Chemical Engineering Commons^™

Limited Thermal Conductance Of Metal-Carbon Interfaces, Jaime J. Gengler, Sergei V. Shenogin, John E. Bultman, Ajit K. Roy, Andrey A. Voevodin, Christopher Muratore

Chemical and Materials Engineering Faculty Publications

The thermal conductance for a series of metal-graphite interfaces has been experimentally measured with time-domain thermoreflectance (TDTR). For metals with Debye temperatures up to ∼400 K, a linear relationship exists with the thermal conductance values. For metals with Debye temperatures in excess of ∼400 K, the measured metal-graphite thermal conductance values remain constant near 60 MW m−2 K−1. Titanium showed slightly higher conductance than aluminum, despite the closeness of atomic mass and Debye temperature for the two metals. Surface analysis was used to identify the presence of titaniumcarbide at the interface in contrast to the aluminum and gold-carbon interfaces (with …

Design Mixers To Minimize Effects Of Erosion And Corrosion Erosion, Julian B. Fasano, Eric E. Janz, Kevin J. Myers

Chemical and Materials Engineering Faculty Publications

A thorough review of the major parameters that affect solid-liquid slurry wear on impellers and techniques for minimizing wear is presented. These major parameters include (i) chemical environment, (ii) hardness of solids, (iii) density of solids, (iv) percent solids, (v) shape of solids, (vi) fluid regime (turbulent, transitional, or laminar), (vii) hardness of the mixer's wetted parts, (viii) hydraulic efficiency of the impeller (kinetic energy dissipation rates near the impeller blades), (ix) impact velocity, and (x) impact frequency. Techniques for minimizing the wear on impellers cover the choice of impeller, size and speed of the impeller, alloy selection, and surface …

Organic Photovoltaics: A Charge Transfer Perspective In The Study Of Donor-Acceptor Pairs, Marco Olguin

Open Access Theses & Dissertations

The present research involves the study of donor-acceptor (D/A) dyad complexes from a charge transfer energy perspective. The aim is to provide insight and predictive understanding into the charge transfer processes of the molecular-level components in donor-acceptor based organic solar cells using computational methods to describe photochemical processes at the quantum mechanical level within the Density Functional Theory (DFT) approximation. Predictive understanding is anchored in reproducing experimental results, wherein the present work a perturbative excited-state DFT method is described in detail and shown to give CT energies in excellent agreement with benchmark experimental data. With an accurate excited state method …

A Review Of Some Subtleties Of Practical Relevance, Keqin Gu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper reviews some subtleties in time-delay systems of neutral type that are believed to be of particular relevance in practice. Both traditional formulation and the coupled differential-difference equation formulation are used. The discontinuity of the spectrum as a function of delays is discussed. Conditions to guarantee stability under small parameter variations are given. A number of subjects that have been discussed in the literature, often using different methods, are reviewed to illustrate some fundamental concepts. These include systems with small delays, the sensitivity of Smith predictor to small delay mismatch, and the discrete implementation of distributed-delay feedback control. The …

Admicellar Polymerization Of Calcium Carbonate And Its Performance In Drilling Fluids, Poh Lee Cheah

Electronic Theses and Dissertations

Admicellar polymerization using sodium dodecylsulfate (SDS) template to form ultrafilm polystyrene on commercial calcium carbonate (CaCO3 ) of various particle sizes was studied. Adsorption isotherms of SDS decrease after the critical micelle concentration (CMC) of SDS was observed. This is explained by the phase behavior of SDS with calcium ion. The solubility product constants (Ksp) for calcium dodecylsulfate (Ca(DS) 2) were calculated as 1.55x10?9M3 at 30°C and 8.58x10?9M3 at 50°C. At SDS concentrations above the CMC, precipitation of Ca(DS)2 was governed by the critical ratio of calcium ion concentration bound onto anionic micelles which was 0.22 at 30°C and 0.20 …

Heat Transfer Enhancement In A Straight Channel Via A Rotationally Oscillating Adiabatic Cylinder, Ali Beskok, Mehrdad Raisee, Bayram Celik, Bedri Yagiz, Mohsen Cheraghi

Mechanical & Aerospace Engineering Faculty Publications

Heat convection from the uniformly heated walls of a straight channel in presence of a rotationally oscillating cylinder (ROC) is simulated at Re = 100. Heat transfer enhancement due to vortex shedding from the ROC is investigated. Systematic studies are performed to explore the rotation angle and frequency influences on heat transfer by varying the latter in range of the lock-in regime and the former from 0 to 2 π/3. All simulation results are based on the numerical solutions of two-dimensional, unsteady, incompressible Navier-Stokes and energy equations using an h/p type finite element algorithm. Considering time periodicity of the resulting …

Airlift Column Photobioreactors For Porphyridium Sp. Culturing: Part Ii. Verification Of Dynamic Growth Rate Model For Reactor Performance Evaluation, Hu Ping Luo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Dynamic Growth Rate Model Has Been Developed to Quantify the Impact of Hydrodynamics on the Growth of Photosynthetic Microorganisms and to Predict the Photobioreactor Performance. Rigorous Verification of Such Reactor Models, However, is Rare in the Literature. in This Part of Work, Verification of a Dynamic Growth Rate Model Developed in Luo and Al-Dahhan (2004) [Biotech Bioeng 85(4): 382-393.] Was Attempted using the Experimental Results Reported in Part I of This Work and Results from Literature. the Irradiance Distribution Inside the Studied Reactor Was Also Measured at Different Optical Densities and Successfully Correlated by the Lambert-Beer Law. When Reliable Hydrodynamic …

Quantifying Cell-To-Cell Variations In Lithium Ion Batteries, Shriram Santhanagopalan, Ralph E. White

Faculty Publications

Lithium ion batteries have conventionally been manufactured in small capacities but large volumes for consumer electronics applications. More recently, the industry has seen a surge in the individual cell capacities, as well as the number of cells used to build modules and packs. Reducing cell-to-cell and lot-to-lot variations has been identified as one of the major means to reduce the rejection rate when building the packs as well as to improve pack durability. The tight quality control measures have been passed on from the pack manufactures to the companies building the individual cells and in turn to the components. This …

Functionalized Silica Materials And Mixed-Matrix Membranes For Environmental Applications, Noah Daniel Meeks

Theses and Dissertations--Chemical and Materials Engineering

Functionalized silica materials are synthesized for various environmental applications. The overall objective is functionalization with sulfur-containing moieties for mercury sorption and as a platform for nanoparticle synthesis. The first objective is quantifying this functionalization for various silica platforms. The second objective is development of effective mercury sorbents, for both aqueous mercury and elemental mercury vapor. Third, those sorbents are incorporated into mixed matrix membranes (MMM) for aqueous mercury sorption. Fourth, functionalized silica materials are developed as platforms for the synthesis of reactive metal nanoparticles (NP) for the degradation of trichloroethylene.

Thiol-functionalized silica is used as a sorbent for aqueous mercury, …

Development Of Strategies To Minimize The Release Of Trace Elements From Coal Waste Sources, Mohammad Rezaee

Theses and Dissertations--Mining Engineering

To assess strategies aimed at minimizing the release of trace elements and the impact of disposal of coal waste materials on the environment, two long-term leaching experiments of up to five months duration were performed using waste materials from two plants cleaning high and low sulfur bituminous coal. The tests evaluated the mobility of major trace elements under different disposal scenarios: (i) a static leaching test designed to simulate the quiescent conditions encountered by coal waste material stored under water in a stable impoundment, and (ii) a dynamic test to simulate waste materials exposed to the atmosphere, either in variable …

Differential Gene Expression In A Louisiana Strain Of Microalgae, John Joseph Tate

LSU Master's Theses

Considerable interest in alternative energy has stimulated research in biofuels, particularly microalgal biofuels. In particular, strains of algae that accumulate lipids to be used for biofuels must be adapted to outdoor growth and resistant to invasive species. Differential gene expression in a Louisiana algae/cyanobacteria co-culture consisting of approximately 97% Chlorella vulgaris and 3% Leptolyngbya sp. possessing these traits was examined. Possible reasons for the enhanced growth of the co-culture relative to a Chlorella monoculture were reviewed, including cyanobacterial symbiosis and chemicals produced by cyanobacteria or bacteria that could influence the growth of Chlorella. The co-culture and Chlorella monoculture were cultivated …

Design And Optimization Of 2.5 Dimension Porous Media Micromodel For Nanosensor Flow Experiments, Saade Alexis Bou-Mikael

LSU Master's Theses

Micromodels are used to visualize and study pore-scale phenomena such as immiscible displacements in porous media, foam flow behavior, and CO2 flooding. The understanding gained from these experiments can be used to develop models to predict future behavior of the reservoir. Most micromodels are constructed using lithography techniques that are restricted to 2D patterns that require artificial generation or manipulation of images to develop connected micromodels. Characteristics innate to the original rock structure are often lost or skewed in developing micromodels that bear little resemblance to the original media. Alternative microfabrication techniques using a micromilling tool have allowed us to …

Double-Bond Isomerization Of Long Chain Olefins, James Edward Bruno

LSU Master's Theses

Bruno, James Edward, B.S., Western Michigan University, 2010 Master of Science, Fall Commencement, 2012 Major: Chemical Engineering Double-Bond Isomerization of Long Chain Olefins Thesis directed by Professor Kerry Dooley Pages in thesis, 54. Words in Abstract, 349. ABSTRACT Alkenyl Succinic Anhydride (ASA) is commonly used in the paper industry as a sizing agent. ASA is produced by reacting maleic anhydride with long-chain internal olefins. Such olefins are only available with the double bond in the terminal position, so an isomerization step is necessary. The isomerization can be catalyzed using solid strong acid catalysts, such as those containing sulfonic acid groups. …

Boron Composite Nanoparticles For Enhancement Of Bio-Fuel Combustion, Neng Wang

LSU Master's Theses

Bio-fuels such as ethanol are good candidates to replace fossil fuels, which are being depleted, and whose combustion is associated with net production of greenhouse gases and other environmental issues. However, bio-fuels have low energy densities and can be subject to incomplete combustion. Boron is a promising additive for bio-fuels in combustion applications. It can increase their overall heat release and reduce ignition temperature, because boron itself is among the highest energy density materials. In this study, different B/rare earth oxide and B/Fe composite nanoparticles were produced by simple mechanical milling. Also, a new low temperature milling method was developed …

A Novel Rna Extraction Method For Cyanobacteria, Zenghui Zhang

LSU Master's Theses

Research on production of polyhydroxyalkanoates (PHA) by microorganisms has captured attention over the last two decades, since PHA have similar properties as petroleum-based thermoplastics, yet are close to carbon neutral and made from renewable sources. Cyanobacteria are considered to be good PHA producers because of their simple nutrient requirements (mainly water, sunlight and CO2) and fast cell growth. However, knowledge of metabolisms behind PHA production by cyanobacteria is limited. Therefore, gene expression analysis of cyanobacteria is required to get a thorough understanding at the molecular level, and gene expression analysis requires the extraction of high quality RNA. Extracting high quality …

A Review Of Offshore Blowouts And Spills To Determine Desirable Capabilities Of A Subsea Capping Stack, Louise Matilde Smith

LSU Master's Theses

The events surrounding the Deepwater Horizon disaster have changed the face of deepwater operations. In order to continue drilling in the Gulf of Mexico, the regulatory body, the Bureau of Safety and Environmental Enforcement (BSEE), has required that applications to conduct work in the Gulf of Mexico (GOM) include a plan to stop, capture, or contain any uncontrolled release of fluids. The capping and containment systems built and implemented by BP during the event are an excellent starting point for minimizing pollution from deepwater subsea blowouts, but the system has limitations. The industry recognizes these limits but is currently focused …

Catalytic Oxidative Desulfurization: A Comparison Of Reactors, Andrew Marshall Madrid

LSU Master's Theses

A novel technology, a pulsed oscillating monolith reactor (POMR), was compared to a standard autoclave reactor for oxidative desulfurization (ODS) of a model diesel fuel. Two classes of catalysts, mesoporous Ti-MCM-41 and Pd on carbon, were used for ODS. The oxidants used were O2 and peroxide. The model diesel compound was 75 wt% alkanes, 24 wt% alkylaromatic, 0.95 wt% sulfur heterocycles and 0.05% nitrogen heterocycles. ODS reactions were conducted from 343-423 K and pressures from 1.0-1.3 MPa O2. The only component that was not oxidized was the alkane. The POMR showed promise; there was up to a factor of 20 …

Experimental Study Of The Effect Of Drilling Fluid Contamination On The Integrity Of Cement-Formation Interface, Nnamdi Charles Agbasimalo

LSU Master's Theses

Well cementing is one of the key processes performed during drilling and completion of wells. The main objective of primary cementing is to provide zonal isolation. Failure of cement to provide zonal isolation can lead to contamination of fresh water aquifers, sustained casing pressure, or blowout. For effective cementing, the cement slurry should completely displace the drilling fluid. In practice, this is hard to achieve and some mud is left in the wellbore where it contaminates the cement after cement placement.

This study investigates the effect of mud contamination of cement on the integrity of cement-formation interface. Flow-through experiments were …

An Experimental And Theoretical Critique Of Flow Model Accuracy, Shannon Ray Chollett

LSU Master's Theses

In today’s exploration and production environment it is required that engineers must collect and use vast amounts of data for flow model construction and calibra- tion, as well as reservoir estimation and optimization. With modern technology, the data volume can be overwhelming. It is necessary that data monitoring and calibration are highly efficient. It is also essential that physical and mathematical models can be tested in repeatable, inexpensive experiments. The experiments described in this thesis will develop and perform verification of algorithms and can generate prior geomodels, collect and process seismic refraction data, collect and process production data, and calibrate …

Simulations Of The Primary Cement Placement In Annular Geometries During Well Completion Using Computational Fluid Dynamics (Cfd), Muhammad Zulqarnain

LSU Master's Theses

Effective zonal isolation during primary cementing is only possible when drilling mud in the annulus is completely displaced with cement, while the spacers aid in this process. During the displacement process the rheological properties of fluids used and the operating conditions control the motion of different fluids interfaces; desired stable interfacial displacement leads to piston like motion. Computational Fluid Dynamics (CFD) tool with the Volume-of-Fluid (VOF) has been validated against experimental and used to conduct numerical experiments in a virtual well model consisting of 50 ft vertical section of 8.765" x 12.5" annulus having initially mud and this mud is …