Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in Mexico City (open access)

Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in Mexico City

This project was one of three collaborating grants designed to understand the atmospheric chemistry and aerosol particle microphysics impacting air quality in the Mexico City Metropolitan Area (MCMA) and its urban plume. The overall effort, titled MCMA- 2006, focused on: 1) the primary emissions of fine particles and precursor gases leading to photochemical production of atmospheric oxidants and secondary aerosol particles and 2) the measurement and analysis of secondary oxidants and secondary fine particular matter (PM) production, with particular emphasis on secondary organic aerosol (SOA). MCAM-2006 pursued it goals through three main activities: 1) performance and publication of detailed analyses of extensive MCMA trace gas and fine PM measurements made by the collaborating groups and others during earlier MCMA field campaigns in 2002 and 2003; 2) deployment and utilization of extensive real-time trace gas and fine PM instrumentation at urban and downwind MCMA sites in support of the MAX-Mex/MILAGRO field measurements in March, 2006; and, 3) analyses of the 2006 MCMA data sets leading to further publications that are based on new data as well as insights from analysis and publication of the 2002/2003 field data. Thirteen archival publications were coauthored with other MCMA-2003 participants. Documented findings included a significantly …
Date: March 31, 2008
Creator: Zavala, Dr. Charles E. Kolb Dr. Douglas R. Worsnop Dr. Manjula R. Canagaratna Dr. Scott C. Herndon Dr. John T. Jayne Dr. W. Berk Knighton Dr. Timothy B. Onasch Dr. Ezra C. Wood Dr. Miguel
Object Type: Report
System: The UNT Digital Library
Characterization of shape memory alloys for safety mechanisms. (open access)

Characterization of shape memory alloys for safety mechanisms.

Shape memory alloys (SMAs) are metals that exhibit large recoverable strains and exert large forces with tremendous energy densities. The behavior of SMAs is thermomechanically coupled. Their response to temperature is sensitive to their loading condition and their response to loading is sensitive to their thermal condition. This coupled behavior is not to be circumvented, but to be confronted and understood, since it is what manifests SMA's superior clamping performance. To reasonably characterize the coupled behavior of SMA clamping rings used in safety mechanisms, we conduct a series of experiments on SMA samples. The results of the tests will allow increased fidelity in modeling and failure analysis of parts.
Date: March 1, 2008
Creator: McLaughlin, Jarred T.; Buchheit, Thomas Edward & Massad, Jordan Elias
Object Type: Report
System: The UNT Digital Library
Characterization Studies and Performance of Half-strip High-speed X-ray Microchannel Plate Imager (open access)

Characterization Studies and Performance of Half-strip High-speed X-ray Microchannel Plate Imager

High-speed microchannel plate (MCP)–based imagers are critical detectors for x-ray diagnostics employed on Z-experiments at Sandia National Laboratories (SNL) to measure time-resolved x-ray spectra and to image dynamic hohlraums. A design using eight half-strip x-ray photocathodes in one imager permits recordings of radiation events in discrete temporal snapshots to yield a time-evolved movie. We present data using various facilities to characterize the performance of this design. These characterization studies include DC and pulsed-voltage biased measurements in both saturated and linear operational regimes using an intense, short-pulsed UV laser and Manson source. Surface voltage profile measurements using a picoprobe help to determine the gain variation across the strips. Test data from a recent SNL ZR-experiment demonstrates the flexibility and high-quality images obtained by this MCP imager.
Date: March 1, 2008
Creator: Moy, Kenneth & Wu, Ming
Object Type: Article
System: The UNT Digital Library
Check-Testing of Manufacturer Self Reported Labeling Data & Compliance with MEPS (open access)

Check-Testing of Manufacturer Self Reported Labeling Data & Compliance with MEPS

China first adopted minimum energy performance standards (MEPS) in 1989. Today, there are standards for a wide range of domestic, commercial and selected industrial equipment. In 1999, China launched a voluntary endorsement label, which has grown to cover over 40 products including water-saving products. Further, in 2005, China started a mandatory energy information label that initially covered two products and in 2007 was extended to cover four products total including: air conditioners; household refrigerators; clothes washers; and unitary air conditioners. These programs have had an important impact in reducing the energy consumption of appliances in China. China has built up a strong infrastructure to develop and implement standards. Historically, however, the government's primary focus has been on the technical requirements for specifying efficiency performance. Less attention has been paid to monitoring and enforcement with a minimal commitment of resources and little expansion of administrative capacity in this area. Thus, market compliance with both mandatory standard and labeling programs has been questionable. Furthermore, actual energy savings have quite possibly been undermined as a result. The establishment of a regularized monitoring system for tracking compliance with the mandatory standard and energy information label programs in China is a major area for program …
Date: March 1, 2008
Creator: Zhou, Nan; Zhou, Nan; Zheng, Nina; Fridley, David; Wang, Ruohong & Egan, Christine
Object Type: Report
System: The UNT Digital Library
Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy (open access)

Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy

To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.
Date: March 29, 2008
Creator: Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko & Denlinger, Jonathan D.
Object Type: Article
System: The UNT Digital Library
Chemical Assessments: Low Productivity and New Interagency Review Process Limit the Usefulness and Credibility of EPA's Integrated Risk Information System (open access)

Chemical Assessments: Low Productivity and New Interagency Review Process Limit the Usefulness and Credibility of EPA's Integrated Risk Information System

A letter report issued by the Government Accountability Office with an abstract that begins "The Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) contains EPA's scientific position on the potential human health effects of exposure to more than 540 chemicals. IRIS is a critical component of EPA's capacity to support scientifically sound environmental decisions, policies, and regulations. GAO was asked to examine (1) the outcome of steps EPA has taken to ensure that IRIS contains current, credible chemical risk information, to address the backlog of ongoing assessments, and to respond to new requirements from the Office of Management and Budget (OMB); and (2) the potential effects of planned changes to the IRIS assessment process on EPA's ability to ensure that IRIS provides current, credible risk information. To do this work, GAO reviewed and analyzed EPA data and interviewed officials at relevant agencies."
Date: March 7, 2008
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Chemical Regulation in the European Union: Registration, Evaluation, and Authorization of Chemicals (open access)

Chemical Regulation in the European Union: Registration, Evaluation, and Authorization of Chemicals

This report discusses a new law, Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH), that the European Union (EU) began to implement On June 1, 2007.
Date: March 19, 2008
Creator: Schierow, Linda-Jo
Object Type: Report
System: The UNT Digital Library
Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from Marine Boundary Layer over the California Current (open access)

Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from Marine Boundary Layer over the California Current

Detailed chemical speciation of the dry residue particles from individual cloud droplets and interstitial aerosol collected during the Marine Stratus Experiment (MASE) was performed using a combination of complementary microanalysis techniques. Techniques include computer controlled scanning electron microscopy with energy dispersed analysis of X-rays (CCSEM/EDX), time-of-flight secondary ionization mass spectrometry (TOF-SIMS), and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Samples were collected at the ground site located in Point Reyes National Seashore, approximately 1 km from the coast. This manuscript focuses on the analysis of individual particles sampled from air masses that originated over the open ocean and then passed through the area of the California current located along the northern California coast. Based on composition, morphology, and chemical bonding information, two externally mixed, distinct classes of sulfur containing particles were identified: chemically modified (aged) sea salt particles and secondary formed sulfate particles. The results indicate substantial heterogeneous replacement of chloride by methanesulfonate (CH3SO3-) and non-sea salt sulfate (nss-SO42-) in sea-salt particles with characteristic ratios of nss-S/Na>0.10 and CH3SO3-/nss-SO42->0.6.
Date: March 12, 2008
Creator: William R. Wiley Environmental Sciences Laboratory, Pacific Northwest National Laboratory; Gilles, Mary K; Hopkins, Rebecca J.; Desyaterik, Yury; Tivanski, Alexei V.; Zaveri, Rahul A. et al.
Object Type: Article
System: The UNT Digital Library
China and Proliferation of Weapons of Mass Destruction and Missiles: Policy Issues (open access)

China and Proliferation of Weapons of Mass Destruction and Missiles: Policy Issues

This report discusses the national security problem of China's role in weapons proliferation and issues related to the U.S. policy response, including legislation, since the mid-1990's.
Date: March 6, 2008
Creator: Kan, Shirley A.
Object Type: Report
System: The UNT Digital Library
China-U.S. Relations: Current Issues and Implications for U.S. Policy (open access)

China-U.S. Relations: Current Issues and Implications for U.S. Policy

This report mainly focuses on Current Issues and Implications for U.S. Policy of China-U.S. Relations.U.S relations with China remarkably smooth from 2001-2004 have shown signs of becoming somewhat more problematic again since 2005 as some U.S policymakers.
Date: March 17, 2008
Creator: Dumbaugh, Kerry
Object Type: Report
System: The UNT Digital Library
China-U.S. Trade Issues (open access)

China-U.S. Trade Issues

This report examines the major U.S. - China trade issues.
Date: March 7, 2008
Creator: Morrison, Wayne M.
Object Type: Report
System: The UNT Digital Library
China’s Economic Conditions (open access)

China’s Economic Conditions

This report discusses China’s Economic Conditions.
Date: March 11, 2008
Creator: Morrison, Wayne M.
Object Type: Report
System: The UNT Digital Library
Citizen Handbook on Superfund in Texas (open access)

Citizen Handbook on Superfund in Texas

Handbook answering questions related to Superfund program in regards to contaminated sites, environmental agencies, and cleanup.
Date: March 2008
Creator: Texas Commission on Environmental Quality
Object Type: Pamphlet
System: The Portal to Texas History
Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems (open access)

Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems

Fenton's reagent, a solution of hydrogen peroxide and ferrous iron catalyst, is used for an in-situ chemical oxidation of organic contaminants. Sulfuric acid is commonly used to create an acidic condition needed for catalytic oxidation. Fenton's reaction often involves pressure buildup and precipitation of reaction products, which can cause safety hazards and diminish efficiency. We selected citric acid, a food-grade substance, as an acidifying agent to evaluate its efficiencies for organic contaminant removal in Fenton's reaction, and examined the impacts of using citric acid on the unwanted reaction products. A series of batch and column experiments were performed with varying H{sub 2}O{sub 2} concentrations to decompose selected chlorinated ethylenes. Either dissolved iron from soil or iron sulfate salt was added to provide the iron catalyst in the batch tests. Batch experiments revealed that both citric and sulfuric acid systems achieved over 90% contaminant removal rates, and the presence of iron catalyst was essential for effective decontamination. Batch tests with citric acid showed no signs of pressure accumulation and solid precipitations, however the results suggested that an excessive usage of H{sub 2}O{sub 2} relative to iron catalysts (Fe{sup 2+}/H{sub 2}O{sub 2} < 1/330) would result in lowering the efficiency of contaminant …
Date: March 15, 2008
Creator: Seol, Yongkoo & Javandel, Iraj
Object Type: Article
System: The UNT Digital Library
Clean Air Issues in the 110th Congress: Climate Change, Air Quality Standards, and Oversight (open access)

Clean Air Issues in the 110th Congress: Climate Change, Air Quality Standards, and Oversight

This report provides a brief overview of the climate change issue as well as other Clean Air Act issues of interest in the 110th Congress.
Date: March 7, 2008
Creator: McCarthy, James E.
Object Type: Report
System: The UNT Digital Library
Clean Air Permitting: Status of Implementation and Issues (open access)

Clean Air Permitting: Status of Implementation and Issues

This report describes the statutory background of the Title V program and the status of implementation, in terms of federal approval of state and local permitting authorities and permit issuance. It also discusses broad policy issues identified by various stakeholders, including program complexity and costs, and inconsistencies due to a lack of sufficient federal guidance.
Date: March 20, 2008
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
Clean Water Act: A Summary of the Law (open access)

Clean Water Act: A Summary of the Law

This report presents a summary of the law, describing the essence of the statute without discussing its implementation. Other CRS products do discuss implementation, including CRS Report RL33800, Water Quality Issues in the 110th Congress: Oversight and Implementation, and numerous products cited in that report.
Date: March 17, 2008
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
Clean Water Act Section 401: Background and Issues (open access)

Clean Water Act Section 401: Background and Issues

Report discussing specifics of the U.S. Clean Water Act. Section 401 of the Clean Water Act requires that an applicant for a federal license or permit provide a certification that any discharges from the facility will comply with the act, including water quality standard requirements. Disputes have arisen over the states' exercise of authority under Section 401. For the most part, the debate over the Section 401 certification issue has been between states and hydropower interests.
Date: March 20, 2008
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
Cleanup Verification Package for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils (open access)

Cleanup Verification Package for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils

This cleanup verification package documents completion of remedial action, sampling activities, and compliance with cleanup criteria for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils. The rectangular-shaped concrete basin on the south side of the 105-F Reactor building served as an underwater collection, storage, and transfer facility for irradiated fuel elements discharged from the reactor.
Date: March 18, 2008
Creator: Habel, L. D.
Object Type: Report
System: The UNT Digital Library
Clerk of the House: Legislative and Administrative Duties (open access)

Clerk of the House: Legislative and Administrative Duties

This report discusses legislative and administrative duties related to Clerk of the House.
Date: March 10, 2008
Creator: Tong, Lorraine H.
Object Type: Report
System: The UNT Digital Library
Climate Change: Science Update 2007 (open access)

Climate Change: Science Update 2007

This report summarizes highlights of new scientific research and assessments released in 2007 related to global warming.
Date: March 12, 2008
Creator: Leggett, Jane A.
Object Type: Report
System: The UNT Digital Library
Closure Strategy for a Waste Disposal Facility with Multiple Waste Types and Regulatory Drivers at the Nevada Test Site (open access)

Closure Strategy for a Waste Disposal Facility with Multiple Waste Types and Regulatory Drivers at the Nevada Test Site

The U.S. Department of Energy, National Security Administration Nevada Site Office (NNSA/NSO) is planning to close the 92-Acre Area of the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS), which is about 65 miles northwest of Las Vegas, Nevada. Closure planning for this facility must take into account the regulatory requirements for a diversity of waste streams, disposal and storage configurations, disposal history, and site conditions. This paper provides a brief background of the Area 5 RWMS, identifies key closure issues, and presents the closure strategy. Disposals have been made in 25 shallow excavated pits and trenches and 13 Greater Confinement Disposal (GCD) boreholes at the 92-Acre Area since 1961. The pits and trenches have been used to dispose unclassified low-level waste (LLW), low-level mixed waste (LLMW), and asbestiform waste, and to store classified low-level and low-level mixed materials. The GCD boreholes are intermediate-depth disposal units about 10 feet (ft) in diameter and 120 ft deep. Classified and unclassified high-specific activity LLW, transuranic (TRU), and mixed TRU are disposed in the GCD boreholes. TRU waste was also disposed inadvertently in trench T-04C. Except for three disposal units that are active, all pits and trenches are …
Date: March 1, 2008
Creator: Desotell, L.; Wieland, D.; Yucel, V.; Shott, G. & Wrapp, J.
Object Type: Article
System: The UNT Digital Library
CO2 Separation Using Thermally Optimized Membranes: A Comprehensive Project Report (2000 - 2007) (open access)

CO2 Separation Using Thermally Optimized Membranes: A Comprehensive Project Report (2000 - 2007)

This is a complete (Fiscal Years 2000–2006) collection of the Idaho National Laboratory’s (INL) research and development contributions to the project, “CO2 Separation Using Thermally Optimized Membranes.” The INL scientific contribution to the project has varied due to the fluctuations in funding from year to year. The focus of the project was polybenzimidazole (PBI) membranes and developing PBI compounds (both substitution and blends) that provide good film formation and gas separation membranes. The underlying problem with PBI is its poor solubility in common solvents. Typically, PBI is dissolved in “aggressive” solvents, like N,N-dimethylacetamide (DMAc) and N methylpyrrolidone (NMP). The INL FY-03 research was directed toward making soluble N-substituted PBI polymers, where INL was very successful. Many different types of modified PBI polymers were synthesized; however, film formation proved to be a big problem with both unsubstituted and N-substituted PBIs. Therefore, INL researchers directed their attention to using plasticizers or additives to make the membranes more stable and workable. During the course of these studies, other high-performance polymers (like polyamides and polyimides) were found to be better materials, which could be used either by themselves or blends with PBI. These alternative high-performance polymers provided the best pathway forward for soluble high-temperature …
Date: March 4, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
CO2 Separation Using Thermally Optimized Membranes: A Comprehensive Project Report (2000 - 2007) (open access)

CO2 Separation Using Thermally Optimized Membranes: A Comprehensive Project Report (2000 - 2007)

This is a complete (Fiscal Years 2000–2006) collection of the Idaho National Laboratory’s (INL) research and development contributions to the project, “CO2 Separation Using Thermally Optimized Membranes.” The INL scientific contribution to the project has varied due to the fluctuations in funding from year to year. The focus of the project was polybenzimidazole (PBI) membranes and developing PBI compounds (both substitution and blends) that provide good film formation and gas separation membranes. The underlying problem with PBI is its poor solubility in common solvents. Typically, PBI is dissolved in “aggressive” solvents, like N,N-dimethylacetamide (DMAc) and N methylpyrrolidone (NMP). The INL FY-03 research was directed toward making soluble N-substituted PBI polymers, where INL was very successful. Many different types of modified PBI polymers were synthesized; however, film formation proved to be a big problem with both unsubstituted and N-substituted PBIs. Therefore, INL researchers directed their attention to using plasticizers or additives to make the membranes more stable and workable. During the course of these studies, other high-performance polymers (like polyamides and polyimides) were found to be better materials, which could be used either by themselves or blends with PBI. These alternative high-performance polymers provided the best pathway forward for soluble high-temperature …
Date: March 1, 2008
Creator: Klaehn, J. R.; Orme, C. J.; Peterson, E. S.; Luther, T. A.; Jones, M. G. & Wertsching, A. K.
Object Type: Report
System: The UNT Digital Library