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Jet Velocity Dissipation And Modelling With Aeration, Stephen J. Schlenker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of natural aeration and fall height upon velocity dissipation and modelling were studied. Underwater velocities and void ratios (proportion of air volume to total volume) were measured along the jet centerline at various depths in the receiving pool under 1- and 2-inch diameter vertical circular free-falling jets. Maximum air bubble penetration depths were also measured. In the tests, the nozzle velocities were designed so that the two differently sized models would have equivalent Froude numbers for direct comparison of respective underwater parameters. Air entrainment-the natural development of air bubbles within a pool receiving a free-falling jet-causes voids to …

In Situ Determination Of Capillary Pressure And Relative Permeability Curves Using Well Logs., Adel Afifi Ibrahim

LSU Historical Dissertations and Theses

A pressure profile obtained from the formation tester defines the wettability, free water level, and hydrocarbon and water densities as well as the capillary pressure above the free water level. Correlating the pressure values to the water saturation values determined from the resistivity logs results in a capillary pressure/water saturation, $\rm P\sb{c}(S\sb{w}),$ curve characteristic of the reservoir. A relative permeability curve then can then be derived from this $\rm P\sb{c}(S\sb{w})$ curve using empirical relationships. This approach was tested in the laboratory using an eight-foot vertical sandstone core to simulate the formation. The core was fitted with electrode arrays, and resistivity …

Modification Of The Gleams Model To Incorporate Water Table And Subsurface Drainage., Manuel Reyes Reyes

LSU Historical Dissertations and Theses

The GLEAMS hydrology submodel was modified to account for the effects of shallow water table and subsurface drainage on runoff volume and soil loss. GLEAMS-WT (GLEAMS-Water Table) is a modified version of GLEAMS that accounts for shallow water table. GLEAMS-SWAT (GLEAMS with Subsurface drainage and WAter Table) is a modified version of GLEAMS that accounts for shallow water table and subsurface drainage. The simulation performances of GLEAMS, GLEAMS-WT, and GLEAMS-SWAT were evaluated by comparing their predictions with 7-years (1981-1987) of measured data from two plots of a runoff-erosion-drainage experiment at Baton Rouge, Louisiana. One plot was surface and subsurface drained, …

A Multiple Objective Formulation And Algorithm For The Layout Design Of Food Processing Facilities., Francisco A. Escobar

LSU Historical Dissertations and Theses

A multiple objective formulation, which incorporates robustness and constraint enforcement as design criteria, is utilized to model the layout of food processing facilities. These facilities are subject to the compliance with guidelines dictated by public health agencies, changes in product mix, and variation in production levels due to seasonality, which render existing layout design algorithms unsuitable for their design. The solution of the robust multiple objective formulation is implemented using a construction heuristic algorithm, MORCH, and an improvement heuristics, MOLAD. The MORCH/MOLAD hybrid algorithm performs comparably to well known heuristic algorithms where materials handling cost is used as the only …

A Blackboard Integration Of Manufacturing Databases Using An Intelligent Interface., David Anderson Koonce

LSU Historical Dissertations and Theses

The explosion of computer applications into the world of manufacturing along functional lines has produced the often mentioned "islands of automation." Although many issues and problems are involved in interfacing and integrating the databases that serve these applications, we can extract valuable data from these independent systems to provide important information to decision makers. This research resulted in the development of MIMIR (Multiple Integrated Manufacturing Information Resources), a decision support system based upon the blackboard architecture. The blackboard architecture extends the common expert system design to include multiple expert systems, termed Knowledge Sources (KS's), which combine to solve problems too …

Temporal And Spatial Characteristics Of Annual Maximum Precipitation In Louisiana., Babak Naghavi

LSU Historical Dissertations and Theses

A new procedure to compile and enhance hourly data has been proposed. A total of 92 rain gauges were used to generate 25 synthesized stations with long periods of record. Annual maximum series for various rainfall durations from the 25 synthesized stations were used for statistical analysis. Temporal and spatial characteristics of annual maximum precipitation are investigated and a new procedure for identification of climatologically homogeneous regions is proposed. This new procedure is based on statistical parameters of precipitation data and understanding of atmospheric processes. The mean annual precipitation, recorded extreme precipitations, geographical locations, and synoptic weather patterns were used …

Chemical Vapor Deposition To Titanium Dioxide Thin Films., Qingming Zhang

LSU Historical Dissertations and Theses

TiO$\sb2$ thin films have been prepared by the thermal decomposition of titanium tetra-isopropoxide (TTIP) in two low pressure chemical vapor deposition (LPCVD) reactors. The two reactors are the vertical tube hot-wall reactor and the stagnation point flow single-wafer cold-wall reactor. The effects of TTIP partial pressure, substrate temperature, gas flow rate, and reactor pressure on the growth rate of TiO$\sb2$ film were examined. Aerosol formation, wall effects, the effect of water content, and the effect of reactor geometry were also investigated. The experiments were performed in the substrate temperature range 225-400$\sp\circ$C, inlet TTIP partial pressure range $6.4\times10\sp{-4}$ $-$ 0.4 torr, …

Hydrologic Modelling With A Spatial Database., Richard Gilbert Greene

LSU Historical Dissertations and Theses

Hydrologic modelling can be enhanced and improved through the utilization of a Geographic Information System (GIS). Information can be stored and analyzed by the tools available within a GIS to create a spatial database that realistically represents a watershed for hydrologic modelling. This study presents an approach whereby the data available in the GIS determine the modelling strategy. The soil, topography and land cover data for the watershed were analyzed with the spatial analysis tools of a GIS to determine the hydrologic response areas. The coordinate values that define the locations and boundaries of features in the GIS were used …

Mobilization Of A Hydrophobic Organic Compound Using Surfactant For Soil Washing., Minwen Liu

LSU Historical Dissertations and Theses

Soil washing using surfactants is a promising alternative for the conventional pump-and-treat method of removing hydrophobic organic compounds. The interactions and the transport of the chemicals have been studied by batch and column experiments. Sodium dodecylsulfate (SDS), an anionic surfactant, and anthracene, a hydrophobic organic, were chosen as the representative surfactant and contaminant, respectively. Fine sand and native soil were used as formation media. The experimental results indicated that the maximum loss of SDS on native soil from the solution was observed when the aqueous SDS concentration was in the region of the critical micelle concentration, and this loss was …

Field Evaluation Of The Movement Of Agricultural Chemical Contaminants In Alluvial Soils With A Shallow Water Table., Orlino Agustin Mercado

LSU Historical Dissertations and Theses

The movement of agricultural chemical contaminants in alluvial soils with a shallow water table in a warm, humid environment was evaluated in this study. Bromide, a non-adsorbent tracer, was used to assess the pathways of water and solute in the soil profile. The movement and fate of three commonly used herbicides: Trifluralin, Metolachlor, and Metribuzin were determined. The data gathered from the herbicide study were used to compare with the results of simulation to validate the pesticide component of the GLEAMS model. The study was conducted at the Ben Hur Research Farm of the Louisiana Agricultural Experiment Station. Five relatively …

Dynamic Behavior Of Headspace Gases In Modified Atmosphere Packaging For Meat., Yanyun Zhao

LSU Historical Dissertations and Theses

Headspace gas composition in food packaging undergoes dynamic changes as a result of film permeability, postmortem metabolic activity, CO$\sb2$ absorption in water and lipid, and bacteria growth and respiration. A methodology to study dynamic behavior of headspace CO$\sb2$ was developed and used to identify the significant factors influencing CO$\sb2$ behavior within modified atmosphere packaging (MAP) systems for beef. Additionally, a mathematical structure suitable for modeling microbial growth in MAP systems was presented. A combined analytical and experimental method was developed to investigate headspace CO$\sb2$ changes during isothermal storage. The ideal gas law was used as a theoretical basis, and a …

A Computer Model Of The Role Of Text Integration In The Solution Of Arithmetic Word Problems, Mark David Leblanc

Doctoral Dissertations

Understanding arithmetic word problems involves a complex interaction of text comprehension and mathematical processes. This work presents a computer model of the hypothesized processes that are required of a young student solving arithmetic word problems, including the processes of sentence-level leading and text integration. Unlike previous computer simulations of word problem solving, which neglect the early stages of text processing, this model forces a detailed consideration of the linguistic process, which is being increasingly recognized as a primary source of difficulty. Three experiments were conducted to isolate critical test comprehension processes. Children's probability of solution was analyzed in regression analyses …

Hydrodynamic Studies Of The Flow Of Fine Particles Through A Fluidized Dense Bed Of Coarse Solids, Jaideep Talukdar

Doctoral Dissertations

This study explains the hydrodynamics of a circulating fluidized bed (CFB) system, the Battelle Multi-Solids Fluidized Bed System (MSFB). It consists of a circulating fluidized bed of fine particles superimposed on a bubbling bed of coarse solids.

One way to characterize such a system is to describe the mechanism of gas-solid flow through the bed. The gas flow in systems like these is through bubbles or slugs (regions of voids containing little or no solids). Bubbles are typically characterized by their size (length or diameter), their rise velocity, and their frequency.

Another task of the initial phase of this study …

Rapid Hydropyrolysis Of Coals For Production Of Liquid Hydrocarbons, Abdul Rahman Mohamed

Doctoral Dissertations

Production of fuels and chemicals from coal is becoming attractive due to potential high cost and uncertain supply of crude petroleum oil. Conventional techniques of coal liquefaction, though technically feasible, have been expensive due to hydrogen requirements, high pressure equipment, and high cost of commercial supported catalysts.

In this study, a novel technique for rapid hydropyrolysis of bituminous, subbituminous, and lignite coals has been investigated. Rapid hydropyrolysis is the process of heating at a fast rate to high temperature in a hydrogen environment. A coal sample in hydrogen atmosphere is targeted, in the absence of a catalyst, with a high …

Automatic Tool Path Generation For Numerically Controlled Machining Of Sculptured Surfaces, Xiaoxia Li

Doctoral Dissertations

This dissertation presents four new tool path generation approaches for numerically controlled machining of sculptured surfaces: TRI$\sb-$XYINDEX, FINISH, FIVEX$\sb-$INDEX, FIX$\sb-$AXIS$\sb-$INDEX. All of the above systems index the tool across the object surface in the Cartesian space so that evenly distributed tool paths are accomplished.

TRI$\sb-$XYINDEX is a three-axis tool path generation system which uses a surface triangle set (STS) representation of the surface for tool position calculations. Surface edges are detected with local searching algorithms. Quick tool positioning is achieved by selecting candidate elements of polygons. Test results show that TRI$\sb-$XYINDEX is more efficient when machining surfaces which are relatively …

Physical Behavior Of Computing Networks With An Emphasis On Routing, Peter George Drexel

Doctoral Dissertations

Combining powerful, local computing capability with inexpensive packet switched communication invites the creation of a new entity--the computing network. A computing network is a group of computer systems, interconnected by a packet switched network, which cooperate to accomplish a specific task.

Efficient communication between computer systems is critical. The accepted method of dealing with packet congestion is to limit network operation to linear regions ($\le$80 percent of total capacity).

Because of large parameter spaces, the behavior of computing networks is complex and not easily predictable with current techniques except in the simplest, linear region of operation. Since traditional approaches are …

Hydrodynamics And Heat Transfer Of Circulating Fluidized Bed, Chunming Qi

Doctoral Dissertations

The investigation of the hydrodynamics of gas-particle suspension in a circulating fluidized bed (CFB) focused on the radial (lateral) particle flux measurement, the mechanism of the radial particle concentration distribution, the mechanism and the model of particle convection heat transfer, and the pressure balance in the CFB loop, all of which affect the hydrodynamics, thermal efficiency and stability of a CFB.

The radial particle fluxes in a cold-flow CFB riser (14.0 cm i.d., 6.4 m high) were directly measured by specially designed probes. Two types of particles were used; glass beads of 200 $\mu$m diameter, and FCC catalyst of 70 …

Fiber-Reinforced Plastic Grids For The Structural Reinforcement Of Concrete Beams, Joseph Robert Yost

Doctoral Dissertations

The research presented in this dissertation evaluates the performance of simply supported concrete beams reinforced with a 2 dimensional Fiber Reinforced Plastic (FRP) grid. The non-corrosive, high strength properties characteristic of FRP materials make them a desirable structural reinforcement for concrete in environments where high concentrations of chloride ions are present.

The FRP grid under investigation is called NEFMAC and it is manufactured by Turay Industries of Tokyo Japan. NEFMAC is dimensionally fabricated as orthogonally intersecting longitudinal and transverse bars. The bars are continuous at the intersection points and, as such, there exists no preferred or strong direction within the …

A Massively Parallel Simd Processor For Neural Network And Machine Vision Applications, Michael A. Glover

Doctoral Dissertations

This thesis describes the MM32k, a massively parallel SIMD computer which is easy to program, high in performance, low in cost and effective for implementing highly parallel neural network architectures. The MM32k has 32768 bit serial processing elements, each of which has 512 bits of memory, and all of which are interconnected by a switching network. The entire system resides on a single PC-AT compatible card. It is programmed from the host computer using a C++ language class library which supports variable precision vector arithmetic. The MM32k also supports direct video input and output for machine vision applications.

Static And Dynamic Responses Of Prestressed Concrete Beams With Openings., Hany Ahmed Aly. Abdalla

Electronic Theses and Dissertations

Web openings in beams occur quite often in practice to provide convenient passage of environmental services. As a result, storey heights in buildings can be reduced resulting in major cost savings. Some openings generally give rise to excessive deflections and stresses which have to be taken into consideration. In this research, a theoretical and experimental study is carried out to determine the influence of openings on the static and dynamic responses of prestressed concrete beams. The effect of openings on the behaviour of such beams at different stages of loading--transfer stage, working stage, and ultimate stage--as well as under excitation …

Performance Evaluation Of An Auction-Based Manufacturing Cell Using Generalized Stochastic Petri Nets., Qiong. Zhou

Electronic Theses and Dissertations

An auction-based manufacturing system is characterized by the fact that the central control computer is eliminated and all the system entities make decisions locally through the negotiation process. The performance evaluation of such manufacturing systems is a new research topic because the traditional OR scheduling and dispatching models usually assume the existence of a central controller, which is, however, removed from an auction-based system. This thesis deals with the modelling and analysis of an auction-based flexible manufacturing cell, in which multiple machining centres are organized in two stages and are capable of processing multiple part types. The Generalized Stochastic Petri …

The Effect Of Beryllium And Titanium On Phase Transformation In Aluminum Bronze., Zhiwei (Kevin). Xu

Electronic Theses and Dissertations

The effects of Be and Ti microadditions on the transformation of tempered martensite aluminum bronze are investigated. The alloys investigated are the base alloy of nominal composition Cu-11Al, and the base alloy containing 0.20Be, 0.20Ti, and 0.20Be + 0.20Ti. Two hardness peaks are identified in the base alloy and base alloy containing 0.20Be, and one hardness peak in the base alloys containing 0.20Ti and 0.20Be + 0.20Ti, for aging between 400$\sp\circ$C and 500$\sp\circ$C following a solution treatment at 950$\sp\circ$C. A second minor increase in hardness results in the base alloy and base alloy containing 0.20Be, which is attributed to $\gamma\sb1$ …

Cryogenic Recovery Of Tire Rubber., Antonio (Tony). Mancina

Electronic Theses and Dissertations

A comprehensive investigation of the cryogenic recovery of tire rubber was conducted with laboratory, pilot plant and industrial equipment. Experiments were conducted with specimens of tire rubber to determine cooling curves for: (1) Scrap tire rubber dipped in liquid nitrogen. (2) Scrap tire rubber cooled by nitrogen vapour. (3) Virgin tire rubber dipped in liquid nitrogen. (4) Different size cubes of tire rubber cooled simultaneously by nitrogen vapour. (5) Tire rubber cooled and then recooled to investigate material degradation. Electron microphotographs of scrap and virgin tire treads were compared in terms of physical characteristics. The used tire rubber specimen appeared …

Tool Condition Monitoring In Turning Using Optical Sensors., Bin. Zhang

Electronic Theses and Dissertations

This thesis presents a study of tool condition monitoring in turning using optical sensors. The study focuses on the effect of tool wear on the surface finish and the dimensional inaccuracy of machined workpieces in turning operations. Experiments were conducted to measure the tool wear, the surface finish and the dimensional errors of the machined workpieces under different cutting conditions. Based on the experimental results, new mathematical models of surface finish prediction have been developed as functions of tool wear and cutting conditions, that is, cutting speed, feed rate, and depth of cut. In addition the relationship between tool tip …

A Non-Proportional Cyclic Plasticity Model For Metals With Ratchetting Effects., Srinivasan Madras Sivakumar

LSU Historical Dissertations and Theses

The path-dependent and nonlinear behavior of metallic materials subjected to cyclic loading is modelled using the proposed hardening rule. It uses mainly two surfaces, a yield and a limit surface and includes the memory effects through a separate surface called the memory surface which is obtained from a maximum stress criterion. The model considers the facts that the motion of the center of the yield surface in the stress space is mainly governed by the direction of the deviatoric stress rate and that the uniqueness of the solution requires nesting of the two surfaces. The model proposed satisfies both conditions …

A Monte Carlo Method In Contribution Response Transport., Charles Habib Aboughantous

LSU Historical Dissertations and Theses

A contribution response Monte Carlo method is developed and successfully applied to a sample deep penetration shielding problem. The random walk is simulated in most of its parts like in conventional M.C. by introducing the concept of a fictitious response particle. The scoring is peculiar to the proposed method and it need not be made at the detector itself so that computing time can be reduced by an order of magnitude or more depending on the geometry of the problem. The probability density functions are natural. They possess properties not encountered in conventional M.C. methods currently in use. The selection …

Calibration Chamber Studies Of Miniature Piezocone Penetration Tests In Cohesive Soil Specimens., Pradeep Unnikrishnan Kurup

LSU Historical Dissertations and Theses

The electronic piezocone penetrometer is potentially a very powerful in-situ testing device used for soil profiling and in the determination of engineering soil properties. The focus of this research is on the laboratory calibration of a miniature piezocone penetrometer in cohesive soil specimens instrumented to monitor the spatial pore pressure distribution. Two automated slurry consolidometers were developed for this research that were successful in preparing homogeneous and reproducible cohesive soil specimens. The results of eight miniature piezocone penetration tests (PCPT) and three miniature quasi-static friction cone penetration tests (QCPT) performed in a flexible double wall calibration chamber system are presented. …

High-Temperature High-Pressure Carbon Dioxide Removal From Coal Gas., Arpaden Silaban

LSU Historical Dissertations and Theses

The noncatalytic gas-solid reaction between CO$\sb2$(g) and CaO(s) to form CaCO$\sb3$(s) has been studied at high temperature and high pressure (HTHP) using a thermobalance reactor. This reaction could serve as the basis for a HTHP process for the separation of CO$\sb2$ from coal-derived gas. The kinetics of the calcination and carbonation reactions were studied as a function of temperature, pressure, CO$\sb2$ concentration, and background gas composition. Three sorbent precursors which produced CaO having a wide range of structural properties were selected for detailed kinetic studies. They were (i) reagent grade calcium carbonate, (ii) reagent grade calcium acetate, and (iii) commercial …

A Study Of Heat Transfer In Rotary Desorbers Used To Remediate Contaminated Soils., Charles Alan Cook

LSU Historical Dissertations and Theses

A comprehensive heat transfer model is developed which describes heat transfer phenomena in rotary desorbers. This model predicts the temperatures of the solids bed and gases in the desorber and the rate of water evaporation from the solids. Emphasis is placed on describing the heat transfer process between the rotating wall of a desorber and the adjacent bed of solids. A heat-balance integral method is used to model heat conduction from the wall to adjacent wet bed particles. This solution includes the effects of water evaporation near the wall and a thermal contact resistance between the wall and the first …

A Feature Recognition Algorithm For Polyhedral Parts., Yuan. Li

Electronic Theses and Dissertations

Currently, parts designed via CAD are defined and stored as geometric and topologic solids. The descriptions of these parts exist in terms of low-level information such as faces, edges and vertices or primitive volumes that are unrelated to manufacturing. Consequently, CAM is not able to make full use of the CAD-generated part description. To link between CAD and CAM, automatic interpretation of part description is very important. It involves a re-interpretation of the part description to extract manufacturing-specific semantic knowledge about the part. This knowledge can then enable the process planning and other CAM operations to proceed without human intervention. …