Doctor of Philosophy / Department of Chemical Engineering / Keith L. Hohn / The autothermal reforming and partial oxidation of hexadecane via Pt/Ni bimetallic nanoparticles on various ceria-based supports were investigated. Nanoparticles with Pt/Ni molar ratios ranging from 0/100 to 10/90 were loaded on ceria-based supports including cerium oxide, gadolinium-doped cerium oxide and cerium-doped zirconium oxide. The effect of the Pt/Ni molar ratio and the promotional effect of the support were studied by comparing the hydrogen yield. TPR and XPS analysis showed that there was a strong interaction between Ni and the CeO₂-ZrO₂ support, which led to enhancement of catalyst performance when the Pt/Ni ratio was low. The strong interaction between Ni and CeO₂-ZrO₂ support was induced by the formation of a solid solution between NiO and ZrO₂. In the case of bimetallic catalysts loaded on Gd₂O₃-CeO₂, no significant improvement in the catalytic activity of autothermal reforming was achieved until the Pt/Ni ratio reached 10/90. With C-snarf-1 as a pH-sensitive fluorescent probe, the local acidity on the surface of gradient aluminosilicate thin films and in the pore structure of mesoporous silicate films was explored. The single molecule emission ratio (I₅₈₀/I₆₄₀) of C-snarf-1 on the gradient aluminosilicate films showed similar results as previously reported for aluminosilicate mesoporous films. As the Al/Si ratio increases, the emission ratio declines, indicative of increased material acidity. In the case the mesoporous silicate films, much broader distributions of emission ratios were observed and are suggestive of significant heterogeneity in the pore structure of these films. The average emission ratio increased with a rise in pH until pH 6 or 7. A further rise in pH leads to a decline in emission ratio. Molecules with high mobility showed a narrow distribution and slightly lower average emission ratio when compared to data from all detected molecules. This observation implies a reduced heterogeneity for mesopores in which the molecules rapidly diffuse. The narrow distribution and lower average value of emission ratio at low pH, combined with the decrease in emission ratio induced by an increase in ionic strength may further indicate that the interaction between dye molecules and the pore surface impacts the emission ratio of the dye molecules.

The western portion of the Mississippi/Atwater fold belt in the Gulf of Mexico contains what is known as The Green Knoll Salt Dome. The creation and growth of this salt diapir is punctuated by salt deposition, salt migration, sediment loading, and is linked to the “Frampton” fold belt. An indicator of these growth periods is exhibited in an angular unconformity (halo-kinetic sequence boundary) that flanks the diapir. This unconformity developed during the Miocene-Pliocene chronostratigraphic boundary. The “Redwood” (Green Canyon 1001) prospect was drilled after the discovery of middle Miocene sands containing hydrocarbons in the Mad Dog field (GC 826). The objective Miocene sand in the “Redwood” borehole was thin due to this angular unconformity causing the sand to pinch out. An evaluation of seismic and well log data provided by Bureau of Ocean Energy Management indicated that the unconformity might not provide the seal needed to trap hydrocarbons on the flank of the salt dome, or it did not allow enough sand to be deposited. A palinspastic structural restoration of the Green Knoll Salt Dome revealed that the growth of the Green Knoll and Frampton are connected. It is still possible that if a well were to be drilled further down dip from where The “Redwood” prospect was drilled, one may find a potential hydrocarbon reservoir.

With the depletion of hydrocarbon fuels, the hydrogen-hydrocarbon combustion system provides a good solution for the transition period from a hydrocarbon-based energy sys- tem to a hydrogen-based energy system because of its desirable combustion characteristics and the low level of modification to current combustion systems. Though extensive re- search has been carried out to investigate the combustion process of hydrogen-hydrocarbon fuels, no experiments have been reported to study the Particulate Matter (PM) formations in hydrogen-hydrocarbon combustion systems. To measure the PM concentrations in a laminar diffusion flame, a new optical diagnostic technique, called Cone-Beam Tomographic Three Colour Spectrometry (CBT-TCS) has been developed to measure the spatially distributed temperature, soot diameter and soot volume fraction. This technique is based on the principle of three colour pyrometry, but uses a more rigorous light scattering model to calculate the soot diameter and soot volume fraction. The cone beam tomography technique has also been used to reconstruct the 3D property fields from the 2D flame images. The detailed theoretical principles, the exper- imental setup, the optical considerations, the reconstruction algorithm and the sensitivity analysis are all introduced. The CBT-TCS technique has been successfully applied to several laminar diffusion flames to study the PM formation. The temperature and soot volume fracction profiles measured by CBT-TCS for a ethylene laminar diffusion flame are consistent with the data reported by Snelling et al. [77]. The helium-ethylene-air flame tests show that adding helium reduces the PM formation (due to the dilution effect). The hydrogen-ethylene-air flame tests show that adding hydrogen is more effective in reducing the PM formation due to the combined effect of dilution and direct chemical reaction. A PM sampling system has also been de- veloped to verify the PM size distributions measured by CBT-TCS. The comparison results show that the CBT-TCS tends to overestimate the particle size. Several optical engine experiments have also been undertaken to investigate the effect of adding hydrogen on the PM emissions from a Gasoline Direct Injection (GDI) engine. The hydrogen-ethylene engine tests show that adding hydrogen can reduce the PM emissions without sacrificing the power output. The hydrogen-base fuel (65% isooctane and 35% toluene) tests show that adding hydrogen can improve the combustion stability and reduce the PM emissions, especially at low load. Adding 5% stoichiometric of hydrogen can reduce the total PM number concentration by 90% for a stoichiometric mixture and 97% for richer mixture at low load. At high load, adding 10% stoichiometric of hydrogen can also reduce the total PM number concentration by 85% for richer mixture but has little effect upon the stoichiometric mixture.

Determinações do consumo e da digestibilidade, atravé s do método de coleta total de fezes, foram realizadas em 8 veados–catingueiros (Mazama gouazoubira) recebendo uma dieta peletizada composta por 63,9% de feno de alfafa, 16,9% de amido de milho, 14,7% de levedura (Saccharomyces cerevisiae), 2,5% de melaço, 1,5% de um premix vitamínico-mineral e 0,5% de cloreto de sódio em base seca. As estimativas dos coeficientes de digestibilidade foram determinadas paralelamente através do uso de indicador fecal (n-alcanos) com o intuito de validar a metodologia para esses pequenos ruminantes. O consumo médio de matéria seca e água durante o período de coleta foram: 24g ± 2,5 e 67 mL ± 11,5 por quilo de peso vivo (PV), sendo que os animais não apresentaram perdas de peso durante o período experimental. Quando expresso em peso metabólico (PV0,75), os animais consumiram em média 48g ± 5,2 de matéria seca e 136,4 mL ± 23,8 de água. O consumo de energia digestível foi em média 1.089 kcal/dia. As médias dos coeficientes de digestibilidade aparente obtidas através da coleta total de fezes, foram de 61,6% ± 1,7 para matéria seca, 63,9% ± 1,6 matéria orgânica, 69,7% ± 3,4 nitrogênio, 31,7% ± 3,7 fibra em detergente neutro, 45,2 ± 2,4 celulose e 18,8 ± 5,6 para a lignina. Os coeficientes de digestibilidade estimados para as diferentes frações através da utilização dos n-alcanos C31 e C33 se mostraram precisos e acurados em relação aos coeficientes de digestibilidade observados por coleta total quando as recuperações fecais foram incluídas nos cálculos de digestibilidade (P>0,05). Consistente com valores obtidos em ovinos, as recuperações fecais dos n-alcanos de cadeia ímpares aumentaram com o aumento do número de carbonos da cadeia de hidrocarboneto sendo que estes valores poderão ser utilizados em futuros estudos onde se deseja determinar a composição botânica da dieta dos cervídeos. / Feed intake and digestibility estimates were determined by the total fecal collection method of 8 deer (Mazama gouazoubira) receiving a pelleted diet of 63.9% alfalfa hay, 16.9% corn starch, 14.7% yeast (Saccharomyces cerevisiae), 2.5% mollasses, 1.5% mineral-vitamin mix, and 0.5% NaCl on DM basis. n-alkane tracer method was used in parallel with total fecal collection to validate its application on wild small ruminants. The mean DM feed intake and water intake during the collection period were 24g ± 2.5 and 67 mL ± 11.5 per kg BW, and the animals did not present weight losses during the experimental period. When these values were expressed on kg of metabolic live weight, the animals consumed 48g ± 5.2 of DM and 136.4 mL ± 23.8 of water. Digestible energy intake was estimated at 1,089 kcal/day. The mean coefficients of apparent digestibility observed by total fecal collection for dry matter was 61.6% ± 1.7; organic matter 63.9% ± 1.6, nitrogen 69.7 % ± 3.4, neutral detergent fiber 31.7% ± 3.7, cellulose 45.2 % ± 2.4, and lignin 18.8% ± 5.6. The digestibility coefficients estimated for the different fractions by the n-alkanes C31 and C33 were accurate when compared to those observed by the total fecal collection method when feces recovery was included on digestibility calculations (P>0.05). Consistent with values obtained in sheep, the fecal recoveries of the odd chain n-alkanes was greater with the increase of the number of carbons of the chain of hydrocarbon and these values can be used in future studies to determine the botanical composition of the deer’s diet.

A água subterrânea abastece grande parte da população e sua contaminação é assunto de interesse público. Os postos de combustíveis são fontes potenciais de contaminação, devido à sua extensa malha de distribuição e pelo armazenamento de produto ser predominantemente subterrâneo. Dentre os métodos para detecção de hidrocarbonetos, os geofísicos proporcionam investigação em maiores extensões, com mais rapidez e menor custo. Este estudo apresenta os resultados de quatro métodos geofísicos (eletrorresistividade, polarização induzida, georradar e eletromagnético EM-34) na investigação de dois perfis a jusante de um posto de combustível com histórico de vazamento. Os objetivos foram de detectar a pluma de contaminação e identificar qual dos métodos apresenta os melhores resultados nesta situação. A eletrorresistividade apresentou a melhor correlação com a zona contaminada e com as análises químicas. Os dados da polarização induzida também se relacionaram com a pluma. Os valores do sistema EM-34 ficaram aquém das expectativas. Os do georradar não possibilitaram nenhuma correlação com o substrato contaminado, certamente devido a pouca profundidade de penetração. Foi constatado que a contaminação por hidrocarbonetos não oferece assinatura geoelétrica previsível, devido às condições dinâmicas do campo e suas inter-relações. Enquanto muitos trabalhos associam baixas resistividades aos vazamentos antigos, outros trabalhos mostram o inverso. Neste estudo, a anomalia encontrada apresentou alta resistividade associada às cargabilidades mais altas. / A large portion of the population is supplied with groundwater, and this is a matter of public interest. Gas stations are potential sources of contamination for its extensive distribution network and for the underground storage. Among the existing methods for hydrocarbon detection, the geophysical ones provide a larger range, faster results at smaller costs. This work presents the results of four geophysical methods (electrical resistivity, induced polarization, ground penetrating radar and electromagnetic EM-34) applied to the study of two profiles downwards of a leaking gas station. The objectives were detecting the contamination plume and identify which of the methods employed presents the best results on this site. The electrical resistivity method presented the best correlation with the contaminated zone and chemical analysis. The results of the induced polarization were also associated with the contamination plume. Values obtained with the EM-34 didn?t fulfill the expectations. GPR data didn?t correlate with the contaminated substrate, certainly due to the shallow penetration depth. It was observed that the hydrocarbon contamination does not offer a predictable geoelectrical signature, due to the dynamic conditions of the field and its inter relations. Whilst several paper associate low resistivities to older leakages, in other papers it was found the opposite. In this case study, the anomaly has shown characteristics of high resistivity associated to higher chargeabilities.

A ativação de Receptores de Hidrocarbonetos de Arila (AhR) é associada ao desenvolvimento de doenças cardiovasculares (DCV), dentre elas a aterogênese. Entretanto, não foi elucidado se a ativação do AhR por compostos/moléculas endógenas influenciaria o desenvolvimento de placas vulneráveis. Diante do exposto, o presente estudo testou a hipótese que a ativação do AhR mediada por compostos/moléculas endógenas contribui para o processo aterogênico e vulnerabilidade da placa aterosclerótica de camundongos nocautes para apoliproteína E (ApoE-/-). Nosso estudo mostrou que um dispositivo cilíndrico (cast), que promove estresse de cisalhamento baixo (ECB) e estresse de cisalhamento oscilatório (ECO), causa o desenvolvimento de placas ateroscleróticas com fenótipos vulnerável e estável de forma tempo dependente, em carótidas de camundongos ApoE-/- submetidos a dieta western. Regiões com ECB, apresentaram aumento na expressão de IL-1?, TNF-?, MMP-12 e do AhR, sugerindo que este receptor contribui com o processo inflamatório em placas vulneráveis, posto que ele regula a expressão gênica de mediadores pró-inflamatórios. O tratamento com CH223191 (antagonista AhR) diminuiu a vulnerabilidade da placa aterosclerótica, pois reduziu a quantidade de macrófagos, lipídeos, a geração de espécies reativas de oxigênio (EROs) e aumentou a quantidade de células de musculo liso (CML) em regiões com ECB. Além disso, o CH223191 reduziu a expressão de IL-1? em placas ateroscleróticas presentes no arco aórtico e a hipercolesterolemia dos camundongos ApoE-/-. Outrossim, nossos achados apontam que o CH223191 evita o prejuízo induzido por oxLDL na vasodilatação da artéria aorta de camundongos C57BL/6J. Em células endoteliais, a ativação do AhR mediada por oxLDL é responsável pela produção de IL-1?, evento bloqueado pelo CH223191. Nossos achados destacam o AhR como alvo promissor na compreensão de DCV e possível alvo terapêutico na aterosclerose. / Aryl hydrocarbon receptor (AhR) activation is associated with the development of cardiovascular diseases, including atherosclerosis. However, it is unknown whether AhR activation by endogenous compounds/molecules plays a role in the development and vulnerability of the atherosclerotic plaque. We hypothesized that AhR activation by endogenous compounds/molecules promotes atherogenesis and contributes to the formation of vulnerable plaques in apolipoprotein E knockout mice (ApoE-/-). A shear stress modifier (cylindrical device referred to as cast) was placed in the carotid arteries of ApoE-/- mice, creating areas of lower shear stress (LSS) and oscillatory shear stress (OSS), and inducing the development of atherosclerotic vulnerable and stable plaques, respectively, in a time-dependent manner. LSS regions exhibited increased expression of IL-1?, TNF-?, MMP-12 and AhR. Considering that AhR activation leads to transcription of proinflammatory markers transcription, it is possible that AhR expression in LSS regions is associated with the inflammatory process. Treatment with an AhR antagonist (CH223191) reduced lipid and macrophage accumulation and increased the smooth muscle cell content in LSS regions. Additionally, CH223191 reduced IL-1? expression in atherosclerotic plaques in the aortic arch from hypercholesterolemic ApoE-/- mice. Furthermore, CH223191 prevented oxLDL-induced vascular dysfunction (reduced ACh vasodilation) in C57BL/6J. In endothelial cells, oxLDL induced IL-1? release by mechanisms dependent on AhR activation, an effect prevented by CH223191. Our findings point to AhR as a possible new therapeutic target in cardiovascular diseases, including atherosclerosis.

A ativação de Receptores de Hidrocarbonetos de Arila (AhR) é associada ao desenvolvimento de doenças cardiovasculares (DCV), dentre elas a aterogênese. Entretanto, não foi elucidado se a ativação do AhR por compostos/moléculas endógenas influenciaria o desenvolvimento de placas vulneráveis. Diante do exposto, o presente estudo testou a hipótese que a ativação do AhR mediada por compostos/moléculas endógenas contribui para o processo aterogênico e vulnerabilidade da placa aterosclerótica de camundongos nocautes para apoliproteína E (ApoE-/-). Nosso estudo mostrou que um dispositivo cilíndrico (cast), que promove estresse de cisalhamento baixo (ECB) e estresse de cisalhamento oscilatório (ECO), causa o desenvolvimento de placas ateroscleróticas com fenótipos vulnerável e estável de forma tempo dependente, em carótidas de camundongos ApoE-/- submetidos a dieta western. Regiões com ECB, apresentaram aumento na expressão de IL-1?, TNF-?, MMP-12 e do AhR, sugerindo que este receptor contribui com o processo inflamatório em placas vulneráveis, posto que ele regula a expressão gênica de mediadores pró-inflamatórios. O tratamento com CH223191 (antagonista AhR) diminuiu a vulnerabilidade da placa aterosclerótica, pois reduziu a quantidade de macrófagos, lipídeos, a geração de espécies reativas de oxigênio (EROs) e aumentou a quantidade de células de musculo liso (CML) em regiões com ECB. Além disso, o CH223191 reduziu a expressão de IL-1? em placas ateroscleróticas presentes no arco aórtico e a hipercolesterolemia dos camundongos ApoE-/-. Outrossim, nossos achados apontam que o CH223191 evita o prejuízo induzido por oxLDL na vasodilatação da artéria aorta de camundongos C57BL/6J. Em células endoteliais, a ativação do AhR mediada por oxLDL é responsável pela produção de IL-1?, evento bloqueado pelo CH223191. Nossos achados destacam o AhR como alvo promissor na compreensão de DCV e possível alvo terapêutico na aterosclerose. / Aryl hydrocarbon receptor (AhR) activation is associated with the development of cardiovascular diseases, including atherosclerosis. However, it is unknown whether AhR activation by endogenous compounds/molecules plays a role in the development and vulnerability of the atherosclerotic plaque. We hypothesized that AhR activation by endogenous compounds/molecules promotes atherogenesis and contributes to the formation of vulnerable plaques in apolipoprotein E knockout mice (ApoE-/-). A shear stress modifier (cylindrical device referred to as cast) was placed in the carotid arteries of ApoE-/- mice, creating areas of lower shear stress (LSS) and oscillatory shear stress (OSS), and inducing the development of atherosclerotic vulnerable and stable plaques, respectively, in a time-dependent manner. LSS regions exhibited increased expression of IL-1?, TNF-?, MMP-12 and AhR. Considering that AhR activation leads to transcription of proinflammatory markers transcription, it is possible that AhR expression in LSS regions is associated with the inflammatory process. Treatment with an AhR antagonist (CH223191) reduced lipid and macrophage accumulation and increased the smooth muscle cell content in LSS regions. Additionally, CH223191 reduced IL-1? expression in atherosclerotic plaques in the aortic arch from hypercholesterolemic ApoE-/- mice. Furthermore, CH223191 prevented oxLDL-induced vascular dysfunction (reduced ACh vasodilation) in C57BL/6J. In endothelial cells, oxLDL induced IL-1? release by mechanisms dependent on AhR activation, an effect prevented by CH223191. Our findings point to AhR as a possible new therapeutic target in cardiovascular diseases, including atherosclerosis.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-03-23T18:24:55Z No. of bitstreams: 1 estudos_microbiologicos.pdf: 1899296 bytes, checksum: fc614dda615f2e763955219f31df88d4 (MD5) / Made available in DSpace on 2015-03-23T18:24:55Z (GMT). No. of bitstreams: 1 estudos_microbiologicos.pdf: 1899296 bytes, checksum: fc614dda615f2e763955219f31df88d4 (MD5) Previous issue date: 2012-02-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / FINEP - Financiadora de Estudos e Projetos / FIERGS - Federação das Indústrias do Rio Grande do Sul / Sebrae - Serviço Brasileiro de Apoio à Micro e Pequenas Empresas / Os compostos conhecidos como TPH (Total Petroleum Hydrocarbon) e BTEX (Benzeno, Tolueno, Etilbenzeno e Xileno) são contaminantes oriundos de derivados do petróleo como a gasolina e o diesel. Eles são provenientes de problemas que ocorrem com o armazenamento subterrâneo de combustíveis, principalmente em postos de abastecimento. São encontrados em águas subterrâneas de áreas contaminadas por hidrocarbonetos, que causam impacto ambiental. Exemplos destes impactos podem ser: inutilização dos pontos de captação de água potável, mortandade de flora e fauna aquática, inutilização de lavouras e plantações, impermeabilização de solos, redução de microrganismos do solo, morte de plantas e árvores, além de riscos de explosão devido à evaporação do produto. A presente pesquisa avaliou, por meio de métodos microbiológicos, como por exemplo: crescimento microbiano, meio seletivo para fungos, isolamento, detecção de ramnolipídios e teste de degradabilidade, os processos envolvidos com a recuperação de áreas degradadas por hidrocarbonetos através do isolamento e caracterização dos microrganismos presentes no local contaminado. Foram testadas diferentes concentrações de diesel (1%, 2%, 3%, 5%, 10%, 30% e 50%) para avaliação do crescimento de microrganismos indígenas de áreas contaminadas de postos de combustíveis, além de verificar-se o potencial de degradação de hidrocarbonetos. Acompanhamentos visuais e microscópicos, além do monitoramento do decréscimo do parâmetro TPH em diversos ensaios foram realizados. Os resultados mostraram que foi possível isolar e caracterizar os microrganismos presentes no local contaminado, tendo sido verificado dois diferentes morfotipos: bactérias e fungos. No total dos ensaios realizados 81,8% eram bactérias Gram negativas, 4,5% bactérias Gram positivas e 13,7% fungos. Nos ensaios com menor concentração de diesel (1%) houve o melhor crescimento de microrganismos o que resultou em maior eficiência no decréscimo do parâmetro de TPH. Esses resultados indicam a possibilidade de degradação de diesel em áreas contaminadas por via biológica, com ressalvas para altas concentrações do hidrocarboneto, quando o crescimento microbiano, nas condições ensaiadas, foi afetado. / The compounds known as TPH (Total Petroleum Hydrocarbon) and BTEX (Benzene, Toluene, Ethylbenzene and Xylene) contaminants are derived from petroleum products like gasoline and diesel. They are problems that occur from the underground storage of fuels, especially in gas stations. They are found in areas of groundwater contaminated with hydrocarbons, which cause environmental impact. Examples of these impacts may include: destruction of the points of capitation of drinking water, the death of aquatic flora and fauna, destruction of crops and plantations, soil sealing, reduction of soil microorganisms, death of plants and trees, and hazards of explosion due to the evaporation of the product. This research evaluated through microbiological methods, such as: microbial growth, selective medium for fungi, isolation, detection ramnoli and biodegradability test, the processes involved in the recovery of degraded sites by hydrocarbons through at the isolation and characterization of microorganisms present on the site contaminated. Different concentrations of diesel oil (1%, 2%, 3%, 5%, 10%, 30% and 50%) were tested to assess the growth of microorganisms indigenous of contaminated gas station, and to identify the potential degradation of hydrocarbons. Accompaniments visual and microscopic, in addition to monitoring the reduction of the parameter TPH in several tests were performed. The results showed that it was possible to isolate and characterize microorganisms in the contaminated site, where two different morphotypes were observed: bacteria and fungi, and 81.8% Gram-negative bacteria, Gram-positive bacteria 4.5% and 13.7% fungi. In tests with lower concentrations of diesel oil (1%) had the better growth of microorganisms resulting in greater efficiency in reduction of TPH. These results indicate the possibility of degradation of diesel in areas contaminated by biological, with exceptions for high concentrations of hydrocarbon, when microbial growth was affected.

OBJECTIVE: The aryl hydrocarbon receptor (AhR) translocates to the nucleus and binds to the aryl hydrocarbon receptor nuclear translocator (ARNT) to regulate biological responses upon ligand activation. The aim of this study was to measure the effects of activation or inhibition of AhR activity on basal and glucose-stimulated insulin secretion (GSIS) from clonal pancreatic β-cells (INS-1) cultured under normal and glucolipotoxic (GLT) conditions (high glucose and fatty acid). METHODS: Insulin content and secretion were measured utilizing homogenous time-resolved fluorescence (HTRF) insulin assay kit (cisbio). Cells cultured in RPMI media containing 5 mM and 11 mM glucose were pre-incubated with the receptor agonist FICZ or antagonist CH223191 for 96 hours. Insulin secretion over 2 hours was reported as ng/million cells. Intracellular lipid was measured by fluorescence after Nile red staining. RESULTS: Incubation of INS-1 cells with 11 mM glucose and fatty acid increased lipid droplets, basal insulin secretion and inhibited GSIS compared to cells cultured in 4 mM glucose, characteristic of GLT. Incubation of INS-1 cells with 11 mM glucose alone also exhibited GLT characteristics. INS-1 cells cultured at 11 mM glucose and treated with antagonist (1.25 - 10 μM) had decreased lipid content and improved insulin secretion compared to cells cultured in 11 mM glucose alone. INS-1 cells cultured in 5 mM glucose and treated with the AhR agonist (1.25 - 10 μM) exhibited increased intracellular lipid and impaired insulin secretion. CONCLUSION: The AhR may play a mediatory role in the development of GLT in pancreatic β-cells cultured in excess nutrients and β-cell specific activator or inhibitor ligands of this receptor could potentially be a targeted therapeutic treatment of diabetes.

The increase in greenhouse gas (GHG) concentrations in the atmosphere, as well as the high rate of depletion of hydrocarbon-based resources have become a global concern. A major source of emissions of hydrocarbon vapours occur during loading and offloading operations in crude oil shuttle tanker transportation. The emitted gases have a typical composition of 60 % N2, 10 % CO2, 5% O2, 5 % C3H8, 10% CH4, 5% C2H6 and 5 % higher hydrocarbons. As a result, various methods aimed to add value to GHG to produce valuable fuels and chemical feedstock are being developed. This work incorporates the use of silica, polyurethane/zeolite and y-type zeolite membrane on an alumina support to selectively permeate methane and carbon dioxide from inert gases and higher hydrocarbons. The recovered gas is upgraded by dry reforming reactions employing rhodium/alumina membrane incorporated into a shell and tube reactor. Mixed gas permeation tests have been carried out with the permeate and feed gases sent to the online gas chromatograph (GC) equipped with a mass spectrometry (MS) detector and an automated 6-port gas sampling valve with a 30 mm HP- Plot Q column. The question is what mesoporous membrane can be highly selective for the separation of methane and carbon dioxide from inert gases and higher hydrocarbons, and what is the effect of temperature and feed gas pressure on the conversion of separated gases? Characterisation of the modified membranes was carried out using nitrogen physisorption measurements and showed the hysteresis isotherms corresponding to type IV and V, which is indicative of a mesoporous membrane. The surface area and the pore size were determined using the Barrett, Joyner, Halenda (BJH) desorption method, which showed the silica membrane had a larger surface area (10.69 m2 g-1) compared to zeolite (0.11 m2 g-1) and polyurethane/zeolite membrane (0.31 m2 g-1). Fourier Transform Infrared spectroscopy, Scanning Electron Microscope and Energy Dispersive X-ray Analysis confirmed the asymmetric deposition of silica, polyurethane, rhodium and zeolite crystals in the matrix of the alumina support. Single gas permeation tests showed that the synthesised y-type zeolite membrane at 293 K had a CH4/C3H8 selectivity of 3.11, which is higher than the theoretical value of 1.65. The permeating CH4 and C3H8 flux at 373 K and a pressure of 1 x 105 Pa was 0.31 and 0.11 mol s-1 m-2 respectively proving that zeolite has molecular sieving mechanism for separation of methane and propane. The silica membrane exhibited higher effectiveness for the separation of CO2 than the other membranes. For methane dry reforming using a supported rhodium membrane, an increase of the reaction temperature from 973 K to 1173 K showed an increase in conversion rate of CO2 and CH4 from less than 20% to over 90% while increasing the gas hourly space velocity (GHSV) did not have a noticeable effect. The study revealed the high potential of the zeolite and rhodium membrane for gas separation and dry reforming reactions concept in creating value-added carbon-based products from CO2 and CH4.