Other Engineering Science and Materials Commons^™

Mode I Fracture Toughness Of Eight-Harness-Satin Carbon Cloth Weaves For Co-Cured And Post-Bonded Laminates, Josh E. Smith

Master's Theses

Mode I interlaminar fracture of 3k 8-Harness-Satin Carbon cloth, with identical fill and weft yarns, pre-impregnated with Newport 307 resin was investigated through the DCB test (ASTM D5528). Crack propagations along both the fill and weft yarns were considered for both post-bonded (co-bonded) and co-cured laminates. A patent-pending delamination insertion method was compared to the standard Teflon film option to assess its applicability to mode I fracture testing. The Modified Beam Theory, Compliance Calibration method, and Modified Compliance Calibration method were used for comparative purposes for these investigations and to evaluate the validity of the proposed Equivalent Stiffness (EQS) method. …

Structure And Morphology Of Sulfonated Polysulfone And Perfluorosulfonic Acid Ionomers, Chen Wang

Doctoral Dissertations

The limitations of conventional perfluorosulfonic acid (PFSA) based membrane materials have provoked the search for alternative materials which can function as the electrolyte in PEM fuel cells operated at higher temperatures (> 100 °C) and without humidification. A novel class of sulfonated poly(phenylene) sulfone (sPSO2) ionomers have shown much higher proton conductivity than typical PFSA membranes at elevated temperatures. In this dissertation, both computational and experimental methods were used to investigate proton transfer, morphological and structural properties of sPSO2 and PFSA ionomers. We have undertaken ab initio electronic structure calculations to understand the primary hydration and the transfer of protons …

Quantum Dot Deposition Into Pdms And Application Onto A Solar Cell, Christopher Marcus Botros, Richard N. Savage

Master's Theses

Research to increase the efficiency of conventional solar cells is constantly underway. The goal of this work is to increase the efficiency of conventional solar cells by incorporating quantum dot (QD) nanoparticles in the absorption mechanism. The strategy is to have the QDs absorb UV and fluoresce photons in the visible region that are more readily absorbed by the cells. The outcome is that the cells have more visible photons to absorb and have increased power output. The QDs, having a CdSe core and a ZnS shell, were applied to the solar cells as follows. First, the QDs were synthesized …

Calcium Phosphate-Based Resorbable Biomaterials For Bone Regeneration, Daniel O. Costa

Electronic Thesis and Dissertation Repository

Bone defects are a prevalent problem in orthopedics and dentistry. Calcium phosphate-based coatings and nanocomposites offer unique solutions towards producing scaffolds with suitable physical, mechanical and biological properties for bone regeneration.

We developed a novel method to synthesize hydroxyapatite (HA) particles with high aspect ratio using sol-gel chemistry and hydrothermal treatment. We obtained tunable pure-phase carbonated-HA in the form of micro/nanorods and nanowires (diameters 25-800 nm). To mimic the structure of bone, HA nanowires were homogenously mixed within poly(ε-caprolactone) (PCL) to produce nanocomposites with improved mechanical properties as determined by uniaxial tensile testing.

Surface chemistry and topography of biomaterials play …

Laboratory And Field Evaluation Of Two Warm-Mix Additives In Connecticut And Validation Of An Alternative Moisture Susceptibility Test, Alexander K. Bernier

Master's Theses

The first official state Warm-Mix Asphalt (WMA) pavement project in Connecticut was constructed between July 20th and 22nd, 2010 and it involved three experimental sections, i.e. one section with a conventional HMA (control section) and two WMA sections with different technologies, wax and foamed asphalt. All three sections are located on Route 70 in central Connecticut. The materials were collected in loose form and reheated and compacted in laboratory conditions (laboratory fabricated specimens). This paper discusses the effect of mix type on the results from several tests conducted in the laboratory, such as Semi-Circular Bending, Hamburg Wheel Tracking, Indirect Tensile, …

Development Of A Structured Concrete Thermocline Thermal Energy Storage System, Bradley M. Brown

Graduate Theses and Dissertations

The past couple of decades have shown a concern when considering the way the world obtains its power. The focus has been switching from fossil fuels that have been used for hundreds of years to renewable energy sources, such as the sun. Solar energy is readily and infinitely available for harnessing. One problem with solar energy, though, is its inability to be used during the night time and during cloud covered weather. A solution to this problem is the use of energy storage mechanisms. For solar plants that use solar thermal energy (concentrating solar power plants), thermal energy storage (TES) …

Electronic And Magnetic Excitations In Graphene And Magnetic Nano-Ribbons, Maher Zakaria Ahmed Selim

Electronic Thesis and Dissertation Repository

The discovery of graphene - a 2D material with superior physical properties - in 2004 was important for the intensive global research to find alternatives to three-dimensional (3D) semiconductor materials in industry. At the same time there have been exciting advances for 2D magnetic materials on the nanometer scale. The superior properties of graphene are mainly attributed to its crystal structure and its relatively short-range interactions. These properties show that natural and artificial 2D materials are promising for new applications.

In this thesis we have carried out a comprehensive investigation of the effects of the 2D lattice structures, the roles …

Material Reduction In Corrugated Containers For The Fresh Produce Industry, Justin Patterson

Industrial Technology and Packaging

In the fresh produce industry, corrugated containers must be made to provide adequate protection throughout the product life cycle. In response to increasing materials costs in the corrugated industry, companies are focusing upon developing more efficient packaging designs. The scope of this project focuses on presenting alternative corrugated packaging designs for the fresh produce industry. Included are one piece designs, three piece bliss designs and alternative material exploration. This project presents the performance of new solutions by exploring their compressive strength before and after exposure to humidity.

Effect Of Moisture Absorption On The Sinter Quality Of Central Solenoid (Cs) Coil Pack, Zeshaan Sher Mohammed

Masters Theses

Fusion energy has been said to be the solution to all the world’s energy problems. The International Thermonuclear Experimental Reactor (ITER) is the flagship project to demonstrate the feasibility of fusion energy. The Central Solenoid (CS), an important component of the reactor, is needed to induce plasma current, initiate, ramp-up, ramp-down, and sustain plasma in a very controlled manner. In order to achieve this, the CS coil packs must be manufactured under controlled conditions. The CS conductor is an advanced cable-in-conduit Nb3Sn superconductor. The CS cable will be made in long continuous sections but with thousands of meter of cable …

Radiation-Curable Adhesives For Wood Composites, Timothy H. Starr

Masters Theses

Wood composites are widely used in construction applications because of their superior dimensional and structural attributes over raw wood products. However, current wood composite manufacturing practices, which rely on thermal-curing of adhesives, are expensive, energy intensive, time consuming and are prone to manufacturing defects. Use of radiation curable adhesives (RCAs) could potentially answer all of these issues. Specifically, use of electron-beam (e-beam) radiation has been increasing in areas of research and industry where rapid, low-temperature polymerization is required and low energy consumption is desired. For e-beams to be used in wood composites, however, it must be determined whether or not …

A Study Of Irrigation, Fertigation And Plasticulture In Burley Tobacco, With A Focus On Yield, Quality And Tsna Reduction, Eric F. Caldwell

Masters Theses

Nitrogen fertilization is important in attaining high yielding, quality tobacco. However, practices that use excessive N can be uneconomical, threaten the environment and produce leaves that are high in nitrates. Leaves high in nitrates have been positively correlated with leaves that are high in tobacco specific nitrosamines (TSNA), which are considered potent carcinogens. Competition from cheaper, foreign leaf, increasing costs of fertilizers and new market structures which show purchasers seeking low TSNA leaf demand that producers become more efficient in their N use. The objective of this study is an examination of burley (TN 90) and dark (KY 171) tobacco …

Development Of A Methodology To Evaluate Environmental Implications Of Lean Implementation, Pamuk Teparakul

Masters Theses

While much research has confirmed the effectiveness of lean manufacturing in improving manufacturing productivity, far less work has focused on the impact of lean implementation on the different measures of environmental performance. More notably, there remains much to be understood about the complex relationship between lean manufacturing principles and their overall environmental impacts.

The purpose of this research is to develop a multi-phase methodology to assist practitioners in evaluating overall environmental impacts associated with implementation of various lean manufacturing principles. This knowledge would then allow practitioners to design and analyze manufacturing systems for both productivity and environmental concerns. A case …

A Study Of The Flow Characteristics In The Core Region Of The Sandia Engineering Reactor, James A. Moeller

Chemical and Biological Engineering ETDs

The core region of a nuclear rector is an extremely compact area with a capability of providing a very high heat output. Regardless of the type of coolant used, the heat transfer characteristics of this region must be adequately designed to prevent any undesirable "hot-spots" from developing. The Sandia Engineering Reactor has one of the most compact cores of any in currently operating nuclear reactors. For this reason it is necessary to investigate fully the heat transfer characteristics of the core. The rate of heat transfer from the fuel elements to the coolant is directly dependent upon the temperature difference …