Gävle kommuns VA-huvudman Gästrike Vatten AB ansvarar för dricksvattenproduktionen i Gävle. För Gävles tätort tas vatten från Valboåsen som sträcker sig från öster om staden, genom staden och vidare norrut. Denna rapports syfte är att genom mätning av halten löst syre undersöka Valboåsens förbindelse till Gavleån. Detta kommer ge en ökad förståelse för åsens komplexitet. Resultatet kommer också att användas för att verifiera och utveckla den konceptuella modellen över flödena i åsens grundvattenmagasin som tagits fram av Midvatten AB. För att kunna mäta halten löst syre har en provtagning skett på grundvattenrör. I provtagningen ingick även så kallade slugtest där rörens kapacitet och anslutning till grundvattenmagasinet säkerställdes. Efter mätningen sammanställdes resultatet för att kunna jämföra halten löst syre i grundvattenrören mot den konceptuella modellen. Resultatet visade att halten löst syre i vattnet i de olika grundvattenrören stöder den konceptuella modellen till stora delar och gav även mer information om områden längs åsen där kunskap om flödesförhållandena tidigare var osäkra. Metoden i den utförda studien har visat stor användbarhet för att påvisa flödesförhållanden och ytvattenpåverkan i Valboåsen vilket visar att mätning av syrehalt kan vara mycket användbart i grundvattenutredningar angående ytvattenpåverkan. För att utöka studien av Valboåsen i framtiden behövs mer provtagning i grundvattenmagasinet på områden som inte ingick i denna studie. / Gävle municipality's water company is Gästrike Vatten AB. They manages the drinking water production for the City of Gävle. The production starts in the ridge of Valbo which extends between Överhärde (located in the south part of Valbo) and Strömsbro (located in the north part of Gavle). Purpose of this report is to measure the dissolved oxygen content in the aquifer throughout the whole area to investigate where the infiltration from the nearby Gavle River occurs. The aim of the study is to get a better understanding of the complexity of the Valbo ridge. The measurements will help to verify or modify the conceptual model of the directions of water flow in the Valbo ridge, developed by Midvatten AB. Dissolved oxygen content was measured through ground water pipes. To assess the pipes’ capacity and connection to the aquifer, slug tests were performed. The dissolved oxygen data were analyzed and compared with the conceptual model. The results showed that the dissolved oxygen content in the water supported the conceptual model to a large extent and also gave previously unknown information on some stretches of the ridge. The method shows great potential for additional future studies in Valbo ridge and elsewhere. To expand the study further, a need for more sampling of the aquifer throughout the areas that were not included in this study.

<p>In this thesis electron transfer reactions and diffusion of redox molecules in three different types of self-aggregated structures are investigated. Electrochemistry was used to investigate the redox potential and diffusion coefficients for redox active molecules with different polarity. The first aggregate system studied was the micellar phase. The role of electrostatic interactions in the stability of an amphiphilic viologen was investigated for differently charged micelles. It was concluded that the electrostatic environment changed the redox potential of the viologen. In differently charged micelles the redox potential was more negative compared to when the viologen was situated in micelles with the same charge.</p><p>The second structure investigated is a very fascinating phase, the bicontinuous cubic phase, with its continuous channels of water and an apolar bilayer. Its domains with different polarity made it possible to solvate both hydrophilic and hydrophobic molecules. An amphiphilic molecule will have its head-group at the interface between the apolar and polar part, and can move lateral within the bilayer. All molecules investigated made contact with and reacted at the surface of the electrode. The diffusion of water bound species diffusing in the water channels was 3-4 times slower than in water. Hydrophobic and amphiphilic molecules were much more hindered, probably because the cubic phase was not defect free.</p><p>The third kind of structure studied was a lamellar system. This phase is built up from planar bilayers that are stacked with a repeating distance and with water in between. A hydrophilic molecule was severely hindered to move in the direction perpendicular to the bilayer plane. Upon addition of the peptide melittin the current increased, due to pore formation in the bilayer.</p>

In this thesis electron transfer reactions and diffusion of redox molecules in three different types of self-aggregated structures are investigated. Electrochemistry was used to investigate the redox potential and diffusion coefficients for redox active molecules with different polarity. The first aggregate system studied was the micellar phase. The role of electrostatic interactions in the stability of an amphiphilic viologen was investigated for differently charged micelles. It was concluded that the electrostatic environment changed the redox potential of the viologen. In differently charged micelles the redox potential was more negative compared to when the viologen was situated in micelles with the same charge. The second structure investigated is a very fascinating phase, the bicontinuous cubic phase, with its continuous channels of water and an apolar bilayer. Its domains with different polarity made it possible to solvate both hydrophilic and hydrophobic molecules. An amphiphilic molecule will have its head-group at the interface between the apolar and polar part, and can move lateral within the bilayer. All molecules investigated made contact with and reacted at the surface of the electrode. The diffusion of water bound species diffusing in the water channels was 3-4 times slower than in water. Hydrophobic and amphiphilic molecules were much more hindered, probably because the cubic phase was not defect free. The third kind of structure studied was a lamellar system. This phase is built up from planar bilayers that are stacked with a repeating distance and with water in between. A hydrophilic molecule was severely hindered to move in the direction perpendicular to the bilayer plane. Upon addition of the peptide melittin the current increased, due to pore formation in the bilayer.

The objective of this study is to evaluate and compare, both technically and economically, various glucose feeding concentrations and different redox potential settings on ethanol production under very-high-gravity (VHG) conditions. Laboratory data were collected for process modeling and two process models were created by two individual process simulators. The first one is a simplified model created and evaluated by Superpro Designer. The second one is an accurate model created by Aspen Plus and evaluated by Aspen Icarus Process Evaluator (Aspen IPE). The simulation results of the two models were also compared. Results showed that glucose feeding concentration at 250±3.95 g/L to the fermentor resulted in the lowest unit production cost (1.479 $/kg ethanol in the Superpro model, 0.764 $/kg ethanol in the Aspen Plus model), with redox potential control effects accounted. Controlling redox potential at -150 mV increased the ethanol yield under VHG fermentation conditions while no significant influences were observed when glucose feeding concentration was less than 250 g/L. Results of product sales analysis indicated that for an ethanol plant with a production rate of 85~130 million kg ethanol/year, only maintaining the glucose feeding concentration to the fermentor at around 250 g/L resulted in the shortest payout period of 5.33 years in average,, with or without redox potential control. If 300±6.42 g/L glucose feeding concentration to the fermentor is applied, it is essential to have the redox potential only controlled at -150 mV in the fermentor to limit the process payout period within 6 years. In addition, fermentation processes with glucose feeding concentration at around 200 g/L to the fermentor were estimated to be unprofitable under all studied conditions. For environmental concerns, two disposal alternatives were presented for CO2 produced during fermentation process rather than emission into atmosphere. One is to sell CO2 as byproduct, which brought 1.52 million $/year income for an ethanol plant with a capacity of 100 million kg ethanol/year. Another option is to capture and transport CO2 to deep injection sites for geological underground storage, which is already a safe and mature technology in North America, and also applicable to many other sites around the world. This would roughly add 4.78 million dollars processing cost annually in the studied scenario. Deep injection of captured CO2 from ethanol plants prevents emission of CO2 into the atmosphere, thus makes it environmental friendly.

The objective of this study is to evaluate and compare, both technically and economically, various glucose feeding concentrations and different redox potential settings on ethanol production under very-high-gravity (VHG) conditions. Laboratory data were collected for process modeling and two process models were created by two individual process simulators. The first one is a simplified model created and evaluated by Superpro Designer. The second one is an accurate model created by Aspen Plus and evaluated by Aspen Icarus Process Evaluator (Aspen IPE). The simulation results of the two models were also compared. Results showed that glucose feeding concentration at 250±3.95 g/L to the fermentor resulted in the lowest unit production cost (1.479 $/kg ethanol in the Superpro model, 0.764 $/kg ethanol in the Aspen Plus model), with redox potential control effects accounted. Controlling redox potential at -150 mV increased the ethanol yield under VHG fermentation conditions while no significant influences were observed when glucose feeding concentration was less than 250 g/L. Results of product sales analysis indicated that for an ethanol plant with a production rate of 85~130 million kg ethanol/year, only maintaining the glucose feeding concentration to the fermentor at around 250 g/L resulted in the shortest payout period of 5.33 years in average,, with or without redox potential control. If 300±6.42 g/L glucose feeding concentration to the fermentor is applied, it is essential to have the redox potential only controlled at -150 mV in the fermentor to limit the process payout period within 6 years. In addition, fermentation processes with glucose feeding concentration at around 200 g/L to the fermentor were estimated to be unprofitable under all studied conditions. For environmental concerns, two disposal alternatives were presented for CO2 produced during fermentation process rather than emission into atmosphere. One is to sell CO2 as byproduct, which brought 1.52 million $/year income for an ethanol plant with a capacity of 100 million kg ethanol/year. Another option is to capture and transport CO2 to deep injection sites for geological underground storage, which is already a safe and mature technology in North America, and also applicable to many other sites around the world. This would roughly add 4.78 million dollars processing cost annually in the studied scenario. Deep injection of captured CO2 from ethanol plants prevents emission of CO2 into the atmosphere, thus makes it environmental friendly.

New evidence shows iron(II) oxidation is strongly coupled to nitrate reduction under anaerobic conditions in freshwater sediments and agricultural soils. However, the contribution of iron(II) oxidation to nitrate reduction is unknown. Furthermore, oxidation of manganese(II) by nitrate has been largely overlooked. This study investigated nitrate-dependent iron(II) and manganese(II) oxidation in an agricultural soil (Sadler silt loam) using stirred-batch kinetic techniques with native soil organic carbon (SOC) as the electron donor and included addition of amendments (hydrogen gas and wheat residue). In the presence of native SOC, nitrate-dependent Fe(II) and Mn(II) oxidation occurred at early stages of the reaction while organic carbon participated at longer times. Contributions of iron(II) and manganese(II) oxidation to nitrate reduction were 19% and 25%, respectively. This is significant in light of excess SOC relative to total Fe and Mn in the Sadler soil. Addition of hydrogen gas lowered the contribution of iron(II) oxidation to nitrate reduction to 10%, while addition of plant residue raised this value to approximately 55%. Manganese(II) oxidation contributed 50% to nitrate reduction under hydrogen amended conditions. These coupled processes involving Fe(II) and Mn(II) oxidation are an underappreciated aspect of the nitrogen cycle and merit consideration in future studies.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-09-04T14:24:54Z No. of bitstreams: 1 rodrigofragadealmeida.pdf: 7192674 bytes, checksum: 6ae959161ccde060e031fade5c149253 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-09-04T15:52:10Z (GMT) No. of bitstreams: 1 rodrigofragadealmeida.pdf: 7192674 bytes, checksum: 6ae959161ccde060e031fade5c149253 (MD5) / Made available in DSpace on 2018-09-04T15:52:10Z (GMT). No. of bitstreams: 1 rodrigofragadealmeida.pdf: 7192674 bytes, checksum: 6ae959161ccde060e031fade5c149253 (MD5) Previous issue date: 2018-07-30 / A busca por fontes renováveis de energia cresce cada vez mais em diversas regiões do mundo devido a demanda crescente e pela poluição gerada pelo uso de combustíveis fósseis. A energia solar é uma fonte renovável e inesgotável de energia que pode ser aproveitada diretamente por diversos tipos de células solares. Entre estes variadostipos, as células solares sensibilizadas por corante (DSSCs em inglês) se mostram promissoras devido à sua alta eficiência. Das variadas moléculas usadas como sensibilizador neste tipo de célula, as mais eficientes são os complexos polipiridínicos de rutênio(II). Diversas propriedades são importantes para que uma molécula seja aplicável em uma DSSC como um sensibilizador eficiente, entre elas uma larga e intensa absorção na região visível e infravermelho próximo do espectro eletromagnético e um potencial redox que permita que o sensibilizador seja regenerado pelo par redox,que também faz parte da célula. Neste trabalhofoi construída uma metodologia computacional baseada em dados experimentais que leva a resultados com pequenos desviospara o cálculo de potenciais redox e espectros eletrônicosde complexos cis-[Ru(R2-phen)(dcbpy)(NCS)2], sendo dcbpy a 4,4’-dicarboxi-2,2’-bipiridina e R2-phen a 1,10-fenantrolina com substituintes R nas posições 4 e 7.Parao cálculo de potenciais redox foi aplicadaa teoria do funcional da densidade (DFT) e paraasimulação dosespectroseletrônicosa DFT dependente do tempo (TDDFT). Com esta metodologia, novos complexos foram avaliados e suas propriedades estudadas visando estimar as suas eficiências se aplicados a DSSCs. Os novos complexos que apresentaram melhores resultados,em ordem do menos para o mais promissor,são aqueles com substituintes R = 2-piridil, 2-(5-etilfuril), 2-benzotiazolil. / The search for renewable energy sources grows increasingly in many regions of the world due to the crescent demand and pollution generated by the use of fossil fuels.The solar energy is a renewable and endless source of energy, which may be harnessed directly with different types of solar cells. Among thesevaried types, the dye-sensitized solar cells (DSSCs) present themselves to be promising owing to their high efficiency. Fromthe many molecules used as sensitizers in this kind of cell, the most efficient are thepolypyridinicruthenium(II) complexes. Different properties are important for a molecule to be applicable in a DSSC as an efficient sensitizer, among them a broad and intense absorption in the visible and near infrared region of the electromagnetic spectrum and a redox potential that allows the sensitizer to be regenerated by the redox couple,that is also part of the cell. In this work wasbuilt a computational methodologybased on experimental datawhich gives results with small deviations, for the calculation of redox potentials and electronic spectra of complexes cis-[Ru(R2-phen)(dcbpy)(NCS)2], where dcbpy is the4,4’-dicarboxylic acid 2,2’-bipyridineandR2-phenthe1,10-phenanthrolinewith R substituents on the positions 4 and 7. For the calculation of redox potentials, was applied the density functional theory (DFT) and for the electronic spectra simulations, the time-dependent DFT (TDDFT). With this methodology, new complexes where evaluated and their properties studied intending to estimate their efficiencies if applied to DSSCs. The new complexes that presented better results, in order from the less to the most promising, were those with substituents R = 2-pyridyl, 2-(5-ethylfuryl) and 2-benzothiazolyl.

No description available.

L’écosystème digestif est sous l’influence de facteurs abiotiques et biotiques qui déterminent son équilibre et par conséquent influencent la santé digestive de l'hôte. Chez le lapin en croissance, un déséquilibre de l’écosystème caecal est associé aux entéropathies, responsables de mortalités importantes en élevage. La compréhension des interactions biotope – biocénose digestive permettra la mise en oeuvre de stratégies pour garantir l'équilibre de cet écosystème. Ainsi, le rôle des facteurs biotiques de stabilité l’écosystème digestif, tels que des microorganismes exogènes probiotiques, fait actuellement l’objet de nombreuses études, mais leur mode d’action sur la biocénose et le biotope reste encore peu clair. L’objectif de notre travail est de contribuer à la compréhension du fonctionnement de l'écosystème caecal chez le jeune lapin, soumis ou non à un stress nutritionnel et en présence ou non d'une flore exogène ajoutée. Il s'agit aussi, de faire une approche comparative des effets d'un même probiotique (S. cerevisiae) dans cet écosystème et dans le rumen de la vache, pour mieux décrire les mécanismes d'action d'une levure probiotique sur les relations biocénose-biotope. Dans ce but, nous avons mis au point et validé pour le caecum du lapin la mesure du potentiel redox (Eh), pour mieux juger de l'état d'anaérobiose du biotope caecal. Nous avons également validé un nouvel indicateur de l’inflammation générale (haptoglobine sérique) en réponse à l'application d'un stress nutritionnel ou d'un état sanitaire déficient. Comparé au rumen, le biotope caecal est un milieu très anaérobie, puisque son potentiel redox moyen est de -220 mV et ne varie pas avec l’âge (de 28 à 64 jours). La biodiversité de la biocénose bactérienne caecale, calculée à partir de leur empreinte moléculaire (CE-SSCP) est en moyenne de 5,0 (indice de Simpson). Chez l'animal touché par un dysfonctionnement digestif, nous observons une élévation du niveau général de l'inflammation (+70% du taux d’haptoglobine sérique), associée à une chute de l'activité fermentaire caecal (-50%) et une hausse du pH (+ 0,7), mais qui n'est pas associée à des variations d'Eh caecal ou de la diversité bactérienne. L'application d'un stress nutritionnel (déficience en fibres) entraîne chez le lapin une baisse de la concentration caecale en AGV totaux (-25%) et une hausse du pH (+0,1). Cependant, la déficience en fibres n’a pas d'effet marqué sur le Eh caecal, dont la moyenne est de -210 mV. De même, la diversité bactérienne n’est pas modifiée (5,3) par la réduction de la teneur en fibres de l’aliment et la similarité observée est de 76%. La teneur de fibres dans l’aliment n’influence pas non plus le niveau d'inflammation générale. L’apport de levures vivantes dans la ration du lapin tend à augmenter la diversité bactérienne (+10%), et peut élever le potentiel redox caecal de 25 mV caecal. Il n’affecte cependant pas la structure du microbiote bactérien caecal (similarité= 99%). Elle n’entraîne pas non plus de variation du taux d’haptoglobine. L'ingestion de levures vivantes a permis l’amélioration de la santé digestive par la réduction de la mortalité (jusqu'à -50%) pendant les périodes de forte mortalité où le taux d’haptoglobine sérique augmente d’environ 70%. L’effet de la levure observé ici dans le caecum du lapin diffère de celui observé dans le rumen de la vache, pour lequel on observe une baisse du potentiel redox et une hausse du pH, ce qui favoriserait l’activité des bactéries anaérobies strict transformant le lactate en propionate. La levure stabiliserait donc le biotope (pH, potentiel redox) qui favoriserait la croissance ou l’activité de certaines bactéries. Cette hypothèse reste encore à confirmer pour l'écosystème caecal du lapin, à l'aide méthode appropriées. / The digestive ecosystem is influenced by abiotics and biotics factors that determined its balance and consequently influenced the host digestive health. In the young rabbit, caecal ecosystem disorders are largely responsible for nonspecific enteropathies that cause livestock losses. Understanding biotope/biocenosis interrelationships would allow the development of new strategies that preserve the ecosystem balance. Thus, the role of biotic factors that stabilise the digestive ecosystem, such as probiotics is extensively studied, however their effects on biocenosis and biotope remain unclear. The aim of our work is to improve our understanding of the caecal ecosystem functioning, submitted or not to a nutritional stress and with or without addition of an exogenous flora. We also aimed to compare the effects of the same probiotic (S. cerevisiae) in the caecum and in the rumen (dairy cow), to improve our knowledge on the mechanisms of action of yeast probiotic on biocenosis and biotope. We have developed and validated the measure of redox potential in the caecum. We also validated for the growing rabbit, a new indicator of the general inflammation (haptoglobin) in response to the application of nutritional stress or under a deficient sanitary status. Compared to the rumen, the caecal biotope is very anaerobic, since its redox potential is meanly of -220mV, and do not vary with age (35-63d old). The biodiversity of the bacterial community in the caecum, calculated from fingerprint technique (SSCP), reached meanly 5.0 (Simpson index). In the rabbit having a digestive trouble, the seric haptoglobin concentration increased by 70%, while caecal fermentative activity dropped by 50%. In parallel, the caecal pH increased (+0,7 unit) whereas the redox potential and the bacterial diversity remain unaffected in the caecum. When the young rabbit is submitted to a nutritional stress (fibre deficiency), the caecal volatile fatty acids concentration dropped by 25%, while the pH increased by 0.1 unit. However, the fibre deficiency did not affect the caecal redox potential (meanly -210 mV). Similarly, the bacterial biodiversity in the caecum was not modified (5,3) according to dietary fibre intake, as well the bacterial community structure. Besides, the haptoglobin concentration remained similar with fibre intake. The live yeast added in the diet tended to increase the bacterial diversity (+10%), and could slightly increase the caecal Eh (+25 mV). Yeast have no effect on the structure of rabbit caecal microbiota (bacteria only), where the similarity is 99%. It does not change the serum haptoglobin level. In return, yeast addition improved the digestive health by reducing mortality rate by 50%, particularly during periods of high mortality, when the serum haptoglobin increased by 70%. The effect of yeast described in the rabbit caecum differed from that found for the cow rumen: yeast decreased the redox potential and increased the pH that favors the strict anaerobic bacterial activity. The live yeast thus would stabilise the biotope (pH, Eh) and would favor the growth and activity of specific bacteria. However, this hypothesis still remains to be confirmed for the rabbit caecal ecosystem, using pertinent methodology.

Intracellular redox potential (IRP) is a measure of how oxidising or reducing the environment is within a cell. It is a function of numerous factors including redox couples, antioxidant enzymes and reactive oxygen species. Disruption of the tightly regulated redox status has been linked to the initiation and progression of cancer. However, there is very limited knowledge about the quantitative nature of the redox potential and pH gradients that exist in cancer tumour models. Multicellular tumour spheroids (MTS) are three-dimensional cell cultures that possess their own microenvironments, similar to those found in tumours. From the necrotic core to the outer proliferating layer there exist gradients of oxygen, lactate, pH and drug penetration. Tumours also have inadequate vasculature resulting in a state of hypoxia. Hypoxia is a key player in metabolic dysregulation but can also provide cells with resistance against cancer treatments, particularly chemotherapy and radiation therapy. The primary hypoxia regulators are HIFs (Hypoxia Inducible Factors) which under low O2 conditions bind a hypoxia response element, inhibiting oxidative phosphorylation and upregulating glycolysis which has two significant implications: the first is an increase in levels of NADPH/NADH, the main electron donors found in cells which impacts the redox state, whilst the second is a decrease in intracellular pH (pHi) because of increased lactate production. Thus, redox state and intracellular pHi can be used as indicators of metabolic changes within 3D cultures and provide insight into cellular response to therapy. Surface-Enhanced Raman Spectroscopy (SERS) provides a real-time, high resolution method of measuring pHi and IRP in cell culture. It allows for quick and potentially portable analysis of MTS, providing a new platform for monitoring response to drugs and therapy in an unobtrusive manner. Redox and pH-active probes functionalised to Au nanoshells were readily taken up by prostate cancer cell lines and predominantly found to localise in the cytosol. These probes were characterised by density functional theory and spectroelectrochemistry, and their in vitro behaviour modelled by the chemical induction of oxidative and reductive stress. Next, targeting nanosensors to different zones of the MTS allowed for spatial quantification of redox state and pHi throughout the structure and the ability to map the effects of drug treatments on MTS redox biology. The magnitude of the potential gradient can be quantified as free energy (ΔG) and used as a measurement of MTS viability. Treatment of PC3 MTS with staurosporine, an apoptosis inducer, was accompanied by a decrease in free energy gradients over time, whereas treatment of MTS with cisplatin, a drug to which they are resistant, showed an increase in viability indicating a compensatory mechanism and hence resistance. Finally, using this technique the effects of ionising radiation on IRP and pHi in the tumour model was explored. Following exposure to a range of doses of x-ray radiation, as well as single and multi-fractionated regimes, IRP and pHi were measured and MTS viability assessed. Increased radiation dosage diminished the potential gradient across the MTS and decreased viability. Similarly, fractionation of a single large dose was found to enhance MTS death. This novel SERS approach therefore has the potential to not only be used as a mode of drug screening and tool for drug development, but also for pre-clinical characterisation of tumours enabling clinicians to optimise radiation regimes in a patient-specific manner.