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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Experimentelle Studien zur räumlichen Struktur und Dynamik des Sommersmogs über dem Schweizer Mittelland /

Künzle, Thomas. Neu, Urs. January 1994 (has links)
Zugl.: Diss. phil.-nat. Univ. Bern, 1994. / Ed. commerciale de la thèse de l'Univ. de Bern. Literaturverz.
32

Studies of the stratospheric nitrogen and iodine chemistry by balloon-borne DOAS measurements and model calculations

Bösch, Hartmut. Unknown Date (has links) (PDF)
University, Diss., 2002--Heidelberg.
33

Luftrening för industriella processer - Dimensionering av ett luftreningssystem i pilotskala / Gas Treatment for Industrial Processes - Design of a Pilot Scale Gas Treatment System

Chroona, Gustaf, Duman, Isa January 2013 (has links)
Industriella processer inom livsmedelsindustrin ger ofta upphov till förorenade luftflöden. Föroreningarna förekommer både i partikulär- och gasform. En anledning till att vidta åtgär-der för att kontrollera utsläppet kan både vara förknippat med krav från myndigheter eller med hänsyn till krav från omgivningen. Det övergripande målet med examensarbetet var att konstruera ett lättportabelt luftreningssy-stem i pilotskala som skulle användas till förtester på förorenad luft från industriella proces-ser. Driftsdata från sådana körningar ger värdefull information om hur ett storskaligt renings-system kan konstrueras för att uppnå önskad reningsgrad. Arbetet var ett uppdrag från företaget Ozone Tech Systems. Företaget är specialiserat på re-ning med ozon, men tillhandahåller även andra tekniska lösningar som tas fram utifrån kun-dernas behov. Arbetet har utförts i nära relation med leverantörer samt personalen på företa-get. Pilotsystemet konstruerades med utgångspunkt från den typ av förorenad luft som uppkom-mer vid varmrökning av fisk med träspån av al, men ska även kunna användas till andra pro-cesser som ger upphov till liknande typ av förorenad luft. Genom utnyttjande av emissions-faktorer men även tillgänglig fakta från litteraturen samt uppmätta värden, gick det att upp-skatta föroreningsinnehållet och tillståndet för luften. Reningskravet som designen utgick ifrån var både EUs krav för TOC <50 mg/m3 (n) samt att reducera oönskad lukt. Odören vi-sade sig framförallt uppkomma från flyktiga organiska föreningar (VOC). Pilotsystemet var förutbestämt att bestå av en primär partikelavskiljare, oxidation med ozon, sekundär partikelavskiljning med ett HEPA 13 filtersteg samt slutligen ett adsorptionssteg med aktivt kol. I designprocessen beslutates sedan att använda en venturiskrubber som en primär partikelavskiljare samt att placera förfilter innan HEPA 13 filtret. Arbetet har resulterat i en teoretiskt framtagen design för luftreningssystemet. Apparatdelarna är isärtagbara för enkel transport samt möjlighet till anpassad appartturkombination. Inköpet av apparatdelarna har inte varit en del av examensarbetet men samordning av inköpet har genomförts till den nivån att inköpet direkt skulle kunna genomföras vid projektets slut. För att systemet ska fungera krävs att en fläkt för att motverka tryckfallet samt rörkopplingar mellan apparatdelarna dimensioneras och inhandlas, vilket inte ingick i projektet. / Industrial processes in the food industry very often produce airstreams of contaminated air. The impurities can be both particulates and gaseous compounds. Controlling these emissions is of a great concern both regarding governmental and social requirements. The overall aim with the thesis was to construct an easily portable, pilot scale air purification system. The main purpose with the pilot scale system was to enable testing of contaminated air generated from industries. The results from the industry tests with the pilot scale system would reveal valuable information that could be used later for the design of a large scale cleaning system. The work was assigned by Ozone Tech Systems. The company is specialized in ozone treat-ments intended for industrial and domestic uses. The work done within the thesis project was performed in close relations with equipment suppliers and Ozone Tech System personnel. The design of the pilot scale air purification system was based on contaminated air, generated from fish smokehouses. The smoke that is involved in the hot smoking process is derived in conjunction with alder chips smoldering. Although the pilot scale system was designed for purifying air generated from fish smokehouses, it should also suit other processes that gener-ate similar air emissions. Emission factors, literature data and measured values played an im-portant role for estimating the air composition in the air generated from the specific process. The treatment objective was determined by European regulations as well as a desired reduc-tion of unwanted odors. The odor was found to mainly be caused by volatile organic com-pounds (VOC). The pilot system was predefined to consist of a primary step of particle separation, oxidation with ozone, particle separation consisting of a HEPA 13 filtration stage and at last adsorption with activated carbon. During the design process it was decided to use a venturi scrubber as the primary particle separator and to add a pre-filter stage before the HEPA 13 filter. The work has resulted in a theoretical design of the air purification system. The units are de-tachable which provides a simple transportation as well as the possibility to use an adaptable combination of the units. The purchase of equipment was not a part of the thesis, but the coordination of the purchase has been completed ensuring that the purchase could be done after the end of the project. In order for the system to work, a fan needs to be installed and pipe connections between the units have to be designed and purchased, but this was not a part in the project.
34

Intimate Spaces in Francois Ozons Swimming Pool

Tasevska, Tamara 18 August 2014 (has links)
No description available.
35

Ozonentwicklung im polnisch-sächsischen Grenzraum: Ozonentwicklung im polnisch-sächsischen Grenzraum im Rahmen des Projektes KLAPS

Heidenreich, Majana, Riedel, Kathrin, Fischer, Stefanie, Bernhofer, Christian 06 May 2015 (has links)
Ein Teilziel des Projektes KLAPS ist eine auf die Projektregion ausgerichtete Analyse der Ozonbelastung in Abhängigkeit klimatischer Einflussfaktoren. Im vorliegenden Bericht werden die zeitlichen Verläufe der Vorläufersubstanzen und der Einfluss meteorologischer Bedingungen auf die Ozonkonzentration im 21. Jahrhundert untersucht. Die Ergebnisse verweisen auf einen möglichen Anstieg der Ozonkonzentration in den Sommermonaten der nächsten Jahrzehnte allein durch die Auswirkungen des Klimawandels. Entscheidend für die zukünftige Höhe der Ozonkonzentration ist allerdings die Entwicklung der Emissionen im Projektgebiet.
36

Efekti primene ozona, ozon/vodonik-peroksida i hipohlorita na sadržaj prirodnih organskih materija i oksidacionih nusproizvoda u vodi, nakon procesa koagulacije, flokulacije i adsorpcije / Effect of ozone, ozone/hydrogen peroxide and hypoclorite on natural organic matter and oxidation by-products content in water after coagulation, floculation and adsorption procesess

Tubić Aleksandra 06 September 2010 (has links)
<p>Cilj ovog rada je bio da se ispita uticaj ozona i ozon/vodonik-peroksida na efikasnost uklanjanja POM i prekursora oksidacionih nusproizvoda, procesima koagulacije, flokulacije i adsorpcije. Posebna pažnja posvećena je ispitivanju uticaja navedenih procesa na sadržaj prekursora oksidacionih nusproizvoda hlora (trihalometana i halosirćetnih kiselina), kao i na uticaj hipohlorita na formiranje ovih jedinjenja u tretiranoj vodi. Analiza hemijskih karakteristika sirove podzemne vode kori&scaron;ćene u ispitivanjima pokazuje da sadrži visok nivo POM pretežno hidrofobnog karaktera (PB = 37,7&plusmn;0,60 mg KMnO4/l; DOC = 9,27&plusmn;0,92 mg C/l; UV254 = 0,497&plusmn; 0,015 cm-1; SUVA = 5,36&plusmn;0,49 1 mg-1 m-1; PFTHM = 555&plusmn;128 &micro;g/l; PFHAA = 245&plusmn;54,9 &micro;g/l), kao i visoku koncentraciju arsena (51,7&plusmn;16,4 &micro;g/l).<br />Poređenjem uticaja dve ispitivane vrste koagulanata (FeCl3 i FeCl3/PACl) utvrđeno je da imaju različite mehanizme uklanjanja POM i prekursora oksidacionih nusproizvoda. FeCl3/PACl omogućava smanjenje sadržaja POM izraženih preko vrednosti DOC, PB, UV254 apsorbancije i SUVA za 54%, 71%, 88% i 74%, u odnosu na sirovu vodu respektivno, dok se koagulacijom sa FeCl3 postiže smanjenje DOC, PB, UV254 apsorbancije i SUVA za 51%, 48%, 61% i 21%, respektivno. U vodi nakon koagulacije sa FeCl3 zaostaju POM hidrofobnog karaktera (SUVA = 5,12 l m-1 mg-1), dok se POM u koagulisanoj vodi sa FeCl3/PACl, mogu okarakterisati kao hidrofilne (SUVA = 1,70 l m-1 mg-1). Koagulacija sa FeCl3 i FeCl3/PACl omogućila je smanjenje sadržaja arsena u vodi za preko 95%, pri čemu su koncentracije As u koagulisanoj vodi bile niže od 10 &micro;g/l. Ozon i O3/H2O2 proces pokazuju sličnu efikasnost u smanjenju sadržaja POM i prekursora oksidacionih nusproizvoda. Poređenjem kombinovanih tretmana koji obuhvataju oksidacioni predtretman i koagulaciju, utvrđeno je da efikasnost koagulacije sa FeCl3 i FeCl3/PACl u smanjenju vrednosti DOC, PB, UV254, SUVA, PFTHM i aldehida, uglavnom zavisi od mehanizma delovanja samih koagulanata, dok ozon i O3/H2O2 proces doprinose smanjenju vrednosti ovih parametara kroz oksidaciju i izdvajanje lako isparljivih komponenti iz vode stripingom gasa. Sa aspekta promene sadržaja prekursora HAA, ozon i O3/H2O2 proces omogućavaju povećanje efikasnosti procesa koagulacije sa FeCl3 i FeCl3/PACl, u odnosu na koagulaciju bez oksidacionog predtretmana.<br />Kada se uzmu u obzir vrednosti svih navedenih parametara, kao i primenjenje doze oksidacionih sredstava i koagulanata, najbolji rezultati u uklanjanju POM i prekursora oksidacionih nusproizvoda (smanjenje vrednosti DOC za 55%, UV254 i SUVA za vi&scaron;e od 90%, u odnosu na sirovu vodu; PB = 7,70 mg KMnO4/l;&nbsp; PFTHM =158-188 &micro;g/l; PFHAA = 33,0-53,8 &micro;g/l i sadržaj aldehida 16,7-17,9 &micro;g/l) postižu se primenom tretmana koji obuhvataju oksidacioni predtretman ozonom (3,0 g O3/m3), odnosno O3/H2O2&nbsp; (3,3 g O3/m3; H2O2:O3 =1:1), koagulaciju (30 g FeCl3/m3 / 30 g Al/m3) uz recirkulaciju flokulacionog mulja i adsorpciju na zeolitu, flokulaciju, sedimentaciju i filtraciju na pe&scaron;čano/antracitnom filtru.<br />Za zavr&scaron;nu obradu vode GAU filtracijom pre procesa dezinfekcije, na osnovu svih ispitivanih parametara, kao najefikasniji u uklanjanju POM i prekursora oksidacionih nusproizvoda (THM, HAA i aldehida) pokazao se GAU Norit Row 0,8 Supra.<br />Hlorisanjem u simuliranim uslovima dezinfekcije, utvrđeno je da voda dobijena nakon GAU filtracije u ispitivanim tretmanima, ima zadovoljavajući kvalitet sa aspekta sadržaja THM i HAA (sadržaj THM je 69,7-77,4 &micro;g/l; koncentracija DCAA je &lt; MDL) čije su maksimalno dozvoljene koncentracije regulisane u vodi za piće (100 &micro;g/l za THM i 50 &micro;g/l za DCAA).<br />Statističkom obradom podataka iz laboratorijskih i pilot ispitivanja utvrđene su empirijske zavisnosti koje se mogu primenjivati za predviđanje koncentracije THM i HAA u tretiranoj vodi nakon tretmana ispitivanih na pilot postrojenju. Da bi se mogle primeniti za druge vrste vode i drugačije dizajnirane tetmane, neophodno je izvr&scaron;iti validaciju primenom nezavisnog seta podataka.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br />Svi rezultati dobijeni u toku istraživanja ukazuju na neophodnost primene oksidacionih sredstava u tretmanu ispitivane podzemne vode. Zbog različitog mehanizma delovanja, neophodno je izvr&scaron;iti odabir odgovarajuće vrste i doze oksidacionog sredstva, kao i koagulanta u tretmanu vode za piće, uzimajući u obzir karakteristika sirove vode i efikasnost koja se želi postići. Primena optimalnih doza ozona i O3/H2O2 omogućava povećanje efikasnosti uklanjanja POM i prekursora oksidacionih nusporizvoda, procesima koagulacije, flokulacije i adsorpcije. Odabirom odgovarajućih uslova tretmana postiže se da i nakon hlorisanja u postupku dezinfekcije, voda zadovoljava kriterijume kvaliteta vode za piće, sa aspekta sadržaja trihalometana i halosirćetnih kiselina.</p> / <p>The aim of this work was to investigate influence of ozone and ozone/hydrogen peroxide on efficiency of coagulation, flocculation and adsorption on natural organic matter and oxidation by-products removal. Special attention was dedicated to investigation of these processes on chlorine oxidation by-products (trihalomethanes and haloacetic acids) as well as on hypochlorite influence on formation of these compounds in treated water. The analysis of chemical characteristics of raw ground water used in this investigation show that it contains high amount of NOM, mainly of hydrophobic nature (PB = 37,7&plusmn;0,60 mg KMnO4/l; DOC = 9,27&plusmn;0,92 mg C/l; UV254 = 0,497&plusmn; 0,015 cm-1; SUVA = 5,36&plusmn;0,49 1 mg-1 m-1; PFTHM = 555&plusmn;128 &mu;g/l; PFHAA = 245&plusmn;54,9 &mu;g/l) as well as high arsenic concentration (51,7&plusmn;16,4 &mu;g/l).<br />Comparing the influences of two investigated coagulants (FeCl3 and FeCl3/PACl) it was observed that they have different mechanisms of NOM and oxidation by-products precursors&rsquo; removal. FeCl3/PACl enables reduction of DOC, PB, UV254 absorbance and SUVA value for 54%, 71%, 88% i 74%, respectively, relative to raw water. Coagulation with FeCl3 provides reduction of DOC, PB, UV254 absorbance and SUVA for 51%, 48%, 61% i 21%, respectively. In water coagulated with FeCl3 remains NOM of hydrophobic nature (SUVA = 5,12 l m-1 mg-1) while NOM in coagulated water with FeCl3/PACl can be characterized as hydrophilic (SUVA = 1,70 l m-1 mg-1). Coagulation with FeCl3 and FeCl3/PACl enables arsenic content reduction for over 95% relative to raw water, with As concentrations in coagulated water below of 10 &mu;g/l. Ozone and O3/H2O2 process demonstrates similar efficiency in NOM and oxidation by-products precursors content reduction. Comparing combined treatment which includes oxidation pretreatment and&nbsp;<span style="font-size: 12px;">coagulation, it was observed that efficiency of coagulation in DOC, PB, UV254, SUVA, PFTHM and aldehydes reduction mainly depends on coagulants activity mechanisms, while ozone and O3/H2O2 process contributes to reduction of these parameters through oxidation and removal of volatile compounds from water by gas stripping. Ozone and O3/H2O2 process enables increase of coagulation efficiency for HAA precursor&rsquo;s removal, comparing to coagulation without oxidation pretreatment.</span></p><p>Taking into account all measured parameters as well as applied doses of oxidation reagents and coagulants, it can be concluded that the best results in NOM and oxidation by-products precursors content reduction (decrease of DOC for 55%, UV254 i SUVA for more then 90%, related to raw water; PB = 7,70 mg KMnO4/l; PFTHM =158-188 &mu;g/l; PFHAA = 33,0-53,8 &mu;g/l and content of aldehydes 16,7-17,9 &mu;g/l) can be obtained by treatments which include oxidation pretreatment with ozone (3,0 g O3/m3), as well as with O3/H2O2 (3,3 g O3/m3; H2O2:O3 =1:1), coagulation (30 g FeCl3/m3 / 30 g Al/m3), with flocculation sludge recirculation and zeolit adsorption, flocculation, sedimentation and filtration on sand/anthracite filter.<br />For the final water treatment with GAC filtration before disinfection process, based on all parameters, GAC Norit Row 0,8 Supra was the most efficient in NOM and oxidation by-products precursors reduction (THM, HAA and aldehydes).<br />After chlorination in simulated disinfection conditions, it was determined that water after GAC filtration in investigated treatments has satisfactory quality in terms of regulated THM and HAA (content of THM is 69,7-77,4 &mu;g/l; concentration of DCAA is &lt; MDL) which maximal allowable level for drinking water is established (100 &mu;g/l for THM and 50 &mu;g/l for DCAA).<br />By statistical analysis of data obtained in laboratory and pilot scale experiments it was determined empirical relations for THM and HAA concentration predictions in treated water.<br />All obtained results in this research indicate that oxidation reagents need to be applied in treatment of investigated ground water. Because of different action mechanism, it is necessary to select the adequate type and dose of oxidation reagent and coagulant in water treatment, taking into account characteristics of raw water and efficiency that needs to be achieved. Application of optimal doses of ozone and O3/H2O2 enables increase of coagulation, flocculation and adsorption efficiency in NOM and oxidation by-products precursors&rsquo; removal. Selection of adequate treatment conditions provides that after chlorination in disinfection process water satisfies drinking water quality criteria, in terms of trihalomethanes and haloacetic acids.</p>
37

Processo de ozon?lise aplicado ao aproveitamento tecnol?gico de res?suos de coco verde / Ozonolysis process applied to the technological use of green coconut waste

Gurgel, Monique de Moura 29 April 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-21T17:26:15Z No. of bitstreams: 1 2016 - Monique de Moura Gurgel.pdf: 5504454 bytes, checksum: 56c93476cae66a9ba7cfc9cad8b26016 (MD5) / Made available in DSpace on 2017-03-21T17:26:15Z (GMT). No. of bitstreams: 1 2016 - Monique de Moura Gurgel.pdf: 5504454 bytes, checksum: 56c93476cae66a9ba7cfc9cad8b26016 (MD5) Previous issue date: 2016-04-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The chemical analysis and structural analyzes of tropical biomass products has become a potential interest for the production of biofuels. Residues from coconut is promising because it doesn`t compete with the food industry and it can be transformed into a higher product added value due the lignocellulosic origin. Green coconuts had been separated between fiber and parenchyma following by anatomical characterization which it could better be understood and visualized the effect of pretreatment delignification; ozonolysis, with the chemical and compositional changes in the cell wall. To access the carbohydrates, lignin must be removed, thus it had been explored the changes induced by ozone under pH conditions; with addition of acetic acid and sodium hydroxide, and treatment time in milli-Q water. The ozonolysis was carried out at pH 3, 5 and 8 for 2; 4 and 6 hours at 25 ? C. Analyses were performed before and after the ozonolysis reaction to investigate the change of polysaccharides and lignin with the following techniques: SEM, Py-GC/MS, HPLC, FT-IR and TGA. With Scanning electron microscope and infrared spectroscopy, it was possible to observe the degradation of structural components of the fibers, in the form of "spring", from 4 hours of oxidation and changes in the intensities of the bands. According to the Py-GC/MS results, compounds resulting from lignin had been identified and stablished S/G ratio as 0,73. With a lignin Klason content of 26.28% from green coconut fiber and 25.45% from parenchyma. The best conditions of ozone treatment were determined to be the fiber with no addition of reagents for 4 hours under oxidation as determined by the increase of glucose content in the hydrolysate to 45.96 % after acid hydrolysis of ozone treated fibers. / An?lises qu?micas e estruturais dos produtos de biomassa tropical tem se tornado um potencial interesse para produ??o de novos produtos que agreguem valores sustent?veis, dentre eles, os biocombust?veis. Res?duos de coco se tornam promissores pois n?o competem com a ind?stria aliment?cia e podem ser transformados em um produto de maior valor agregado visto serem de origem lignocelul?sica. Nesse contexto, os cocos verdes foram separados entre fibra e par?nquima e por conseguinte, caracterizados a n?vel anat?mico para que melhor pudesse ser compreendido a rela??o do tratamento utilizado para deslignifica??o; no caso, a ozon?lise, assim como as altera??es qu?micas e composicionais da parede celular. Para acessar os carboidratos, a lignina precisa ser removida, portanto foi explorado as mudan?as induzidas pelo oz?nio sob condi??es de pH; atrav?s adi??o de ?cido ac?tico e hidr?xido de s?dio, e tempo. O tratamento com oz?nio em solu??o de ?gua biodeionizada foi conduzido em pH 3, 5 e 8 por 2, 4 e 6 horas a temperatura de 25?C. As an?lises foram realizadas com amostras anteriores e posteriores ? rea??o de ozon?lise, investigando as altera??es dos polissacar?deos e da lignina com as seguintes t?cnicas: MEV, Pi-GC/MS, CLAE, FT-IR e TGA. De acordo com a Microscospia eletr?nica de varredura e Espectroscopia de infravermelho, foi poss?vel observar a degrada??o dos componentes estruturais das fibras, em forma de ?mola?, a partir de 4 horas de oxida??o e altera??es nas intensidades das bandas respecivamente. De acordo com a Pi-GC/MS, os derivados da lignina foram identificados e estabelecido uma rela??o S/G de 0,73 para fibra. O teor de lignina de Klason foi de 26,28% para a fibra e 25,45% para o par?nquima. Em visto disso, chegou-se a conclus?o que a melhor condi??o de tratamento com oz?nio foi obtido com as fibras sem adi??o de reagente sob 4 horas de exposi??o ao agente oxidante, determinado pelo aumento do teor de glicose a 45,96%.
38

Bestimmung von Ozonabbauraten über der Arktis und Antarktis mittels Ozonsonden- und Satellitendaten / Determination of ozone loss rates over the Arctic and Antarctic using ozone sonde and satellite data

Streibel, Martin Albert Gerhard January 2005 (has links)
Diese Arbeit beschäftigt sich mit der chemischen Ozonzerstörung im arktischen und antarktischen stratosphärischen Polarwirbel. Diese wird durch Abbauprodukte von anthropogen emittierten Fluorchlorkohlenwasserstoffen und Halonen, Chlor- und Bromradikale, verursacht. Studien in denen der gemessene und modellierte Ozonabbau verglichen wird zeigen, dass die Prozeße bekannt sind, der quantitative Verlauf allerdings nicht vollständig verstanden ist. <br><br> Die Prozesse, die zur Ozonzerstörung führen sind in beiden Polarwirbeln ähnlich. Allerdings fällt als Konsequenz unterschiedlicher meteorologischer Bedingungen der chemische Ozonabbau im arktischen Polarwirbel weniger drastisch aus als über der Antarktis. Der arktische Polarwirbel ist im Mittel stärker dynamisch gestört als der antarktische und weist eine stärkere Jahr-zu-Jahr Variabilität auf. Das erschwert die Messung des chemischen Ozonabbaus. Zur Trennung des chemischen Ozonabbaus von der dynamischen Umverteilung des Ozons im arktischen Polarwirbel wurde die Matchmethode entwickelt. Bei dieser Methode werden Luftpakete innerhalb des Polarwirbels mehrfach beprobt, um den chemischen Anteil der Ozonänderung zu quantifizieren. Zur Identifizierung von doppelt beprobten Luftpaketen werden Trajektorien aus Windfeldern berechnet. Können zwei Messungen im Rahmen bestimmter Qualitätskriterien durch eine Trajektorie verbunden werden, kann die Ozondifferenz zwischen beiden Sondierungen berechnet und als chemischer Ozonabbau interpretiert werden. Eine solche Koinzidenz wird Match genannt. Der Matchmethode liegt ein statistischer Ansatz zugrunde, so dass eine Vielzahl solcher doppelt beprobter Luftmassen vorliegen muss, um gesicherte Aussagen über die Ozonzerstörung gewinnen zu können. So erhält man die Ozonzerstörung in einem bestimmten Zeitintervall, also Ozonabbauraten. Um die Anzahl an doppelt beprobten Luftpackten zu erhöhen wurde eine aktive Koordinierung der Ozonsondenaufstiege entwickelt. <br><br> Im Rahmen dieser Arbeit wurden Matchkampagnen während des arktischen Winters 2002/2003 und zum ersten Mal während eines antarktischen Winter (2003) durchgeführt. Aus den gewonnenen Daten wurden Ozonabbauraten in beiden Polarwirbeln bestimmt. Diese Abbauraten dienen zum einen der Evaluierung von Modellen, ermöglichen aber auch den direkten Vergleich von Ozonabbauraten in beiden Polarwirbeln. <br><br> Der Winter 2002/2003 war zu Beginn durch sehr tiefe Temperaturen in der mittleren und unteren Stratosphäre charakterisiert, so dass die Matchkampagne Ende November gestartet wurde. Ab Januar war der Polarwirbel zeitweise stark dynamisch gestört. Die Kampagne ging bis Mitte März. Für den Höhenbereich von 400 bis 550 K potentieller Temperatur (15-23 km) konnten Ozonabbauraten und der Verlust in der Gesamtsäule berechnet werden. Die Ozonabbauraten wurden in verschiedenen Tests auf ihre Stabilität überprüft. <br> Der antarktische Polarwirbel war vom Beginn des Winters bis Mitte Oktober 2003 sehr kalt und stellte Ende September kurzzeitig den Rekord für die größte bisher aufgetretene Ozonloch-Fläche ein. Es konnten für den Kampagnenzeitraum, Anfang Juni bis Anfang Oktober, Ozonabbauraten im Höhenbereich von 400 bis 550 K potentieller Temperatur ermittelt werden. Der zeitliche Verlauf des Ozonabbaus war dabei auf fast allen Höhenniveaus identisch. Die Zunahme des Sonnenlichtes im Polarwirbel mit der Zeit führt zu einem starken Anwachsen der Ozonabbauraten. Ab Mitte September gingen die Ozonabbauraten auf Null zurück, da bis zu diesem Zeitpunkt das gesamte Ozon zwischen ca. 14 und 21 km zerstört wurde. <br><br> Im letzten Teil der Arbeit wird ein neuer Algorithmus auf Basis der multivariaten Regression vorgestellt, mit dem Ozonabbauraten aus Ozonprofilen verschiedener Sensoren gleichzeitig berechnet werden können. Dabei können neben der Ozonabbaurate die systematischen Fehler zwischen den einzelnen Sensoren bestimmt werden. Dies wurde exemplarisch am antarktischen Winter 2003 für das 475 K potentielle Temperatur Niveau gezeigt. Neben den Ozonprofilen der Sonden wurden Daten von zwei Satellitenexperimenten verwendet. Die mit der multivariaten Matchtechnik berechneten Ozonabbauraten stimmen gut mit den Ozonabbauraten der Einzelsensor-Matchansätze überein. / <br>The subject of this thesis is the destruction of ozone in the stratospheric polar vortex of the Arctic and Antarctic. It is caused by decomposition products of anthropogenic emitted Chlorofluorocarbons and Halons, radicals of chlorine and bromine. Studies which are dealing with the comparison of measured and modelled ozone loss show that the processes are known but that the quantitative development is not fully understood yet. <br><br> The processes that lead to ozone destruction are similar in both polar vortices. But as a consequence of different meteorological conditions the chemical ozone loss in the arctic polar vortex is less dramatic than over the Antarctic. On average the Arctic polar vortex is stronger perturbed and exhibit a stronger annual variability. In order to distinguish between chemical ozone loss and the dynamical redistribution of ozone in the Arctic vortex the Match method was developed. Air parcels in the polar vortex are probed several times in order to quantify the chemical change in ozone. To identify those air parcels trajectories are calculated using wind fields. When it is possible to connect two measurements by a trajectory within certain quality criteria the difference in ozone can be calculated and is interpreted as chemical ozone loss. Such a coincidence is called a Match. The Match method is a statistical approach which needs many of those doubly probed air parcels in order to draw significant conclusions about the destruction of ozone. So the ozone destruction can be calculated for a certain period in time which gives ozone loss rates. In order to enhance the number of doubly probed air masses an active coordination was established. <br><br> Within the scope of the thesis Match campaigns were performed during the Arctic winter 2002/2003 and for the first time during the Antarctic winter 2003. The achieved data was used in order to determine ozone loss rates in both polar vortices. The loss rates serve for the evaluation of numerical models but allow as well the direct comparison of ozone loss rates of both polar vortices. <br><br> The beginning of the winter 2002/2003 is characterized by very low temperatures in the middle and lower stratosphere. Hence, the Match campaign started at the end of November. From January on the polar vortex was strongly dynamically disturbed at certain times. For the height region of 400 to 500 K potential temperature (15-23 km) ozone loss rates and the column loss were determined. The robustness of the ozone loss rates was checked with a variety of different tests. <br><br> From beginning of the winter until October 2003 the Antarctic polar vortex was very cold and the expansion of the ozone hole area reached record values in late September. From the beginning of June until the beginning of October ozone loss has been calculated in a height region from 400 to 550 K potential temperature. The development of the ozone loss was almost identical on the different height levels. The increase in sunlight led to an increase in ozone loss rates. From mid September the ozone loss rates decreased rapidly and the ozone was completely destroyed between approx. 14 and 21 km. <br><br> In the last part of the thesis a new algorithm is presented which is based on a multivariate regression in order to calculate ozone loss rates from ozone profiles made by different sensors. At the same time the systematic error between different sensors has to be considered. As an example the approach is shown for the Antarctic Winter 2003 on the 475 K potential temperature level. Beside the ozone profiles from the sondes, data from two satellites experiments have been used. The agreement between the ozone loss rates calculated by the multivariate regression method and those calculated by the single match approach is very good.
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Der Einfluss der Dynamik auf die stratosphärische Ozonvariabilität über der Arktis im Frühwinter / Dynamical influence on stratospheric ozone variability over the Arctic in early winter

Bleßmann, Daniela January 2010 (has links)
Der frühwinterliche Ozongehalt ist ein Indikator für den Ozongehalt im Spätwinter/Frühjahr. Jedoch weist dieser aufgrund von Absinkprozessen, chemisch bedingten Ozonabbau und Wellenaktivität von Jahr zu Jahr starke Schwankungen auf. Die vorliegende Arbeit zeigt, dass diese Variabilität weitestgehend auf dynamische Prozesse während der Wirbelbildungsphase des arktischen Polarwirbels zurückgeht. Ferner wird der bisher noch ausstehende Zusammenhang zwischen dem früh- und spätwinterlichen Ozongehalt bezüglich Dynamik und Chemie aufgezeigt. Für die Untersuchung des Zusammenhangs zwischen der im Polarwirbel eingeschlossenen Luftmassenzusammensetzung und Ozonmenge wurden Beobachtungsdaten von Satellitenmessinstrumenten und Ozonsonden sowie Modellsimulationen des Lagrangschen Chemie/Transportmodells ATLAS verwandt. Die über die Fläche (45–75°N) und Zeit (August-November) gemittelte Vertikalkomponente des Eliassen-Palm-Flussvektors durch die 100hPa-Fläche zeigt eine Verbindung zwischen der frühwinterlichen wirbelinneren Luftmassenzusammensetzung und der Wirbelbildungsphase auf. Diese ist jedoch nur für die untere Stratosphäre gültig, da die Vertikalkomponente die sich innerhalb der Stratosphäre ändernden Wellenausbreitungsbedingungen nicht erfasst. Für eine verbesserte Höhendarstellung des Signals wurde eine neue integrale auf der Wellenamplitude und dem Charney-Drazin-Kriterium basierende Größe definiert. Diese neue Größe verbindet die Wellenaktivität während der Wirbelbildungsphase sowohl mit der Luftmassenzusammensetzung im Polarwirbel als auch mit der Ozonverteilung über die Breite. Eine verstärkte Wellenaktivität führt zu mehr Luft aus niedrigeren ozonreichen Breiten im Polarwirbel. Aber im Herbst und Frühwinter zerstören chemische Prozesse, die das Ozon ins Gleichgewicht bringen, die interannuale wirbelinnere Ozonvariablität, die durch dynamische Prozesse während der arktischen Polarwirbelbildungsphase hervorgerufen wird. Eine Analyse in Hinblick auf den Fortbestand einer dynamisch induzierten Ozonanomalie bis in den Mittwinter ermöglicht eine Abschätzung des Einflusses dieser dynamischen Prozesse auf den arktischen Ozongehalt. Zu diesem Zweck wurden für den Winter 1999–2000 Modellläufe mit dem Lagrangesche Chemie/Transportmodell ATLAS gerechnet, die detaillierte Informationen über den Erhalt der künstlichen Ozonvariabilität hinsichtlich Zeit, Höhe und Breite liefern. Zusammengefasst, besteht die dynamisch induzierte Ozonvariabilität während der Wirbelbildungsphase länger im Inneren als im Äußeren des Polarwirbels und verliert oberhalb von 750K potentieller Temperatur ihre signifikante Wirkung auf die mittwinterliche Ozonvariabilität. In darunterliegenden Höhenbereichen ist der Anteil an der ursprünglichen Störung groß, bis zu 90% auf der 450K. Innerhalb dieses Höhenbereiches üben die dynamischen Prozesse während der Wirbelbildungsphase einen entscheidenden Einfluss auf den Ozongehalt im Mittwinter aus. / The ozone amount in early winter provides an indication of the ozone amount in late winter/early spring. The early winter amount is highly variable from year to year due to modification by subsidence, chemical loss and wave activity. This thesis shows that this variability is mainly caused by the dynamics during the Arctic polar vortex formation. Furthermore, it explains the still missing link between early and late winter ozone amount due to dynamics and chemistry. Observational ozone data from satellite based instruments, ozone probes and simulations are used for the investigation of the connection between the composition of the air and the ozone enclosed in the polar vortex. The simulations are calculated with the Lagrangian chemistry/transport model ATLAS. The over area (45–75°N) and time (August-November) averaged vertical component of the Eliassen-Palm flux at 100hPa points to a link between the early winter composition of the air enclosed in the polar vortex and the vortex formation phase. This is only valid for the lower stratosphere, because the component does not satisfy changing conditions for wave propagation throughout the stratosphere by itself. Due to this deficit a new integral quantity based on wave amplitude and properties of the Charney-Drazin criterion is defined to achieve an improvement with height. This new quantity connects the wave activity during vortex formation to the composition of air inside the vortex as well as the distribution of ozone over latitude. An enhanced wave activity leads to a higher proportion of ozone rich air from lower latitudes inside the polar vortex. But chemistry in autumn and early winter removes the interannual variability in the amount of ozone enclosed in the vortex induced by dynamical processes during the formation phase of the Artic polar vortex because ozone relaxes towards equilibrium. An estimation of how relevant these variable dynamical processes are for the Arctic winter ozone abundances is obtained by analysing which fraction of dynamically induced anomalies in ozone persists until mid winter. Model runs with the Lagrangian Chemistry-Transport-Model ATLAS for the winter 1999–2000 are used to assess the fate of ozone anomalies artificially introduced during the vortex formation phase. These runs provide detailed information about the persistence of the induced ozone variability over time, height and latitude. Overall, dynamically induced ozone variability from the vortex formation phase survives longer inside the polar vortex compared to outside and can not significantly contribute to mid-winter variability at levels above 750K potential temperature level. At lower levels increasingly larger fractions of the initial perturbation survive, reaching 90% at 450K potential temperature level. In this vertical range dynamical processes during the vortex formation phase are crucial for the ozone abundance in mid-winter.
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Μελέτη αποδόμησης των πολυκυκλικών αρωματικών υδρογονανθράκων (PAHs) με χρήση όζοντος / Degradation of polycyclic aromatic hydrocarbons (PAHs) with ozon

Καρκαλέτσης, Θαλάσσης 28 June 2007 (has links)
Ο στόχος την παρούσας εργασίας είναι η αποδόμηση των PAHs με χρήση όζοντος.Για το σκοπό αυτό επιλέξαμε το φαινανθρένιο ως ένωση-μοντέλο σε οργανικό διαλύτη, με απώτερο στόχο την επεξεργασία επικίνδυνων αποβλήτων. / The perpose of this study is the degradation of polycyclic aromatic hydrocarbons with ozon. For this reason we use phenanthrene like model-compound in organic solution.

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