5 resultados para POLY(P-PHENYLENEVINYLENE)-RELATED COPOLYMERS

em Brock University, Canada


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The work described in this thesis has been divided into seven sections. The first section involves the preparation of N'-acyl-N'-arylN- benzothiohydrazides by the acylation of N'-aryl-N-benzothiohydrazides and is followed by a brief discussion of their possible conformation in solution. The second section deals with the preparation of 1,3,4-thiadiazolium salts by the action of perchloric acid/acetic anhydride on N'-acylN'- aryl-N-benzothiohydrazides and also by the reaction of N'-arylN- benzothiohydrazides with nitriles in an acidic medium. The preparation of 2-methylthio-I,3,4-thiadiazolium methosulfate by methylating the corresponding thione is also described. The third section deals with the reaction of 2-phenyl- and 2-methyl-I,3,4-thiadiazolium salts with alcohols in the presence of base. The stability and spectra of these compounds are discussed. Treatment of the 2-methyl-I,3,4-thiadiazolium salt with base was found to give rise to a dimeric anhydrobase and evidence supporting its structure is given. The anhydrobase could be trapped by a variety of acylating and thioacylating agents before dimerization occurred. In the fourth section, the reaction of N'-acyl-N'-aryl-N-benzothiohydrazides with a variety of acid anhydrides is described. These compounds were found to be identical with those obtained by acylating the anhydrobase. The mass spectral fragmentation of these compounds is described and the anomolous product obtained upon thiobenzoylation of 3-methyl-l-phenyl-pyrazal-5-one is also discussed. The fifth section deals with thioacyl derivatives of the anhydrobase which were prepared by the action of phosphorus pentasulfide upon the oxygen analogues and also obtained as the major product of the reaction of thioacetic acid with compounds related to N'-aryl-N-benzothiohydrazides. The mass spectra and p.m.r. spectra of these compounds are discussed. In the sixth section, the reaction of the 2-methylthio-l,3,4- thiadiazolium salt with active methylene compounds to give acyl and diacyl derivatives of the anhydrobase is described. Some aspects of these compounds are discussed. The seventh section describes the synthesis of ncyanine~' type dyes incorporating the l,3,4-thiadiazole ring and their spectra are briefly discussed.

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The purpose of this study was to examine the associations between bone speed of sound (SOS) and body composition, osteoporosis-related health behaviours, and socioeconomic status (SES) in adolescent females. A total of 442 adolescent females in grades 9-11 participated. Anthropometric measures of height, body mass, and percent body fat were taken, and osteo-protective behaviours such as oral contraceptive use (OC), physical activity and daily calcium intake were evaluated using self-report questionnaires. Bone SOS was measured by transaxial quantitative ultrasound (QUS) at the distal radius and mid-tibia. The results suggest that fat mass is a significant negative predictor of tibial SOS, while lean mass is positively associated with radial SOS scores and calcium intake was positively associated with tibial SOS scores (p

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This qualitative exploratory research investigates how Canadian Jewish girls understand the discursive stereotype of the Jewish American Princess (JAP), and how they take up these understandings of the J AP in relation to their identities. Three focus groups and six interviews were conducted with girls attending Jewish high schools in Toronto, Canada to explore these questions. From a third wave Jewish feminist perspective, and taking a mediated action approach to identity, two analyses were conducted. A thematic analysis of peer relations, gender, community, and religious understandings demonstrates how aspects of individual identities mediate interpretations of the JAP. A series ofpor t rai t s of JAP-related identity were constructed to analyze how the JAP discursive stereotype also functions as a cultural tool that is taken up by the participants to mediate expressions of their identities. These findings establish the contradictory ways these Jewish girls describe, interpret, and utilize the JAP discursive stereotype, and the complex roles it plays in their social worlds.

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The primary objective of this non-experimental study was to examine the differences based on obesity-related health risk in terms of physical activity, sedentary behaviour and well-being in adults. Participants (N = 50; Mage = 38.50, SDage = 14.21) were asked to wear a SenseWear Armband (SWA) across a seven day monitoring period followed by a questionnaire package. Using the National Institute of Health’s (1998) criteria, participants were classified as either least, increased, or high risk based on waist circumference and Body Mass Index scores. Differences between these classifications were found in the amount of time spent in active energy expenditure for bouts of ten minutes or more (p = .002); specifically between least and high risk (p < .05). No other differences (p > .05) emerged. Participants’ also perceived the SWA as a practical and worthwhile device. Overall, these findings provide practical applications and future directions for health promotional research.

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This article is from the International Journal for the Study of Animal Problems, Vol. 1, No. 1, 1980. The article focuses on the "behavior of different species of livestock as well as different breeds" to aid with the design of handling facilities.