shortage with extremely low energy consumption. However, the challenges of membrane and draw solution regeneration associated with FO processes must be conquered prior to their …

Design Of A System For Inexpensive Underwater Fiber Optic In Vivo Imaging And Mass Balance Accounting Of Tissue Engineering Candidates, Nicole Melissa Bueno Guerrero

Theses and Dissertations

The goal of this project is to create a prototype bioreactor that mimics a cell’s microenvironment. The ultimate goal is to set up an array of 36 bioreactors in parallel and monitor them with an array of sensors that will enable full mass and energy balance accounting and in vivo imaging. This thesis will analyze the various options available for cell imaging, as well as describe the construction of a bioreactor design in which cell images can be obtained without removing the cells from the bioreactor. The hypothesis for this project is that imaging of unstained cells in an aquarium …

Tracking Lysosome Migration Within Chinese Hamster Ovary (Cho) Cells Following Exposure To Nanosecond Pulsed Electric Fields, Gary L. Thompson Iii, Hope T. Beier, Bennett L. Ibey

Henry M. Rowan College of Engineering Departmental Research

Above a threshold electric field strength, 600 ns-duration pulsed electric field (nsPEF) exposure substantially porates and permeabilizes cellular plasma membranes in aqueous solution to many small ions. Repetitive exposures increase permeabilization to calcium ions (Ca²⁺) in a dosage-dependent manner. Such exposure conditions can create relatively long-lived pores that reseal after passive lateral diffusion of lipids should have closed the pores. One explanation for eventual pore resealing is active membrane repair, and an ubiquitous repair mechanism in mammalian cells is lysosome exocytosis. A previous study shows that intracellular lysosome movement halts upon a 16.2 kV/cm, 600-ns PEF exposure of …

Breaking Coastal Hypoxia: Destratification Of Gulf Of Mexico Deadzone To Encourage Oxygen Transport Downwards To Maintain Marine Fauna, Veda Thipparthi

LSU Master's Theses

As a consequence of seasonal eutrophication and human input, a vast hypoxic area termed The Dead Zone develops every year in the Gulf of Mexico (GOM) during summer along the Louisiana coastline characterized by vertical seawater density-stratification with oxygen concentrations less than 2 mg.l^-1 at the seafloor. It poses a threat to bottom-dwelling faunae and their environment which has negative ecological and economic consequences. This project aims to mitigate hypoxia by employing mechanical impellers placed at strategic water depths and locations in the Gulf. Enhanced transport of oxygen results by mixing oxygen-enriched seawater at the surface, downward into the …

Cgste11 Mediates Cross Tolerance To Multiple Environmental Stressors In Candida Glabrata, Mian Huang, Jibran Khan, Manpreet Kaur, Julian Daniel Torres Vanega, Orlando Andres Aguilar Patiño, Anand Ramasubramanian, Katy Kao

Faculty Publications

Candida glabrata is a human commensal and an opportunistic human fungal pathogen. It is more closely related to the model yeast Saccharomyces cerevisiae than other Candida spp. Compared with S. cerevisiae, C. glabrata exhibits higher innate tolerance to various environmental stressors, including hyperthermal stress. Here we investigate the molecular mechanisms of C. glabrata adaptation to heat stress via adaptive laboratory evolution. We show that all parallel evolved populations readily adapt to hyperthermal challenge (from 47 °C to 50 °C) and exhibit convergence in evolved phenotypes with extensive cross-tolerance to various other environmental stressors such as oxidants, acids, and alcohols. Genome …

Understanding The Role Of Complexation In The Charge-Transfer Kinetics Of The Cu2+ + E ↔ Cu1+ Redox Reaction In Ethaline Deep Eutectic Solvent, Dai Shen, Rohan Akolkar

Faculty Scholarship

Deep eutectic solvent (DES) based electrolytes are gaining attention for electrochemical applications. As such, knowledge of the charge transfer kinetics in DES and its dependence on electrolyte composition and temperature is important. Using Cu2+ + e ↔ Cu1+ as a model system, we demonstrate that metal redox reactions in chloride-containing DES media suffer from sluggish charge transfer kinetics. The exchange current density, i0, displayed a peculiar inverse relationship with the bulk chloride concentration, [Cl−]b. The i0 decreased from 7.9 to 3.0 mA/cm2 when [Cl−]b increased from 2.8 to 4.6 M at 30°C. Such dependence is shown to originate from Cl− …

In-Situ Extraction And Impregnation Of Black Walnut Husk Into Polyethylene Film Using Supercritical Carbon Dioxide With An Ethanol Modifier, Johnathon Wenzel, Veronica Moorman, Lihua Wang, Cheryl S. Samaniego, Michelle Ammerman, Isaiah Spencer-Williams, Mitchell Hall

Chemical Engineering Publications

Walnuts are commonly cultivated for their kernel, which is a rich source of antioxidant phenolic compounds. The husk likewise contains antioxidant and antimicrobial compounds, but is typically discarded without further processing. Antioxidant compounds are useful in creating active packaging films, but typically decompose at melt extrusion temperatures in polymer processing. Due to carbon dioxide's low critical point and ability to swell polymer films, supercritical carbon dioxide may be used to impregnate phenolic compounds into polymers. For this study, a novel technique is used to simultaneously produce walnut husk extracts and impregnate the extract into polymer films in the same batch …

The Effects Of Temperature On The Yields Of Aliphatic And Aromatic Products From The Supercritical Pyrolysis Of 1-Octene, Elizabeth Anne Hurst

LSU Doctoral Dissertations

Prior to their combustion, fuels for future high-speed aircraft are expected to experience supercritical conditions, leading to the production of polycyclic aromatic hydrocarbons (PAH), precursors to solid carbonaceous deposits, via pyrolytic reactions. These solid deposits can clog fuel-transfer lines, causing unsafe aircraft operation. To prevent the formation of fuel-line deposits, it is critical to understand the reaction pathways that lead to PAH formation in the supercritical fuel pyrolysis environment.

To better understand the role of large 1-alkenes in PAH formation, supercritical pyrolysis experiments with model fuel 1-octene, a representative 1-alkene product from supercritical n-alkane pyrolysis, have been performed. The …

Decorative Articles Based On Polymeric Materials, Bassant Hussein, Yasser M. Asal, M. A. Radwan, M. A. Sadek, Hany A. Elazab

Chemical Engineering

The aim of the research is to create decorative articles based on polymeric materials, study the effects of fillers and the type of moulds that it can cope with the exothermic reaction nature of resin to create a scientific background on the usage of the resins in daily life products. The polymeric materials that will be concentrated on are the unsaturated polyester resins and epoxy resins. The unsaturated polyester is of many types and chemical constituents, the used experimentally is a general-purpose type and the epoxy also have different types and the used is a commercially 3D floor coating type. …

Amélioration De La Justesse Des Modèles D’Hygiène Du Travail Utilisés Pour Estimer Des Expositions Professionnelles À Des Vapeurs De Solvants, Spéro Abattan, Stéphane Hallé, Daniel Drolet, Ali Bahloul, Patrick Eddy Ryan, Wejden Chouchene, Carlos Castro Ruiz, Jérôme Lavoué, Maximilien Debia

Rapports de recherche scientifique

Chaque année, des travailleurs québécois subissent des effets sur leur santé après avoir été exposés à des substances chimiques, notamment à des solvants. La modélisation des expositions professionnelles occupe une place importante dans la prévention des risques. Cette recherche vise à étudier différents aspects de la modélisation pour estimer des expositions professionnelles à des vapeurs de solvants dans le but d’en améliorer la justesse de prédiction. Le travail de recherche a été effectué en deux volets. Grâce à la mise en œuvre de tests à petite échelle (volet I) et à échelle humaine (volet II), les travaux présentés dans cette …

Cactus-Based Mucilage As A Natural Dispersant For Crude Oil Spills, Fei Guo

USF Tampa Graduate Theses and Dissertations

Oil spills are a critical threat to the marine environment, and the spilled oil as a source of pollution can have long-term adverse effects on the marine ecosystem. Traditional mechanical clean-up operations have apparent advantages for dealing with small and medium-scale oil spills. For large-scale oil spills, dispersants are a practical and minimally influential approach to the environment. As the dispersant components are iteratively updated, dispersants become more efficient and safer. However, the toxicity of the dispersants remains a significant impediment to their application. An efficient and non-toxic dispersant is increasingly becoming a requirement.

The cactus mucilage extracts studied in …

Microwave Assisted Synthesis Of Binary Metallic Oxides For Catalysis Applications, Abdelrahman Mostafa Kamal, Sherif Bahgat, Mohammed Hammam, M. A. Radwan, M. A. Sadek, Hany A. Elazab

Chemical Engineering

Herein, versatile, and reproducible method to prepare binary metal oxides via microwave assisted synthesis. Catalysts are substances that basically speeds up chemical reactions. Ideally, bonds are formed between the catalysts and the reactants. Also, catalysts permits formation of products from the reactants. These formed products, splits off the catalyst without affecting or changing it. Catalytic kinetics studies the correlate chemical reaction rate with some properties of reactants and/or products for instance; temperature, concentration and pressure. The aim of the project is to prepare pure and bi-metal iron based catalyst by co-precipitation method and to characterize the prepared sample using X-ray …

Novel Adsorbent For Industrial Wastewater Treatment Applications, Ahmed Y. Zakaria, Dalia A. Ali, Islam M. Al-Akraa, Hoda A. Elsawy, Hany A. Elazab

Chemical Engineering

In this study, the hydroxyapatite powder is investigated for both of methylene blue and thymol blue in aqueous solution. The physical and chemical properties of the adsorbent were evaluated systematically using the different techniques including Microsoft Excel programming, linear regression model and also the coefficient of determination. Batch adsorption experiments were conducted to determine the effect of contact time, solution pH, initial dye concentrations, and also the adsorbent dosage on adsorption. The adsorption kinetic parameters confirmed the better fitting of pseudo-second order kinetic model for both of methylene blue and thymol blue. The isotherm data of methylene blue and thymol …

Gradient Precipitation Of Recombinant Proteins Contained In Silkworm Larvae (Bombyx Mori) With Ammonium Sulphate, Abdurhakhmanov Jaloliddin, Sasmakov Sobirdjan, Khasanov Shuhrat, Ashirov Оybek

CHEMISTRY AND CHEMICAL ENGINEERING

We investigated the protein extract of silkworm larvae. For the first time, an extract containing proteins from silkworm larvae, obtained by fractional precipitation using ammonium sulfate, was studied. As a result of experiment is established, that solutions of ammonium sulfate with a concentration from 20% to 65% are optimal for the sedimentation of protein molecules with a mass in the range of 25 and 45 kDa. Optimal results of the study proposed to use in the process of purification of recombinant proteins.

Extraction-Photometric Determination Of Bismuth (Iii) With 1-(2-Pyridylaze)-2-Naphthol, Turabdjanov Sadritdin, Otakuzieva Vazira, Giyasov Anvar, Rakhmatullaeva Nargiza

CHEMISTRY AND CHEMICAL ENGINEERING

The conditions of selective extraction of the bismuth (III) by inert organic solvents in the presence of DMFA are established. The conditions for complex formation of the bismuth (III) with the PAN directly in the organic phase are found. It is possible to increase the sensitivity of the methodology using more sensitive azoreagents that have not found the application in practice due to their low selectivity. The effect of extraneous ions on the results of the definition of the bismuth (III) with the PAN azoreagent is investigated. In the presence of large amounts of extraneous ions the determination of bismuth …

Analysis Of Experimental Research In Determining Bubbling Extractor Mixing Zones’ Sizes, Karimov Ikromali

CHEMISTRY AND CHEMICAL ENGINEERING

In the inner mixing zone of the tested suspended extractor, the fluid and gas flows in the stream and the external mixing zone moves in a contradictory flow. In order for these mixing zones to operate equally in hydrodynamic mode, their gas values should be equal. This is achieved by the correct selection of the dimensions of the mixing zones of the liquid and gas. The article summarizes the results of the study of the measurement of the mixing zones of the apparatus.

Composite Materials Based On Twaron And Nano Materials, Omnia Hamdy, Remon A. Mankarious, M. A. Radwan, M. A. Sadek, Hany A. Elazab

Chemical Engineering

This research aims to participate in producing body shield that can overcome pervious drawbacks using behaviour of shear thickening fluid. Initially, the rheological behaviour of silica-polyethylene glycol shear thickening fluid is examined at different concentrations. Then, ballistic fabric samples are impregnated into silica-polyethylene glycol shear thickening fluid at various concentrations of silica and tested using gas gun simulating real ballistic threat. After that, the impact of rubbery hot water pack filled with around 66.67 wt% starch in water is tested using gas gun. Results showed as the concentration of silica increases, the indentation depth in the impregnated fabric decreases which …

Periodic Operation Of A Dynamic Dna Origami Structure Utilizing The Hydrophilic–Hydrophobic Phase‐Transition Of Stimulus‐Sensitive Polypeptides, Marisa A. Goetzfried, Kilian Vogele, Andrea Mückl, Marcus Kaiser, Nolan B. Holland, Friedrich C. Simmel, Tobias Pirzer

Chemical & Biomedical Engineering Faculty Publications

Dynamic DNA nanodevices are designed to perform structure‐encoded motion actuated by a variety of different physicochemical stimuli. In this context, hybrid devices utilizing other components than DNA have the potential to considerably expand the library of functionalities. Here, the reversible reconfiguration of a DNA origami structure using the stimulus sensitivity of elastin‐like polypeptides is reported. To this end, a rectangular sheet made using the DNA origami technique is functionalized with these peptides and by applying changes in salt concentration the hydrophilic–hydrophobic phase transition of these peptides actuate the folding of the structure. The on‐demand and reversible switching of the rectangle …