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A study of the style and iconography of Etruscan engraved gemsGlynn, Ruth January 1982 (has links)
This thesis examines the development of the art of gem engraving in Etruria between the years from ca 520 to ca 470 BC. It is divided into two parts, the first of which is an analysis of the style of the intaglios, and the second an analysis of the iconography. In Part One attributions to individual hands or groups are suggested, and conventional names supplied; the relationships of the engravers both to each other and to the late archaic Greek schools are examined. In Part Two the iconography of the intaglios is examined both internally and against the wider background of Etruscan and Greek art;- where relevant, comparison is also made with the literary tradition; this study concerns itself only with the human figure, and the chapters are arranged around cycles of myth and the individual figure types.
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Do national and entrepreneurial framework conditions influence economic growth? : Using path analysis (PA) on the example of Nordic countries between the years 2005-2014Slabenakova, Andrea January 2016 (has links)
This paper investigates whether national and entrepreneurial framework conditions positively affect economic growth via its effects on entrepreneurial activity more significantly than via its effects on technological innovation intensity1 . The revised GEM conceptual model is tested for a sample of Nordic countries (Norway, Finland, Sweden, Denmark, Iceland), between the years 2005-2014, using path analysis. The variables representing national and entrepreneurial framework conditions, entrepreneurial activity, technological innovation intensity and economic growth are Global Competitiveness Index (which includes also number of procedures to start a business and number of days to start a business, venture capital availability etc.), selfemployed workers (expressed as % of total employed), RD expenditures (expressed as % of GDP) and GDP per capita. In each of the models, the author finds out a positive effect of national and entrepreneurial framework conditions. The hypotheses stating the positive indirect influence of national and entrepreneurial framework conditions on economic growth via entrepreneurial activity (H1) and the positive indirect influence of national and entrepreneurial framework conditions via technological innovation intensity (H2) have been accepted. The calculated total effect on economic growth indicates that the path via entrepreneurship (H1) is more significant (H3).
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Theoretical studies and structural analysis of models of surface organometallic centresAdnan, Rohana January 2000 (has links)
No description available.
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Polymer Remodeling Enabled by Covalent MechanochemistryRamirez, Ashley Lauren Black January 2013 (has links)
<p>Material failure is a ubiquitous problem, and it is known that materials fail at much lower stresses than the theoretical maximum calculated from the number and strength of the individual bonds along the material cross-section. The decreased strength is attributed to inhomogeneous stress distributions under load, thus causing the stress to accumulate at localized regions, initiating microcrack formation and subsequent propagation. In many cases, these initiation and propagation steps involve covalent bond scission. </p><p>Over the past decade there has been increased interest in channeling the mechanical forces that typically trigger destructive processes (e.g., chain scission) during use into constructive chemical transformations. In an ideal system, these stress-induced chemical transformations would redistribute load prior to material failure, thus extending material lifetime. In this Dissertation, the work of developing constructive transformations through the response of a small molecule "mechanophore" is discussed. </p><p>The gem-dihalocyclopropane mechanophore is capable of undergoing a non-scissile electrocyclic ring opening reaction under molecular scale tensile load. The mechanochemistry is demonstrated both in solution via pulsed ultrasound (Chapter 2) and in the bulk via extrusion and uniaxial tension (Chapter 3). In solution, dramatic remodeling at the molecular level occurs under the elongational flow experienced during pulsed ultrasound. Because elongational flow results in regiospecific stress distributions along a polymer main chain, this remodeling converts a gem-dichlorocyclopropane-laden homopolymer into phase separating diblock-copolymers. In the bulk, it is shown that the increased reactivity of an activated gem-dibromocyclopropane mechanophore towards nucleophilic displacement reactions leads to more non-destructive intermolecular bond-forming reactions than chain scissions, indicating the potential of the gem-dibromocyclopropane mechanophore as a self-strengthening platform. </p><p>Coupling the idea of mechanophore activation under high forces and covalent bond formation, an autonomous remodeling platform is developed, utilizing the gem-dibromocyclopropane mechanophore and a carboxylate nucleophile (Chapter 4). The system can be either two components, with a mechanophore-based polymer and a small molecule cross-linker, or a one-component system in which the mechanophore and nucleophile are embedded within the same polymer backbone. Both in the bulk and in solution, the autonomous remodeling polymer undergoes mechanophore activation followed by covalent bond formation, creating a cross-linked network in response to high shear forces. This form of remodeling leads to orders of magnitude increases in elastic modulus in response to forces that otherwise degrade polymer molecular weight and material properties. In all cases, the covalent bond formation through nucleophilic displacement of the allylic bromine by a carboxylate is confirmed as the source of polymer remodeling by FTIR as well as numerous control studies. </p><p>Together, these studies show that covalent polymer mechanochemistry can be used as a constructive tool for polymer chemistry (the direct conversion of homopolymers into well-ordered diblock copolymers) and materials science (polymers that self-strengthen in response to an applied force). This work paves the way for the future development of new mechanophores that will optimize the proof-of-principle behaviors demonstrated here.</p> / Dissertation
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Comparing and contrasting the differences between opportunity entrepreneurship and necessity entrepreneurshipMai, Jen-Wen 16 October 2008 (has links)
¡§Global Entrepreneurship Monitor (GEM)¡¨ is a research program initiated in 1999 by Babson College and London Business School. In its research papers, two types of entrepreneurship were mentioned: opportunity and necessity entrepreneurship. The term ¡§opportunity entrepreneurship¡¨ refers to the ones who pursue a business opportunity for personal interest. In contrast, people who reported they were involved in creating a business because they had no better choices for work were referred as ¡§necessity entrepreneurship.¡¨
In 2006, forty-two countries participated in the GEM program. According to the findings from the GEM program, opportunity entrepreneurship and necessity entrepreneurship are different in many aspects. Unfortunately, Taiwan is not one of the countries that are involved. Therefore, the major task of this thesis is to identify the differences between opportunity entrepreneurship and necessity entrepreneurship in Taiwan, focusing mainly on the city of Kaohsiung.
In this research, we will concentrate on finding the differences between the opportunity entrepreneurship and the necessity entrepreneurship. The study will focus on backgrounds, characteristics, and experiences of these two kinds of entrepreneurships. Since this is a quantitative research, a questionnaire will be issue to each of the participants.
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Study of Triple-GEM detector for the upgrade of the CMS muon spectrometer at LHCMaerschalk, Thierry 12 July 2016 (has links)
This doctoral thesis is part of the upgrade of the CMS experiment at the Large HadronCollider of CERN, the LHC. CMS, together with the ATLAS experiment, led to thediscovery of the Brout-Englert-Higgs boson in 2012. But the LHC research program isnot over yet. Indeed, the LHC is intended to operate even at least 20 more years. Duringthis period, the luminosity will grow gradually up to five times its nominal value of 10 34cm −2 s −1 initially foreseen. This increase in luminosity requires the LHC experiments,like CMS, to upgrade their detectors as well as their data acquisition system. One of thenext major CMS upgrade is the addition of a new detector layer in the forward muonspectrometer of CMS. The technology that has been chosen by the CMS collaborationfor this upgrade is the Triple Gas Electron Multiplier (Triple-GEM) technology. Thisupgrade aims to maintain the trigger performance despite the increasing rate of particles(> 1 kHz/cm 2 ) and will also improve the reconstruction of muons tracks, thanks to aexcellent spatial resolution (∼ 250 μm). It is the study and characterization of thistechnology that is the subject of this thesis.This characterization of the Triple-GEM detectors starts with a detailed study of thetime resolution. This study has been performed using different Monte Carlo simulationslike GARFIELD, and has demonstrated that the Triple-GEM detectors equipped withthe new VFAT3 electronics (developed for this upgrade) fulfill the requirements for theCMS upgrade.Then we have studied different detector prototypes. First, we have built two small 10×10cm 2 prototypes and developed a test bench at the ULB laboratory. This test bench hasallowed us to study another important parameter of the Triple-GEM detectors: the gain.Later, we also had the opportunity to take part in the data taking and analysis of a testbeam campaign at CERN. The analysis of the data of this test beam is also presentedin detail.The last part of this work concerns the study of the spatial resolution. We have estimatedthe spatial resolution of the Triple-GEM detector equipped with a binary electronics byMonte Carlo simulations as well as analytically. This study has been extended to otherdetector technologies like the Micromegas and the silicon sensors. / Cette th`ese de doctorat s’inscrit dans le cadre de la mise `a niveau de l’exp ́erience CMSaupr`es du grand collisionneur de protons du CERN, le LHC. CMS, avec l’exp ́erienceATLAS, a permis la d ́ecouverte du boson de Brout-Englert-Higgs en 2012. Mais leprogramme de recherche du LHC n’est pas pour autant termin ́e. En effet, le LHC estdestin ́e `a fonctionner encore au moins 20 ans. Pendant cette p ́eriode, la luminosit ́e vacroˆıtre progressivement jusqu’`a atteindre environ cinq fois la valeur nominale de 10 34cm −2 s −1 initialement pr ́evue et ce d’ici 2025. Cette augmentation de luminosit ́e pousseles exp ́eriences du LHC, comme CMS, `a mettre `a jour les d ́etecteurs ainsi que leurssyst`emes d’acquisition de donn ́ees. Une des prochaines mises `a niveau majeures deCMS est l’addition d’une nouvelle couche de d ́etection dans le spectrom`etre `a muonvers l’avant. La technologie de d ́etection qui a ́et ́e choisie par la collaboration CMS estla technologie des Triple Gas Electron Multiplier (Triple-GEM). Cette mise `a niveaua pour but de maintenir les performances du syst`eme de d ́eclenchement et ce malgr ́el’augmentation de taux de particules (> 1 kHz/cm 2 ) et de permettre ́egalement, grˆacea la tr`es bonne r ́esolution spatiale des Triple-GEM (∼ 250 μm), l’am ́elioration de la re-construction des traces de muons. C’est l’ ́etude des caract ́eristiques de cette technologiequi est le sujet de cette th`ese.Cette caract ́erisation des d ́etecteurs Triple-GEM commence par une ́etude d ́etaill ́ee de lar ́esolution temporelle. Cette ́etude a ́et ́e r ́ealis ́ee `a l’aide de diff ́erentes simulations MonteCarlo telles que GARFIELD et a permis de montrer que les Triple-GEMs ́equip ́es de lanouvelle ́electronique VFAT3 (sp ́ecifiquement d ́evelop ́ee pour les Triple-GEMs) remplis-sent les conditions pour la mise `a niveau de CMS.Nous avons ensuite ́etudi ́e diff ́erents prototypes. Tout d’abord nous avons construit deuxpetits (10 × 10 cm 2 ) prototypes de Triple-GEM et d ́evelop ́e un banc de test au sein dulaboratoire de l’ULB. Ce banc de test nous a permis d’ ́etudier un autre param`etre impor-tant des d ́etecteurs Triple-GEM: le gain. Au cours de cette th`ese nous avons ́egalementparticip ́e `a la prise de donn ́ees et `a l’installation de diff ́erents tests en faisceau au CERN.L’analyse des donn ́ees du test en faisceaux d’octobre 2014 est aussi pr ́esent ́ee en d ́etail.La derni`ere partie de ce travail concerne l’ ́etude de la r ́esolution spatiale. Nous avonsestim ́e la r ́esolution spatiale par simulation de Monte Carlo ainsi que de mani`ere an-alytique pour des d ́etecteurs GEM munis d’une ́electronique binaire. Cette ́etude a ́egalement ́et ́e g ́en ́eralis ́ee `a d’autres d ́etecteurs tels que les Micromegas ou encore lescapteurs au silicium. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
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An investigation of treatment methods of cobalt ore from the Gem mine, Bridge RiverTaylor, Raymond Russell January 1941 (has links)
[No abstract submitted] / Applied Science, Faculty of / Materials Engineering, Department of / Graduate
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Effect of gem-difluorination on the conformation of selected hydrocarbon systemsSkibiński, Maciej January 2014 (has links)
Owing to its unique electronic properties, the CF₂ group has the potential to affect the conformation and polarity of molecules. The Introduction provides an overview of the conformational effects induced by the incorporation of fluorine into hydrocarbons, e.g. gauche effect, 1,3-C,F bond repulsion and angle deviation in organofluorine compounds. A summary of synthetic strategies for the introduction of the gem-difluoride motif into organic molecules is also presented. In order to explore the conformational impact of the CF₂ group in alicyclic hydrocarbon systems, cyclododecane was employed as the molecular framework. In 1,1,4,4- and 1,1,7,7- tetrafluorocyclododecanes, two CF₂ groups replaced CH₂ units within the square [3333] cyclododecane ring where the spacing enables the CF₂ groups to occupy adjacent or opposite corner locations. In the case of 1,1,6,6-tetrafluorocyclododecane, one of the CF₂ groups was forced to the edge position, which changes the ring conformation dramatically. Strategic incorporation of two CF₂ groups is shown to either stabilise or significantly alter the conformation of the cyclododecane framework, a revealing conformational preference of the CF₂ group to locate at the corner rather than the edge position of hydrocarbon rings. The study extends to larger cycloalkanes, rectangular [3434] cyclotetradecanes and square [4444] cyclohexadecanes. The target cycloalkanes bearing two CF₂ units were assembled through a novel synthetic route, employing ring-closing metathesis (RCM) as the key step. X-Ray structure analyses revealed that the CF₂ groups occupy exclusively corner locations of these rings too. The spacing between the CF₂ moieties dictates the overall ring conformations and offers a useful tool for controlling molecular arrangement. An accelerating role of the CF₂ group, relative to the CH₂ group, on the ring-closing metathesis of C5-substituted 1,8-nonadienes has also been studied. Remarkably, the CF₂ group exhibited a similar reaction rate to that observed for nonadienes bearing 1,3-dioxolane or dimethylmalonate groups. This effect was rationalised by the thermodynamic stability of the cycloheptene products, rather than a Thorpe-Ingold effect.
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Síntese de gem-dicloroaziridinas empregando KF/Al2O3 / Synthesis of gem-dichloroaziridine employing KF/Al2O3Meirelis, Francine Paulina 31 March 2014 (has links)
Nos últimos anos, questões ambientais têm merecido destaque na mídia nacional e internacional. A química tem uma grande participação nos dias atuais com os inúmeros produtos fundamentais à humanidade. A sua presença pode ser destacada desde diversos combustíveis aos mais complexos medicamentos. As reações de síntese orgânica devem ser guiadas por novas práticas mais sustentáveis. Nesse campo, tem-se o conceito da Green Chemistry ou Química Verde, que consiste na estratégia em desenvolver metodologias e processos que usem e gerem a menor quantidade de materiais tóxicos e/ou inflamáveis ou reaproveitáveis. Com o intuito de contribuir com a Química Verde, estudou-se a síntese de iminas que consistiu da primeira etapa do processo de aminação livre de solventes orgânicos e apresentaram rendimentos superiores a 95,0 %; gem-dicloroaziridinas foram preparadas a partir de inserção de diclorocarbeno em iminas em condições mínimas de solvente orgânico, utilizando como catalisador o KF/Al2O3 e com rendimentos superiores a 98,0%. As gem-dicloroaziridinas foram convertidas em amidas por hidrolise, na ausência de solvente e com rendimentos superiores a 98,0%. Dentro do conceito de Química Verde foram preparadas as seis iminas: N-benzilfenilmetanoimina, N-fenil-furilmetanoimina, N-fenilfenilmetanoimina, N-fenil-(4-metoxifenil)-metanoimina, N-benzil-(4-metoxifenil)metanoimina e N-furfurilfurilmetanoimina; duas gem-dicloroaziridinas: 2,2-dicloro-1,3-difenilaziridina e 1-benzil-2,2-dicloro-3-fenilaziridina e duas amidas: cloro-fenilacetanilida e N-benzil-cloro-fenilacetamida. / For the last years Environmental issues have deserved featured in the National and International media. Chemistry has had great participation on currently days with countless products which are fundamental to humanity. Its presence can be detached from various fuels to the most complex drugs.The organic synthesis reactions should be guided by more sustainable new practices. In this field, the Green Chemistry concept or (Química Verde) strategy which aims to develop methodology and and/or processes which use and generate the minimum quality of toxic inflammable material. With the purpose of contribute to green chemistry, we studied the synthesis of imines which consisted of the first stage of the process of amination, free of organic solvents and have yields higher than 95%; gem-dichloroaziridine were prepared from the imines insertion dichlorocarbene in a minimum of organic solvent conditions, using as catalyst KF/Al2O3 and yields higher than 98%. The gem-dichloroaziridines were converted to amides by hydrolysis in absence of solvent and yields higher than 98.0%. Within the concept of Green Chemistry were prepared six imines: N-benzyl- phenylmethanimine, N-phenyl-2- furylmethanimine, N-phenyl- phenylmethanimine, N-phenyl-(4-methoxyphenyl)methanimine, N-benzyl-(4-methoxyphenyl)metha-nimine,N-(2-furylmethyl)-2-furylmethanimine; two gem-dichloroaziridinas: 2,2-dichloro-1,3-diphenyla-ziridine and 1-benzyl-2,2-dichloro-3-phenylaziridine and two amides: chlorophenylacetanilide and N-benzyl-chloro-phenylacetamide.
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Entreprenörskap i Sverige och Japan : En komparativ studie utifrån GEM 2007Aaby, Jovanna January 2011 (has links)
Syfte: Syftet med denna studie är att jämföra entreprenörskap i Sverige och Japan och att få en förståelse för varför så olika länder båda har så lågt entreprenörskap. Jag har valt att avgränsa mig till data hämtade från GEM 2007. Metod: I detta arbete gör jag en jämförelse av entreprenörskap i Sverige och i Japan som jag gjort genom att införskaffa sekundär data från en rapport från GEM 2007. I detta arbete har mitt förhållningssätt främst varit abduktivt. Teoretiska Perspektiv: Wennekers (2006) har undersökt den U-kurva som uppstår när man studerar entreprenörskap i relation till ekonomisk utveckling. Länder tenderar att gå från en hög nivå av entreprenörskap till en låg nivå när man går från bondeekonomi till industriell ekonomi för att sedan öka igen när länder nått en avancerad nivå av ekonomisk utveckling. Trots dessa samband så skiljer sig länder fortfarande mycket åt när det kommer till entreprenörskap och förändringarna verkar vara ihållande. Wennekers (a.a.) menar att detta snarare beror på kulturella skillnader än ekonomiska skillnader eftersom kulturella skillnader är relativt oföränderliga över tiden. Empiri: GEM står för Global Entrepreneurship Monitor och är ett not-for-profit akademiskt forsknings konsortium. Deras mål är att göra internationell forskning av hög kvalité om entreprenöriska aktiviteter i världen som kan nå en så bred publik som möjligt. GEMs studie är den största enskilda studie av entreprenörisk aktivitet i världen och startade 1999. I detta arbete har jag använt mig av data från GEMs rapport från 2007 som är det år då både Japan och Sverige var med senast. Resultat: I en jämförelse av Japan och Sverige så hittar jag en del likheter, men främst skillnader. Detta antyder att det inte finns några enkla svar på varför entreprenörskap är lågt i ett land. Resultatet av studien indikerar att de nationella experterna hade rätt när de gav statlig politik som främsta problemområde för Sverige och kultur och sociala normer för Japan. / Purpose: The purpose with this thesis has been to compare entrepreneurship in Sweden and in Japan. It has also been to get a wider understanding why two so different countries both have a low level of entrepreneurship compared to other countries. Since the subject is wide I have chosen to delimitate to data from GEM 2007. Methodology: In this thesis I have compared entrepreneurship in Sweden and in Japan. This I have done by obtaining secondary data from GEM’s report from 2007. My approach in this thesis has foremost been abductive. Theoretical perspectives: Wennekers (2006) have studied the U-shape curve that occurs when you put entrepreneurship in relation to economic growth. Countries tend to go from a high level of entrepreneurship to a low level when they go from agricultural economy to an industrial economy. Then they tend to go up again when they reach a advanced level of economic development. However countries seem to differ when it comes to entrepreneurship despite this relation and the differences seems to be lasting. Wennekers (a.a.) believe that these differences has to do with cultural differences rather than economics differences since cultural differences are relatively immutable over time. Empirical foundation: GEM stands for Global Entrepreneurship Monitor and is a not-for-profit academic research consortium. Their goal is to make international research of high quality about entrepreneurial activity in the world that is able to reach a wide public. GEM’s study is the biggest study in the world about entrepreneurial activity and started 1999. In this thesis I have used data from GEM’s report from 2007, which is the latest report with both Sweden and Japan. Conclusions: In a comparison between Japan and Sweden I have found some similarities but mostly differences. This suggests that there are no simple answers to a low level of entrepreneurship in a country. However, in my opinion, I think that the national experts were right to put government policies as the biggest problem for Sweden and Cultural, Social norms as Japan’s biggest problem.
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