Complex Fluids Commons^™

Modeling The Effect Thickener Structure Has On The Oil Release Of Grease, Dana Cressman

Williams Honors College, Honors Research Projects

Our hypothesis was that the thickener type and micelle concentration of grease affected its viscoelastic properties. Measurements were made using a TA AR G2 rheometer and calculations were made using TA rheometer analysis software to characterize the viscoelastic response of grease under oscillatory shear and frequency tests. The oscillatory frequency tests determined the critical micelle concentration. The oscillatory stress tests were taken at temperatures from 5 to 65 degrees Celsius to create a master curve based on time temperature superposition of the measurements. The crossover points of G’ and G” on the oscillatory stress tests demonstrated where the grease transitions …

Effects Of Hofmeister Ions On Gelation Of Gelatin And Pluronic Hydrogels, Eric Britton

Williams Honors College, Honors Research Projects

The purpose of the project was to observe the effects of the Hofmeister series of ions on the gelation of gelatin and Pluronic-127 hydrogels. Hydrogels are semi-solid materials that contain a network of joined molecules through intermolecular interactions which are capable of holding water. Gelatin and Pluronic-127 (PF-127) are thermoreversible, physical crosslinked gels. Gelation occurs when temperature, or other driving forces, reduce the polymer chain solubility until a distinct 2-phase system forms. When aqueous ions are present in solution, they exhibit specific ion effects that have either a stabilizing or destabilizing effect on the solubility of proteins and other polymers. …

The Rheology And Roll-To-Roll Processing Of Shear-Thickening Particle Dispersions, Sunilkumar Khandavalli

Doctoral Dissertations

Particle dispersions are ubiquitous in our daily lives ranging from food and pharmaceutical products to inks. There has been great interest in the recent years in formulation of functional inks to fabricate myriad flexible electronic devices through high-throughput roll-to-roll technologies. The formulations often contain several functional additives or rheological modifiers that can affect the microstructure, rheology and processing. Understanding the rheology of formulations is important for tuning the formulation for optimal processing. This thesis presents investigations on the rheology of particle dispersions and their impact on roll-to-roll technologies. Shear-thickening behavior is common in particle dispersions, particularly, concentrated particulate inks. We …

Bubble Dynamics And Bed Expansion For Single-Component And Binary Gas-Solid Fluidization Systems, Bowen Han

Electronic Thesis and Dissertation Repository

Gas-solid fluidized beds are widely used in industrial dry coal preparation to separate waste from coal (still a primarily important energy source worldwide). It is the density difference between coal and the waste that enables the separation. Experiments were carried out in a two dimensional gas-solid fluidized bed. Filtered air at room temperature was used as the fluidizing gas, while magnetite, sand (two types) and FCC catalyst particles belonging to Geldart groups A and B were used as bed particles. Image processing and Matlab were applied for bubble size and velocity measurements. Bubble properties and bed expansion in fluidized beds …

Ion Size Effects On The Properties Of Charge Regulating Electric Double Layers, Divya Jyoti Prakash

Nanoscience and Microsystems ETDs

The behavior of charged interfaces formed in various systems like colloidal solution, fuel cells, battery, electro-deposition, catalysis is governed by the properties of electrical double layer(EDL). Civilized model with charge regulation boundary condition determined by thermodynamic equilibrium at the interface has been used to model electrical double layer and shows that size of the solvent plays a critical role in characterizing the properties of EDL using classical density functional theory.This thesis investigates the impact of ion size in electrolyte solutions on the electrical double layer formed at the interface using a similar model. It is found that ion size greatly …

Experimental Analysis Of R134a, R22, And R404 For An Edibon Taab: Air Conditioning Lab Unit, Kyle T. Heesen

Senior Honors Projects, 2010-2019

This paper presents an experimental analysis of an Ebidon® TAABTM: Air Conditioning Lab unit running on R-134a being compared with R22 and R404 refrigerants, a $24,449 piece of equipment purchased by the JMU ISAT Department. In this paper we will compare the performance of the R-134a refrigerant under a range of working conditions and compare them to how the system would run on R22 or R404. The experimental tests use varying fan speeds and the R-134a data collected is compared to simulated data collected for R22 and R404. Analysis of the collected data and simulated data will be compared on …

Improving Predictive Capabilities Of Classical Cascade Theory For Nonproliferation Analysis, David Allen Vermillion

Doctoral Dissertations

Uranium enrichment finds a direct and indispensable function in both peaceful and nonpeaceful nuclear applications. Today, over 99% of enriched uranium is produced by gas centrifuge technology. With the international dissemination of the Zippe archetypal design in 1960 followed by the widespread illicit centrifuge trafficking efforts of the A.Q. Khan network, traditional barriers to enrichment technologies are no longer as effective as they once were. Consequently, gas centrifuge technology is now regarded as a high-priority nuclear proliferation threat, and the international nonproliferation community seeks new avenues to effectively and efficiently respond to this emergent threat.

Effective response first requires an …

Uranium Sequestration By Ph Manipulation Using Nh3 Injection In The Vadose Zone Of Hanford Site 200 Area, Claudia Cardona

FIU Electronic Theses and Dissertations

Past nuclear weapon production activities have left a significant legacy of uranium (U) contamination in the vadose zone (VZ) of the Department of Energy (DOE) Hanford Site. This U is a source of groundwater (GW) contamination. There is a concern that elevated U concentration would slowly infiltrate through the VZ, reach the GW water table, and then end up in nearby rivers and lakes. Remediation of U-contaminated low moisture content soil is a challenging task considering the VZ depth, where contamination is found between 70 and 100 m below the ground surface, and the formation of highly soluble and stable …

Shear Driven Micro-Fluidic Pump For Cardiovascular Applications, Nihad E. Daidzic

Aviation Department Publications

A valveless shear-driven micro-fluidic pump design (SDMFP) for hemodynamic applications is presented in this work. One of the possible medical and biomedical applications is in-vivo hemodynamic (human blood circulation) support/assist. One or more SDMFPs can be inserted/implanted into vascular lumens in a form of a stent/duct in series and/or in parallel (bypass duct) to support blood circulation in-vivo. A comprehensive review of various micro-pump designs up to about mid 2000’s is given in [1,2]. Many of micropump designs considered are not suitable for in-vivo or even in-vitro medical/biomedical applications.

Operating principles, design, and SDMFP features are given in [3]. A …

Supercritical Fluid Extraction Of Valuable Chemicals: Application Of Microalgae And Pyrolysis Oil As Feedstocks, Osariemen Ogbeide

Electronic Thesis and Dissertation Repository

In this dissertation, pure and modified carbon dioxide were used as non-conventional solvents for the investigation of lutein, chlorophyll a, chlorophyll b extraction from microalgae and for caffeine extraction from the pyrolysis oil of spent coffee grounds. The use of toxic organic solvents in supercritical fluid extraction has propelled research efforts to develop new solvents that are environmentally friendly and provide faster extraction compared to conventional extraction processes. For this reason, phosphatidylethanolamine (PE), a major phospholipid consisting of 14% of the entire soybean lecithin was acetylated with acetic anhydride, providing a surfactant (N-A-PE).

Then, the synthesized N-A-PE was employed as …

Synthesis Of Biopolymer Materials Tailored For Biological Applications, Nathan P. Birch

Doctoral Dissertations

Biopolymers are able to address a wide variety of medical concerns from chronic wounds to stem cell cultivation to antibacterial and antifouling applications. They are non-toxic, biodegradable, and biocompatible, making them ideal candidates for creating green materials for biological applications. In this thesis, we cover the synthesis of two novel materials from the biopolymers, chitosan and pectin. Chitosan is a biocompatible antibacterial polycation and pectin is an anti-inflammatory polyanion with a strong propensity for hydrogen-bonding. The two chitosan:pectin materials, particles and hydrogels, explore some of the structures that can be created by tuning the electrostatic interactions between chitosan and pectin. …

C.V. - Wojciech Budzianowski, Wojciech M. Budzianowski

Wojciech Budzianowski

-

Renewable Energy And Sustainable Development (Resd) Group, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Evaluation Of A Microfluidic Mixer Utilizing Staggered Herringbone Channels: A Computational Fluid Dynamics Approach, Brian Hama

ETD Archive

Microfluidic platforms offer a variety of advantages including improved heat transfer, low working volumes, ease of scale-up, and strong user control on parameters. However, flow within microfluidic channels occurs at low Reynolds numbers, which makes mixing difficult to accomplish. Adding V-shaped ridges to channel walls, a pattern called the staggered herringbone design (SHB), might alleviate this problem by introducing transverse flow patterns that enable enhanced mixing. However, certain factors affecting the SHB mixer’s performance remain largely unexplored.

In this work, a microfluidic mixer utilizing the SHB geometry was developed and characterized using computational fluid dynamics based simulations and complimentary experiments. …

Surface Enabled Lab-On-A-Chip (Loc) Device For Protein Detection And Separation, Zhichao Wang

Dissertations, Master's Theses and Master's Reports

Sensitive and selective chemical/biological detection/analysis for proteins is essential for applications such as disease diagnosis, species phenotype identification, product quality control, and sample examination. Lab-on-a-chip (LOC) device provides advantages of fast analysis, reduced amount of sample requirements, and low cost, to magnificently facilitate protein detection research. Isoelectric focusing (IEF) is a strong and reliable electrophoretic technique capable of discerning proteins from complex mixtures based on the isoelectric point (pI) differences. It has experienced plenty of fruitful developments during previous decades which has given it the capability of performing with highly robust and reproducible analysis. This progress has made IEF devices …

Synthesis And Characterization Of Porous Liquids, Yuanyou Gao

Masters Theses

Porous liquids consisting of modified hollow spheres which are fabricated by surface engineering with suitable corona and canopy species is one of interesting porous liquids reported recently. By taking advantage of the liquid-like polymeric matrices as a separation medium and the empty cavities as a gas transport pathway, porous liquids can function as promising candidates for postcombustion gas separation and thermal insulation purposes. Moreover, this synthetic strategy can be applied to other nanostructure-based porous liquids, facilitating production of porous liquids with specific request. In this thesis, a new member of this type of porous liquid with hollow spheres ranging from …

Plasma Processes And Polymers Third Special Issue On Plasma And Cancer, Mounir Laroussi, Annemie Bogaerts, Nazir Barekzi

Electrical & Computer Engineering Faculty Publications

(First paragraph) This issue of Plasma Processes and Polymers is the third in a series on the applications of low temperature plasma (LTP) against cancer, or “plasma oncology.” The papers in this issue are inspired from the talks given at the third International Workshop on Plasma for Cancer Treatment (IWPCT) which took place on April 11–12, 2016 in Washington, DC, USA. IWPCT is an international workshop that was created in 2014 as a venue to share cutting edge plasma oncology research. The first IWPCT was held in Washington DC, under the co-chairmanship of Prof. Mounir Laroussi (Old Dominion University) and …

Determination Of Aqueous Surfactant Solution Surface Tensions With A Surface Tensiometer, Remelisa Esteves, Birce Dikici Ph.D, Matthew Lehman, Qayyum Mazumder, Nonso Onukwuba

Beyond: Undergraduate Research Journal

Surfactant solutions are applicable to engineering systems for cooling equipment for electronics. Surfactants can be added to water to improve heat transfer. An application of using aqueous surfactant solutions can be through microchannel heat sink. Although it is ideal to redesign these systems to reduce heat, it is a costly method. Surfactant solutions at optimal solution concentration can be able to transfer heat quickly and effectively with minimum expense. The surface tension of surfactant solutions is an important parameter for boiling heat transfer and must be taken into consideration. The purpose of this research is to measure surface tension of …

Determination Of Surfactant Solution Viscosities With A Rotational Viscometer, Remelisa Esteves, Nonso Onukwuba, Birce Dikici Ph.D

Beyond: Undergraduate Research Journal

Aqueous surfactant solutions are used in engineering systems for improving boiling heat transfer. The purpose of this research is to determine the viscosities of surfactant solutions and to investigate the effect of composition on viscosity. The results obtained can possibly be used as reference for further study in the effects of surfactant solution viscosities on nucleate boiling. A rotational viscometer was used to determine the viscosities of three surfactant solutions – SLS, EH-14, and SA-9 – of various compositions at room temperature. It was discovered that the viscosities of SLS, EH-14, and SA-9 had a nearly consistent pattern as their …

Numerical Simulation On The Combustion Characteristic Of Iron Ore Sintering With Flue Gas Recirculation, Gan Wang, Zhi Wen, Guofeng Lou, Ruifeng Dou, Xunliang Liu, Fuyong Su, Sizong Zhang

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.