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Full-Text Articles in Engineering

Development Of A Compression Test Device For Investigating Interaction Between Diffusion Of Biodiesel And Large Deformation In Rubber Dec 2011

Development Of A Compression Test Device For Investigating Interaction Between Diffusion Of Biodiesel And Large Deformation In Rubber

A.S. Md Abdul Haseeb

Motivated by environmental and economic factors, biodiesel has been introduced to partially replace the diminishing stock of petroleum-based fuel. However, the use of biodiesel such as palm biodiesel is placing additional demands on automotive components, e.g. rubber components, due to a compatibility issue in the fuel system. In engineering applications where hostile environments are involved, the long-term mechanical response of rubber components is affected by interactions existed between diffusion of liquids into the material and fluctuating multiaxial loading. Hence, it is crucial to investigate the durability of rubber components in this aggressive environment. A number of studies on static immersion …


Reconsideration For A Study Of The Effect Of Chloride Binding On Service Life Predictions, Ming-Te Liang, Ran Huang, Hao-Yuan Jheng Oct 2011

Reconsideration For A Study Of The Effect Of Chloride Binding On Service Life Predictions, Ming-Te Liang, Ran Huang, Hao-Yuan Jheng

Journal of Marine Science and Technology

The major purpose of this paper is to use Kirchhoff's transformation associated with Laplace's transformation methods to obtain the analytical solution of the modified Fick's second law of nonlinear diffusion equation with initial and boundary conditions provided by Martín-Pérez et al. [A study of the effect of chloride binding on service life predictions. Cement and Concrete Research 2000; 30 (8): 1215-1223]. Based on experimented data and four kinds of chloride binding isotherm, i.e., no, linear, Langmuir, and Freundlich binding, results of free and total chloride concentration profiles calculated from the analytical solution are presented for a concrete structure suffered from …


Computational Studies Of Ion Transport In Polymer Electrolytes, Hui Wu Oct 2011

Computational Studies Of Ion Transport In Polymer Electrolytes, Hui Wu

Doctoral Dissertations

Improving ionic conductivity and lithium mobility in polymer electrolytes is important for their practical use for battery electrolytes. In this study, a combination of molecular dynamics and Monte Carlo simulations was used to bring insight into lithium ion transport in poly(ethylene oxide) (PEO) with plasticizers and also next to alumina solid surface doped with lithium salt. The simulations were performed using a moderately high molecular weight polymer (Mn = 10,000 g/mol) at an EO:Li ratio of 15. For the plasticized system, the PEO with LiN(CF3SO 2)2 (LiTFSI) was mixed with 10 wt% plasticizers that included either cyclic ethylene carbonate …


Em Stimulation Of Water For Geotechnical Applications, Harlan Dwight Olson Sangrey May 2011

Em Stimulation Of Water For Geotechnical Applications, Harlan Dwight Olson Sangrey

Boise State University Theses and Dissertations

The task of cleaning soil and/or groundwater contaminated by leakage from aging underground gasoline or petrochemical tanks along with surface spills of gasoline and other hazardous chemicals is of utmost importance for federal and state environmental agencies. Traditional clean up and contaminant removal involves dig-and-treat methods that are costly and impractical for large, contaminated sites. Less disruptive remediation techniques, such as air sparging, have become more attractive in the past decade. Air sparging, bioventing, and other remediation technologies that use air injection into soil can become very effective for non-aqueous phase liquid (NAPL) removal using volatilization and bioremediation. However, the …


Penetration Lag Of Chloride Diffusion Through Concrete Plate Based On Advancing Model, Chih-Hsing Wang, Cho-Liang Tsai, Ching-Chang Lin Apr 2011

Penetration Lag Of Chloride Diffusion Through Concrete Plate Based On Advancing Model, Chih-Hsing Wang, Cho-Liang Tsai, Ching-Chang Lin

Journal of Marine Science and Technology

The solution, based on Neumann's theory, for the content distribution of a diffusion material in a semi-infinite medium is applicable for the case in which a diffusion material diffuses from one side of a plate medium to the other side. After the diffusion material reaches the other side, the penetration rate of the diffusion material is solved using Fick's diffusion law. In this study, concrete plates are manufactured and submerged individually in special containers with saltwater on one side and freshwater on the other side, and no electric charge is applied. The amount of chloride penetrating the plate is monitored. …


Co2 Diffusion Through Gelatin Experiment, Jennifer Welborn Jan 2011

Co2 Diffusion Through Gelatin Experiment, Jennifer Welborn

STEM Digital

An example of measuring lengths.


Impurity And Interdiffusion In The Magnesium-Aluminum System, Sarah Tiffany Brennan Jan 2011

Impurity And Interdiffusion In The Magnesium-Aluminum System, Sarah Tiffany Brennan

Electronic Theses and Dissertations

Magnesium alloys offer a base of lightweight engineering materials for electronic, military and transportation applications where weight reduction is crucial for higher efficiency. Understanding fundamental diffusion behavior in Mg alloys elicits better materials properties through the optimization of processing techniques and heat treatments, whose material responses are affected by diffusion. The main objective of this study is to provide a clear, comprehensive description of the diffusion behavior in the technically important magnesium-aluminum binary metallic system. In this study, diffusion in the Mg-Al system was observed through solid diffusion couples and thin film specimens in the temperature range of 673-523K. The …


One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell Jan 2011

One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell

ETD Archive

The flow of nutrients through any biological tissue is important to maintain homeostasis. If the transport process is understood, medical research teams can better design medications, prosthetic implants, and tissue scaffolds. Additionally, transport rates help physicians to better understand disease states and wound healing, including minor injuries such as breaks and sprains, which will aid in better diagnoses. We developed a novel method that measures the rate of diffusion in vitro, of fluorescein sodium salt. Samples were incubated at 37°C in a 5 CO2 atmosphere for various periods of time. Samples were sliced and analyzed using Image-Pro Plus and MATLAB …


Investigations Of Anatomical Connectivity In The Internal Capsule Of Macaques With Diffusion Magnetic Resonance Imaging, Kyle Andrew Ignatius Taljan Jan 2011

Investigations Of Anatomical Connectivity In The Internal Capsule Of Macaques With Diffusion Magnetic Resonance Imaging, Kyle Andrew Ignatius Taljan

ETD Archive

Understanding anatomical connectivity is crucial for improving outcomes of deep brain stimulation surgery. Tractography is a promising method for noninvasively investigating anatomical connectivity, but connections between subcortical regions have not been closely examined by this method. As many connections to subcortical regions converge at the internal capsule (IC), we investigate the connectivity through the IC to three subcortical nuclei (caudate, lentiform nucleus, and thalamus) in 6 macaques. We show that a statistical correction for a known distance-related artifact in tractography results in large changes in connectivity patterns. Our results suggest that care should be taken in using tractography to assess …


Evaporation Of Sessile Drops Under Combined Diffusion And Natural Convection, Peter Kelly-Zion, Christopher J. Purcell, Sawan Vaidya, Jaskirat Batra Jan 2011

Evaporation Of Sessile Drops Under Combined Diffusion And Natural Convection, Peter Kelly-Zion, Christopher J. Purcell, Sawan Vaidya, Jaskirat Batra

Engineering Faculty Research

Experiments were conducted to investigate the range of applicability of a commonly used assumption for evaporation models of sessile drops, that the transport mechanism that controls the evaporation is vapor diffusion. The evaporation rates of sessile drops of 3-methylpentane, hexane, cyclohexane, and heptane were measured. The radius of the drop contact line was constant during the measurements and drops of radius from 1 mm to 22 mm were studied. It was found that a diffusion-controlled evaporation model underpredicts the evaporation rate from 36% to 80% depending on the drop size. The increase in the evaporation rate was attributed to a …


Modeling Small Molecule Elution From A Hydrogel Using A Microfluidic Technique, Stephanie Evans Jan 2011

Modeling Small Molecule Elution From A Hydrogel Using A Microfluidic Technique, Stephanie Evans

Master’s Theses

Drug release from a fluid-contacting biomaterial is simulated using a microfluidic device with channels defined by solute-loaded hydrogel. In order to mimic a drug delivery device, a solution of poly(ethylene glycol) diacrylate (PEG-DA), solute, and photoinitiator is cured inside a microfluidic device with a channel through the center ofthe hydrogel. As water is pumped through the channel, solute diffuses out of the hydrogel and into the water. Channel sizes within the devices range from 300 µm to 1000 µm to simulate vessels within the body. The properties of the PEG hydrogel were characterizedby the extent of crosslinking, the swelling ratio, …


In-Field Jc Improvement By Oxygen-Free Pyrene Gas Diffusion Into Highly Dense Mgb2 Superconductor, Minoru Maeda, Jung Ho Kim, Y Zhao, Yoon-Uk Heo, K Takase, Y Kubota, C Moriyoshi, F Yoshida, Y Kuroiwa, S X. Dou Jan 2011

In-Field Jc Improvement By Oxygen-Free Pyrene Gas Diffusion Into Highly Dense Mgb2 Superconductor, Minoru Maeda, Jung Ho Kim, Y Zhao, Yoon-Uk Heo, K Takase, Y Kubota, C Moriyoshi, F Yoshida, Y Kuroiwa, S X. Dou

Australian Institute for Innovative Materials - Papers

Oxygen-free pyrene gas as a carbon (C) dopant was delinked and incorporated into highly dense MgB2 structure via a gas phase diffusion method. The technique offers the advantages that molecular C is homogeneously distributed into MgB2 and substituted at the boron sites without any severe deterioration of grain connectivity. The C substitution causes a significant shrinkage of the a-lattice parameter and an increase in the lattice strain, resulting in high disorder. The introduction of structural disorder as a result of C doping leads to a considerable enhancement of the in-field critical current density (Jc) and upper critical …


Position Preference And Diffusion Path Of An Oxygen Ion In Apatite-Type Lanthanum Silicate La9.33si6o26: A Density Functional Study, Ting Liao, Taizo Sasaki, Shigeru Suehara, Ziqi Sun Jan 2011

Position Preference And Diffusion Path Of An Oxygen Ion In Apatite-Type Lanthanum Silicate La9.33si6o26: A Density Functional Study, Ting Liao, Taizo Sasaki, Shigeru Suehara, Ziqi Sun

Australian Institute for Innovative Materials - Papers

Using density functional theory, we investigated the position preference and diffusion mechanisms of interstitial oxygen ions in lanthanum silicate La9.33Si6O26, which is an apatite-structured oxide and a promising candidate electrolyte material for solid oxide fuel cells. The reported lanthanum vacancies were explicitly taken into account by theoretically determining their arrangement with a supercell model. The most stable structures and the formation energies of oxygen interstitials were determined for each charged state. It was found that the double-negatively charged state is stable over a wide range of the Fermi level, and that the excess oxygen …


Novel Film Formation Pathways For Cu2znsnse4 For Solar Cell Applications, Sree Satya Kanth Bendapudi Jan 2011

Novel Film Formation Pathways For Cu2znsnse4 For Solar Cell Applications, Sree Satya Kanth Bendapudi

USF Tampa Graduate Theses and Dissertations

Because of the anticipated high demand for Indium, ongoing growth of CIGS technology may be limited. Kesterite materials, which replace In with a Zn/Sn couple, are thought to be a solution to this issue. However, efficiencies are still below the 10% level, and these materials are proving to be complex. Even determination of the bandgap is not settled because of the occurrence of secondary phases. We use a film growth process, 2SSS, which we believe helps control the formation of secondary phases. Under the right growth conditions we find 1/1 Zn/Sn ratios and XRD signatures for Cu2ZnSnSe4 with no evidence …


Interdiffusion Behavior Of U-Mo Alloys In Contact With Al And Al-Si Alloys, Emmanuel Perez Jan 2011

Interdiffusion Behavior Of U-Mo Alloys In Contact With Al And Al-Si Alloys, Emmanuel Perez

Electronic Theses and Dissertations

http://purl.fcla.edu/fcla/etd/CFE0003747


Single-Particle Model For A Lithium-Ion Cell: Thermal Behavior, Meng Guo, Godfrey Sikha, Ralph E. White Jan 2011

Single-Particle Model For A Lithium-Ion Cell: Thermal Behavior, Meng Guo, Godfrey Sikha, Ralph E. White

Faculty Publications

The single-particle model presented by Santhanagopalan et al. [ J. Power Sources , 156 , 620 (2006)] is extended to include an energy balance. The temperature dependence of the solid phase diffusion coefficient of the lithium in the intercalation particles, the electrochemical reaction rate constants, and the open circuit potentials (OCPs) of the positive and negative electrodes are included in the model. The solution phase polarization is approximated using a nonlinear resistance, which is a function of current and temperature. The model is used to predict the temperature and voltage profiles in a lithium-ion cell during galvanostatic operations. The single-particle …