519 research outputs found
Crystal and molecular structures of [Ru3(m-H)(m3-h1:h1:h3-C12H17)(CO)9]: revision of a previous determination
No full textMichael I. Bruce , Hoong-Kun Fun , Brian K. Nicholson , Omar bin Shawkataly and Ralph A. Thomso
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The reactions of electron-rich monomers with electrophilic compounds: Methyl tricyanoethylenecarboxylate and trimethylsilyl esters.
No full textThe experimental results of the current work has three parts. First, the cycloaddition and copolymerization of methyl tricyanoethylenecarboxylate 2 with electron-rich olefins, such as p-methoxystyene, trans-anethole, isobutyl vinyl ether and ethyl cis-propenyl ether are discussed. The nature of the cycloadduct is determined by the orientation of the electrophilic olefins. Copolymerization of 2 with p-methoxystyrene under free-radical initiation gave an alternating copolymer. Second, trimethylsilyl methanesulfonate and trimethylsilyl diphenylphosphate were used as initiators for cationic polymerization. In the presence or absence of hindered pyridine, trimethylsilyl diphenylphosphate and trimethylsilyl methanesulfonate did not initiate the polymerization of p-methoxystyrene, anethole, 4-isopropenylanisole, 1,3-dioxolane or trioxane. Only trimethylsilyl methanesulfonate was able to initiate the cationic polymerization of 1,3-dioxepane in the presence of a hindered base. A model study demonstrates fast desilylation of a carbocation β to a silicon by an oxygen-containing counterion. Finally, block copolydioxepane-polydimethylsiloxane has been synthesized by the "silyl sulfonate approach." In this approach, the nucleophilic macromer, lithium polydimethylsiloxanate, was reacted with chlorodimethylsilane or allylchlorodimethylsilane to produce the corresponding macromers with silylated end groups. They contained a labile substituent, an allyl or a proton, on silicon. These macromers were then converted to electrophilic macropolydimethylsiloxane arylsulfonate by reaction with an aryl or alkyl sulfonic acid. The sulfonate polydisiloxanes can initiate the cationic polymerization of 1,3-dioxepane to yield block polydimethylsiloxane-polydioxepane. This cationic polymerization did proceed in the presence of 2,6-di-t-butylpyridine, which would trap any acid impurities.The experimental results of the current work has three parts. First, the cycloaddition and copolymerization of methyl tricyanoethylenecarboxylate 2 with electron-rich olefins, such as p-methoxystyene, trans-anethole, isobutyl vinyl ether and ethyl cis-propenyl ether are discussed. The nature of the cycloadduct is determined by the orientation of the electrophilic olefins. Copolymerization of 2 with p-methoxystyrene under free-radical initiation gave an alternating copolymer. Second, trimethylsilyl methanesulfonate and trimethylsilyl diphenylphosphate were used as initiators for cationic polymerization. In the presence or absence of hindered pyridine, trimethylsilyl diphenylphosphate and trimethylsilyl methanesulfonate did not initiate the polymerization of p-methoxystyrene, anethole, 4-isopropenylanisole, 1,3-dioxolane or trioxane. Only trimethylsilyl methanesulfonate was able to initiate the cationic polymerization of 1,3-dioxepane in the presence of a hindered base. A model study demonstrates fast desilylation of a carbocation β to a silicon by an oxygen-containing counterion. Finally, block copolydioxepane-polydimethylsiloxane has been synthesized by the "silyl sulfonate approach." In this approach, the nucleophilic macromer, lithium polydimethylsiloxanate, was reacted with chlorodimethylsilane or allylchlorodimethylsilane to produce the corresponding macromers with silylated end groups. They contained a labile substituent, an allyl or a proton, on silicon. These macromers were then converted to electrophilic macropolydimethylsiloxane arylsulfonate by reaction with an aryl or alkyl sulfonic acid. The sulfonate polydisiloxanes can initiate the cationic polymerization of 1,3-dioxepane to yield block polydimethylsiloxane-polydioxepane. This cationic polymerization did proceed in the presence of 2,6-di-t-butylpyridine, which would trap any acid impurities.The experimental results of the current work has three parts. First, the cycloaddition and copolymerization of methyl tricyanoethylenecarboxylate 2 with electron-rich olefins, such as p-methoxystyene, trans-anethole, isobutyl vinyl ether and ethyl cis-propenyl ether are discussed. The nature of the cycloadduct is determined by the orientation of the electrophilic olefins. Copolymerization of 2 with p-methoxystyrene under free-radical initiation gave an alternating copolymer. Second, trimethylsilyl methanesulfonate and trimethylsilyl diphenylphosphate were used as initiators for cationic polymerization. In the presence or absence of hindered pyridine, trimethylsilyl diphenylphosphate and trimethylsilyl methanesulfonate did not initiate the polymerization of p-methoxystyrene, anethole, 4-isopropenylanisole, 1,3-dioxolane or trioxane. Only trimethylsilyl methanesulfonate was able to initiate the cationic polymerization of 1,3-dioxepane in the presence of a hindered base. A model study demonstrates fast desilylation of a carbocation β to a silicon by an oxygen-containing counterion. Finally, block copolydioxepane-polydimethylsiloxane has been synthesized by the "silyl sulfonate approach." In this approach, the nucleophilic macromer, lithium polydimethylsiloxanate, was reacted with chlorodimethylsilane or allylchlorodimethylsilane to produce the corresponding macromers with silylated end groups. They contained a labile substituent, an allyl or a proton, on silicon. These macromers were then converted to electrophilic macropolydimethylsiloxane arylsulfonate by reaction with an aryl or alkyl sulfonic acid. The sulfonate polydisiloxanes can initiate the cationic polymerization of 1,3-dioxepane to yield block polydimethylsiloxane-polydioxepane. This cationic polymerization did proceed in the presence of 2,6-di-t-butylpyridine, which would trap any acid impurities.This item was digitized from a paper original and/or a microfilm copy. If you need
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Ferroelastic Phase Transition In Some Phenols-Amines Adducts – Experimental And Theoretical Findings.
No full textA new type of structural phase transition has been discovered recently in a class of hydrogen-bonded organic crystals
Letter from H.K Lewis & Co. LTD to Dr. Alfred E. Cohn
No full textLetter from H.K Lewis & Co. LTD to Dr. Alfred E. Cohn, 1934
Alfred E. Cohn (1879-1957), physician, humanist, author, and bibliophile, was one of the first cardiologists in the United States. He was born in New York City and received an MD from the College of Physicians and Surgeons at Columbia University in 1904. Between 1907 and 1909 he studied in Freiburg, Vienna, and London. When he returned to the United States, Dr. Cohn joined the staff of Mount Sinai Hospital in New York. In 1911, he moved to the Rockefeller Hospital, bringing his electrocardiograph with him. He remained at Rockefeller for the rest of his career, retiring in 1944. Dr. Cohn took a leading role in organizations such as the New York Heart Association, New York Academy of Medicine, Veterans Administration, China Medical Board, Asia Institute, Sydenham Hospital, and the Committee for Displaced Foreign Scholars and Displaced Foreign Physicians.https://digitalcommons.rockefeller.edu/objects-tell-stories/1010/thumbnail.jp
Quantitative analysis of the effects of audio biofeedback on weight-bearing characteristics of persons with transtibial amputation during early prosthetic ambulation
No full textAuthor name used in this publication: Daniel H.K. ChowVersion of RecordPublishedVoR allowe
Multimodal recognition of emotions
No full textThis thesis proposes algorithms and techniques to be used for automatic recognition of six prototypic emotion categories by computer programs, based on the recognition of facial expressions and emotion patterns in voice. Considering the applicability in real-life conditions, the research is carried in the context of devising person independent methods that should be robust to various factors given the specificity of the considered modalities. An immediate focus represents the development of audio-visual algorithms and their implementation in form of software applications for automatic recognition of emotions.MediamaticaElectrical Engineering, Mathematics and Computer Scienc
Mahatma Gandhi and the depressed classes
No full textBiennial Professor H.K. Barpujari endowment lectures(2005-06) delivered by the author at Kolkata during 21-22 February 2006
Enformasyon Bilimlerine Fütüristik Bir Yaklaşım
No full textIn the Information Age, the amount of unique information created every year reaches a level high enough to fill the American Library of Congress 37,000 times and 92% of this bulk is recorded on magnetic media. For the upcoming younger generation, information recorded on paper is “out of coverage area.” They tend to reach information on the spot, via some intelligent informational agents. Thus, they think information that cannot be accessed in increasingly shorter periods of time is not worth accessing. Traditional functions, like presentation of information, trusted information storage, maintaining authenticity and conservation, expected to be fulfilled by information professionals, are becoming increasingly electronic focused, in parallel to the changing world. The level of technical information infrastructure required to fulfill these functions in an electronic environment, on the other hand, has reached a level that requires information sciences to turn into an “information engineering.” Setting out from these changes, this paper questions the ratio of technological aspects to be taught during the education of information professionals and concludes that the place that this education should take place should be reconsidered
Modelling Pile Installation Effects: A Numerical Approach
No full textOne of the most traditional methods for supporting structures resting on soft soils is the use of piles. They generally work by transferring the loads to deeper soil layers, which can provide sufficient bearing capacity when mobilised. This type of foundations has been commonly used throughout the world and also in the western part of the Netherlands due to the typical soil profile which consists of a thick (10-20 m) soft soil layer underlain with a stiff bearing stratum composed mostly of quartz sand. In this perspective, this study sheds a light on the behaviour of piles installed in silica sand. The bearing capacity of a pile depends on the soil properties and the stress state it is surrounded with. This is because the behaviour of granular material is governed by the packing of the grains and the contact stresses in between. The mean stress and the density can be described as the soil state, and the soil behaviour is determined on the basis of this state and the loading conditions. In the case of a displacement pile, the installation process causes a considerable amount of soil displacement and high levels of (reaction) stresses. These effects of pile installation are transmitted to soil through the interaction between sand grains and the pile, resulting in an altered soil state and properties. A more realistic behaviour and therefore an improved design would be achieved by considering the installation effects in the analyses than performing the analysis considering a geostatic stress state around the pile(s) modelled. In current practice, the installation effects are taken into account by some empirical design methods in order to estimate the bearing capacity of foundation piles. Several field and model tests performed to investigate the influence of pile installation on the bearing capacity, have led to an evolution of the empirical models to estimate the bearing capacity of displacement piles. Recent attempts to investigate the change in the soil state were also limited either to the measurement domain (generally close to the pile) or resolution as well as the variables (e.g. displacement, strain, stress, density) that can be quantified. However, the behaviour of piles during installation, the interaction with the surrounding soil and the resulting alteration of soil properties during installation are still not well known. This information is essential, not only to make better predictions of the pile bearing capacity and its behaviour in the soil under different loading conditions, but also to be able to predict the (side) effects of pile installation on the neighbourhood. This study is the numerical part of a larger project in which the installation effects of displacement piles are investigated both experimentally and numerically. The objective of this numerical study is to investigate the installation effects of pile jacking in sand in a numerical framework. Since the jacking operation can be considered as quasi-static loading, the dynamic effects are not considered in the analyses. For the same reason, drained conditions are assumed such that the pore pressures are only taken into account as a reduction of total stress (giving the effective stresses). As a common tool used in engineering practice, FE modelling is selected as the numerical method. In order to model pile jacking using the FEM in a standard FE code, some additional aspects have to be considered to account for the large deformation effects. In this perspective possibilities to simulate installation effects as well as the installation process were investigated and a simplified technique (the Press-Replace technique) is proposed. After a sensitivity study, the method is employed to investigate the installation effects around a jacked pile for different sand densities. In the view of the results obtained from FE simulations, the possibilities of incorporating the installation fields were investigated. Furthermore, describing the installation effects in a functional form, which allows flexibility for imposing the installation field around a so-called wished-in-place pile to model it as a jacked pile, was studied. A novel technique is introduced to describe the installation effects of a jacked pile without simulating the penetration process. This way a jacked pile can be modelled wished-in-place and corresponding installation effects (i.e. stress, density and stiffness change) can be imposed. By the proposed method, there will be an enormous gain in term of computational effort and time in the analyses of displacement piles.Geoscience & EngineeringCivil Engineering and Geoscience
Prediction of Molecular Structures Of DDT Dehydrohalogenase and Docking
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
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