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Reduction of Air Pollutants from Gas Burner Flames: Including Related Reaction Kinetics

Description: From Abstract: "The concentrations of air pollutants and the flame temperatures were measured, and the effects of ingress of secondary air into the primary and secondary combustion zones, flame stability, burner port surface, and simulated recycling of combustion gases were noted."
Date: unknown
Creator: Harris, Margaret E.; Rowe, Valeria R.; Cook, E. B. & Grumer, J.
Partner: UNT Libraries Government Documents Department

Summary for Policy-makers

Description: Report summarizing the policy-relevant findings of the Arctic Monitoring and Assessment Programme' 2015 assessments of short-lived climate pollutants (Methane, Black carbon, and Ozone).
Date: May 23, 2016
Creator: Arctic Monitoring and Assessment Programme
Partner: UNT Libraries Government Documents Department

Evaluating Chemical Persistence in a Multimedia Environment: ACART Analysis

Description: For the thousands of chemicals continuously released into the environment, it is desirable to make prospective assessments of those likely to be persistent. Persistent chemicals are difficult to remove if adverse health or ecological effects are later discovered. A tiered approach using a classification scheme and a multimedia model for determining persistence is presented. Using specific criteria for persistence, a classification tree is developed to classify a chemical as ''persistent'' or ''non-persistent'' based on the chemical properties. In this approach, the classification is derived from the results of a standardized unit world multimedia model. Thus, the classifications are more robust for multimedia pollutants than classifications using a single medium half-life. The method can be readily implemented and provides insight without requiring extensive and often unavailable data. This method can be used to classify chemicals when only a few properties are known and be used to direct further data collection. Case studies are presented to demonstrate the advantages of the approach.
Date: February 1, 1999
Creator: Bennett, D.H.; McKone, T.E. & Kastenberg, W.E.
Partner: UNT Libraries Government Documents Department

Trends in Stockholm Convention Persistent Organic Pollutants (POPs) in Arctic Air, Human media and Biota

Description: This report summarizes results of the Persistent Organic Pollutants (POPs) (temporal) trend monitoring studies conducted under the auspices of the Arctic Monitoring and Assessment Programme (AMP) that are relevant to the Stockholm Convention
Date: 2014
Creator: Arctic Monitoring and Assessment Programme
Partner: UNT Libraries Government Documents Department

Analysis of Ambient Pollutant Concentrations and Meteorological Conditions Affecting EPA Class I and II Areas in Southeastern Louisiana, Volume 2: Appendices

Description: Appendices containing data that was collected as apart of a study on pollutants in Southeastern Louisiana. The four appendices include: [A] Gosier Island Hourly Data, [B] Breton Island (Chandeleur Islander) Hourly Data, [C] Pass-A-Loutre Hourly Data, and [D] Radiosonde Data.
Date: December 1996
Creator: Hsu, S. A.
Partner: UNT Libraries Government Documents Department

Accepted Limit Values of Air Pollutants

Description: Report issued by the U.S. Bureau of Mines discussing, as stated in the introduction, the "accepted maximum permissible concentrations of air pollutants from the standpoints of health, damage to vegetation, damage to property, and requirements of industrial processes" (p. 1). This report includes tables.
Date: May 1954
Creator: Barkley, J. F.
Partner: UNT Libraries Government Documents Department

Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks

Description: Emission factors for black carbon (BC) and particle number (PN) were measured from 226 individual heavy-duty (HD) diesel-fueled trucks driving through a 1 km-long California highway tunnel in August 2006. Emission factors were based on concurrent increases in BC, PN, and CO{sub 2}B concentrations (measured at 1 Hz) that corresponded to the passage of individual HD trucks. The distributions of BC and PN emission factors from individual HD trucks are skewed, meaning that a large fraction of pollution comes from a small fraction of the in-use vehicle fleet. The highest-emitting 10% of trucks were responsible for {approx} 40% of total BC and PN emissions from all HD trucks. BC emissions were log-normally distributed with a mean emission factor of 1.7 g kg {sup -1} and maximum values of {approx} 10 g kg{sup -1}. Corresponding values for PN emission factors were 4.7 x 10{sup 15} and 4 x 10{sup 16} kg{sup -1}. There was minimal overlap among high-emitters of these two pollutants: only 1 of the 226 HD trucks measured was found to be among the highest 10% for both BC and PN. Monte Carlo resampling of the distribution of BC emission factors observed in this study revealed that uncertainties (1{sigma}) in extrapolating from a random sample of n HD trucks to a population mean emission factor ranged from {+-} 43% for n = 10 to {+-} 8% for n = 300, illustrating the importance of sufficiently large vehicle sample sizes in emissions studies. Studies with low sample sizes are also more easily biased due to misrepresentation of high-emitters. As vehicles become cleaner on average in future years, skewness of the emissions distributions will increase, and thus sample sizes needed to extrapolate reliably from a subset of vehicles to the entire in-use vehicle fleet are expected to become more of a ...
Date: February 2, 2009
Creator: Ban-Weiss, George A.; Lunden, Melissa M.; Kirchstetter, Thomas W. & Harley, Robert A.
Partner: UNT Libraries Government Documents Department

Deprivation of Equations Describing Solute Transport in Ground Water

Description: Abstract: A general equation describing the three-dimensional transport and dispersion of a reacting solute in flowing ground water is derived from the principle of conservation of mass. The derivation presented in this report is more detailed but less rigorous than derivations published previously. The general solute-transport equation relates concentration changes to hydrodynamic dispersion, convective transport, fluid sources and sinks, and chemical reactions. Because both dispersion and convective transport depend on the velocity of ground-water flow, the solute-transport equation must be solved in conjunction with the ground-water flow equation.
Date: April 1977
Creator: Konikow, Leonard F. & Grove, David B.
Partner: UNT Libraries Government Documents Department

A model for simulating airflow and pollutant dispersion around buildings

Description: A three-dimensional, numerical mode1 for simulating airflow and pollutant dispersion around buildings is described. The model is based on an innovative finite element approach and fully implicit time integration techniques. Linear and nonlinear eddy viscosity/diffusivity submodels are provided for turbulence parameterization. Mode1 predictions for the flow-field and dispersion patterns around a surface-mounted cube are compared with measured data from laboratory experiments.
Date: February 24, 1999
Creator: Chan, S T & Lee, R L
Partner: UNT Libraries Government Documents Department

Indoor pollutant mixing time in an isothermal closed room: An investigation using CFD

Description: We report on computational fluid dynamics (CFD) predictions of mixing time of a pollutant in an unventilated, mechanically mixed, isothermal room. The study aims to determine: (1) the adequacy of the standard Reynolds Averaged Navier Stokes two-equation ({kappa}-{var_epsilon}) turbulence model for predicting the mixing time under these conditions and (2) the extent to which the mixing time depends on the room airflow, rather than the source location within the room. The CFD simulations modeled the 12 mixing time experiments performed by Drescher et al. (Indoor Air 5 (1995) 204) using a point pulse release in an isothermal, sealed room mechanically mixed with variable power blowers. Predictions of mixing time were found in good agreement with experimental measurements, over an order of magnitude variation in blower power. Additional CFD simulations were performed to investigate the relation between pollutant mixing time and source location. Seventeen source locations and five blower configurations were investigated. Results clearly show large dependence of the mixing time on the room airflow, with some dependence on source location. We further explore dependence of mixing time on the velocity and turbulence intensity at the source location. Implications for positioning air-toxic sensors in rooms are briefly discussed.
Date: July 1, 2003
Creator: Gadgil, A.J.; Lobscheid, C.; Abadie, M.O. & Finlayson, E.U.
Partner: UNT Libraries Government Documents Department

Passive measurement of nitrogen oxides to assess traffic-related pollutant exposure for the East Bay Children's Respiratory Health Study

Description: This paper provides an overview of software interoperability as it relates to the energy simulation of buildings. The paper begins with a discussion of the difficulties in using sophisticated analysis tools like energy simulation at various stages in the building life cycle, and the potential for interoperability to help overcome these difficulties. An overview of the Industry Foundation Classes (IFC), a common data model for supporting interoperability under continuing development by the International Alliance for Interoperability (IAI) is then given. The process of creating interoperable software is described next, followed by specific details for energy simulation tools. The paper closes with the current status of, and future plans for, the ongoing efforts to achieve software interoperability.
Date: September 1, 2003
Creator: Singer, Brett C.; Hodgson, Alfred T.; Hotchi, Toshifumi & Kim, Janice J.
Partner: UNT Libraries Government Documents Department

Life that really is down under

Description: The story begins in the early 1980`s, when it was recognized that fundamental science about deep aquifers (greater than 30 feet below the surface) was virtually non existent. If population centers were to continue to expand, the understanding of these deep reservoirs of life-giving water was essential. Over 53% of the US population receives its drinking water from wells, yet these sources continue to be polluted by government, industrial and private sources. If microorganism, life too small to be seen except through powerful microscopes, were present underground, then maybe they could help return polluted groundwaters to wholesome quality. Such was the vision in the Office of Health and Environmental Research at DOE that spawned the Microbiology of the Deep Subsurface Program.
Date: Spring 1988
Creator: Fliermans, C.
Partner: UNT Libraries Government Documents Department

Rebuilding the World with Green BRICs

Description: Poster presentation for the 2010 University Scholars Day at the University of North Texas. This poster discusses social, economic, and global issues and research on rebuilding the world with green, energy-efficient strategies for Brazil, Russia, India, and China (BRIC).
Date: April 15, 2010
Creator: Hubby, Desiree & Engen, Ryan
Partner: UNT Honors College

Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, and Visualization methods with Applications to Site Characterization

Description: The Department of Energy has identified the location and characterization of subsurface contaminants and the charcterization of the subsurface as a priority need. Many DOE facilities are in need of subsurface imaging in the vadose and saturated zones.
Date: October 7, 2006
Creator: Wright, David; Olhoeft, Michael Powers / gary; Oden, Charles & Moulton, Craig
Partner: UNT Libraries Government Documents Department

Hanford Site Environmental Surveillance Master Sampling Schedule

Description: Environmental surveillance of the Hanford Site and surrounding areas is conducted by Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE). Sampling is conducted to evaluate levels of radioactive and nonradioactive pollutants in the Hanford environs. The document contains the CY 2002 schedules for the routine collection of samples for the Surface Environmental Surveillance Project (SESP) and Drinking Water Monitoring Project.
Date: January 16, 2002
Creator: Bisping, Lynn E.
Partner: UNT Libraries Government Documents Department

Policy-makers Summary: Arctic Pollution Issues 2015

Description: This document presents the policy-makers summary of the 2015 AMAP Assessments of Pollution Issues (POPs Trends; Radioactivity in the Arctic; Human Health in the Arctic). More detailed information on the results of the assessments can be found in the related Scientific Assessment Reports.
Date: 2015
Creator: Arctic Monitoring and Assessment Programme
Partner: UNT Libraries Government Documents Department

Understanding Microbial Biodegradation of Environmental Contaminants

Description: The accumulation of industrial contaminants in the natural environments have rapidly become a serious threat for human and animal life. Fortunately, there are microorganisms capable of degrading or transforming environmental contaminants. The present dissertation work aimed to understand the genomic basis of microbial degradation and resistance. The focus was the genomic study of the following bacteria: a) Pseudomonas fluorescens NCIMB 11764, a unique bacterium with specific enzymes that allow cyanide adaptation features. Potential cyanide degradation mechanisms found in this strain included nit1C cluster, and CNO complex. Potential cyanide tolerance genes found included cyanide insensitive oxidases, nitric oxide producing gene, and iron metabolism genes. b) Cupriavidus sp. strain SK-3 and strain SK-4. The genome of both bacteria presented the bph operon for polychlorinated biphenyl (PCB) degradation, but we found differences in the sequences of the genes. Those differences might indicate their preferences for different PCB substrates. c) Arsenic resistant bacterial communities observed in the Atacama Desert. Specific bacteria were found to thrive depending on the arsenic concentration. Examples were Bacteroidetes and Spirochaetes phyla whose proportions increased in the river with high arsenic concentrations. Also, DNA repair and replication metabolic functions seem to be necessary for resistance to arsenic contaminated environments. Our research give us insights on how bacteria communities, not just individually, can adapt and become resistant to the contaminants. The present dissertation work showed specific genes and mechanisms for degradation and resistance of contaminants that could contribute to develop new bioremediation strategies.
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Date: May 2015
Creator: Vilo Muñoz, Claudia Andrea
Partner: UNT Libraries

Interbasin Flux Measurements Using Simple Methods

Description: The Vertical Transport and Mixing (VTMX) campaign, sponsored by the US Department of Energy, took place in the Salt Lake Valley during October, 2000. The purpose of VTMX was to further understanding of meteorological processes that govern vertical transport and mixing in complex terrain, particularly during nocturnal stable periods and their morning and evening transition periods. These meteorological processes were the subject of numerous sponsored studies during VTMX. The Salt Lake (Salt Lake City) Basin and the Utah Basin to its south are separated by the Traverse Range. Near-surface airflow between the basins is channeled through the Jordan Narrows, also the channel for the Jordan River that flows from the Utah Basin into Salt Lake via the Salt Lake Basin. Jordan Narrows is thus a potentially significant corridor for pollutant transport between the two basins. This paper describes simple and direct pollutant (PM{sub 10}) measurements, with concurrent continuous meteorological monitoring, to characterize pollutant transport between the two basins via low-level stable nocturnal drainage flow, with an emphasis on its vertical variability when mixing is limited. The Jordan Narrows has similarities to other transport corridors where direct in-corridor monitoring of pollutant flux might enhance pollution forecasts during transport conditions. Thus their more general objective is to assess the usefulness of direct methods to characterize pollutant flux in similar environments.
Date: January 13, 2005
Creator: Watson, John & Freeman, Daniel
Partner: UNT Libraries Government Documents Department

Short-lived pollutants in the Arctic: their climate impact and possible mitigation strategies

Description: Several short-lived pollutants known to impact Arctic climate may be contributing to the accelerated rates of warming observed in this region relative to the global annually averaged temperature increase. Here, we present a summary of the short-lived pollutants that impact Arctic climate including methane, tropospheric ozone, and tropospheric aerosols. For each pollutant, we provide a description of the major sources and the mechanism of forcing. We also provide the first seasonally averaged forcing and corresponding temperature response estimates focused specifically on the Arctic. The calculations indicate that the forcings due to black carbon, methane, and tropospheric ozone lead to a positive surface temperature response indicating the need to reduce emissions of these species within and outside the Arctic. Additional aerosol species may also lead to surface warming if the aerosol is coincident with thin, low lying clouds. We suggest strategies for reducing the warming based on current knowledge and discuss directions for future research to address the large remaining uncertainties.
Date: September 24, 2007
Creator: Menon, Surabi; Quinn, P.K.; Bates, T.S.; Baum, E.; Doubleday, N.; Fiore, A.M. et al.
Partner: UNT Libraries Government Documents Department