Engineering Commons^™

Enhanced Phosphate Flotation Using Novel Depressants, Lingyu Zhang

Theses and Dissertations--Mining Engineering

Froth flotation is the most efficient method for phosphate separation, which is a physic-chemical separation process based on the difference of surface properties between the valuable minerals and unwanted gangue minerals. However, the presence of clay slimes in the slurry after grinding consumes a large amount of reagents, decreases the collision probability between bubbles and minerals, prevents phosphate particle attachment to air bubbles, and thus considerably reduces flotation recovery and concentrate grade. Georgia Pacific Chemical, LLC has recently developed novel depressants, i.e., clay binders, which are a series of low molecular weight specialty polymers to help improve phosphate flotation performance …

Contingency Analysis Of Power Systems In Presence Of Geomagnetically Induced Currents, Sivarama Karthik Vijapurapu

Theses and Dissertations--Electrical and Computer Engineering

Geomagnetically induced currents (GIC) are manifestations of space weather phenomena on the electric power grid. Although not a new phenomenon, they assume great importance in wake of the present, ever expanding power grids. This thesis discusses the cause of GICs, methodology of modeling them into the power system and the ramifications of their presence in the bulk power system. GIC is treated at a micro level considering its effects on the power system assets like Transformers and also at a macro level with respect to issues like Voltage instability. In illustration, several simulations are made on a transformer & the …

Microstructural And Mineralogical Transformation Of Hydraulically Disposed Fly Ash—Implications To The Environment, Jabulani S. Mahlaba, Elsabe P. Kearsley, Richard A. Kruger

Coal Combustion and Gasification Products Journal Archive

Increasing amounts of coal are combusted annually to meet the ever-increasing energy demands. The inevitable by-products include fly ash and saline effluents, which require acceptable disposal. The aim of this article is to compare the effect of hydraulic disposal with dry ash dumping. The results indicate that the former carries more environmental benefits based on the physical, chemical, and mineralogical aspects that were investigated.

Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 2. Behavior Of Individual Particles, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li

Coal Combustion and Gasification Products Journal Archive

Handpicked carbon-rich particles (coal or char), mineral-rich particles (heated stones), and bonded stone aggregates (clinkers) from the upper and lower parts of a pilot-scale packed-bed combustor bed, designed to simulate conversion or combustion processes, were subjected to mineralogical and inorganic geochemical studies, in order to evaluate the reactions that may occur during carbon conversion at a particle-by-particle scale. The mineral matter of the carbon-rich particles was found to have higher proportions of carbonate minerals and kaolinite than the mineral-rich (stone) particles in the coal feedstocks used in the study, and to form phases such as anorthite, gehlenite, pyrrhotite, troilite, and …

Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 1. Bulk Coal And Ash Studies, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li

Coal Combustion and Gasification Products Journal Archive

Mineralogical and inorganic geochemical studies have been carried out on composite samples of six different coarse-crushed (,120 mm) feed coals tested in a pilot-scale packed-bed combustor designed to simulate conversion and some fixed-bed combustion processes, and also on composite samples of the ashes produced. The mineral matter of the coals consisted mainly of quartz, kaolinite, and Ca-bearing carbonate minerals (calcite, dolomite, aragonite), with minor proportions of illite, pyrite, and several other phases, along with some Ca in an organically associated form. The base to acid ratio of the coal ashes ranged from 0.1 to 0.3, due mainly to variations in …

Development Of Strategies To Minimize The Release Of Trace Elements From Coal Waste Sources, Mohammad Rezaee

Theses and Dissertations--Mining Engineering

To assess strategies aimed at minimizing the release of trace elements and the impact of disposal of coal waste materials on the environment, two long-term leaching experiments of up to five months duration were performed using waste materials from two plants cleaning high and low sulfur bituminous coal. The tests evaluated the mobility of major trace elements under different disposal scenarios: (i) a static leaching test designed to simulate the quiescent conditions encountered by coal waste material stored under water in a stable impoundment, and (ii) a dynamic test to simulate waste materials exposed to the atmosphere, either in variable …

Measuring Effectiveness Of Address Schemes For As-Level Graphs, Yinfang Zhuang

Theses and Dissertations--Computer Science

This dissertation presents measures of efficiency and locality for Internet addressing schemes.

Historically speaking, many issues, faced by the Internet, have been solved just in time, to make the Internet just work~\cite{justWork}. Consensus, however, has been reached that today's Internet routing and addressing system is facing serious scaling problems: multi-homing which causes finer granularity of routing policies and finer control to realize various traffic engineering requirements, an increased demand for provider-independent prefix allocations which injects unaggregatable prefixes into the Default Free Zone (DFZ) routing table, and ever-increasing Internet user population and mobile edge devices. As a result, the DFZ routing …

Co-Disposal Of Dry Fgd By-Product With Coal Gasification Ash And Inorganic Brines, Jabulani S. Mahlaba, P.C. Pretorius, Subal Maharajh, M.P. Augustyn

Coal Combustion and Gasification Products Journal Archive

There is a growing pressure from the environmental authorities and public bodies to reduce anthropogenic pollution. Stringent environmental legislation is being implemented for industries around the world, even more so for coal consuming industries. Control of gaseous emissions is one of the areas that are receiving considerable attention towards sustainable development. Coal combustion in coal-fired power utilities emits SO~x~ to the atmosphere. Dry flue gas desulphurisation (FGD) is a well known technology often used to mitigate sulphur emissions in coal-fired power utilities. It traditionally uses lime to neutralise SO~x~, and forms a mixture of anhydrite (CaSO~4~), and calcium sulphite (CaSO~3~). …

A Multi-Analytical Approach To Understand The Chemistry Of Fe-Minerals In Feed Coals And Ashes, Marcos L.S. Oliveira, Frans Waanders, Luis F.O. Silva, Andre Jasper, Carlos H. Sampaio, Dursman Mchabe, Rachel S. Hatch, James C. Hower

Coal Combustion and Gasification Products Journal Archive

Seven feed coals used in the Brazilian power generation industry were obtained and subsequently analysed together with fly ash and bottom ash from a major Brazilian power plant. The samples were investigated by means of room temperature FeMo¨ssbauer analyses, X-ray diffraction, Raman spectroscopy, scanning electron microscope and petrographic analysis. In addition, nanometer-sized crystalline phases in coals and ashes were characterised using an energy-dispersive X-ray spectrometer and a high-resolution transmission electron microscope. The major identified Fe-bearing minerals in the coals were found to be actinolite, ankerite, chalcopyrite, chlorite, goethite, illite, ilmenite, magnesioferrite, natrojarosite, pyrite, pyrrhotite, and siderite; whilst in the fly …

The Leachability Of Major Elements At Different Stages Of Weathering In Dry Disposed Coal Fly Ash, S.A. Akinyemi, A. Akinlua, W.M. Gitari, R.O. Akinyeye, L.F. Petrik

Coal Combustion and Gasification Products Journal Archive

Large quantities of solid residue are generated by coal-fired power stations in many parts of the World. The disposal and management of the unused fly ash remains a major problem to the environment. The weathered dry disposed ash cores comprise of major element constituents such as Al, Si, Ca, Mg, Fe, Mn, Na+ and K+. The mobility patterns and mineralogical associations of major elements in weathered dry disposed ash dumps aged 1-year-old, 8-year-old and 20-year-old from a coalfired power station in South Africa were investigated using a modified sequential extraction scheme. The extraction sequence was as follows: (1) water soluble, …

Development, Validation, And Application Of A Noninvasive Spinal Motion Measurement System, Shaun Kevin Stinton

University of Kentucky Doctoral Dissertations

Spontaneous vertebral fractures are a large and growing health care problem. Biomechanical factors, specifically, abnormal posture or gait‐related spinal motion may interact with age‐weakened bone to induce altered spinal biomechanics that in turn increase the likelihood of vertebral body fracture. This research takes steps towards the goal of reducing the number of vertebral fractures in two phases: 1) Validation of a noninvasive spinal motion measurement system in cadaver torsos and 2) Application of the measurement system in human subjects.

The cadaver study compared vertebral motion at 4 levels (T7,T12,L3,L5) as measured by adhesive skin markers versus motion measured by bone …

Mineralogy And Leaching Characteristics Of Coal Ash From A Major Brazilian Power Plant, Luis F.O. Silva, Colin R. Ward, James C. Hower, Maria Izquierdo, Frans Waanders, Marcos L.S. Oliveira, Zhongsheng Li, Rachel S. Hatch, Xavier Querol

Coal Combustion and Gasification Products Journal Archive

The feed coals, fly ashes and bottom ashes collected from seven different units in a major Brazilian PF power plant have been subjected to comprehensive mineralogical, geochemical, and petrographic studies, to investigate the links between feed coal and ash characteristics. Ashes from two of the units were collected while the coal was being co-fired with oil as part of the boiler start-up procedure, allowing the impact of oil co-firing on ash characteristics also to be evaluated. High proportions of unburnt carbon and high proportions of retained sulphur were found in the fly ashes produced during oil co-firing, probably reflecting less …

Evaluation Of Noise Impact Mitigation Protocols To Support Css, Ted Grossardt, Lou Cohn, Al Harris, Keiron Bailey, John Ripy

Kentucky Transportation Center Research Report

This research project developed and evaluated practical ways of involving the public in context sensitive sound mitigation strategies. The integrated use of photo montage, PowerPoint presentation, linked traffic sound files, and audience response systems demonstrated that significant visual and aural differences could be clearly portrayed and clear preferences could be expressed by citizens and professionals alike, even where the choice menu was quite complex.

Compaction Of Mixtures Of Hard Rocks And Soft Shales And Non-Durable Shales Using Impact Compactors, Tommy C. Hopkins

Kentucky Transportation Center Research Report

Impact roller compaction has been used to improve embankment and highway subgrades in South Africa, Australia, Europe, and China and other areas of the world. In September of 2003, the International Technology Scanning Program, sponsored by the Federal Highway Administration (FHWA), the American Association of State Highway and Transportation Officials (AASHTO), and the National Cooperative Highway Research Program of the Transportation Research Board, identified this technology as one of several foreign technologies and innovations that could significantly benefit U.S. transportation systems. The technology was high-lighted at the Fifth International Conference on the Bearing Capacity of Roads and Airfields in 1998 …

Effect Of Warning Devices On Curve Operating Speeds, Adam Vest, Nikiforos Stamatiadis, Adam Clayton, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this study is to evaluate the use of several warning signs and warning methods to identify those that have the greatest impact on reducing vehicle speeds when traversing a horizontal curve. Three sites were selected from a list of proposed sites for the testing of the various warning methods. Each warning treatment was installed and a five-day waiting period was allowed before operating speeds for the treatments were measured. The results of the various warning methods were mixed, however, some warning treatments were able to reduce operating speeds on a consistent basis. The most effective of these …

Analysis Of Inconsistencies Related To Design Speed, Operating Speed, And Speed Limits, Nikiforos Stamatiadis, Huafeng Gong

Kentucky Transportation Center Research Report

The objective of this research was to examine the relationship among design speeds, operating speeds and speed limits and address safety and operational concerns regarding the presence of disparities among these speed metrics. Roadway sections were selected throughout Kentucky based on the relationship between design speed and posted speed limit (greater or lower) and on the number of lanes (2 or 4). Speed data and roadway geometry data were collected along these sites to allow for the development of the appropriate models. The general conclusion for 2-lane highways is that the operating speed is different than the design speed indicating …

Resources--Money, Equipment, Manpower, Donald W. Lucas

Kentucky's Annual Forum on Transportation

No abstract provided.

Translating Vision Into Action Through Quality Management, Rodger B. Lewis

Kentucky's Annual Forum on Transportation

No abstract provided.

Recycled Materials In Kentucky Highway Construction, David Q. Hunsucker, Laura Whayne

Kentucky Transportation Center Research Report

The objectives of this study were to identify and list waste materials which should be recycled to reduce solid waste disposal; report current and past efforts of the Kentucky Department of Highways to utilize recycled and waste materials; determine through a thorough literature search and review, the efforts of other local, state, national and international transportation agencies to utilize recycled materials; and, present preliminary recommendations listing areas where additional recycling efforts appear promising, feasible and needed.

Waste materials that were identified which could be recycled to reduce solid waste disposal included demolition waste (building rubble, recycled concrete pavement, recycled asphalt …

Large-Stone Mixes For Reducing Rutting, Kamyar C. Mahboub

Kentucky Transportation Center Research Report

Large-stone mixes are becoming a very popular means for reducing rutting in flexible pavements. Aggregate interlock in large-stone mixes provides for very efficient dissipation of compressive and shear stresses that are known to be responsible for rutting and shoving in flexible pavements. This report documents mix design procedures and laboratory testing for characterization of rutting potential of large-stone asphalt mixes (LSAM) in Kentucky and particularly the Louisa Bypass project.

A series of large-stone aggregate gradations were studied. A promising aggregate gradation was selected in cooperation with Kentucky Department of Highway officials and representatives of the asphalt industry. Based upon the …

Remarks: Frank Shafroth, Frank Shafroth

Kentucky's Annual Forum on Transportation

The conference date of this session should be March 19, 1987 instead of March 21, 1987.

The Need For A Schema For The Classification Of Transitional (Shale) Materials, Robert C. Deen

Kentucky Transportation Center Research Report

The need for comprehensive information on the characteristics and behavior of earth materials has been recognized for many years, perhaps for as long as significant construction has taken place in and on the surface of the earth. In recent years, however, the magnitude and complexity of engineered construction has greatly increased, resulting in a corresponding increase in the need for information on the engineering properties of soil and rock materials for use in site selection, design, construction, and maintenance of major structures. Probably the most pressing need for such data is for use in preliminary considerations of site selection and …

A Soils Data System For Kentucky, Dwight Spradling

Kentucky Transportation Center Research Report

This report discusses the development of a computerized soils data system which facilitates collection, centralized storage, and retrieval of soils data developed by engineers and scientists for projects in Kentucky. Without such a system, much soils data are essentially lost after each project is completed. This system will provide data that can conveniently be used for developing preliminary sources of information for site investigation, for preparing regional soil maps, for land use planning, and for studying new and existing empirical relationships involving soil properties and characteristics.

Various types of data systems, the design of the system to include software and …

Engineering Data System For Bedrock Occurrences And Properties, D. J. Hagerty, Robert C. Deen, M. W. Palmer, C. D. Tockstein

Kentucky Transportation Center Research Report

The initial work plan included the development of a classification system based on index tests. An investigation of previous works in classification of rock on the basis of index tests showed that a variety of classification systems utilizing many different index tests had been developed. However, this survey showed that no generally applicable system had been developed and that little communication had been established between field investigators, facility designers, and those in charge of construction and maintenance of facilities. Therefore, the initial plan for work was modified to include the development of a comprehensive methodology for evaluation of rock. The …

Rock Evaluation For Engineered Facilities, D. J. Hagerty, Robert C. Deen, M. W. Palmer, C. D. Tockstein

Kentucky Transportation Center Research Report

The need for comprehensive information on the characteristics and behavior of earth materials has been recognized for many years, perhaps for as long as significant construction has taken place in and on the surface of the earth. In recent years, however, the magnitude and complexity of engineered construction has greatly increased, resulting in a corresponding increase in the need for information on the engineering properties of soil and rock materials, Direct testing of soil and rock can be utilized to furnish necessary information. However, both field and laboratory testing can be extremely expensive, particularly where testing must include applications of …

A Rock Classification Schema, Robert C. Deen, C. D. Tockstein, M. W. Palmer

Kentucky Transportation Center Research Report

The need for engineering data on earth materials for use in site selection, design, construction, and maintenance of major engineering structures is generally accepted. Probably the most pressing need is for such data to use in preliminary considerations of site selection and design alternatives. Maps and(or) surveys giving the areal distribution of earth materials and their characteristics, together with topographic maps available for many areas, would permit much preliminary work on engineering structures to be done without the engineer ever having to leave his office.

A Rock Evaluation Schema For Transporting Planning In Kentucky, C. D. Tockstein, M. W. Palmer

Kentucky Transportation Center Research Report

The initial goal was to devise an engineering classification system for intact rock samples based on simple index tests which could be used to categorize Kentucky surface and near-surface rock types and assist Kentucky Department of Transportation personnel in planning for transportation facilities. While conducting the literature survey, several facts become apparent:

1. a large number of rock classification systems, geologic and technical, general and specific, already existed;
2. an equally large number of index tests had been devised; and
3. there was a lack of communication among those involved in specialized areas of rock-related work (geologists, civil engineers, mining engineers, etc.), and, …

Noise Pollution And Abatement: A Review Of Literature, Kenneth R. Agent, Robert C. Deen

Kentucky Transportation Center Research Report

Complaints concerning traffic noise and possibly seismic vibrations emanating from highways would probably have been adjudicated on the basis of common law doctrines pertaining to "nuisances", "common enemy'', and ''power of relief" were it not for recent legislation and regulations directed toward protection of the total environment. In effect, "freedom from noise" has been added to the clean water, clean air, clean earth policies. Surely each of those policies are founded on public sentiment.

There have been a few instances where the Department has yielded relief because of traffic noise. Now safeguarding regulations seem inevitable.

In the past, this Division …

New Developments In Joint Sealing Practice For Longer Spans, Stewart C. Watson

Kentucky's Annual Forum on Transportation

No abstract provided.

The Application Of Nuclear Techniques To The Measurement Of Moisture And Density Of Highway Construction Materials, Robert C. Deen, J. D. Shackelford

Kentucky Transportation Center Research Report

In recent years much attention has been directed toward the application of neutron and gamma ray techniques to soil moisture and density measurements. This application of radiological measurements of these characteristics of materials of highway construction, of course, is of great interest to the highway industry since the performance of the total pavement system is highly dependent upon the condition of the embankment, subgrade, and base components of this system. An important measure of the state of condition of unconsolidated earth materials is their unit weights and moisture contents. The highway engineer undoubtedly would welcome any method or technique which …