<p> A kinetic and mechanistic study on catalytic decomposition of n- and sec-butyl acetate was carried out. The catalysts were silica-alumina and synthetic zeolites including type A, X, Y and mordenite. The reactions were performed in the temperature region of 140° to 290°C at atmospheric pressure using a fixed-bed flow reactor.</p> <p> The esters decomposed to acetic acid and n-butenes. The isomerization of butenes occurred consecutively. The mechanism of ester decomposition was different from that of pyrolysis. The catalytic activity was effected by acidity, cations and pore size. The Langmuir-Hinshelwood rate equation corresponding to the surface reaction on dual-sites correlated data satisfactorily. Strong adsorption of acetic acid, crystal collapse and the blocking of pores with organic deposit caused aging of catalysts.</p> / Thesis / Doctor of Philosophy (PhD)

<p> The Archean "Loose Pebble Bay" conglomerate, Manitou Lake, northwestern Ontario, contains a variety of clast types, not all of which can be readily ascribed to local lithologies. This study was undertaken to determine the modal clast composition of the conglomerate, and investigate the origin of the clasts. The conglomerate lies near the top of a stratigraphic sequence which includes mafic and felsic volcanic rocks, iron formations, conglomerates, sandstones and argillites. The conglomerate unit itself consists of interbedded conglomerate and sandstone, and probably represents a channel-fill deposit of an ancient submarine fan.</p> <p> Modal percentages of clast types were obtained using a line-intercept method. They indicate that most of the debris in the conglomerate can be reasonably attributed to uplift and erosion of the lateral equivalents of the underlying stratigraphy, except for the granitoid clasts, which have no known origin within the area.</p> <p> Petrographic examinations of the clasts indicate that field identifications must be confirmed with thin section investigations.</p> <p> The modal composition of granitoid clasts was determined utilizing both thin sections and stained slabs. Most of the granitoid clasts are granodiorite, or lie just within the granite field, adjacent to the granodiorite field. Textural studies of the granitoid clasts suggest that gneissic and allotriomorphic-granular textured rocks may have formed by deformation or partial recrystallization along grain boundaries of previously hypidiomorphic-granular rocks. Textures generally indicate intrusive origin and slow cooling, although two granophyric samples may have solidified at relatively shallower depths than the other granitoid rocks.</p> <p> The textures and compositions of most of the granitoid clasts suggest that they were derived from one intrusive body. Intrusion of such a body into the volcanic-sedimentary belt, followed by uplift and erosion, would account for the presence in the "Loose Pebble Bay" conglomerate of granitic clasts and clasts similar to the underlying rocks. However, no evidence of such an intrusion has been found in the Manitou Lake area, and two of the granitoid clasts are noticeably different in composition from the others. The possibility of a pre-existing sialic basement cannot be ruled out.</p> / Thesis / Bachelor of Science (BSc)

Waste is common in Swedish urban environments, most of this waste consists of cigarette butts and snus but some of it is packaging waste. The degradation of packaging waste leads to the spread of microplastics, chemicals, sharp metals, and glass. It also contributes to disorder which can lead to increased crime. Swedish municipalities pay billions (SEK) annually to clean up and the environmental and social effects has an unknown cost on society. This report’s purpose was to investigate how the amount of packaging waste in three different socioeconomic areas and the people living there would be affected by a deposit on all packaging. To achieve this, a field study in Örebro was performed where packaging waste was counted. The results showed that the area with the largest socioeconomic challenges had the most packaging and that plastic and paper packaging were the most common in all areas. The report concludes that less populated areas with socioeconomically beneficial conditions generate more packaging waste than areas with larger populations and less beneficial conditions. As a measure against packaging waste this report proposes introducing a deposit on all packaging. The recycling statistics for packaging with a deposit on indicate that it would be anefficient measure. It might cause a change in behavior which would reduce the presence of packaging waste. This would lead to a reduced spread of microplastics, chemicals, sharp metals and glass, a reduction in disorderand crime while also reducing the costs these problems bring. / Skräp förekommer i svenska urbana miljöer, främst cigarettfimpar och portionssnus men även förpackningar. Förekomsten av skräp som förpackningar orsakar en spridning av mikroplaster, kemikalier, vassa metaller och glas vid nedbrytning. Det leder dessutom till oro och ökad brottsförekomst. Sverige betalar årligen miljarder för uppstädning och ytterligare kostnader tillkommer i och med dess påverkan på samhället och miljön. Bland detta skräp finns förpackningsskräp och rapportens syfte var att undersöka förekomsten av förpackningsskräp i tre socioekonomisktskilda områden för att se hur mängden förpackningsskräp och lokalbefolkningen påverkas om pant på alla förpackningar införs. För att uppnå detta syfte genomfördes en fältundersökning i tre olika socioekonomiska områden i Örebro där mängden förpackningsskräp räknades längs en specifik sträcka. Resultaten visade att förpackningar av plast och cellulosabaserade material var vanligast i alla områden, att majoriteten av förpackningsskräp var från livsmedel och att fler förpackningar med pant förekom i området med mycket goda socioekonomiska förutsättningar. Rapportens slutsatser visar att oavsett områdestyp är förpackningsskräp gjort av plast och cellulosabaserad ematerial vanligast. Dessutom verkar de ekonomiska förutsättningarna i ett område ha en större påverkan på förekomsten av förpackningsskräp än antalet människor som finns i området. Som åtgärd mot förekomsten av förpackningsskräp föreslås pant. Återvinningsstatistiken för förpackningar med pant visar att det skulle vara en effektiv åtgärd som kan leda till en beteendeförändring som minskar förekomsten av förpackningsskräp.Detta leder till en minskad spridning av mikroplaster, kemikalier, vassa metaller och glas. Samtidigt som oron, brottsförekomsten och kostnaderna för landet minskar som en följd av minskad nedskräpning / <p>2023-06-02</p>

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No description available.

Plastics have become an integral part of modern life and global use is expected to grow almost two- fold until 2040. 40% of European demand for plastic raw materials is driven by the packaging industry and being a cheap material, focus on waste management has historically been neglected. Sweden introduced a law on extended producer responsibility in 1994, due to which a national recycling system for plastic packaging was introduced, arranged by the producer owned organisation FTI. By 2017, official data stated that the national recycling rate reached 46%, surpassing the target of 30% recycling. However, this figure has been disputed by both governmental and industry reports stating that the true recycling rate could be as low as 14%. With stricter recycling targets arriving in the upcoming decade, framed by the EU circular economy package, new strategies for managing plastic packaging waste are needed.  Alongside the recycling system arranged by FTI, Sweden also has a national deposit return system for the collection of PET bottles. This system continuously generates higher recycling rates than the FTI system, and extending the deposit return system to include other types of plastic packaging could be a way of reaching future targets for plastic packaging recycling. This thesis aims to evaluate the environmental impact of an extended deposit return system in a comparative LCA, with the recycling system organised by FTI as a baseline scenario (S0). Two scenarios with an extended deposit return system have been developed; one based on the current system for PET bottles with national collection (S1), and one based on reuse practices on a local scale, with take-away packaging from restaurants and cafés (S2). The LCA focuses on three impact categories related to circular economy targets – global warming, terrestrial ecotoxicity and fossil resource scarcity. With little previous research on extended deposit return systems and reuse practices in a Swedish setting, this thesis is a first attempt to explore possible extended deposit return system configurations and their associated environmental impacts.  The results show that S2 generates the lowest environmental impact in the analysed impact categories, whereas S0 generates the highest environmental impact in the analysed impact categories. Production of virgin packaging and incineration of waste packaging are the most contributing processes toward global warming results. For terrestrial ecotoxicity, incineration of packaging along with break wear emissions from transports contributes most. For fossil resource scarcity, production of virgin plastic granulate is the most contributing process.  To reduce the environmental impact of plastic management in Sweden, the results highlight the importance of lowering demand for virgin plastic packaging production and minimising incineration of waste plastic packaging. This can be achieved by increasing reuse practices, increasing collection rates and facilitating greater recycling rates by improving packaging design. An additional conclusion is that access to regional and site-specific data needs to be better, to increase the reliability of studies of Swedish waste management systems. / Användningen av plast har ökat explosionsartat under de senaste 70 åren och är idag en oumbärlig del av samhället. Nära 40% av plastråvaran i Europa går till plastförpackningar, men endast en mindre del av materialet återanvänds eller återvinns på årsbasis. Både inom politik och näringsliv diskuteras därför nya mål för återvinning, för ökad resurseffektivitet och minskad miljöpåverkan. I Sverige har ett producentansvarssystem, samordnat av FTI, funnits för insamling och återvinning av plastförpackningar sedan mitten av 90-talet, och nuvarande mål för plastförpackningsåtervinning är 30%. Den officiellt sammanställda statistiken visar att materialåtervinningsmålet uppnås, men på senare år har flera studier uppmärksammat att det råder dålig förståelse av flödet av plaster i Sverige, och att materialåtervinningsgraden i själva verket kan vara så låg som 14%.  Som ett parallellt insamlingssystem i Sverige finns pantsystemet, dit enbart flaskor av PET får lämnas. Pantsystemet har en högre återvinningsgrad än det system som ordnas av FTI och en utökning av pantsystemet till att inkludera andra typer av plastförpackningar kan vara en möjlig väg öka materialåtervinningsgraden för plastförpackningar i Sverige. Syftet med den här studien är att utvärdera miljöpåverkan från ett utökat pantsystem jämfört med nuvarande system som ordnas av FTI i en jämförande livscykelanalys. FTI:s återvinningssystem har modellerats som ett basscenario (S0). Två scenarier för ett utökat pantsystem har tagits fram, ett på nationell nivå baserat på det nuvarande pantsystemet (S1), och ett som fokuserar på återanvändning av plastförpackningar på lokal nivå (S2). Studien fokuserar på tre effektkategorier som relaterar till övergripande mål inom cirkulär ekonomi – global uppvärmning, marktoxicitet samt användning av fossila resurser.  Resultaten visar att S2 har lägst påverkan i de tre undersökta effektkategorierna, samtidigt som S0 har högst miljöpåverkan i de tre undersökta effektkategorierna. De processer som bidrar mest till effektkategorin global uppvärmning är tillverkning och avfallsförbränning av plastförpackningar. För marktoxicitet bidrar partikelutsläpp från lastbilars bromsar vid transport tillsammans med förbränning av plastförpackningar mest. För användning av fossila resurser är tillverkning av plastgranulat den största bidragande processen. De åtgärder som gör mest nytta i förhållande till att minska miljöpåverkan från hanteringen av plastförpackningar är minskad efterfrågan på plastgranulat genom återanvändning, att undvika förbränning av plastförpackningar genom ökad insamling samt att förbättra möjligheterna till materialåtervinning genom bättre förpackningsdesign.

Utsläppskontroll, reglerad av allt strängare lagstiftning, ställer höga krav på utvecklingen av noggranna efterbehandlingssystem för avgaser. När det gäller utsläpp från dieselmotorer utgör NOx-minskning en av de största utmaningarna. För tunga fordon tacklas denna utmaning ofta genom ett SCR-system. SCR-systemet kan omvandla upp till 95% av NOx-utsläppen till kväve och syre, genom utnyttjande av ett selektivt reduktionsmedel över en katalysatoryta. Ammoniak är ett sådant reduktionsmedel men är inte i sig ett lämpligt val för mobila tillämpningar på grund av de miljö-, hälso- och säkerhetsproblem som är förknippade med denna förening. Istället används en ofarlig vattenlösning med urea, kallad AdBlue, som vid injektion i varm avgas sönderdelas till tillräckliga mängder ammoniak som behövs vid SCR-katalysatorn för att minska den NOx som produceras relativt motorns belastningspunkt.  AdBlue-injektion i avgasströmmen kan emellertid komplicera ett redan komplext system ur ett materialvalsperspektiv. Även om urea inte anses vara ett särskilt korrosivt ämne råder en viss osäkerhet kring biprodukterna som kan bildas vid ofullständig nedbrytning av urea. I avgassystem nämns ofta dessa ureaderivat i samband med ett fenomen då smält urea skapar en flytande film på avgassystemets ytor som då genererar fasta biproduktavslagringar vid filmens yttre kanter.  Denna studie syftar till att identifiera några av riskerna kopplade till AdBlue-injektion på ytor av rostfritt stål. Därav undersöks nedbrytningsbeteendet hos de austenitiska rostfria stålen 1.4828 och 1.4835 efter vätning med AdBlue-spray under statiska förhållanden i avgaser, 350 ℃ och 700 kg/h. Testbänksproceduren ger ett kostnadseffektivt sätt att sålla ut potentiella rostfria stål i en realistisk avgasmiljö innan komponenttestning. Testet av 1.4828 inkluderar även ett dragprov, för att undersöka betydelsen av plastiska deformationer. Därtill undersöks en martensitisk stålkomponent, som tidigare använts i en avgasmiljö under AdBlue-injektion, för att ytterligare bilda en uppfattning om de risker som ett material under dessa förhållanden måste uthärda.  Rostfria stål undersöktes efter exponering med konfokalmikroskopi och SEM/EDS. Avlagringar som hittades på 1.4835 studerades med FTIR.  Resultaten visar riskerna med ett dåligt materialval och eventuell frånvaro av oxidfilm som kan relateras till termisk stress, ureanedbrytningsreaktioner med oxidförbrukande egenskaper eller mekaniskt avlägsnande, t.ex. erosion / Emission control, regulated by evermore strict legislation, put high demands on the development of meticulous exhaust gas aftertreatment systems. In diesel engine emissions, NOx reduction poses one of the major challenges. For heavy duty vehicles, this challenge is often tackled by the use of an SCR system, capable of converting up to 95 % of NOx emissions into nitrogen and oxygen, by use of a selective reductant over a catalyst surface. Ammonia is such a reductant but is not in itself an appropriate choice for mobile applications due to the environmental, health and safety concerns associated with this compound. Hence, an aqueous solution of urea, trademarked AdBlue, is used as a harmless reservoir that upon injection into hot exhaust gas decompose into sufficient amounts of ammonia needed at the SCR catalyst to reduce NOx produced, relative to the load point of the engine.  AdBlue injection into the exhaust gas stream can, however, complicate an already complicated system from a material choice perspective. Although, urea is not deemed a particularly corrosive compound, concerns have been raised towards its derivatives often mentioned in relation to a melted urea wall film phenomenon, on exhaust surfaces, generating, solid by-product deposits at the peripheral areas of the film.  This work aims to identify some of the risks coupled with AdBlue injection on stainless steel surfaces. Hence, degradation behaviour of austenitic stainless steel grades 1.4828 and 1.4835, is studied after wetting with AdBlue spray in static exhaust gas conditions, 350 ℃ and 700 kg/h. The test bench procedure, provide a cost-effective way of screening potential stainless steels in a realistic exhaust gas environment before component testing. The test of 1.4828 includes a comparison of the grade with and without plastic deformation. Additionally, a martensitic steel component, used in an exhaust gas environment under AdBlue injection, was added to this work to further portray the risks that a material under these conditions must endure.  Stainless steels are examined post exposure using confocal microscopy and SEM/EDS. Deposits found on 1.4835 were studied with FTIR.  The results portray the risks of a poor material choice and possible absence of oxide film that could be related to thermal stress, decomposition reactions involving oxide consuming properties, or mechanical removal e.g. erosion.

<p>In this thesis deposit and loan rate-setting equations for chartered banks are derived on the premise that these rates are set so as to maximize the banking industry's profits. Because of the oligopolistic nature of the Canadian banking industry and because explicit collusion is illegal an optimizing model of chartered bank ratesetting behaviour was integrated into the institutional framework of the Canadian banking industry.</p> <p>To do this a two-stage model of the Canadian banking industry is proposed. At the first stage, the prime rate on loans and the rate on non-chequing personal savings deposits are set so as to maximize the collective profits of the industry. To circumvent the illegality of explicit collusion a price leadership model is developed. In this model it is not one of the individual banks which is a price leader, but rather changes in the bank rate act as a signal for all of the individual banks to change their rates. The formulation proposed was tested and the hypothesis accepted for both rates. The second stage of the two-stage model is concerned with asset and liability management and is not developed in this thesis.</p> <p>A second contribution of this thesis is to take into account chartered bank rate-setting behaviour when estimating demand equations for both business loans and nonchequing personal savings deposits. When the estimation procedure used reflects these problems it is found that there are large changes in the values of the estimated coefficients in the demand functions for loans and deposits, compared to the simple O.L.S. estimates of the parameter values.</p> / Doctor of Philosophy (PhD)

Following the DWH oil spill event, crude oil reaching the shoreline of Gulf of Mexico produced petroleum oil deposit with a range of distinct geometries, including sphere tar balls and horizontal tar sheets. Numerical models were developed based on the Deep Water Horizon oil spill conditions to evaluate the influence of deposit geometry on long term persistence of residual NAPL oil. Two extreme deposit geometries were modeled in this study: the horizontal tar sheet and the spherical tar ball. Both two-dimensional modeling approach and three-dimensional modeling approach were applied to compare two contrasting geometries. The two-dimensional model results showed that sheet geometry deposits exhibited a greater obstruction to groundwater flow relative to the spherical deposits and induced a larger sulfate reducing zone downgradient of the NAPL source, resulting in significantly greater sulfate-based biodegradation of benzene. Three-dimensional models were constructed to assess the influence of key geometry parameters on oil deposit fate and persistence. Three parameters affecting deposit's geometric structure were recognized, including the upper horizontal area of the sheet deposit, the thickness of the sheet deposit, and the radius of the sphere deposit. The three-dimensional model results suggested that thickness of the sheet deposit and radius of the sphere deposit were important geometry factors impacting the fate and long term persistence of residual NAPL oil in the coastal environment. However, the influence of deposit geometry differed depending on the solubility of the different NAPL components. When high solubility compound and low solubility compound both exist in the oil deposit, the influence of deposit geometry on benzene degradation was significant, while the influence on naphthalene was almost negligible. / Master of Science

The crystalline bedrock of the lowermost Susquehanna River Gorge, Conowingo to Havre de Grace, Maryland, consists of two discrete structural blocks, each with its own unique history prior to juxtaposition. The southern Havre de Grace Block is a Cambrian magmatic arc association (James Run Formation and Port Deposit Intrusive Complex), possibly developed on a rift fragment of Laurentia (Canal Road Formation). The northern Conowingo Block represents a precursory mélange (Conowingo Dam Formation) intruded during the Ordovician by a layered mafic complex (State Line Mafic Complex) and associated plutons (Basin Run Tonalite). Many olistoliths within the Conowingo Dam Formation could have originated in the Havre de Grace Block. The Havre de Grace Block was metamorphosed and deformed under amphibolite facies conditions during Middle Ordovician to Early Silurian time. It was subsequently thrust upon the Conowingo Block along the Elbow Branch Thrust, probably during the Late Ordovician or Early Silurian. From as early as the Middle Devonian, through the Pennsylvanian, dextral strike-slip shearing took place under greenschist facies conditions along the Rock Run Shear Zone, within the northern part of the Havre de Grace Block. Analysis of SC fabrics in the zone yields a minimum offset of 2 to 6 kilometers. From Late Paleozoic to Mesozoic time, strike-slip shearing gave way to dip-slip shearing across very thin, low grade, ductile shear zones. / Master of Science