Présentation de deux expériences, utilisant les corrélations de polarisations entre des paires de photons optiques issus d'une cascade atomique (dont l'une est très proche de l'expérience utilisée par Bell), en utilisant des polariseurs a une voie ou des polarimètres optiques. Discussion de la précision statistique des expériences, en bon accord avec les prédictions quantiques, ce qui semblerait exclure la probabilité de réinterprétation de la mécanique quantique par une théorie locale a paramètres supplémentaires.

L'objectif central de cette thèse est d'exploiter les propriétés quantiques du champ électromagnétique pour développer de nouveaux dispositifs de communication. L'étude porte sur les composantes de quadrature (variables quantiques continues) d'un mode impulsionnel du champ lumineux. Une démonstration expérimentale de cryptographie quantique avec des états cohérents a été réalisée. Le dispositif se base sur des impulsions modulées en amplitude et en phase et comportant en moyenne une centaine de photons. Pour chaque impulsion lumineuse, une détection homodyne résolue en temps permet de mesurer une composante de quadrature particulière avec une forte efficacité. Une clé secrète a ainsi été transmise à un débit de 1.7 Mbits/s en l'absence de pertes et 75 kbits/s pour une transmission présentant des pertes de 3.1 dB, ce qui ouvre la voie pour des applications de cryptographie quantique à hauts débits. Afin d'étudier l'utilisation de spécificités quantiques, nous avons développé une source impulsionnelle d'états comprimés et d'états intriqués. Cette source utilise des conversions non-linéaires d'impulsions ultrabrèves intervenant dans un cristal mince de niobate de potassium. Suivant la configuration, la réduction du bruit en quadrature est de 2.7 dB sous le niveau de bruit quantique standard, ou les corrélations entre les quadratures des faisceaux intriqués sont de 2.5 dB. Grâce à ce dispositif, nous avons mis en oeuvre la première expérience de "dégaussification", pour transformer des impulsions de vide comprimé en des états non-gaussiens. Ce protocole est directement lié à la distillation de l'intrication de variables continues, qui permet d'améliorer la portée des dispositifs de cryptographie. Enfin, des schémas sont étudiés pour réaliser des tests complets des inégalités de Bell avec des variables continues mesurées par des détections homodynes.

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The study unpacked the meaning and the value of intonjane in traditional Xhosa communities. It also provides a critical analysis and interpretation of the intonjane custom and in particular its impact on the upbringing of a Xhosa traditional girl child. It investigates the value of this practice, especially in relation to where it is still being performed, even in our modern times. I researched closely into all aspects of how the girls were brought up, and with what social values. The data collection has been conducted through interviews with the Philakukuzenzela group when they were in Grahamstown Art Festival in July 2011 who come from a place called Centuli, and other people (abaThembu) who practice and have knowledge of the different aspects of the intonjane process and observation during the actual ceremonies in O. R. Thambo district, and in Gemvale near Port St Johns in the Province of the Eastern Cape. Interviews were conducted in Xhosa and translated into English. This Visual Narrative investigates and contributes to the debate regarding the value of traditional African thought and how it can enrich our contemporary belief system. The objective was to investigate the essence and merit of the knowledge imparted by elderly women to young girls during the initiation period of intonjane within Xhosa traditional communities. This study provides a foundation and springboard for my practical artworks which utilized symbols and metaphors to express my understanding of the important events and stages associated with this traditional ceremony. Clay medium was used as the medium of expression, applying different techniques such as throwing, press mold, slab building, coiling, engraving, sewing and inlaying, with press mold being the main technique utilized. My artworks are of three different types, which are symbolic of the three aspects or stages, of liminality, namely: pre-liminal, liminal and post-liminal. / Art history, Visual arts and Musicology / M.A. (Visual Arts)

There were used human skeletal remains from eight Older and Late Eneolithic burial sites from Bohemia to set their health status. I used remains of 307 individuals. Paleodemography analysis of cemeteries and cultures was made. There were shown possible modifications of life table values based on experiment with modern population values. During paleoepidemiological analysis I described the most important categories of pathological findings. The results of analysis were used to make comparisons between themselves and with individuals from the Moravian cemetery of Bell Beaker Culture from Hoštice I za Hanou. An unexpected result was the statistically significant difference in the height of Bohemian and Moravian population of Bell Beaker Culture. Male individuals of Funnel Beaker Culture had the lowest height of all. There were found only two congenital anomalies, plagiocephalia and Klippel-Feil syndrome (fused cervical vertebrae). X-ray images were made of the most important findings for better diagnosis. Except the classic categories of pathologies I detected two cases of hyperostosis frontalis interna, both females from a burial site of Corded Ware Culture in Vikletice. In five cases were found osteoplastic growth on the visceral surface of the ribs of individuals of Bell Beaker Culture from...

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-03-05T18:27:51Z No. of bitstreams: 2 Fernando_Martins2017.pdf: 3146180 bytes, checksum: a1dcde101c1559cda9b93c488d0f17e9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-05T18:27:51Z (GMT). No. of bitstreams: 2 Fernando_Martins2017.pdf: 3146180 bytes, checksum: a1dcde101c1559cda9b93c488d0f17e9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / For species that do not exhibit parental care such as oviparous insects, choosing a favorable oviposition site is of utmost importance for brood success. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate humidity. However, at least one lab experiment with mole crickets (Orthoptera: Gryllotalpoidea) indicated a linear oviposition responses to substrate humidity. The house cricket Acheta domesticus (Orthoptera: Grylloidea) also shows a linear juvenile body growth response to substrate humidity, which suggests a positive relationship between humidity and oviposition preference. We evaluated the relationship between oviposition frequency and substrate humidity in forest litter- dwelling species, primarily composed of Ubiquepuella telytokous, using field experiments. We also tested oviposition responses of U. telytokous to substrate humidity in a laboratory experiment. We offered oviposition substrates that varied in humidity from zero percent to maximum substrate water absorption capacity. Oviposition preference was estimated using presence or absence of eggs as a binary response variable, adjusted logistic regression (GAMM) was used to test for non-linear responses, and GLMs were used to test linear responses. We found that oviposition probability increased linearly with substrate humidity for U. telytokous in both field and lab experiments. Our results demonstrate the importance of substrate humidity as an ecological niche requirement for this species. This work bolsters knowledge of litter cricket life history association with humidity, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying. / Para espécies que não apresentam cuidados parentais, tais como insetos ovíparos, a escolha de um local de oviposição favorável é de extrema importância para o sucesso da prole. A teoria do nicho prevê que a oviposição de grilos deve mostrar uma resposta em forma de sino à umidade do substrato. Entretanto, pelo menos um experimento de laboratório com paquinhas (Orthoptera: Gryllotalpoidea) indicou uma resposta de oviposição linear em relação a umidade do substrato. O grilo doméstico Acheta domesticus (Orthoptera: Grylloidea) também apresenta um crescimento corporal dos juvenis linear em relação a umidade do substrato, o que sugere uma relação positiva entre umidade e preferência de oviposição. Aqui testamos a relação entre a frequência de oviposição e a umidade do substrato, em espécies de grilos de serrapilheira florestal, primariamente compostas Ubiquepuella telytokous, utilizando experimentos de campo. Também testamos as respostas de oviposição de U. telytokous em experimentos de laboratório. Oferecemos substratos de oviposção que variaram a umidade de zero porcento até a capacidade máxima de absorção do substrato. A preferência de oviposição foi estimada utilizando presença ou ausência de ovos como uma variável resposta binária, regressão logística ajustada (GAMM) para testar respostas não lineares, e GLMs para testar respostas lineares. Verificamos que a probabilidade de oviposição aumenta linearmente com a umidade do substrato para U. telytokous, nos experimentos de campo e laboratório. Nossos resultados demonstram a importância da umidade do substrato como requisito de nicho ecológico para Ubiquepuella telytokous. Este trabalho reforça o conhecimento da associação de história de vida de grilos com a umidade, e sugere que esses organismos podem ser particularmente ameaçados por mudanças climáticas que tornam habitats áridos.

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Diploma thesis deals with the design and stress analysis of the rocker suspension for an autocross car. The research describes some real cases of using suspension with pushrod and rocker in motorsport. Subsequently, the work deals with the design of the wheel bump/rebound limiting stops and bump/rebound measuring. The challenge is to design a component shape, size and select fit of a rocker with an emphasis on low weight whilst maintaining sufficient strength and rigidity. The design study include stress analysis which leads to optimize the final shape.

Folgender Artikel stellt die nach der politischen Wende in Sachsen gefundenen und bisher nur aus Vorberichten bekannten Glockenbechergräber vor. Die archäologisch-kulturelle Zuordnung der Gräber steht im Vordergrund, da einige Gräber keine oder kulturunspezifische Beigaben enthielten. Durch die Analyse eines internen und externen Grabkontextes kann der Großteil der Gräber der archäologischen Kultur mit Glockenbecher zugeordnet und die mit den Gräbern in Beziehung stehenden Befunde interpretiert werden. Weiterhin wird die Beziehungen zwischen den archäologischen Kulturen Glockenbecher und Aunjetitz thematisiert und auf besondere Aspekte der Glockenbecherbestattungssitte in Nordwestsachsen eingegangen. / This article presents the Bell Beaker graves found in Northwest Saxony after 1989. Because some of the burials contained none or only culturally non-specific grave goods, the overall analysis focused on the cultural classification of the graves. Investigation of the internal and external grave context allowed to classify the majority as graves of the Bell Beaker Culture and subsequently to interpret the features related to the graves. Furthermore the relationship between the Bell Beaker and Únetice Culture is discussed and special regional aspects of Bell Beaker burial customs are described in detail.

The deterministic generation and manipulation of quantum states has attracted much interest ever since the rise of quantum mechanics. Large-scale, distributed quantum states are the basis for novel applications such as quantum communication, quantum remote sensing, distributed quantum computing or quantum voting protocols. The necessary infrastructure will be provided by distributed quantum networks, allowing for quantum bit processing and storage at single nodes. Quantum states of light then allow for inter-node transmission of quantum information. Transmission losses in optical fibers may be overcome by quantum repeaters, the quantum equivalent of classical signal amplifiers. The fragility of quantum superposition states makes building such networks very challenging. Hybrid solutions combine the strengths of different physical systems: Efficient quantum memories can be realized using alkali atoms such as rubidium. Leading in the deterministic generation of single photons and polarization entangled photon pairs are semiconductor InAs/GaAs quantum dots grown by the Stranski-Krastanov method. Despite remarkable progress in the last twenty years, complex quantum optical protocols could not be realized due to low degree of entanglement, low brightness and broad wavelength distribution. In this work, an emerging family of epitaxially grown GaAs/AlGaAs quantum dots obtained by droplet etching and nanohole infilling is studied. Under pulsed resonant two-photon excitation, they emit single pairs of entangled photons with high purity and unprecedented degree of entanglement. Entanglement fidelities up to f = 0.94 are observed, which are only limited by the optical setup or a residual exciton fine structure. The samples exhibit a very narrow wavelength distribution at rubidium memory transitions. Strain tuning is applied via piezoelectric actuators to allow for reversible fine-tuning of the emission frequency. In a next step, active feedback is employed to stabilize the frequency of single photons emitted by two separate quantum dots to an atomic rubidium standard. The transmission of a rubidium-based Faraday filter serves as the error signal for frequency stabilization. A residual frequency deviation of < 30MHz is achieved, which is less than 1.5% of the quantum dot linewidth. Long-term stability is demonstrated by Hong-Ou-Mandel interference between photons from the two quantum dots. Their internal dephasing limits the expected visibility to V = 40%. For frequency-stabilized dots, V = (41 ± 5)% is observed as opposed to V = (31 ± 7)% for free-running emission. This technique reaches the maximally expected visibility for the given system and therefore facilitates quantum networks with indistinguishable photons from distributed sources. Based on the presented techniques and improved emission quality, pivotal quantum communication protocols can now be implemented with quantum dots, such as transferring entanglement between photon pairs. Embedding quantum dots in a dielectric antenna ensures a bright emission. For the first time, entanglement swapping between two pairs of photons emitted by a single quantum dot is realized. A joint Bell measurement heralds the successful generation of the Bell state Ψ+ with a fidelity of up to (0.81 ± 0.04). The state's nonlocal nature is confirmed by violating the CHSH-Bell inequality with S = (2.28 ± 0.13). The photon source is tuned into resonance with rubidium transitions, facilitating implementation of hybrid quantum repeaters. This work thus represents a major step forward for the application of semiconductor based entangled photon sources in real-world scenarios.