A non-reactive model system comprising a highly concentrated and unstable oil-in-water emulsion was used to investigate the retention of oil by the membrane in producing biodiesel with a membrane reactor. Critical flux was identified using the relationship between the permeate flux and transmembrane pressure along with the separation efficiency of the membrane. It was shown that separation efficiencies above 99.5% could be obtained at all operating conditions up to the critical flux. It was observed that the concentration of oil in all collected permeate samples using the oil-water system was below 0.2 wt% when operating at a flux below the critical flux. Studies to date have been limited to the characterization of low concentrated emulsions below 15 vol.%. The average oil droplet size in highly concentrated emulsions was measured as 3200 nm employing direct light scattering (DLS) measurement methods. It was observed that the estimated cake layer thickness of 20 to 80 mm was larger than external diameter of the membrane tube i.e. 6 mm based on a large particle size. Settling of the concentrated emulsion permitted the detection of a smaller particle size distribution (30-100 nm) within the larger particles averaging 3200 nm. It was identified that DLS methods could not efficiently give the droplet size distribution of the oil in the emulsion since large particles interfered with the detection of smaller particles. The content of the smaller particles represented 1% of the total weight of oil at 30°C and 5% at 70°C. This was too low to be detected using DLS measurements but was sufficient to affect ultrafiltration. In order to study the critical flux in the presence of transesterification reaction and the effect of cross flow velocity on separation, various oils were transesterified in another membrane reactor providing higher cross flow velocity. higher cross flow velocity provides better separation by reducing materials deposition on the surface of the membrane due to higher shearing. The oils tested were canola, corn, sunflower and unrefined soy oils (Free Fatty Acids (FFA< 1%)), and waste cooking oil (FFA= 9%). The quality of all biodiesel samples was studied in terms of glycerine, mono-glyceride, di-glyceride and tri-glyceride concentrations. The composition of all biodiesel samples were in the range required by ASTM D6751 and EN 14214 standards. A critical flux based on operating pressure in the reactor was reached for waste cooking and pre-treated corn oils. It was identified that the reaction residence time in the reactor was an extremely important design parameter affecting the operating pressure in the reactor. / Natural Sciences and Engineering Research Council of Canada (NSERC)

A non-reactive model system comprising a highly concentrated and unstable oil-in-water emulsion was used to investigate the retention of oil by the membrane in producing biodiesel with a membrane reactor. Critical flux was identified using the relationship between the permeate flux and transmembrane pressure along with the separation efficiency of the membrane. It was shown that separation efficiencies above 99.5% could be obtained at all operating conditions up to the critical flux. It was observed that the concentration of oil in all collected permeate samples using the oil-water system was below 0.2 wt% when operating at a flux below the critical flux. Studies to date have been limited to the characterization of low concentrated emulsions below 15 vol.%. The average oil droplet size in highly concentrated emulsions was measured as 3200 nm employing direct light scattering (DLS) measurement methods. It was observed that the estimated cake layer thickness of 20 to 80 mm was larger than external diameter of the membrane tube i.e. 6 mm based on a large particle size. Settling of the concentrated emulsion permitted the detection of a smaller particle size distribution (30-100 nm) within the larger particles averaging 3200 nm. It was identified that DLS methods could not efficiently give the droplet size distribution of the oil in the emulsion since large particles interfered with the detection of smaller particles. The content of the smaller particles represented 1% of the total weight of oil at 30°C and 5% at 70°C. This was too low to be detected using DLS measurements but was sufficient to affect ultrafiltration. In order to study the critical flux in the presence of transesterification reaction and the effect of cross flow velocity on separation, various oils were transesterified in another membrane reactor providing higher cross flow velocity. higher cross flow velocity provides better separation by reducing materials deposition on the surface of the membrane due to higher shearing. The oils tested were canola, corn, sunflower and unrefined soy oils (Free Fatty Acids (FFA< 1%)), and waste cooking oil (FFA= 9%). The quality of all biodiesel samples was studied in terms of glycerine, mono-glyceride, di-glyceride and tri-glyceride concentrations. The composition of all biodiesel samples were in the range required by ASTM D6751 and EN 14214 standards. A critical flux based on operating pressure in the reactor was reached for waste cooking and pre-treated corn oils. It was identified that the reaction residence time in the reactor was an extremely important design parameter affecting the operating pressure in the reactor. / Natural Sciences and Engineering Research Council of Canada (NSERC)

This thesis provides a general methodology for classifying and describing many combinatoric problems, systematising and finding theoretical expressions for quantities of interest, and investigating their feasible numerical evaluation. Unifying notation and definitions are provided. Our knowledge of random allocations is also extended. This is achieved by investigating new processes, generalising known processes, and by providing a formal structure and innovative techniques for analysing them. The random allocation models described in this thesis can be classified as occupancy urn models, in which we have a sequence of urns and throw balls into them, and investigate static, waiting-time and dynamic processes. Various structures are placed on the relationship(s) between cells, balls, and the selection of items being distributed, including varieties, batch arrivals, taboo sets and blocking sets. Static, waiting-time and dynamic processes are investigated. Both without-replacement and with-replacement sampling types are considered. Emphasis is placed on the distributions of waiting-times for one or more events to occur measured from the time a particular event occurs; this begins as an abstraction and generalisation of a model of departures of cars parked in lanes. One of several additional determinations is the platoon size distribution. Models are analysed using combinatorial analysis and Markov Chains. Global attributes are measured, including maximum waits, maximum room required, moments and the clustering of completions. Various conversion formulae have been devised to reduce calculation times by several orders of magnitude. New and extended applications include Queueing in Lanes, Cake Displays, Coupon Collector's Problem, Sock-Sorting, Matching Dependent Sets (including Genetic Code Attribute Matching and the game SET), the Zig-Zag Problem, Testing for Randomness (including the Cake Display Test, which is a without-replacement test similar to the standard Empty Cell test), Waiting for Luggage at an Airport, Breakdowns in a Network, Learning Theory and Estimating the Number of Skeletons at an Archaeological Dig. Fundamental, reduction and covering theorems provide ways to reduce the number of calculations required. New combinatorial identities are discovered and a well-known one is proved in a combinatorial way for the first time. Some known results are derived from simple cases of the general models. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1309598 / Thesis (Ph.D.) -- University of Adelaide, School of Mathematical Sciences, 2007

Em face ao bom desempenho da agricultura brasileira, cresce tamb&eacute;m a responsabilidade por uma produ&ccedil;&atilde;o sustent&aacute;vel. Particularmente, o sistema produtivo da cana-de-a&ccedil;&uacute;car vem se adaptando a uma produ&ccedil;&atilde;o sem queima, e busca formas alternativas de manejo dos res&iacute;duos da produ&ccedil;&atilde;o que sejam sustent&aacute;veis tanto economicamente, quanto ambientalmente. Neste trabalho apresentamos resultados dos tratamentos de solo agricultur&aacute;vel com res&iacute;duos de i) cinzas de baga&ccedil;o de cana aplicado em cobertura e ii) torta de filtro na entrelinha da cultura, em diferentes doses. Avaliamos o impacto desses tratamentos no conte&uacute;do de carbono e na mat&eacute;ria org&acirc;nica do solo. Para determinar se os tratamentos podem ser considerados sequestradores de carbono e ambientalmente sustent&aacute;veis nos detemos na preserva&ccedil;&atilde;o seletiva como mecanismo de reten&ccedil;&atilde;o da mat&eacute;ria org&acirc;nica do solo, a qual leva a acumula&ccedil;&atilde;o de componentes org&acirc;nicos qu&iacute;micos mais recalcitrantes. Utilizamos as t&eacute;cnicas espectrosc&oacute;picas de fluoresc&ecirc;ncia de luz UV-Vis&iacute;vel, espectroscopia de fluoresc&ecirc;ncia matriz excita&ccedil;&atilde;o-emiss&atilde;o para avaliar a fra&ccedil;&atilde;o de &aacute;cido h&uacute;mico do solo e o aumento da recalcitr&acirc;ncia qu&iacute;mica, a fluoresc&ecirc;ncia induzida por laser (FIL) para observar a mat&eacute;ria org&acirc;nica como um todo e a espectroscopia de emiss&atilde;o &oacute;tica com plasma induzido por laser (LIBS) utilizada como uma nova ferramenta para avaliar o conte&uacute;do de carbono do solo. No tratamento de solo com adi&ccedil;&atilde;o de cinza de baga&ccedil;o de cana tivemos potencial de estoque de carbono na dose 40 t/ha. Quanto a torta de filtro, o carbono total do solo aumenta menos significativamente que na cinza, mas n&atilde;o houve potencial de estoque de carbono. Na fra&ccedil;&atilde;o &aacute;cido h&uacute;mico n&atilde;o observamos modifica&ccedil;&atilde;o do grau de humifica&ccedil;&atilde;o do solo com os tratamentos, mesmo a torta sendo um produto rico em mat&eacute;ria org&acirc;nica, por&eacute;m houve um aumento de grupos carbon&iacute;licos, que est&atilde;o associados ao aumento das intera&ccedil;&otilde;es intermoleculares favorecendo por exemplo a complexa&ccedil;&atilde;o do &aacute;cido h&uacute;mico com metais. Nossos resultados de fluoresc&ecirc;ncia induzida por laser apontam que a cinza possivelmente ofereceu melhora nas condi&ccedil;&otilde;es de crescimento da cultura havendo aumento de grupos alif&aacute;ticos na MOS. Conclu&iacute;mos portanto, que n&atilde;o houve impacto negativo para o estoque de carbono no solo e qualidade da mat&eacute;ria sob tratamento de adi&ccedil;&atilde;o de cinza de baga&ccedil;o de cana e torta de filtro. / Given the good performance of Brazilian agriculture, grows the responsibility for sustainable production. Particularly, the sugarcane production system has been adapting to a production without burning, and seeks alternative forms of waste management in production that are both economically and environmentally sustainable. We present results of arable soil treatments with i) sugarcane bagasse ash applied in coverage soil and ii) filter cake applied between the lines of culture in different doses. We assess the impact of these treatments on the content and quality of soil organic matter and carbon sequestration capacity. To determine if treatments can be considered environmentally sustainable and carbon sequestration we embrace the selective preservation as a retention mechanism of soil organic matter, which leads to accumulation of chemical organic compounds recalcitrant. We use bidimensional fluorescence UV-Visible spectroscopy and fluorescence excitation-emission matrix to assess the fraction of soil humic acid, the laser-induced fluorescence spectroscopy (LIF) for observing the whole organic matter and laser breakdown induced spectroscopy (LIBS) used as a new tool to assess the soil carbon content. The soil treatment with sugarcane bagasse ash had increased carbon stock in dose 40 t / ha. In humic acid fraction did not observe any change in the degree of humification treatment with AML, but there was an increase of carbonyl groups, which are associated with increased intermolecular interactions and enhancing the complexation of metals with humic acid. Our results suggest a possible improvement in crop growth conditions with an increase of aliphatic groups in MOS. The filter cake is no carbon content recorded, also did not observe any impact on soil organic matter with the incorporation of filter cake although this is a product rich in organic matter. In this context, we conclude that there was no negative impact on the carbon stock and quality of soil organic matter under treatment addition of sugarcane bagasse ash and filter cake.

Membrány z dutých vláken jsou široce využívány v aplikacích týkajících se úpravy kapalin jako např. při čištění odpadních vod, v membránových kontaktorech a bioreaktorech, membránové destilaci apod. I když jsou často využívány při separacích směsí plynů, je jejich použití pro mechanickou filtraci aerosolů velmi vzácné. Tato práce se zabývá filtrací vzduchu pomocí polypropylenových membrán z dutých vláken včetně jejich filtrační účinnosti, tlakových ztrát a také zanášením při dlouhodobé filtraci. Filtrační účinnost byla proměřena za použití různých aerosolů jako TiO2 a síran amonný. Tlakové ztráty byly měřeny při různých konfiguracích, tj. různé filtrační ploše a průměru vlákna membrány. Zanášení membrán bylo testováno použitím normovaného prachu definovaného normou ANSI/ASHRAE 52.2. Predikční modely pro filtrační účinnost a permeabilitu/tlakovou ztrátu membrány byly aplikovány na parametry membrán z dutých vláken a porovnány. Tyto membrány mají velikost pórů kolem 90 nm a poměrně nízkou porositu a tím vysoký potenciál pro separaci nanočástic ze vzduchu. Dále byla provedena analýza filtračního koláče a vyhodnocení energetických nároků a porovnány s teoretickými modely. V závěru práce je nastíněn odhad ceny životního cyklu při filtraci pomocí těchto membrán.

Tato diplomová práce se zabývá netradičními druhy biomasy využitelnými v České republice a Španělsku a jejich srovnáním. V prvních kapitolách jsou popsány netradiční druhy biomasy, mezinárodní projekty, smlouvy a legislativa. V následujích kapitolách je rozbor netradičních druhů biomasy zejména vznikajících z potravinářského průmyslu každé země s detailním rozborem a srovnáním zbytků z průmyslového zpracování slunečnice a oliv. V závěru je uděláno celkové srovnání těchto druhů biomasy České republiky a Španělska z aspektů výkupních cen, výhřevností, vlhkosti a množství popelovin.

A non-reactive model system comprising a highly concentrated and unstable oil-in-water emulsion was used to investigate the retention of oil by the membrane in producing biodiesel with a membrane reactor. Critical flux was identified using the relationship between the permeate flux and transmembrane pressure along with the separation efficiency of the membrane. It was shown that separation efficiencies above 99.5% could be obtained at all operating conditions up to the critical flux. It was observed that the concentration of oil in all collected permeate samples using the oil-water system was below 0.2 wt% when operating at a flux below the critical flux. Studies to date have been limited to the characterization of low concentrated emulsions below 15 vol.%. The average oil droplet size in highly concentrated emulsions was measured as 3200 nm employing direct light scattering (DLS) measurement methods. It was observed that the estimated cake layer thickness of 20 to 80 mm was larger than external diameter of the membrane tube i.e. 6 mm based on a large particle size. Settling of the concentrated emulsion permitted the detection of a smaller particle size distribution (30-100 nm) within the larger particles averaging 3200 nm. It was identified that DLS methods could not efficiently give the droplet size distribution of the oil in the emulsion since large particles interfered with the detection of smaller particles. The content of the smaller particles represented 1% of the total weight of oil at 30°C and 5% at 70°C. This was too low to be detected using DLS measurements but was sufficient to affect ultrafiltration. In order to study the critical flux in the presence of transesterification reaction and the effect of cross flow velocity on separation, various oils were transesterified in another membrane reactor providing higher cross flow velocity. higher cross flow velocity provides better separation by reducing materials deposition on the surface of the membrane due to higher shearing. The oils tested were canola, corn, sunflower and unrefined soy oils (Free Fatty Acids (FFA< 1%)), and waste cooking oil (FFA= 9%). The quality of all biodiesel samples was studied in terms of glycerine, mono-glyceride, di-glyceride and tri-glyceride concentrations. The composition of all biodiesel samples were in the range required by ASTM D6751 and EN 14214 standards. A critical flux based on operating pressure in the reactor was reached for waste cooking and pre-treated corn oils. It was identified that the reaction residence time in the reactor was an extremely important design parameter affecting the operating pressure in the reactor. / Natural Sciences and Engineering Research Council of Canada (NSERC)

Planetens resurser utnyttjas inte på ett ansvarsfullt sätt och för att uppnå en hållbar utveckling behöver en förändring ske i hur dessa resurser konsumeras och produceras. Ett företag som arbetar för att använda sina resurser mer effektivt och minska sin negativa miljöpåverkan är Aurobay Sweden AB.  Aurobay tillverkar drivlinor för interna hybrid- och förbränningsmotorer och använder skärande bearbetning i delar av sin produktionsprocess. Till den skärande bearbetningen används skärvätska vilket behöver filtreras för att kunna återanvändas. Företaget använder en filtreringsprocess med filterduk för att separera spånor från skärvätskan. Aurobay vill minska sin förbrukning av filterduk och skaffa en bättre förståelse för hur företagets filtreringsutrustning kan nyttjas bättre i framtiden.  Ett experiment genomfördes för att utvärdera hur en förändring av cykeltid påverkade mängden spånor som transporterades bort från filtreringsutrustningen. Resultatet visade att mätningar behöver genomföras under en längre period eftersom externa faktorer kan ha en påverkande effekt. Efter en nulägesanalys av utnyttjandegraden på några av företagets filtreringsutrustningar kunde det konstateras att den kunde vara så låg som 15 %. Genom att öka cykeltiden som filtreringsutrustningarna filtrerar kan utnyttjandegraden höjas och förbrukningen av filterduk minskas med 26 %. Utan ytterligare investeringar kan Aurobay minska kostnaderna för att köpa in ny filterduk och hantering av den förbrukade. / The planet’s resources are not being utilized responsibly, and to achieve sustainable development, changes are needed in how these resources are consumed and produced. Aurobay Sweden AB is one such company working to use its resources more efficiently and reduce its negative environmental impact.  Aurobay manufactures drivetrains for internal hybrid and combustion engines and for some of its production process machining is used. Cutting fluid is used in this machining process and it needs to be filtered before reuse. Aurobay utilizes a filtration process with filter media to separate chips from the cutting fluid. Aurobay aims to reduce its use of filter media and seeks to gain a better understanding of how the company’s filtration equipment can be optimized for future use.  An experiment was conducted to assess the impact of changing the filtration equipment’s cycle time when it comes to remove chips from a filtration process. The results indicated that measurements need to be conducted over a longer period as external factors may have an influencing effect. After an analysis of the utilization rate on some of the company’s filtration process equipment, it was found that utilization rates could be as low as 15 %. The utilization rate can be improved by increasing the cycle time which the filtration equipment operates, and the consumption of filter media can be reduced by 26 %. Without additional investments, Aurobay can reduce the costs for both purchasing new filter media and removal of the old one.