Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 43 for “"bro"”.
-
Retrieval Advances of BrO/SO2 Molar Ratios from NOVAC
… gas emission at volcanoes. The emissions of BrO and SO2 can be retrieved from the recorded spectra by applying Differential Optical Absorption Spectroscopy(DOAS) and comparing the optical absorption of the volcanic plume to the background. Therefore, the background spectrum must not be …
-
Studies of Stratospheric and Tropospheric Ozone, NO2, and BrO Using UV-Visible Spectroscopy in the Arctic and at Mid-latitudes
… loss compared to that in spring 2011. GBS BrO partial columns were used to investigate Arctic tropospheric ozone depletion during four bromine activation seasons. BrO enhancements show two modes differentiated by air mass history. Contact with the snowpack on sea ice corresponds to …
-
Halogen Oxide Studies in the Boundary Layer by Multi Axis Differential Optical Absorption Spectroscopy and Active Longpath-DOAS
… in the polar boundary layer after polar sunrise (bromine oxide, BrO). Halogen oxides have also been reported from mid-latitude coastal sites (iodine oxide, IO and iodine dioxide, OIO) and from the Dead Sea basin (BrO). Results from the field studies performed in framework of this thesis at Arctic …
-
Observations of Tropospheric and Stratospheric Bromine Monoxide from Satellite : Analysis of Satellite Data derived from GOME for 1996-2001
Column densities of bromine monoxide have been derived from satellite borne Global Ozone Monitoring Experiment measurements for the time period from 1996 to 2001 on a global scale. This data set has been analyzed under various aspects: two methods two achieve a separation of the stratospheric and …
-
Volcanic Gas Studies by Multi Axis Differential Absorption Spectroscopy
… out to study gas emissions from eight volcanoes. Bromine monoxide (BrO), chlorine monoxide (ClO), chlorine dioxide (OClO), formaldehyde (HCHO) and sulphur dioxide (SO2) abundances were measured. A global volcanic BrO flux of 1.2 - 13 Gg/y was determined. The study was focused on the measurements …
-
Spectroscopic measurements of atmospheric trace gases at Neumayer-Station, Antarctica
… of the atmospheric trace gases ozone, NO2, OClO, BrO, IO and O4 were performed using a new UV/Vis spectrograph, developed within the scope of this work. The main intention of DOAS measurements in the Antarctic coastal region was to investigate the chemical composition of the stratosphere, …
-
Electro-reduction of bromate on mercury
<p>"The electrochemical reduction of BrO⁻₃ was studied on a stationary Hg electrode in neutral and basic solutions containing K⁺, Na⁺, and L⁺. Coulombic efficiency studies showed Br⁻ to be the predominant reduction product. The steady state kinetic parameters include Tafel slopes of ca. -0.120 V, …
-
Kinetische Untersuchungen der Halogen-Aktivierung einer simulierten Salzpfanne in einer Smogkammer
… und UV-Absorptionsmessungen die Verläufe der BrO-Radikale. Während Salzpfannen-Experimenten bei einer mittleren RF von 37 % erreichte die Cl-Konzentration ein Maximum von 5 x104 cm-3. Ein rascherer Ozonabbau wurde bei größerer RF und zugleich höherer BrO-Konzentration beobachtet. Bei den …
-
Imaging of bromine oxide and formaldehyde using Fabry-Perot interferometer correlation spectroscopy
… imaging instrument for formaldehyde (HCHO) and bromine oxide (BrO) based on Fabry-Perot interferometer correlation spectroscopy in the UV wavelength range is presented. The technique makes use of the periodic transmission spectrum of a Fabry-Perot-Interferometer and its correlation with the …
-
Investigation of Inorganic Stratospheric Bromine using Balloon-Borne DOAS Measurements and Model Simulations
Inorganic bromine is the second most important halogen effecting stratospheric ozone [WMO2003]. Although the concentration of bromine in the stratosphere is about two orders of magnitude lower than the concentration of chlorine, it currently contributes about 25% to global ozone loss due to its …
-
Investigation of the stratospheric inorganic Bromine budget for 1996 - 2000 : balloon-borne measurements and model comparisons
Inorganic bromine plays an important role in catalytic ozone depletion in the stratosphere at high and mid-latitudes. This study reports and discusses in detail stratospheric DOAS (Differential Optical Absorption Spectroscopy) BrO vertical profile measurements with direct sunlight, that were …
-
Zur Halogenaktivierung im Aerosol und in Salzpfannen
… mit direkter Beobachtung der Halogenoxide BrO, ClO und OClO unter kontrollierten Bedingungen eines Laboratoriums. Dazu wurde die an Forschungsstelle für atmosphärische Chemie vorhandene Teflon-Umweltkammer mit einem Sonnensimulator für troposphärisches Licht und diverser Sensorik …
-
Satellite Observations of Atmospheric Halogen Oxides
… auch absorptionsspektroskopische Messungen von BrO und OClO bei, die beide im ultravioletten Spektralbereich charakteristische Absorptionsstrukturen aufweisen. Diese Messungen wurden entweder vom Boden, Flugzeug oder Ballon aus durchgeführt und konnten damit noch kein umfassendes Bild der …
-
Development and Application of a Versatile Balloon-Borne DOAS Spectrometer for Skylight Radiance and Atmospheric Trace Gas Profile Measurements
… are analyzed for column densities of ozone, NO2, BrO, H2O, and O4 along the line of sight by applying the Differential Optical Absorption Spectroscopy (DOAS) method. Radiative Transfer (RT) calculations are used to (a) simulate the measured quantities and (b) infer vertical profiles of O3, NO2, …
-
Imaging of volcanic trace gases by Fabry-Perot interferometer correlation spectroscopy
… The feasibility of the novel technique for SO2, bromine monoxide (BrO), and formaldehyde (HCHO) is examined in a model study. A prototype of a one-pixel FPI instrument for HCHO is characterised and tested in the laboratory yielding a good agreement between the modelled and measured sensitivity …
-
Studies of Reactive Halogen Species (RHS) in the Marine and mid-Latitudinal Boundary Layer by Active Longpath Differential Optical Absorption Spectroscopy
… Zerstorung bodennahem Ozons durch reaktive Bromverbindungen beobachtet wurde. Weiterhin werden reaktive Iodverbindungen in Zusammenhang mit aktuell beobachteter Partikelbildung in Kustengebieten gebracht. Da Partikel in der Atmosphare die mikrophysikalischen Eigenschaften von Stratocumulus …
-
Antibiotic Resistance: Multi-Drug Profiles and Genetic Determinants.
… determinants than the 2 known forms of the BRO β-lactamase. First, there was overlap in the ranges of inhibition zones. Second, several isolates had antibiotic-specific deviations from typical profiles. These data suggest either more variation in the <em>M. catarrhalis</em> BRO β-lactamase …
-
Ozone-bromide-NOM interactions in water treatment
Ozonation (O$\sb3$) of waters containing bromide (Br$\sp{-}$) results in Br$\sp{-}$ oxidation to first hypobromite ion (OBr$\sp{-}$) and its conjugate acid (HOBr), and eventually bromate (BrO$\sb{3\sp{-}}$), a suspected carcinogen. Natural organic matter (NOM) reads with HOBr/OBr$\sp{-}$ to form …
-
The relative contribution of free radicals to the oxidation chain of Dimethylsulphide in the marine boundary layer
… bei Weitem übertreffen. Während so genannter �Bromexplosionen� kann Bromoxid (BrO) auf lokaler Ebene eine dominerende Senke für DMS darstellen. Der Abbau von DMS steht am Anfang eines komplexen Oxidationsmechanismus dessen Ablauf wesentlich durch die Mischungsverhältnisse von Sticktoffoxiden …
-
Tides, Winds, and Reactive Halogens A Study of Multiphase Chemistry in the Marine Boundary Layer
… (inorganic compounds containing chlorine, bromine, and/or iodine)have the ability to catalytically destroy ozone (O3) as well as react with NOx (= NO + NO2) , influencing concentrations and ratios of important tropospheric pollutants. They can also react with and change the ratio of OH and …
Page 1 of 3