In many countries the current plan for the management of intermediate and high level radioactive wastes is to dispose of the radioactive materials underground in a Geological Disposal Facility (GDF) to prevent release of radioactivity to the environment. In the UK, the repository for intermediate level waste may be backfilled with cementitious material and it is clear that grout and cement will be used during many disposal concepts. Upon saturation, the cement will react creating a region of hyperalkaline geochemical conditions extending away from the GDF, within which, significant changes in radionuclide behaviour are expected. Therefore, this thesis utilises a range of experimental and analytical techniques to try to gain a mechanistic understanding of the behaviour of some key radionuclides (U(VI), Np(V) and Eu(III) as an analogue for Cm(III)/Am(III)) in a range of high pH systems of direct relevance to any cementitious GDF. U(VI) interaction with calcite (calcium carbonate, a common component in high pH cements and the natural environment) surfaces was studied in the 'old' (Ca(OH)2 solution; pH 10.5) and 'young' (Na+, K+, Ca2+; pH 13.3) leachates. In the 'old' leachate, luminescence spectroscopy, batch experiments and kinetic modelling suggested that at low concentrations (smaller or equal to 0.42 µM) a Ca2UO2(CO3)3-like surface complex formed. At higher concentrations, batch experiments, extended X-ray absorption fine structure spectroscopy and luminescence suggested that a surface mediated precipitation mechanism was controlling U(VI) concentrations. Further TEM analysis confirmed that a calcium uranate (CaUO4) solid phase was forming on the calcite surfaces. In the 'young' leachate, batch experiments showed that U(VI) had little affinity for the calcite surface, with no statistically relevant removal from solution observed over a 18 month period. Small angle X-ray diffraction data demonstrated that the U(VI) was probably present in the form of U(VI) intrinsic colloids. Np(V) solubility and sorption to calcite under hyperalkaline conditions were studied using batch, X-ray absorption spectroscopy, and geochemical modelling techniques. It was determined that Np(V) solubility in 'old' cement leachates was consistent with the literature. However, in 'young' cement leachates, an unidentified calcium containing phase was controlling solubility. It was demonstrated that sorption to calcite in 'old' leachates was controlled by the formation of a >CO3NpO2 surface complex, whereas, in the 'young' leachates interaction with the calcite surface was controlled by a precipitation mechanism. Eu(III) sorption to a potential GDF backfill material, Nirex Reference Vault Backfill (NRVB) cement, was studied. The kinetics of removal were rapid with 98.5% Eu(III) removal within 24 hours. Ultrafiltration experiments indicated that all Eu(III) remaining in solution was associated with NRVB derived colloids. Additional experiments using ethylenediaminetetraacetic acid (EDTA) as a competing ligand show that removal from solution was significantly reduced at high concentrations (>0.01 M). These EDTA experiments also indicated some irreversibility in the systems, possibly caused by incorporation into the C-S-H or calcite structures.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mathematics, 1964 / Vita. / Includes bibliographical references (leaves 195-200). / by Henry H. Crapo. / Ph. D. / Ph. D. Massachusetts Institute of Technology, Department of Mathematics

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Calcium aluminate phases are important parts of Ordinary Portland cement and Alumina cement. Various calcium aluminate hydrates originate during the hydration of calcium alumina phases. Their origin depends on the conditions of hydration. In the diploma thesis was investigated hydration of four calcium aluminate phases – CA, CA2, C12A7, C3A under the conditions of four pH – 6, 9, 11, 12,65. Calcium aluminate phases were prepared from CaCO3 and Al2O3 by clinkering in solid phase in laboratory oven. The phases were hydrated for 48 hours. Kinetics of the hydration was investigated by calorimetry. Calcium aluminate hydrates were identified by XRD and DTA.

Non-invasive measurement of pH provides multiple potential benefits in oncology such as better identifying the type of drug that can be more effective in chemotherapy, potentially identifying tumors that are more likely to metastasize and also better assessing the treatment effects. Chemical Exchange Saturation Transfer (CEST) Magnetic Resonance Imaging (MRI) is a versatile non-invasive technique for molecular imaging. AcidoCEST MRI techniques have been developed over the recent years to perform tumor pH measurements by utilizing a contrast agent for which chemical exchange saturation transfer effects depend on the pH of the microenvironment. Quantitative description of CEST MRI signals are generally done via modeling Bloch-McConnell equations by incorporating pH as a parameter or by fitting Lorentzian line shapes to observed z-spectra and then computing a log ratio of the CEST effects from multiple labile protons of the same molecule (ratiometric method). Modeling using Bloch-McConnell equations is complicated and requires careful inclusion of many scan parameters to infer pH. The ratiometric method requires contrast agents that have multiple labile protons, thus making it unsuitable to use for molecules with a single labile proton. Furthermore, depending on the pH, sometimes it might not be possible to numerically compute the ratio due to the inability of detecting signal peaks for certain labile protons. Our aim here is to develop a machine learning based method that learns the CEST signal patterns from observed z-spectra on temperature and concentration-controlled contrast agent phantoms independent of the type of the contrast agent. Our results indicate that the machine learning method provides more general and accurate prediction of pH in comparison to the ratiometric method based on the phantom CEST dataset. Our method is more general in the sense that it does not require explicit modeling of signal peaks that are dependent on the type of contrast agent. We also describe a state of the art variational autoencoder based algorithm extending our machine learning method to measure tumor pH in vivo using AcidoCEST MRI on mouse tumor models.

The diploma thesis deals with sensory assessment, measurement of color and pH of six batches of hop shoots, which differ harvest days and pasteurization, dipping in water overnight and repeated pasteurization. Young shoots of hops were harvested during April. It is a pasteurized product from sweet-sour pickled hop shoots. Results of sensory assessment of hop shoots showed between batches a statistically significant difference (P <0,05) in a number of descriptors. Results of sweet-sour pickle did not showed differences between batches. The difference between batches was only for the purity descriptor. The term of harvest shoots may affect the sensory quality of hop shoots. Dipping of shoots overnight in water and the long-term effect of the pasteurisation temperature worsened the texture and color of the shoots.

Master thesis on topic Influence of liming on yield and quality of corn grain was evaluating yield-making and qualitative parameters of grain maize KWS 9361 in two different variants of fertilizing depending on soil pH treatment with dolomitic limestone in comparison with control variants (without dolomitic limestone). One of these variants was fertilizing with only N rates 110kg N/ha and second of them was fertilizing with NPK fertilizer rates 110 kg N/ha, 50kg P/ha in P2O5 form and 125 kg K/ha in K2O form. No-liming variant fertilized with NPK did significantly have highest yield in all three years (in average 12,07 t/ha). As well the weight of thousand kernel was highest in no-liming variant with NPK fertilizer (average 299 g). Starch content has not been influenced by variants of fertilizing or liming, it has been influenced only by year. Content of crude proteins in grain has been highest in no-liming variant fertilized only with nitrogen (average 7,3 %).

The aim of the diploma thesis was to test the effect of the soil application of carbonation mud on the change of cadmium (Cd) content in soil and plants in the early stages of development. The experiment was based on a precise phytotron pot trial with a defined light, temperature and humidity regime. As the experimental plant, poppy (Papaver somniferum L., variety Major), was used. Silt brown soil was used for experimental vessels. The effect of carbonation mud was evaluated at the level of three variants of applied doses corresponding to 0, 5 and 10 t.ha-1. Cadmium [Cd (NO3)2] was applied in three variants: 1, 5 and 10 mg.kg-1 of soil. The parameters (soil pH, Cd content in the soil, plant weight, Cd content in the plant, Cd plant uptake) were analyzed in three terms during the experiment. From the results of the analyzes it was found that the control soil variant (6.78) and the cadmium variant without carbonation mud (6.87 - 6.88) showed the lowest soil pH. The highest soil pH was observed in variants with the highest doses of applied carbonation mud (7.64 - 7.66). With increasing doses of applied carbonation mud, the available cadmium content in the soil decreased significantly. A positive relationship of higher doses of carbonation mud and dry weight of plants was demonstrated. Plants with the highest dose of carbonation mud achieved the highest average weight. However, this effect was not proven statistically until the last sampling. Also, the content of cadmium in plants, as well as the plants cadmium uptake, was dependent on the doses of carbonation mud. The highest effect on the elimination of cadmium uptake by the plant was found in variants with the highest doses of carbonation mud.

An ion-specific electrode measured cupric ion activity modulated by fulvic acid (FA) and pH in a series of modified Frog Embryo Teratogenesis Assay- Xenopus (FETAX) toxicity assays. Hydrogen ion concentration was the primary determinant of cupric ion activity, while FA played a smaller but significant role. Fulvic acid was a weak copper complexing agent at pH 5.50. At pH 5.50 there was slight reduction of ionic activity and a subsequent attenuation of copper toxicity with 5.0 mg/L FA. At pH 7.50, FA also had a mild attenuating effect on copper toxicity. At pH 6.50, copper was strongly complexed by FA at total copper (TCu) concentrations below its pH-dependent solubility limit. At TCu concentrations above the solubility limit FA enhanced toxicity. There was more cupric ion activity measured in the presence of 0.5 and 5.0 mg/L FA than without it at TCu concentrations above the solubility limit. The proposed mechanism for this behavior was FA action as a nucleation inhibitor. Under the chemical conditions of the pH 6.50 experiments, a stable supersaturation of copper was formed, resulting in a more toxic aqueous matrix.

Liposomal doxorubicin is a clinically important drug formulation indicated for the treatment of several different forms of cancer. For doxorubicin to exert a therapeutic effect, it must gain access to the nucleus. However, a large proportion of the liposomal doxorubicin dose fails to work because it is sequestered within endolysosomal organelles following endocytosis of the liposomes due to the phenomenon of ion trapping. Listeriolysin O (LLO) is a pore-forming protein that can provide a mechanism for endosomal escape. The present study demonstrates that liposomal coencapsulation of doxorubicin with LLO enables a significantly larger percentage of the dose to colocalize with the nucleus compared to liposomes containing doxorubicin alone. The change in intracellular distribution resulted in a significantly more potent formulation of liposomal doxorubicin as demonstrated in both the ovarian carcinoma cell line A2780 and its doxorubicin-resistant derivative A2780ADR.