4 resultados para BRANCHED POLYETHYLENES

em Brock University, Canada


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Linear alkylbenzenes, LAB, formed by the Alel3 or HF catalyzed alkylation of benzene are common raw materials for surfactant manufacture. Normally they are sulphonated using S03 or oleum to give the corresponding linear alkylbenzene sulphonates In >95 % yield. As concern has grown about the environmental impact of surfactants,' questions have been raised about the trace levels of unreacted raw materials, linear alkylbenzenes and minor impurities present in them. With the advent of modem analytical instruments and techniques, namely GCIMS, the opportunity has arisen to identify the exact nature of these impurities and to determine the actual levels of them present in the commercial linear ,alkylbenzenes. The object of the proposed study was to separate, identify and quantify major and minor components (1-10%) in commercial linear alkylbenzenes. The focus of this study was on the structure elucidation and determination of impurities and on the qualitative determination of them in all analyzed linear alkylbenzene samples. A gas chromatography/mass spectrometry, (GCIMS) study was performed o~ five samples from the same manufacturer (different production dates) and then it was followed by the analyses of ten commercial linear alkylbenzenes from four different suppliers. All the major components, namely linear alkylbenzene isomers, followed the same elution pattern with the 2-phenyl isomer eluting last. The individual isomers were identified by interpretation of their electron impact and chemical ionization mass spectra. The percent isomer distribution was found to be different from sample to sample. Average molecular weights were calculated using two methods, GC and GCIMS, and compared with the results reported on the Certificate of Analyses (C.O.A.) provided by the manufacturers of commercial linear alkylbenzenes. The GC results in most cases agreed with the reported values, whereas GC/MS results were significantly lower, between 0.41 and 3.29 amu. The minor components, impurities such as branched alkylbenzenes and dialkyltetralins eluted according to their molecular weights. Their fragmentation patterns were studied using electron impact ionization mode and their molecular weight ions confirmed by a 'soft ionization technique', chemical ionization. The level of impurities present i~ the analyzed commercial linear alkylbenzenes was expressed as the percent of the total sample weight, as well as, in mg/g. The percent of impurities was observed to vary between 4.5 % and 16.8 % with the highest being in sample "I". Quantitation (mg/g) of impurities such as branched alkylbenzenes and dialkyltetralins was done using cis/trans-l,4,6,7-tetramethyltetralin as an internal standard. Samples were analyzed using .GC/MS system operating under full scan and single ion monitoring data acquisition modes. The latter data acquisition mode, which offers higher sensitivity, was used to analyze all samples under investigation for presence of linear dialkyltetralins. Dialkyltetralins were reported quantitatively, whereas branched alkylbenzenes were reported semi-qualitatively. The GC/MS method that was developed during the course of this study allowed identification of some other trace impurities present in commercial LABs. Compounds such as non-linear dialkyltetralins, dialkylindanes, diphenylalkanes and alkylnaphthalenes were identified but their detailed structure elucidation and the quantitation was beyond the scope of this study. However, further investigation of these compounds will be the subject of a future study.

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The representation of a perceptual scene by a computer is usually limited to numbers representing dimensions and colours. The theory of affordances attempted to provide a new way of representing an environment, with respect to a particular agent. The view was introduced as part of an entire field of psychology labeled as 'ecological,' which has since branched into computer science through the field of robotics, and formal methods. This thesis will describe the concept of affordances, review several existing formalizations, and take a brief look at applications to robotics. The formalizations put forth in the last 20 years have no agreed upon structure, only that both the agent and the environment must be taken in relation to one another. Situation theory has also been evolving since its inception in 1983 by Barwise & Perry. The theory provided a formal way to represent any arbitrary piece of information in terms of relations. This thesis will take a toy version of situation theory published in CSLI lecture notes no. 22, and add to the given ontologies. This thesis extends the given ontologies to include specialized affordance types, and individual object types. This allows for the definition of semantic objects called environments, which support a situation and a set of affordances, and niches which refer to a set of actions for an individual. Finally, a possible way for an environment to change into a new environment is suggested via the activation of an affordance.

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Inniskillin Wines was founded by Karl Kaiser and Donald Ziraldo in 1975 in Niagara-on-the-Lake, Ontario. They had met the previous year, when Karl Kaiser, a winemaker and chemist, purchased some grapes from Donald Ziraldo, who owned and operated Ziraldo Nurseries. The two shared a vision of producing better quality Canadian wines and formed a partnership, with Kaiser making the wine and Ziraldo serving as company President. In 1975, they were granted a winery license by the LCBO, the first one granted since 1929. The company name Inniskillin was derived from the Inniskilling Fusilliers, an Irish regiment whose Colonel once owned the land that Ziraldo Nurseries occupied. This was the original site of the winery, although in 1978 the winery moved to the Brae Burn Estate, their current location. In 1982 the winery expanded by 50 acres with the addition of the Montague Vineyard, and another 50 acres was acquired in 1991. The Niagara-on-the-Lake vineyard produces single vineyards bottlings of Chardonnay, Pinot Noir, Merlot and Pinot Grigio/Pinot Gris. In 1984, Karl Kaiser began producing icewine from Vidal grapes frozen naturally on the vine. Inniskillin garnered international acclaim for the quality of their icewines, receiving the prestigious Grand Prix d’Honneur at VinExpo in 1991, for their 1989 Vidal icewine. This established Inniskillin as a producer of world class wines, while also raising the profile of Canadian wines in general. The company branched out their operations, first acquiring vineyards in the Napa Valley in 1989 to form Inniskillin Napa (producing wines under the Terra label), and in 1994 establishing Inniskillin Okanagan in the Okanagan Valley in British Columbia. The Napa valley venture ceased in the mid 90’s, while Inniskillin Okanagan continues to operate. In 2006, Karl Kaiser and Donald Ziraldo left Inniskillin. Kaiser retired, while Ziraldo became chair of the Vineland Research and Innovation Center (2006-2011), and remains involved in the wine industry. In 2007, Bruce Nicholson joined Inniskillin as winemaker. Nicholson continues to produce award-winning wines under the Inniskillin label, receiving the top award, the Premio Speciale Gran Award, at Vinitaly 2009 for his 2006 Gold Vidal and his 2006 Sparkling Vidal Icewine. In 2012, he received several awards for the 2008 Riesling Icewine, including gold at the International Wine and Spirits Competition in London, UK, the San Francisco International Wine Championships, and Selections Mondials des Vins Canada.

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Immobilized lipase B from Candida antarctica (Novozym® 435, N435) was utilized as part of a chemoenzymatic strategy for the synthesis of branched polyesters based on a cyclotetrasiloxane core in the absence of solvent. Nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were utilized to monitor the reactions between tetraester cyclotetrasiloxanes and aliphatic diols. The enzyme-mediated esterification reactions can achieve 65– 80% consumption of starting materials in 24–48 h. Longer reaction times, 72–96 h, resulted in the formation of cross-linked gel-like networks. Gel permeation chromatography of the polymers indicated that the masses were Mw ¼ 11 400, 13 100, and 19 400 g mol 1 for the substrate pairs of C7D4 ester/ octane-1,8-diol, C10D4 ester/pentane-1,5-diol and C10D4 ester/octane-1,8-diol respectively, after 48 h. Extending the polymerization for an additional 24 h with the C10D4 ester/octane-1,8-diol pair gave Mw ¼ 86 800 g mol 1. To the best of our knowledge this represents the first report using lipase catalysis to produce branched polymers that are built from a cyclotetrasiloxane core.