Engineering Science and Materials Commons^™

Degradation And Water Quality Dynamics Of Sugarcane Residue In South Louisiana, Jose Roberto Deras

LSU Doctoral Dissertations

PURPOSE: This research was conducted to assess methods to manage the residue blanket to avoid open field burning in sugarcane. Experiments were conducted in the state of Louisiana to evaluate methods to asses and potentially reduce water quality issues. METHODS: Concentrations and frequencies of biological compost tea were sprayed on sugarcane combine-harvester residue blanket to increase degradation rate and reduce potential for runoff water to transport nutrients and sediments that may impair water bodies, while sustaining suitable sugarcane yield. Carbon dioxide evolution rate (mg CO2-C) and CO2 fluxes were measured in laboratory and in open field conditions; as an index …

Stereolithography Of Poly(Ethylene Glycol) Hydrogels With Application In Tissue Engineering As Peripheral Nerve Regeneration Scaffolds, Karina Arcaute

Open Access Theses & Dissertations

In recent years, rapid prototyping (RP) technologies initially developed to create prototypes prior to production for the automotive, aerospace, and other industries, have found applications in tissue engineering (TE). Several different RP technologies are being used to fabricate biocompatible 3D structures with controlled micro- and macro-scale characteristics. The focus of this research was to explore the capabilities of the RP technology, stereolithography (SL), for creating complex, 3D scaffolds with applications in TE using a photocrosslinkable biopolymer, poly(ethylene glycol) (PEG). The primary objective was to create an implantable multi-lumen nerve guidance conduit (NGC) for the regeneration of peripheral nerves.

Studies of …

A Study Of The Interaction Of Thioindigo Dye, With Several Inorganic Host Materials, Alejandra Ramirez

Open Access Theses & Dissertations

Maya Blue has been the focus of numerous studies and is believed to be a mixture of palygorskite clay and indigo dye.^1,2 Several derivatives of this pigment have been developed with intriguing properties. For instance, the dye thioindigo reacts with the palygorskite clay to exhibit a broad range of colors from red to blue under UV-Vis excitation. Based on FT-Raman and computer simulation, previous work performed in our group could relate indigo and thioindigo interaction to the aluminum sites in the framework. super>3,4

The work performed with other inorganic host materials such as, layer structures and zeolites have …

Elevated Temperature Oxidation Of Boron Modified Ti-6al-4v, Deborah May-Katherine Sweeney

Browse all Theses and Dissertations

The addition of trace amounts (~0.1 wt%) of boron to titanium alloys refines theas-cast grain size by an order of magnitude from 2000μm to 200μm. The reduced grain size has potentially beneficial effects on the processibility of titanium alloys. Reports also indicate that the room temperature corrosion resistance of the boron containing alloys may be substantially greater than conventional titanium alloys. In this study, the effects of boron addition on oxidation resistance are investigated, since conventional titanium alloys have limited corrosion resistance in air above 650°C. The mass gain per unit surface area was measured during elevated temperatures exposed to …

A Finite Element Study Of Piezoelectric Thin Films On Substrates, Bo Liu

Theses and Dissertations

The overall goal of this work has been mainly to advance the understanding of the degradation in the response of piezoelectric thin films after they are deposited on substrates. To have better understanding of the difference in the response between free standing piezoelectric films and those deposited on a substrate, we calculated the normalized "effective" piezoelectric coefficients for BT/MgO, PZT/STO and ZnO/STO respectively. We also studied the impact on the effective coefficients due to the components of the bulk material's piezoelectric coefficients. After studying the clamping effects of the substrate, lattice mismatch, stiffness of the films and the substrates, we …

A Study Of Regret And Rejoicing And A New Mcdm Method Based On Them, Xiaoting Wang

LSU Doctoral Dissertations

Multi-criteria decision-making (MCDM) is one of the most widely used decision methodologies in the sciences, business, and engineering worlds. MCDM methods aim at improving the quality of decisions by making the process more explicit, rational, and efficient. One controversial problem is that some well-known MCDM methods, like the additive AHP methods and the ELECTRE II and III methods, may cause some types of rank reversal problems. Rank reversal means that the ranking between two alternatives might be reversed after some variation occurs to the decision problem, like adding a new alternative, dropping an old alternative or replacing a non-optimal alternative …

Moderately-Rapid Assessment Of Alkaline Desiccation Environmental Systems, David Alan Bates

LSU Doctoral Dissertations

A moderately-rapid assessment tool was developed to analyze the waterless desiccation compost toilet investigated in a rural Mexican setting. Over 100 social factors were identified along with the applicable technical factors that influenced the low acceptability of the toilets. A 4-point rating scale was developed to increase the ability and speed of analyzing both the social and technical data. The treatment process was an alkaline-desiccation process with mean pH values of 8.2 ± sd 1.1 and water content of 18.3% ± sd 9.9, which resulted in mean fecal coliform values of 15.0 MPN/g ± sd 31.8, drastically lower than the …

Stochastic Demand Forecast And Inventory Management Of A Seasonal Product A Supply Chain System, Mohammad Anwar Ashek Rahman

LSU Doctoral Dissertations

Estimation of seasonal demand prior to an active demand season is essential in supply chain management. The business cycle of the seasonal demand is divided into two stages: stage-1, the slow-demand period, and stage-2, the peak-demand period. The focus here is to determine an appropriate demand forecast for the peak-demand period. In the first set of forecasting model, a standard gamma and an inverse gamma prior distribution are used to forecast demand. The parameters of the prior model are estimated and updated based on current observation using Bayesian technique. The forecasts are derived for both complete and incomplete datasets. The …

Internal Cooling In Ribbed Rectangular (Ar=4:1) Passages At High Rotation Numbers And Improvement In Finning Strategies, Fuguo Zhou

LSU Doctoral Dissertations

Experimental studies have been performed on two-pass rectangular internal coolant channels with aspect ratio AR 4:1 with high rotation numbers. Three passages are investigated: smooth, 90 deg ribbed and 45 deg ribbed. A maximum Reynolds number of 150,000 and a maximum rotation number of 0.6 are achieved in the study. These maximum parameter values are considerably higher than those previously reported for the 4:1 AR geometry, and provide data for parameter ranges that may be representative of certain modern turbine blades. Heat transfer behaviors with rotation in the three passages are presented. Rotation effects, density effects and buoyancy effects are …

Numerical Modeling Of Continuous Flow Microwave Heating - Coupling Of High Frequency Electromagnetism With Fluid Flow And Heat Transfer, Deepti Salvi

LSU Doctoral Dissertations

This study focused on numerical and experimental investigation of continuous flow microwave heating. A numerical model was developed to predict the temperature of a liquid product heated in a continuous-flow focused microwave system by coupling electromagnetism, fluid flow, and heat transfer in two different software packages (ANSYS Multiphysics 9.0 and COMSOL Multiphysics 3.4). The temperature and energy distributions simulated in ANSYS were verified against other numerical studies published in the literature. Comparison of the simulated temperature in ANSYS with experimental data for salt water of two different salinities showed good agreement. To simulate the experimental conditions more accurately, a comprehensive …

Cost Model For A Small Glass Manufacturing Enterprise, Swetha Gopisetti

Graduate Theses, Dissertations, and Problem Reports (ETD)

The cost model developed is for small, glass-manufacturing enterprises to help them determine their product costs. It estimates the direct cost in glass manufacturing such as material, labor and energy costs. The overhead costs were based on AACE recommended practices to determine product cost and selling price. The model was tested to estimate the costs in glass marble manufacturing. It determines the unit material cost of the product based on material mix ratio and material costs. The energy costs for the product were based on the batch processing time and gas consumption rate. The model was analyzed to predict variations …

A Unified Methodology Of Maintenance Management For Repairable Systems Based On Optimal Stopping Theory, Hongye Wang

LSU Doctoral Dissertations

This dissertation focuses on the study of maintenance management for repairable systems based on optimal stopping theory. From reliability engineering’s point of view, all systems are subject to deterioration with age and usage. System deterioration can take various forms, including wear, fatigue, fracture, cracking, breaking, corrosion, erosion and instability, any of which may ultimately cause the system to fail to perform its required function. Consequently, controlling system deterioration through maintenance and thus controlling the risk of system failure becomes beneficial or even necessary. Decision makers constantly face two fundamental problems with respect to system maintenance. One is whether or when …