Investigation and control of alkylsilane stationary phase structure in reversed phase liquid chromatography is presented. Raman spectroscopy is used to probe the alkyl chain conformational order and interchain coupling as a function of various chromatographic conditions. A new method is further developed to fabricate alkylsilane stationary phases with controlled surface coverage. The alkyl chain conformational order and interchain coupling of a series of high-density docosylsilane (C22) bonded stationary phases is shown as a function of temperature, surface coverage, polymerization method, common solvents and solutes. The conformational order of C22 stationary phases is compared to that of octadecylsilane (C18) stationary phases to understand the chain length effect on stationary phase structure. The conformational order information as indicated by Raman spectral order indicators for a C22 phase are correlated with the capacity factor and separation efficiency for each solute studied to gain insight into the retention mechanism. These studies help to understand the origin of stationary phase shape selectivity and the separation process in general. Based on these results, the molecular pictures at the stationary phase/solvent interface are proposed. The effect of pressurized solvent environments on two C18 phases is studied to obtain direct evidence for changes in stationary phase structure due to pressure. These changes are compared to effects of solvation relative to air in the same solvents. In addition, Raman spectral order indicators are identified for perdeuterated alkyl-containing system. This study provides a foundation for studying stationary phase structure in complex systems comprised of long alkyl-containing solutes.A further development of a new method is presented as well for synthesizing alkylsilane stationary phases with precisely controlled surface coverage by using a displaceable surface template monolayer of n-alcohol. A mechanism for this process is proposed based on the studies of n-alcohol concentration and chain length effect on the stationary phase surface coverage. The utility of these new stationary phases as chromatographic support is demonstrated. The shape selectivity for these new phases is comparable to or better than similar phases prepared by conventional methods.

No description available.

Purpose: The purpose of this paper is to examine how age and job identification affect entrepreneurial intention. Design/methodology/approach: The researchers draw on a representative sample of the Austrian adult workforce and apply binary logistic regression on entrepreneurial intention. Findings: The findings reveal that as employees age they are less inclined to act entrepreneurially, and that their entrepreneurial intention is lower the more they identify with their job. Whereas gender, education, and previous entrepreneurial experience matter, leadership and having entrepreneurial parents seem to have no impact on the entrepreneurial intention of employees. Research implications: Implications relate to a contingency perspective on entrepreneurial intention where the impact of age is exacerbated by stronger identification with the job. Practical implications: Practical implications include the need to account for different motivational backgrounds when addressing entrepreneurial employees of different ages. Societal implications include the need to adopt an age perspective to foster entrepreneurial intentions within established organizations. Originality/value: While the study corroborates and extends findings from entrepreneurial intention research, it contributes new empirical insights to the age and job - dependent contingency perspective on entrepreneurial intention. (authors' abstract)

This study deals with a very common problem encountered in many automotive industries. Automotive companies try to level the production of different models over time based on the demands for these models in the market. In order to achieve this, they introduce a leveled stream of cars in the beginning of the production line. But because of many reasons this leveled stream gets disturbed in its course. In order to re-level the stream, buffers are used between the shops. One such buffer is called as selectivity bank and it sits between paint shop and assembly shop. This buffer receives a disturbed sequence from the paint shop. The thesis tries to develop different algorithms that can be used to discharge cars from this buffer in order to achieve better leveling in the presence of rework and assembly constraints. These algorithms continuously try to steer the system from an undesirable state to a more desirable state by keeping track of current conditions in the plant. A simulation model is developed, which gives a platform for comparing relative performance of these logics under different conditions. The simulation tool is also helpful in designing optimum size of this buffer that will result in desired leveling performance.

The conversion of switchgrass lignin, a renewable source for chemicals and fuels, is investigated using reactions such as depolymerization, hydrodeoxygenation and alkylation. First, the lignin is converted into oils containing phenol, substituted guaiacols and other smaller lignin fragments using formic acid and Pt/C through a batch process. A long reaction time was observed to crucial to yield oils with the highest fraction of lower molecular weight compounds with the lowest O/C and highest H/C molar ratio. Second, the zeolite catalyzed gas phase alkylation of phenol, a model compound for the lignin oil, with propylene was investigated. Zeolite pore topology and acid strength were shown to influence the selectivity for the target product, 2-isopropylphenol. This work shows that the conversion of lignin to useful products is possible and suggests some future work to consider before it can be implemented practically.

Thesis (Ph. D.)--University of Notre Dame, 2007. / Thesis directed by Brad S. Gibson for the Department of Psychology. "April 2007." Includes bibliographical references (leaves 119-134).

Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 1999. / Vita. Includes bibliographical references (leaves 192-203).

Dissertation (Ph.D.)--The University of North Carolina at Greensboro, 2009. / Title from PDF t.p. (viewed May 17, 2010). Directed by David Teachout; submitted to the School of Music. Includes bibliographical references (p. 191-206).

Thesis (Ph.D.)--University of Delaware, 2005. / Principal faculty advisor: Hoffman, James E., Dept .of Psychology. Includes bibliographical references.

Local descriptors are increasingly used for the task of object recognition because of their perceived robustness with respect to occlusions and to global geometrical deformations. We propose a performance criterion for a local descriptor based on the tradeoff between selectivity and invariance. In this paper, we evaluate several local descriptors with respect to selectivity and invariance. The descriptors that we evaluated are Gaussian derivatives up to the third order, gray image patches, and Laplacian-based descriptors with either three scales or one scale filters. We compare selectivity and invariance to several affine changes such as rotation, scale, brightness, and viewpoint. Comparisons have been made keeping the dimensionality of the descriptors roughly constant. The overall results indicate a good performance by the descriptor based on a set of oriented Gaussian filters. It is interesting that oriented receptive fields similar to the Gaussian derivatives as well as receptive fields similar to the Laplacian are found in primate visual cortex.