Dissertations / Theses on the topic 'Photon framework'

Intravital microscopy such as in vivo imaging of brain dynamics is often performed with custom-built microscope setups controlled by custom-written software to meet specific requirements. Continuous technological advancement in the field has created a need for new control software that is flexible enough to support the biological researcher with innovative imaging techniques and provide the developer with a solid platform for quickly and easily implementing new extensions. Here, we introduce HelioScan, a software package written in LabVIEW, as a platform serving this dual role. HelioScan is designed as a collection of components that can be flexibly assembled into microscope control software tailored to the particular hardware and functionality requirements. Moreover, HelioScan provides a software framework, within which new functionality can be implemented in a quick and structured manner. A specific HelioScan application assembles at run-time from individual software components, based on user-definable configuration files. Due to its component-based architecture, HelioScan can exploit synergies of multiple developers working in parallel on different components in a community effort. We exemplify the capabilities and versatility of HelioScan by demonstrating several in vivo brain imaging modes, including camera-based intrinsic optical signal imaging for functional mapping of cortical areas, standard two-photon laser-scanning microscopy using galvanometric mirrors, and high-speed in vivo two-photon calcium imaging using either acousto-optic deflectors or a resonant scanner. We recommend HelioScan as a convenient software framework for the in vivo imaging community.

Paid Open Access

Wellenleiter Quantenelektrodynamik (Wellenleiter QED) ist ein wichtiger Baustein in vielen zukünftigen, auf Quantenmechanik basierenden Technologien wie z.B. Quantencomputer. Ein typisches Modellsystem besteht aus einem Zwei-Niveau-System (two level system, TLS), das an einen eindimensionalen Wellenleiter gekoppelt wurde. Der Wellenleiter ist dabei durch eine Dispersionsrelation charakterisiert und kann unter anderem Bandkanten enthalten. Wir haben in der Dissertation einen neuartigen Zugang zur Wellenleiter QED präsentiert. Dieser Zugang basiert auf der Quantenfeldtheorie und ermöglicht die Berechnung Greenscher Funktionen im ein- und zwei-Anregungs Unterraum. Diese Greenschen Funktionen wurden benutzt um die Streumatrix und die spektrale Dichte in beiden Unterräumen zu berechnen. Desweiteren konnten wir mit Hilfe von Feynman-Diagrammen die physikalischen Prozesse in der Störungsreihe der Greenschen Funktionen identifizieren. Dies war besonders im zwei-Anregungs-Unterraum von Nutzen. In diesem Fall verhält sich das System nichtlinear, da das TLS nur eine Anregung absorbieren kann. Dadurch werden Effekte induziert wie photon bunching und die effiziente Anregung eines gebundenen Atom-Photon Zustandes. Es war uns möglich diese Effekte in der Störungsreihe der Greenschen Funktion wieder zu finden. Desweiteren haben wir die Greenschen Funktionen im Orts-Zeit-Raum benutzt um ein- und zwei-Photon-Wellenpakete zu propagieren. Es hat sich herausgestellt dass das Verhältnis von Pulsbreite zur spontanten Emissions-zeit sowohl das Streuverhalten als auch die maximale Anregung des TLS bestimmt. Letztendlich haben wir den Einfluss von Unordnung im Wellenleiter auf das Zerfallsverhalten des TLS untersucht. Wir haben entdeckt dass der gebundene Atom-Photon Zustand instabil wird sobald die Unordnung einen kritischen Wert erreicht. Darüberhinaus haben wir eine spezielle Klasse Feynman Diagramme identifiziert, die dem Zerfall eine nichtmarkovsche Dynamik verleihen.
Waveguide quantum electrodynamics (waveguide QED) can be considered as a building block for many prospective technologies like quantum computing. A prototypical system consists of a two-level system (TLS) coupled to a one-dimensional waveguide. The waveguide is characterized by its dispersion relation and can also feature a band edge/slow-light regime. In this thesis we have presented a new theoretical framework for waveguide QED, based on quantum field theory. The framework provides the Green''s functions of the system in the single- and two-excitation sectors for an arbitrary dispersion relation. We have calculated the scattering matrix and the spectral density in both sectors. Furthermore, we have also represented the Green''s functions in the form of Feynman diagrams, from which we can identify the underlying physical processes. A special property of the system is that it behaves nonlinear in the case of two or more photons. This is rooted in the structure of the TLS, which can at most absorb one excitation. The nonlinearity leads to two effects: photon bunching and the efficient excitation of an atom-photon bound state. We have found both effects within our framework and we were able to assign them individual terms in the perturbation series of the Green''s function. Furthermore, we have used the Green''s function in space-time domain to propagate Gaussian one- and two-photon wavepackets. Here, we have identified the ratio of the pulsewidth and the spontaneous emission time as the parameter which governs both the scattering behavior of the photons and the maximal TLS excitation. Eventually, we have investigated the effects of disorder in the waveguide on the decay properties of the TLS. We have found here that the atom-photon bound state is stable for small disorder, but breaks down at sufficiently strong disorder. Furthermore, we have identified a special class of diagrams which render the system non-Markovian even for energies far away from the band edge.

Main goals of this work are to present game development process and game engine Unity3D and develop game server with application programming interface including framework for using the server. The first part of this work is tageted on history of game genres and game development process. The second part of the thesis is dedicated to describing Unity3D game engine with focus on Unity3D networking. Development tools used in implementation and server desing included framework for use of the server are described in the third part of the thesis. In the last chapter of this work are described most important classes used in developed application.

The synthesis, characterization and photophysical properties of three Zr-based Metalorganic frameworks (MOFs) assembled from 2,6-anthracenedicarboxylic acid (2,6-ADCA, 2,6- MOF) and 1,4-anthracenedicarboxylic (1,4-ADCA, 1,4-MOF), and 9,10-anthracenedicarboxylic acid (9,10-ADCA, 9,10-MOF) are described. The crystal structure of the 9,10-MOF was elucidated by synchrotron powder X-ray diffraction (PXRD) analysis and is isostructural with the well-known UiO-66 framework. The 2,6-MOFs also form highly crystalline, octahedral-shaped structures and was characterized by PXRD. Le Bail refinement of the powder pattern revealed that the 2,6-MOF also has UiO-type crystal structure. Conversely, incorporation of the 1,4-ADCA ligand results in large rod-shaped crystals. The excited-state properties of the MOFs were examined using steadstate diffuse reflectance, steady-state emission spectroscopy and time-correlated single photon counting (TCSPC) spectroscopy and are compared to those of the corresponding ligand in solution. Both the unique fluorescent properties of the ligand as well as individual framework structure, result in distinctive luminescent behavior and dictate the extent of intermolecular interactions. Specifically, the 2,6-MOF displays monomeric emission with a fluorescence lifetime (t) of 16.6 ± 1.1 and fluorescence quantum yield (Ff). On the other hand, the 1,4-MOF displays both monomeric and excimeric emission, with corresponding lifetime values of 7.5 ± 0.01 and 19.9 ± 0.1, respectively and a quantum yield of 0.002 ± 0.0001. The propensity for photon upconversion through sensitized triplet-triplet annihilation (TTA-UC) was probed in the three anthracene-based MOFs. The MOFs were surface-modified with Pd(II) mesoporphyrin IX (PdMP) as the triplet sensitizer. Upconverted emission from the 9,10-MOF was observed, with a quantum efficiency (FUC) of 0.46 % and a threshold intensity (Ith) of 142 mW/cm2 . The variation of the spacing between the anthracene units in the MOFs was found to have significant impact on TTA-UC. As a result, upconverted emission is only displayed by the 9-10-MOF. The distance between anthracene linkers in the 2,6-MOF are too large for TTA to occur, while the short distances in the 1,4-MOF inhibit upconversion through competitive excimer formation. To further explore the effects of chromophore spacing on energy transfer processes, a series of zinc-based mixed-ligand MOF were constructed from Zn(II) tetrakis(4- carboxyphenyl)porphyrin (ZnTCPP) and pyrazine, 2,2′-bipyridine (pyz) or 4,4′-bipyridyl (bpy) or 1,4-di(4-pyridyl)benzense (dpbz), comprising ZnTCPP/Zn paddlewheel layers. Across this series, the porphyrin spacing was approximately 6 Å, 11 Å and 16 Å for pyz, bpy and dpbz, respectively. The photophysical properties of the MOFs were explored using stead-state diffuse reflectance spectroscopy and steady-state and time-resolved emission spectroscopies. Florescence quenching studies examined the correlation between porphyrin spacing and efficiency of energy transfer.
Ph. D.

The development of therapeutic drugs or drug systems that enhance a cancer patient's quality of life during treatment is a primary goal for many researchers across a wide range of disciplines. Many investigators turn to nanoparticles (~50-200 nm in size) that tend to accumulate in tumor tissues in order to deliver active drug compounds to specific sites in the body. This targeted delivery approach would reduce the total body effects of current cancer drugs that result in unwanted (sometimes painful and even fatal) side effects. One of the main obstacles however, is ensuring that drugs incorporated into the nanoparticles are anchored such that premature drug release is prohibited. Also, while it is important to ensure strong drug-nanocarrier interactions, the nanocarrier must be able to release the drug when it has reached its biological target. We have developed a nanocarrier that provides a platform for drug systems that could achieve this drug release via the use of a light "trigger". Metal-Organic Frameworks (MOFs) are a relatively new class of often highly porous materials that act as "sponges" for the absorption of various small molecules. MOFs are so named because they consist of metal clusters that are linked by organic compounds to form networked solids that are easily tuned based on the choice of metal and organic "linker". We have developed a MOF nanocarrier incorporating benign zirconium (IV) metal clusters bridged by an organic component that changes shape when illuminated with a light source. The resulting material is therefore not stable upon irradiation due to the organic linker shape change that disturbs the MOF structure and causes it to degrade. When loaded with drugs, this photo-enhanced degradation results in the release of the cargo thereby, providing a handle on controlling drug release with the use of a light trigger. We have demonstrated that in the presence of the MOF nanocarrier incorporating 5-fluorouracil (a clinically available cancer drug), very low toxicity to human breast cancer cells is observed in the dark, however, cell death occurs in the presence of a light source. These reports offer a model MOF nanocarrier system that could be used to incorporate various drugs and therefore tune the system to an individual patient's needs. Furthermore, we also developed a material that is capable of providing magnetic resonance imaging (MRI) contrast by changing the metal to manganese (II). MRI contrast agents are compounds that serve to either darken or brighten an MRI image based on the agent used and therefore they aid in clinical diagnosis by making internal abnormalities easier to spot. Currently gadolinium (III) complexes are the most widely used contrast agents; however, the toxicity of gadolinium (III) has been shown to be responsible for the development of nephrogenic systemic fibrosis in some patients. This manganese material has also shown useful for the attachment of fluorescent dyes that can aid in the benchtop optical diagnosis of biopsies. These reports provide a basis for developing ways to offer controlled drug delivery in cancer patients and to aid in cancer diagnosis using MOF materials, in an effort to reach the goals of comfortable cancer treatment.
Ph. D.

Les phonons mous et le couplage électron-phonon sont considérés comme responsables d’un grand nombre de transition de phase. Pour en comprendre complétement les mécanismes, il est nécessaire d’étudier à la fois les modifications structurales, les changements de configuration électronique et les dynamiques de réseau cristallin. De toute évidence, cela représente une charge de travail expérimental et théorique considérable, voire même hors d’atteinte.Néanmoins, il est parfois possible d’introduire certaines simplifications et d’ainsi rendre une telle étude réalisable. C’est le cas pour les deux systèmes au cœur de ce travail de thèse, pour lesquels la transition de phase peut être diviser en deux instabilités : l’une est structurale, intrinsèque aux éléments constitutifs du système et l’autre, superposée, provient de la configuration électronique. L’interaction entre ces instabilités est illustrée à travers l’exemple de deux systèmes à priori hétérogènes, la famille des bronzes monophosphate de tungstène d’une part et l’antimoine d’autre part, qui révèleront finalement posséder des similarités inattendues. La combinaison des techniques de diffusion diffuse et de diffusion inélastique de rayons X permet des observations qualitatives et une meilleure compréhension de la situation pour les deux systèmes.Les bronzes monophosphate de tungstène font partie de la famille des oxydes quasi-2D, (PO2)4(WO3)2m, qui ont la particularité d’être sujet à des instabilités de type onde de densité de charges (ODC). Ces bronzes sont constitués d’une structure de perovskite vide composée par des couches octaédriques (WO3)2m. L’épaisseur de chacune de ces couches est définie par la valeur de m, qui mène ainsi à différents types de phase d’ODC. Le cas du terme m=2 a aussi été étudié car le fait que les chaînes zig-zag y soient isolées conduit à une instabilité quasi-1D. La présence d’une phase d’ODC a été découverte à TC=270K avec q=0.25b*. Cette phase est engendrée par le mouvement à corps rigide, plus exactement, par les basculements corrélés des octaèdres. Pour les autres termes (m=6,7 et 8), l’instabilité structurale a une origine différente et est liée à l’agencement en couches de WO3, plus particulièrement aux déplacements corrélés des chaînes W-O-W-O. Ces derniers sont la cause d’une forte diffusion diffuse sur des plans spécifiques, résultant de la présence de phonons ’relativement’ mous localisés dans la même région. Ensuite, l’emboitement de la surface de Fermi quasi-2D est à l’origine de l’ancrage du vecteur de modulation sur une valeur spécifique de transfert de moment, définit par l’interaction de deux instabilités, structurale et électronique. De façon remarquable, l’amplitude des déplacements des atomes de tungstène dans le terme m=8 est beaucoup plus élevée que dans le m=6.L’antimoine à température ambiante possède une structure rhomboédrique, dérivant d’une légère distorsion de la structure cubique primitive (CP) par transition de Peierls. Sous pression, la distorsion se réduit sans toutefois disparaître complétement, puisque l’antimoine se transforme dans un premier temps en une série de structures complexes, pour finalement adopter celle possédant la plus grande symétrie, la structure cubique centrée (CC). De la même façon que pour les bronzes, les caractéristiques de la diffusion diffuse ainsi que, dans une certaine mesure, les particularités de la dynamique du réseau rhomboédrique, s’expliquent à travers de l’instabilité du réseau cubique primitif. Cette dernière est liée aux déplacements corrélés dans les chaînes avec direction pseudo-cubique <100>. En outre, les détails de la transition de phase peuvent être explicités par l’association de l’analyse des vecteurs critiques de la transformation CC-CP avec les résultats expérimentaux obtenus sur la dépendance en pression de l’énergie des phonons
A large number of phase transitions can be interpreted as being driven by phonon softening and/or electron-phonon coupling. Thus, a full mechanistic description requires the understanding of structural transformation, changes in electronic structure and lattice dynamics. All together this represents an enormous, for many cases unrealisable, experimental and theoretical effort.However, with the introduction of appropriate assumptions the problem may be simplified. Here we concentrate on two systems, where the interpretation of the phase transition may be split into an intrinsic instability of the building blocks combined with a superimposed electronic instability. We illustrate the interplay between the framework and electron-phonon-related instabilities using the seemingly heterogeneous examples of phosphate tungsten bronzes and elementary antimony. Based on the combined results from diffuse and inelastic X-ray scattering, we propose for the two systems a picture that explains the experimental observations. The similarities found between these two systems are deemed to be rather surprising.Monophosphate tungsten bronzes are a family of quasi-2D-oxides, (PO2)4(WO3)2m, that exhibits charge density wave (CDW) instability. They contain empty perovskite WO3 slabs with varying thickness between different members, characterised by the $m$ value. This thickness defines the sequence of charge density wave phases that appear on cooling. The degenerate case of $m$=2, presenting a quasi-1D instability, was explored since the WO3-octahedra zig-zag chain is isolated. A CDW phase (TC=270K and q=0.25b*) is found to be linked to a rigid-body motion, precisely, to a correlation in the tilting of the octahedra. For the others studied members, as m=6,7 and 8, we found another kind of structural instability. In this case the origin comes from the WO$_3$ slabs framework, realised as correlated displacements of tungsten atoms along the octahedral 4-fold axis direction (W-O-W-O direction). This leads to a strong x-ray diffuse scattering localised in specific planes, linked to relatively soft phonons modes. Specific Fermi surface nesting, close to the 2D case, gives rise to a freezing of the modulations at the specific momentum transfer, defined by the interplay of two instabilities, the structural and electronic one. Remarkably, the displacements of W for m=8 are much superior than in m=6.Elemental antimony at ambient condition has an A7 rhombohedral structure, obtained by small distortion from primitive cubic (PC) lattice through a Peierls transition. Under pressure, the distortion is reduced, but remains finite, as antimony transforms through a series of highly complex structures, before adopting as last the highest-symmetry body-centred cubic (BCC) phase. The main diffuse scattering features and to some extent the peculiarities in the lattice dynamics of the A7 phase – as above - can be explained by the instability of the primitive cubic network with respect to correlated displacements along the chains with <100> pseudo-cubic directions. Analysis of critical vectors for the BCC-PC transformation together with experimentally obtained phonon-energies pressure dependence provides further insights into the details of the phase transformation

The aim of this work is to create an application on Windows Mobile 6 platform for photo publication on the internet. Photos will be associated with geographic information. User will be able to attach geographic information to the photograph with use of connected GPS device and subsequently send these photographs to online publication system directly from mobile device.

This research explores the synthesis of anthracene and stilbene-based metal-organic framework (MOF) structures as potential scintillating (radioluminescent) materials for use in the detection of gamma radiation. The organic molecules 9,10-anthracenedicarboxylic acid (ADCH2) and trans-4,4’-stilbenedicarboxylic acid (SDCH2), were each used as a linker, in combination with a range of lanthanide metal ions, to synthesize novel three dimensional MOF structures under hydrothermal conditions. With ADCH2, the early period lanthanides yield isostructures with the metal ion in higher coordination (nine) than for those with late period metals (seven). The ADC-MOFs show linker-based photoluminescence properties with well defined vibronic peaks in their emission profile and their emission (λmax~435 nm) blue shifting from that of the ADCH2 powder (~500 nm) and closer to the organic molecule in monomer arrangement (λmax ~ 420 nm). The structures also show photoluminescence lifetimes between 1 and 2 ns, which is similar to the reported value for monomeric anthracene units. The blue-shift and reduction in lifetime, compared to ADCH2, are indicative of minimal π-π interactions amongst the aromatic moieties, thereby limiting the non-radiative relaxation pathways. On exposure to ionizing radiation (protons and g- rays), the ADC-MOFs demonstrated scintillation properties, with a radioluminescence lifetime of ~ 6 ns which is similar to that of the ADCH2 powder. A combination of SDCH2 and lanthanide metal ions produced two isostructured MOFs containing Tm3+ and Er3+, under the hydrothermal synthesis conditions explored. The 3-D structure contained ultra large diamond-shaped pores with dimensions of 16 Å x 30 Å. A blue-shift of fluorescence spectra was observed for the SDC-MOF structures (λmax ~ 425 nm) compared to that of bulk SDCH2 powder (λmax ~475 nm), and closely resembling that of monomeric isolated SDC units (λmax~475 nm). Their photoluminescence lifetime is ~0.76 ns, about half of that observed for SDCH2 powder. The blue shift and reduction in lifetime (compared to SDCH2) is attributed to minimal π-π interactions between SDC units in the MOF structure, thus minimizing associated non-radiative relaxation pathways. The isolation of anthracene and stilbene in MOF structures therefore has the potential to improve their performance as scintillators.

The main objectives of this project are the synthesis and redox- or photo-active modification and CO2 adsorption studies of metal-organic frameworks (MOFs) based on Cu3-pyrazolate secondary building units (SBUs). Trinuclear copper(II) complexes of the formula [Cu3(µ3-O)(µ-4-R-pz)3X3]z have been studied extensively due to their redox, magnetic and catalytic properties. In earlier work, we have shown that trinuclear copper(II) complexes of the formula [Cu3(µ3-O)(µ-4-R-pz)3X3]z pz = pyrazolato anion; R = H, CH(O), Cl, Br and NO2; X = Cl, NCS, CH3COO, CF3COO and pyridine – can be oxidized to the corresponding z+1, formally CuII2CuIII, species. In this project, fourteen (14) new copper-pyrazolate complexes of varying nuclearities (Cu3, Cu6, Cu7 and Cu12), terminal ligands (-NO2, py, -N3, -Cl) and bridging ligands (4-Cl-pzH and 4-Ph-pzH) have been synthesized. Efforts have been made to prepare MOFs based on the Cu3(µ3-O)-SBUs. While attempting to design the most suitable SBU for redox-active MOF construction, it was found that the one-electron oxidation of the all-CuII complex [Cu3(µ3-O)(µ-pz)3(NO2)3]2–, [8]2-, was achieved at redox potential more cathodic than any other Cu3(µ3-O)-complexes studied in our laboratory. The mixed-valent compound, [Cu3(µ3-O)(µ-pz)3(NO2)3]–, [8]-, the easiest accessible CuII2CuIII species known to date, was characterized spectroscopically. Compound [8] and analogous [11] release NO almost quantitatively upon the addition of PhSH or acetic acid. The system is catalytic in the presence of excess nitrite. Before embarking on the study of photo-active MOFs, a simpler model compound – a dimer of trimer [{Cu3(µ3-OH)(µ-4-Cl-pz)3(py)2}2(µ-abp)](ClO4)4 [21], where abp = 4,4’-azopyridine, was synthesized and its photochemistry was studied. The absorption spectra recorded before and after irradiation indicated a structural change. Two dimensional (2D) and three dimensional (3D) materials with {[Cu3(µ3-OH)(µ-4-R-pz)3]2+}n SBUs where R = Ph or Cl , which can potentially undergo cis/trans-isomerization, have been prepared during this project. A Phenyl substituent at 4-position on the pyrazole ligand leads to the formation of new class of 2D sheets. Three new 3D porous MOFs based on {[Cu3(µ3-OH)(µ-4-Cl-pz)3]2+}n SBUs have interpenetrated- lattice structures and are capable of adsorbing CO2 selectively. Compounds FIU-1 and FIU-3 also exhibit hysteretic sorption-desorption profiles indicating the flexibility of the MOFs upon adsorption. Compound FIU-1 demonstrates the usefulness of a hexanuclear CuII -pyrazolate moiety as an SBU for generating 3-fold interpenetrated 3D polymeric network. Complexes FIU-2 and FIU-3 have novel 3-fold interpenetrating 3D hexagonal framework structures. Compound FIU-2 crystallizes in the monoclinic crystal system with the P21/c space group, whereas FIU-3 crystallizes in triclinic space group P . Both structures contain Cu3-SBUs connected by the linkers through the Cu-termini.

Les MOFs sont des solides à la structure cristalline poreuse à base de clusters métalliques et de ligands organiques qui font l'objet de très nombreuses études, dans des champs d'applications très variés, qui vont de la catalyse au « drug delivery », en passant par le stockage de gaz et, plus récemment, en tant que senseurs biologiques. Les ligands organiques, qui les constituent, peuvent lorsqu'ils possèdent un point d'ancrage, comme des groupements amino, être fonctionnalisés grâce à des réactions chimiques. Les travaux présentés dans cette thèse reportent la fonctionnalisation de MOFs, via différentes stratégies, comme des greffages covalent et issues de la chimie de coordination, tel que le couplage peptidique ou encore la synthèse d'urée. Dans cette thèse, est notamment présentée une nouvelle méthode permettant de greffer très rapidement des peptides chiraux dans les nanopores des MOFs. Une large bibliothèque MOF-peptides a ainsi été obtenue et caractérisée. Ces nouveaux composés ont également été utilisés pour l'ancrage de complexes organométalliques dans les cavités des MOFs. Suivant un échange de ligands post-synthétique, il a aussi été possible d'intégrer un complexe organométallique photo-catalytique dans la structure d'un MOF, améliorant ainsi ses activités et sélectivités pour la photo-réduction de CO2. Enfin, les performances catalytiques de ces derniers matériaux MOFs se sont révélées supérieures aux versions homogènes des complexes, ce qui offre de nouvelles opportunités pour la catalyse fine
Metal Organic Frameworks, MOFs, are porous crystalline solid based on metal clusters and organic ligands, investigated for numerous applications such as catalysis, drug delivery, gas storage and, more recently, biosensors. The work presented in this thesis focuses on functionalizing MOFs through different strategies, such as covalent grafting or surface coordination chemistry, through chemical reactions, such as peptide coupling or synthesis of urea. In particular, a new method to very quickly graft chiral peptides into the nanopores of MOFs is reported. A large library of MOF-peptides has thus been obtained and characterized. These novel compounds have also been used for grafting organometallics in the cavities of MOFs. Following a post-synthetic ligand exchange, it was also possible to integrate a photocatalytic complex in the structure of a MOF, improving its activities and selectivities for the photocatalytic CO2 reduction. In general, the catalytic performances of these materials were superior to those of their homogeneous counterparts, thus further expanding the potential of MOFs as well-defined heterogeneous catalysts for fine chemistry

Les travaux présentés dans ce manuscrit s’inscrivent dans le cadre général de la conversion et du stockage de l’énergie lumineuse. Dans ce domaine, l’utilisation de MOFs (Metal-Organic Frameworks) polyfonctionnels n’en est qu’à ses débuts et ils sont principalement utilisés sous forme de poudre cristalline. Or le développement de ces MOFs sur un support solide est essentiel dans l’obtention d’un objet technologiquement avancé répondant à des critères industriels. Les travaux réalisés lors de ce projet ont donc porté sur la croissance contrôlée de matériaux hybrides polyfonctionnels de type MOF sur une surface conductrice transparente TCO (Transparent Conductive Oxide). Les différentes fonctionnalités ont été introduites au sein du MOF par intégration d’une partie photosensible et d’une unité catalytique.A partir de systèmes de MOFs modèles à base de zirconium, il a été possible de produire des systèmes polyfonctionnels par modifications directement pendant la synthèse et/ou post synthèse. Le contrôle de la croissance, en maîtrisant les conditions expérimentales lors de la synthèse solvothermale directe in situ, nous a permis d’obtenir une couche de cristaux monodisperses solidement attachés aux supports TCO. Des efforts importants ont également été dédiés à la compréhension des mécanismes de croissance des MOF sur support TCO. Des essais de photodégradation du bleu de méthylène (polluant organique) ont permis de valider le potentiel photochimique de nos dispositifs.La méthodologie développée pour le contrôle de la croissance des MOFs à base de zirconium a été transposée avec succès à des analogues à base de titane, démontrant la portabilité de la stratégie vers d’autres types de MOFs. Ces derniers ont été utilisés en photo-réduction du CO2 lors d’essais préliminaires (collaboration avec le Collège de France) conduisant sélectivement à l’obtention de formiate
This work is focused on the development of a functionalization method of TCO transparent conductive surfaces (Transparent Conductive Oxide) by hybrid multifunctional materials, Metal-Organic Frameworks (MOFs). Different properties are provided within the MOF by adding different photosensitive and catalytic units. The development of such materials is in its infancy and they have been mainly developed as crystalline powder. However the development of these MOFs onto a solid support is challenging but also essential toward obtaining a technologically advanced device.This project is focused on the growth controlled of MOFs crystals onto TCO support. From a Zirconium material, it was possible to obtain multifunctional systems by changing components directly during the synthesis or by post synthesis modifications. It has been possible to control the growth of materials on the support by direct in situ solvothermal synthesis and to obtain a monodisperse layer of crystals well anchored to the TCO supports. Photodegradation of methylene blue (organic pollutant) has been performed to validate their photoreactivity.The methodology developed with the Zirconium based MOF has been implemented successfully in a similar compound to include higher photosensitizer components and with titanium-based MOFs. It shows the portability of the strategy towards other types of MOFs. They were used in CO2 photo-reduction (in collaboration of the College de France) where selectively of formate production was observed

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2015-05-13T18:09:31Z No. of bitstreams: 1 Carina Mersoni.pdf: 19788868 bytes, checksum: 0a73e013af257abfd6d16b1a83c37afd (MD5)
Made available in DSpace on 2015-05-13T18:09:31Z (GMT). No. of bitstreams: 1 Carina Mersoni.pdf: 19788868 bytes, checksum: 0a73e013af257abfd6d16b1a83c37afd (MD5) Previous issue date: 2014-04-01
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Esta pesquisa tem por objetivo investigar como são construídos os retratos de fontes populares no Diário Gaúcho, jornal popular lançado em 2000 pelo Grupo RBS no Rio Grande do Sul. A partir de pesquisa bibliográfica e exploratória, realizamos etnografia, acompanhando o trabalho de editores, fotógrafos e repórteres pelo período de cinco dias, em atividades internas e externas. No relato de observações e conversas com os profissionais da redação, junto às fotografias que registram o trabalho da equipe, são analisados retratos que tiveram acompanhamento na produção e edição. A partir destas informações, elaboramos categorias nas quais dispomos nossas apropriações e tensionamentos: o ambiente, o sujeito, a pauta, a história, os problemas sociais, e o espaço gráfico e a busca pela visibilidade. Os apontamentos permitiram identificar o enquadramento jornalístico no retrato, pensando desta forma o quadro fotográfico como espaço de produção de sentidos. Identificamos que as fontes populares estão frequentemente relacionadas a pautas que tratam de problemas sociais e as imagens evidenciam os dramas vividos, forma que o jornal encontra para sensibilizar a sociedade e buscar soluções. O jornal mantém um relacionamento muito próximo com suas fontes e preocupa-se em construir uma imagem positiva desses sujeitos, valorizando, desta forma, os gestos espontâneos. Mostrar o ambiente onde estão essas fontes também é uma meta constante, apesar de os espaços do projeto gráfico destinados à fotografia, muitas vezes, serem reduzidos. Nas matérias de serviços, esses sujeitos ainda são transformados em instrumentos de instrução aos leitores, servido de exemplo para as questões explicativas, especialmente nas imagens, já que o jornalismo popular aposta nos recursos visuais para se comunicar com seu público.
This research aims to investigate how portraits of popular sources on the Diario Gaucho are made, a popular newspaper launched in 2000 by RBS Group in Rio Grande do Sul. From bibliographic and exploratory research we conducted ethnography, watching the work of editors, photographers and reporters for five days in indoor and outdoor activities. In the account ofobservations and conversations with professionals in the newsroom, along with photographs that record the team's work, pictures that were followed in the productionand editing are analyzed. From this information, we developed categories in which we have our appropriations and tensions allocated: the environment, the subject, the agenda, history, social problems, graphic space and the quest for visibility. The notes allowed the identification of the journalistic framing in the picture, thinking this way the photographic picture as a space for production of senses. We found that the popular sources are often related to agendas that deal withsocial problems and the images show the lived dramas, a way that the paper finds to touch society and seek solutions. The newspaper maintains a very close relationship with its sources and worries about building a positive image of those subjects, enhancing thus the spontaneous gestures. Showing the environment where these sources are located is also a constant target, although the spaces of graphic design destinated for photography are often reduced. In articles of service, those subjects are still transformed into instruments of instrction to readers, serving as an example to explaining matters, especially in the images, sincethe popular journalism believes in visual resources to communicate with its audience.

[ES] En los últimos años, distintos proyectos alrededor del mundo se han centrado en el diseño de supercomputadores capaces de alcanzar la meta de la computación a exascala, con el objetivo de soportar la ejecución de aplicaciones de gran importancia para la sociedad en diversos campos como el de la salud, la inteligencia artificial, etc. Teniendo en cuenta la creciente tendencia de la potencia computacional en cada generación de supercomputadores, este objetivo se prevee accesible en los próximos años. Alcanzar esta meta requiere abordar diversos retos en el diseño y desarrollo del sistema. Uno de los principales es conseguir unas comunicaciones rápidas y eficientes entre el inmenso número de nodos de computo y los sitemas de memoria. La tecnología fotónica proporciona ciertas ventajas frente a las redes eléctricas, como un mayor ancho de banda en los enlaces, un mayor paralelismo a nivel de comunicaciones gracias al DWDM o una mejor gestión del cableado gracias a su reducido tamaño. En la tesis se ha desarrollado un estudio de viabilidad y desarrollo de redes de interconexión haciendo uso de la tecnología fotónica para los futuros sistemas a exaescala dentro del proyecto europeo ExaNeSt. En primer lugar, se ha realizado un análisis y caracterización de aplicaciones exaescala. Este análisis se ha utilizado para conocer el comportamiento y requisitos de red que presentan las aplicaciones, y con ello guiarnos en el diseño de la red del sistema. El análisis considera tres parámetros: la distribución de mensajes en base a su tamaño y su tipo, el consumo de ancho de banda requerido a lo largo de la ejecución y la matriz de comunicación espacial entre los nodos. El estudio revela la necesidad de una red eficiente y rápida, debido a que la mayoría de las comunaciones se realizan en burst y con mensajes de un tamaño medio inferior a 50KB. A continuación, la tesis se centra en identificar los principales elementos que diferencian las redes fotónicas de las eléctricas. Identificamos una secuencia de pasos en el diseño de un simulador, ya sea haciéndolo desde cero con tecnología fotónica o adaptando un simulador de redes eléctricas existente para modelar la fotónica. Después se han realizado dos estudios de rendimiento y comparativas entre las actuales redes eléctricas y distintas configuraciones de redes fotónicas utilizando topologías clásicas. En el primer estudio, realizado tanto con tráfico sintético como con trazas de ExaNeSt en un toro, fat tree y dragonfly, se observa como la tecnología fotónica supone una clara mejora respecto a la eléctrica. Además, el estudio muestra que el parámetro que más afecta al rendimiento es el ancho de banda del canal fotónico. El segundo estudio muestra el comportamiento y rendimiento de aplicaciones reales en simulaciones a gran escala en una topología jellyfish. En este estudio se confirman las conclusiones obtenidas en el anterior, revelando además que la tecnología fotónica permite reducir la complejidad de algunas topologías, y por ende, el coste de la red. En los estudios realizados se ha observado una baja utilización de la red debido a que las topologías utilizadas para redes eléctricas no aprovechan las características que proporciona la tecnología fotónica. Por ello, se ha propuesto Segment Switching, una estrategia de conmutación orientada a reducir la longitud de las rutas mediante el uso de buffers intermedios. Los resultados experimentales muestran que cada topología tiene sus propios requerimientos. En el caso del toro, el mayor rendimiento se obtiene con un mayor número de buffers en la red. En el fat tree el parámetro más importante es el tamaño del buffer, obteniendo unas prestaciones similares una configuración con buffers en todos los switches que la que los ubica solo en el nivel superior. En resumen, esta tesis estudia el uso de la tecnología fotónica para las redes de sistemas a exascala y propone aprovechar
[CA] Els darrers anys, múltiples projectes de recerca a tot el món s'han centrat en el disseny de superordinadors capaços d'assolir la barrera de computació exascala, amb l'objectiu de donar suport a l'execució d'aplicacions importants per a la nostra societat, com ara salut, intel·ligència artificial, meteorologia, etc. Segons la tendència creixent en la potència de càlcul en cada generació de superordinadors, es preveu assolir aquest objectiu en els propers anys. No obstant això, assolir aquest objectiu requereix abordar diferents reptes importants en el disseny i desenvolupament del sistema. Un dels principals és aconseguir comunicacions ràpides i eficients entre l'enorme nombre de nodes computacionals i els sistemes de memòria. La tecnologia fotònica proporciona diversos avantatges respecte a les xarxes elèctriques actuals, com ara un major ample de banda als enllaços, un major paral·lelisme de la xarxa gràcies a DWDM o una millor gestió del cable a causa de la seva mida molt més xicoteta. En la tesi, s'ha desenvolupat un estudi de viabilitat i desenvolupament de xarxes d'interconnexió mitjançant tecnologia fotònica per a futurs sistemes exascala dins del projecte europeu ExaNeSt. En primer lloc, s'ha dut a terme un estudi de caracterització d'aplicacions exascala dels requisits de xarxa. Els resultats de l'anàlisi ajuden a entendre els requisits de xarxa de les aplicacions exascale i, per tant, ens guien en el disseny de la xarxa del sistema. Aquesta anàlisi considera tres paràmetres principals: la distribució dels missatges en funció de la seva mida i tipus, el consum d'ample de banda requerit durant tota l'execució i els patrons de comunicació espacial entre els nodes. L'estudi revela la necessitat d'una xarxa d'interconnexió ràpida i eficient, ja que la majoria de comunicacions consisteixen en ràfegues de transmissions, cadascuna amb una mida mitjana de missatge de 50 KB. A continuació, la tesi se centra a identificar els principals elements que diferencien les xarxes fotòniques de les elèctriques. Identifiquem una seqüència de passos en el disseny i implementació d'un simulador: tractar la tecnologia fotònica des de zero o per ampliar un simulador de xarxa elèctrica existent per modelar la fotònica. Després, es presenten dos estudis principals de comparació de rendiment entre xarxes elèctriques i diferents configuracions de xarxes fotòniques mitjançant topologies clàssiques. En el primer estudi, realitzat tant amb trànsit sintètic com amb traces d'ExaNeSt en un toro, fat tree i dragonfly, vam trobar que la tecnologia fotònica representa una millora notable respecte a la tecnologia elèctrica. A més, l'estudi mostra que el paràmetre que més afecta el rendiment és l'amplada de banda del canal fotònic. Aquest darrer estudi analitza el rendiment d'aplicacions reals en simulacions a gran escala en una topologia jellyfish. Els resultats d'aquest estudi corroboren les conclusions obtingudes en l'anterior, revelant també que la tecnologia fotònica permet reduir la complexitat d'algunes topologies i, per tant, el cost de la xarxa. En els estudis anteriors ens adonem que la xarxa estava infrautilitzada principalment perquè les topologies estudiades per a xarxes elèctriques no aprofiten les característiques proporcionades per la tecnologia fotònica. Per aquest motiu, proposem Segment Switching, una estratègia de commutació destinada a reduir la longitud de les rutes mitjançant la implementació de memòries intermèdies en nodes intermedis al llarg de la ruta. Els resultats experimentals mostren que cadascuna de les topologies estudiades presenta diferents requisits de memòria intermèdia. Per al toro, com més gran siga el nombre de memòries intermèdies a la xarxa, major serà el rendiment. Per al fat tree, el paràmetre clau és la mida de la memòria intermèdia, aconseguint un rendiment similar tant amb una configuració amb memòria intermèdia en tots els co
[EN] In the last recent years, multiple research projects around the world have focused on the design of supercomputers able to reach the exascale computing barrier, with the aim of supporting the execution of important applications for our society, such as health, artificial intelligence, meteorology, etc. According to the growing trend in the computational power in each supercomputer generation, this objective is expected to be reached in the coming years. However, achieving this goal requires addressing distinct major challenges in the design and development of the system. One of the main ones is to achieve fast and efficient communications between the huge number of computational nodes and the memory systems. Photonics technology provides several advantages over current electrical networks, such as higher bandwidth in the links, greater network parallelism thanks to DWDM, or better cable management due to its much smaller size. In this thesis, a feasibility study and development of interconnection networks have been developed using photonics technology for future exascale systems within the European project ExaNeSt. First, a characterization study of exascale applications from the network requirements has been carried out. The results of the analysis help understand the network requirements of exascale applications, and thereby guide us in the design of the system network. This analysis considers three main parameters: the distribution of the messages based on their size and type, the required bandwidth consumption throughout the execution, and the spatial communication patterns between the nodes. The study reveals the need for a fast and efficient interconnection network, since most communications consist of bursts of transmissions, each with an average message size of 50 KB. Next, this dissertation concentrates on identifying the main elements that differentiate photonic networks from electrical ones. We identify a sequence of steps in the design and implementation of a simulator either i) dealing with photonic technology from scratch or ii) to extend an existing electrical network simulator in order to model photonics. After that, two main performance comparison studies between electrical networks and different configurations of photonic networks are presented using classical topologies. In the former study, carried out with both synthetic traffic and traces of ExaNeSt in a torus, fat tree and dragonfly, we found that photonic technology represents a noticeable improvement over electrical technology. Furthermore, the study shows that the parameter that most affects the performance is the bandwidth of the photonic channel. The latter study analyzes performance of real applications in large-scale simulations in a jellyfish topology. The results of this study corroborates the conclusions obtained in the previous, also revealing that photonic technology allows reducing the complexity of some topologies, and therefore, the cost of the network. In the previous studies we realize that the network was underutilized mainly because the studied topologies for electrical networks do not take advantage of the features provided by photonic technology. For this reason, we propose Segment Switching, a switching strategy aimed at reducing the length of the routes by implementing buffers at intermediate nodes along the path. Experimental results show that each of the studied topologies presents different buffering requirements. For the torus, the higher the number of buffers in the network, the higher the performance. For the fat tree, the key parameter is the buffer size, achieving similar performance a configuration with buffers on all switches that locating buffers only at the top level. In summary, this thesis studies the use of photonic technology for networks of exascale systems, and proposes to take advantage of the characteristics of this technology in current electrical network topologies.
This thesis has been conceived from the work carried out by Polytechnic University of Valencia in the ExaNeSt European project
Duro Gómez, J. (2021). Photonic Interconnection Networks for Exascale Computers [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/166796
TESIS

Les réserves de combustibles fossiles diminuent et leur utilisation illimitée depuis la révolution industrielle a généré de profonds changements du climat, notamment des cycles de la température atmosphérique. Stocker l'énergie solaire sous forme d'hydrogène produit par dissociation de l'eau est un moyen idéal pour combattre le réchauffement climatique. Les matériaux de la famille des «metal organic framework» (MOF) commencent à être utilisés comme photo-électrocatalyseurs, notamment pour la photo-dissociation de l'eau. Leur porosité extrêmement élevée et leur grande polyvalence, tant chimique que structurelle, les désignent comme des candidats potentiels pour faciliter l'absorption du rayonnement solaire et catalyser la dissociation de l'eau dans les cellules photoélectrochimiques. En contrôlant la composition chimique et le dopage du linker utilisé dans le MOF, il est possible d'ajuster l'énergie de la bande interdite, de favoriser la fonctionnalisation sur des substrats très variés ou encore d'ajuster leur résistance à la corrosion dans divers environnements chimiques. Ce sont donc des matériaux d'un grand intérêt pour la catalyse, l'électrocatalyse ou la photo-électro-catalyse. D'autre part, le TiO₂ nano-structuré, par exemple sous forme de tapis d’épaisseur micrométrique de nanotubes ou de nanofils, parfois appelé TNA, est un matériau bien adapté à la construction de photoanodes pour le dégagement d'oxygène en milieu aqueux. Il a déjà été largement étudié et décrit dans la littérature. Au cours de notre thèse, nous avons fabriqué des matériaux composites constitués de MOF de métaux de transition (Ni, Co, Fe) déposés sur TNA (TDNR et TNTA). Pour cela, nous avons utilisé une méthode électrochimique d'électrodéposition. Cela nous a permis de déposer des nanoparticules métalliques sur du TNA à potentiel fixe - 1,0 V puis de les transformer par réaction chimique avec des ligands organiques (BTC, BDC, et 2MZ) par voie thermo-thermique. Les matériaux obtenus présentent une activité électrocatalytique significative et une excellente durabilité photoélectrochimique. Ces matériaux composites ont été utilisés avec succès comme phase active dans des photo-électrodes pour la réaction de dégagement d'oxygène moléculaire (OER)
The fossil fuel reserves are dwindling and their unrestricted use has generated profound changes in Earth's surface temperature and climate. Storing solar energy in the form of hydrogen produced by dissociation of water is an ideal way to mitigate global warming. Materials from the “metal organic framework” (MOF) family are starting to be used as photo-electrocatalysts, especially for photo-dissociation of water. Their extremely high porosity and their great versatility, both chemical and structural, designate them as potential candidates to facilitate the absorption of solar radiation and catalyze the dissociation of water in photoelectrochemical cells. By controlling the chemical composition and doping of the linker used in the MOF, it is possible to adjust the band gap energy, to favor the functionalization on very varied substrates or even to adjust their resistance to corrosion in various chemical environments. They are therefore materials of great interest for catalysis, electrocatalysis or photo-electro-catalysis. On the other hand, nano-structured TiO₂, for example in the form of nanotube or nanowire mats, sometimes called TiO₂ nanoarray (TNA), is a material very suitable for the construction of photoanodes for the evolution of oxygen in aqueous medium. It has already been extensively studied and described in the literature. During our thesis, we manufactured composite materials made up of MOFs of transition metals (Ni, Co, Fe) deposited on TNA (network of nanotubes or nanowires). For this we used an electrochemical method of electrodeposition (cyclic voltammetry). This allowed us to deposit metallic nanoparticles on TNA with fixed potential - 1.0 V and then transform them by chemical reaction with organic ligands (1,3,5-benzenetricarboxylic acid, BTC, 1,4-benzenedicarboxylic acid, BDC and imidazole, 2MZ) by thermal-thermal route. The materials obtained exhibit significant electrocatalytic activity and excellent photoelectrochemical durability. These composite materials have been successfully used as an active phase in photo-electrodes for the oxygen release reaction (OER)

La structuration multi-échelle (à l’échelle micro- et nanométrique) de matériaux fonctionnels est un thème de recherche particulièrement actif en raison du grand potentiel des dispositifs miniatures utilisables en microélectronique, en optique (contrôle solaire, photonique) en microfluidique (lab-on-a-chip) ou pour de la détection de molécules cibles. Plusieurs techniques de micronanofabrication sont utilisées pour réaliser ces dispositifs miniaturisés. D’une part, des techniques dites « Top-Down » qui sont utilisées pour créer des formes complexes à l’échelle micro- et nanométriques à partir de matériaux massifs. Cette approche repose sur des techniques de lithographie qui offrent une grande liberté sur l’architecture finale du dispositif. Cependant, ce large choix de formes et de structures se fait au prix d’un faible rendement de fabrication qui diminue considérablement le transfert vers la production à grande échelle. A l’inverse, la fabrication de matériaux multi-échelle peut être faite par l’assemblage d’éléments moléculaires (« building blocks »). Cette seconde approche, dite « Bottom-Up » a le mérite de pouvoir être employée sur de grande surfaces mais permet seulement d’obtenir des architectures simples. La combinaison de ces deux approches ouvre un large champ d’exploration et permettrait d’obtenir des structures complexes inédites inaccessibles autrement. Le but de cette thèse est de combiner les approches « Top-Down » et « Bottom-Up » pour obtenir des matériaux à architecture hiérarchique et qui possèdent à la fois des propriétés chimiques et optiques originales. Concrètement, le cœur de ce travail de doctorat a été le dépôt par voie liquide (« Chemical Liquid Deposition ») de couches minces nanoporeuses grâce à une technique de trempage-retrait (« Dip-Coating »). Ce dépôt est suivi d’une structuration induite par évaporation ou bien par lithographie. La nanoporosité de ces couches minces, qui peuvent êtres inorganique ou organique-inorganique (hybride), est induite par un phénomène d’auto-assemblage se déroulant pendant la phase de séchage du film. La structure multi-échelle résultante possède une organisation périodique à l’échelle micro- voire submicrométrique (structure photonique) mais également une nanoporosité (<100 nm) structurée; le dispositif photonique est utilisé pour détecter des vapeurs de Composés Organiques Volatiles (COV). Un accent sera mis sur la compatibilité de ces capteurs optiques avec les caméras de smartphone. Le but final est en effet de fabriquer des capteurs à bas coût, dont la réponse optique est directement lisible par un smartphone
Multi-scale structuration of functional materials at nano- and micro- levels is an active scientific field driven by the tremendous potential of miniaturized devices in microelectronics, optics (light harvesting, photonics), sensing (selective sensors) or microfluidics (lab-on-a-chip). Diverse micro-nanofabrication techniques are exploited for device fabrication. On one hand, Top-Down techniques are developed to fabricate complex micro- and nano- structures from bulk materials; this approach relies on lithography which offers a wide flexibility on the final object architecture but suffers from low-throughput that hinders its use for large-scale production. On the other hand, Bottom-Up techniques based on the assembly of molecular building blocks are suited for the large-scale fabrication of nanostructured materials but are limited to simple architectures. The fruitful combination of both approaches is thus a vast field of investigation with promising technological outcomes.The scope of this thesis is to combine Bottom-Up and Top-Down approaches to obtain hierarchical architectures with original chemical characteristics and optical properties. In practical terms, the deposition by Chemical Liquid Deposition (dip-coating) of nanoporous inorganic or organic-inorganic (hybrid) films structured by self-assembly and the subsequent patterning by either lithographic or evaporation-driven patterning will be presented. The resulting multi-scale structures possess periodic micro- or submicro- organization and engineered nanopores (<100 nm) and are used as optical sensing devices for the detection of Volatile Organic Compounds (VOC). In the pursuit of simplicity, the compatibility of these sensors with Smartphone technology is emphasized; the final goal is to fabricate low-cost sensors with pronounced chemical selectivity that produce an optical signal directly readable by Smartphone cameras

碩士
國立成功大學
物理學系
107
This work simulates the Hong-Ou-Mandel (HOM) interference phenomenon by using the theoretical framework of the photon wave mechanics (PWM). Here, comparing with the creation operator and annihilation operator formalism of the quantum field theory (QFT), photon wave function (PWF) describes the photon state explicitly in the E+icB form, and the equation of motion obeyed is just the Maxwell’s equations in the classical electromagnetics. Therefore, the finite-difference time domain method is suitable for numerical calculations. The probability of the photon wave function is given in the form of non-local integral. This form requires the introduction of dual modes to form the biorthogonal basis system with the wave-packet mode, thus possessing the Lorentz-invariance. Therefore, their modulus square is interpreted as the local energy density. The two-dimensional beam splitter is designed in the mechanism of evanescent wave coupling. Through the numerical calculation, the medium refractive index of √3 ensures that the splitting effects of different incident modes are the same. After the simulation, the result is different from HOM experiment. But interestingly, its lower envelope matches the shape of the HOM dip. This work shows that the theoretical interest of PWM is not only for the completeness of theories or the demand of simulations, but also helping us to understand more deeply the properties of fundamental particles.

碩士
國立臺灣科技大學
資訊工程系
97
Current research toward solving personal photo management suffer from two problems: (1) lacking of training data, and (2) no consolidated reference for classification. In this thesis, we propose an automated annotation framework to address these problems. The framework is composed by three main components: the context information generator, the semantic concept detector, and the face identification model. Context information is extracted from the exif header file; semantic concept detector is trained by the Support Vector Machine (SVM); face recognition model is a combination of face detection and recognition. By assigning multi-labels for each photo, the framework makes the photo collection more structured and searchable. Our experimental results show that the techniques used in this framework are promising.

碩士
逢甲大學
資訊工程所
96
In public-key cryptography, the authentication of public keys is an essential topic for securing electronic data. The X.509 certification authority-based (CA) public key infrastructure (PKI) standard is a widespread solution which explicitly defines data formats and procedures related to the authentication of public key via public key certificates that are digitally sighed by CA. However, the formats of X.509 certificate contents, which consist of randomized integers and string data, are not friendly enough for human to directly associate the identities of real persons. To overcome this drawback, this thesis presents a framework for generating a kind of visualized certificate in image formats. We name this certificate as “photo certificate”. The fields of a certificate are classified into user identification data and program identification data according to their usage. Instead of describing in string data, photo certificate expresses user identification data by a visualized presentation form such as photos, logos, marks, etc. Furthermore, it utilizes watermarking technique for integrating user identification data and program identification data into an image format. We will implement photo certificate in bitmap format to prove that this framework is feasible.

Dissertação de mestrado em Engenharia Informática
Recent evolution of high performance computing moved towards heterogeneous platforms: multiple devices with different architectures, characteristics and programming models, share application workloads. To aid the programmer to efficiently explore these heterogeneous platforms several frameworks have been under development. These dynamically manage the available computing resources through workload scheduling and data distribution, dealing with the inherent difficulties of different programming models and memory accesses. Among other frameworks, these include GAMA and StarPU. The GAMA framework aims to unify the multiple execution and memory models of each different device in a computer system, into a single, hardware agnostic model. It was designed to efficiently manage resources with both regular and irregular applications, and currently only supports conventional CPU devices and CUDA-enabled accelerators. StarPU has similar goals and features with a wider user based community, but it lacks a single programming model. The main goal of this dissertation was an in-depth evaluation of a heterogeneous framework using a complex application as a case study. GAMA provided the starting vehicle for training, while StarPU was the selected framework for a thorough evaluation. The progressive photon mapping irregular algorithm was the selected case study. The evaluation goal was to assert the StarPU effectiveness with a robust irregular application, and make a high-level comparison with the still under development GAMA, to provide some guidelines for GAMA improvement. Results show that two main factors contribute to the performance of applications written with StarPU: the consideration of data transfers in the performance model, and chosen scheduler. The study also allowed some caveats to be found within the StarPU API. Although this have no effect on performance, they present a challenge for new coming developers. Both these analysis resulted in a better understanding of the framework, and a comparative analysis with GAMA could be made, pointing out the aspects where GAMA could be further improved upon.
A recente evolução da computação de alto desempenho é em direção ao uso de plataformas heterogéneas: múltiplos dispositivos com diferentes arquiteturas, características e modelos de programação, partilhando a carga computacional das aplicações. De modo a ajudar o programador a explorar eficientemente estas plataformas, várias frameworks têm sido desenvolvidas. Estas frameworks gerem os recursos computacionais disponíveis, tratando das dificuldades inerentes dos diferentes modelos de programação e acessos à memória. Entre outras frameworks, estas incluem o GAMA e o StarPU. O GAMA tem o objetivo de unificar os múltiplos modelos de execução e memória de cada dispositivo diferente num sistema computacional, transformando-os num único modelo, independente do hardware utilizado. A framework foi desenhada de forma a gerir eficientemente os recursos, tanto para aplicações regulares como irregulares, e atualmente suporta apenas CPUs convencionais e aceleradores CUDA. O StarPU tem objetivos e funcionalidades idênticos, e também uma comunidade mais alargada, mas não possui um modelo de programação único O objetivo principal desta dissertação foi uma avaliação profunda de uma framework heterogénea, usando uma aplicação complexa como caso de estudo. O GAMA serviu como ponto de partida para treino e ambientação, enquanto que o StarPU foi a framework selecionada para uma avaliação mais profunda. O algoritmo irregular de progressive photon mapping foi o caso de estudo escolhido. O objetivo da avaliação foi determinar a eficácia do StarPU com uma aplicação robusta, e fazer uma análise de alto nível com o GAMA, que ainda está em desenvolvimento, para forma a providenciar algumas sugestões para o seu melhoramento. Os resultados mostram que são dois os principais factores que contribuem para a performance de aplicação escritas com auxílio do StarPU: a avaliação dos tempos de transferência de dados no modelo de performance, e a escolha do escalonador. O estudo permitiu também avaliar algumas lacunas na API do StarPU. Embora estas não tenham efeitos visíveis na eficiencia da framework, eles tornam-se um desafio para recém-chegados ao StarPU. Ambas estas análisos resultaram numa melhor compreensão da framework, e numa análise comparativa com o GAMA, onde são apontados os possíveis aspectos que o este tem a melhorar.
Fundação para a Ciência e a Tecnologia (FCT) - Program UT Austin | Portugal

No
Recently, nanoscale metal-organic frameworks (NMOFs) have started to be developed as a promising platform for bioimaging and drug delivery. On the other hand, combination therapies using multiple approaches are demonstrated to achieve much enhanced efficacy. Herein, we report, for the first time, core-shell nanoparticles consisting of a photodynamic therapeutic (PDT) agent and a MOF shell while simultaneously carrying a chemotherapeutic drug for effective combination therapy. In this work, core-shell nanoparticles of zeolitic-imadazolate framework-8 (ZIF-8) as shell embedded with graphitic carbon nitride (g-C3N4) nanosheets as core are fabricated by growing ZIF-8 in the presence of g-C3N4 nanosheets. Doxorubicin hydrochloride (DOX) is then loaded into the ZIF-8 shell of the core-shell nanoparticles. The combination of the chemotherapeutic effects of DOX and the PDT effect of g-C3N4 nanosheets can lead to considerably enhanced efficacy. Furthermore, the red fluorescence of DOX and the blue fluorescence of g-C3N4 nanosheets provide the additional function of dual-color imaging for monitoring the drug release process.

This thesis offers dialogue about the relations between learning and Information and Communication Technologies (ICTs). The dialogue is guided by the question of how to design education to increase perceived values of learning. It pays attention to how learners approach learning availabilities in various learning settings based on learners’ perceived values of learning. The aim is to understand the perceived values of learning in order to reflect its relation to ICTs. The field of learning is understood from the perspectives of formal, non-formal and informal learning. The field of ICTs is understood from the perspectives of information, communication and technology. The perspectives of learning and ICTs are chosen as a way to understand them by ‘going back to basics’ to find an origin or a point of departure for reinterpreting and understanding them. This approach has influenced the presentation of the thesis and how it is structured so that dialogic and interpretive research opens up dialogic spaces for reflections regarding the relations between learning and ICTs. Two studies in two different education systems, formal and non-formal, are included in the thesis work. The data are collected via qualitative methods such as photo interviews and individual and group interviews in which learners’ expressions of learning are in focus. The approach of the included articles that present the two studies was to first understand learning and then relate it to the understanding, potential and use of ICTs. The results and contributions from the articles are summarised via the three perspectives of the perceived values of learning, the relations between learning and ICTs and the influences of perceived values of learning. The theoretical tools, pedagogical attitude and positioning of ICTs guide the discussions and analysis of these perspectives towards the conclusions of the thesis work. The reader of the thesis can expect a journey along a winding road, which both addresses and involves policies’ and researchers’ implications and conceptions of learning and education. A framework for the perceived values of education when perspectives of learning and ICTs are related is considered to represent the understanding of the coherent whole of the thesis work. Three main contributions of the thesis work are put forth. The first contribution is the framework for perceived values of education, or the perceived value framework (PVF). The second contribution is the understanding of perceived values of learning. The third contribution is the specific photo interviews about learning situations that is considered to be a contribution to already existing methods such as photo-eliciting (Cappello, 2005) and stimulated recall (Haglund, 2003).