in English This thesis deals with the legal regime of land-related waters. The initial part of the thesis explores relations pertaining to water and land. The main part of the thesis concentrates on legal aspects of land-related waters, powers of watercourse managers in respekt of such land and the legal regime of land connected with water structures, with an emphasis placed on the current legislative aspects of ponds and wells. Furthermore, the thesis deals with the general water protection in respect of land, in particular with water-resource protection zones and vulnerable areas. The last part of the thesis is dedicated to land-related issues of anti-flood protection, especially to limitations applicable to owners of property in flood zones.

In this work the method of isotopic substitution in neutron diffraction is used to measure the partial structure factors of several binary systems. Molten sodium chloride at 820(5) °C is investigated and an improvement is made on the previously available data. The applicability of a simple model pair potential for the asymptotic decay of the pair correlation functions is discussed. The glass forming system zinc chloride is also investigated in both the molten phase at 332(5) °C and the glassy phase at 25(1) °C. The measured partial pair distribution functions show that the zinc atoms are fourfold coordinated in both the glass and the liquid and that the first sharp diffraction peak in the total structure factor is mainly due to the zinc-zinc correlations. A simple ionic model can account for several factors associated with the ultimate decay of the partial pair correlation functions.

In this thesis, we report on our studies of water dynamics and structure in various biological environments which include: the surfaces of proteins and various oligosaccharides, the intervening space between proteins; and in the vicinity of cryoprotectant disaccharides in the liquid and ice phases. From a theoretical perspective, we propose methodology to compute diffusivity and residence times on the surface of biomolecules. In particular our proposed algorithm to compute residence times appears to be better in dealing with poor statistics associated with the number of water molecules that remain on a surfaces for extended times. The type of linkage between monomers and the anomeric configuration all play a major role in determining the structure and dynamics of water on the surface of carbohydrates.

Langmuir monolayers can be employed as simple model systems to study interactions at surfaces. Such investigations are important to fields ranging from biology to materials science. Herein, several aspects of these films and their associated water structure have been examined with vibrational sum frequency spectroscopy (VSFS). This second order nonlinear optical spectroscopy is particularly well suited for simultaneous investigations of the monolayer and the associated water structure with unprecedented surface specificity. The structures of these systems were altered through the control of experimental parameters including monolayer pressure, subphase temperature, pH and ionic content. Thermodynamic information about structural changes in a fatty amine monolayer's hydrophobic region was obtained by observation of the pressure and temperature dependence of the monolayer's solid to liquid phase transition. Further studies used the coordination of divalent cations to acid monolayers to perturb the water layers nearest to the film which enabled a better understanding of the water related VSFS features from these hydrophilic interfaces. Information from both the monolayer and water structure was then combined in order to examine the role of water in mediating ion-biomaterial interactions, often expressed in terms of the Hofmeister series.

Langmuir monolayers can be employed as simple model systems to study interactions at surfaces. Such investigations are important to fields ranging from biology to materials science. Herein, several aspects of these films and their associated water structure have been examined with vibrational sum frequency spectroscopy (VSFS). This second order nonlinear optical spectroscopy is particularly well suited for simultaneous investigations of the monolayer and the associated water structure with unprecedented surface specificity. The structures of these systems were altered through the control of experimental parameters including monolayer pressure, subphase temperature, pH and ionic content. Thermodynamic information about structural changes in a fatty amine monolayer's hydrophobic region was obtained by observation of the pressure and temperature dependence of the monolayer's solid to liquid phase transition. Further studies used the coordination of divalent cations to acid monolayers to perturb the water layers nearest to the film which enabled a better understanding of the water related VSFS features from these hydrophilic interfaces. Information from both the monolayer and water structure was then combined in order to examine the role of water in mediating ion-biomaterial interactions, often expressed in terms of the Hofmeister series.

It is well known that water molecules at room temperature tend to form ‘iceberg’ structures around the hydrocarbon chains of surfactant molecules dissolved in water. The entropy reduction (times the absolute temperature T) associated with the iceberg structure can be considered as the net driving force for self-assembly. More recently, many investigators measured long-range attractive forces between hydrophobic surfaces, which are likely to result from structuring of the water molecules in the vicinity of the hydrophobic surfaces. Similarly, the hydrophobic nature of most gas hydrate formers may induce ordering of water molecules in the vicinity of dissolved solutes. In the present work, the surface forces between thiolated gold surfaces have been measured using an atomic force microscope (AFM) to obtain information on the structure of the thin films of water between hydrophobic surfaces. The results have been used to develop a new concept for the formation of gas hydrates.

No / This paper aims to establish the acid concentration of finely dispersed droplets in hydrocarbon oils. Small quantities of aqueous sulphuric acid (H2SO4) were found to be trapped within hydrocarbon shells, making them inaccessible for concentration evaluation by titration. Fourier transform infrared spectroscopy (FTIR) used in the attenuated total reflection mode (ATR; FTIR-ATR) was applied to study the reaction products of squalane, C30H62, and an API Group I base oil with various concentrations of aqueous H2SO4. The absorbance comparison usually used for estimating acid concentrations was found to fail when small quantities of acid are trapped in the reaction product. It was found that the peak shift and changes in absorbance found for various pure aqueous acid concentrations were useful to establish the remaining concentration of the trapped H2SO4. This paper fulfils the identified need to study acid dissociation-dependent peak shifts of H2SO4 to find the acid concentration of finely dispersed droplets in hydrocarbon oils.

In 1982, Israelachvili and Pashley reported the first measurements of a hitherto unknown attractive force between two mica surfaces hydrophobized in cetyltrimethylammonium bromide (CTAB) solutions. Follow-up experiments conducted by many investigators confirmed their results, while others suggested that the "hydrophobic force" is an artifact due to nanobubbles (or cavitation). Evidences for the latter included the discontinuities (or steps) in the force versus distance curves and the pancake-shaped nano-bubbles seen in atomic force microscopic (AFM) images. Recent measurements conducted in degassed water showed, however, smooth force versus distance curves, indicating that the hydrophobic force is not an artifact due to nanobubbles.1, 2 Still other investigators3, 4 suggested that the long-range attraction observed between hydrophobic surfaces is due to the correlation between the patches of adsorbed ionic surfactant and the patches of unoccupied surface. For this theory to work, it is necessary that the charged patches be laterally mobile to account for the strong attractive forces observed in experiment. In an effort to test this theory, AFM force measurements were conducted with gold substrates hydrophobized by self-assembly of alkanethiols and xanthates of different chain lengths. The results showed long-range attractions despite the fact that the hydrophobizing agents chemisorb on gold and, hence, the adsorption layer is immobile. When the gold surfaces were hydrophobized in a 1 Ã 10-3 M thiol-in-ethanol solution for an extended period of time, the force curves exhibited steps. These results indicate that the long-range attractions are caused by the coalescence of bubbles, as was also reported by Ederth.5 The steps disappeared, however, when the species adsorbed on top of the chemisorbed monolayer were removed by solvent washing, or when the gold substrates were hydrophobized in a 1 Ã 10-5 M solution for a relatively short period of time. AFM force measurements were also conducted between gold substrates coated with short-chain thiols and xanthates to obtain hydrophobic surfaces with water contact angles (ï ±) of less than 90o. Long-range attractions were still observed despite the fact that cavitation is thermodynamically not possible. Having shown that hydrophobic force is not due to coalescence of pre-existing bubbles, cavitation, or correlation of charged patches, the next set of force measurements was conducted in ethanol-water mixtures. The attractive forces became weaker and shorter-ranged than in pure water and pure ethanol. According to the Derjaguin's approximation6, an attractive force arises from the decrease in the excess free energy (ï §f) of the thin film between two hydrophobic surfaces.7 Thus, the stronger hydrophobic forces observed in pure water and pure ethanol can be attributed to the stronger cohesive energy of the liquid due to stronger H-bonding. Further, the increase in hydrophobic force with decreasing separation between two hydrophobic surfaces indicates that the H-bonded structure becomes stronger in the vicinity of hydrophobic surfaces. The force measurements conducted at different temperatures in the range of 10-40C showed that the hydrophobic attraction between macroscopic surfaces causes a decrease in film entropy (Sf), which confirms that the hydrophobic force is due to the structuring of water in the thin film between two hydrophobic surfaces. The results showed also that the hydrophobic interaction entails a reduction in the excess film enthalpy (Hf), which may be associated with the formation of partial (or full) clathrates formed in the vicinity of hydrophobic surfaces. The presence of the clathrates is supported by the recent finding that the density of water in the vicinity of hydrophobic surfaces is lower than in the bulk.8 / Ph. D.

The UN predicts that by 2050 there will water shortages throughout the globe. Current sources for safe, clean drinking water are being over mined and exhausted. Seawater provides an alternative water source, but a high salt content makes it unsuitable for the majority of applications. However, reverse osmosis lowers the salt content producing water that is safe for human consumption. Reverse osmosis uses a semi-permeable membrane to prevent the transport of salt but allows for the transport of water. Currently these membranes are susceptible to fouling and contamination, which reduces their efficiency. Graphene-oxide membranes offer a new material for reserves osmosis membranes. Sheets of graphene-oxide are stacked in a layered structure. The separation between the sheets can be controlled using physical confinement, resulting in limited ion permeation of abundant cations in seawater, like Na+ and K+. This is believed to be due to the separation of 0.76 nm between the graphene sheets, forcing the ions to lose its surrounding water molecules, making it unfavourable for the ion to travel through the membrane. Molecular dynamics simulations can give an atomic level insight into the molecular processes within GO membranes. Recent simulations have shown that charged species are attracted to graphene surfaces due to polarisation of the pi-electron system. This work has managed to incorporate these ion-pi interactions into molecular dynamics simulations. Including ion-pi interactions caused some ions, like Na+ and K+, to prefer to lose water molecules and reside at a graphene surface. This work observed the same phenomena when ions were confined to graphene channel ranging from 1.3 nm - 0.7 nm. This observation could have a large impact on whether dehydration is limiting the permeation of these two ions, or if there are additional processes that limit their molecular transport.

Understanding the structure and dynamics of molecularly thin films or the state of water confined to nanoscale dimensions is an active field of research and has wide applications in areas ranging from biology to geology. The issues concern fundamental aspects related to the manner in which a substrate influences the organization of water, origin of forces present when water is confined to nanoscale dimensions, and the influence on the structure and dynamics of water adjacent to a surface. The focus of this thesis lies in examining the thermodynamics and transport properties of interfacial and confined water. As a prelude to studying the structure of water confined between two mica surfaces, we first investigated the structuring of water adjacent to a single mica surface using grand canonical Monte Carlo (GCMC) simulations. The adsorption isotherm reveals three distinct stages as the relative vapor pressure in increased. The derived film thickness, isotherm shape, and heats of adsorption are in excellent agreement with recent experimental data. Our study does not support the 2D ice hypothesis and indicates that beyond the first adsorbed layer water is liquid-like. The characteristics of water confined to nanometer dimensions between two hydrophilic surfaces are investigated to assess the influence of chemical functionality of the hydrophilic surface on the structure of confined water. Our study shows that hydration of potassium ions on the mica surface has a strong influence on the water structure and solvation force response of confined water. In contrast to the disrupted hydrogen bond network observed for water confined between mica surfaces, water between silica surfaces is able to retain its hydrogen bond network displaying bulk-like structural features down to surface separations as small as 0.45 nm. An oscillatory solvation force response is observed only for water confined between silica surfaces. We evaluate and contrast the water density, dipole moment distributions, pair correlation functions and the solvation forces as a function of the surface separation. Recent experimental studies have shown that even for subnanometer confinement, the shear viscosity of water between mica surfaces is only three times larger than the free water viscosity. The dynamics of confined water between mica surfaces is evaluated using molecular dynamics simulations. Our analysis shows that the residence time for water in the contact layer is about two orders of magnitude larger than water in the central bulk-like regions between the surfaces. The K+ ions have a strong influence on the dynamics of confined water, leading to a decoupling in the translation and orientational motions. Our analysis also shows the presence of orientational jump dynamics in the contact layer near the mica surface. We also investigate the influence of confinement on the hydration characteristics of NaCl solutions both as a function of the salt concentration and the surface separation, H between graphite surfaces. A hydration limit is defined as the concentration at which a rapid drop in the hydration number is observed with increasing salt concentration. Despite a high degree of confinement, ions are able to form a quasi two-dimensional hydration shell between the two surfaces. The hydration number, reduces to about 4.15 at a pore width of H =8 A, when compared with the bulk hydration number of 6.25. In many practical situations, surfaces that are separated by an intervening fluid can be dissimilar giving rise to the so called Janus interface. In order to probe the fluid structure in such systems, we studied non-polar fluids confined between two asymmetric surfaces. By varying the degree of asymmetry between the two surfaces a wide variety of adsorption situations are examined using GCMC simulations and a mean field lattice model. The degree of asymmetry is found to influence the presence of frozen phases and can also support co-existing liquid and solid phases.