To see the other types of publications on this topic, follow the link: Solute-solute.
Dissertations / Theses on the topic 'Solute-solute'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Solute-solute.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Neale, Peta Anne. "Influence of solute-solute interactions on membrane filtration." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4106.
Full textAbstract:
An understanding of solute-solute interactions is essential for aquatic systems as this can affect the fate and behaviour of micropollutants in the environment and engineered systems. Despite the importance of solute-solute interactions there is a general lack of understanding which may be attributed to the fact that many engineering models overlook solute-solute interactions and that the quantification of such interactions is inherently difficult. When solute-solute interactions are considered, they are often studied at unrepresentative concentrations and do not consider the influence of organic matter type or solution chemistry. Steroidal hormones, such as estradiol and estrone, were selected as model micropollutants as they are ubiquitous in the aquatic environment due to constant introduction of wastewater effluent, and can have implications for growth and development of organisms including impaired fertility and behavioural abnormalities. The purpose of this study was to develop a methodology to quantify solute-solute interactions at environmental concentrations, and to determine the implications of such interactions in membrane filtration. A solid-phase microextraction (SPME) technique was developed to quantify solutesolute interactions at environmental (low) concentrations. Using SPME, organic matter-water partition coefficients (log KOM) were measured for a range of steroidal hormones including estradiol, estrone, progesterone and testosterone with different organic matter types such as humic acid. The dominant mechanism of hormoneorganic matter interactions was identified as hydrogen bonding. In the case of estrone and progesterone the log KOM values were significantly influenced by organic matter type and concentration, as well as solution chemistry. No difference was observed for estradiol and testosterone due to generally weaker sorption to organic matter. Previous studies have indicated that the presence of organic matter can alter micropollutant retention in membrane filtration. Much of the current literature focuses on solute-membrane interactions, as the influence of solute-solute interactions are typically difficult to determine in membrane filtration. Therefore, hormone-organic matter interactions were studied to determine if this interaction had an influence on hormone removal by ultrafiltration (UF) using a range of molecular weight cut-off (MWCO) membranes. The results indicated increased retention of estrone in the presence of humic acid, while organic matter concentration and solution chemistry influenced retention by affecting solute-solute interactions. The findings of this study indicate the importance of solute-solute interactions in membrane filtration and experimental log KOM results were used to quantify the findings and elucidate the influences of 1) membrane sorption, 2) solute-solute interactions and 3) solute-foulant interactions. Further, the removal of steroidal hormones using a magnetic ion exchange (MIEX®) resin with a range of MWCO UF membranes was studied as such sorbents can be used to improve micropollutant removal in wastewater treatment. Greater removal with IX-UF was observed compared to UF alone and the main hormone removal mechanisms were sorption to MIEX® and solute-fouling interactions. The findings of this study indicate that it is indeed possible to quantify solute-solute interactions at environmental concentrations using SPME, with hydrogen bonding being the main mechanism of interaction for steroidal hormones and organic matter. Further, micropollutant retention by membrane filtration can be influenced by solutesolute interactions.
2
Ghosh, Gargi. "Investigation on solute-solute, solute-solvent and solvent-solvent interactions prevailing in some liquid system." Thesis, University of North Bengal, 2009. http://hdl.handle.net/123456789/1351.
Full text
3
Mandale, Stephen John. "Nanofiltration of multi-solute systems : solute interactions and theory." Thesis, Swansea University, 2005. https://cronfa.swan.ac.uk/Record/cronfa42669.
Full textAbstract:
From the outset, membrane researchers have studied the behaviour and governing processes of membrane separations. Theoretical representation of membrane transport systems is central to membrane research and the most recent investigations have considered single and binary solute systems of charged and uncharged species. A gap in the research was detected with respect to systems of combined charged (dissociated) and uncharged (non-dissociated) species. Thus these systems were explored from both a practical-experimental and theoretical perspective. The result of experimental investigation into combined systems of charged/uncharged solutes, was an observation of negative rejections for uncharged solutes in the presence of high salt concentrations. This is a phenomenon that was not observed elsewhere and in general the rejection of uncharged solutes was attributed to steric factors hence a direct interaction between salts and neutral solutes was not suggested. The reliability of the negative rejection observations was established through a discussion of experimental error and a consideration of concentration polarisation. It was found that the error was negligible and that the measured negative rejections (approximately -10% in some cases) were not attributable to variation in the results caused by external influences. An analysis of concentration polarisation only served to amplify the negative rejection observed, since real rejection (that at the membrane surface) exhibited greater negativity than the observed rejection. The observed phenomenon was discussed with respect to current forms of membrane transport theories. The semi-black box technique proposed by Spiegler and Kedem and later modified by Van der Bruggen and co-workers was found to provide a reasonable fit of the experimental data where valance was taken to be a non-integer fitting parameter. Errors in the Fortran implementation of the Bowen and Welfoot development of the Donnan Steric Partitioning Model (DSPM) prevented this transport theorem from being explored in relation to the measured phenomenon. Thus it was a recommendation of this work that this theory should be considered in more depth.
4
Llerar, Meza Gerónimo. "Upscaling nonreactive solute transport." Doctoral thesis, Universitat Politècnica de València, 2009. http://hdl.handle.net/10251/5848.
Full textAbstract:
This thesis focuses on solute transport upscaling. Upscaling of solute transport is usually required to obtain computationally efficient numerical models in many field applications such as, remediation of aquifers, environmental risk to groundwater resources or the design of underground repositories of nuclear waste. The non-Fickian behavior observed in the field, and manifested by peaked concentration profiles with pronounced tailing, has questioned the use of the classical advection-dispersion equation to simulate solute transport at field scale using numerical models with discretizations that cannot capture the field heterogeneity. In this context, we have investigated the use of the advection-dispersion equation with mass transfer as a tool for upscaling solute transport in a general numerical modeling framework.
Solute transport by groundwater is very much affected by the presence of high and low water velocity zones, where the contaminant can be channelized or stagnant. These contrasting water velocity zones disappear in the upscaled model as soon as the scale of discretization is larger that the size of these zones. We propose, for the modeling solute transport at large scales, a phenomenological model based on the concept of memory functions, which are used to represent the unresolved processes taking place within each homogenized block in the numerical models.
We propose a new method to estimate equivalent blocks, for which transport and mass transfer parameters have to be provided. The new upscaling technique consists in replacing each heterogeneous block by a homogeneous one in which the parameters associated to a memory functions are used to represent the unresolved mass exchange between highly mobile and less mobile zones occurring within the block. Flow upscaling is based on the Simple Laplacian with skin, whereas transport upscaling is based in the estimation of macrodispersion and mass transfer parameters as a result of the interpretation of the rLlerar Meza, G. (2009). Upscaling nonreactive solute transport [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/5848
Palancia
5
De, Munari Annalisa. "Removal mechanisms of organic and inorganic solutes in raw, upland drinking water by nanofiltration : influence of solute-solute and solute-membrane interactions." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/7881.
Full textAbstract:
Nanofiltration (NF) membranes have been applied successfully for the removal of inorganic and organic pollutants, including micropollutants, from drinking water for the past two decades. However, a complete and quantitative understanding of NF removal mechanisms has yet to be achieved. Quantifying the factors governing solute transport and retention by NF is necessary in order to achieve higher treatment efficiency at a lower cost. The aim of this research was to contribute to the current state of the knowledge of the mechanisms of solute retention and transport by NF membranes. The focus was on evaluating the contribution of solute-solute interactions and solute-membrane interactions on solute removal and transport mechanisms. To the knowledge of the author, at the start of this research there was a lack of understanding of the simultaneous impacts of both interactions on the performance of NF membranes, which renders this research novel. To highlight challenges faced by modern membrane plants and identify inorganic and organic pollutants of interest, a study of water quality in Scotland was carried out. Experiments were performed in dead-end stirred cells using two commercial NF membranes, TFC-SR2 and TFC-SR3 provided by Koch, which were extensively characterized. Radiolabeled Endosulfan (ES, 10 μg/L), manganese (5-1,500 mg/L) and Humic Acids (HA, 5-250 mgC/L) were spiked in synthetic water with background electrolyte (1 mM NaHCO3 and 20 mM NaCl). Calcium (Ca, 2.5 mM) was employed in fouling experiments. The influence of the complexation of solutes with HA on solute retention by NF was for the first time quantified for the solute concentrations employed in this study. It was found that manganese retention was influenced by membrane pore size and charge (solute-membrane interactions) and solute speciation (solute-solute interactions). Complexation of manganese and HA (solute-solute interactions) occurred at alkaline conditions but did not enhance manganese retention. At high pH manganese precipitated as solid MnCO3 and these precipitates achieved high retention (99%), even without the presence of HA. ES retention by NF membrane was controlled by size exclusion (solute-membrane interactions). For the tighter TFC-SR3, whose pore size are smaller than the size of ES, ES retention increased in the presence of HA, while for the looser TFC-SR2, whose pores are bigger than ES diameter, ES retention decreased in the presence of HA. For TFC-SR3 increase of ES retention in the presence of HA was due to size exclusion (solute-membrane interactions) and formation of ES-HA complexes (solute-solute interactions). For TFC-SR2 HA-membrane interactions were dominant with respect to solute-solute interactions, increasing membrane molecular weight cut-off (MWCO) and in turn passage of ES. The influence of pressure (5-15 bar) on ES retention in the presence of HA was systematically investigated. Results showed that ES transport through TFC-SR2 and TFC-SR3 was dominated by convection. For the tighter TFC-SR3 lower permeate flux was responsible for the increase of retention with pressure, while for the looser TFC-SR2 higher permeate flux increased concentration polarisation, decreasing retention with pressure. The presence of HA lowered the permeate flux, resulting in a less pronounced variation of retention with pressure for TFC-SR2 and in constant retention for TFC-SR3. The impact of manganese scaling on the performance of NF membranes was investigated at neutral pH. The effects of inorganic precipitates on flux and solute retention by NF have been so far scarcely studied and the impact of inorganic scaling on micropollutant retention by NF is unknown. Findings from this research indicated that manganese deposits did not foul the membranes but on the contrary enhanced their flux and prevented fouling by HA and Ca. The retention of ES, manganese and HA by membranes through which manganese was previously filtered was found to decrease with respect to solute retention by virgin membranes. Manganese filtration was shown to increase membrane MWCO and hydrophilicity. It was proposed that manganese-membrane interactions caused swelling of the membrane active layer by increasing the membrane free volume. The findings of this research indicated the importance of investigating simultaneously the impacts of solute-solute interactions and solute-membrane interactions to understand and explain transport and removal mechanisms of organic and inorganic contaminants by NF.
6
Choudhury, Ankan. "Physico-chemical investigation of solute-solute, solute-solvent and solvent-solvent interactions of some compounds in non-aqueous and mixed solvent media." Thesis, Th 541.34:C552p, 2005. http://hdl.handle.net/123456789/704.
Full text
7
Harrison, John. "Climatic variation, solute concentration and solute flux in meltwaters draining from an alpine glacier." Thesis, University of Salford, 2006. http://usir.salford.ac.uk/42976/.
Full textAbstract:
Cationic denudation rates in glacierised basins are considerably higher than the global mean. High specific discharge coupled with rapid dissolution of finely-divided sediment produced by glacial erosion results in high solute flux levels in rivers draining glacierised basins. As solute cc concentration varies inversely with discharge, variation with discharge of solute flux, the product of discharge and solute concentration, relates to the extent to which changes in volume of flow offset changes of concentration. Since the 1970s, in the European Alps, warming air temperatures have resulted in increases in discharge from glacierised catchments.
8
Shepherd, W. J. "Solute mixing in CSO structures." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251253.
Full text
9
Zhang, Le. "Neutral solute transport in cartilage." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 165 p, 2008. http://proquest.umi.com/pqdweb?did=1601524361&sid=8&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full text
10
Lekholm, Emilia. "Solute Carriers in Metabolism : Regulation of known and putative solute carriers in the central nervous system." Doctoral thesis, Uppsala universitet, Funktionell farmakologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-331328.
Full textAbstract:
Solute carriers (SLCs) are membrane-bound transporter proteins, important for nutrient, ion, drug and metabolite transport across membranes. A quarter of the human genome codes for membrane-bound proteins, and SLCs make up the largest group of transporter proteins. Due to their ability to transport a large repertoire of substances across, not just the plasma membrane, but also the membrane of internal organelles, they hold a key position in maintaining homeostasis affecting metabolic pathways. Unfortunately, some of the more than 400 identified SLCs are still not fully characterized, even though a quarter of these are associated with human disease. In addition, there are about 30 membrane-bound proteins with strong resemblance to SLCs, of which very little is known. The aim of this thesis is to characterize some of these putative SLCs, focusing on their localization and function in the central nervous system. Since many of the known SLCs play a vital part in metabolism and related pathways, the response to different nutritional conditions has been used as a key method. MFSD14A and MFSD14B, characterized in Paper I, are putative SLCs belonging to the Major Facilitator Superfamily (MFS) and found to be neuronal, differentially expressed in the mouse central nervous system and transiently upregulated in mouse embryonic cortex cultures due to amino acid deprivation. They were also altered in areas of the mouse brain after starvation as well as after high fat diet. In Paper II, the effect on gene regulation due to complete amino acid starvation was monitored in a mouse hypothalamic cell line and 47 different genes belonging to SLCs, or putative SLCs, were found to be affected. Of these, 15 genes belonged to already known amino acid transporters, whereas 32 were putative SLCs with no known function or SLCs not known to react to amino acids. The three SV2 proteins, SV2A, SV2B and SV2C, were studied in Paper III using human neuroblastoma cell lines. The high metabolic state of cancers often result in an upregulation and alteration of transporter proteins, and alterations of the SV2 proteins were found following different treatments performed in this study. Paper IV focused on putative SLCs of MFS type and their role in glucose metabolism. Mouse embryonic cortex cultures were subjected to glucose starvation and the gene expression of 19 putative transporters were analyzed. All but four of the putative transporters were affected either at 3h or 12h of glucose deprivation. In conclusion, several SLCs and putative SLCs studied in this thesis are strongly affected by alteration in metabolism, either due to amino acids or glucose or both. This makes the putative SLCs dynamic membrane-bound proteins, possibly transporters, highly affected by nutritional status and most likely regulated to maintain homeostasis.
11
An, Yili. "Solute transport in a heterogeneous field." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ30436.pdf.
Full text
12
Yang, Yang. "FIELD-SCALE WATER AND SOLUTE TRANSPORT." UKnowledge, 2014. http://uknowledge.uky.edu/pss_etds/37.
Full textAbstract:
Spatial variability of soil properties complicates the understanding of water and solute transport at the field scale. This study evaluated the impact of land use, soil surface roughness, and rainfall characteristics on water transport and Br- leaching under field conditions by means of a new experimental design employing scale-dependent treatment distribution. On a transect with two land use systems, i.e., cropland and grassland, rainfall intensity and the time delay between Br- application and subsequent rainfall were arranged in a periodically repetitive pattern at two different scales. Both scales were distinct from the scale of surface roughness as described by elevation variance. Nests of tensiometers and suction probes were installed at 1-m intervals along the transect to monitor matric potentials and Br- concentrations at different depths, respectively. After rainfall simulation, soil samples were collected at every 0.5 m horizontal distance in 10 cm vertical increments down to 1 m depth for Br- analysis. Soil Br- concentration was more evenly distributed with soil depth and leached deeper in grassland than cropland, owing to vertically continuous macropores that supported preferential flow. Frequency-domain analysis and autoregressive state-space approach revealed that the dominant factors controlling Br- leaching varied with depth. In shallow layers, land use was the main driving force for Br- distribution. Beyond that, the spatial pattern of Br- was mostly affected by rainfall characteristics. Below 40 cm, the horizontal distribution of Br- was dominated by soil texture and to a smaller extent by rainfall intensity. Bromide concentrations obtained from soil solution samples that were collected through suction probes showed similar results with respect to the influence of rainfall intensity. The spatial variation scale of temporal matric potential change varied with both time and depth, corresponding to different boundary condition scales. Matric potential change in some cases, reflected the impact of soil properties other than the boundary conditions investigated, such as hydraulic conductivity, contributing to the scale-variant behavior of Br- leaching. These findings suggest the applicability of scale-dependent treatment distribution in designing field experiments and also hold important implications for agricultural management and hydrological modelling.
13
Moores, Andrew. "Solute mixing in open channel flow." Thesis, Heriot-Watt University, 1996. http://hdl.handle.net/10399/686.
Full text
14
Visudmedanukul, Punlop. "Solute Transport Through Cement-Bentonite Barriers." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/123466.
Full text
15
Jimoh, Moduple O. "Solute mixing due to square manholes." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/77149/.
Full textAbstract:
Dispersion in sewers affects the concentration of pollutants within urban drainage systems and the quest to understand it has led to extensive studies of the hydraulics within circular manholes. Since there are both circular and square manholes within the urban drainage system, it is important to understand the hydraulics within a square manhole, its similarities and/or differences. This research is aimed at describing the transportation and mixing of soluble pollutants through urban drainage systems and the effects of structures such as manholes. It also seeks to study the relationship between headloss and dispersion coefficient in a full flowing pipe. Laboratory solute transport studies were carried out on a straight pipe with two diameter sizes (35 mm and 25 mm) of orifice plate inserted. Two square manhole sizes (388 mm x 388 mm and 150 mm x 150 mm) with a straight through flow was also studied at surcharge and overflow conditions. A relationship between the total headloss along the length of the pipe and the dispersion coefficient was established. With the introduction of a new parameter, a relationship was also established between the headloss due to the orifice and the dispersion coefficient when an orifice plate is inserted along the line of flow. It was observed for the large manhole size that at low surcharge depths there was more mixing occurring while at high surcharge depths the dye travels in a straight jet with some tracer trapped at the upper manhole volume. There exists a transition zone between the low and high surcharge depths which is not evident in the small size manhole. These observations mirror the phenomena that have already been observed in circular manholes. Manhole overflow studies was indicative of a completely mixed flow for the large manhole whereas for the small manhole it suggests a piston flow (sometimes referred to as plug flow) with some longitudinal dispersion occurring.
16
Nilsson, Kristina. "Solute exchange across the alveolo-capillary barrier." Lund : Depts. of Clinical Physiology, Malmö University Hospital and Lund University Hospital, Lund University, 1997. http://books.google.com/books?id=A0hrAAAAMAAJ.
Full text
17
Kurosawa, Izumi. "Solid-Liquid Equilibrium in Multi Solute Systems." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4993.
Full textAbstract:
Solid-liquid equilibrium in isomorphous amino acid systems has been investigated as a model for systems that form solid solutions. Solid- and liquid-phase compositions in L-valine + L-leucine, L-valine + L-isoleucine, and L-isoleucine + L-valine in water were measured over the entire range of solid composition, and it was shown (from mass balance and phase rule considerations) that these systems form solid solutions. The solid- phases resulting from isothermal and cooling crystallization experiments were also investigated using powder x-ray diffractometry which showed that homogeneous solid solutions could only be obtained in cooling crystallization experiments, whereas isothermal experiments generally produced inhomogeneous solids. This suggests that data reported in the literature from isothermal experiments may not represent true equilibrium values. Solid-phase activity coefficients were estimated using binary and ternary equilibrium data and the UNIFAC-Kuramochi model for liquid-phase nonidealities. The solid phases in the three systems investigated exhibited significant nonidealities that were correlated using the Margules model. The model parameters exhibited a linear relationship with the ratio of binary solubilities of the two solutes. Such simple relationship may be advantageous when solid-liquid equilibrium of thermally unstable solutes or components with unknown physical properties are crystallized.
18
Ladha, Nuruddin B. "Modeling solute transport in soils from Ataratiri." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0007/MQ45524.pdf.
Full text
19
Ivanov, Rosen. "Solute clustering in multi-component aluminium alloys." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI012/document.
Full textAbstract:
La décomposition de solutions solides sursaturées d'alliages multiconstitués Al-Cu- (Li, Mg) pose des défis théoriques et expérimentaux. La formation de fluctuations chimiques à température ambiante est analysée de façon critique en utilisant une combinaison de diffusion centrale (SAS), de calorimétrie différentielle à balayage (DSC), de sonde atomique tomographique (APT) et de micro-dureté. Une méthodologie pour l'interprétation combinée de données SAS d'expériences utilisant des neutrons et des rayons X est proposée et permet une comparaison avec les données de sonde atomique. Les résultats donnent la chimie et les dimensions sub-nanométriques des amas. L'effet du Mg sur les cinétiques de vieillissement naturel est discuté dans le contexte de son interaction avec les lacunes disponibles pour la diffusion. De courts traitements isothermes à températures relativement basses sont utilisés pour dissoudre les amas présents après vieillissement naturel et obtenir une solution solide avec moins de lacunes qu’après mise en solution. Lorsque du Mg est présent dans le système Al-Cu-Li, le soluté libéré après dissolution se regroupe avec une cinétique comparable à celle obtenue immédiatement après la trempe du traitement de mise en solution. L'augmentation immédiate de la cinétique de mise en amas quand une concentration quelconque de Mg est présente dans les alliages Al-Cu- (Li, Mg) est révélée avec couple de diffusionDecomposition of super saturated solid solutions of Al-Cu-(Li,Mg) alloys pose theoretical and experimental challenges. The chemical fluctuations - clusters - formed at room temperature are critically analysed using a combination of in-situ small angle scattering (SAS), differential scanning calorimetry (DSC), atom probe tomography (APT), and micro-hardness. A methodology for combined interpretation of SAS data from experiments using neutron and X-ray radiation is proposed and allows for comparison with standard analysis performed by APT. The results effectively capture the chemistry and sub-nanometer dimensions of clusters. The profound positive effect of Mg on clustering of Cu via excess vacancies available for diffusion is captured through the clustering kinetics over the course of natural ageing. Short isothermal treatments at relatively low temperatures are used to dissolve naturally aged clusters and obtain a solid solution with less expected vacancies. When Mg is present in the Al-Cu-Li system, released solute after dissolution exhibits clustering behaviour with kinetics comparable to those immediately after quench from solution treatment. The immediate increase of clustering kinetics when any concentration of Mg is present in Al-Cu-(Li,Mg) alloys is revealed through a composition graded sample
20
Gurung, Bhoj Bahadur. "Physico-chemical studies on the solute-solvent interactions of some electrolytes in various single and binary solvent media." Thesis, University of North Bengal, 2006. http://hdl.handle.net/123456789/747.
Full text
21
Bhola, Sumita. "Effects of solute polarization on the hydrodynamics within membrane-fluid-solute systems, with special application to hollow fiber bioreactors." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6716.
Full textAbstract:
The primary objective of this study was to assess the influence of osmotically active macromolecules on the hydrodynamics of hollow fiber membrane systems which, in turn, influences solute distributions within these bioreactors. This included verifying the phenomenon of concentration polarization of bovine serum albumin (BSA) in a rectilinear flow cell designed to incorporate the salient features of the hollow fiber bioreactor. Following characterization of the membrane used in the study, experimentally determined concentration profiles of BSA were compared with those predicted from theoretical analysis. The membrane characterization revealed local variability in the permeability of the membrane: L$\rm \sb{p}/\mu$ was found to vary between 2.80 $\times$ 10$\sp{-11}$ and 8.19 $\times$ 10$\sp{-11}$ m$\sp2$s/kg. The membrane permeability did not exhibit hysteresis effects due to pressure nor were there substantial changes in the permeability as a result of membrane aging. The permeability of the membrane decreased by approximately 30% following conditioning with a solution of BSA and was successful at retaining the protein. Transient BSA polarization was observed in the extra-luminal space of the rectilinear flow cell after 12, 24 and 36 hours of operation. The theoretical concentration profiles of BSA over predicted the experimental concentration profiles when assuming a membrane permeability equal to the average of the membrane coupon measurements. Further experiments consisted of examining possible dilution of the BSA samples obtained from the flow cell as well as investigating the theoretical assumption of a one-dimensional model. Sedimentation experiments showed that settling of the protein was not responsible for diluting the BSA samples. The local variability in the membrane permeability is thought to contribute to the discrepancy between the theoretical and experimental concentration profiles, as well as transverse concentration gradients not considered by the model. (Abstract shortened by UMI.)
22
Kettle, Helen Rosalind. "Modelling solute dispersion in natural channels using fuzzy exchanges." Thesis, Lancaster University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250615.
Full text
23
Mollee, Thomas. "Mathematical modelling of solute transport through stratum corneum /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18923.pdf.
Full text
24
Weinand, Martin. "Expressionsregulation von Transportern kompatibler Solute in Corynebacterium glutamicum." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972517790.
Full text
25
Zhao, Zhihong. "Stress Effects on Solute Transport in Fractured rocks." Doctoral thesis, KTH, Teknisk geologi och geofysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-42361.
Full textAbstract:
The effect of in-situ or redistributed stress on solute transport in fractured rocks is one of the major concerns for many subsurface engineering problems. However, it remains poorly understood due to the difficulties in experiments and numerical modeling. The main aim of this thesis is to systematically investigate the influences of stress on solute transport in fractured rocks, at scales of single fractures and fracture networks, respectively. For a single fracture embedded in a porous rock matrix, a closed-form solution was derived for modeling the coupled stress-flow-transport processes without considering damage on the fracture surfaces. Afterwards, a retardation coefficient model was developed to consider the influences of damage of the fracture surfaces during shear processes on the solute sorption. Integrated with particle mechanics models, a numerical procedure was proposed to investigate the effects of gouge generation and microcrack development in the damaged zones of fracture on the solute retardation in single fractures. The results show that fracture aperture changes have a significant influence on the solute concentration distribution and residence time. Under compression, the decreasing matrix porosity can slightly increase the solute concentration. The shear process can increase the solute retardation coefficient by offering more sorption surfaces in the fracture due to gouge generation, microcracking and gouge crushing. To study the stress effects on solute transport in fracture systems, a hybrid approach combing the discrete element method for stress-flow simulations and a particle tracking algorithm for solute transport was developed for two-dimensional irregular discrete fracture network models. Advection, hydrodynamic dispersion and matrix diffusion in single fractures were considered. The particle migration paths were tracked first by following the flowing fluid (advection), and then the hydrodynamic dispersion and matrix diffusion were considered using statistic methods. The numerical results show an important impact of stress on the solute transport, by changing the solute residence time, distribution and travel paths. The equivalent dispersion coefficient is scale dependent in an asymptotic or exponential form without stress applied or under isotropic compression conditions. Matrix diffusion plays a dominant role in solute transport when the hydraulic gradient is small. Outstanding issues and main scientific achievements are also discussed.QC 20111011
26
Turner, Adam Henry. "Investigations of ionic liquid-solute interactions towards applications." Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.713456.
Full text
27
Sattayakawee, Sarawut. "Glucosylglycerol : a compatible solute in Arthrospira (Spirulina) platensis." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555388.
Full textAbstract:
Glucosylglycerol was identified as the major compatible solute in Arthrospira (Spirulina) platensis LB 2340 and the accumulation of glucosylglycerol was dependent on external salt concentration. An alternative method of measuring glucosylglycerol content was developed using acid hydrolysis. Glycerol produced from the acid hydrolysis was a first order chemical reaction. The maximum glycerol concentration was calculated and converted to original glucosylglycerol concentration. The ggps gene, that encoded the enzyme GGPS (glucosylglycerol-phosphate synthase) in glucosylglycerol biosynthesis pathway, was successfully isolated from the A. platensis genome. The nucleotide sequence of 1509 bp and the translated amino acid sequence of 502 aa were determined. The protein sequence was identical to the GGPS amino acid sequence of Arthrospira maxima CS-328. Computer analysis of the isolated amino acid sequence revealed the possibility of positively charged amino acid residues involved in phosphate binding at the active site of GGPS enzyme. The expression of ggps gene was directly proportional to external salinity. The effect of external salinity on accumulation of glucosylglycerol showed the same correlation. The maximum concentration of glucosylglycerol accumulated intracellularly was 200.58 mM. The compatible solute acted as an enzyme stabiliser and in addition, 0.5 mM of exogenous glucosylglycerol (almost the same amount to the maximum intracellular concentration) showed a positive effect on growth and the rate of photosynthesis. Accumulation of exogenous glycine betaine and trehalose were studied in A. platensis cells, but they showed no significant effect. _________________________.
28
Jin, Hao. "Atomistic simulations of solute-interface interactions in iron." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/47037.
Full textAbstract:
The kinetics of the recrystallization and austenite-ferrite (fcc-bcc) phase transformation in steels are markedly affected by substitutional alloying elements. Nevertheless, the detailed mechanisms of their interaction with the grain boundaries and interfaces are not fully understood. Using density functional theory, we determine the segregation energies of commonly used alloying elements (e.g. Nb, Mo, Mn, Si, Cr, Ni) in the Σ5 (013) tilt grain boundary in bcc and fcc Fe, and the bcc-fcc interfaces. We find a strong interaction between large solutes (e.g. Nb, Mo and Ti) and grain boundaries or interfaces that is consistent with experimental observations of the effects of these alloying elements on delaying recrystallization and the austenite-to-ferrite transformation in low-carbon steels. In addition, we compute the solute-solute interactions as a function of solute pair distance in the grain boundaries and interfaces, which suggest co-segregation for these large solutes at intermediate distances in striking contrast to the bulk.
Besides the prediction of solute segregation, the self- and solute-diffusion in Fe-based system are also investigated within a framework combining density functional theory calculations and kinetic Monte Carlo simulations. Good agreement between our calculations and the measurements for self- and solute diffusion in bulk Fe is achieved. For the first time, the effective activation energies and diffusion coefficients for various solutes in the α-Fe Σ5 (013) grain boundary are determined. The results demonstrate that grain boundary diffusion is significantly faster than for lattice diffusion, confirming grain boundaries are fast diffusion paths. By contrast, the effective activation energy of self-diffusion in a bcc-fcc Fe interface is close to the value of fcc bulk self-diffusion, and the investigated bcc-fcc interface provides a moderate "fast diffusion" path.
29
Müller, Axel. "Structure and recognition in bacterial solute uptake receptors." Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434141.
Full text
30
Grimshaw, Paul Edward. "Electrical control of solute transport across polyelectrolyte membranes." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14425.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1989.Includes bibliographical references.
Supported in part by NSF ERC. CDR-8500003 Supported in part by NSF. CBT-8512814
by Paul E. Grimshaw.
Ph.D.
31
Chao, Jessica Jade. "Compatible Solute Binding to an Archaeal Inositol Monophosphatase." Thesis, Boston College, 2011. http://hdl.handle.net/2345/2216.
Full textAbstract:
Thesis advisor: Mary F. RobertsCrystallization studies in presence of organic osmolytes were conducted to better understand the specific mechanism of compatible solute binding to the inositol monophosphatase of Archaeoglobus fulgidus. The synthesis of a-diglycerol phosphate, one of the natural osmolytes of A. fulgidus, was also completed for kinetic testing of its I-1-Pase thermoprotective properties and for crystallization trials
Thesis (MS) — Boston College, 2011
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
32
Archipov, Ruslan, Aleksandar Cvetkovic, Frank Stallmach, and Adrie J. J. Straathof. "Anisotropic solute and solvent diffusion in protein crystals." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-196849.
Full text
33
Palmer, Donna Jade. "Solute effects on the properties of supercritical solutions." Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/29983.
Full textAbstract:
Supercritical (sc) fluids are extensively used for material processing and carbon dioxide is the most commonly used solvent. In these solutions, solute-solvent interactions consist primarily of Van der Waals forces and the small amount of data published shows that the solute has only a small effect on solution structure. The use of more polar solvents allows high concentrations of polar solutes to be dissolved resulting in more ordered solutions. This has an effect on clustering and mass transport. The aim of this thesis is to investigate solute-solute-solvent interactions in sc difluoromethane and to quantify the effect on solution viscosity for the first time. The local composition about the solvatochromic probe has been measured as a function of pressure and solute polarity and the Kamlet-Taft polarisability/dipolarity and hydrogen bond donor parameters determined. Variations in these solvent properties are understood in terms of solute aggregation and a model for solvation is proposed. The use of a piezoelectric quartz crystal as a reliable high-pressure viscometer is proposed and used to determine the viscosity of sc solutions as a function of pressure and solute polarity. A modification of the Dole-Jones equation is used to model the viscosity of simple sc solutions and the volume fraction of solute is shown to be the key factor affecting solution viscosity. Rapid expansion of supercritical solutions (RESS) is a technique used to reduce particle size and alter morphology of pharmaceuticals. As with most sc processes carbon dioxide has been the solvent of choice, but many pharmaceuticals are polar compounds or salts, which suffer from low solubility. Here the applicability of sc difluoromethane for precipitation of materials by RESS is presented.
34
Archipov, Ruslan, Aleksandar Cvetkovic, Frank Stallmach, and Adrie J. J. Straathof. "Anisotropic solute and solvent diffusion in protein crystals." Diffusion fundamentals 2 (2005) 116, S. 1-2, 2005. https://ul.qucosa.de/id/qucosa%3A14456.
Full text
35
Bekki, Slimane. "Contribution a l'etude de l'effet marangoni de solute." Paris 6, 1988. http://www.theses.fr/1988PA06A009.
Full text
36
Bigard, Antoine. "Varietal differences in solute accumulation and grape development." Thesis, Montpellier, SupAgro, 2018. http://www.theses.fr/2018NSAM0063.
Full textAbstract:
Jusqu'à récemment, les variétés destinées à la production de vin (majoritairement V. vinifera) ont été sélectionnées pour forte accumulation en sucres et composés du métabolisme secondaire (arômes, tanins, anthocyanes). Certains paramètres du changement climatique (températures, CO2) accentuent la tendance à l'augmentation des teneurs en sucres à la récolte donnant des vins plus alcooleux. L'augmentation de la teneur en alcool des vins est un phénomène planétaire, avec des augmentations annuelles de 0,16%. Cela altérant le profil qualitatif notamment en impactant l'équilibre alcool/acidité et pose un problème vis-à-vis de la santé des consommateurs.Le raisin est un fruit pulpeux non-climactérique se développant en deux phases. La première est la phase herbacée durant laquelle s’accumule majoritairement les acides maliques et tartriques. Durant cette phase, la baie grossit par mitose et expansion vacuolaire. La deuxième phase de croissance est associée à l'importation massive d'hexoses, d’eau et de potassium. A la fin de la deuxième phase de croissance, le phloème arrête son déchargement et la baie concentre ses principaux métabolites par évaporation. Certaines pratiques œnologiques permettent de réduire les teneurs en sucres des moûts ou en alcool des vins (CEE-606/2009 et CEE-53/2011), mais sont partielles ou coûteuses et peuvent impacter la qualité des vins. Les pratiques culturales ne modifient pas suffisamment le développement du raisin pour être efficaces, sauf à dégrader le potentiel qualitatif de la vendange. Sur le long terme, l'approche la plus prometteuse est la sélection variétale.Ce dernier aspect fut abordé dans le projet de thèse. En premier lieu, de nouvelles stratégies/outils de phénotypage permettant la caractérisation du développement du raisin furent développés. Ensuite, la diversité pour l'accumulation des métabolites primaires dans le raisin (V. vinifera) ou pouvant être généré par croisement avec la microvigne fut analysée. Dans un dernier volet, la caractérisation physiologique de génotypes issus d’un croisement entre V. vinifera et M. rotundifolia présentant un caractère de faible accumulation en sucres durant la maturation des raisins fut approfondie.Les résultats principaux de ce travail indiquent :1) Il est possible d’apprécier le développement d'une population de baies tant en asynchronie (bains densimétriques) qu’en hétérogénéité (Dyostem). La couleur du fruit n’était pas un bon indicateur du début de la maturation, apparaissant 1 à 5 jours après les premier signes de ramollissement des baies. Par ailleurs, les suivis réalisés à l'échelle de population de baies ont montré que pour des analyses fines, il était préférable d’analyser le fruit unique.2) Il existe une grande diversité chez V. vinifera pour ce qui concerne la compositions en métabolites primaires des baies et leurs dilutions. La possibilité de ségréger indépendamment l'accumulation d'eau, des sucres, des acides et des cations fut révélée, ouvrant d’intéressantes perspectives en termes d'innovation variétale.3) L’analyse du caractère faible teneur en sucres chez des descendants de V. vinifera et M. rotundifolia montre que ce caractère ne résulte ni d’une limitation ou d'un décalage de l'accumulation, ni d’une plus grande hétérogénéité/asynchronie des baies. Les résultats suggèrent qu'il existe des différences mécanistiques entre niveau de croissance et pression osmotique du fruit lors de la maturation entre génotypes. Cette découverte soulève de nombreuses questions : existe-t-il des différences dans les structures des parois cellulaires ou de leurs enzymes associées ? Est-ce que les cellules des baies des génotypes à faible teneur en sucres sont plus grosses ou plus nombreuses que les variétés traditionnelles ?Deux de ces descendants ont été croisés avec la microvigne pour détecter les QTLs associés à ce caractère dans l'objectif d'identifier les fonctions contrôlant ce trait d'intérêt agronomiqueUntil recently, varieties used for wine production (mainly V. vinifera) have been selected for high sugar accumulation and secondary metabolism compounds (aromas, tannins, anthocyanins). Some climate change parameters (temperatures, CO2) accentuate the trend towards higher sugar levels at harvest, resulting in more alcoholic wines. The increase in wine alcohol content is a global phenomenon, with annual increases of 0.16%. This alters the qualitative profile, in particular by impacting the alcohol/acidity balance and poses a problem for consumer health.The grape is a non-climacteric fleshy fruit that develops in two phases. The first is the herbaceous phase during which malic and tartaric acids accumulate mainly accumulate. During this phase, the berry grows by mitosis and vacuolar expansion. The second phase of growth is associated with the massive import of hexoses, water and potassium. At the end of the second growth phase, the phloem stops unloading and the berry concentrates its main metabolites by evaporation. Some oenological practices make it possible to reduce the sugar content of must or alcohol wines content (CEE-606/2009 and CEE-53/2011), but are partial or costly and can have an impact on the wines quality. Cultivation practices do not sufficiently modify the development of the grape to be effective, except that they degrade the quality potential of the harvest. In the long term, the most promising approach is the variety selection.The latter aspect was addressed in the thesis project. First, new phenotyping strategies/tools were developed to characterize grape development. Then, the diversity for the accumulation of primary metabolites in grapes (V. vinifera) or that can be generated by crossing with the microvine was analysed. In the last part, the physiological characterisation of genotypes resulting from a cross between V. vinifera and M. rotundifolia with a low sugar accumulation character during grape ripening was further developed.The main results of this work indicate:1) It is possible to assess the development of a berries population both in asynchrony (densimetric baths) and in heterogeneity (Dyostem). The colour of the fruit was not a good indicator of the beginning of ripening, appearing 1 to 5 days after the first signs of berry softening. In addition, monitoring at the berry population level has shown that for fine analyses, it is preferable to analyse the single fruit.2) There is a great diversity in V. vinifera with regard to the composition of primary berry metabolites and their dilutions. The possibility of independently segregating the accumulation of water, sugars, acids and cations was revealed, opening up interesting prospects for varietal innovation.3) Analysis of the low sugar concentration trait in descendants of V. vinifera and M. rotundifolia shows that this characteristic does not result from a limitation or delay in accumulation or from greater heterogeneity/asynchrony of the berries. The results suggest that there are mechanistic differences between growth level and osmotic pressure of the fruit during maturation between genotypes. This discovery raises many questions: are there differences in the cell wall structures or their associated enzymes? Are berry cells of low sugar genotypes larger or more numerous than traditional varieties?Two of these descendants were crossed with the microvine to detect the associated QTLs to this trait in order to identify the functions controlling this agronomic interest trait
37
HU, XUEZHENG. "Contribution a l'etude de l'effet marangoni de solute." Paris 6, 1992. http://www.theses.fr/1992PA066186.
Full textAbstract:
Ce travail est consacre a l'etude d'un effet marangoni de solute ou les gradients de tension interfaciale sont crees par le desequilibre de partage d'un solute tensioactif entre deux phases liquides partiellement miscibles qui se trouvent en etat de saturation mutuelle incomplete. L'equilibre thermodynamique d'un tel systeme est caracterise par l'equilibre de partage du solute et l'equilibre ternaire des constituants de chacune des deux phases liquides. Au cours du retour a l'equilibre il se produit un transfert du surfactant au travers l'interface couple a une dissolution mutuelle des deux solvants. Nous avons etudie comment un tel equilibre thermodynamique pouvait etre restaure en observant les mouvements d'une lentille organique (nitroethane ou decane) deposee a la surface d'une solution aqueuse tensioactive avec des tensioactifs a longue chaine (bromure de dodecyltrimethylammonium) ou a courtes chaines (n-alcools avec n=4 ou 5) presentant differentes cinetiques de transfert interfacial couplees lineairement ou non avec la dissolution mutuelle des solvants. Des effets hydrodynamiques spectaculaires sur le mouvement de la lentille sont alors observes et interpretes
38
Bekki, Slimane. "Contribution à l'étude de l'effet Marangoni de solute." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37611678d.
Full text
39
Stouffer, Melissa Ann. "A study of organogels and their solute interactions." Winston-Salem, NC : Wake Forest University, 2009. http://dspace.zsr.wfu.edu/jspui/handle/10339/42499.
Full text
40
Mitchell, Gordon. "Aspects of solute movement in the British uplands." Thesis, University of Leeds, 1991. http://etheses.whiterose.ac.uk/476/.
Full textAbstract:
The aim of this research is to determine the process by which runoff draining parts of the UK uplands becomes discoloured. Recent increases in colour are perceived as a problem due to the frequency with which EC surface water directives are breached, to the increased cost of meeting standards, to an increase in consumer complaints, and due to the possible deleterious health effects of consuming coloured potable water. The work was conducted over the last four years, largely in the Upper Burn and Nidd valleys, north Yorkshire, and at the University of Leeds. Existing knowledge on the chemical nature and environmental genesis of coloured water is reviewed, and related to the chemical nature of coloured waters examined in this study. Analysis of water quality archives and direct monitoring of selected catchments was conducted enabling the spatial and temporal distribution of coloured waters to be determined. A tentative process theory was produced, and tested by controlled laboratory investigations. Coloured runoff is derived from Winter Hill soil, raw acid oligo-fibrous peat, and is most intense from areas with slopes < 5% and high drainage densities. The seasonal pattern of colour is highly regular, and is a product of rainfall and soil moisture deficit. Colour is strongly associated with discharge, and demonstrates the operation of a catchment flushing mechanism. Runoff is discoloured in a three phase process; colour production, solubilisation and removal. Colour is a product of organic decomposition, dependent upon microbiological activity, moisture deficit, temperature and peat structure. Solubilisation of colour is dependent upon solution pH, temperature, the chemical structure of organic molecules and the availability of iron. The removal of decomposition products, as colour, is strongly dependent on the moisture status of peat, and its ability to rewet after drying. The implications of these findings for future colour levels and for catchment and catchwater management are discussed.
41
Kunisu, Masahiro. "Structure and function of solute atoms in ZnO." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/143976.
Full text
42
Haider, Muhammad Rezaul. "Longitudinal Thermal and Solute Dynamics in Regulated Rivers." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6870.
Full textAbstract:
Dam releases increase river stage and can reverse groundwater movement into and out of the river. As the flood, thermal, and solute waves travel downstream in a regulated river, the size of the waves is anticipated to be affected both by river processes and exchanges with near river groundwater. This study established a modeling framework to quantify the influences of the groundwater exchanges on the temperatures and solute concentration dynamics along regulated rivers. The wave properties, volume of exchanges, conservative solute mass exchanges, and heat energy exchanges were calculated as a function of time and distance downstream. Results show that the temperature and solute concentrations are influenced by the arrival of flood waves. Groundwater exchanges were found to affect temperatures along the river with a minimal effect on solute concentration. These findings provide insight regarding the influences of hydropeaking occurring in a large fraction of rivers in the world which has important implications for water quality and the ecology of regulated rivers.
43
Shams, Tahiatul. "Solute Carrier Transporters in drug-drug/herb interactions and their molecular regulation in disease." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/20342.
Full textAbstract:
Solute Carrier Transporters (SLCs) are a group of influx transporters responsible for the cellular uptake of endogenous substances and exogenous molecules including a number of clinically important drugs. They are widely expressed in epithelium throughout the body, where they play essential roles in determining the disposition and elimination of these substances. They have been recognized as the crucial determinants to drug pharmacokinetics in humans. The dysfunction of SLC transporters contributes to the pathophysiology of several diseases, as well as largely impacts on drug pharmacokinetic performance, which in turn alters drug efficacy and toxicity. SLCs can also mediate the transport of various herbal compounds and dietary substances. Due to the wide substrate specificity of SLC transporters there is a possibility of potential drug-drug, drug-herb or drug-food interactions that might compromise therapeutic outcomes. Therefore, understanding the structure, expression, function and molecular regulation of SLCs is required to optimise therapeutic outcomes and drug development. The studies presented in this thesis were aimed to explore the physiological and pharmacological role of SLCs, understand the mechanisms through which drug-drug/herb interactions may occur and study the potential molecular regulation of the function and expression of SLCs. The inhibitory effects of five clinically relevant alkaloids were investigated using HEK293 cell line over-expressing essential SLCs. The study indicated that, tryptanthrin significantly inhibited the transport activity of OAT3, whereas, chelerythrine acted as a potent inhibitor of OATP1A2, OCT1 and OCT2. The inhibitory effects of these two natural alkaloids suggested the potential interactions of tryptanthrin and chelerythrine with OAT3, OATP1A2 and OCTs drug substrates, leading to altered pharmacokinetic profiles of these drugs. Therefore, precautions are warranted on the coadministration of these compounds with OAT3, OATP1A2 or OCT substrates due to unexpected toxicity or undesirable therapeutic outcomes. In the second study, we reported that Wnt/β-catenin pathway is involved in the molecular regulation of OATP1A2 function and expression. Transporter functional assays showed that OATP1A2 transport activity was impaired when cells were treated with Wnt-specific inhibitors FH535, 21H7; Wnt specific activator HLY78 and Wnt agonist. Treatment with FH535 reduced the transport activity of OATP1A2 by decreasing the apparent affinity of OATP1A2 for its substrate (Km), without changing the Vmax. On the other hand, 21H7, HLY78 and Wnt agonist treatments showed a reduced Vmax of E3S transport by OATP1A2, without affecting the affinity of the transporter for its substrate (Km). Immunoblotting analysis showed that 21H7, HLY78 and Wnt agonist significantly impaired the plasma membrane expression of OATP1A2. In addition, OATP1A2 overexpressing HEK293T cells co-transfected with β-catenin silencing siRNA showed significant reduction in OATP1A2 function as well as cell surface expression. Overall, Wnt modulators down-regulated the function and cell surface expression of OATP1A2, which can potentially impact the disposition of drugs that are transported by this transporter. In the third study we found that Wnt pathway is also involved in the regulation of OATs. Transporter functional assays showed that Wnt inhibitors FH535 and 21H7 reduced the transport activity of OAT1. FH535 also impaired the function of OAT4. The Wnt inhibitors did not affect the total cell and plasma membrane expression of OAT1 and OAT4. The transport function of OAT3 was impaired by Wnt-specific modulators FH535, 21H7 and HLY78. Kinetic analysis suggested that the impaired transport activity of OAT3 following FH535 treatment was due to the decreased Vmax for substrate transport, while the apparent affinity remained unchanged. FH535 treatment decreased the plasma membrane expression of OAT3. Therefore, modulation of OAT function by Wnt pathway might impact the pharmacokinetics of its drug substrates. Finally, an update on the interactions of anticancer drugs with OATPs has been discussed in chapter 5. OATPs play an important role in the disposition of anticancer drugs. Modulation of OATPs function and expression by genetic polymorphism and drug-drug/herb interactions significantly impacts the PK of anticancer drugs. Because of their abundant expression in various tumour cells and their ability to transport numerous anticancer drugs, OATPs can be considered as important therapeutic targets in anticancer drug design. Due to their physiological and pharmacological importance, SLC transporters play a significant role in human health and disease. Further research on SLC transporters is necessary to comprehensively understand their involvement in human diseases and drug development.
44
Bian, Aiguo. "On the solute transport in an aquifer-aquitard system." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1319.
Full text
45
Waldner, Peter Andreas. "Water and solute release from a subalpine snow cover /." [Zürich] : [s.n.], 2002. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=14684.
Full text
46
Yasensky, David. "Solute-driven melting kinetics in the Sn-Bi system." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015847.
Full text
47
Kantola, A. M. (Anu M. ). "Liquid crystal NMR: director dynamics and small solute molecules." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514260704.
Full textAbstract:
Abstract
The subjects of this thesis are the dynamics of liquid crystals in external electric and magnetic fields as well as the magnetic properties of small molecules, both studied by liquid crystal nuclear magnetic resonance (LC NMR) spectroscopy. Director dynamics of a liquid crystal 5CB in external magnetic and electric fields was studied by deuterium NMR and spectral simulations. A new theory was developed to explain the peculiar oscillations observed in the experimental spectra collected during fast director rotation. A spectral simulation program based on this new theory was developed and the outcome of the simulations was compared with the experimental results to verify the tenability of the theory.
In the studies on the properties of small solute molecules, LC NMR was utilised to obtain information about anisotropic nuclear magnetic interaction tensors. The nuclear magnetic shielding tensor was studied in methyl halides, the spin-spin coupling tensor in methyl mercury halides and the quadrupolar coupling tensor in deuterated benzenes. The effects of small-amplitude molecular motions and solvent interactions on the obtained parameters were considered in each case. Finally, the experimental results were compared to the corresponding computational NMR parameters calculated in parallel with the experimental work.
48
van, den Daele Gerd Frans Agnes. "Investigation of flow and solute transport through unsaturated chalk." Thesis, University College London (University of London), 2005. http://discovery.ucl.ac.uk/1446785/.
Full textAbstract:
The Chalk is a fractured rock with a fine-grained porous matrix, where the matrix provides most of the porosity and storage capacity and the fractures greatly enhance the permeability. For the unsaturated zone, the role of the fractures and the matrix in flow and solute transport is not well understood. Therefore a tracer test was carried out in the unsaturated chalk at the Fleam Dyke research site in Cambridgeshire. The experiment, under natural rainfall conditions, involved distributing deuterium and bromide on a grass-covered lysimeter (a cube of volume 125 m3) and on an adjacent 4x4 m plot. Up until 15 months after the tracer application, none of the tracer was detected in the lysimeter drainage at 5 m depth. Repeated core profiles on the adjacent plot revealed significant differences in vertical tracer distribution, indicating lateral heterogeneity of transport pathways. The results of the tracer test were modelled with MACRO 5.0, a numerical dual permeability model that was initially developed for macroporous soils. The model suggested that fracture flow is important at the site, but that it is only initiated below a depth of about 1 m. The extent of fracture flow appeared to be highly variable in different layers of the profile, mainly depending on the saturated hydraulic conductivity of the matrix. Regarding exchange of solutes between the fractures and the matrix, the model indicated that advective exchange could be important and might even outweigh diffusive exchange. The results suggested that the Chalk aquifer at the Fleam Dyke site was only moderately vulnerable to pollution, but it was concluded that even for moderate rainfall conditions some bypass flow was possible. When modelling recharge without solute transport, it was shown that a simple water balance model called DFIDGWR could perform similar or better than MACRO 5.0.
49
Fallow, David James. "Time dependent adsorbing-desorbing solute transport in porous media." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0020/NQ47390.pdf.
Full text
50
Lee, Jangguen. "Experimental and numerical investigation of consolidation-induced solute transport." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1190048627.
Full text