Sulfonylammonium Ions: Applications In Mechanistic And Synthetic Organosulfur Chemistry

This thesis describes the results obtained from two projects in organosulfur chemistry; both of which involve the use of sulfonylammonium ions. The two projects undertaken involved sulfenes and 3-alkoxysulfonyl trialkylpropanaminium salts ( {lcub}3{rcub}betylates ).;The first project describes efforts undertaken to delineate more precisely the reaction mechanisms of sulfenes, a highly reactive species. The reaction mechanism of sulfene was studied by allowing multiexchange to occur with deuterated traps. Methanol-d was used as the trapping agent in benzene-acetonitrile and deuterium oxide as the trap in a buffered deuterium oxide-dimethoxyethane system. The investigations made use of methanesulfonyl chloride and a series of trialkyl(methylsulfonyl)ammonium fluorosulfate salts as starting materials. The multiexchange results were used to deduce aspects of the mechanism. The results obtained showed that nucleophilic catalysis was not a significant path for formation of sulfene from sulfonyl chlorides when triethylamine was used to promote sulfene formation cut that less hindered amines may react with methane sulfonyl chloride via nucleophilic catalysis to some extent.;The second project involves the synthesis and reactions of {lcub}3{rcub}Betylates(3-(Alkoxysulfonyl)propanaminium salts). {lcub}3{rcub}Betylates are an example of a new type of substrate for aliphatic nucleophilic substitution which enhance the applicability of nucleophilic substitution reactions to problems in organic synthesis by providing a good nucleofuge and phase transfer reagent in one substrate. Unlike their lower homologs, the 2-(alkoxysulfonyl)-ethanimium salts ({lcub}2{rcub}betylates), the {lcub}3{rcub}betylates were found to be quite stable to elimination and thus allow clean nucleophilic substitution with a wider variety of nucleophiles. Although {lcub}3{rcub}betylates are somewhat less reactive than {lcub}2{rcub}betylates they appear to be able to undergo any reaction characteristics of a {lcub}2{rcub}betylates. The {lcub}3{rcub}betylates were synthesized by the reaction of a cyclic sulfonylammonium ion (2,2-dimethylisothiazolidinium 1,1-dioxide fluorosulfate) with alcohols and triethylamine

Experimental testing of four correction algorithms for the forward scattering spectrometer probe

Three number density correction algorithms and one size distribution correction algorithm for the Forward Scattering Spectrometer Probe (FSSP) were compared with data taken by the Phase Doppler Particle Analyzer (PDPA) and an optical number density measuring instrument (NDMI). Of the three number density correction algorithms, the one that compared best to the PDPA and NDMI data was the algorithm developed by Baumgardner, Strapp, and Dye (1985). The algorithm that corrects sizing errors in the FSSP that was developed by Lock and Hovenac (1989) was shown to be within 25 percent of the Phase Doppler measurements at number densities as high as 3000/cc

Variable-camber systems integration and operational performance of the AFTI/F-111 mission adaptive wing

The advanced fighter technology integration, the AFTI/F-111 aircraft, is a preproduction F-111A testbed research airplane that was fitted with a smooth variable-camber mission adaptive wing. The camber was positioned and controlled by flexing the upper skins through rotary actuators and linkages driven by power drive units. The wing camber and control system are described. The measured servoactuator frequency responses are presented along with analytical predictions derived from the integrated characteristics of the control elements. A mission adaptive wing system chronology is used to illustrate and assess the reliability and dependability of the servoactuator system during 1524 hours of ground tests and 145 hours of flight testing

Detection Sensitivity Optimization of Optical Signals Generated by Fiber Optic Bragg Gratings Under Dynamic Excitation

The dynamic response of a fiber optic Bragg grating to mechanical vibrations is examined both theoretically and experimentally. The theoretical expressions describing the consequences of changes in the grating\u27s reflection spectrum are derived for partially coherent beams in an interferometer. The analysis is given in terms of the dominant wavelength, optical bandwidth, and optical path difference of the interfering signals. Changes in the reflection spectrum caused by a periodic stretching and compression of the grating are experimentally measured using an unbalanced Michelson interferometer, a Michelson interferometer with a nonzero optical path difference. The interferometer\u27s sensitivity to changes in the dominant wavelength of the interfering beams is measured as a function of interferometer unbalance and is compared to theoretical predictions. The theoretical analysis enables the user to determine the optimum performance for an unbalanced interferometer. (C) 2003 Society of Photo-Optical Instrumentation Engineers

Investigating local policy drivers for alcohol harm prevention: a comparative case study of two local authorities in England

AbstractBackground The recent transfer of public health teams to local authorities in England offers opportunities for new policy approaches to tackling alcohol harm. The new responsible authority status of directors of public health, for example with regard to licensing applications, raises the prospect of reducing excessive alcohol consumption through local availability measures. Local authorities are also responsible for the commissioning of community-based treatment services. We used a case study approach to identify the major drivers and characteristics of local alcohol policies and services in two contrasting local authorities. Methods The many sources used were semi-structured interviews with key informants, including two in public health, two in licensing and trading standards, one in the police, and one information specialist; documentary analysis, including two alcohol strategies; two statements of licensing policy; and field observation (attending a licensing committee hearing). Focusing on alcohol harm prevention programmes and their underlying objectives, we used storyboards and constant comparative methods to describe and explain differences in the alcohol policy landscape between the two local authorities. Ethics approval was obtained from the University of Sheffield Ethics Committee. Findings Substantial differences in the stated priorities of alcohol harm prevention strategies were shown in the contrasting policy responses of the two local authorities. Concern about how best to reduce high rates of alcohol-related hospital admissions in local authority 1 led to an emphasis on health-service approaches, such as screening and brief intervention, whereas a public disorder focus in local authority 2 resulted in policies aimed at reducing availability through licensing measures. Perceived tensions were apparent for local authority 1 between maintaining a supportive environment for local businesses at a time of economic recession and introducing policy measures with a regulatory focus. Field observations highlighted the underlying importance of well-functioning working relationships between licensees and all responsible authorities, for achieving acceptable implementation plans for novel policies. Resource constraints and a lack of clear policy champions were also barriers to more preventive measures in local authority 1. Interpretation Devolved responsibility for alcohol harm prevention clearly presents the potential for local authorities to tailor policies closely to their identified population needs. The exercising of responsible authority status in reducing availability through licensing approaches is best achieved however when fully integrated into the full spectrum of alcohol harm reduction activities, from prevention through to treatment-based interventions

Ignorance management: an alternative perspective on knowledge management in multinational organisations

This paper identifies an alternative perspective on Knowledge Management (KM) in multinational organisations by definition of the concept of Ignorance Management. Furthermore, this paper discusses the difficulties employees face in understanding and comprehending what they need to know to do their jobs, and what implications this can have within global technology intensive environments. The focus is given in particular on multinational organisations where innovation and new knowledge is essential to both short-term opportunistic value capture and longer term business sustainability. Hence, this paper discusses why managing ignorance is essential for maintaining a strategic knowledge sharing culture within multinational organisations. Furthermore, it develops a novel theory on the nature of knowledge and ignorance while making the distinction between knowns and unknowns as well as between consciousness and ignorance. The theoretical findings have been applied to technology intensive and innovative environments. A case study is explored within the paper, based on findings from one of the largest military contractors in the world, which employs over 100,000 people across the globe. The paper adopts an interpretivist philosophy, using the primary strategy of qualitative research. In addition, due to the complexity of the topic, a mixed methods approach has been used for the data collection process. Moreover, participatory action research is undertaken to study individuals’ actions in a particular context and improve organisational strategies and KM practices. The study shows that managing ignorance and adaptiveness in multinational organisations is becoming increasingly important. Thus, the critical question is not just managing what is known but also trying to find ways to manage the unknown. This viewpoint of acknowledging ignorance, if successfully incorporated within a company’s KM strategy, will not only facilitate and enhance knowledge storage and transmission processes but will also undoubtedly play a vital role when referring to a company’s efficiency, productivity and overall performance

Rayleigh-Brillouin Scattering to Determine One-Dimensional Temperature and Number Density Profiles of a Gas Flow Field

Rayleigh-Brillouin spectra for heated nitrogen gas were measured by imaging the output of a Fabry-Perot interferometer onto a CCD array The spectra were compared with the theoretical 6-moment model of Rayleigh-Brillouin scattering convolved with the Fabry-Perot instrument function. Estimates of the temperature and a dimensionless parameter proportional to the number density of the gas as functions of position in the laser beam were calculated by least-squares deviation fits between theory and experiment