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Articles 1 - 19 of 19
Full-Text Articles in Engineering
Synergistic Interactions Of H2 And N2 With Molten Gallium In The Presence Of Plasma, Maria L. Carreon, Daniel F. Jaramillo-Cabanzo, Indira Chaudhuri, Madhu Menon, Mahendra K. Sunkara
Synergistic Interactions Of H2 And N2 With Molten Gallium In The Presence Of Plasma, Maria L. Carreon, Daniel F. Jaramillo-Cabanzo, Indira Chaudhuri, Madhu Menon, Mahendra K. Sunkara
Physics and Astronomy Faculty Publications
The present study examines the interaction of hydrogen and nitrogen plasmas with gallium in an effort to gain insights into the mechanisms behind the synergetic effect of plasma and a catalytic metal. Absorption/desorption experiments were performed, accompanied by theoretical-computational calculations. Experiments were carried out in a plasma-enhanced, Ga-packed, batch reactor and entailed monitoring the change in pressure at different temperatures. The results indicated a rapid adsorption/dissolution of the gas into the molten metal when gallium was exposed to plasma, even at a low temperature of 100 °C. The experimental observations, when hydrogen was used, indicate that gallium acts as a …
Three-Dimensional Vapor Intrusion Modeling Approach That Combines Wind And Stack Effects On Indoor, Atmospheric, And Subsurface Domains, Elham Shirazi, Kelly G. Pennell
Three-Dimensional Vapor Intrusion Modeling Approach That Combines Wind And Stack Effects On Indoor, Atmospheric, And Subsurface Domains, Elham Shirazi, Kelly G. Pennell
Civil Engineering Faculty Publications
Vapor intrusion (IV) exposure risks are difficult to characterize due to the role of atmospheric, building and subsurface processes. This study presents a three-dimensional VI model that extends the common subsurface fate and transport equations to incorporate wind and stack effects on indoor air pressure, building air exchange rate (AER) and indoor contaminant concentration to improve VI exposure risk estimates. The model incorporates three modeling programs: (1) COMSOL Multiphysics to model subsurface fate and transport processes, (2) CFD0 to model atmospheric air flow around the building, and (3) CONTAM to model indoor air quality. The combined VI model predicts AER …
Unmanned Aerial Systems For Monitoring Trace Tropospheric Gases, Travis J. Schuyler, Marcelo I. Guzman
Unmanned Aerial Systems For Monitoring Trace Tropospheric Gases, Travis J. Schuyler, Marcelo I. Guzman
Chemistry Faculty Publications
The emission of greenhouse gases (GHGs) has changed the composition of the atmosphere during the Anthropocene. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating the contributions of different processes to radiative forcing. Currently there is no mobile platform that is able to quantify trace gases at altitudes(UASs) can be deployed on-site in minutes and can support the payloads necessary to quantify trace gases. Therefore, current efforts combine the use of UASs available on the civilian market with inexpensively designed analytical systems for monitoring atmospheric trace gases. In this context, this perspective introduces the …
Catalytic Oxidation And Depolymerization Of Lignin In Aqueous Ionic Liquid, Lalitendu Das, Siquan Xu, Jian Shi
Catalytic Oxidation And Depolymerization Of Lignin In Aqueous Ionic Liquid, Lalitendu Das, Siquan Xu, Jian Shi
Biosystems and Agricultural Engineering Faculty Publications
Lignin is an integral part of the plant cell wall, which provides rigidity to plants, also contributes to the recalcitrance of the lignocellulosic biomass to biochemical and biological deconstruction. Lignin is a promising renewable feedstock for aromatic chemicals; however, an efficient and economic lignin depolymerization method needs to be developed to enable the conversion. In this study, we investigated the depolymerization of alkaline lignin in aqueous 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] under oxidizing conditions. Seven different transition metal catalysts were screened in presence of H2O2 as oxidizing agent in a batch reactor. CoCl2 and …
Reducing Equifinality Using Isotopes In A Process-Based Stream Nitrogen Model Highlights The Flux Of Algal Nitrogen From Agricultural Streams, William I. Ford, James F. Fox, Erik Pollock
Reducing Equifinality Using Isotopes In A Process-Based Stream Nitrogen Model Highlights The Flux Of Algal Nitrogen From Agricultural Streams, William I. Ford, James F. Fox, Erik Pollock
Biosystems and Agricultural Engineering Faculty Publications
The fate of bioavailable nitrogen species transported through agricultural landscapes remains highly uncertain given complexities of measuring fluxes impacting the fluvial N cycle. We present and test a new numerical model named Technology for Removable Annual Nitrogen in Streams For Ecosystem Restoration (TRANSFER), which aims to reduce model uncertainty due to erroneous parameterization, i.e., equifinality, in stream nitrogen cycle assessment and quantify the significance of transient and permanent removal pathways. TRANSFER couples nitrogen elemental and stable isotope mass‐balance equations with existing hydrologic, hydraulic, sediment transport, algal biomass, and sediment organic …
Enhancements In Mass Transfer For Carbon Capture Solvents Part I: Homogeneous Catalyst, Leland R. Widger, Moushumi Sarma, Jonathan J. Bryant, David S. Mannel, Jesse G. Thompson, Cameron A. Lippert, Kunlei Liu
Enhancements In Mass Transfer For Carbon Capture Solvents Part I: Homogeneous Catalyst, Leland R. Widger, Moushumi Sarma, Jonathan J. Bryant, David S. Mannel, Jesse G. Thompson, Cameron A. Lippert, Kunlei Liu
Center for Applied Energy Research Faculty and Staff Publications
The novel small molecule carbonic anhydrase (CA) mimic [CoIII(Salphen-COO−)Cl]HNEt3 (1), was synthesized as an additive for increasing CO2 absorption rates in amine-based post-combustion carbon capture processes (CCS), and its efficacy was verified. 1 was designed for use in a kinetically slow but thermally stable blended solvent, containing the primary amines 1-amino-2-propanol (A2P) and 2-amino-2-methyl-1-propanol (AMP). Together, the A2P/AMP solvent and 1 reduce the overall energy penalty associated with CO2 capture from coal-derived flue gas, relative to the baseline solvent MEA. 1 is also effective at increasing absorption kinetics of kinetically fast solvents, such …
Solvent Degradation And Emissions From A 0.7mwe Pilot Co2 Capture System With Two-Stage Stripping, Jesse Thompson, Heather Nikolic, Megan Combs, Saloni Bhatnagar, Jonathan Pelgen, Keemia Abad, Kunlei Liu
Solvent Degradation And Emissions From A 0.7mwe Pilot Co2 Capture System With Two-Stage Stripping, Jesse Thompson, Heather Nikolic, Megan Combs, Saloni Bhatnagar, Jonathan Pelgen, Keemia Abad, Kunlei Liu
Center for Applied Energy Research Faculty and Staff Publications
The UKy-CAER team successfully tested an advanced 0.7 MWe post-combustion CO2 capture system on a coal-fired power plant using a heat integration process combined with two-stage stripping to enhance the CO2 absorber performance. One of the unique feature of the UKy-CAER integrated process is a two-stage stripping unit for solvent regeneration. The secondary stripper is empowered by the heat rejection from a conventional steam-heated (primary) stripper. The secondary stripper outlet stream at the commercial scale can be used as boiler secondary combustion air, consequently enriching the flue gas with CO2, resulting in less energy penalty required …
Development Of A Methodology To Determine Antibiotic Concentrations In Water Samples Using High-Pressure Liquid Chromatography, Tahnee Qualls, Carmen T. Agouridis, Manish Kulshrestha
Development Of A Methodology To Determine Antibiotic Concentrations In Water Samples Using High-Pressure Liquid Chromatography, Tahnee Qualls, Carmen T. Agouridis, Manish Kulshrestha
Biosystems and Agricultural Engineering Faculty Publications
Antibiotic concentrations are typically measured using solid-phase extraction along with liquid chromatography, but this process is not practical due to a large number of man hours involved. The use of a lyophilizer with high-pressure liquid chromatography (HPLC) is an accurate and cost-effective method of analyzing antibiotics in water samples. An initial antibiotic analysis methodology was developed with the goal of concentrating antibiotics in water samples for greater detection; however, it was observed that the methodology required additional refinement to improve accuracy, particularly when manure was present in the water samples. Based on prior tetracycline antibiotic research, we hypothesized that sample …
Mapping And Integrating Value Creation Factors With Life-Cycle Stages For Sustainable Manufacturing, P. Bilge, S. Emec, G. Seliger, Ibrahim S. Jawahir
Mapping And Integrating Value Creation Factors With Life-Cycle Stages For Sustainable Manufacturing, P. Bilge, S. Emec, G. Seliger, Ibrahim S. Jawahir
Institute for Sustainable Manufacturing Faculty Publications
Instead of implementing each element individually, engineers must be aware of multiple interactions among all major value creation factors and their life-cycle stages. Interactions are analyzed by a set of factors and hierarchical levels within a production system based on empirical observations and described in analytical models. Such analyses and missing information about the current condition of the system and its parts remain limited to addressing specific aspects of interactions among factors and stages for multiple decision making. To build a case-based scope addressing the interactions among a set of factors and life-cycle stages, a comprehensive approach for mapping and …
Air Exchange Rates And Alternatuve Vapor Entry Pathways To Inform Vapor Intrusion Exposure Risk Assessments, Rivka Reichman, Mohammadyousef Roghani, Evan J. Willett, Elham Shirazi, Kelly G. Pennell
Air Exchange Rates And Alternatuve Vapor Entry Pathways To Inform Vapor Intrusion Exposure Risk Assessments, Rivka Reichman, Mohammadyousef Roghani, Evan J. Willett, Elham Shirazi, Kelly G. Pennell
Civil Engineering Faculty Publications
Vapor intrusion (VI) is a term used to describe indoor air (IA) contamination that occurs due to the migration of chemical vapors in the soil and groundwater. The overall vapor transport process depends on several factors such as contaminant source characteristics, subsurface conditions, building characteristics, and general site conditions. However, the classic VI conceptual model does not adequately account for the physics of airflow around and inside a building and does not account for chemical emissions from alternative “preferential” pathways (e.g. sewers and other utility connections) into IA spaces. This mini-review provides information about recent research related to building air …
Recent Advances On Iron Oxide Magnetic Nanoparticles As Sorbents Of Organic Pollutants In Water And Wastewater Treatment, Angela M. Gutierrez, Thomas D. Dziubla, J. Zach Hilt
Recent Advances On Iron Oxide Magnetic Nanoparticles As Sorbents Of Organic Pollutants In Water And Wastewater Treatment, Angela M. Gutierrez, Thomas D. Dziubla, J. Zach Hilt
Superfund Research Center Faculty Publications
The constant growth in population worldwide over the past decades continues to put forward the need to provide access to safe, clean water to meet human needs. There is a need for cost-effective technologies for water and wastewater treatment that can meet the global demands and the rigorous water quality standards and at the same maximizing pollutant efficiency removal. Current remediation technologies have failed in keeping up with these factors without becoming cost-prohibitive. Most recently, nanotechnology has been sought as the best alternative to increase access to water supplies by remediating those already contaminated and offering ways to access unconventional …
Nitrate Radicals And Biogenic Volatile Organic Compounds: Oxidation, Mechanisms And Organic Aerosol, Nga Lee Ng, Steven S. Brown, Alexander T. Archibald, Elliot Atlas, Ronald C. Cohen, John N. Crowley, Douglas A. Day, Neil M. Donahue, Juliane L. Fry, Hendrik Fuchs, Robert J. Griffin, Marcelo I. Guzman, Hartmut Hermann, Alma Hodzic, Yoshiteru Iinuma, José L. Jimenez, Astrid Kiendler-Scharr, Ben H. Lee, Deborah J. Luecken, Jingqiu Mao, Robert Mclaren, Anke Mutzel, Hans D. Osthoff, Bin Ouyang, Benedicte Picquet-Varrault, Ulrich Platt, Havala O. T. Pye, Yinon Rudich, Rebecca H. Schwantes, Manabu Shiraiwa, Jochen Stutz, Joel A. Thornton, Andreas Tilgner, Brent J. Williams, Rahul A. Zaveri
Nitrate Radicals And Biogenic Volatile Organic Compounds: Oxidation, Mechanisms And Organic Aerosol, Nga Lee Ng, Steven S. Brown, Alexander T. Archibald, Elliot Atlas, Ronald C. Cohen, John N. Crowley, Douglas A. Day, Neil M. Donahue, Juliane L. Fry, Hendrik Fuchs, Robert J. Griffin, Marcelo I. Guzman, Hartmut Hermann, Alma Hodzic, Yoshiteru Iinuma, José L. Jimenez, Astrid Kiendler-Scharr, Ben H. Lee, Deborah J. Luecken, Jingqiu Mao, Robert Mclaren, Anke Mutzel, Hans D. Osthoff, Bin Ouyang, Benedicte Picquet-Varrault, Ulrich Platt, Havala O. T. Pye, Yinon Rudich, Rebecca H. Schwantes, Manabu Shiraiwa, Jochen Stutz, Joel A. Thornton, Andreas Tilgner, Brent J. Williams, Rahul A. Zaveri
Chemistry Faculty Publications
Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 decades, during which time a large body of research has emerged from laboratory, field, and modeling studies. NO3-BVOC reactions influence air quality, climate and visibility through regional and global budgets for reactive nitrogen (particularly organic nitrates), ozone, and organic aerosol. Despite its long history of research and the significance of this topic in atmospheric chemistry, a number …
Contemporary And Future Characteristics Of Precipitation Indices In The Kentucky River Basin, Somsubhra Chattopadhyay, Dwayne R. Edwards, Yao Yu
Contemporary And Future Characteristics Of Precipitation Indices In The Kentucky River Basin, Somsubhra Chattopadhyay, Dwayne R. Edwards, Yao Yu
Biosystems and Agricultural Engineering Faculty Publications
Climatic variability can lead to large-scale alterations in the hydrologic cycle, some of which can be characterized in terms of indices involving precipitation depth, duration and frequency. This study evaluated the spatiotemporal behavior of precipitation indices over the Kentucky River watershed for both the baseline period of 1986–2015 and late-century time frame of 2070–2099. Historical precipitation data were collected from 16 weather stations in the watershed, while future rainfall time-series were obtained from an ensemble of 10 Coupled Model Intercomparison Project Phase 5 (CMIP5) global circulation models under two future emission pathways: Representative Concentration Pathways (RCP) 4.5 and 8.5. Annual …
Us Residential Building Air Exchange Rates: New Perspectives To Improve Decision Making At Vapor Intrusion Sites, Rivka Reichman, Elham Shirazi, Donald G. Colliver, Kelly G. Pennell
Us Residential Building Air Exchange Rates: New Perspectives To Improve Decision Making At Vapor Intrusion Sites, Rivka Reichman, Elham Shirazi, Donald G. Colliver, Kelly G. Pennell
Civil Engineering Faculty Publications
Vapor intrusion (VI) is well-known to be difficult to characterize because indoor air (IA) concentrations exhibit considerable temporal and spatial variability in homes throughout impacted communities. To overcome this and other limitations, most VI science has focused on subsurface processes; however there is a need to understand the role of aboveground processes, especially building operation, in the context of VI exposure risks. This tutorial review focuses on building air exchange rates (AERs) and provides a review of literature related building AERs to inform decision making at VI sites. Commonly referenced AER values used by VI regulators and practitioners do not …
Fischer–Tropsch Synthesis: Effect Of Ammonia On Product Selectivities For A Pt Promoted Co/Alumina Catalyst, Venkat Ramana Rao Pendyala, Wilson D. Shafer, Gary Jacobs, Michela Martinelli, Dennis E. Sparks, Burtron H. Davis
Fischer–Tropsch Synthesis: Effect Of Ammonia On Product Selectivities For A Pt Promoted Co/Alumina Catalyst, Venkat Ramana Rao Pendyala, Wilson D. Shafer, Gary Jacobs, Michela Martinelli, Dennis E. Sparks, Burtron H. Davis
Center for Applied Energy Research Faculty and Staff Publications
The effects of co-fed ammonia in synthesis gas on the activity and product selectivities of a typical cobalt catalyst (0.5% Pt–25% Co/Al2O3) were investigated during the Fischer–Tropsch synthesis using a continuously stirred tank reactor (CSTR). The product selectivities were compared at a similar CO conversion level for various concentrations (10–1000 ppmv) of ammonia, as well as clean (un-poisoned) conditions. The addition of 10–1000 ppmv ammonia (concentration of ammonia with respect to the syngas feed) significantly decreased activity; the percentage of deactivation was similar (∼40%) for the various concentrations of ammonia used. At similar CO conversions, the …
Automated Calibration Of Electrochemical Oxygen Sensors For Use In Compost Bedded Pack Barns, John T. Evans, Michael P. Sama, Joseph L. Taraba, George B. Day
Automated Calibration Of Electrochemical Oxygen Sensors For Use In Compost Bedded Pack Barns, John T. Evans, Michael P. Sama, Joseph L. Taraba, George B. Day
Biosystems and Agricultural Engineering Faculty Publications
The objective of this study was to develop an automated calibration process for a galvanic cell type oxygen sensor. The manufacturer recommended a two-point calibration at room temperature; however, testing revealed that the response was not linear when both the temperature and oxygen concentrations varied. Thus, additional points were needed to generate a representative calibration equation and to reduce the sensor prediction interval. The calibration process needed to be capable of automatically recording sensor response (voltage) at an array of temperatures and oxygen concentrations. Calibration gases were used to precisely control the oxygen concentration inside a small manifold, and an …
Ammonia And Carbon Dioxide Emissions Of Three Laying-Hen Housing Systems As Affected By Manure Accumulation Time, Timothy A. Shepherd, Hongwei Xin, John P. Stinn, Morgan D. Hayes, Yang Zhao, Hong Li
Ammonia And Carbon Dioxide Emissions Of Three Laying-Hen Housing Systems As Affected By Manure Accumulation Time, Timothy A. Shepherd, Hongwei Xin, John P. Stinn, Morgan D. Hayes, Yang Zhao, Hong Li
Biosystems and Agricultural Engineering Faculty Publications
Laying-hen housing design and management are the most significant factors affecting the generation and release of gaseous ammonia to the atmosphere. Transitioning the hen housing type from traditional high-rise (where manure is stored within the house for about one year) to modern manure-belt style (where manure is removed every 1 to 4 d and placed into long-term storage) has significantly improved in-barn air quality and reduced farm-level ammonia emissions. As a direct result of the advantages, 100% of new construction for U.S. egg production incorporates manure-belt systems that regularly remove manure from the houses. However, manure-belt system designs (e.g., active …
Assessment Of Potential Impacts To Surface And Subsurface Water Bodies Due To Longwall Mining, Christopher R. Newman, Zacharias Agioutantis, Gabriel Boede Jimenez Leon
Assessment Of Potential Impacts To Surface And Subsurface Water Bodies Due To Longwall Mining, Christopher R. Newman, Zacharias Agioutantis, Gabriel Boede Jimenez Leon
Mining Engineering Faculty Publications
Ground movements due to longwall mining operations have the potential to damage the hydrological balance within as well as outside the mine permit area in the form of increased surface ponding and changes to hydrogeological properties. Recently, the Office of Surface Mining, Reclamation and Enforcement (OSMRE) in the USA, has completed a public comment period on a newly proposed rule for the protection of streams and groundwater from adverse impacts of surface and underground mining operations (80 FR 44435). With increased community and regulatory focus on mining operations and their potential to adversely affect streams and groundwater, now there is …
Evaluation Of Flocculation, Sedimentation, And Filtration For Dewatering Of Scenedesmus Algae, Nicholas A. Rhea, Jack Groppo, Czarena Crofcheck
Evaluation Of Flocculation, Sedimentation, And Filtration For Dewatering Of Scenedesmus Algae, Nicholas A. Rhea, Jack Groppo, Czarena Crofcheck
Biosystems and Agricultural Engineering Faculty Publications
Algae can be used as a feedstock for agricultural fertilizers, livestock and poultry feeds, anaerobic digestion, and biofuel production. For each end product, the requirements for moisture content (or solids content) vary, such that a desirable water removal strategy needs to be adaptable to varying levels of water removal. Flocculation, sedimentation, and filtration were evaluated as possible strategies for thickening and dewatering of algae. The goal of this study was to validate that algae cells treated by such means could be processed by vacuum belt filters and to determine the conditions under which the solids content could be increased to …