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Secondary Pollutants from Ozone Reaction with Ventilation Filters and Degradation of Filter Media Additives

Description: Prior research suggests that chemical processes taking place on the surface of particle filters employed in buildings may lead to the formation of harmful secondary byproducts. We investigated ozone reactions with fiberglass, polyester, cotton/polyester and polyolefin filter media, as well as hydrolysis of filter media additives. Studies were carried out on unused media, and on filters that were installed for 3 months in buildings at two different locations in the San Francisco Bay Area. Specim… more
Date: May 1, 2011
Creator: Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jérémie et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Multifilter Rotating Shadowband Radiometer (MFRSR) Handbook

Description: The visible Multifilter Rotating Shadowband Radiometer (MFRSR) is a passive instrument that measures global and diffuse components of solar irradiance at six narrowband channels and one open, or broadband, channel (Harrison et al. 1994). Direct irradiance is not a primary measurement, but is calculated using the diffuse and global measurements. To collect one data record, the MFRSR takes measurements at four different shadowband positions. The first measurement is taken with the shadowband in t… more
Date: February 7, 2011
Creator: Hodges, G. B. & Michalsky, J. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Clean Cities Guide to Alternative Fuel Commercial Lawn Equipment (Brochure)

Description: Guide explains the different types of alternative fuel commercial mowers and lists the makes and models of the ones available on the market. Turf grass is a fixture of the American landscape and the American economy. It is the nation's largest irrigated crop, covering more than 40 million acres. Legions of lawnmowers care for this expanse during the growing season-up to year-round in the warmest climates. The annual economic impact of the U.S. turf grass industry has been estimated at more than… more
Date: October 1, 2011
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

DEPOSITION TANK CORROSION TESTING FOR ENHANCED CHEMICAL CLEANING POST OXALIC ACID DESTRUCTION

Description: An Enhanced Chemical Cleaning (ECC) process is being developed to aid in the high level waste tank closure at the Savannah River Site. The ECC process uses an advanced oxidation process (AOP) to destroy the oxalic acid that is used to remove residual sludge from a waste tank prior to closure. The AOP process treats the dissolved sludge with ozone to decompose the oxalic acid through reactions with hydroxyl radicals. The effluent from this oxalic acid decomposition is to be sent to a Type III wa… more
Date: August 29, 2011
Creator: Mickalonis, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Impact of elevated CO2 and O3 on insect-mediated ecosystem processes in a northern deciduous forest

Description: Rising concentrations of atmospheric CO{sub 2} and O{sub 3} are altering the structure and function of forest ecosystems. Herbivorous insects are the major consumers in temperate deciduous forests, with the capacity to dramatically alter tree growth (via outbreaks), forest community composition and ecosystem dynamics (e.g., nutrient cycling). Until recently, however, experimental quantification of the impacts of CO{sub 2} and O{sub 3} on canopy herbivore communities and rates of defoliation and… more
Date: November 20, 2011
Creator: Lindroth, Richard L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

AIR QUALITY IMPACTS OF LIQUEFIED NATURAL GAS IN THE SOUTH COAST AIR BASIN OF CALIFORNIA

Description: The effects of liquefied natural gas (LNG) on pollutant emission inventories and air quality in the South Coast Air Basin of California were evaluated using recent LNG emission measurements by Lawrence Berkeley National Laboratory and the Southern California Gas Company (SoCalGas), and with a state-of-the-art air quality model. Pollutant emissions can be affected by LNG owing to differences in composition and physical properties, including the Wobbe index, a measure of energy delivery rate. Thi… more
Date: July 1, 2011
Creator: Carerras-Sospedra, Marc; Brouwer, Jack; Dabdub, Donald; Lunden, Melissa & Singer, Brett
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Observations of the Temperature Dependent Response of Ozone to NOx Reductions in an Urban Plume

Description: Observations of NO{sub x} in the Sacramento, CA region show that mixing ratios decreased by 30% between 2001 and 2008. Here we use an observation-based method to quantify net ozone production rates in the outflow from the Sacramento metropolitan region and examine the O{sub 3} decrease resulting from reductions in NO{sub x} emissions. This observational method does not rely on assumptions about detailed chemistry of ozone production, rather it is an independent means to verify and test these as… more
Date: January 25, 2011
Creator: LaFranchi, B W; Goldstein, A H & Cohen, R C
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measuring Atmospheric Ozone and Nitrogen Dioxide Concentration by Differential Optical Absorption Spectroscopy

Description: The main objective was to develop a procedure based on differential optical absorption spectroscopy (DOAS) to measure atmospheric total column of ozone, using the automated instrument developed at the University of North Texas (UNT) by Nebgen in 2006. This project also explored the ability of this instrument to provide measurements of atmospheric total column nitrogen dioxide. The instrument is located on top of UNT’s Environmental Education, Science and Technology Building. It employs a low co… more
Date: December 2011
Creator: Jerez, Carlos J.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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