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Déposition des molécules de ferrocène sur une surface de Cu(111) et modifications des états d'interfaces à la suite d'une déposition d'atomes métalliques : étude par dynamique moléculaire par premiers principes / Ferrocene molecular deposition on Cu (111) surface and the interface states after deposition of metal atoms : first principles molecular dynamics studyMbongo Djimbi, Duval 12 October 2012 (has links)
Dans cette thèse, l'étude de la dépostion des molécules de ferrocène sur un substrat de Cu(111) par des simulations de dynamique moléculaire par premiers principes, en particulier, la dynamique moléculaire utilisant l'approche de Born-Oppenheimer (BOMD: Born-Oppenheimer Molecular Dynamics) et celle utilisant la fonctionnelle de l'énergie libre (FEMD: Free Energy Molecular Dynamics), combinées avec les études expérimentales par microscopie à effet tunnel (STM) à basse température et à courant constant ont montré que ces molécules de ferrocène peuvent être physisorbées sur un substrat de cuivre sans donner lieu à une dissociation moléculaire. Ce qui constitue un système idéal pour étudier la dynamique des états d'interfaces et leur réactivité par rapport à la déposition d’atomes métalliques. En particulier, la déposition d'un atome de Cuivre au dessus d'une molécule de ferrocène équilibrée sur le substrat de cuivre, conduit à un transfert de charges de cet atomes vers le substrat de Cu(111). On montre aussi que ces états d'interfaces ont le comportement bidimensionnel d'un gas d'électrons libres. / First-principles simulations studies, in particular Born-Oppenheimer molecular dynamics (BOMD) and free energy molecular dynamics (FEMD), combined with low-temperature scanning tunneling microscopy (STM) and spectroscopy reveal a non dissociative physisorption of ferrocene molecules on a Cu(111) surface, giving rise to ordered molecular layers. At the interface, a 2D-like electronic band is found, which shows an identical dispersion as the Cu(111) Shockley surface-state band. Subsequent deposition of Cu atoms forms charged organometallic compounds that localize interface-state electrons.
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Tech Start-up Internationalisation : Development of an internationalisation model for born global web-based tech start-ups from European start-up hubs / Internationalisering av tech-startups : Utveckling av en internationaliseringsmodell för “born global” webbaserade tech-startups från europeiska startup hubsKoch, Malina January 2017 (has links)
International entrepreneurship is a prominent phenomenon in contemporary research, because of the ease of internationalisation for companies. Start-up hubs in Europe are booming and especially web-based tech companies internationalise quickly. This new type of company, which internationalises almost immediately after foundation, is called born global. Research showed that despite the interest in born global tech start-ups, there is no representative model visualising the process of their internationalisation. Therefore, secondary research is conducted, as well as empirical research in the form of qualitative interviews with three representative, successfully internationalised tech start-ups from Europe. These companies are the music streaming service Spotify, social marketing SaaS Facelift and business management SaaS Ivy. The internationalisation factors resulting from this research can be divided into a preparation phase, possible strategy development and an implementation phase. Within these phases, factors are separated into company- internal and external influences. Based on these findings, a new model on the internationalisation process of web- based tech start-ups is developed. / Internationell entreprenörskap är ett framstående fenomen inom modern forskning eftersom det blir enklare för företag att expandera över nationsgränserna. Startup-hubbar växer fram överallt i Europa och framförallt webbaserade techbolag är snabba med sin internationaliseringsprocess. Det handlar huvudsakligen om en viss typ av företag som kallas för born global, vilket innebär att bolaget börjar sälja sina produkter eller tjänster internationellt direkt efter grundandet. Forskning kring ämnet visar att det finns ett stort intresse för denna typ av företag men inga representativa modeller som visualiserar processen bakom deras internationalisering. Därför genomfördes sekundär forskning samt empirisk forskning i form av tre kvalitativa intervjuer med representanter från framgångsrika och internationella tech startups från Europa. Undersökningen ledde till upptäckten av olika faktorer som påverkar internationaliseringsprocessen. Dessa faktorer kategoriseras som interna eller externa påverkningar på företaget. Internationaliseringsfaktorerna kan delas in i tre faser - förberedelse, möjlig utveckling av strategi och implementering. Baserat på dessa resultat har en modell om internationaliseringsprocessen för born global tech startups utvecklats.
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Vliv sourozenecké konstelace na studijní a profesní aspiraci žáků. / Sibling constellation effects on learning and career aspirations of pupils.KOROTVIČKOVÁ, Blanka January 2012 (has links)
The thesis "Sibling Constellation Effects on Learning and Career Aspirations of Pupils" is aimed at the description of a relationship between birth order and personality development. It also deals with the general characteristics of sibling constellation and its historical development. It points out the importance of sibling constellation in human life and presents the personality description with regard to birth order in relation to parents, siblings, peers, education and occupation. The thesis also involves the research results of birth order effects on learning and career specialization of grammar school pupils. This main part is enriched with the information about the aspiration rate of secondary school and university students. The data were obtained through three similar questionnaires distributed on above-mentioned educational levels during February and March 2012.
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Estudo do método de equalização da eletronegatividade no cálculo de energias livres de solvatação GBEEM-ELR / Study of electronegativity equalization method in the calculation of solvation free energies GBEEM-ELRShimizu, Karina 15 December 2005 (has links)
O método de equalização da eletronegatividade (Electronegativity Equalization Method, EEM), fundamentado em teoria do funcional da densidade eletrônica, foi combinado à aproximação de Born generalizada para moléculas (Generalized Born, GB), e denominado GBEEM (Dias et al., 2002). Os momentos de dipolo permanente no vácuo e em meio condensado (constante dielétrica ~ 80), e distribuições de cargas atômicas, mostraram boa concordância com modelo SM5.4 baseado em cargas CM1 em nível PM3 (12 moléculas, correspondendo a 29 cargas atômicas). Este resultado é interessante devido à simplicidade inerente do GBEEM e seu baixo custo computacional. Uma nova parametrização das durezas e eletronegatividades foi feita com o objetivo de melhorar a distribuição de cargas atômicas em moléculas isoladas em relação ao modelo CM1. Um conjunto de 250 estruturas/cargas PM3/CM1 de moléculas neutras pertencentes a 13 funções orgânicas foi utilizado como alvo na parametrização, utilizando uma metodologia Algoritmo Genético/Simplex de pesquisa de mínimos (Menegon et al., 2002). Boa concordância entre os modelos foi obtida. A validação da parametrização e do EEM foi efetuada usando moléculas bifuncionais (tetrapeptídeo e trisacarídeo) mostrando também boa concordância e robustez. Entretanto, a análise do momento de dipolo permanente das 250 moléculas mostrou uma séria limitação do EEM, e portanto do GBEEM, apesar da boa concordância entre as cargas EEM e CM1. O EEM superestimou os momentos de dipolo. Tal fato pode decorrer de vários fatores, dentre os quais, o truncamento da expansão nas cargas atômicas e ausência de tratamento explícito de interação de troca (exchange). Foi sugerida uma aproximação que restringe a transferência de carga entre grupos na molécula que contornou a limitação do método na predição de momentos de dipolo no vácuo e meio condensado (Shimizu et al., 2004). Com base nos recentes resultados, foi desenvolvido um modelo de solvatação baseado no GBEEM e no modelo de Floris-Tomasi. A calibração foi feita com um conjunto de 62 moléculas neutras (13 grupos funcionais) tendo como alvo as energias livres de hidratação experimentais. Os resultados apresentaram um desvio médio absoluto de 0,71 kcal/mol em relação aos valores experimentais. / The electronegativity equalization method (EEM), founded on density functional theory (DFT), has been combined to the generalized Born approximation (GB) for molecules, and called GBEEM (Dias et al., 2002). The permanent dipole moment in vacuum and condensed phase (dieletric constant ~ 80), and atomic charges distributions, have shown good agreement with SM5.4 solvation model based on CM1 charges at PM3 level (12 molecules, corresponding to 29 atomic charges). This result is interesting due the simplicity of GBEEM and its low computational cost. A new parameterization of the hardness and electronegativities was done with the aim to improve the atomic charges distribution on isolated molecules in comparison to CM1 model. The training set with 250 PM3/CM1 structures/charges of neutral molecules in 13 different organic functions was employed as target in the parameterization. A new optimization approach composed of Genetic and Simplex algorithms was used to fit parameters (Menegon et al., 2002). Good agreement between the models was found. The validation of parameterization and EEM was done using bifunctional molecules (tri-glucose and tetra-peptide) showing good agreement and robustness. However, analysis of permanent dipole moments of 250 molecules shown a serious caveat of EEM and GBEEM, beside the good agreement between EEM and CM1 charges. EEM has overestimated the dipole moments. Such result may be due to the truncated expansion in atomic charges and lacking of explicit treatment of exchange interaction. A new approximation was proposed constraining the charge transfer between groups within the molecule. This approximation corrected the caveat of EEM in the prediction of dipole moments in vacuum and condensed phase (Shimizu et al., 2004). Based on these results, a new solvation model was developed founded in GBEEM and Floris-Tomasi model. The parameterization was done with a training set of 62 neutral molecules (13 functional groups) and experimental hydration free energies as target. This new solvation model has produced a mean absolute deviation, MAD, of 0.71 kcal/mol comparing to experimental data.
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Att upprätthålla livet : Om lågavlönade ensamstående mödrars försörjning i Sverige / Supporting livelihood : Low-paid single mothers’ sustenance in SwedenYazdanpanah, Soheyla January 2008 (has links)
This dissertation is about the experiences of low-paid single mothers in sustaining their families in Sweden in the early 2000. The investigation builds upon interviews with twenty low-paid single mothers living and working in Stockholm. Ten of the women are Swedish-born and the other ten are Iranian-born but have been residing in Sweden for several years. A majority of the Swedish-born women belong to the working class, while most of the Iranian-born mothers are from a middle class background. This study is based on an extended definition of sustenance that encompasses support for livelihood and meeting the family needs that conform to socially accepted norms. Sustenance requires incomes to cover expenses and care work. The informants sustain their families mostly from wage work. However, they also seek allowances from the social security system to buy goods and services that they combine with care work to sustain the family. The care work for younger children demands much time and physical work, while caring for older children requires more mental and emotional work. Sustenance for these mothers implies fulfilling all these demands and also to ensure that the children’s’ needs are met. Several factors influence the mothers’ sustenance. Low wages and the single responsibility for children means less money and more time devoted to care work. Few fathers take significant responsibility for their children’s sustenance. The mothers get support from their social networks, often from other women and from the welfare system. Ethnic background negatively affects sustenance for the Iranian-born mothers mostly in the form of reduced cultural and social capital. Children are the highest priority among all the families. However, the priorities may differ among the families and are connected to the mothers’ class, ethnic background and their access to cultural capital.
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Business in the Cloud : Internationalization of a small enterprise in the age of cloud servicesSeverin, Mats, Knutsson, Stefan, Söderberg, John January 2012 (has links)
During the past decade, advances in information technology have facilitated the rapid international expansion of small and medium-sized enterprises (SMEs). Cloud computing has enabled a new wave of firms to offer services on the web regardless of geographic distances. The aim of this study is to explore how cloud computing affect the external variables network and culture in the internationalization process of an SME. In order to explore the impact on these external variables, a qualitative case study is carried out on a business-to-business SME offering cloud services within small and open economies. The findings explain why closeness was important and why the cloud service firm was limited to a gradual internationalization process although the technology has the potential to break this pattern or accelerate it. The results from this study are valuable for scholars since the internationalization process of cloud service firms is an under-researched area. It is also useful for cloud service SMEs when making strategic decisions in the internationalization process.
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Internationalisering av Born Global-företag : En studie om bakomliggande faktorer vid internationalisering av Born Global-företag / Internationalization of Born Global firms : A study of underlying factors to the internationalization of Born Global firmsMihai, Gabriela, Ståhlberg, Jonas, Kayhan, Sümeyra January 2010 (has links)
Purpose: The purpose of this study is to find out how much influence underlying factors have in connection to the internationalization of Born Global firms. Methodology: This study has a qualitative approach in which data is obtained mainly through interviews and secondary data which consists previous theories about the internationalization in small and medium sized firms and recent theories that entitle these firms as Born Global. Conclusion: Based on the existing theories and the qualitative data, we have concluded that the underlying factors for the Born Global firm’s internationalization are abilities and opportunities to create insidership in relevant networks. The most crucial underlying factors for Born Global firm’s internationalization are the ability to create processes to break old patterns of thoughts and the ability to ally with right partners. / Syfte: Syftet med denna uppsats är att ta reda på hur stor påverkan olika bakomliggande faktorer haft i samband med en internationalisering av Born Global-företag. Metod: Denna studie är av kvalitativ ansats där data har samlats in främst genom djupintervjuer och av tidigare teorier om små- och medelstora företags internationalisering samt senare teorier som benämner dessa företag som Born Global. Slutsats: Vi har utifrån befintliga teorier och empiri kommit fram till att bakomliggande faktorer som personliga förmågor och möjligheter behövs för att kunna skapa innanförskap i relevanta nätverk. De mest avgörande bakomliggande faktorerna för Born Global-företags internationalisering är förmågan att kunna skapa processer för att bryta invanda tankemönster samt förmågan att alliera sig med rätt partners.
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Estudo do método de equalização da eletronegatividade no cálculo de energias livres de solvatação GBEEM-ELR / Study of electronegativity equalization method in the calculation of solvation free energies GBEEM-ELRKarina Shimizu 15 December 2005 (has links)
O método de equalização da eletronegatividade (Electronegativity Equalization Method, EEM), fundamentado em teoria do funcional da densidade eletrônica, foi combinado à aproximação de Born generalizada para moléculas (Generalized Born, GB), e denominado GBEEM (Dias et al., 2002). Os momentos de dipolo permanente no vácuo e em meio condensado (constante dielétrica ~ 80), e distribuições de cargas atômicas, mostraram boa concordância com modelo SM5.4 baseado em cargas CM1 em nível PM3 (12 moléculas, correspondendo a 29 cargas atômicas). Este resultado é interessante devido à simplicidade inerente do GBEEM e seu baixo custo computacional. Uma nova parametrização das durezas e eletronegatividades foi feita com o objetivo de melhorar a distribuição de cargas atômicas em moléculas isoladas em relação ao modelo CM1. Um conjunto de 250 estruturas/cargas PM3/CM1 de moléculas neutras pertencentes a 13 funções orgânicas foi utilizado como alvo na parametrização, utilizando uma metodologia Algoritmo Genético/Simplex de pesquisa de mínimos (Menegon et al., 2002). Boa concordância entre os modelos foi obtida. A validação da parametrização e do EEM foi efetuada usando moléculas bifuncionais (tetrapeptídeo e trisacarídeo) mostrando também boa concordância e robustez. Entretanto, a análise do momento de dipolo permanente das 250 moléculas mostrou uma séria limitação do EEM, e portanto do GBEEM, apesar da boa concordância entre as cargas EEM e CM1. O EEM superestimou os momentos de dipolo. Tal fato pode decorrer de vários fatores, dentre os quais, o truncamento da expansão nas cargas atômicas e ausência de tratamento explícito de interação de troca (exchange). Foi sugerida uma aproximação que restringe a transferência de carga entre grupos na molécula que contornou a limitação do método na predição de momentos de dipolo no vácuo e meio condensado (Shimizu et al., 2004). Com base nos recentes resultados, foi desenvolvido um modelo de solvatação baseado no GBEEM e no modelo de Floris-Tomasi. A calibração foi feita com um conjunto de 62 moléculas neutras (13 grupos funcionais) tendo como alvo as energias livres de hidratação experimentais. Os resultados apresentaram um desvio médio absoluto de 0,71 kcal/mol em relação aos valores experimentais. / The electronegativity equalization method (EEM), founded on density functional theory (DFT), has been combined to the generalized Born approximation (GB) for molecules, and called GBEEM (Dias et al., 2002). The permanent dipole moment in vacuum and condensed phase (dieletric constant ~ 80), and atomic charges distributions, have shown good agreement with SM5.4 solvation model based on CM1 charges at PM3 level (12 molecules, corresponding to 29 atomic charges). This result is interesting due the simplicity of GBEEM and its low computational cost. A new parameterization of the hardness and electronegativities was done with the aim to improve the atomic charges distribution on isolated molecules in comparison to CM1 model. The training set with 250 PM3/CM1 structures/charges of neutral molecules in 13 different organic functions was employed as target in the parameterization. A new optimization approach composed of Genetic and Simplex algorithms was used to fit parameters (Menegon et al., 2002). Good agreement between the models was found. The validation of parameterization and EEM was done using bifunctional molecules (tri-glucose and tetra-peptide) showing good agreement and robustness. However, analysis of permanent dipole moments of 250 molecules shown a serious caveat of EEM and GBEEM, beside the good agreement between EEM and CM1 charges. EEM has overestimated the dipole moments. Such result may be due to the truncated expansion in atomic charges and lacking of explicit treatment of exchange interaction. A new approximation was proposed constraining the charge transfer between groups within the molecule. This approximation corrected the caveat of EEM in the prediction of dipole moments in vacuum and condensed phase (Shimizu et al., 2004). Based on these results, a new solvation model was developed founded in GBEEM and Floris-Tomasi model. The parameterization was done with a training set of 62 neutral molecules (13 functional groups) and experimental hydration free energies as target. This new solvation model has produced a mean absolute deviation, MAD, of 0.71 kcal/mol comparing to experimental data.
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Vliv pořadí sourozenců v rodině pro nasměrování profesní orientace. / The impact of order of siblings on the choice of profession.HEJLKOVÁ, Kristýna January 2007 (has links)
In my paper I would like to focus on comparing of two groups of siblings in a different sibling positiron and their presisposition for the choice of the occupation and point out the qualities that an individual carries from the childhood and which can influence the choice of their future occupation. I want to make out and compare the changes in this theory in the course of a decade. According to the statistics I have assumed that the firs-bor will choose still occupations demanding accuracy, high conce thein perfectionism and thein will to achieve success. On the contrary, the youngest ones are supposed to be free thinkers and chaose flexible and independent occupations. Both the hypothes have proved true. For collection the date this thesis I use questionnaire. It was filled up with randon representatives with different age. I made a research by comparing the representatives of the oldest and the youngest siblings and partially also middle ones.
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Secção de choque total absoluta do espalhamento de elétrons por Metanol e EtanolSilva, Daniel Gustavo Mesquita da 06 April 2009 (has links)
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Previous issue date: 2009-04-06 / Neste trabalho foram obtidas Secções de Choque Totais Absolutas (SCTA) para moléculas de Etanol e Metanol utilizando um aparelho desenvolvido no Laboratório de Espectroscopia Atômica e Molecular do DF/UFJF, que emprega a técnica de transmissão linear. As medidas foram realizadas para o Metanol e Etanol cobrindo as energias de impacto de 70, 80, 90, 100, 150, 200, 250, 300, 350, 400 e 500 eV e também de 60 eV para o Etanol. A resolução de energia em todas as medidas foi de 0,6 eV (FWHM) e a incerteza no cálculo das SCTs foi estimada em 5%. A faixa de pressão na célula de espalhamento foi mantida entre 1 a 4mTorr. Os elétrons que sofreram processos de colisões inelásticas podem ser descriminados daqueles que não sofreram nenhum processo de interação com o alvo por um analisador cilíndrico dispersivo 127º, que tem a finalidade de selecionar os elétrons que serão detectados pelo Coletor de Faraday. Medindo a intensidade do feixe de elétrons atenuados, a SCTA pode ser obtida aplicando a Lei de Lambert Beer. Os dados foram obtidos através de um procedimento estatístico envolvendo uma série de 4 a 7 sessões de medidas, os valores obtidos foram utilizados para encontrar a SCT para uma determinada energia definida. Além das medidas experimentais, nós determinamos SCT utilizando a Regra da Aditividade. Nós também avaliamos nossos dados experimentais usando uma fórmula de dois parâmetros (Curva de Born) para cada gás. Nossos dados experimentais concordam com a maioria dos dados publicados na literatura. Não existem dados reportados na literatura de SCT para a molécula do Etanol (C2H5OH). / We have measured the absolute Total Cross Section (TCS) for methanol and ethanol
molecules using an apparatus manufactured at the Molecular Spectroscopy Laboratory at DF/UFJF,
which employ the linear transmission technique. The experimental data were taken at incident
electron energies of 70, 80, 90, 100, 150, 200, 250, 300, 350, 400 and 500 eV for methanol and
ethanol and also of 60 eV for ethanol. The energy resolution in all measurements was 0,6 eV
(FWHM) and the overall systematic uncertainty at the TCS were evaluated to be less than 5%. The
pressure range in the scattering cell was chosen between 1 and 4mTorr. Those electrons which passed the exit orifice of the chamber were discriminated with a 127o cylindrical energy selector
coupled with an entrance set of electrostatic lenses and detected by a Faraday cup. Measuring the
attenuation of intensity of the projectile-particle beam transmitted through the target volume, the
absolute TCS for a given impact energy was derived from the Beer-Lambert law. The
measurements were carried out for a given energy in a series of alt least 4 runs, each one taking at
least 7 values and an averaging procedure was applied to derive the final total cross section at a
particular energy. Besides the experimental measurements, we have additionally determined TCS
using the Additivity Rule. We have also evaluated our experimental data using a fitting procedure
with the Born-like formula containing two parameters for each gas. Our experimental data are in
good agreement with the majority of previous measurements published in the literature. There are
no previous reports of experimental electron scattering Total Cross Section C2H5OH in the
literature.
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