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Articles 211 - 240 of 280
Full-Text Articles in Geological Engineering
Characterizing The Influence Of Carbon On The Flowrate And Disinfection Efficacy Of Household Ceramic Water Filters, Jessie Yvonne Hahn
Characterizing The Influence Of Carbon On The Flowrate And Disinfection Efficacy Of Household Ceramic Water Filters, Jessie Yvonne Hahn
Masters Theses
"Drinking water contamination is a major cause of disease in developing countries. Point of Use (POU) water treatment technologies generally have low initial cost and allow rapid availability of improved water. Ceramic pot filters (CPFs) are a POU water source treatment technology which filter water by gravity through a porous ceramic media. Some filters in use contain carbon remnants left from the fugitive pore former as a dark carbon core. Using disk-shaped experimental ceramic filters produced in the lab to have varying levels of carbon, the percent carbon present was measured and a visual analysis method was developed to determine …
Seasonal Variability And Long-Term Evolution Of Tropospheric Composition In The Tropics And Southern Hemisphere, K. M. Wai, S. Wu, A. Kumar, H. Liao
Seasonal Variability And Long-Term Evolution Of Tropospheric Composition In The Tropics And Southern Hemisphere, K. M. Wai, S. Wu, A. Kumar, H. Liao
Michigan Tech Publications, Part 1
Impacts on tropospheric composition in the tropics and the Southern Hemisphere from biomass burning and other emission sources are studied using a global chemical transport model, surface measurements and satellite retrievals. Seasonal variations in observed CO at remote island sites are examined. Easter Island (eastern Pacific Ocean) is impacted indirectly by the hemispheric zonal transport of CO due to the burning in southern Africa/South America, via the westerlies. An increasing trend in CO by 0.33 ppb yr-1 in the past decade at Ascension Island is attributed to the combined effects of South American/southern Africa burnings and the increases in CH4 …
Effects Of Stratospheric Ozone Recovery On Photochemistry And Ozone Air Quality In The Troposphere, H. Zhang, Shiliang Wu, Y. Huang, Y. Wang
Effects Of Stratospheric Ozone Recovery On Photochemistry And Ozone Air Quality In The Troposphere, H. Zhang, Shiliang Wu, Y. Huang, Y. Wang
Michigan Tech Publications, Part 1
There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor …
Synthesis And Characterization Of High-Iron Alite-Calcium Sulfoaluminate-Ferrite Cements Produced From Industrial By-Products, Tristana Y. Duvallet, Youngmin Zhou, Thomas L. Robl, Rodney Andrews
Synthesis And Characterization Of High-Iron Alite-Calcium Sulfoaluminate-Ferrite Cements Produced From Industrial By-Products, Tristana Y. Duvallet, Youngmin Zhou, Thomas L. Robl, Rodney Andrews
Coal Combustion and Gasification Products Journal Archive
Ordinary Portland cement (OPC) and calcium sulfoaluminate cement (CSAC) are well-known and commonly used construction materials. The clinker phases mainly responsible for their strength development are C3S (alite) in OPC, which hydrates to form a calcium silicate gel phase; and C4A3S ´ (calcium sulfoaluminate) in CSAC, which hydrates to rapidly form ettringite. The purpose of this work was to produce high-iron alite-calcium sulfoaluminate-ferrite cements, by combining C4AF (ferrite), from 5% to 50% by weight, to the C3S and C4A3S ´ clinker phases. Producing this alite-calcium sulfoaluminate-ferrite cement would decrease the requirement of bauxite in the raw materials, which would consequently …
Experimental And Modelling Evaluation Of Slagging Behaviour Of German Lignite, Martin Kaiser, Alexander Ilyushechkin
Experimental And Modelling Evaluation Of Slagging Behaviour Of German Lignite, Martin Kaiser, Alexander Ilyushechkin
Coal Combustion and Gasification Products Journal Archive
The behaviour of mineral matter is important for the characterisation of coal for use in entrained-flow gasification technologies. We investigated four behavioural characteristics—ash fusion temperatures (AFT), slag viscosity versus temperature profiles, temperatures of critical viscosity (TCV), and slag phase compositions—of Rhenish lignite coal ash using laboratory and modelling tools. Our modelling of AFT using coal ash composition provided a wide range of data, with only one (modified) model demonstrating agreement with experimental data. Experimental slag viscosity data were obtained over a temperature range from 1200uC to 1500uC. Where relevant, TCV was also measured. Comparison of these data to the calculated …
Fly Ash As A Potential Scrubber Of Acidic Wastes From The Phosphate Industries In Israel, Roy Nir Lieberman, Eli Lederman, Ithamar Pelly, Haim Cohen
Fly Ash As A Potential Scrubber Of Acidic Wastes From The Phosphate Industries In Israel, Roy Nir Lieberman, Eli Lederman, Ithamar Pelly, Haim Cohen
Coal Combustion and Gasification Products Journal Archive
Fly ash (FA) is produced in Israeli utilities via bituminous coal combustion. It is used as a cement additive or in concrete production, and its economic value is low. The FA produced in Israel is very basic (defined as class F) owing to ambient air quality standards that impose low sulfur content in the imported coals. Because the lime content is high (in the South African coal, ,10 wt%), it is a good potential chemical scrubber to acidic wastes. The phosphate industry in Israel produces mainly phosphate fertilizers and water-treatment products as well as phosphoric acid. The production methods rely …
Geochemistry And Mineralogy Of Coal-Fired Circulating Fluidized Bed Combustion Fly Ashes, Luis F.O. Silva, Marcos L.S. Oliveira, Rubens M. Kautzmann, Claudete G. Ramos, Maria Izquierdo, Shifeng Dai, Jennifer Wilcox, Jeremy Hoffman, James C. Hower
Geochemistry And Mineralogy Of Coal-Fired Circulating Fluidized Bed Combustion Fly Ashes, Luis F.O. Silva, Marcos L.S. Oliveira, Rubens M. Kautzmann, Claudete G. Ramos, Maria Izquierdo, Shifeng Dai, Jennifer Wilcox, Jeremy Hoffman, James C. Hower
Coal Combustion and Gasification Products Journal Archive
The fuel, bed ash, and fly ash were sampled from a circulating fluidized bed combustion (CFBC) unit at two times. The first sampling was a high-sulfur (S) coal-only run, and the second sampling coincided with an experimental burn of up to 10% switchgrass (Panicum virgatum) pressed pellets mixed with a high-S coal. The latter blend had a higher moisture content and a lower heating value than the coal-only fuel. Given the time between the samplings and the special needs for the experimental run, unavoidable changes in the coal and limestone complicate comparisons of the bed ash and fly ash chemistry …
Trends In Coal Utilization And Coal Combustion Product Production In Kentucky: Results Of The 2012 Survey Of Power Plants, James C. Hower, Gerald A. Thomas, Shelley G. Hopps
Trends In Coal Utilization And Coal Combustion Product Production In Kentucky: Results Of The 2012 Survey Of Power Plants, James C. Hower, Gerald A. Thomas, Shelley G. Hopps
Coal Combustion and Gasification Products Journal Archive
The University of Kentucky Center for Applied Energy Research has conducted a survey of Kentucky’s utility coal-fired power plants every 5 years since 1992. The survey includes a collection of the feed coal and the coal combustion products (CCPs). The latest collection was in 2012, with the accompanying information survey covering trends in 2011. Overall coal-fired energy production decreased, and the nature of the CCPs changed for a number of reasons, including but not limited to, increased gas production in the Appalachians, a series of warm winters, energy conservation, depletion of Appalachian coal reserves, and utility responses to regulations. From …
The John Zink Hamworthy Combustion Handbook, 2nd Edition, Volume 1: Fundamentals, Edited By Charles E. Baukal, Jr., Crc Press, Boca Raton, Fl, 2013., Payal A. Chandan
The John Zink Hamworthy Combustion Handbook, 2nd Edition, Volume 1: Fundamentals, Edited By Charles E. Baukal, Jr., Crc Press, Boca Raton, Fl, 2013., Payal A. Chandan
Coal Combustion and Gasification Products Journal Archive
No abstract provided.
Location Of Cerium In Coal-Combustion Fly Ashes: Implications For Recovery Of Lanthanides, James C. Hower, John G. Groppo, Prakash Joshi, Shifeng Dai, David P. Moecher, Michelle N. Johnston
Location Of Cerium In Coal-Combustion Fly Ashes: Implications For Recovery Of Lanthanides, James C. Hower, John G. Groppo, Prakash Joshi, Shifeng Dai, David P. Moecher, Michelle N. Johnston
Coal Combustion and Gasification Products Journal Archive
Given the worldwide demand for rare earth elements (REEs) in modern electronics, all potential sources of the REEs should be investigated. Coal-combustion fly ash represents a potential source of REEs. Fly ashes, derived from the combustion of coals from Kentucky in the United States and Jungar in China, were examined by wavelength-dispersive spectrometry electron microprobe analysis of epoxy-bound polished pellets. From previous studies, it was known that the REEs did not show any enrichment relative to flue gas temperature at the point of collection or to the particle size, that is, external surface area, of the particles. Cerium, the most …
Chemical Partitioning And Mobility Of Trace Elements In Dry Disposed Weathered Ash Conditioned With High-Saline Effluents, S.A. Akinyemi, A. Akinlua, W.M. Gitari, R.O. Akinyeye, L.F. Petrik
Chemical Partitioning And Mobility Of Trace Elements In Dry Disposed Weathered Ash Conditioned With High-Saline Effluents, S.A. Akinyemi, A. Akinlua, W.M. Gitari, R.O. Akinyeye, L.F. Petrik
Coal Combustion and Gasification Products Journal Archive
Weinvestigated the mobility of inorganic elements in the ash dump due to chemical interaction of weathered dry disposed ash conditioned with high-saline effluents and ingressed CO2 from atmosphere and percolating rainwater. Drilled ash core samples collected from dry disposed ash dump at a South African coal-burning power station were characterized using X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses. A modified sequential extraction procedure was selected to determine the mineralogical association of the investigated elements in the 1-year-old drilled ash cores. Major mineral phases are quartz and mullite and other minor phases included hematite, lime, calcite, anorthite, mica, and enstatite. …
Effects Of Coal Combustion By-Product–Encapsulated Ammonium Nitrate On Wheat Yield And Uptake Of Nitrogen And Metals, Eton E. Codling
Effects Of Coal Combustion By-Product–Encapsulated Ammonium Nitrate On Wheat Yield And Uptake Of Nitrogen And Metals, Eton E. Codling
Coal Combustion and Gasification Products Journal Archive
Ammonium nitrate (AN) is an essential plant nutrient for plant growth. Ammonium nitrate is also an ingredient in explosives. Research is being conducted on reducing the explosiveness of AN by encapsulating it with the use of coal by-products. The objective of this greenhouse pot study was to determine the effects of class C and F fly ash and flue gas desulfurization-gypsum-encapsulated AN on biomass, grain, and straw yield and nitrogen and metals uptake by wheat. Encapsulated AN was mixed with a low-nitrogen soil at 56 and 112 kg N ha^-1^, as well as unencapsulated AN as a control, and planted …
Geotechnical Characterization Of Clinker-Stabilized Fly Ash–Coal Mine Overburden Mixes For Subbase Of Mine Haul Road, Soumya Ranjan Mallick, Manoj Kumar Mishra
Geotechnical Characterization Of Clinker-Stabilized Fly Ash–Coal Mine Overburden Mixes For Subbase Of Mine Haul Road, Soumya Ranjan Mallick, Manoj Kumar Mishra
Coal Combustion and Gasification Products Journal Archive
Fly ash is a major by-product of thermal power plants that adversely affects land, water, and air. Its gainful utilization in many areas is being continuously explored. Use of fly ash in opencast coal mine haul road construction is one such option. This article reports detailed laboratory investigations carried out on clinker-stabilized fly ash–mine overburden mixes to evaluate their suitability for subbase of mine haul roads. Composite materials were prepared from fly ash, mine overburden, and clinker at different proportions. Proctor compaction test, unconfined compressive strength (UCS), and ultrasonic pulse velocity tests were carried out at different curing periods. UCS …
A Note On The Occurrence Of Yttrium And Rare Earth Elements In Coal Combustion Products, James C. Hower, Shifeng Dai, Vladimir V. Seredin, Lei Zhao, Irena J. Kostova, Luis F.O. Silva, Sarah M. Mardon, Gulbin Gurdal
A Note On The Occurrence Of Yttrium And Rare Earth Elements In Coal Combustion Products, James C. Hower, Shifeng Dai, Vladimir V. Seredin, Lei Zhao, Irena J. Kostova, Luis F.O. Silva, Sarah M. Mardon, Gulbin Gurdal
Coal Combustion and Gasification Products Journal Archive
There is an international need for a variety of lanthanide elements (rare earth elements, or REEs) in modern electronic and related components. This has led to a desire to broaden production from both previously productive locations and to expand production to new sources, possibly including coal-derived fly ash. The concentration of lanthanides in coal-combustion fly ash depends on a number of factors, one of the most important being the concentration of the elements in the feed coal. Unlike some elements, such as Zn and As, the REE concentration is largely not a function of element volatility. In this study, we …
Fouling Intensity Of Three Indian Coals, S. Balakrishnan, R. Nagarajan
Fouling Intensity Of Three Indian Coals, S. Balakrishnan, R. Nagarajan
Coal Combustion and Gasification Products Journal Archive
Ash particles can arrive at heat-transfer surfaces either in solid (solidified) state or in molten state, depending on the factors such as location inside the boiler, temperature, and residence time. In this study, arrival of ash particles in solid state, which can occur in the convective section of the boiler, was considered. Apart from the inertial force that drives particles .10 mmto the surface, the low-melting inorganic alkali vapors play a vital role in deposit formation by promoting sticking. Chemical equilibrium calculations were performed to calculate the equilibrium composition of flue gas, as well as the amount of condensable inorganic …
Chemical Weathering And Mobility Of Inorganic Species In Dry Disposed Ash: An Insight From Geochemical Fractionation And Physicochemical Analysis, S.A. Akinyemi, W.M. Gitari, A. Akinlua, L.F. Petrik
Chemical Weathering And Mobility Of Inorganic Species In Dry Disposed Ash: An Insight From Geochemical Fractionation And Physicochemical Analysis, S.A. Akinyemi, W.M. Gitari, A. Akinlua, L.F. Petrik
Coal Combustion and Gasification Products Journal Archive
The burning of low-grade coal produces vast amounts of ash and other solid by-products. In South Africa, coal combustion by-products undergo disposal on land as dry heaps or slurried to dams. In this study, the geochemical partitioning, transport, and mobility of elements in dry disposed ash dumps were investigated using a modified sequential extraction scheme. The chemical and mineralogical compositions of 50 drilled core samples were investigated by X-ray fluorescence (XRF), X-ray diffraction (XRD), and inductively coupled plasma mass spectrometry. Ternary plots of major elements as determined by XRF showed that the 15-year-old and 2-week-old dry disposed ashes are sialic, …
Impacts Of Changes In Land Use And Land Cover On Atmospheric Chemistry And Air Quality Over The 21st Century, S. Wu, L. J. Mickley, J. O. Kaplan, D. J. Jacob
Impacts Of Changes In Land Use And Land Cover On Atmospheric Chemistry And Air Quality Over The 21st Century, S. Wu, L. J. Mickley, J. O. Kaplan, D. J. Jacob
Michigan Tech Publications, Part 1
The effects of future land use and land cover change on the chemical composition of the atmosphere and air quality are largely unknown. To investigate the potential effects associated with future changes in vegetation driven by atmospheric CO 2 concentrations, climate, and anthropogenic land use over the 21st century, we performed a series of model experiments combining a general circulation model with a dynamic global vegetation model and an atmospheric chemical-transport model. Our results indicate that climate-and CO 2-induced changes in vegetation composition and density between 2100 and 2000 could lead to decreases in summer afternoon surface ozone of up …
Microstructural And Mineralogical Transformation Of Hydraulically Disposed Fly Ash—Implications To The Environment, Jabulani S. Mahlaba, Elsabe P. Kearsley, Richard A. Kruger
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.
Cordyline Fruticosa Growth And Soil Microbial Quality With Topical Application Of Coal Combustion By-Products Aggregates, Sangchul Hwang, Isomar Latorre, Eileen Irizarry
Cordyline Fruticosa Growth And Soil Microbial Quality With Topical Application Of Coal Combustion By-Products Aggregates, Sangchul Hwang, Isomar Latorre, Eileen Irizarry
Coal Combustion and Gasification Products Journal Archive
Coal combustion by-products aggregates (CCAs) are a solidified composite of fly and bottom ashes (2:1, by wt). Here, we assessed the feasibility of beneficial use of CCAs as a soil amendment or conditioner by conducting an outdoor experiment with Cordyline fruticosa (lucky plant) to determine its growth and soil microbial quality under the influence of topical CCA application (95 tons ha21). Enhanced growth of C. fruticosa with CCA application was noted, with respect to plant height, growth rate, leaf size, and leaf chlorophyll intensity. Soil dehydrogenase activity and total heterotrophic bacteria count were greater with topical CCA application, especially in …
Influence Of Activator Solution Formulation On Fresh And Hardened Properties Of Low-Calcium Fly Ash Geopolymer Concrete, Carlos Montes, Erez N. Allouche
Influence Of Activator Solution Formulation On Fresh And Hardened Properties Of Low-Calcium Fly Ash Geopolymer Concrete, Carlos Montes, Erez N. Allouche
Coal Combustion and Gasification Products Journal Archive
The effect of the composition of activator solutions on fresh and hardened properties of geopolymer concrete was investigated. Research variables included liquid sodium silicate product (DH, NH, and StarH), sodium hydroxide molar concentration (6, 10, and 14), and sodium silicate–to–sodium hydroxide ratio (1, 2, and 3). Response variables were compressive strength, corrosion resistance expressed as remaining compressive strength and mass loss, and flowability. Results were analyzed using Minitab statistical software. Findings suggest that activator solution formulation has a significant effect on the properties of the resulting geopolymer binder. The experimental design used was found effective in establishing the optimum activator …
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
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
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 …
Potential Indoor Air Exposures And Health Risks From Mercury Off-Gassing Of Coal Combustion Products Used In Building Materials, Christopher M. Long, Sonja N. Sax, Ari S. Lewis
Potential Indoor Air Exposures And Health Risks From Mercury Off-Gassing Of Coal Combustion Products Used In Building Materials, Christopher M. Long, Sonja N. Sax, Ari S. Lewis
Coal Combustion and Gasification Products Journal Archive
Coal combustion products (CCPs), including coal fly ash (CFA) and flue gas desulfurization (FGD) gypsum, have gained accepted use as substitutes for traditional substances in building materials. Because of the presence of mercury (Hg) in CCP materials, some concerns have been raised regarding the potential for Hg to off-gas from building materials into indoor air. Risk assessment offers a well-accepted, objective framework in which to determine whether such off-gassing could result in humanexposures of health concern. We thus conducted a screening-level human health risk assessment to estimate worst-case inhalation risks from indoor air exposures to Hg for multiple CCP utilization …
Quantifying The Benefits Of Using Flue Gas Desulfurization Gypsum In Sustainable Wallboard Production, Jin Cheol Lee, Sabrina L. Bradshaw, Tuncer B. Edil, Craig H. Benson
Quantifying The Benefits Of Using Flue Gas Desulfurization Gypsum In Sustainable Wallboard Production, Jin Cheol Lee, Sabrina L. Bradshaw, Tuncer B. Edil, Craig H. Benson
Coal Combustion and Gasification Products Journal Archive
Electric utilities produce more than 11.2 Mt of flue gas desulfurization (FGD) gypsum annually. Approximately 7.5 Mt is used in wallboard production. This article examines the environmental and cost benefits associated with replacement of natural gypsum in wallboard with FGD gypsum. A life-cycle analysis program was used to quantify the benefits of using FGD gypsum from electric power production in wallboard construction. Comparisons were made between energy consumption, water use, and greenhouse gas (GHG) emissions associated with obtaining and processing virgin gypsum material and those with FGD gypsum. The added impact of disposing of the unused FGD gypsum in landfills …
Waste Classification Of Slag Generated In A Pilot-Scale Entrained-Flow Gasifier, Ashleigh Cousins, Robin W. Hughes, David J. Mccalden, Dennis Y. Lu, Edward J. Anthony
Waste Classification Of Slag Generated In A Pilot-Scale Entrained-Flow Gasifier, Ashleigh Cousins, Robin W. Hughes, David J. Mccalden, Dennis Y. Lu, Edward J. Anthony
Coal Combustion and Gasification Products Journal Archive
Series of gasification tests have been completed in the pilot-scale entrained-flow slagging gasifier at CanmetENERGY using Canadian coals, oil-sand coke, and blends of these fuels to determine if the produced slags are nonhazardous in nature. Solid wastes generated during these tests were analyzed for their trace metals, crystallinity, and toxic constituent leaching tendency in an attempt to provide more insight into the possibility of disposal or by-product use of gasifier-produced solid waste. The gasification tests were performed at conditions representative of commercial gasifiers using a dry-fuel-feed configuration. The lower-volatility elements were found to partition between the slag and process-water solids …
A Deterministic Method Of Predicting Long-Term Pile Capacity In Cohesive Soils After The Dissipation Of Excess Pore Water Pressure, Eric J. Steward
A Deterministic Method Of Predicting Long-Term Pile Capacity In Cohesive Soils After The Dissipation Of Excess Pore Water Pressure, Eric J. Steward
Doctoral Dissertations
Pile setup or freeze is a phenomenon where the bearing capacity of a pile increases over time both during and after the dissipation of pore pressure and the stabilization of lateral earth pressure. Driven piles gain capacity after installation because of the dissipation of excess pore pressure and soil aging. Incorporating accurate setup prediction into the design of the piles can significantly reduce the cost of many projects by reducing the size or number of required piles. Various simple, empirical mathematical models have been developed to predict pile setup. However, these models are often unreliable, resulting in very conservative designs. …
Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, J. S. Fu, S. Wu, L. J. Mickley
Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, J. S. Fu, S. Wu, L. J. Mickley
Michigan Tech Publications, Part 1
Simulations of present and future average regional ozone and PM 2.5 concentrations over the United States were performed to investigate the potential impacts of global climate change and emissions on regional air quality using CMAQ. Various emissions and climate conditions with different biogenic emissions and domain resolutions were implemented to study the sensitivity of future air quality trends from the impacts of changing biogenic emissions. A comparison of GEOS-Chem and CMAQ was performed to investigate the effect of downscaling on the prediction of future air quality trends. For ozone, the impacts of global climate change are relatively smaller when compared …
Physical Impact Of Waterjet-Based Sediment Remediation On Benthic Organisms, Grace Harper, Andrew Curtis Elmore, Christopher Redell, Gavin Risley, Joel Gerard Burken
Physical Impact Of Waterjet-Based Sediment Remediation On Benthic Organisms, Grace Harper, Andrew Curtis Elmore, Christopher Redell, Gavin Risley, Joel Gerard Burken
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Adding Activated Carbon to Sediments Has Been Shown to Be an Effective Means of Reducing the Bioavailability of Certain Contaminants. the Current State of the Practice is to Mechanically Mix Activated Carbon to a Target Concentration of 3 Percent at Depths of Approximately 30 Cm using a Rotovator or Similar Construction Equipment. Waterjets Have Been Used to Cut Hard Material using a Mixture of Water and an Abrasive. If Activated Carbon is Substituted for the Abrasive, Waterjets Have the Potential to Use Surface Injection as a Replacement for Mechanical Mixing during Sediment Remediation. a Perceived Benefit of Waterjet-Based Sediment Remediation …
Effect Of Additive On The Performance Characteristics Of Centrifugal And Progressive Cavity Slurry Pumps With High Concentration Fly Ash Slurries, Sunil Chandel, S.N. Singh, V. Seshadri
Effect Of Additive On The Performance Characteristics Of Centrifugal And Progressive Cavity Slurry Pumps With High Concentration Fly Ash Slurries, Sunil Chandel, S.N. Singh, V. Seshadri
Coal Combustion and Gasification Products Journal Archive
Slurry pumps that are used in the hydraulic transportation of fly ash slurries through pipes in thermal power plants can be broadly classified into two main categories namely positive displacement and centrifugal pumps. The two types of pumps differ considerably in construction as well as in operating principle compared to the conventional pumps. The present study reports the effect of additive on the performance characteristics of centrifugal and progressive cavity screw pumps with fly ash slurries at high concentrations (above Cw < 50% by weight). Mixture of sodium carbonate and Henko detergent (5:1) at a concentration of 0.2% by weight has been used as an additive. For each type of pump, the effect of additive on the performance characteristics has been experimentally evaluated at rated speed with fly ash slurries in the concentration range of 50 to 70% by weight. The pump total head, overall efficiency and pump input power as a function of flow rate have been measured. The results obtained from the centrifugal slurry pump performance show that at rated speed, the performance of the pump improves with the addition of drag reducing additive. In the case of progressive cavity screw pump, pump performance characteristics and behavior were completely different as compared to the centrifugal slurry pump. At rated speed, the performance of screw pump deteriorates with the addition of drag reducing soap solution.
Zinc Speciation In Power Plant Burning Mixtures Of Coal And Tires, Luis F.O. Silva, Marcos L.S. Oliveira, Carmen Serra, James C. Hower
Zinc Speciation In Power Plant Burning Mixtures Of Coal And Tires, Luis F.O. Silva, Marcos L.S. Oliveira, Carmen Serra, James C. Hower
Coal Combustion and Gasification Products Journal Archive
Fly ash from the cyclone-boiler co-combustion of high-S, high volatile bituminous coal and tire-derived fuel (tdf) was studied using a variety of chemical, optical, and microbeam techniques. Fly ash, dominated by Al-Si glass with lesser amounts of coalderived carbons, Fe-spinels, and tire-derived carbons, has Zn concentrations ranging from 2200 ppm (1st ESP row) to 6900 ppm Zn (3rd ESP row). Zinc occurs in Zn-rich nanoparticles in the Al-Si glass phases and as ZnO in amorphous and crystalline nanominerals, Fe- and Zn-sulfides, Pb-Al-Fe sulfates, and Zn sulfates. Iron-rich, Al- and Ti-bearing spinels contain accessory Zn2+,Cr3+,Mn2+, and Pb2+. Fe-sulfates and phosphates nanoparticles …