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Degradation of Naphthenic Acids in Athabasca Oil Sands Process-Affected Water Using OzoneHongjing , Fu Unknown Date
No description available.
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Recovery of refrigerant vapor leakage using high pressure psychrometricsWright, Jeffery Raymond 08 1900 (has links)
No description available.
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The Chemical Sensitivity of Stratospheric Ozone to N₂O and CH₄ through the 21st centuryRevell, Laura Eleanor January 2012 (has links)
Through the 21st century, global-mean stratospheric ozone abundances are projected to increase due to decreasing chlorine and bromine concentrations (as a consequence of the Montreal Protocol for Substances that Deplete the Ozone Layer), and continued CO₂-induced cooling of the stratosphere. Along with CO₂, anthropogenic emissions of the greenhouse gases N₂O and CH₄ are projected to increase, thus increasing their atmospheric concentrations. Consequently, reactive nitrogen species produced from N₂O and reactive hydrogen species produced from CH₄ are expected to play an increasingly important role in determining stratospheric ozone concentrations. Chemistry-climate model simulations were performed using the NIWA-SOCOL (National Institute of Water and Atmospheric Research - SOlar Climate Ozone Links) model, which tracks the contributions to ozone loss from a prescribed set of catalytic cycles, including the ozone-depleting nitrogen and hydrogen cycles, over latitude, longitude, pressure and time. The results provide a comprehensive picture of how stratospheric ozone may evolve through the 21st century under a range of greenhouse gas emissions scenarios, and quantitatively extend concepts that had previously been understood only qualitatively.
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Spin-coated antimony- and nickel-doped tin dioxide electrodes foranodic ozone evolutionSjölander, Joel January 2015 (has links)
This work have served as a preliminary work for a more extensiveresearch on antimony- and nickel-doped tin dioxide electrodes used forozone generation in electrolytic reactions. The target has been to test themanufacturing process of Sb/Ni-doped SnO2 with spin-coating techniqueand succeed to make electrodes for anodic ozone evolution and tocharacterize them. Electrode manufacturing was made using sol-gelfrom chloride salts of tin, antimony and nickel, which were applied to atitanium substrate through spin-coating. The substrates were spun todifferent thickness followed by drying and baking of the substrate. A setof electrodes with three layers were made just with spin-coating, additionallya set of electrodes with twenty layers were made with bothspin-coating and dip-coating. To characterize physical properties of theelectrodes, x-ray diffraction, scanning electron microscopy and transmissionelectron microscopy were conducted. Electrochemical measurementswere made in open beakers with a platinum cathode andsulphuric acid electrolyte using a galvanostatic measurement with afixed current. To measure the ozone evolution the optical absorbancedifference from the electrolyte compared to a clean electrolyte wasmeasured, this however only measures the amount of aqueous ozonepresent. Assembling of SnO2 electrodes for ozone evolution was successful.For the three-layered electrodes the absorbance readings wereinconclusive but with the twenty-layered electrodes there was a smell ofozone present within the electrolyte and absorbance reading of the dipcoatedelectrode presented a clear peak for ozone.
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Effect Of Controlled Atmosphere Storage, Modified Atmosphere Packaging And Gaseous Ozone Treatment On The Survival Characteristics Of Salmonella Enteritidis At Cherry TomatoesDas, Elif 01 July 2004 (has links) (PDF)
iv
In recent years, outbreaks of infections associated with raw and
minimally processed fruits and vegetables have been reported. Possible
sources for contamination are irrigation water, manure, wash water, handling
by workers and contact with contaminated surfaces. Pathogens can occur on
raw and minimally processed produce at populations ranging from 103 to 109
CFU/g and able to survive and sometimes grow under various storage
conditions. The objective of this study was to analyse the growth/survival of
Salmonella Enteritidis at spot-inoculated or stem-injected cherry tomatoes
during passive modified atmosphere packaging (MAP), controlled
atmosphere (CA) and air storage at 7 and 22° / C. Low density polyethylene
(LDPE) with a package size of 10x10 cm2 for 25± / 2 g tomatoes was used for
MAP storage in which the gas composition equilibrated to 6% O2/ 4% CO2
and a carbon dioxide incubator was used for CA storage in which the CO2
level was monitored and maintained as 5% through the term of storage at 7
and 22° / C. During the research, the effect of ozone treatment (5-30 mg/L
ozone gas for 0-20 min) was also considered for surface sanitation. The
results demonstrate that S.Enteritidis can survive and/or grow during the
storage of tomatoes depending on the location site of the pathogen on fruit,
suspension cell density and storage temperature. During MAP, CA and air
storage, S.Enteritidis with initial population of 7.0 log10 CFU/tomato survived
on tomato surfaces with an approximate decrease of 4.0-5.0 log10
CFU/tomato in population within the storage period / however, in the case of
initial population of 3.0 log10 CFU/tomato, cells died completely on day 4
during MAP storage and on day 6 during CA and air storage. The death rate
of S.Enteritidis on the surfaces of tomatoes that were stored in MAP was
faster than that of stored in air. Storage temperature was effective on the
survival of S.Enteritidis for the samples stored at ambient atmosphere / cells
died completely on day 6 at 7° / C and on day 8 at 22° / C. Stem scars provided
protective environments for Salmonella / an approximate increase of 1.0 log10
CFU/tomato in stem-scar population was observed during MAP, CA and air
storage at 22° / C within the period of 20 days. Cells survived with no
significant change in number at 7° / C. The development of the microbial
association in tomatoes was dominated by lactic acid bacteria (LAB). The pH
values of the tomatoes changed approximately from 4.0 to 3.0 during the
storage period. LAB grew well under all atmospheric conditions with or
without the presence of S.Enteritidis. Gaseous ozone treatment has
bactericidal effect on S.Enteritidis, inoculated on the surface of the tomatoes.
5 mg/L ozone gas treatment was not effective. 30 mg/L ozone gas treatment
affected surface color.
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Degradation of Naphthenic Acids in Athabasca Oil Sands Process-Affected Water Using OzoneHongjing , Fu 06 1900 (has links)
In order to determine the degradation of Naphthenic Acids (NAs) in oil sands process-affected water (OSPW), a series of semi-batch ozonation experiments have been conducted resulting in a maximum reduction of NAs greater than 99%. Compared to the high NAs removal, the reduction of both COD and DOC was much lower under the same conditions. Following ozone treatments of approx. 80 mg/L, the cBOD5 and cBOD5/COD tripled as compared to original OSPW measurements, suggesting ozone-treated OSPW has a higher biodegradability. The ozone treatments also detoxified the OSPW; with an ozone treatment of approx. 100 mg/L, the treated OSPW showed no toxicity using the Mircotox® bioassay. Additionally, the coke-treated OSPW, treated using a coke/water slurry process, was found to be non-toxic with an ozone treatment of approx. 20 mg/L. The results obtained during this study shows the great potential ozonation may offer as a possible water treatment application for oil sands water management. / Environmental Engineering
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Spatial and temporal distribution of ozone over Houston during the 2006 Texas air quality studyTytell, Jonathan E January 2007 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 94-97). / ix, 97 leaves, bound ill., maps 29 cm
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Applications and evaluation of receptor modeling methods for source contribution of volatile organic compoundsSnorradottir, Thorunn. January 2006 (has links)
Thesis (Ph. D.)--University of Nevada, Reno, 2006. / "August, 2006." Includes bibliographical references (leaves xx-xx). Online version available on the World Wide Web.
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The coupling of dynamics and chemistry in the Antarctic stratosphere : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Physics in the University of Canterbury /Huck, Petra E. January 2007 (has links)
Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. [127]-142). Also available via the World Wide Web.
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Evidence, policy and practice in environmental health : an international case study of sun safety /Garvin, Theresa Dawn. January 1999 (has links)
Thesis (Ph.D.) -- McMaster University, 1999. / Includes bibliographical references (leaves 191-210). Also available via World Wide Web.
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