anglický Phlebotomine sand flies (Diptera: Psychodidae) are the only proven vectors of Leishmania parasites (Kinetoplastida: Trypanosomatidae). In Nematoceran Diptera, including sand flies, adults produce a type 1 peritrophic matrix (PM) which is secreted in response to the distension of the midgut caused by blood meal. The PM is an acellular envelope composed of chitin fibres and proteins, which protects the midgut epithelium against abrasion and pathogens and improves digestion. In hematophagous insects, the PM also plays a central role in heme detoxification. Female sand flies acquire Leishmania with a bloodmeal and the parasites undergo complicated development in their gut finished by the colonization of the stomodeal valve. The PM is one of the most important barriers in Leishmania development and its role in the vector competence of the S. schwetzi is the main topic of this master thesis. The PM's kinetic and morfology in the S. schwetzi is compared with other three sand fly species which differ in susceptibility to L. donovani. The key role of the PM in S. schwetzi vector competence is finally proved by disrupting the PM using the exogenous chitinase from Beauveria bassiana. Under these artificial conditions, the Leishmania parasites (L. donovani and L. major) are able to exit the PM,...

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15338号 / 工博第3217号 / 新制||工||1484(附属図書館) / 27816 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 石田 毅, 教授 松岡 俊文, 教授 三ケ田 均 / 学位規則第4条第1項該当

Abstract The objective of this thesis was to determine the effects of design, operational and furnish quality parameters on pressure screen and hydrocyclone performance. The general contradictory interrelationships between capacity and selectivity in pressure screening and cleaning are commonly recognized, but deep understanding of the effects of design, operational and furnish quality parameters on the state of operation is missing. As separation selectivity is closely dependent on thickening and pulp passage, an operation curve for separation was applied and its application further developed to examine the parameters affecting pressure screen and hydrocyclone separation. New information was found on the geometry of the screen plate, furnish quality parameters in pressure screen fibre fractionation, and the hydrocyclone separation of fibres, sand and gases. The capacity increases achieved by changes in the wire screen plate geometry were found to be achieved at the cost of separation selectivity in probability screening. The capacity of the screen plate was affected by the flow on the screen plate and through it. The hydraulic resistance both in the forward and reverse flow directions was found to be of great importance for the capacity of the screen plate. Previously unreported knowledge was found regarding the effects of wire width, height and shape. Pressure screening capacity was found to decrease with increasing fibre length, fibre network strength and flocculation. Pressure screen fibre fractionation selectivity was increased by broadening of the fibre length distribution of the feed furnish. The furnish properties also affected the separation selectivity of fibres, sand and gases in the hydrocyclone. An increase in fibre network strength reduced the separation selectivity of the hydrocyclone separation of fibres and sand. Any increase in the specific surface area, and especially in the amount of fines, was found to make gas removal more challenging. It was concluded that a broader range of the specific surface distribution can increase the selectivity of fibre fractionation in the hydrocyclone. Knowledge of the general effects of design, operational and furnish quality parameters on the performance of pressure screen and hydrocyclone separation was deepened as a result of this work, which provides a framework for studying these effects further in pursuit of the general objective of maximizing capacity and selectivity while minimizing energy and investment costs.

[pt] No litoral brasileiro, do Rio Grande do Norte até Rio de Janeiro, se encontram os mais importantes depósitos de areias monazíticas No litoral do Município de São Francisco de Itabapoana, no estado de Rio de Janeiro, encontram-se importantes jazidas de areias monazíticas, e na vila de Buena, situada neste município, se encontra uma usina de beneficiamento de areias monazíticas. Nela são obtidos concentrados de ilmenita, zirconita, rutilo e monazita utilizando separadores letrostáticos, eletromagnéticos e gravimétricos (espirais, planos inclinados e mesas vivratorias). Com o objetivo de caracterizar a exposição dos habitantes desta vila a partículas de poeira na fração respirável foram coletadas amostras de aerossóis usando impactadores em cascata, amostradores portáteis com ciclone e amostras de bioindicadores. As amostras foram analisadas pelo método PIXE (Particle Induced X ray Emission) para determinação da concentração dos metais e do MMAD (Mass Median Aerodinamic Diameter), por PDMS (Plasma Desorption Mass Spectrometry) para identificação dos compostos presentes. As amostras de aerossóis coletadas com amostradores portáteis e de bioindicadores foram analisadas para determinação da concentração dos isótopos das séries naturais do tório e urânio. Os resultados indicam que os habitantes estão expostos a partículas contendo metais na fração respirável do aerossol geradas por fontes tanto antropogênicas , quanto naturais. As amostras de bioindicadores indicam os habitantes da vila tem estado expostos a radionuclídeos das séries naturais do tório e urânio nos últimos 15 anos. / [en] The main deposit of mineral sands in Brasil occur from the Rio Grande do Norte State to Rio de Janeiro State. The main commercial deposit is located in Buena, a village at São Francisco de Itabapoana, Rio de Janeiro State. In buena there is a plant that process minerals sands to obtain ilmenite, zirconite, rutile and monazite concentrates. This plant belongs to the Industrias Nucleares Brasileiras (INB). Close to this plant there is a small village. Aerosols samples were collected using cascade impactors and cyclones in order to characterize human exposure to airborne particles in the respirable fraction. Lichens samples were also collected. The samples were analyzed by PIXE (Particle Induced X ray Emission) for determination of elemental mass concentration and MMAD (Mass Median Aerodynamic Diameter). PDMS (Plasma Desorption Mass Spectrometry) allows the identification of the chemicals compounds present in the samples. The concentrations of radionuclides from the thorium and uranium natural series were also determined. The results show that the inhabitants were espoused to airborne particles in the respirable fraction of aerosols from natural and anthropogenic sources. The lichens samples indicate that the inhabitants have been exposed to radionuclides from the thorium and uranium natural series since last 15 years.

The availability to clean drinking water is something a lot of people take for granted today. Daily, there are about 1.8 billion people around the world that drinks water from a contaminated water source. Unfortunately, the deficiency is a fact, and about 361 000 children under the age of five die each year because of diarrheal disease (WHO, 2016a).  Earlier studies show that a biosand filter is an easy and efficient water purification method that cleans the water both physically, biologically and chemically. A biosand filter is often built using local material and is filled with sand, which makes the construction cheap and easy to repair is needed. Earlier studies have shown that this purification method can reduce waterborne disease by 99,9% with the help of a biofilm layer which develop in the top layer of the sand if the conditions are meet (CAWST, 2009). The purpose with this study was to build and evaluate a biosand filter as a water treatment method in Ghana. In total, three biosand filters was built with local material, each with different sand heights. The evaluation was done by studying the waters physical, biological and chemical properties before and after the filtration, which then was compared to the water quality standards from the World Health Organization (WHO) and Sweden. The results show that none of the three filters could produce water which met the standards for drinking water, which might be caused by the high flow of water through the filter which prevented the biofilm to grow. With the help from the results in Ghana, a new design of a water filter has been made to reduce the flow of water through the filter. Which gave a new biosand filter design with a diameter of 42 cm that, sand height of 80 cm and gravel height of 15 cm. / Tillgången till rent dricksvatten är idag något som många tar som en självklarhet. I dagsläget är det omkring 1.8 miljarder människor i världen som dagligen dricker vatten från en kontaminerad vattenkälla. Dessvärre är bristen på rent dricksvatten ett faktum, vilket gör att det årligen dör cirka 361 000 barn under fem års ålder på grund av diarrésjukdomar världen över (WHO, 2016a).  Tidigare studier har visat på att biosandfilter är en enkel och effektiv vattenreningsmetod för att rena vatten både fysiskt, biologiskt och kemiskt. Ett biosandfilter är ofta byggt med lokala material och fylld med sand, vilket gör konstruktionen billig och enkel att reparera vid behov. Tidigare studier har visat på att vattenreningsmetoden kan reducera vattenburna sjukdomar med upp till 99.9% med hjälp av ett biofilmslager som utvecklas i sandlagrets övre skikt om förhållandena är gynnsamma (CAWST, 2009).  Syftet med denna studie var att bygga och utvärdera biosandfilter som vattenreningsmetod i Ghana. Totalt byggdes tre biosandfilter av lokala material med olika sandhöjder. Utvärderingen gjordes utifrån att studera vattnets fysiska, kemiska och biologiska egenskaper före och efter filtrationen, som sedan jämfördes med vattenkvalitetsstandarder från World Health Organization (WHO) och Sverige. Resultaten visade på att ingen av de tre sandfiltret kunde producera vatten med en drickvattenstandard, detta tros bero på det höga flödet genom filtret som hindrat biofilmstillväxten. Med hjälp av resultat från Ghana har en ny design av ett biosandfilter tagits fram för att minska flödet genom filtret. Vilket gav en filterdiameter som är ungefär 42 cm som sedan är fylld med 80 cm sand och 15 cm grus.

In 2015, the United nations presented the 17 Global Goals that would put an end to extreme poverty, inequality and climate change by 2030. One of these goals was clean water and sanitation. In 2015 1.8 billion people did not have access to clean water. Because of the contaminated water, one million people die every year worldwide. Africa, and especially Ghana, has had a high development in the recent years. The population has grown and more resources are needed. Clean water in Ghana is not a given matter, three million people live without access to clean water. To work towards the Global Goal water can be clean locally. A simple and cheap way is to build slow sand filters, which also are the purpose of this project. These filters purify the water mechanically, chemically and biologically. The biologically purification takes place in the biolayer that grows on the sand inside the filter and it consumes contaminants in the water. It takes about a month for the biolayer to be fully developed and clean the water to its full potential. The positive aspects with sand filters are that people get healthier and can save money that can be invested in education or business. It can also reduce the need for water in plastic bags or bottles and would reduce littering. The companies that produce this water could end their business and air pollutions would be reduced as well.   During this project, slow sand filters have been tested and evaluated in Sweden and Ghana with the purpose to develop a theoretical filter that benefits the biolayer under local conditions in Ghana, this was of the one aims. Experiments in Sweden showed that the flow decreased with increased sand height and decreased hydraulic head. In Ghana three filters were built with the sand heights 30, 50 and 80 cm to clean 7 litres of drinking water for a family of four. None of these produced drinkable water by WHO’s and EU’s standards.   The next aim was to understand which chemical and physical factors that effected the development of the biolayer. The detected relations were absolute conductivity, total alkalinity, coliform bacteria and oxidantial reduction potential which were between the biolayer in the 30 and 50 filters.   The flow rate in Ghana was too high and to lower it, a new diffuser with smaller holes would be built to get the recommended flow of 0,4 m3/m2/h. A too high flow broke the bound between the biolayer and made an uncomfortable environment. A sedimentation should be installed before the sand filter to reduce the variations of the incoming water such as turbidity, suspended solids etc., so the biolayer would flourish. It was not enough dissolved oxygen in the water so the pause period would be decreased to 12 hours to get more oxygen in the filter each day. For a sand filter to work as planned a lot of attention should be given to the filter. It is a system that should be used all the time for the best purification. To build a filter takes a lot of time and it also takes time for the biolayer to develop. If it is not going to be used much, another treatment method should be used.   The last aim was to evaluate the cost of the materials that could be bought locally to the filter. One filter cost about 130 GHS. / 2015 tog Förenta nationerna fram de 17 globala målen för att få ett slut på extrem fattigdom, ojämlikhet och klimatförändringen till år 2030. Ett av dessa mål handlar om rent vatten och sanitet. 2015 var det 1,8 miljarder människor som inte hade tillgång till rent vatten. På grund av det förorenade vattnet dör en miljon människor i hela världen varje år. Afrika, och speciellt Ghana, har haft en snabb utveckling de senaste åren. Folkmängden har ökat och mer naturresurser behövs. Rent vatten i Ghana är inte en självklarhet, tre miljoner människor lever idag utan tillgång till rent vatten i Ghana. Ett sätt för att jobba mot det globala målet är rening av vatten lokalt. Ett enkelt och billigt sätt är att bygga långsamsandfilter, vilket även var syftet med denna studien. Dessa filter renar vattnet mekaniskt, kemiskt och biologiskt. Den biologiska reningen sker av en biofilm som växer på sanden inuti filtret som konsumerar föroreningar i vattnet. Det tar ungefär en månad för biofilmen att bli färdigutvecklad och rena vattnet till sin fulla potential. Det positiva med sandfilter är att människorna skulle bli friskare och spara pengar som kan investeras på utbildning eller företag. Ur miljöpunkt skulle reduktionen av köpt vatten i plastpåsar och flaskor minska nedskräpningen och företagen som producerar dessa kan avsluta produktionen och därmed minska luftföroreningar.    Under detta projekt har långsamsandfilter utvärderats både i Sverige och Ghana för att utveckla ett nytt teoretiskt filter som gynnar tillväxten av biofilm under lokala förhållanden i Ghana, vilket var ett mål. Experimenten i Sverige visade att flödet sjönk med ökad sandhöjd, men även med minskat hydrauliskt tryck. I Ghana byggdes tre filter med sand höjderna 30, 50 och 80 cm för att rena 7 liter dricksvatten till en familj på fyra. Ingen av dessa lyckades producera drickbart vatten enligt WHO:s och EU:s standarder.   Nästa mål var att förstå vilka av de kemiska och fysiska faktorer som påverkade biofilmstillväxten. Det förhållanden som upptäcktes var absolut konduktivitet, total alkalinitet, coliform bacteria och oxidential reduction potential vilket fanns i 30 och 50 filtret.   Flödet i Ghana var för högt, så för att minska det skulle en diffusör med mindre hål byggas för att få det rekommenderade flödet 0,4 m3/m2/h. Ett för högt flöde gjorde sönder bindingen mellan biofilmen och skapade en otrivsam miljö. En sedimentation skulle installeras innan sandfiltret för att minska variationer på ingående vatten i filtret för att få biofilmen att trivas bättre. Det fanns för lite löst syre i vattnet och om pausperioden minskas till 12 timmar skulle mer syre i filtret varje dag. För att ett sandfilter ska fungera som planerat måste mycket tid läggas på filtret. Sandfilter är ett system som bör används ofta för bästa rening. Att bygga ett filter kräver mycket tid, samt att det tar tid innan biofilmen har utvecklats. Om sandfiltret inte kommer används mycket föreslås att en annan metod används istället.   Det sista målet var att utvärdera kostnaden av materialen som kunde köpas lokalt till filtret. Ett filter kostade runt 130 GHS.

Les travaux de recherche entrepris dans le cadre de cette thèse sont destinés à permettre de démontrer que dans la technique de projection, le béton de sable fibré peut remplacer le béton ordinaire habituellement utilisé.La technique de projection du béton est notamment utilisée dans les travaux de soutènement et de tunnels, la stabilisation des pentes mais aussi dans la conception des panneaux 3D.Le béton utilisé, à ce jour, dans la technique du béton projeté dans la conception des panneaux 3D est à base de gravillons 3/8 mm. Cependant, l'inconvénient avec ce mélange, c'est les pertes par rebond du matériau et de fibres qui sont importantes (jusqu'à 50%), d'où un impact économique défavorable et une influence négative sur les propriétés mécaniques du matériau en place sur le support.Le béton de sable composé d'un faible dosage en ciment, sable et une grande quantité de fines calcaires semble tout à fait indiqué pour pallier ce problème, étant donné les avantages que procurent ses finesse, cohésion, fluidité et homogénéité. Dans le cadre de cette étude, les performances du béton de sable projeté (BSP) ont été comparées à celles du béton ordinaire projeté (BOP). Pour le retrait, le comportement a aussi été confronté à celui du béton vibré. Les paramètres de comparaison ont concerné l'état frais (avant, pendant et après projection) et l'état durci, avec une attention particulière portée aux taux de rebond des matériaux, aux résistances mécaniques et aux retraits (endogène et de dessiccation).Les résultats de nos investigations ont mis en évidence un certain nombre d'avantages du BSP par rapport au BOP. A cet effet, notons la réduction des pertes par ricochet des matériaux (béton et fibres) de moitié, avec des épaisseurs de couches de béton projeté de 9 cm contre 6 cm pour le BOP. L'autre point positif, c'est la qualité du fini de surface. Du point de vue de la résistance à la compression, le BSP présente une amplitude plus importante au jeune âge, mais équivalente à long terme. Le retrait endogène du BSP est similaire à ceux des BOP et des bétons vibrés (BV), aussi bien en amplitude qu'en cinétique. Quant au retrait de dessiccation, le BSP manifeste une déformation de l'ordre de 10% plus élevée que celle du BOP. Alors que par rapport au BV, la magnitude de la déformation du BSP est plus petite que celle du BV, et ce en dépit d'une perte d'eau par évaporation plus importante. Par conséquent, et en opposition à la majorité des résultats de la littérature, un perte de poids plus importante par dessiccation, n'implique pas systématiquement une déformation de retrait plus importante. L'autre résultat inattendu est que la structure monomodale de type « méso » du BSP est affectée par une cinétique de séchage plus rapide que la structure bimodale de type « macro » et « méso » du BV.Par ailleurs, l'ajout de 50 kg/m3 de fibres métalliques au BSP réduit le retrait de dessiccation de 16 %, alors que leur influence semble ne jouer aucun effet sur la cinétique ou la magnitude de la déformation du BOP, du moins dans les proportions du dosage utilisé.La proportion de mésopores semble un facteur décisif dans le comportement des retraits de dessiccation des bétons. Dans ce contexte, une explication est fournie pour mettre en relief les raisons du retrait moins important du BSP par rapport au BV, malgré une perte d'eau par séchage plus importante et un volume de pâte plus important. / This paper presents test results of mechanical properties of fibre reinforced sand-concrete (BSP) formulated to be used in the sprayed wet-mix process, as a substitution to fibre reinforced concrete (BOP) sprayed by dry-mix process. This process of application of concrete is suitable for diverse applications such underground support and slope stabilization. In BOP, formulated with aggregates up to 8 mm, both material and fibre rebounds are high (50 %); this results in economic implications, and affects the performances of the mixture negatively.BSP formulated with low dosage of cement, sand and high content of limestone filler, but without coarse aggregate; seems to be indicated to alleviate most of these problems, because of its fineness, high cohesiveness, high fluidity and better homogeneity. BSP was investigated and compared with BOP, on the basis of fresh and hardened properties with special emphasis on rebound, compressive strength and drying shrinkage. Results of investigations showed many advantages of this new mixture (BSP) when compared to BOP: reduction of material and fibre rebounds by approximately 50%, relatively substantially thicker layers (9 cm vs 6 cm), good finishing surface, higher early age compressive strength, and long term drying shrinkage close to that of BOP.Comparison of the results shows that the endogenous shrinkage of BOP, BSP and vibrated concrete (BV) is similar.On the other hand, the present study showed that a low amount of steel fibre (50 Kg/m3)reduces the drying shrinkage of BSP by approximately 16%.While, in the case of BOP, the influence is not significant.The aim of this study is to bring some answers to the questions about the delayed deformation of the shooting sand-concrete [BSP], which is made of aggregates up 5 mm.Drying shrinkage results, revealed that drying shrinkage of BSP is higher than that of BV in the short term. In the long term, it becomes lower than that of BV. However, the BSP loses more water during the period of shrinkage measurements than BV. Furthermore, pore size distribution shows that the mesoporous structure of BSP lost more water than the bimodal structure of BV, which includes macropores and mesopores. These particular porometric structures of BSP and BV are the main factor behind the difference of the drying shrinkage behaviour of the two mixtures.This is an interesting and unexpected result, which is not in accordance with the commonly accepted relationship between shrinkage and weight change of samples, and between moisture loss and porometric structure. This work provides an explanation for this phenomenon by taking into account the kinetics of drying and the porometry of the concrete.

L'injection de vapeur lors de la production des bruts lourds par SAGD soumet les roches réservoirs (sables bitumineux non consolidés ou faiblement consolidés) à une élévation de température (jusqu'à 280°C). L'apport de fluide chaud augmente la pression de pore, dilate le squelette rocheux et le fluide interstitiel, ce qui modifie le champ de contrainte in situ. Le travail de thèse, à forte connotation expérimentale, vise à contribuer à la caractérisation mécanique et acoustique des réservoirs bitumineux sous différentes conditions de température, de contrainte et de saturation. Les travaux ont été effectués sur des échantillons de sables bitumineux Canadiens, mais également sur un matériau modèle, un sable reconstitué artificiellement cimenté. Plusieurs techniques expérimentales ont été mises en œuvre pour caractériser les matériaux utilisés : tomographie RX, microtomographie RX, cryomicroscopie, RMN, etc. Des essais ont ensuite été effectués dans une cellule oedométrique, une cellule pétroacoustique et également dans une cellule triaxiale dite haute température qui a été développée dans le cadre de cette thèse.Les divers essais de chargement mécanique et thermique dans cette thèse ont permis d'enrichir les connaissances sur le comportement thermo-hydro-mécanique des sables bitumineux ainsi que celui des sables reconstitués. Les paramètres investigués ont été la dilatation thermique, la compressibilité sous chargement oedométrique et triaxial isotrope et la résistance au cisaillement. Les différentes mesures des propriétés acoustiques (vitesses Vp et Vs, atténuations et modules dynamiques) effectués sur les sables naturels et reconstitués ont montré l'importance des propriétés des fluides saturants, principalement de leur viscosité. Le bitume est un fluide viscoélastique avec une viscosité qui varie avec l'élévation de la température. Aux températures in situ, il se comporte comme un solide avec un module de cisaillement. L'approche théorique de Ciz et Shapiro (2007), permet de prendre en compte ce module de cisaillement du fluide visqueux et généralise l'équation de Biot Gassmann. Son utilisation a été validée sur nos essais. La modélisation prend en compte les aspect dispersifs et permet d'extrapoler aux fréquences sismiques des résultats acquis en laboratoire avec des fréquences ultrasonores. Les vitesses Vp et Vs diminuent avec le passage de la chambre de vapeur. Les variations sont faibles mais peuvent être identifiées par la sismique 4D / The steam assisted gravity drainage (SAGD) has been successfully used to enhance the recovery of heavy oil in Western Canada and Eastern Venezuela basins. Temperature, pressure and pore fluid variations during SAGD operations induce complex changes in the. properties of the heavy oil sand reservoir. This dissertation focuses on the geomechanical and acoustic behaviours of oil sand and how they change under various temperature, pressure and pore fluid conditions. Both natural oil sands samples and reconstituted samples were tested in this research program. Several experimental techniques have been used to characterize the materials including X-Ray tomography, X-ray microtomography, cryomicroscopy, NMR. Natural oil sands samples, characterized by high permeability, high porosity and an interlocked structure have been extracted from the estuarine McMurray Formation in Athabasca (Alberta, Canada). Reconstituted samples, made up of slightly cemented Fontainebleau sand, have been considered as possible analogues of the natural oil sands. Tests have been carried out in high pressure oedometer cells, in an isotropic pressure cell and in a new high temperature triaxial cell. The various geomechanical and thermal tests have been carried out to better understand the thermo-hydro-mechanical behaviour of natural oil sands and of reconstituted samples. The parameters investigated were the thermal dilatation, the bulk compressibility (under oedometric and isotropic loading) and the shear strength. The acoustic measurements (P and S-wave velocities, attenuations and dynamic modules, etc.) performed on natural oil sands and reconstituted samples showed the importance of the saturating fluids properties, mainly through viscosity. Bitumen has a viscoelastic behaviour with a non-negligible shear modulus that depends strongly on temperature and frequency and that allows shear wave propagation. The theoretical approach of Ciz and Shapiro (2007), that accounts for the effects of the shear modulus of the viscous fluid and generalizes the Biot – Gassmann equation, has been validated by our tests. The model takes into account the dispersive aspects and allows the results obtained in the laboratory with ultrasonic frequencies to be extrapolated to seismic frequencies. Velocities Vp and Vs decrease with the steam invasion. Changes are small but can be detected by 4D seismic

This research is about the development of a photocatalytic reactor design, Honeycomb, for in-situ groundwater remediation. Photocatalysis, typically a pseudo first order advanced oxidation process, is initiated via the illumination of UVA light on the catalyst, i.e. titanium dioxide (TiO2). In the presence of oxygen, highly reactive oxidising agents are generated such as superoxide (O2-), hydroxyl (OH.-) radicals, and holes (hvb+) on the catalyst surface which can oxidise a wide range of organic compounds. The target contaminant is methyl tert butyl ether (MTBE), a popular gasoline additive in the past three decades, which gives the water an unpleasant taste and odour at 20 μg L-1, making it undrinkable. This research consists of three major parts, i.e. (i) establishing a suitable catalyst immobilisation procedure, (ii) characterisation and evaluation of reactor models and (iii) scale up studies in a sand tank. TiO2 does not attach well onto many surfaces. Therefore, the first step was to determine a suitable immobilisation procedure by preparing TiO2 films using several potential procedures and testing them under the same conditions, at small scale. The coatings were evaluated in terms of photocatalytic activity and adhesion. The photocatalytic activity of the coatings was tested using methylene blue dye (MB), which is a photocatalytic indicator. A hybrid coating, which comprises a sol gel solution enriched with Aeroxide TiO2 P25 powder, on woven fibreglass exhibited the best adhesion and photocatalytic activity among samples evaluated. Thus, it was used to produce immobilised catalyst for this research. Consequently, the immobilisation procedure was scaled up to synthesize TiO2 coatings for the potential photocatalytic reactor design. The photocatalytic activity of the coatings produced from the scaled up immobilisation procedure were reasonably comparable to that produced at small scale. Due to the UVA irradiation and mass transfer limitations, photocatalytic reactors are typically compact in order to maximise their efficiency to accommodate high flows, particularly in water and wastewater treatment. In the case of groundwater, however, the treatment area can span up to meters in width and depth. Groundwater flow is significantly lower than that of water treatment, as the reactor design does not need to be compact. Considering both factors, a photocatalytic reactor design of hexagonal cross-section (Honeycomb) was proposed, in which the structures can be arranged adjacent to each other forming a honeycomb. A model was constructed and tested in a 4 L column (cylindrical) reactor, using the MB test to characterise the reactor performance and operating conditions. This was followed by a hydraulic performance study, which encompasses single and double pass flow studies. The single pass flow study involves the photocatalytic oxidation (PCO) of MB and MTBE, while the double pass flow study was focused on the PCO of MTBE only. The double pass can simulate two serially connected reactors. Single pass flow studies found that the critical hydraulic residence time (HRT) for the PCO of MB and MTBE is approximately 1 day, achieving up to 84 % MTBE removal. Critical HRT refers to the minimum average duration for a batch of contaminant remaining in the reactor in order to maintain the potential efficiency of the reactor. Double pass studies showed the reactor can achieve up to 95 % MTBE removal in 48 hours, and that reactor performance in the field of serially connected reactors can be estimated by sequential order of single pass removal efficiency. In groundwater, there are likely to be other impurities present and the effects of groundwater constituents on the reactor efficiency were studied. The MTBE PCO rate is affected by the presence of organic compounds and dissolved ions mainly due to the competition for hydroxyl radicals and the deactivation of catalyst surface via adsorption of the more strongly adsorbed organic molecules and ions. Despite the presence of organic compounds and dissolved ions, the reactor achieved about 80 % MTBE removal in 48 hours. A double pass flow study showed that the overall efficiency of the photocatalytic reactor in the field can be estimated via sequential order of its efficiency in a single pass flow study using the actual groundwater sample in the laboratory. A sand tank was designed for the simulation of the clean up of an MTBE plume from a point source leakage using the 200 mm i.d. Honeycomb I prototype. Honeycomb I achieved up to 88.1 % MTBE removal when the contaminated groundwater flowed through (single pass) at 14.6 cm d-1. The critical HRT for Honeycomb I was also approximately 1 day, similar to that in the column reactor. The response of MTBE removal efficiency towards flow obtained in the column reactor and sand tank was generic, indicating that the reactor efficiency can be obtained via testing of the model in the column reactor. The presence of toluene, ethylbenzene and o-xylene (TEo-X) decreased the MTBE removal efficiency in both the sand tank and column reactor. The same set of catalyst and 15 W Philips Cleo UVA fluorescent lamp was operated for a total of about 582 h (24 d) out of the cumulative 1039 h (43 d) sand tank experiments, achieving an overall MTBE removal efficiency of about 76.2 %. The experiments in the column reactor and sand tank exhibited the reliability of the immobilised catalyst produced in this research. This research demonstrates the potential of Honeycomb for in-situ groundwater remediation and also proposes its fabrication and installation options in the field.

Shallow foundations can provide the most economical solution for supporting small-scale structures. The design approach is quite simple considering the ultimate bearing capacity and working-load settlement. Research has shown that settlement calculations, determined using a linear-elastic approach, usually govern the design but this approach is inappropriate because soil is highly non-linear, even at small strains. The result is that signifi cant discrepancies are observed between predicted and actual settlements. This uncertainty has seen the development of settlement-based approaches such as Mobilisable Strength Design (MSD). MSD uses an assumed undrained mechanism and accounts for soil non-linearity by scaling a triaxial stress-strain curve to make direct predictions of footing load-settlement behaviour. Centrifuge experiments were conducted to investigate the mechanisms governing the settlement of shallow circular foundations on clay and saturated sand models. Clay model tests were performed on soft or rm kaolin beds, depending on its pre-consolidation. Sand model tests were performed on relatively loose Hostun sand saturated with methyl-cellulose to slow consolidation. One-dimensional actuators were developed to apply footing loads through dead-weight or pneumatic loading. A Perspex window in the centrifuge package allowed digital images to be captured of a central cross-section, during and after footing loading. These were used to deduce soil displacements by Particle Image Velocimetry which were consistent with footing settlements measured directly. Deformation mechanisms are presented for undrained penetration, consolidation due to transient flow, as measured by pore pressure transducers, and creep. A technique was developed for discriminating consolidation settlements from the varying rates of short and long-term creep of clay models. Using MSD, a method for predicting the undrained penetration of a spread foundation on clay was proposed, using database results alone, which then provided estimates of creep and consolidation settlements that follow. The importance of the undrained penetration necessitated further investigation by using the observed undrained mechanism as the basis of an ellipsoidal cavity expansion model. An upper-bound energy approach was used to determine the load-settlement behaviour of circular shallow foundations on linear-elastic and non-linear clays, with yield defined using the von Mises' yield criterion. Linear-elastic soil results were consistent with those obtained from nite element analyses. The non-linear model, as described by a power-law, showed good agreement with both centrifuge experiment results and some real case histories. The single design curve developed through this model for normalised footing pressure and settlement could be used by practising engineers based on existing soil correlations or site investigations.