Thesis (Ph. D.)--Ohio state University, 1927. / Autobiography.

Thesis (Ph. D.)--University of Pennsylvania, 1927.

Techn. Universiẗat, Diss., 2003--Dresden.

The green alga Chlamydomonas reinhardtii can be grown phototrophically using light as an energy source or mixotrophically using reduced carbon in the form of acetate in addition to light. Acetate, despite increasing biomass, also inhibits photosynthesis as compared to cells grown phototrophically. A better understanding of acetate assimilation and how it regulates photosynthesis would enable a more efficient conversion of carbon into valuable products such as biofuels. In this thesis constraint-based modelling techniques are used in conjunction with a genome-scale model of the organism and experimental data to understand this phenomenon. Using flux balance analysis we show that the preferred route of acetate assimilation is likely to be via the enzyme acetyl-CoA synthase, and that exogenous acetate feeds into a modified tricarboxylic acid cycle, which bypasses the CO2 evolution steps. This is consistent with experimental data and explains increases in biomass with mixotrophic growth on acetate in comparison to phototrophic metabolism. Using a cycle decomposition algorithm with a mass-consistent adaptation of the model we were able to examine the role of cycles that further theoretically explain the down-regulation of photosynthesis observed when cells are grown in the presence of acetate. These results suggest that acetate modulates changes in the oxidative pentose phosphate pathway and increases mitochondrial respiration activity. Label-free proteomics was used to quantify 2951 polypeptides with various roles including the assimilatory route of acetate, photosynthesis, the Calvin–Benson cycle, central carbon metabolism and oxidative phosphorylation. We show how acetate assimilation induces a shift in central carbon metabolism to activate the oxidative pentose phosphate pathway. This results in the cycling of electrons around Photosystem I, which accounts for the down-regulation of photosynthesis.

The study deals with the formulation development and thermorheological properties of crumb rubber/ethylene vinyl acetate (EVA) modified bitumen with the aim of optimizing the amount of crumb rubber and EVA loadings in bitumen based on thermorheological parameters complex shear modulus, phase angle and rutting parameter. In the modified binders EVA offers plastomer properties whereas the crumb rubber confers elasticity to the bitumen. 13.75% crumb rubber and 2.5% EVA loadings based on aging indices gave the best optimized mixture. The thermorheological behaviour of the best optimized mixture was compared to industrial grade EVA (AP-1) and crumb rubber (AR-1) modified bitumen. Improving aging behaviour of the bitumen was evaluated using four antioxidants: carbon black, hydrated lime, Irganox 1010 and Irgafos 168. The least aging indices at 58˚C and 64˚C were obtained from a 1:1:1 Irganox 1010/hydrated lime/carbon black mixture. SARA (saturates, aromatics, resins and asphaltene) analysis gave the chemical background for application of antioxidants to reduce the propensity of short term aging. To further improve the EVA/crumb rubber optimized mixture for workability FT wax (Sasobit®) was assayed at loadings from 0-2.5%. This was done to match the EVA content and maintain the original maximum loading of 2.5% in the optimized mixture. The phase change abilities of FT wax owing to the high latent heat enabled co-crystallization with the EVA with the elastomeric backbone of crumb rubber acting as support material. The energy-sustainability nexus was found to have worked at less than 1% loading of FT wax in the EVA/crumb rubber modified bitumen. Response surface methodology approach to all the sections of work was used to come up with the optimized mixtures based on rheological parameters complex shear modulus, phase angle and rutting parameter at test temperature 64˚C. The interaction chemistry of bitumen, crumb rubber, EVA and FT wax was found to be first and second order in all cases involving individual contributions and co-interaction amongst the factors. Project costing for each section of work (optimizing section, antioxidant section and FT wax section) was conducted involving the raw materials used, equipment used, labour involved and other costs incurred for all the project work.

Yes / In this work, for the first time, the synthesis of benzyl acetate via the esterification of acetic acid and benzyl alcohol is investigated in the reactive distillation system using a middle vessel (MVD), inverted (IBD), and conventional batch reactive distillation columns. The measurement of the performance of these column schemes is determined in terms of profitability through minimization of the batch time for a defined separation task. The control variables (reboil ratio for MVD, IBD columns) and (reflux ratio in case of CBD column) are considered as piecewise constants over batch time. The optimization results obviously indicate that the CBD system is a more attractive process in terms of batch time reduction, and maximum achievable yearly profit as compared to the MVD, and IBD operations.

No description available.

The oxidation of 4-t-butyltoluene in glacial acetic acid by hydrogen peroxid in a process catalysed by cobalt(II) acetate tetrahydrate and sodium bromide has been studied with the aim of increasing the selectivity towards 4-t-butylbenzaldehyde.

Thesis (Ph. D.)--Virginia Polytechnic Institute, 1956. / Typewritten. Vita. Bibliography: p. 110-114. Also available via the Internet.

No description available.