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Full-Text Articles in Engineering

Biohydrogen Production By The Hyperthermophilic Bacterium Thermotoga Neapolitana, Xiaohui Yu Dec 2007

Biohydrogen Production By The Hyperthermophilic Bacterium Thermotoga Neapolitana, Xiaohui Yu

All Dissertations

ABSTRACT Thermotoga neapolitana can use different sources of carbon and nitrogen for growth and produces biological hydrogen. Sources of carbon (glucose, sucrose, xylose, xylan, cellulose, cellobiose, starch, corn starch, beet bulp pellet, and rice flour) and nitrogen (yeast extract, fish meal, cottonseed meal, canola meal, linseed meal, and soybean meal) were compared. In the carbon studies, glucose, sucrose, rice flour, and xylan produced similar levels of hydrogen. In the nitrogen studies, Trypticase combined with alternative nitrogen sources can efficiently increases the yield of hydrogen produced by Thermotoga neapolitana. Yeast extract with trypticase as the dual nitrogen sources produced significantly increased …


A Comparison Of Optimized Nonlinear Time History Analysis And The Equivalent Lateral Forces Method For Brace Design, Lukas Balling Aug 2007

A Comparison Of Optimized Nonlinear Time History Analysis And The Equivalent Lateral Forces Method For Brace Design, Lukas Balling

Theses and Dissertations

This thesis presents the development of a design procedure for buckling-restrained braced frames (BRBF's). This procedure uses nonlinear time history analysis and a formal optimization algorithm. The time history analysis includes an elasto-plastic model for the braces. The optimization algorithm is a genetic algorithm. This procedure is referred to throughout the thesis as the "Nonlinear Time History Analysis Procedure with Optimization" (NTHO). Current design specifications for BRBF's are based on inelastic design spectra and approximate formulas for the determination of natural period. These spectra are used to obtain seismic base shear, and the distribution of equivalent lateral forces. Yielding and …


Autonomic Product Development Process Automation, John E. Daley Jul 2007

Autonomic Product Development Process Automation, John E. Daley

Theses and Dissertations

Market globalization and mass customization requirements are forcing companies towards automation of their product development processes. Many task-specific software solutions provide localized automation. Coordinating these local solutions to automate higher-level processes requires significant software maintenance costs due to the incompatibility of the software tools and the dynamic nature of the product development environment. Current automation methods do not provide the required level of flexibility to operate in this dynamic environment. An autonomic product development process automation strategy is proposed in order to provide a flexible, standardized approach to product development process automation and to significantly reduce the software maintenance costs …


Optimal Placement Of Metal Foils In Ultrasonic Consolidation Process, Raji Rexavier May 2007

Optimal Placement Of Metal Foils In Ultrasonic Consolidation Process, Raji Rexavier

All Theses

Ultrasonic Consolidation is a combination of additive and subtractive
manufacturing processes resulting in considerable material waste. This waste is a
function of the geometry of the part being manufactured and of the relative
placement of the layer with respect to the metal bands. Thus the waste may be
minimized by careful choice of the layer angle and offset from the original
position.
Previous work done in this field had developed an automated algorithm which
optimally places and orients the individual slices of the STL file of the artifact
being manufactured. However, the problem was solved on a 2-D scale and …


Eigenvalue Optimization And Its Applications In Buckling And Vibration, Srinivas Gopal Krishna Jan 2007

Eigenvalue Optimization And Its Applications In Buckling And Vibration, Srinivas Gopal Krishna

LSU Doctoral Dissertations

Eigenvalue problems are of immense interest and play a pivotal role not only in many fields of engineering but also in pure and applied mathematics. An in-depth understanding of this class of problems is a pre-requisite for vibration and buckling analyses of structures. Design optimization of structures to prevent failure due to instability (bucking) and vibration introduces the problem of determining optimal physical parameters such that load carrying capacity or the fundamental natural frequency is maximized. A classical example of such problems is the Lagrange problem of determining the shape of the strongest column against buckling. The primary objective of …


Rolling Mill Optimization Using An Accurate And Rapid New Model For Mill Deflection And Strip Thickness Profile, Arif Sultan Malik Jan 2007

Rolling Mill Optimization Using An Accurate And Rapid New Model For Mill Deflection And Strip Thickness Profile, Arif Sultan Malik

Browse all Theses and Dissertations

This work presents improved technology for attaining high-quality rolled metal strip. The new technology is based on an innovative method to model both the static and dynamic characteristics of rolling mill deflection, and it applies equally to both cluster-type and non cluster-type rolling mill configurations. By effectively combining numerical Finite Element Analysis (FEA) with analytical solid mechanics, the devised approach delivers a rapid, accurate, flexible, high-fidelity model useful for optimizing many important rolling parameters. The associated static deflection model enables computation of the thickness profile and corresponding flatness of the rolled strip. Accurate methods of predicting the strip thickness profile …


Optimal Control Of Production And Distribution In A Supply Chain System Operating Under A Jit Delivery Policy, Pablo Biswas Jan 2007

Optimal Control Of Production And Distribution In A Supply Chain System Operating Under A Jit Delivery Policy, Pablo Biswas

LSU Doctoral Dissertations

This research deals with a supply chain system where the production or manufacturing facility operates under a just-in-time (JIT) environment, and the facility consists of raw material suppliers, manufacturers, and retailers where inventory of raw materials, work-in-process, and finished goods are involved, respectively. This work considers that the production of finished goods in one cycle starts just after the production or uptime in preceding cycle to minimize the idle time of the facility. Considering this scenario, inventory models are developed for different delivery situations: (a) perfect matching condition where no finished good remains after the shipments and (b) imperfect matching …