Hintergrund: Elastischer Ohrknorpel ist eine potentielle Quelle fuer autologe Zellen um die luminalen Oberflaechen von links ventrikularen assist systemen (LVAD''s) zu besiedeln zu dem Zweck die Biokompatibilitaet dieser Systeme zu verbessern. Wir prueften dieses Potential der Ohrknorpelzellen in vitro und in vivo in einem Tiermodel (Kalb). Methoden: In vitro, Elastischer Knorpel wurde von dem Ohr eines Kalbes unter Lokalanaesthesie gewonnen, isoliert, und in Gewebekultur gezuechtet. Chondrocytes wurden immunocytochemisch analysiert, transferriert in Zellkulturmedium, zweimal umgesetzt, und auf die blutkontaktierenden, luminalen Oberflaechen von vier LVAD''s (HeartMate(R); Thermo Cardiosystems, Inc., Woburn, MA) gesiedelt. Die beschichteten Zelloberflaechen wurden preconditioniert unter Flussbedingungen in vitro, um die Zellhaftung an den luminalen Oberflaechen der LVAD''s zu beguenstigen. Die Effiezienz der Zellbesiedelung und der kumulative Zellverlust unter Flussbedingungen in vitro wurden quantifiziert. In vivo, eine der vier chondrocyte-beschichteten und preconditionierten LVAD''s wurde in das Kalb implantiert, welches urspruenglich Ohrknorpelspender diente. Das LVAD wurde fuer sieben Tage betrieben, dann explantiert und pathologisch und histologisch evaluiert unter der Benutzung eines Scanningelektronenmikroskopes und eines Transmissionelektronenmikroskopes. Resultate: Die luminalen Oberflaechen von vier LVAD''s wurden mit autologen Ohrknorpelzellen besiedelt. Die Effiezienz der Zellbesiedelung betrug 95.11± 4.23% (n = 4). Der kumulative Zellverlust unter Flussbedingungen in vitro war geringer als 12% (n = 4). Nach sieben Tagen der in vivo Implantation zeigten die luminalen Oberflaechen des implantierten LVAD eine intakte, fest haftende Zellbesiedelung. Es wurden keine Thromboembolien waehrend der Nekropsie festgestellt. Schlussfolgerungen: Ohrknorpel stellt eine einfach und schnell erreichbare Quelle fuer autologe Ohrknorpelzellen dar, dessen Collagen Typ II und andere wichtige Bestandteile der extrazellulaeren Matrix sie dazu befaehigt, fest an den luminalen Oberflaechen der LVAD''s zu haften. Die hier beschriebene einfache Methode der Knorpelgewinnung und der Zellisolierung kann benutzt werden, um eine autologe Zellbeschichtung von LVAD''s und anderen implantierbaren kardiovaskulaeren Systemen vorzunehmen mit dem Ziel die Biokompatibilitaet dieser zu verbessern. Unsere erfolgreiche Feasibilitystudie in einem Kalbmodel fordert weitere in vivo Studien. / Background: Auricular elastic cartilage is a potential source of autologous cells for lining the luminal surfaces of left ventricular assist devices (LVAD''s) to improve long-term biocompatibility. We evaluated this potential in vitro and in vivo in a calf model. Methods: In vitro, auricular cartilage was harvested from the anesthetized ear of a calf, isolated, and cultured on tissue culture dishes. Primary chondrocytes were typed by immunocytochemistry, transferred into culture media, passaged twice, and seeded onto the blood-contacting luminal surfaces of four LVAD''s (HeartMate(R); Thermo Cardiosystems, Inc., Woburn, MA). The seeded cell linings were preconditioned under flow conditions in vitro to promote cell adhesion to the luminal surfaces. Seeding efficiency and cumulative cell loss under flow conditions in vitro were quantitated. In vivo, one of the four preconditioned, autologous chondrocyte-lined LVAD''s was implanted into the tissue-donor calf; run for 7 days; explanted; and finally evaluated grossly, by scanning electron microscopy, and by transmission electron microscopy. Results: Autologous chondrocytes were seeded onto the luminal surfaces of the four LVAD''s. The seeding efficiency was 95.11± 4.23% (n = 4). Cumulative cell loss during preconditioning under flow conditions in vitro did not exceed 12% (n = 4). After 7 days of in vivo implantation, the luminal surfaces of the implanted LVAD demonstrated an intact, strongly adherent cellular lining. There was no evidence of thromboembolic events at necropsy. Conclusions: Auricular elastic cartilage is a ready and easily accessible source of chondrocytes whose ability to produce collagen II and other important extracellular matrix constituents allows them to adhere strongly to the luminal surfaces of LVAD''s. The simple method of isolating and expanding auricular chondrocytes presented here could be used to provide autologous cell linings for LVAD''s and other cardiovascular devices to improve their long-term biocompatibility. Our successful short-term feasibility study in a calf model warrants further study in vivo.

Traditionally archaeology has referred to the anthropic sediments accumulated around prehistoric settlements with the blanket term ‘midden’. This is now recognised as an inadequate term to describe the complex formation processes and functions represented in these sediments. This thesis reviewed the body of evidence accumulated over the past century of research into Neolithic and Bronze Age settlements on the islands of the Scottish North Atlantic seaboard and extrapolated the many occurrences of ‘midden’. Several contexts emerged for these sediments including interior floors, hearths, exterior occupational surfaces, dumped deposits, building construction materials and abandonment infill. In addition, ‘midden’ is described added to cultivated soils to form fertile anthrosols. The way in which prehistoric communities exploited this material for agriculture and construction has been described through geoarchaeological research which implied that to past communities ‘midden’ was a valuable resource. This led to the formation of a model based upon a human ecodynamics framework to hypothesise sediment formation pathways. Rescue excavation at the Links of Noltland, Westray provided an opportunity to conduct a holistic landscape and fine resolution based study of Neolithic and Bronze Age settlement to test this model. The research incorporated auger survey, archaeological and geoarchaeological excavation, thin section micromorphology and SEM EDX analyses. Sediments identified in literature review and recovered from the field site were described using this toolkit and set within a cultural and environmental context. Results demonstrate that anthropic materials were incorporated into all contexts examined. Discrete burning and maintenance activities were found to have taken place during the gradual accumulation of open-air anthropic sediments whilst incorporation of fuel residues and hearth waste into floors lead to the gradual formation of ‘living floors’ inside structures. An unexpected discovery was evidence of animal penning within late Neolithic/Early Bronze Age settlement and the in situ burning of stabling waste. Three types iv | P a g e of land management strategy which relied upon the input of anthropic sediments were evidenced and the range and extent of anthropic inclusions in the landscape recorded. Spatial interpolation of auger survey data utilised a new sub-surface modelling technique being developed by the British Geological Survey to explore soil stratigraphic relationships in 3D. SEM EDX analysis supported micromorphological analysis providing chemical data for discrete inclusions and assisting in the identification of herbivore dun ash and the Orcadian funerary product ‘cramp’. SEM EDX analysis was also applied to fine organo-mineral material for statistical testing of nutrient loadings across context groups. It was found that anthropic sediments were enriched in macro and intermediate plant nutrients Mg, P, K, S and Ca compared to geological controls, and the application of anthropic material to cultivated soils improved soil fertility for the three observed land management practices. The versatility of anthropic sediments was explored through discussion of context groups based upon the results of this research and the potential significance of this material to prehistoric communities is explored.

La Constitution, entendue dans son acception la plus générale comme La marque suprême de souveraineté nationale, ne cesse d’évoluer au fil de l’approfondissement de la construction européenne. Un tel constat se manifeste à la fois dans le contenu matériel et normatif de la norme première, dans son aspect purement formel et dans son essence même. Pour s’en convaincre, il suffit de se reporter aux nombreuses révisions constitutionnelles ayant été effectuées sous la pression de l’intégration européenne. La doctrine évoque une communautarisation des Constitutions nationales voire une constitutionnalisation du droit communautaire. Dans cette optique, il convient de s’interroger, par le biais d’une démarche comparatiste évolutive, sur la portée effective et sur les conséquences de ces évolutions sur les contours et l’acception de la Constitution française.Est­-il encore possible d’évoquer un monopole de souveraineté pour caractériser cette dernière, face à l’exercice par l’Union européenne de la souveraineté transférée ? Est-­il réellement légitime, et juridiquement juste, de continuer à appréhender la Constitution à partir de son cadre national d’origine ? En d’autres termes, et d’une manière plus radicale, le concept de Constitution peut‐il encore être rattaché à un sens traditionnel et exclusif, tel qu’issu du droit interne? Face aux incertitudes européennes dont la norme suprême fait désormais l’objet, force est de dépasser le cadre d’étude fondamental traditionnel par la construction d’un nouveau concept de «Constitution», supplantant les principales définitions jusqu’ici admises. / The Constitution, taken in the most generally understood definition of supreme nationalauthority, is continuously evolving with the increasing structural complexity of the Europeancommunity . Such findings are in evidence not only in the material content and the normativestandard of the first degree but also in its purely formal aspect and its essence.To be persuaded this is happening, it is enough to look at the numerous constitutionalamendments brought about under the pressure of European integration.The tenet calls to mind a normalization of the national constitutions of member states into theframework of the European constitution .In this perspective, one has to ask through an evolutionary comparative step, whether thesechanges are being effective and the consequences they will have on the shaping andacceptance of the French Constitution.Is it still possible to think of the exclusive possessionof sovereignty when faced with the European Union transferred sovereignty rule.Is it truly legitimate and legally right to continue to perceive the constitution from its originalnational foundations. In other words and in a more radical way, can the concept ofConstitution be linked to a traditional and sole meaning as originating from a nationalprerogative.Faced with European uncertainties, whose legal supremacy has been put into question, onehas to go beyond the fundamentally traditional framework towards the building of a newconcept of "Constitution" which supersedes the main definitions as accepted to the presenttime.

Vergnaud (1985) propose une structure de type (S,I,S) qui sous-tend que la construction d’un concept scientifique est accompagnée entre autres de l’émergence d’un système d’invariant(s) lié au concept. Nous proposons ici d’observer si, en sciences physiques, sur l’exemple du concept d’élément chimique au sein de classes de seconde générale du lycée, l’élaboration de l’invariant, dans le cadre d’une telle structure (S,I,S), est, sinon la condition de celle du concept, susceptible de le rendre plus lisible. Nos résultats montrent que la construction du concept d’élément chimique semble être conditionnée par celle de son invariant. En revanche la réciprocité ne paraît pas aussi évidente. Nous observons des tendances similaires sur d’autres concepts en sciences physiques, lesquels sont en cours d’exploitation. Cela nous amène à penser que les invariants pourraient se voir doter, en sciences physiques, d’un statut didactique « majeur ». Nous proposons une ébauche de classification des invariants, en sciences physiques, afin de donner de la lisibilité aux objets complexes que sont les concepts scientifiques auxquels ils sont associés. Nous imaginons que toutes les disciplines pourraient « penser » leurs invariants et que ces derniers pourraient être valorisés, au sein des organismes de formation, pour ce qu’ils sont susceptibles d’apporter aux élèves dans un cursus d’apprentissage. / Vergnaud (1985) propose a structure of type (S, I, S) which underlies the construction of a scientific concept is accompanied by among others the emergence of a system invariant (s) related to the concept. We propose here to observe whether, physical sciences, the example of the concept of chemical element  within general classes of second  school, the development of the invariant under such a structure (S, I, S) is, if the condition of the concept, which may make it more readable. Our results show that the construction of the concept of chemical element seems to be conditioned by its invariant. However reciprocity does not seem so obvious.We observe similar trends on other concepts in the physical sciences, which are in operation. This leads us to believe that the invariants could be build, physical sciences, educational status "major". We propose a draft classification of invariants, physical sciences, in order to give clarity to complex objects that are scientific concepts which they are associated.We imagine that all disciplines could "think" their invariants and that they could be recovered within training organizations for what they are likely to provide students with a learning curve.

Made available in DSpace on 2016-04-28T20:39:28Z (GMT). No. of bitstreams: 1 Angela M M Harary.pdf: 622182 bytes, checksum: 1ed656f7ae92a8e7c4af98310faac04a (MD5) Previous issue date: 2007-06-01 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The purpose of this paper is to discuss what happens during a psychoanalytic experience, when something with a potential for change and growth is generated and what kind of linking favors it. Also, it runs through a fundamental psychic phenomenon of a specific symbiotic quality, capable of a high degree of regenerative and/or constitutive parts of the self. This paper is justified by the fact that more and more the psychoanalytic process has been seen as a result of the pair s interpenetration (transference/ countertransference) and for what is stimulated in the analyst as knowledge about his/her patient psychodynamics. Some clinical hypotheses have been put forward to explain the occurrences of phenomena that are analogous to a kind of immersion in affectionate dimensions of low awareness but necessary to achieve a deep affectionate interaction that would keep symbiotic fusion fantasies. Seven topics are highlighted in order to corroborate to the institution of a link that could support this symbiotic process and the intensity of the emotions present on it: comprehension, love, confidence, loss, truth, companionship and closeness X distance. Results of this research related to clinical aspects are the maternal holding function, as an integrating experience that follows and supports moments of turbulence, a kind of safety net under the trapeze offering security and also the phenomenon of a symbiosis as a fundamental constitutive part of the psychism. This development of the libido previous to the PS ↔ D oscillation could be part of the same dynamics and then, would be turned into a three-part circulation process: symbiotic, disintegrated, integrated / O objetivo do trabalho é discutir o que acontece na experiência do encontro analítico, na qual gera-se algo com potencial de mudança e crescimento e qual o tipo de ligação que o favorece. Discorre, também, sobre um fenômeno psíquico fundamental, de uma qualidade definida, simbiótica, capaz de um alto grau regenerador e/ou constitutivo do self. Justifica-se por ser o processo psicanalítico, cada vez mais, entendido como o produto da interpenetração do par (transferencial/ contratransferencial) e daquilo que é suscitado no analista como forma de conhecimento sobre a dinâmica do analisando. Levantaram-se hipóteses clínicas, sobre a ocorrência de fenômenos análogos a uma espécie de imersão de determinadas dimensões afetivas, pouco conscientes, porém necessárias a uma interação afetiva profunda que guardaria aspectos de fantasias fusionais simbióticas. Destacam-se sete tópicos que corroboram para a instauração de um vínculo que dê sustentação a esse processo e à intensidade das emoções presentes: compreensão, amor, confiança, perda, verdade, companhia e proximidade X distanciamento. Como resultados dessa pesquisa, evidenciou-se no caso clínico a função de holding materno como experiência integradora que acompanha e suporta momentos de turbulência, uma espécie de rede armada sob o trapézio a oferecer segurança e, também, o fenômeno de uma simbiose fundamental a fazer parte da construção do psiquismo. Esse desenvolvimento da libido anterior à oscilação PS ↔ D, poderia, então, fazer parte da mesma dinâmica que se transformaria em uma triangulação: simbiótico, desintegrado, integrado

Responsabilité civile et procédures collectives, sont des termes aux effets a priori inconciliables. Pourtant, la politique juridique de la procédure collective utilise, de manière à la fois cohérente et opportuniste, la responsabilité civile, qui est alors mise au service de ses finalités et de son régime et dont l’usage se révèle fluctuant et opportuniste. Le résultat ? La mutation de la responsabilité civile. En effet, d’une part l’efficacité juridique du droit des procédures collectives fait évoluer sa fonction. Fondée sur un équilibre des intérêts, elle laprotège. D’autre part, elle fait évoluer le régime de la responsabilité civile, que se soit ses conditions de fond ou de forme. Mais pourquoi circonscrire la protection de l’intérêt à la procédure collective ? Ne peut-on pas voir dans cette fonction la direction de l’évolution de la responsabilité civile en droit des affaires ? / Civil liability and collective procedures, are terms in the effects a priori irreconcilable. Nevertheless, the legal politics of the collective procedure uses, so as to coherent and opportunist time, the civil liability, which is then put in the service of its purposes and of his regime and the use of which shows itself fluctuating and opportunist. The profit ? The mutation of the civil liability. Indeed, on one hand the legal efficiency of the law of the collective procedures makes its function evolve. Established on a balance of the interests, itprotects her. On the other hand, it develops the regime of the civil liability, that is his conditions of bottom or shape. But why to confine the protection of the interest in the collective procedure? Cannot we see in this function, the direction of the evolution of the civil liability in business law?

<p>This dissertation considers packet-switched wireless networks for transmission of variable-rate layered hybrid video streams. Target applications are video streaming and broadcasting services. The work can be divided into two main parts.</p><p>In the first part, a novel quality-scalable scheme based on coefficient refinement and encoder quality constraints is developed as a possible extension to the video coding standard H.264. After a technical introduction to the coding tools of H.264 with the main focus on error resilience features, various quality scalability schemes in previous research are reviewed. Based on this discussion, an encoder decoder framework is designed for an arbitrary number of quality layers, hereby also enabling region-of-interest coding. After that, the performance of the new system is exhaustively tested, showing that the bit rate increase typically encountered with scalable hybrid coding schemes is, for certain coding parameters, only small to moderate. The double- and triple-layer constellations of the framework are shown to perform superior to other systems.</p><p>The second part considers layered code streams as generated by the scheme of the first part. Various error propagation issues in hybrid streams are discussed, which leads to the definition of a decoder quality constraint and a segmentation of the code stream to transmit. A packetization scheme based on successive source rate consumption is drafted, followed by the formulation of the channel code rate optimization problem for an optimum assignment of available codes to the channel packets. Proper MSE-based error metrics are derived, incorporating the properties of the source signal, a terminate-on-error decoding strategy, error concealment, inter-packet dependencies, and the channel conditions. The Viterbi algorithm is presented as a low-complexity solution to the optimization problem, showing a great adaptivity of the joint source channel coding scheme to the channel conditions. An almost constant image qualiity is achieved, also in mismatch situations, while the overall channel code rate decreases only as little as necessary as the channel quality deteriorates. It is further shown that the variance of code distributions is only small, and that the codes are assigned irregularly to all channel packets.</p><p>A double-layer constellation of the framework clearly outperforms other schemes with a substantial margin. </p><p>Keywords — Digital lossy video compression, visual communication, variable bit rate (VBR), SNR scalability, layered image processing, quality layer, hybrid code stream, predictive coding, progressive bit stream, joint source channel coding, fidelity constraint, channel error robustness, resilience, concealment, packet-switched, mobile and wireless ATM, noisy transmission, packet loss, binary symmetric channel, streaming, broadcasting, satellite and radio links, H.264, MPEG-4 AVC, Viterbi, trellis, unequal error protection</p>

This dissertation considers packet-switched wireless networks for transmission of variable-rate layered hybrid video streams. Target applications are video streaming and broadcasting services. The work can be divided into two main parts. In the first part, a novel quality-scalable scheme based on coefficient refinement and encoder quality constraints is developed as a possible extension to the video coding standard H.264. After a technical introduction to the coding tools of H.264 with the main focus on error resilience features, various quality scalability schemes in previous research are reviewed. Based on this discussion, an encoder decoder framework is designed for an arbitrary number of quality layers, hereby also enabling region-of-interest coding. After that, the performance of the new system is exhaustively tested, showing that the bit rate increase typically encountered with scalable hybrid coding schemes is, for certain coding parameters, only small to moderate. The double- and triple-layer constellations of the framework are shown to perform superior to other systems. The second part considers layered code streams as generated by the scheme of the first part. Various error propagation issues in hybrid streams are discussed, which leads to the definition of a decoder quality constraint and a segmentation of the code stream to transmit. A packetization scheme based on successive source rate consumption is drafted, followed by the formulation of the channel code rate optimization problem for an optimum assignment of available codes to the channel packets. Proper MSE-based error metrics are derived, incorporating the properties of the source signal, a terminate-on-error decoding strategy, error concealment, inter-packet dependencies, and the channel conditions. The Viterbi algorithm is presented as a low-complexity solution to the optimization problem, showing a great adaptivity of the joint source channel coding scheme to the channel conditions. An almost constant image qualiity is achieved, also in mismatch situations, while the overall channel code rate decreases only as little as necessary as the channel quality deteriorates. It is further shown that the variance of code distributions is only small, and that the codes are assigned irregularly to all channel packets. A double-layer constellation of the framework clearly outperforms other schemes with a substantial margin. Keywords — Digital lossy video compression, visual communication, variable bit rate (VBR), SNR scalability, layered image processing, quality layer, hybrid code stream, predictive coding, progressive bit stream, joint source channel coding, fidelity constraint, channel error robustness, resilience, concealment, packet-switched, mobile and wireless ATM, noisy transmission, packet loss, binary symmetric channel, streaming, broadcasting, satellite and radio links, H.264, MPEG-4 AVC, Viterbi, trellis, unequal error protection

根據瑞士有機農業研究所的全球有機市場報告指出，2013年全球有機農業產值為630億美金，相較於2011年增長25%，由此可見有機產業蓬勃發展。過往國內有關有機產業的研究，大多偏向探討有機農業的發展、消費者行為調查、通路行銷策略，對於有機商店創新層面著墨很少。另一方面，以往服務創新相關研究有提到組織方式與知識管理對其產生的影響，但探討的產業仍限縮在一般服務業，未曾針對有機商店作探討。基於上述的缺口，本研究以「有機認知」、「組織特性」、「知識取得」等三大構面為主軸，選擇國內三家有機零售通路商店進行深入研究，探討三大構面對服務創新的影響。 本研究得到的結論如下： (1) 有機零售通路業者共同採取的服務創新是複合式經營餐飲、不定期的講座與活動、網路平台、App互動與購物。 (2) 有機零售通路業者發展服務創新，其有機產品認知包含健康產品的定義、與農友間公平貿易。前者是說明店內產品的選擇，後者是說明其公平採購行為，兩者對於有機零售商店都是新服務概念。 (3) 有機零售通路會同時透過正式化的組織方式與非正式化的提案制度來激發創新。當公司不具備組織創業家精神，新服務發展將難以達成。 (4) 有機零售通路業者發展服務創新時，在外部連結與知識取得上，會以開放式創新的概念積極向外獲取所需之技術知識與市場知識，尤其注重一線員工與顧客的互動與顧客意見。 最後，本研究提出實務建議與後續研究之建議。 / According to the statistics of Research Institute of Organic Agriculture (FiBL), global output value was 15 billion dollars in 2013 and 25% growth from 2011, which shows that organic industry is a booming industry. Most of the past researches related to organic industry are focused on the “development of organic farming”, “consumer behavior”, “marketing strategy” and very few studies are conducted on the organic store innovation. On the other hand, most of the former studies of service innovation, knowledge management, and organizing focus on general service industry. The past studies of the cases are almost general service industry. Due to the research gap, this study establishes a research framework with four major constructs: organic product awareness, organizing, external sourcing of knowledge and service innovation. I select three organic retail stores and aim to find the relationship among them. Four major preliminary conclusions obtained from this study are as follows: (1) The observation of organic retail stores jointly take these actions, such as combinative restaurant, occasional lectures/activities, network platform and App interacting with shopping. (2) As far as organic retail stores for service innovation is concerned, firm’s organic product awareness consists of the definition of health products and fair trade between farmers. Both of them are the new service concepts. (3) As far as organic retail stores for service innovation is concerned, the firm may use both formal and informal organization. If firms do not acquire entrepreneurship orientation, new service development would not be accomplished. (4) As far as organic retail stores for service innovation is concerned, the firm will actively acquire both of technical knowledge and market knowledge. Especially stores pay attention to the views of frontline staff and customer feedback. Finally, this study draws some recommendations for both practitioners and follow-up researchers.

This thesis reports on experimental investigations of the mechanisms inherent in the joint action of short and continuous fibres in high-performance, cement-based composites. Experiments on different levels of observation (macro- meso- and micro-levels) were performed to provide detailed insights into the various effects of adding different types of short fibres (dispersed AR glass, integral AR glass and dispersed carbon fibres) on the strength, deformation, and failure behaviour of textile-reinforced concrete (TRC) subjected to tensile loading. Moreover, visual inspections of the specimens' surfaces and microscopic investigation of the fracture surfaces and the interface zone between fibre and matrix were performed and evaluated. Subsequently, the mathematical descriptions for TRC with short fibres under deformation controlled tensile loading conditions were derived based on a multi-scale rheological-statistical modelling approach. Based on a literature review, the state of the art is presented and discussed to identify key questions that are yet to be answered satisfactorily. This provides the starting point for the investigations presented in this thesis. The experimental program on the macro-level included uniaxial tension tests performed on thin, narrow plates reinforced by: a) only textile reinforcement, b) only short fibres, and c) hybrid reinforcement (both textile reinforcement with the addition of short fibres). Special attention was directed toward the course of the stress-strain relationship, crack pattern development, and fibre failure behaviour. The stress-strain curves resulting from uniaxial tension testing demonstrated clearly the positive influence of all types of short fibre on the mechanical performance of TRC. While the first-crack stress in TRC specimens increased significantly due to the addition of short fibres, an expansion of the strain region, where multiple cracks form, was observed for the stress-strain curves for TRC with added short fibres. The visual inspection of the specimens\' surfaces showed a higher number of cracks and finer crack patterns for given strain levels in the cases when short fibres were added to TRC. Moreover, depending on fibre type, the positive effects of the addition of short fibres on both tensile strength and work-to-fracture of the composite were found to vary significantly. The findings at the micro- and meso-levels of observation provided to a great extent a core of understanding of some particular mechanical behavioural properties of TRC with short fibres at the macro-level of observation. Thus, in addition to the experimental testing performed on composite materials with different parameter combinations, investigations of the action of individual material components, i.e., multifilament-yarns and single short fibres, embedded into cement-based matrices were carried out. It was found that short fibres indeed improve the bond between multifilament-yarns and the surrounding matrix. By their random positioning on the yarn\'s surface, short fibres built new adhesive cross-links which provided extra connecting points to the surrounding matrix. Furthermore, the water-to-binder ratio of the matrix influenced bond quality between fibre and matrix, i.e., various degrees of matrix-fibre bond were observed. As a result, the mechanical behaviour of the composite varied with w/b: While the good bond of the fibre embedded in a matrix with a low water-to-binder ratio leads to increase in stiffness and strength of the composite, fibres with weak bonding can be considered as defects with respect to stiffness as they lead to a decrease in the value. The thesis further derives the mathematical relationships for TRC with the addition of short fibres under deformation-controlled tensile loading. A physically based rheological model consisting of simple rheological elements was developed based on the experimental results on the micro-scale, using single-fibre pullout tests. Special attention was paid to the gradual de-bonding process and the resulting force-displacement branch. The model adequately reproduced both relevant fibre failure scenarios: fibre fracture and fibre pullout. By means of statistical procedures the combination of these models led to description of the stress-crack opening behaviour of an individual crack bridged by the given number of short fibres. The stress-strain relation for TRC with short fibres subjected to tensile loading was then derived. The concept followed at the macro-level of observation was modelling separately the three main regions of the characteristic stress-strain curve. The regions of crack-free material and crack-widening were considered linear and described based on the corresponding characteristic values of each region. The behaviour of the multiple cracking region was derived by considering an increasing number of cracks in serial interconnection and the contribution of the uncracked matrix in between. The stress transfer, i.e., bridging stress, across the crack was determined based on the contribution of both short fibres and multifilament-yarns. Behaviour of individual cracks was adjusted by varying the number of bridging fibres in different cracks and by varying the yarn bridging stress according to range observed in the pullout experiments. / In der vorliegenden Arbeit wird über Untersuchungen zu den Mechanismen der Wechselwirkungen zwischen Kurz- und Endlosfasern in zement-basierenten Hochleistungskompositen berichtet. Hierzu wurden experimentelle Untersuchungen auf verschiedenen Betrachtungsebenen (Makro-, Meso- und Mikroebene) durchgeführt mit dem Ziel, detaillierte Erkenntnisse zu den Auswirkungen der Zugabe von verschiedenen Arten von Kurzfasern (disperse und integrale AR-Glasfasern, Kohlenstofffasern) hinsichtlich des Festigkeits-, Verformungs- und Bruchverhaltens von Textilbeton (engl.: textile-reinforced concrete = TRC) unter Zugbeanspruchung zu gewinnen. Die Bruchflächen sowie die Gestalt der Interphase zwischen der Bewehrung aus Textilien oder Kurzfasern und der umhüllenden zemengebundenen Matrix wurden mit optischen und elektronenmikroskopischen Verfahren hinsichtlich der Wechselwirkungsphänomene ausgewertet. Die Ergebnisse der experimentellen Arbeiten bildeten den Ausgangspunkt für die mathematischen Beschreibungen für TRC mit Kurzfasern unter verformungsgesteuerter Zugbelastung. Die Formulierungen erfolgten auf Grundlage multiskalarer rheologisch-statistischer Modellansätze. In einer Literatursichtung wurde zunächst der Kenntnisstand zu den Materialien und zum Verhalten von TRC und Faserbeton unter Zugbeanspruchung dargestellt und diskutiert. Die noch zu erforschenden Fragen wurden präzisiert und die Grundlagen für deren Untersuchung geschaffen. Bei den Experimenten auf der Makroebene wurden drei Bewehrungsvarianten betrachtet: a) textile Bewehrung, b) Kurzfaserbewehrung, und c) hybride Bewehrung (Textil und Kurzfasern). An Dehnkörpern wurde die Spannungs-Dehnungsbeziehung unter einachsiger Zugbelastung studiert und dabei das Rissbild und die Phänomene des Faserversagens detailliert beobachtet. Anhand der Spannungs-Dehnungsbeziehungen konnte gezeigt werden, dass die Zugabe von Kurzfasern bei allen untersuchten Kurzfaserarten zu einer erheblichen Verbesserung der Leistungsfähigkeit von Textilbeton führt. Dies zeigte sich unter anderem in einer ausgeprägten Anhebung der Erstrissspannung sowie der Entwicklung von zahlreicheren und damit feineren Rissen, die zu einer Verbesserung der Duktilität führten. Ebenso wurden Steigerungen der Zugfestigkeit und der Energiedissipation festgestellt. In welchem Maß diese Änderungen stattfinden, hängt von der Art der Kurzfasern ab. Die Experimente auf der Mikro- und Mesoebene wurden so konzipiert, dass sie die Erkundung der Mechanismen, die den auf der Makroebene beobachteten Phänomenen zugrunde liegen, unterstützten. Auf der Mesoebene wurden Mulitifilamentgarnauszugversuche (mit und ohne Kurzfasern in der Matrix) und auf der Mikroebene Einzelfaserauszugsversuche für alle betrachteten Kurzfasertypen durchgeführt. Es wurde festgestellt, dass die Kurzfasern den Verbund zwischen Matrix und Multifilamentgarn verbessern. Kurzfasern können bei zufälliger Positionierung an der Garnoberfläche zusätzliche Haftbrücken bzw. Verbindungsstellen zu umgebender Matrix bilden. Für die Verbundqualität zwischen Faser und Matrix ist der Wasser-Bindemittel-Wert (W/B-Wert) von entscheidender Bedeutung. Bei einer Matrix mit niedrigem W/B-Wert führt die gute Qualität des Verbunds der eingebetteten Fasern zu einer Erhöhung der Steifigkeit sowie der Festigkeit des Komposites. Bei hohem W/B-Wert haben die Fasern einen schlechten Verbund zur Matrix und müssen überwiegend als Fehl- bzw. Schwachstellen betrachtet werden. Festigkeit und Steifigkeit des Komposits nehmen daher ab. Die Ableitung mathematischer Beziehungen für Textilbeton mit Zugabe von Kurzfasern unter verformungsgesteuerter Zugbelastung erfolgte aufbauend auf den Ergebnissen der experimentellen Untersuchungen auf der Mikroebene. Die Einzelfaserauszugsversuche wurden mit Hilfe eines physikalisch basierten Modelles nachgebildet, das aus einfachen rheologischen Elementen besteht. Phänomene wie die graduelle Ablösung der Faser, Faserbruch und Faserauszug wurden durch eine entsprechende Kombination und Parametrierung der rheologischen Elemente abgebildet. Im Ergebnis wurden zutreffende Kraft-Rissöffnungsbeziehungen modelliert. Auf der Mesoebene wurde ein einzelner Riss modelliert, der sowohl durch Multifilamentgarne als auch Kurzfasern überbrückt werden kann. Der rissüberbrückenden Wirkung der zahlreichen Kurzfasern wurde mit Hilfe statistischer Methoden rechnung getragen, die unterschiedliche Faser-Risswinkel und Einbindelängen berücksichtigen. Die resultierende Spannungs-Rissöffnungskurve umfasst die rissüberbrückende Wirkung von Multifilamentgarnen und Kurzfasern. Auf der Makroebene kann die charakteristische Spannungs-Dehnungsbeziehung von TRC unter Zugbelastung in 3 Bereiche (Zustände I, IIa, IIb) unterteilt werden. Die Kurvenverläufe im Zustand I (ungerissenen) sowie Zustand IIb (abgeschlossenes Rissbild) wurden als linear betrachtet und basierend auf den entsprechenden charakteristischen Werten des jeweiligen Zustands beschrieben. Das Verhalten im Zustand IIa (multiple Rissbildung) wurde durch die Reihenschaltung einer zunehmenden Anzahl von Rissen sowie den Beitrags der ungerissenen Matrix zwischen den Rissen modelliert.