Search results for "Ozone"
showing 10 items of 300 documents
Ozone absorption in aqueous phenol solutions
1977
Abstract The rate of ozone absorption in aqueous solutions of phenol was measured in a wetted-wall laboratory absorber. The liquid and gas flow rates were fixed as well as the pH and temperature. The phenol concentration was varied in the range 2–300 ppm and the ozone partial pressure over an eight fold range. The gas phase resistance to mass transfer was determined by absorbing SO2 from an SO2N2 mixture in KOH aqueous solutions. The results have been interpreted by means of a simple kinetic assumption.
Redistribution of total reactive nitrogen in the lowermost Arctic stratosphere during the cold winter 2015/2016
2021
During winter 2015/2016 the Arctic stratosphere was characterized by extraordinarily low temperatures in connection with the occurrence of extensive polar stratospheric clouds. From mid of December 2015 until mid of March 2016 the German research aircraft HALO (High Altitude and Long–Range Research Aircraft) was deployed to probe the lowermost stratosphere in the Arctic region within the POLSTRACC (Polar Stratosphere in a Changing Climate) mission. More than twenty flights have been conducted out of Kiruna/Sweden and Oberpfaffenhofen/Germany, covering the whole winter period. Besides total reactive nitrogen (NOy), observations of nitrous oxide, nitric acid, ozone and water were used f…
ChemInform Abstract: Elemental Bromine Production by TiO2Photocatalysis and/or Ozonation.
2016
Significant production of elemental bromine (Br2 ) was observed for the first time when treating bromide containing solutions at acidic pH, with TiO2 photocatalyst, ozone, or a combination thereof. Br2 selectivities up to approximately 85 % were obtained and the corresponding bromine mass balance values satisfied. The process is general and may be applied at a laboratory scale for green bromination reactions, or industrially as a cheap, safe, and environmentally sustainable alternative to the currently applied bromine production methods.
Comparison of Inorganic Chlorine in the Southern Hemispheric lowermost stratosphere during Late Winter 2019
2021
Inorganic chlorine (Cly) is the sum of the degradation products of long-lived chlorinated source gases. These include the reservoir species (HCl and ClONO2) and active chlorine species (i.e. ClOx). The active chlorine species drive catalytic cycles that deplete ozone in the polar winter stratosphere. This work presents calculations of inorganic chlorine (Cly) derived from chlorinated source gas measurements on board the High Altitude and Long Range Research Aircraft (HALO) during the Southern hemisphere Transport, Dynamic and Chemistry (SouthTRAC) campaign in late winter and early spring 2019. Results are compared to Cly of the Northern Hemisphere derived from measurements of the POLSTRACC-…
Taurine and the Lung
2003
Taurine (TAU) is the most abundant free amino acid in many tissues and in particular in proinflammatory cells like polymorphonuclear leukocytes and tissues exposed to elevated levels of oxidants1. Furthermore, orally administered TAU has been reported to reduce lung oxidant damage from exposure to ozone, nitrogen dioxide, paraquat, amiodarone and bleomycin in animal models2–5.
Application of Machine Learning Techniques in the Study of the Relevance of Environmental Factors in Prediction of Tropospheric Ozone
2010
This work presents a new approach for one of the main problems in the analysis of atmospheric phenomena, the prediction of atmospheric concentrations of different elements. The proposed methodology is more efficient than other classical approaches and is used in this work to predict tropospheric ozone concentration. The relevance of this problem stems from the fact that excessive ozone concentrations may cause several problems related to public health. Previous research by the authors of this work has shown that the classical approach to this problem (linear models) does not achieve satisfactory results in tropospheric ozone concentration prediction. The authors’ approach is based on Machin…
Emersion generalisee intra-maastrichtienne de la plate-forme de Gavrovo-Tripolitza (Grece); effets sur les populations de foraminiferes Rhapydioninin…
2001
Abstract The reliability of biostratigraphic correlations in neritic carbonate platforms is often questioned because the benthic fauna on which biozonation is based are particularly sensitive to environmental change. It is crucial to know whether a population change corresponds strictly to a facies change. Conversely, there arise the questions of determining how populations are renewed over time and how new species appear even if facies associations remain unchanged. This is the case with the Gavrovo-Tripolitza zone of Greece, an isolated shallow carbonate platform surrounded by two oceanic domains (Pindos-Olonos Zone and Ionian Zone). The absence or scarcity of faunas generally used in Upp…
Clinical Study of Patients with Heart Failure under treatment with Ozone Therapy.
2018
Heart failure (HF) is framed in one of the types of cardiovascular diseases; it consists of an acute and chronic form. The disease can evolve slowly from asymptomatic left ventricular dysfunction, to a state of severe disability, presenting a wide prevalence in the population around 10% in people over 70 years old. More than three-quarters of the deaths from this pathology normally occur in low or middle-income countries. Angola is not exempt from this health problem be observed in a relatively young people, bringing disability and death at an early stage of life. Scientific advances and innovative treatments for the control and prevention of the disease continue to be insufficient.
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Identification of a Functional Homolog of the Yeast Copper Homeostasis Gene ATX1 from Arabidopsis1
1998
Abstract A cDNA clone encoding a homolog of the yeast (Saccharomyces cerevisiae) gene Anti-oxidant 1(ATX1) has been identified from Arabidopsis. This gene, referred to as CopperCHaperone(CCH), encodes a protein that is 36% identical to the amino acid sequence of ATX1 and has a 48-amino acid extension at the C-terminal end, which is absent from ATX1 homologs identified in animals. ATX1-deficient yeast (atx1) displayed a loss of high-affinity iron uptake. Expression of CCH in the atx1 strain restored high-affinity iron uptake, demonstrating thatCCH is a functional homolog of ATX1. When overexpressed in yeast lacking the superoxide dismutase geneSOD1, both ATX1 and CCHprotected the cell from t…