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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.
81

Towards Christianity without authority : pluralism, skepticism, and ecclesiastical power in selected examples of humorous Newfoundland writing

Fralic, Michael Lloyd 02 February 2007
In recent decades in Newfoundland, a sustained interest in Christian symbols, stories, and values has been paired with increasing criticism of Christian religious institutions and agents. Newfoundlands burgeoning tradition of professional humour has reflected this changing set of relationships to Christianity. This robust young humour tradition richly reflects the ongoing pluralization and secularization of Newfoundland culture, and abundantly exemplifies humours distinctive potential as a means of addressing potentially contentious or vexing issues. Yet, surprisingly, literary criticism has almost entirely avoided the prominent stream of Newfoundland humour that addresses the islands religious legacy.<p>This project aims to begin to correct this substantial critical omission, examining points of continuity among a number of works produced over the past four decades. It focuses on the works embrace of political and/or epistemological pluralism, typically married to religious skepticism and to misgivings about conventional arrangements of religious power. Chapter One provides an historical and critical context for the project, introduces subsequent chapters, and speculates on ramifications of the pluralistic current that runs through the works in the study. Chapter Two examines religious jokes in Newfoundland joke books. It emphasizes the jokes overall tendency toward (an often ambiguous) religious conservatism, as well as the books latent pluralism regarding interdenominational relations. Chapter Three focuses on journalist and playwright Ray Guys often fierce satire of Christian religious agents and institutions. It argues that Guys satire utterly rejects the legitimacy of religious authority in the civic realm, largely on the grounds that transcendent truthfulness is often invoked as a means of justifying otherwise objectionable power. Chapter Four explores the ecumenical religious humour of columnist and memoirist Ed Smith. It focuses on Smiths playful efforts to harmonize Christian faith and practice with a measure of religious uncertainty presented as a necessary foundation for humane coexistence. Chapter Five examines Ed Kavanaghs novel The Confessions of Nipper Mooney. Primarily, it explicates and examines the novels liberal favouring of the individual moral conscience, and the symbolic association of its religiously dissident and/or marginalized protagonists with elements of the Catholic tradition. Chapter Six discusses Berni Stapletons comic play The Pope and Princess Di. The chapter emphasizes the plays presentation of symbols constant subjection to alteration and hybridization, and its cautious regard for valuable symbols (religious or otherwise) that nonetheless become destructive when viewed as sacrosanct.<p>Chapter Seven concludes the study by considering the works participation in political, philosophical, and literary/dramatic movements that problematize long-established religious modes and support a secular-pluralist outlook. It reflects on the role of humour in movements for change and on didacticism and popular humour as features of publicly engaged literature; it discusses other works of Newfoundland humour that approach religious matters from similarly secular, though less overtly political, angles; and it speculates on some social implications of the ascendancy of liberal, pluralistic values, considering these Newfoundland works in a more general Canadian cultural context.
82

Towards Sustainable Phosphorus Management : Material Flow Analysis of phosphorus in Gothenburg and ways to establish nutrient recycling by improving urban wastewater systems / Mot en mer hållbar fosforhantering : Substansflödesanalys av fosfor i Göteborg och sätt att uppnå näringsåtervinning genom att förbättra urbana avloppssystem

Borgestedt, Helena, Svanäng, Ingela January 2011 (has links)
All life forms require the nutrient phosphorus and it cannot be substituted by any other element. The global cycle of phosphorus is special among the major biogeochemical cycles, since it has no significant gaseous compounds and only closes every 10-100 million years. However, human activities, as application of mineral fertilizers, conversion of natural ecosystems to arable land and releases of untreated waste, intensify remarkably thephosphorus flows. The problems with linear flows of a limited resource leading to eutrophication of aquaticenvironments, for instance, have generated national environmental quality objectives for phosphorus in Sweden. The main objective of this master thesis is to get a holistic overview of how phosphorus is moving through Gothenburg today, using Material Flow Analysis as method. The spatial system boundary is the municipality of Gothenburg and the temporal system boundary is the year of 2009. One way of dealing with the linear flows ofphosphorus might be to develop the wastewater systems used in Gothenburg today. Possible changes in phosphorus flows, if kitchen grinders or urine-diverting toilets were installed in Gothenburg, are evaluated. In order to make the phosphorus management more sustainable, the linear flows have to be closed to a larger extent than today. One way towards this ambition is to emphasize other fertilizers than the mineral ones, like urine and low-contaminated sludge. The MFA shows that the absolutely largest input of phosphorus to Gothenburg is via the food. The two large outputs of the same magnitude are the digested sludge from the wastewater treatment plant of Rya and the ashes from the waste-fuelled district heating power plant of Sävenäs. About 7% of the phosphorus input to Gothenburg continues into the aquatic environment. According to this study, urine diversion and separate collection of food seem prospective in order to decrease the phosphorus flows in digested sludge from the wastewater treatment plant, ashes and aquatic deposition. An additional advantage would be generation of recycled fertilizing products with good quality. / Näringsämnet fosfor är nödvändigt för alla levande organismer och kan inte ersättas av något annat grundämne. Den globala fosforcykeln är speciell då den inte innehåller några gasformiga föreningar och sluts var 10-100 miljonte år. Användning av konstgödsel, omvandling av tidigare orörda ekosystem till odlingsmark och utsläppav förorenat avfall är exempel på mänskliga aktiviteter som intensifierar fosforflöden. Problemet med att linjäraflöden av denna begränsade resurs leder till övergödning av vattenmiljöer har genererat nationella miljömål i Sverige för fosfor. Det huvudsakliga målet med detta examensarbete är att få en översikt av hur fosfor rör sig genom Göteborg idag med hjälp av substansflödesanalys. Den rumsliga systemgränsen är kommungränsen för Göteborg och den tidsmässiga avgränsningen är året 2009. Ett sätt att förbättra de linjära fosforflödena kan vara att utveckla deavloppssystem som idag används i Göteborg. Förändringarna som uppstår i fosforflödena vid installation av urinsorterande toaletter alternativt köksavfallskvarnar undersöks. Linjära flöden måste bli återcirkulerade i en högre utsträckning än idag ifall fosforhushållningen ska gå mot hållbarhet. Ett sätt att nå denna ambition är att lyfta fram andra gödselprodukter än konstgödsel, exempelvis urin och renare slam. Flödesanalysen visar att det definitivt största inflödet av fosfor till Göteborg är via livsmedel. De två största fosforutflödena, båda i samma storleksordning, är rötat slam från Ryaverket och aska från sopförbränningsanläggningen Sävenäs. Cirka 7% av den fosfor som flödar in i Göteborg fortsätter vidare ut i vattenmiljön. Enligt denna studie verkar urinsortering och separat insamling av matavfall vara goda lösningar för en framtid med mindre fosfor i slammet från Rya och i aska samt till vattenmiljön. En ytterligare fördel skulle vara erhållandet av hållbara gödselprodukter med god kvalitet. / <p>This master thesis has also been published as a technical report at Chalmers with Report No. 2011:124.</p>
83

Towards Christianity without authority : pluralism, skepticism, and ecclesiastical power in selected examples of humorous Newfoundland writing

Fralic, Michael Lloyd 02 February 2007 (has links)
In recent decades in Newfoundland, a sustained interest in Christian symbols, stories, and values has been paired with increasing criticism of Christian religious institutions and agents. Newfoundlands burgeoning tradition of professional humour has reflected this changing set of relationships to Christianity. This robust young humour tradition richly reflects the ongoing pluralization and secularization of Newfoundland culture, and abundantly exemplifies humours distinctive potential as a means of addressing potentially contentious or vexing issues. Yet, surprisingly, literary criticism has almost entirely avoided the prominent stream of Newfoundland humour that addresses the islands religious legacy.<p>This project aims to begin to correct this substantial critical omission, examining points of continuity among a number of works produced over the past four decades. It focuses on the works embrace of political and/or epistemological pluralism, typically married to religious skepticism and to misgivings about conventional arrangements of religious power. Chapter One provides an historical and critical context for the project, introduces subsequent chapters, and speculates on ramifications of the pluralistic current that runs through the works in the study. Chapter Two examines religious jokes in Newfoundland joke books. It emphasizes the jokes overall tendency toward (an often ambiguous) religious conservatism, as well as the books latent pluralism regarding interdenominational relations. Chapter Three focuses on journalist and playwright Ray Guys often fierce satire of Christian religious agents and institutions. It argues that Guys satire utterly rejects the legitimacy of religious authority in the civic realm, largely on the grounds that transcendent truthfulness is often invoked as a means of justifying otherwise objectionable power. Chapter Four explores the ecumenical religious humour of columnist and memoirist Ed Smith. It focuses on Smiths playful efforts to harmonize Christian faith and practice with a measure of religious uncertainty presented as a necessary foundation for humane coexistence. Chapter Five examines Ed Kavanaghs novel The Confessions of Nipper Mooney. Primarily, it explicates and examines the novels liberal favouring of the individual moral conscience, and the symbolic association of its religiously dissident and/or marginalized protagonists with elements of the Catholic tradition. Chapter Six discusses Berni Stapletons comic play The Pope and Princess Di. The chapter emphasizes the plays presentation of symbols constant subjection to alteration and hybridization, and its cautious regard for valuable symbols (religious or otherwise) that nonetheless become destructive when viewed as sacrosanct.<p>Chapter Seven concludes the study by considering the works participation in political, philosophical, and literary/dramatic movements that problematize long-established religious modes and support a secular-pluralist outlook. It reflects on the role of humour in movements for change and on didacticism and popular humour as features of publicly engaged literature; it discusses other works of Newfoundland humour that approach religious matters from similarly secular, though less overtly political, angles; and it speculates on some social implications of the ascendancy of liberal, pluralistic values, considering these Newfoundland works in a more general Canadian cultural context.
84

Mise Eire : national and personal identity in two recent Irish memoirs.

Stobie, Melissa Lauren. January 2001 (has links)
Chapter One will outline the way I will be using the constructs of "national" and "personal" identity, and will then move on to provide a brief contextual setting for the creation and importance of certain literary conventions of Irish topography and character, in particular by examining the cultural nationalism in Yeats's poems. In doing so, I will outline the metaphor of evolution which is crucial in this dissertation, and will examine some of the ethical implications of employing this metaphor. Chapter Two will examine the 1996 memoir Angela's Ashes by Frank McCourt, outline McCourt's employment of various stock Irish tropes, and show how this leads to a conflation of "personal" and "national" identity, to the detriment of the memoir. Chapter Three will turn to critique Are You Somebody?, the memoir by Nuala O'Faolain which was also published in 1996. I will argue that, in contrast to Angela 's Ashes, Are You Somebody? offers a constructive fusion of both kinds of identity national and personal. In Chapter Four, I will compare and contrast key issues in the texts, in relation to their both being memoirs of (Irish) national significance, published at the same time in a changing Ireland, and I will conclude by arguing that the process of invention which is necessary for the writing of a memoir is equally necessary for the creation of a national identity. / Thesis (M.A.)-University of Natal, Pietermaritzburg, 2001.
85

Class-F Fly Ash and Ground Granulated Blast Furnace Slag (GGBS) Mixtures for Enhanced Geotechnical and Geoenvironmental Applications

Sharma, Anil Kumar January 2014 (has links) (PDF)
Fly ash and blast furnace slag are the two major industrial solid by-products generated in most countries including India. Although their utilization rate has increased in the recent years, still huge quantities of these material remain unused and are stored or disposed of consuming large land area involving huge costs apart from causing environmental problems. Environmentally safe disposal of Fly ash is much more troublesome because of its ever increasing quantity and its nature compared to blast furnace slag. Bulk utilization of these materials which is essentially possible in civil engineering in general and more particular in geotechnical engineering can provide a relief to environmental problems apart from having economic benefit. One of the important aspects of these waste materials is that they improve physical and mechanical properties with time and can be enhanced to a significant level by activating with chemical additives like lime and cement. Class-C Fly ashes which have sufficient lime are well utilized but class-F Fly ashes account for a considerable portion that is disposed of due to their low chemical reactivity. Blast furnace slag in granulated form is used as a replacement for sand to conserve the fast declining natural source. The granulated blast furnace slag (GBS) is further ground to enhance its pozzolanic nature. If GBS is activated by chemical means rather than grinding, it can provide a good economical option and enhance its utilization potential as well. GGBS is latent hydraulic cement and is mostly utilized in cement and concrete industries. Most uses of these materials are due to their pozzolanic reactivity. Though Fly ash and GGBS are pozzolanic materials, there is a considerable difference in their chemical composition. For optimal pozzolanic reactivity, sufficient lime and silica should be available in desired proportions. Generally, Fly ash has higher silica (SiO2) content whereas GGBS is rich in lime (CaO) content. Combining these two industrial wastes in the right proportion may be more beneficial compared to using them individually. The main objective of the thesis has been to evaluate the suitability of the class-F Fly ash/GGBS mixtures with as high Fly ash contents for Geotechnical and Geo-environmental applications. For this purpose, sufficient amount of class-F Fly ash and GGBS were collected and their mixtures were tested in the laboratory for analyzing their mechanical behavior. The experimental program included the evaluation of mechanical properties such as compaction, strength, compressibility of the Fly ash/GGBS mixtures at different proportions with GGBS content varying from 10 to 40 percent. An external agent such as chemical additives like lime or cement is required to accelerate the hydration and pozzolanic reactions in both these materials. Hence, addition of varying percentages of lime is also considered. However, these studies are not extended to chemically activate GBS and only GGBS is used in the present study. Unconfined compressive strength tests have been carried out on various Fly ash/ GGBS mixtures at different proportions at different curing periods. The test results demonstrated rise in strength with increase in GGBS content and with 30 and 40 percent of GGBS addition, the mixture showed higher strength than either of the components i.e. Fly ash or GGBS after sufficient curing periods. Addition of small amount of lime increased the strength tremendously which indicated the occurrence of stronger cementitious reactions in the Fly ash/GGBS mixtures than in samples containing only Fly ash. Improvement of the strength of the Fly ash/GGBS mixtures was explained through micro-structural and mineralogical studies. The microstructure and mineralogical studies of the original and the stabilized samples were investigated by scanning electron microscopy (SEM) and X-Ray diffraction techniques respectively. These studies together showed the formation of cementitious compounds such as C-S-H, responsible for imparting strength to the pozzolanic materials, is better in the mixture containing 30 and 40 percent of GGBS content than in individual components. Resilient and permanent deformation behavior on an optimized mix sample of Fly ash and GGBS cured for 7 day curing period has been studied. The Resilient Modulus (Mr) is a measure of subgrade material stiffness and is actually an estimate of its modulus of elasticity (E). The permanent deformation behavior is also important in predicting the performance of the pavements particularly in thin pavements encountered mainly in rural and low volume roads. The higher resilient modulus values indicated its suitability for use as subgrade or sub-base materials in pavement construction. Permanent axial strain was found to increase with the number of load cycles and accumulation of plastic strain in the sample reduced with the increase in confining pressure. Consolidation tests were carried on Fly ash/GGBS mixtures using conventional oedometer to assess their volume stability. However, such materials develop increased strength with time and conventional rate of 24 hour as duration of load increment which requires considerable time to complete the test is not suitable to assess their volume change behavior in initial stages. An attempt was thus made to reduce the duration of load increment so as to reflect the true compressibility characteristics of the material as close as possible. By comparing the compressibility behavior of Fly ash and GGBS between conventional 24 hour and 30 minutes duration of load increment, it was found that 30 minutes was sufficient to assess the compressibility characteristics due to the higher rate of consolidation. The results indicated the compressibility of the Fly ash/GGBS mixtures slightly decreases initially but increase with increase in GGBS content. Addition of lime did not have any significant effect on the compressibility characteristics since the pozzolanic reaction, which is a time dependent process and as such could not influence due to very low duration of loading. Results were also represented in terms of constrained modulus which is a most commonly used parameter for the determination of settlement under one dimensional compression tests. It was found that tangent constrained modulus showed higher values only at higher amounts of GGBS. It was also concluded that settlement analysis can also be done by taking into account the constrained modulus. The low values of compression and recompression indices suggested that settlements on the embankments and fills (and the structures built upon these) will be immediate and minimal when these mixtures are used. In addition to geotechnical applications of Fly ash/GGBS mixture, their use for the removal of heavy metals for contaminated soils was also explored. Batch equilibrium tests at different pH and time intervals were conducted with Fly ash and Fly ash/GGBS mixture at a proportion of 70:30 by weight as adsorbents to adsorb lead ions. It was found that though uptake of lead by Fly ash itself was high, it increased further in the presence of GGBS. Also, the removal of lead ions increased with increase in pH of the solution but decreases at very high pH. The retention of lead ions by sorbents at higher pH was due to its precipitation as hydroxide. Results of the adsorption kinetics showed that the reaction involving removal of lead by both the adsorbents follow second-order kinetics. One of the major problems which geotechnical engineers often face is construction of foundations on expansive soils. Though stabilization of expansive soils with lime or cement is well established, the use of by-product materials such as Fly ash and blast furnace slag to achieve economy and reduce the disposal problem needs to be explored. To stabilize the soil, binder comprising of Fly ash and GGBS in the ratio of 70:30 was used. Different percentages of binder with respect to the soil were incorporated to the expansive soil and changes in the physical and engineering properties of the soil were examined. Small addition of lime was also considered to enhance the pozzolanic reactions by increasing the pH. It was found that liquid limit, plasticity index, swell potential and swell pressure of the expansive soil decreased considerably while the strength increased with the addition of binder. The effect was more pronounced with the addition of lime. Swell potential and swell pressure reduced significantly in the presence of lime. Based on the results, it can be concluded that the expansive soils can be successfully stabilized with the Fly ash-GGBS based binder with small addition of lime. This is also more advantageous in terms of lime requirement which is typically high when Fly ash, class-F in particular, is used alone to stabilize expansive soils. Based on the studies carried out in the present work, it is established that combination of Fly ash and GGBS can be advantageous as compared to using them separately for various geotechnical applications such as for construction of embankments/fills, stabilization of expansive soils etc. with very small amount of lime. Further, these mixtures have better potential for geo-environmental applications such as decontamination of soil. However, it is still a challenge to activate GBS without grinding.
86

Contribution à l'élaboration d'un procédé de valorisation des cendres volantes et des résidus d'épuration des fumées d'incinération d'ordures ménagères / Valorisation of municipal solid waste incineration fly ashes and air pollution control residues

De Boom, Aurore 04 November 2009 (has links)
D’après les limites d’acceptation pour la mise en décharge des déchets, les REFIOM (Résidus d’Epuration des Fumées d’Incinération d’Ordures Ménagères) sont considérés comme déchets dangereux, car ils libèrent des quantités importantes de chlorures et de métaux lourds lorsqu’ils entrent en contact avec de l’eau. Ces solides doivent par conséquent être traités avant leur mise en décharge. A côté des traitements visant l’acceptabilité des REFIOM en décharge, quelques recherches entrevoient la possibilité de valoriser ces résidus, notamment dans des matériaux cimentaires. <p>Les recherches présentées ici s’inscrivent dans cette tendance nouvelle et visent l’élaboration d’un procédé combinant traitement et valorisation des REFIOM. <p>Les REFIOM représentent en fait différents types de résidus provenant des installations que rencontrent les fumées issues de l’incinération des déchets. La composition des résidus diffère selon leur origine. Il est dès lors apparu essentiel de considérer chaque type de résidu séparément et de poursuivre l’élaboration d’un traitement sur un seul type de REFIOM. Nous avons choisi de concentrer les recherches sur les Cendres Volantes de Chaudière (CVC), ces résidus se retrouvant dans tout incinérateur. <p>Le traitement des CVC est basé sur l’extraction de fractions valorisables et la séparation de fractions contaminées, permettant d’obtenir des résidus acceptables en décharge ou, idéalement eux-mêmes valorisables. <p>Une séparation magnétique permet d’extraire environ 10% en poids des CVC mais ne semble pas exploitable dans le cadre du traitement des CVC car les particules magnétiques contiennent des impuretés (composés non magnétiques) et que le résidu final reste contaminé. <p>Une étude de la répartition des éléments en fonction de la taille des particules (granulochimie) est effectuée sur les CVC. Il apparaît intéressant de séparer la fraction inférieure à 38 µm obtenue lors d’une séparation granulométrique, effectuée en voie humide en utilisant une solution dense. En effet, cette fraction semble être nettement plus contaminée en Pb (soluble) que le reste des CVC. Une telle séparation constitue dès lors la première étape du traitement des CVC. Elle est suivie par des étapes de lavage des fractions obtenues, visant à extraire les sels solubles (chlorures et métaux). Les lavages sont envisagés à contre-courant afin d’utiliser au mieux l’eau de lavage. Une recirculation interne des solutions est également prévue, de sorte que, théoriquement, le procédé ne génère pas d’effluents liquides. Une étape de précipitation de composés métalliques (PbS dans ce cas-ci) est prévue après le lavage des boues. <p>Le procédé de traitement des CVC produirait ainsi des boues et des granulats décontaminés, des sels et des précipités métalliques. Seules certaines étapes du procédé ont été investiguées en laboratoire ;des essais supplémentaires sont encore nécessaires pour optimiser chaque étape, comprendre les phénomènes physico-chimiques qui se produisent et assurer des filières de valorisation. <p>/<p>Municipal Solid Waste Incineration (MSWI) fly ashes and Air Pollution Control (APC) residues are considered as hazardous waste according to the limits for the acceptance of waste at landfills, because high amounts of chlorides and heavy metals leach from the solids when those are in contact with water. These residues have thus to be treated before they can be accepted in landfill. Several treatments aim to limit the leaching of the residues. Beside these treatments, some research works go further the treatment and consider the valorisation of MSWI fly ashes and APC residues, e.a. in cementitious materials. <p>The present work follows the new trend and aims to build up a process that combines treatment and valorisation of MSWI fly ashes and APC residues. <p>MSWI fly ashes and APC residues come from the devices encountered by the flue gases from waste incineration. The residues composition differs according to their origin. It seems thus essential to consider each type of residues separately and to develop the treatment only on one sort of residue. Boiler Fly Ashes (BFA) were chosen because they exist in every modern MSWI plant. <p>The BFA treatment is based on the extraction of valorisable fractions and on the separation of contaminated fractions, which makes the final residues less hazardous; these final residues would then be acceptable in landfill, or, even better, be valorisable. <p>A magnetic sorting extracts ~10% (wt.) of BFA; however, such a separation would not be useful in a treatment process because the magnetic particles contain some impurities (non magnetic particles) and the final residue is still hazardous. <p>The repartition of the elements according to the particles size has been studied on BFA. It seems interesting to separate the BFA at 38 µm by a wet sieving process using a dense solution. The lower fraction presents a higher contamination in Pb (soluble) than the larger. Consequently, the first step of the BFA treatment consists of a wet sieving. Washing steps follow the sieving and aim to extract soluble salts (chlorides, heavy metals). These washings work in a counter-current way to optimise the use of water. The solutions are recycled in the process, which implies the absence of liquid effluents. A precipitation step of some metallic compounds (PbS in this case) is foreseen after the washing of the lower fraction. <p>The BFA treatment process would produce decontaminated sludge and coarse fractions, salts and metallic compounds. Some steps of the process have been investigated at lab-scale; further studies are necessary to optimise each step, to understand the observed reactions and to guarantee valorisation channels. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished
87

Impact de la chimie des poussières minérales sur la photochimie atmosphérique / Impact of mineral dust photochemistry on the atmosphere

Dupart, Yoan 19 December 2012 (has links)
Les travaux de cette thèse reposent sur l’étude des processus hétérogènes à la surface desparticules minérales en présence d’irradiation UV-A. Nous savons que les poussièresminérales contiennent des oxydes métalliques pouvant absorber la radiation solaire et ainsiactiver une chimie très différente de celle observée à l’obscurité. Un réacteur à écoulementd’aérosols a été utilisé pour étudier les interactions des gaz (SO2, NO2 et O3) avec devéritables poussières minérales, évitant ainsi les artéfacts de mesure liés à la naturemacroscopique des films comme dans les études précédentes.La mise en suspension des poussières minérales a permis d’observer une formation inattenduede nouvelles particules ultrafines en présence de SO2. Le mécanisme proposé pour expliquerce phénomène de nucléation suggère une désorption de radicaux OH photoproduits à lasurface des minéraux vers la phase gazeuse. Ce mécanisme a pu être corroboré par descampagnes de mesure en atmosphère réelle. Nous avons étudié la chimie des échantillons de réelles cendres volcaniques issus de la dernière éruption du volcan Eyjafjallajökull en Islande (2010). Ceci nous a permis d’élaborerdes cinétiques de capture du SO2 sur des films macroscopiques de cendres aboutissant à descoefficients de capture de l’ordre de 10-7. Ces cinétiques couplées à des analyses chimiquesont permis de proposer un mécanisme réactionnel expliquant la formation de sulfate de fer àla surface des cendres. Finalement, nous avons étudié les interactions photochimiques de O3 et NO2 sur les poussièresminérales dans le réacteur à écoulement mettant en évidence un bon accord avec des étudesantérieures sur des surfaces macroscopiques / The objective of this work is to study the heterogeneous processes of mineral dust surfacesunder UV-A radiation. It is know that mineral dust containing metal oxides which can absorbsolar radiation and therefore activate a different chemistry compared to that observed in thedark. In order to avoid measurement artifacts related to the nature of macroscopic films, anaerosol flow tube was developed during this work and applied to study the interactions ofSO2, NO2 and O3 with real mineral dust.An unexpected formation of new particles in the presence of SO2 was observed. In order toexplain this phenomenon, we suggest the desorption of OH radicals from the mineral dustsurface to the gas phase. This mechanism has also been supported by field campaigns.Using real samples of volcanic ash from the last eruption of Eyjafjallajökull in Iceland (2010)allowed us study capture of SO2 on macroscopic ashes films with uptake coefficient around10-7. Associated kinetic experiments combined with chemical analysis allowed us to propose areaction mechanism explaining the formation of iron sulfate on the surface of ashes.Finally, we investigated the photochemical interactions of O3 and NO2 with minerals dustaerosols in the flow tube reactor showing a good agreement with previous data obtained onmacroscopic surfaces.
88

Traitement à haute pression et haute température de déchets de métaux lourds vers de nouveaux matériaux stables / High pressure and high temperature treatment of heavy metal waste, towards new stable materials

Karnis, Aurélie 08 October 2009 (has links)
Les REFIOM (Résidus d'Epuration des Fumées d'Incinération des Ordures Ménagères) issus de l'incération des déchets ménagers contiennent des métaux lourds comme le plomb ou le cadmium et sont en France uniquement stockés en centre d'enfouissement technique de classe 1 pour dangereux, en étant stabilisés par une vitrification. Afin de trouver des solutions pour le stockage ou la valorisation à long terme des REFIOM sans danger pour l'environnement, nous avons ciblé les vitrocéramiques et les céramiques frittées à hautes températures et hautes pressions. Nous avons utilisé des méthodes de la minéralogie physique par l'intermédiaire de synthèses à hautes températures, de synthèses à hautes températures et à hautes pressions en autoclave à chauffage externe, d'observations en microscopie électronique à balayage, de microanalyses chimiques EDX (Energy Dispersive X-Ray spectrometry), d'analyses en microsondes, de caractérisation structurale par diffraction de rayons X et d'expériences de lixiviation dynamique. Nous avons mis au point des protocoles de synthèses et d'analyses. Par ce biais, nous constatons pour les vitrocéramiques que le plomb ou le cadmium sont incorporés dans des cristallites et dans des nouvelles phases cristallines, eux-mêmes englobés dans une matrice vitreuse. Cette voie dite "double barrière" (cristaux + verre) semble prometteuses pour l'immobilisation du plomb et du cadmium (au regard des analyses EDX et des expériences de lixiviation). Pour les céramiques frittées, comme pour les SYNROC (SYNthetic ROCk) synthétisées pour les déchets nucléaires, de nouvelles phases cristallines incorporant Pb et Cd sont observées et seraient a priori résistantes pour le stockage de ces éléments toxiques. Dans ces deux cas de nouveaux matériaux capables d'incorporer massivement du plomb et du cadmium ont été mis en évidence. Des tests de durabilité permettront d'envisager une valorisation éventuelle de tels matériaux / MSWI 5Municipal Solide Waste Incinerator) fly ashes from the incineration of domestic waste contain heavy metals such as lead or cadmium. In France, these fly ashes are only stored under vitrified forms in class-1 type landfills for hazardous waste. In order to find solutions for long-term storage or valorization of the MSWI fly ashes, we studied glass-ceramics and sintered ceramics at high pressures and/or hight temperature. We used methods of mineral physics to : synthetize at high temperature, synthetize at higt temperature and high pressure using autoclaves with external heating system, observe by electron microcopy, make EDX (Energy Dispersive X-Ray spectrometry) chemical microanalysis, make microprobe analysis, structurally characterize and perform leaching test. We established experimental protocols for the synthesis and analysis of produced materials. For glass-ceramics, we observe that lead and cadmium are incorporated inside expected crystallites and new crystal phases, themselves embedded by a glassy matrix. This so-called "double barrier" (crystals + glass) is a promising way towards a substainable of lead and cadmium (after EDX analysis and leaching experiements). For sintered ceramics, as for the SYNROC (SYNthetic ROCk) with nuclear waste, new crystal phases incorporating Pb and Cd are found and might display a high resistant for the storage of these toxic elements. In both cases, new materials incorporating large amounts of lead and cadmium were formed. Durability tests may give new ways for a valorization of such materials
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Kurita : CARING FOR SOIL

García Portolés, Andrea January 2023 (has links)
Soil is one of the largest ecosystems being ignored by human activities. Our farming practices and urban constructions have contributed to its degradation, with far-reaching consequences for the water cycle’s equi- librium.Reconnect with nature and learn the methods to assist in its recovery are essential for the survival of all inhabitants on this planet.  My degree project consists of a large research into the water cycle of urban areas, studying the particular case of Stockholm, that leads to the problems of degraded soil. The aim is to understand the relation- ship between water cycle and soil ecosystems and explore potential solutions.  As a result, I have designed KURITA, a learning tool founded upon the ecofeminism values of care, that serves as a learning method for citi- zens to reconnect with soil values and actively participate in its restor- ative process.
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The effect of wood ash on the soil properties and nutrition and growth of Eucalyptus grandis x urophylla grown on a sandy coastal soil in Zululand

Scheepers, Gerhardus Petrus 12 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: A field trial of six replications was established to test the effect of various wood ash and fertilisers application rates on soil chemistry, tree nutrition and early growth rate of a clonal Eucalyptus grandis x urophylla stand. Wood ash from pulpmills is currently disposed of in landfills. Increasing costs and potential environmental risks have driven companies to investigate alternative disposal methods. Ash consists of a combination of carbonates, hydroxides and other calcium containing minerals that induce the liming effect if ash is applied to a soil. The trial was established near Richards Bay in October 2013 on a sandy soil with a low buffer capacity and a pH of approximately 5.5. The trial consists of four wood ash application rates in combination with three levels of fertiliser, viz. no fertiliser, 150 g conventional NPK fertiliser mixture, or 320g NPK controlled release mixture. Fertiliser mixtures and application levels were based on previous fertiliser trials in the region. Ash application rates for the field trial were based on a lab incubation study done with soil samples from Richards Bay, to which increasing amounts of lime were added. The study tested wood ash application rates of 0, 300, 600 and 1200 kg/ha. Field measurements were taken at 4 and 8 months after trial establishment. The primary objective was to investigate which application levels in combination with the type of fertiliser could be applied to soils without negatively affecting the stand nutrition or increase the levels of potentially harmful elements in the soil; thus investigating the feasibility of safely disposing wood ash on plantation soils as an alternative disposal method. Soil nutrient concentrations were not affected by individual wood ash treatments, but more a product of the time interval after the ash additions were made. Soil C, P, K+ and Mg2+ showed decreased concentrations from 4-8 months after establishment. Ca2+ concentrations increased in the same time interval. In addition, Na+ and B concentrations decreased from 4-8 months. Soil heavy metal concentrations for Cd, Hg, Cr and Pb, analysed for 0-1200 kg/ha ash rates, were well below toxic levels at both time intervals. Wood ash induced a temporary liming effect. Mean soil pH increased with 0.6 units for the period 0 - 4 months and decreased with 0.4 units at 4 - 8 months after trial establishment. Foliar nutrient analyses and assessment techniques revealed sub-optimal nutrient concentrations for P, K and Zn at 4 and 8 months of age. Concentrations were defined as sub-optimal, as none of the nutrients were below critical levels. Foliar heavy metal concentrations for Cd, Hg, Cr and Pb, measured at both time intervals, were less than 1mg/kg. The small concentrations found in this project were attributed to the low bioavailability of all four elements and were likely a product of the edaphic factors at Richards Bay, which was representative of a large greater portion of the Zululand coastal plain sites. The response in biomass index ranged between 13 % and 683 % relative to the control treatment (A0F0). Results showed that application of purely wood ash, or in combination with a supplementary N and P source increased growth up to 8 months after trial establishment for wood ash applications up to 1200 kg/ha. This project demonstrated that 1200 kg/ha wood ash can safely be disposed of on a typical Zululand coastal sand with little environmental risk and no supressed growth, provided that it is balanced with an appropriate NP fertiliser. / AFRIKAANSE OPSOMMING: ‘n Veldproef met ses herhalings is in Oktober 2013 uitgelê met die doel om die uitwerking van verskillende vlakke hout as en kunsmis toedienings op die grond-voedingstof status, boom-voedingstof status en die groei-tempo van ‘n Eucalyptus grandis x urophylla hibried plantasie te bestudeer. Hout as by pulpmeulens word tans weggegooi op stortingsterreine. Toenemende onkostes vir storting en die omgewingsrisiko’s gebonde aan stortingsterreine, dryf maatskappye om verbeterde en meer omgewingsvriendelike metodes te ondersoek om van die as ontslae te raak. Hout as bestaan uit ‘n reeks karbonate, hidroksiede en kalsium bevattende minerale en is verantwoordelik vir die bekalkingseffek op die grond na toediening. Die veldproef is geleë naby Richardsbaai op ‘n sanderige grond met n lae bufferkapasiteit en pH van ongeveer 5.5. Die proef het vier hout as vlakke getoets, gekombineer met drie vlakke van bemesting: geen, 150g konvensionele landbou kunsmis (CV) óf 320g beheerd-vrystellende kunmis (CRF). Die kunsmismengsels en vlakke van bemesting is gebaseer op bestaande of voltooide bemestingseksperimente in die streek. Hout as vlakke was bereken in gekontroleerde laboratorium toestande en gebaseer op ‘n inkubasie studie met grond monsters verkry vanaf Richardsbaai, waarby toenemende vlakke suiwer landboukalk gevoeg is. Die veldproef het hout as vlakke van 0, 300, 600 en 1200 kg/ha getoets. Veld metings is op 4 en 8 maande na behandeling geneem. Die primêre doelwit van die studie was om te bepaal watter vlak hout as en kunmis kombinasie toegedien kan word, sonder om die grond-voedingstof status negatief te beïnvloed of ‘n potensiële skadelike uitwerking op die plantasie groei te veroorsaak. Die uiteinde van die studie was om die haalbaarheid van hout as toedienings op plantasie gronde te bestudeer relatief tot die huidige praktyk van storting, insluitend die risiko van moontlike skadelike newe-effekte. Grondvoedingstatus was nie beduidend beïnvloed deur individuele hout as toevoegings nie, maar was eerder ‘n funksie van die tydsduur sedert behandeling. Grond koolstof, P anione, K+ en Mg2+ konsentrasies het beduidend afgeneem in die periode van 4 - 8 maande na behandling. Die Ca2+ konsentrasies het toegeneem tussen 4 en 8 maande en terselfdertyd het Na+ en B konsentrasies afgeneem. Die swaarmetaal status, spesifiek vir Cd, Hg, Cr en Pb, vir toevoegings van 0-1200 kg/ha hout as was beduidend laer as toelaatbare vlakke in gronde op albei tydsintervalle. Die hout as het ‘n tydelike toename in grond pH veroorsaak. Die gemiddelde pH het tussen 0 - 4 maande toegeneem met 0.6 eenhede en gedurende 4 - 8 maande afgeem met 0.4 eenhede. Blaarontledings en voedingstof assesseringsmetodes het sub-optimale konsentrasies vir P, K en Zn getoon op die ouderdom van 4 en 8 maande. Voedingstof konsentrasies is as sub-optimaal geklassifiseer, omdat konsentrasies nooit laer as kritieke waardes vir gebreksimptome was nie. Die inhoud van Cd, Hg, Cr en Pb in blare was aansienlik kleiner as 1 mg/kg op albei tydsintervalle. Die merkwaardige lae konsentrasies wat in die projek aangeteken is, word toegekryf aan die lae bio-beskikbaarheid van al vier elemente as gevolg van die edafiese faktore eie aan die Richardsbaai omgewing (en ook aan groot dele van die Zoeloelandse kusvlakte). Die groeireaksie (bepaal as biomassa indeks op ouderdom 8 maande) het gewissel van 13 % - 683 % groter as die kontrole behandeling (A0F0). Resultate het bewys dat toedienings van suiwer hout as, of hout as gekombineer met ‘n addisionele N en P kunsmisbron die groei postief beïnvloed tot op die ouderdom van 8 maande. Die studie het bewys dat 1200 kg/ha hout as veilig toegedien kan word op die sandgronde van die kusgebiede in Zululand, met minimale omgewingsrisiko en geen tekens onderdrukte groei nie, mits dit gebalanseer word met ‘n geskikte NP kunsmisbron.

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