Engineering Science and Materials Commons^™

Combining Modified Atmosphere Packaging And Nisin To Extend The Shelf Life Of Atlantic Salmon (Salmo Salar), Dong Han

All Theses

Atlantic salmon is often used in laboratory experiments to represent marine fishes. Many researchers try to optimize the levels and dosage of preservatives to maintain the freshness and extend the shelf-life of Atlantic salmon. Little information has been provided about the effectiveness of combined method between MAP and nisin, especially on the preservation of Atlantic salmon. Strong evidences suggest that MAP associated with nisin may have a potential to improve Atlantic salmon storage quality. Preservation effectiveness of combining modified atmosphere package (MAP) and nisin on fresh Atlantic salmon was determined using various methods. Six groups of farmed Atlantic salmon were ...

Microanalysis Of Polymer Chain Diffusion In Heat Seals, Russell Cooper

All Theses

Heat sealing is an integral method for the closure and protection of packaging. Previous work has shown that seal strength is developed by the interdiffusion of polymer chains within heat seals. Heat seals were made between two dissimilar materials. Poly(ethylene-co-acrylic acid) (EAA) was heat sealed to ionomer. Diffusion within the EAA-ionomer heat seals was estimated. The diffusion estimates were then related to resulting seal strength in the EAA-ionomer sealant system. Heated tooling sealing was utilized to make heat seals at 40 psi (275.79 kPa), 0.5 seconds, and a range of temperatures between 180˚F (82.22˚C ...

The Effects Of Chlorine Dioxide Gas On The Sensory Properties Of Whole Tomatoes, Christopher Gottilla

All Theses

This experiment sought to measure the changes in sensory quality that occur in tomatoes as the result of chlorine dioxide gas treatment. Tasti-Lee tomatoes (VFFF Hybrid #5755) were treated with two different levels of chlorine dioxide gas (10mg and 50mg of ClO2-forming material per kg of tomato) utilizing sachets. Testing compared the treated tomatoes and an untreated control group. These tests included flat-plate compression for firmness, sensory evaluation using a difference from control test, color analysis of the skin and flesh using a colorimeter, and enumeration of aerobic microbes and yeasts and molds. Flat-plate compression of whole tomatoes revealed no ...

Effects Of Transportation Hazards On Package Performance And Food Product Shelf Life, Kyle Dunno

All Dissertations

This research studied the effect of transportation hazards on food product shelf life and package performance. Studies were conducted to determine the effect of package headspace volume, product viscosity and storage temperature on package integrity. Finally, accelerated shelf life testing (ASLT) was utilized to determine how simulated transportation hazards affected the shelf life of a specific food product. Institutional retort pouches containing either water or 5% starch solution were filled with varying amounts of headspace volume to determine if package headspace volume could aid in package performance during simulated engineering tests for packaged products. Fixed displacement vibration testing and compression ...

Customizing Fiber Spinning Approaches For Polymer/Nano-Carbon Composites, Kenan Song

Mechanical Engineering Dissertations

Among the many potential applications of nano-carbon (nC), their ability to improve stiffening, strengthening, and toughening mechanisms in polymeric materials has been given considerable attention due to the excellent mechanical properties, and low density of these graphitic materials. The approaches toward designing composites have provided numerous opportunities for the invention of new materials for applications requiring high-strength and high-modulus. Precise control of processing factors including (i) preserving intact nC structure, (ii) uniform dispersion of the nC in polymers, (iii) effective filler-matrix interfacial interactions, and (iv) alignment/orientation of the nC and/or polymer chains all can contribute to the superior ...

Inżynieria Chemiczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Computational Study Of Microstructure-Propertymechanism Relations In Ferroic Composites, Fengde D. Ma

Dissertations, Master's Theses and Master's Reports - Open

Ferroic materials, as notable members of smart materials, have been widely used in applications that perform sensing, actuation and control. The macroscopic property change of ferroic materials may become remarkably large during ferroic phase transition, leading to the fact that the macroscopic properties can be tuned by carefully applying a suitable external field (electric, magnetic, stress). To obtain an enhancement in physical and/or mechanical properties, different kinds of ferroic composites have been fabricated. The properties of a ferroic composite are determined not only by the properties and relative amounts of the constituent phases, but also by the microstructure of ...

Effects Of Operating Conditions On Removal Of Trace-Amount Testosterone By Nitrocellulose Filter Membrane, Ying Liang

Environmental Engineering Theses and Graduate Student Research

Hormone can be removed by membrane filtration via membrane interception, sorption and diffusion. However, the effects of operating conditions of membrane filtration on hormone removal have not been evaluated systematically. In this study, the removal of testosterone by nitrocellulose membranes under different operating conditions (e.g., initial testosterone concentrations, sample volumes, flow rates and membrane pore sizes) was investigated. ¹⁴C-labeled testosterone was used as a tracer to determine the removal of testosterone in the filtration process, and a hydrodynamic model was used to determine dispersion coefficient (D) associated with the operating conditions and radius of hormone molecule. Results indicate ...

Uv Laser-Assisted Diamond Deposition, Mengxiao Wang

Electrical Engineering Theses and Dissertations

Diamond, due to its unique properties, has been studied for decades. Many diamond synthesis methods have been developed as well. As one of the synthesis methods, combustion flame chemical vapor deposition (CVD) is considered as the most flexible way. Combined with laser irradiation, laser-assisted combustion flame CVD can enhance the deposition process of diamond films. In this thesis work, efforts were made to explore the capability of a laser-assisted combustion flame CVD technique with krypton fluoride (KrF) excimer laser irradiation for improving diamond thin film quality and deposition rate. The research efforts mainly focus on following activities, including: 1) studying ...

Field Monitoring Of Rail Squats Using 3d Ultrasonic Mapping Technique, Sakdirat Kaewunruen, Makoto Ishida

Sakdirat Kaewunruen

Rail squats and studs are typically classified as the propagation of any cracks that have grown longitudinally through the subsurface. Some of the cracks could propagate to the bottom of rails transversely, which have branched from the initial longitudinal cracks with a depression of rail surface. The rail defects are commonly referred to as ‘squats’ when they were initiated from damage layer caused by rolling contact fatigue, and as ‘studs’ when they were associated with white etching layer caused by the transform from pearlitic steel due to friction heat generated by wheel sliding or excessive traction. Such above-mentioned rail defects ...

Synthesis, Fabrication And Characterization Of Magnetic And Dielectric Nanoparticles And Nanocomposite Films, Xiaohua Liu

Dissertations and Theses, 2014-Present

Materials science is an interdisciplinary field investigating the structure-property relationship in solid-state materials scientifically and technologically. Nanoscience is concerned with the distinctive properties that matter exhibits when confined to physical dimensions on the order of 10^-9 meters. At these length scales, behaviors of particles or elaborate structures are often governed by the rules of quantum mechanics in addition to the physical properties associated with the bulk material.

The work reported here seeks to employ nanocystals, binary nanocomposites and thin films of materials, to build versatile, functional systems and devices. With a focus on dielectric, ferroelectric, and magnetoelectric performance, a ...

Characterization Of Wide Band Gap Semiconductors And Multiferroic Materials, Bo Cai

Dissertations and Theses, 2014-Present

Structural, optical and electrical properties of zinc oxide (ZnO), aluminum nitride (AlN), and lutetium ferrite (LuFe₂O4) have been investigated. Temperature dependent Hall Effect measurements were performed between 80 and 800 K for phosphorus (P) and arsenic (As) doped ZnO thin films grown on c-plane sapphire substrate by RF magnetron sputtering. These samples exhibited n-type conductivity throughout the temperature range with carrier concentration of 3.85 × 10 ¹⁶ cm^-3 and 3.65 × 10 ¹⁷ cm^-3 at room temperature for P-doped and As-doped ZnO films, respectively. The Arrhenius plots of free electron concentration of those doped samples showed ...

Synthesis And Evaluation Of Sensitizer Drug Photorelease Chemistry: Micro-Optic Method Applied To Singlet Oxygen Generation And Drug Delivery, Goutam Ghosh

Dissertations and Theses, 2014-Present

This thesis summarizes a new micro-optic method for singlet oxygen generation and sensitizer drug delivery, which include i) synthesis and evaluation of a first generation device for drug delivery from native and fluorinated silica probe tips, ii) synthesis of PEG conjugated sensitizers to study phototoxicity in ovarian cancer cells, and iii) synthesis and evaluation of tris-PEGylated chlorin conjugated fluorinated silica for its future integration into the device to use as a 2nd generation device. A first generation micro-optic device was developed that works by sparging O2 gas and light generating cytotoxic singlet oxygen that cleaves the covalently attached drug (sensitizer ...

The Effect Of Fixation Plate Length On Spinal Instability Following Anterior Cervical Plate Fixation For The Repair Of In Vitro Flexion-Distraction Injuries, Abdulaziz J. Al-Kuwari

University of Western Ontario - Electronic Thesis and Dissertation Repository

Abstract:

The Effect of Fixation Plate Length on Spinal Instability Following Anterior Cervical Plate Fixation for the Repair of in Vitro Flexion-Distraction Injuries

Introduction: Anterior cervical decompression and fusion with a plate (ACDFP) is a commonly performed treatment following a traumatic injury to the subaxial cervical spine. The purpose of the presented work was to determine the biomechanical effect of plate length on cervical spine kinematic stability following ACDFP stabilization for a simulated traumatic injury.

Methods: Eleven fresh-frozen cadaveric C5-C6 and C6-C7 motion segments were examined in this study. To assess kinematics, flexibility testing was performed on each specimen using ...

Size-Dependent Electroelastic Properties Of Piezoelectric Nanoplates, Zhengrong Zhang

University of Western Ontario - Electronic Thesis and Dissertation Repository

With the development of nanotechnology, piezoelectric nanostructures have attracted a surge of interests in research communities for the potential applications as transistors, sensors, actuators, resonators and energy harvesters in nanoelectromechanical systems (NEMS) due to their high electromechanical coupling and unique features at the nano-scale. Piezoelectric nanomaterials have been characterized to possess size-dependent electromechanical coupling properties from both experimental and theoretical perspectives. Therefore it is of great importance to investigate the physical mechanisms of these distinct nano-scale structure features in order to fulfill the design and application of those piezoelectricity-based nanodevices.

Due to large surface to volume ratio and manifest strain ...

Micromechanics Modeling Of The Electrical Conductivity Of Carbon Nanotude (Cnt)- Polymer Nanocomposites, Chuang Feng

University of Western Ontario - Electronic Thesis and Dissertation Repository

The addition of carbon nanotubes (CNTs) in polymers to form conductive composites has been attracting great interest from research and industry communities due to their potential applications. Experiments and simulations have demonstrated that the addition of a very small amount of CNTs into polymers can significantly improve the electrical conductivity of the composites. Such significant improvement in the electrical conductivity is attributed to two conductivity mechanisms: nanoscale electron hopping and microscale conductive networks. Understanding and prediction of the overall electrical conductivity of the composites with the incorporation of the conductivity mechanisms that underpin the macroscopic electrical properties are essential for ...

Radiation-Induced Radicals In Polyurea-Crosslinked Silica Aerogel, Benjamin Michael Walters

Masters Theses

Free radicals are atoms or molecules with an odd number of electrons in an outer shell. Since electrons typically occur in pairs, this leaves one electron that is unpaired. In seek of another electron to pair with, free radicals react with and steal electrons from neighboring molecules, which then become free radicals themselves. This can start a chain reaction, cascading into large scale damage.

Ionizing radiation can tear through molecules, just as bullets can tear through things that we see. If free radicals can be detected, and seen to increase in a material upon radiation exposure, this can indicate molecular ...

Analytical And Experimental Analysis Of Magnetorheological Elastomers, Sarah Trabia

UNLV Theses/Dissertations/Professional Papers/Capstones

Many engineering applications ranging from robotic joints to shock and vibration mitigation can benefit by incorporating components with variable stiffness. In addition, variable stiffness structures can provide haptic feedback (the sense of touch) to the user. In this work, it is proposed to study Magnetorheological Elastomers (MRE), where iron particles within the elastomer compound develop a dipole interaction energy, to be used in a device for haptic feedback. A novel feature of this MRE device is to introduce a field-induced variable shear modulus bias via a permanent magnet and using a current input to the electromagnetic control coil to change ...

Surface Hardness Of Friction Stir Welded Aa6063 Pipe, Azman Ismail, Mokhtar Awang

AZMAN ISMAIL

The external surface hardness of friction stir welded aluminum alloy 6063 pipe joint was investigated in this paper. The 89mm of outside diameter pipe with 5mm of wall thickness was used as test pipe piece for this experiment on closed butt joint configuration by utilising Bridgeport 2216 CNC milling machine and orbital clamping unit specially designed to cater for this task and function. Several welded samples were produced on varying process parameters which were successfully joined by using a non-consumable tool with a flat shoulder and a cylindrical pin.

Surface Hardness Of Friction Stir Welded Aa6063 Pipe, Azman Ismail, Mokhtar Awang

Azman Ismail

The external surface hardness of friction stir welded aluminum alloy 6063 pipe joint was investigated in this paper. The 89mm of outside diameter pipe with 5mm of wall thickness was used as test pipe piece for this experiment on closed butt joint configuration by utilising Bridgeport 2216 CNC milling machine and orbital clamping unit specially designed to cater for this task and function. Several welded samples were produced on varying process parameters which were successfully joined by using a non-consumable tool with a flat shoulder and a cylindrical pin.