• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 83
  • 56
  • 29
  • 9
  • 4
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 201
  • 43
  • 18
  • 16
  • 16
  • 15
  • 14
  • 14
  • 13
  • 12
  • 11
  • 11
  • 10
  • 10
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Synchrotron radiation study of free and adsorbed organic molecules

Zhang, Teng January 2016 (has links)
In this licentiate thesis, organic molecules, namely Cobalt Phthalocyanine (CoPc) and Biphenylene, have been studied by means of synchrotron radiation-based spectroscopic methods (Photoemission Spectroscopy (PES) and X-ray Absorption Spectroscopy (XAS) in combination with Density Functional Theory (DFT) calculations. Paper I is a combined experimental and theoretical investigation of electronic structure of CoPc. addressing the atomic character of the Highest Occupied Molecular Orbital (HOMO) and the electronic configuration of the molecular ground state. Both these aspects are still under discussion since different experimental and theoretical studies have given controversial results. Previous works have indicated the CoPc ground state to either be described by the 2A1g or 2Eg, or by a mix of the two electronic configurations. Regrading the debated the atomic character of the HOMO of CoPc, it has been suggested to be either metal 3d-like and localized on the central Co atom or originating in the organic ligand of the molecule. In this thesis the valence photoemission results for CoPc in gas phase and as adsorbed films on Au(111) together with the DFT simulations, consistently indicate that the HOMO is derived only by the organic ligand, with mainly contribution from the carbon atoms with no metal character. Moreover, the good agreement between the experimental and theoretical results, confirms that the ground state of CoPc is correctly described by the 2A1g configuration. In Paper II, PES and XAS have been used to investigate the occupied and empty density of states of biphenylene films of different thicknesses, deposited onto a Cu(111) crystal. The results have been compared to previous gas phase spectra and single molecule Density Functional Theory (DFT) calculations to get insights into the possible modification of the molecular electronic structure in the film induced by the adsorption on a surface. Furthermore, XAS measurements allowed the characterizion of the variation of the molecular arrangement with the film thickness and helped to clarify the substrate-molecule interaction.
142

Facteurs psychosociaux liés aux risques d'infections virales (VIH/sida et hépatites) chez les cocaïnomanes

Vincent, Martine January 2003 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.
143

Porovnání postojů žáků ZŠ a SŠ k velkým šelmám zejména pak k vlku obecnému (Canis lupus) a psu domácímu (Canis lupus familiaris) / Comparison of Attitudes of Primary and Secondary Schools Students to Large Carnivores, Especially the Common Wolf (Canis lupus) and Domestic Dog (Canis lupus familiaris)

Mejzr, Martin January 2012 (has links)
Today, the issues related to the presence of bears and wolves in the Czech Republic are more frequently discussed due to their occasional occurrence. The significant part of the public still considers these predators dangerous and they even think that a man is supposed to be their potential prey. A lot of surveys confirming this have been already taken, but none of them was focused on the views of primary and secondary schools students. As they are a part of the school education system, their views on the large carnivores should be mainly shaped by it. A questionnaire-based survey was used to find the attitudes of students. The first part of the questionnaire focused on the students' opinions about the dangerousness of predators, its reasons and common wolf presence in the Czech Republic. The second part of the questionnaire is focused on the domestic dog, which has wolf origins. It deals mainly with the attitudes of students to selected dog breeds, dog domestication awareness and views on the so- called "fighting breeds". This work has been aimed at identification of attitudes of the primary and secondary school students from different regions of the Czech Republic to the selected predators. The survey was also taken at primary schools in the High Tatras Mountains, an area where all the large...
144

Pes v českém jazykovém obrazu světa / The Dog in Linguistic Picture of the World in Czech

Prokšová, Hana January 2011 (has links)
I. Abstract This paper is based on the theoretical principes of the Polish ethnolinguistic works introduced in the first part of this paper. We pay special attention to the theory of anthropocentrism of a natural language. The main focus of this theory is the differentiation between "one's own" and "human" on one side and "someone else's" and "non-human"on the other in a cognitive comprehension of the world. We further apply the anthropocentric approach to outline the conceptualization of domestic animals in the Czech language. The second part of the text deals with the expression pes (‚dog') in Czech and its derivatives, their position within the lexical system, their semantics, connotations and the stereotypes associated with them. The conclusion presents a cognitive definition of the concept pes (‚dog') in Czech. The definition builds upon the entry structure of the Polish Dictionary of Folk Stereotypes and Symbols.
145

Metodologická studie setření změn mechanických vlastností kolagenních tkání u pes equinovarus congenitus / Methodological study of changes in mechanical properties of collagen tissues from pes equinovarus congenitus

Červený, Gustav January 2017 (has links)
The goal of this thesis was to invent and perform a testing protocol, witch can detect connective tissue mechanical and structural properties simultaneously in patients with clubfoot. Based on literature findings, it was presumed that connective tissue differ between medial and lateral side of foot. Because of low availability of specimen, it was important to draw and mention crucial alterations of testing protokol, for minimization of failed measurments. For reasons above, two specimens diveded into two samples was used for experiment. Described and discused methodics may enable of reader to insigt to drawbacks of this examination. For usability of this protocol, a setting and testing of few hypotheses was performed. One axis tensial testing with SHG microscopy examination was used in combination for experiment. One of the main result was finding, that structural differencies witch were expected, were not distinctive in samples in untensioned state. But, distingtive differencies may be drawed in tensioned samples. This differences for low number of specimen, cannot show any tendence. Results of tensial testing showed, that samples from medial side of foot can have higher toughness and higher fragility. For future acquisition of tendencies in specimen differencies, it is important to set particular...
146

Como andam os pés dos idosos... Dificuldades e repercussões

Nagy, Istvan 23 October 2006 (has links)
Made available in DSpace on 2016-04-27T18:47:21Z (GMT). No. of bitstreams: 1 GER - Istvan Nagy.pdf: 325846 bytes, checksum: 9149d8cbe8d3b35e04886f589a1b5a54 (MD5) Previous issue date: 2006-10-23 / The general purpose of this investigation is to search for parallels between the causes of some of the most important physical, psychic and behavioral problems of old age and those of foot deformities. The extent to which such foot abnormalities exert an influence on the quality of life of aged people has a direct bearing on the matter under discussion. This study aims at gathering supporting evidence for the analysis of the obstacles old people face in their social commitments when they have defective feet to cope with. Aging entails deleterious anatomical and physiological changes characterizing distinct diseases, which include those affecting the feet. This can cause people to keep away from socio-cultural activities. The feet do not usually receive the same attention as other parts of the body until callosities or odors start to bother. Old people only mention their feet when these are hurting. However, it is nonsensical to keep such problems hidden within the shoes. There are clinical and surgical interventions which can correct one s way of walking and even adjust the anatomical position of the toes. Thus, old people should seek help from health professionals to prevent any worsening of the condition of their feet, which often give us the first indications of serious medical conditions such as the arthritis, diabetes, nervous system and circulation problems. Morphological or physiological alterations occurring in people can, over the long run, involve undesirable consequences in connection with behavior, intellectual ability and physical capacity to proceed with their normal activities. In such cases the feet obviously play, directly or indirectly, an important role in one s eventual inclusion or exclusion in groups which could promote social interactions. After all, as aged people restrict their movements, they start a vicious cycle: reduced activities (sedentary life) lead to muscular atrophy, weakness of the legs and consequently the avoidance of social activities. To solve the problem of the insertion of old people in the social context, the help of health professionals, including physiotherapists, gerontologists, and clinicians amongst others, is essential. Such professionals should harmoniously cooperate to reach a common objective. Some kinds of implements are used to successfully fulfill the purposes which are a good quality of life and longevity / Esta pesquisa tem por objetivo geral confrontar as causas e conseqüências das principais alterações físicas, psíquicas e comportamentais desencadeadas pelas deformidades e patologias que afetam os pés dos idosos. Ao mesmo tempo refletir sobre a qualidade de vida das pessoas que têm distúrbios nos pés. Esse trabalho busca um suporte de análise das dificuldades que as pessoas idosas enfrentam nos compromissos sociais, em virtude das más condições dos seus pés. É pertinente ao assunto, inserir os aspectos do envelhecimento e a sua relação com as diversas doenças, dentre elas, os problemas com os pés que em alguns casos podem afastar o idoso de suas atividades socioculturais. Normalmente, os pés não recebem a mesma atenção que outras partes do corpo até que um calo ou odores comecem a incomodar. Além disso, o idoso só fala dos seus pés quando eles doem. Não é necessário esconder o problema dentro do sapato, uma vez que há tratamentos e intervenções que trazem cura, corrigem os passos e até ajustam a posição anatômica dos artelhos. Outro aspecto importante é que o idoso deve ser atendido por um especialista, para que os pés não fiquem em más condições. Os problemas com nossos pés podem ser os primeiros sinais de condições médicas mais sérias tais como: as artrites, diabetes, e desordens do sistema nervoso e da circulação. Qualquer alteração de caráter morfológico e fisiológico que ocorre no organismo vivo, ao longo do tempo, traz consigo reflexos no comportamento, na habilidade intelectual e na capacidade física de cumprir com as atividades diárias. Nesses eventos estão incluídos, obviamente, os pés que direta ou indiretamente vão interferir nas interações sociais (exclusão/inclusão) do indivíduo. À medida que o idoso vai se restringindo nos seus movimentos entra num círculo vicioso que provoca a diminuição das atividades (sedentarismo) o que vai leválo à atrofia muscular, ao enfraquecimento das pernas e conseqüentemente ao isolamento das atividades sociais. As soluções para a inserção de idosos no contexto social dependem de interatividades profissionais como a gerontologia, a clínica médica e a fisioterapia, dentre outras, que devem cooperar harmonicamente para atingir objetivos comuns. Implementos de várias naturezas, utilizados por equipes, preparadas para isso, tornarão bem-sucedida uma existência, em termos de longevidade e qualidade de vida
147

Structure électronique des hétérocycles BN-aromatiques / The electronic structure of BN-aromatic heterocycles

Maziere, Audrey Alexandra 18 July 2014 (has links)
Depuis leurs découvertes dans les années 60 par Dewar, les composés BN-hétérocycliques ont subi un développement croissant, s’accentuant pendant la dernière décennie. Ce travail de thèse mené en collaboration avec le Pr S-Y LIU de Boston Collège (États-Unis) et le Pr L. WEBER de l’Université de Bielefeld (Allemagne), a permis la synthèse, ainsi que la caractérisation par spectroscopie photoélectronique à rayonnement UV de nouveaux systèmes. Dans une première partie représentée par les chapitres II, III et IV, nous abordons l’étude de la structure électronique des composés suivants : 1,2-dihydro-1,2-azaborine (1), N-Me-1,2-BN-toluene (2), N-Me-1,3-BN-toluene (3), 1,2-dihydro-1-aza-2-boranaphtalene (4), 1,2-dihydro-1-aza-2-boranthracene (5), 1,2-dihydro-1-aza-2-boranthracene (6), 1,2-dihydro-1-aza-2-boraphenanthrene (7), 1,3,2-benzodiazaborole (8), 1,9,8-benzodiazaborole (9), N-tert-butyl[1,3,2]diazaborolo[1,5-a]-pyridine (10), 1,3,2-trihydro[1,3,2]diazaborolo[1,5-a]-pyridine (11). Afin de compléter les propriétés physico-chimiques de ces nouveaux systèmes et d’aider à l’interprétation des spectres photoélectroniques, l’utilisation de calculs quantiques tels que la théorie de la fonctionnelle de la densité (DFT), la théorie fonctionnelle de la densité en fonction du temps (TD-DFT), la fonction de Green (OVGF), la méthode du troisième ordre partiel (P3), ou encore l’interaction de configuration (SAC-CI) ont été utilisées. Dans le Chapitre V, nous présentons une étude comparative entre les énergies ionisations théoriques et expérimentales. / Since the Dewar’s discovering in 60 years, the BN-heterocycles has experienced an important development during the last decade. This thesis presents our work on the synthesis and on the electronic structure characterization by Ultra-Violet photoelectron spectroscopy (UV-PES), followed in collaboration with the Pr SY LIU from the Boston College (USA) and the Pr L. WEBER from the University of Bielefeld (Germany). The first part corresponding to the chapter II, III and IV, describe the electronic structure analysis of: 1,2-dihydro-1,2-azaborine (1), N-Me-1,2-BN-toluene (2), N-Me-1,3-BN-toluene (3), 1,2-dihydro-1-aza-2-boranaphtalene (4), 1,2-dihydro-1-aza-2-boranthracene (5), 1,2-dihydro-1-aza-2-boranthracene (6), 1,2-dihydro-1-aza-2-boraphenanthrene (7), 1,3,2-benzodiazaborole (8), 1,9,8-benzodiazaborole (9), N-tert-butyl[1,3,2]diazaborolo[1,5-a]-pyridine (10), 1,3,2-trihydro[1,3,2]diazaborolo[1,5-a]-pyridine (11). In order to provide more information on the physical chemistry properties and to interpret the photoelectron spectra, the quantum chemical calculations of ionization energies have been followed using the Density Functional Theory (DFT), the Time-Dependent Density Functional Theory (TD-DFT), the Outer Valence Green’s Function (OVGF), the Partial third order (P3), the Symmetry Adapted Cluster-Configuration Interaction (SAC-CI). Moreover, the comparative analysis of theoretical and the experimental ionization energies are presented.
148

Kanaanský pes a využití psa ve vzdělávání / Canaan Dog and Dog Assistant Education

Rutová, Šárka January 2019 (has links)
The topic of this thesis is Canaan dog including dog assistant education. The first part is theoretical and introduces the reader to the Canaan dog breed. The origin of this rare and very old breed is Izrael and first dogs were imported to the Europe and America in 60s of 20th century. The lack of Canaan dogs in Europe causes problems with breeding and transmission of genetic diseases. Especially in the Czech republic there is only few dogs. The teoretical part introduces a transmission of genetic diseases and other diseases. The practical part is focused on a creation of a genealogy of Canaan dogs in the Czech republic. Further I studied inbreeding. In the second part I studied the use of dog in education. The practical part are two education programs, which I created. The first training program is about dogs behaviour, it's also tested in practice and its completed results are part of the appendix. Pupils will learn important information about dogs, how to handle and understand a dog or information about a primitive breed like rare Canaan dog. The second education program is designed for high school students. The program is about inbreeding and includes text and worksheet. Key words: Canaan dog, genetic, heritage, genetic diseases of dogs, inbreeding, animal assistant education.
149

Morpho-physiological bases of spike fertility under contrasting nitrogen availability in durum wheat

Ferrante, Ariel 27 February 2012 (has links)
Current trends in population growth suggest that global food production is unlikely to satisfy future demand under predicted climate change scenarios. Therefore, further improvements on wheat yield potential will be essential to meet future food demand. Thus, to further raise wheat grain yield it is critical to understand the physiological basis of grain number per m2 determination. Yield responsiveness to resource availability is usually related to grain number per m2 in most of grain crops, such as durum wheat. Under Mediterranean conditions, wheat yields vary widely, mainly in response to erratic rainfall, but it has been proposed that part of this variability may be reduced through nitrogen (N) management. Wheat yield responses to N fertilisation are usually related to those of grains per m2, which in turn is the consequence of processes related to floret development (floret initiation followed by floret death/survival) during stem elongation. However, there are almost no studies published relating floret primordia generation and survival in response to increases in N availabilities in wheat. Understanding the dynamics of floret primordia development as a physiological determinant of grain setting can be relevant to further increase grain yield in wheat. The focus of this thesis was to study the effects of N availability and the differences among modern cultivars (and, in some cases, combined with availability of other resources) on dynamics of floret development and survival determining the fate of these primordia and the generation of grain number in durum wheat. Six experiments were conducted (4 semi-controlled and 2 field conditions) during four consecutive growing seasons at Catalonia, NE Spain, with a combination of different N and water availabilities and contrasting modern durum wheat cultivars. Across all experiments, yield responsiveness to N was, in general, related to grain number increases as an indirect response to N through its effect on increasing growth. This is not only based on the fact that the relationship of grain number with spike dry matter was not improved if spike N were used instead, but also on the fact that detillering did increased grain number through the same relationships to spike dry matter. Also, improved spike fertility was due to both producing more fertile florets (in response to N and water or to the removal of competing shoots) and to reduce the percentage of failure of fertile florets in becoming grains. Responsiveness of the number of fertile florets was determined by a developmental response of floret primordia, which under high resource availability conditions continued developing normally in some distal florets of the spikelets, at any position of the spike, whilst in more stressful conditions their development stopped. Genotypic variation in fruiting efficiency was found for modern durum wheat cultivars and there was a tendency for some cultivars to have higher values of fruiting efficiency in most of the environments. Differences in fruiting efficiency were responsible for genotypic differences in grain number. A functional negative relationship was found between grain weight and fruiting efficiency, revealing a trade-off related to spike growth per floret developing normally.
150

Organic Modified GaAs Schottky Contacts

Park, Sung Gook 30 January 2002 (has links) (PDF)
Bibliografische Beschreibung, Referat und Schlagwörter M.S. Chem. Ing. Sung Gook Park Thema: Organic Modified GaAs Schottky Contacts Einreichungsdatum: 28. September 2001 Im Rahmen dieser Arbeit wurden organische Halbleitermaterialien verwendet, um damit die Transporteigenschaften von Metal/GaAs(100) Schottky-Kontakten zu kontrollieren. Ziel ist es, Strom-Spannungs- (J-V) und Kapazitäts-Spannungs-Kennenlien (C-V) zu verstehen. Zur chemischen und elektronischen Charakterisierung der GaAs(100)-Oberflächen, organische Molekül/GaAs(100)-Grenzflächen und der Metall/organische Molekül-Grenzflächen wurden die Photoelektronenspektroskopie (PES) und Nahkantenröntgenabsorptionsspektroskopie (NEXAFS) eingesetzt. Verschiedene GaAs(100)-Oberflächen, wie die reine GaAs(100)-c(4x4)-, die Wasserstoff-Plasma behandelte GaAs(100)- und die chalkogenpassivierte GaAs-Oberflächen, wurden als Substrate für die organische Molekularstrahldeposition (OMBD) verwendet. In der Arbeit wird der Einfluss der chemischen und elektronischen Eigenschaften dieser Substratoberflächen auf das Wachstum von organischen Molekülen auf deren Oberflächen untersucht. 3,4,9,10-Perylentetracarboxylic Dianhydrid (PTCDA) und Dimethyl-3,4,9,10-Perylentetracarboxyl Diimid wurden zur organischen Modifizierung von Metall/GaAs(100)-Schottky-Kontakten verwendet. Die organischen Moleküle werden anfänglich an Defekten der GaAs(100)-Oberflächen adsorbiert. Die Adsorption an Defekten führt zu einer Reduktion der inhomogenen Bandverbiegung der GaAs(100)-Oberfläche. Aus den PES-Spektren wurden Energiebanddiagramme für organische Schicht/GaAs(100)-Grenzflächen und Metall/organische Grenzflächen abgeleitet. Entsprechend der relativen energetischen Lagen des Leitungsbandminimums von GaAs(100)-Oberflächen und des niedrigsten unbesetzten Molekülorbitals der organischen Schichten werden Interfacedipole ausgebildet. Die Verwendung von anorganischen Substraten mit systematisch variierender Elektronenaffinität (EA) stellt eine neue Methode zur Bestimmung des Transportniveaus von Elektronen in der organischen Schicht dar. Bei Einfügung von dünnen PTCDA-Schichten zwischen Ag-Elektrode und GaAs(100)-Oberfläche, wurde beobachtet, dass die J-V-Kennlinien in Abhängigkeit von der Dicke der organischen Schicht und der Behandlung der GaAs-Oberflächen systematisch variierte. Dieses Verhalten kann unter Verwendung des Energieniveaudiagramms, das mittels PES bestimmt wurde, und durch eine Barrierenerniedrigung infolge von Bildkräften gut erklärt werden. Durch die Kombination von Oberflächenbehandlung und Einfügen einer dünnen definierten organischen Schicht kann die effektive Barrierenhöhe in einem breiten Bereich verändert, d. h. letztendlich definiert eingestellt und kontrolliert werden. Daraus ergibt sich die Möglichkeit, die Leistungsaufnahme von GaAs-Schottky-Kontakten zu reduzieren. <Schlagwörter> Organische Moleküle, Organische Molekularstrahldeposition (OMBD), GaAs(100), Metall/Hableiter- Schottky-Kontakt, Photoemissionspektroskopie (PES), Nahkantenröntgenabsorptionsspektroskopie (NEXAFS), Elektrische Messungen

Page generated in 0.1093 seconds