Dissertations / Theses on the topic 'STEP-INDEX'

Coherent ultraviolet (UV) generation has various applications in a large number of fields, such as stand-off explosive detection, enhanced Raman scattering and photolithography, to name a few. Typically, the generation of coherent UV light relied on frequency doubling with nonlinear crystals and relatively complicated free space optics, on toxic gases (excimers) and low power UV diodes. In this thesis, the use of solid core step-index optical fibre for the generation of coherent UV radiation is investigated. Here, wavelength conversion in optical microfibres (OMFs) via nonlinear processes is considered. Firstly, efficient generation of UV radiation via intermodal third harmonic generation (THG) in fibres is first studied. While THG is potentially efficient in OMFs, it is not feasible in optical fibres with large numerical apertures. Detuning is found to be a critical parameter which determines the overall efficiency, thereby making the OMF diameter control crucial. Initial experiments indicate that the quasi-continuous wave (CW) sources with long pulses (a few ns) and high peak powers (∼ kW) are the most suitable for intermodal THG in OMFs, as detrimental nonlinear effects become dominant with ultrashort pulses. However, further theoretical investigations show that intermodal THG is fundamentally limited by the intrinsic surface roughness of the silica OMFs, restricting the maximum efficiency to ∼ 10^-3. This leads to the investigation of four wave mixing (FWM), where both parametric amplification and wavelength generation are theoretically investigated. A quasi-CW source working in conjunction with a periodically poled silica fibre (PPSF) is employed to investigate this experimentally, and it is shown that a scheme employing two OMFs allowed the generation of coherent UV radiation down to 0:31 μm, with fundamental limitations being imposed from losses due to the oxygen-deficiency centre inherent to the fibre.

This thesis focuses on the potential of compound-glass, highly nonlinear, small-core fibres for use in nonlinear applications. Both fibres with a conventional step-index design and small-core holey fibres are considered. While the former technology is more mature, the latter represents the ultimate candidate, since it offers the flexibility of combining novel dispersion properties with a very high nonlinearity. With regard to holey fibre designs, small-core, compound-glass holey fibres with different core diameters and designs are considered for two different background materials: a commercially available lead-silicate glass and a bismuth-oxide based glass. Firstly, characterization measurements are performed on the fabricated holey fibres. The measurements reveal the advantages of each glass type and each fibre design, the ultra-high nonlinearity that can be achieved in such fibres and the potential of achieving simultaneously a novel dispersion profile and high nonlinearity. Nonlinear applications are then demonstrated for some of the fibres presented. In particular, the use of a lead-silicate holey fibre, having a dispersion-shifted profile, with a zero-dispersion wavelength lying close to the C-band is demonstrated in cross-phase modulation based wavelength conversion and switching applications in the 1.55 μm window. Both a co-polarized pump and probe scheme and a Kerr-shutter configuration are considered. For the same fibre, the stimulated four-wave mixing process for amplification and wavelength conversion applications in the C-band is thoroughly studied. Numerical simulations and experimental findings are combined to study the fibre performance, demonstrate its applicability to nonlinear wavelength conversion applications and identify future improvement objectives. The suitability of compound-glass holey fibres is also examined for the generation of correlated photons, through spontaneous four-wave mixing, and the generation of a broad supercontinuum by pumping at the convenient in terms of high power laser availability wavelength regions of 1.0 μm and 1.5 μm. The experiments presented in this thesis constitute the first nonlinear applications ever reported for dispersion-tailored, compound-glass holey fibres, clearly revealing their potential in fibre-based nonlinear applications. Nonlinear applications are also demonstrated for a commercially available, fiberised, bismuth-oxide based fibre with a step-index design. Using this fibre, an all-optical regenerator of Return-to-Zero picosecond pulses is realized at repetition rates of 10 and 40 Gb/s. The same fibre is also employed in an all-fiberised pulse compression scheme, which relies on nonlinear pulse propagation in the normal dispersion regime and enables the compression of picosecond pulses down to the femtosecond scale. In both applications, the ultra high nonlinearity of the compound-glass, step-index fibre results in reduced fibre-length and peak power requirements. The thesis concludes by addressing the issues concerning the practicality of compound-glass fibres and proposing potential future directions.

Kunststofflichtwellenleiter (POFs) stellen ein verhältnismäßig neues Medium zur optische Datenkommunikation über kurzen Strecken dar. Während ihrer Einsatzdauer unterliegen POFs unterschiedlichen Arten von Umweltbeanspruchungen, hauptsächlich durch hohe Temperatur, hohe Feuchtigkeit und mechanischen Belastungen. Zahlreiche experimentelle Forschungen beschäftigten sich mit der standardisierten Prüfung der Zuverlässigkeit von im Handel erhältlichen Fasern. Jedoch gab es bisher wenig Erfolg bei der Bemühung, zwei grundlegende optische Erscheinungen, Absorption und Streuung, die die Lichtausbreitung in Fasern stark beeinflussen, zu verstehen und praktisch zu modellieren: Diese beiden Effekte beschreiben nicht nur die Qualität neuer Fasern, sondern sie werden auch stark durch die Alterungsprozess beeinflusst.

Der Hauptzweck dieser Doktorarbeit war es, ein praktisch verwendbares und theoretisch gut fundiertes Modell der Lichtausbreitung in nicht gealterten und gealterten POFs zu entwickeln und es durch optische Experimente zu verifizieren. Dabei wurden anwendungsorientierte Aspekte mit theoretischer POF-Modellierung kombiniert. Die Arbeit enthält die erste bekannte Anwendung der Wellenanalyse zur Untersuchung der winkelabhängigen Eigenschaften der Streuung in Lichtwellenleitern.

Für die praktischen Experimente wurden mehrere POF-Proben unterschiedlicher Hersteller künstlich gealtert, indem sie bis 4500 Stunden bei 100 °C gelagert wurden (ohne Feuchtekontrolle). Die Parameter der jeweiligen Simulationen wurden mittels einer systematischen Optimierung an die gemessen optischen Eigenschaften der gealterten Proben angeglichen. Die Resultate deuten an, dass der Übertragungsverlust der gealterten Fasern in den ersten Tagen und Wochen der Alterung am stärksten durch eine wesentliche physikalische Verschlechterung der Kern-Mantel-Grenzfläche verursacht wird. Chemische Effekte des Alterungsprozesses scheinen im Faserkernmaterial zuerst nach einigen Monaten aufzutreten.
This thesis discusses theoretical and practical aspects of modelling of light propagation in non-aged and aged step-index polymer optical fibres (POFs). Special attention has been paid in describing optical characteristics of non-ideal fibres, scattering and attenuation, and in combining application-oriented and theoretical approaches. The precedence has been given to practical issues, but much effort has been also spent on the theoretical analysis of basic mechanisms governing light propagation in cylindrical waveguides.

As a result a practically usable general POF model based on the raytracing approach has been developed and implemented. A systematic numerical optimisation of its parameters has been performed to obtain the best fit between simulated and measured optical characteristics of numerous non-aged and aged fibre samples. The model was verified by providing good agreement, especially for the non-aged fibres. The relations found between aging time and optimal values of model parameters contribute to a better understanding of the aging mechanisms of POFs.

This study has been carried out at Klättermusen, a Swedish company producing outdoor clothingand equipment with a focus on durability, safety, function and environment. The purpose of thethesis was to investigate if Klättermusen should use Cradle to Cradle (C2C) in their sustainabilitywork. This was reviewed by studying the working procedure, by making a case study, byinvestigating if there are alternative ways to practise C2C, by studying the weak points of theC2C-certification and by investigating the compatibility with other sustainability tools.The C2C vision is inspired by the ecosystems and is based on the three rules Waste equals food, Usecurrent solar income and Celebrate diversity. An important aspect of C2C is the focus on attaining apositive impact on humans and the environment instead of doing things less bad by minimizingemissions. To make it possible for companies to communicate their effort and progress to theircustomers and become more competitive a C2C certification has been elaborated. The core ofthe certification is an assessment of the materials included in the product to make sure they aresecure, healthy and recyclable. Other parts included in the certification are energy, water andsocial aspects.When studying the C2C certification three of Klättermusen’s products were used as references.To certify these products Klättermusen has to gather information from their suppliers and makestrategies regarding Materials, Material Reutilization, Energy, Water and Social Responsibility. Forexample all the substances that contained in the garment at a concentration of at least 0.01 %must be reported, which means that all suppliers must be requested to list their substances. Thecertification cost of a pair of pants investigated in this study was estimated to 54 500 €.An assessment was made to find alternative ways to practise C2C and identify weak points of theC2C certification. It is based on interviews held with Jenny Pfau working for EPEA and threepersons in contact with C2C in their work; Kjersti Kviseth, Magnus Hedenmark and RichardBlume. According to Jenny Pfau Klättermusen can practise C2C by making a screening, a detailedassessment or a workshop. Both Magnus Hedenmark and Richard Blume practise the frameworkof The Natural Step and think that the C2C certification should be used as a tool within theframework. Some weak points found by these persons in the certification are that it is timeconsuming,not transparent enough and lack of a systems perspective.The C2C certification was compared with bluesign, a sustainability standard for the textileindustry, and Eco Index, a sustainability tool made for the outdoor industry. The purpose was toinvestigate if the C2C certification is compatible with other tools and the compared aspects weremainly lifecycle stages, impact categories and level of detail, but also purpose, procedure,workload, required knowledge and experience, cost, credibility and transparency.Both strengths and weaknesses were found when studying the C2C certification. It has got apositive approach to sustainability and develops safe products from a chemical perspective buthas a lack of systems perspective, is costly and time-consuming. The compatibility of the toolswas discussed with the comparison as a basis. Eco Index is modular and could be adjusted tocomplement the C2C certification but both tools have a big workload. bluesign and the C2Ccertification include the same lifecycle stages but have different strengths, which could makethem complementing each but possibly contradictive.Klättermusen is recommended to make a sustainability vision of their future products and thenchoose which tools to use. Since Klättermusen is already a bluesign system partner it could be agood idea to complement bluesign with Eco Index and C2C, but this choice should depend onthe future vision.

Cette thèse traite du couplage de la simulation des grandes échelles (LES) à la propagation des ondes électromagnétiques dans la couche limite atmosphérique. La simulation de la couche limite de convection avec des nuages de faible altitude de type cumulus a été effectuée, et les donnés ont été post-traitées pour la propagation d’ondes électromagnétiques (EM) dans le domaine simulé. La première partie de la thèse porte sur la validation du code LES avec pour trois différentes types de conditions atmosphériques. Les données correspondants à la convection des nuages de faible altitude de type cumulus sont ensuite post-traitées pour obtenir les quantités temporelles d’intérêt pour la modélisation de propagation d’ondes EM. Ces quantités sont les suivantes: la distribution instantanée des indices de réfraction, paramètres locaux de la fonction de structure de l’index de réfraction, échelle caractéristique des structures les plus énergétiques, et échelle caractéristique des échelles dissipatives non résolues. La deuxième partie de la thèse porte sur l’application de ces quantités dans la modélisation de propagation de: ondes radio, ondes optiques, et tourbillons optiques. Une nouvelle méthode a été développée pour étudier la dispersion des ondes radio dans l’atmosphére turbulente. Cette nouvelle méthode établit l’ importance des fluctuations des grandes échelles sur les fluctuations de la phase des ondes radio. Il a été démontrée, via des exemples numériques, que le caractére instationnaire de ces quantités influesur la propagation des ondes optiques.

Difficulty in solving the discrete logarithm problem has led to its use in key exchange, public key cryptography and digital signatures. To measure the security of these algorithms, it is necessary to evaluate the methods currently available for attack. Although the applications of the discrete logarithm problem can be implemented in a variety of different groups, only implementations over multiplicative integers modulo a large prime p are considered. The object of this work is to review the current methods of solving the discrete logarithm problem - key exhaustion, Shanks' baby-step giant-step algorithm, Pollard's rho algorithm, the Silver Pohlig Hellman algorithm, index calculus methods and the general number field sieve. The resulting document contains all relevant mathematics, theorems and algorithms. As only one workstation is used, the problem will not be solved for large primes, but an indication of the relative strengths and weaknesses of each algorithm will be gained. Both the theoretical and practical issues were considered when comparing the attacks available. The algorithms were implemented using the computer algebra system "Magma", which was developed at the University of Sydney. Magma was chosen as it is a flexible package that is not restricted to group theory. The source code is included in Appendix B. The simplest methods to implement are key exhaustion, which relies on testing all possibilities, and the first improvement on this method - Shank's baby-step giant-step algorithm. Both methods are infeasible when the prime number is large. Pollard's rho algorithm, again impractical for large p, has the same expected running time as Shank's baby-step giant-step algorithm, but the storage requirements are negligible. The Silver Pohlig Hellman algorithm which is again impractical for a large p unless p-1 has small factors is also covered. Index calculus methods offer improvements in the time involved to attack the system, once the prime number becomes too large for the earlier methods. Unlike the previous algorithms, the index calculus methods are not generic, they can only be used for particular groups, one of which is the field GF(p ), considered here. The methods involve two parts, a costly precomputation stage that needs to be performed only once for each prime, and the calculation of the individual logarithm. Three methods are investigated - the first by McCurley, the second by Coppersmith, Odlyzko and Schroeppel, and the third by LaMacchia and Odlyzko. By attacking with these methods, primes with fewer than 200 bits are insecure and primes with less than 512 bits should be avoided. By adapting the general number field sieve to solve logarithms, the running time of the attack in some instances can be further improved. Unlike the index calculus methods, the time required for the precomputation and that required for the evaluation of the individual logarithm, are similar. This perhaps reduces the usefulness of the algorithm in the case where the same attack is to be implemented a number of times to determine several different logarithms. If the same prime is to be used for a number of attacks, it may be quicker to use an index calculus method as the precomputation is performed once and then the logarithms can be quickly calculated.

Bien que la propagation non-linéaire d'impulsions multimodales ait été étudiée dans les fibres optiques multimodes depuis les années 1970, les récents développements dans le domaine des matériaux et des techniques de fabrication des fibres ont considérablement renouvelé l'intérêt pour ce domaine. Dans cette thèse, nous rapportons l'étude expérimentale du processus de conversion non-linéaire de fréquence dans les fibres à saut d'indice multimodes pour générer de nouvelles composantes spectrales dans les régions du proche ultraviolet (UV-A) et du visible. Deux études particulières ont été réalisées. Dans la première, une fibre à saut d'indice faiblement multimode a été étudiée avec deux sources laser à 532~nm et 1064~nm. En fonction des particularités des conditions expérimentales, les résultats obtenus avec le pompage à 532~nm ont donné soit un large continuum multimode s'étendant de 515~nm à 680~nm, soit une série de composantes spectrales discrètes émises dans des modes d'ordre supérieur sur la plage de 524~nm à 538~nm. De plus, toujours en fonction des conditions expérimentales, lors du pompage à 1064~nm, les expériences ont donné soit un supercontinuum multimode s'étendant de 560~nm à 2350~nm, soit une série de pics spectraux discrets dans des modes d'ordre supérieur observés simultanément avec un élargissement spectral continu. Dans la seconde étude, les expériences ont porté sur la conversion non-linéaire de fréquences dans une fibre à cristaux photoniques en verre de silice spéciale UV avec pompage à 532~nm et 355~nm. Les résultats du pompage à 355 nm, en particulier, ont permis de générer des pics spectraux discrets d'ordre supérieur sur la plage 350~nm à 379.7~nm. D'autres expériences avec une injection dans les ponts de la microstructure de la fibre à cristaux photoniques ont permis d'obtenir un continuum en cascade Raman s'étendant de 350~nm à 390~nm. Les travaux expérimentaux de cette thèse ont été accompagnés soit de calculs théoriques des accords de phase intermodaux, soit de simulations de la propagation d'impulsions dans une fibre optique, si nécessaire. Cette thèse contribue à l'ensemble croissant de résultats montrant l'utilité des effets non-linéaires dans les fibres multimodes pour générer un rayonnement cohérent sur de larges plages spectrales
Although multimode non-linear propagation has been studied in multimode optical fibres since the 1970s, recent developments in materials and manufacturing techniques have greatly renewed interest in this area. In this thesis, we report the experimental study of nonlinear frequency conversion processes in multimode fibres to generate new spectral components in the near ultraviolet (UV-A) and visible spectral regions. Two particular studies have been carried out. In the first, a few-mode step-index fibre was studied with two pump laser sources at 532~nm and 1064~nm. Depending on the particular experimental conditions, the results with 532~nm pumping yielded either a broad multimode continuum spanning over 515--680~nm, or as series of discrete spectral components emitted in particular higher-order modes over the range 524--538~nm. And again depending on experimental conditions, when pumping at 1064~nm, experiments yielded either a broadband multimode continuum spanning over 560--2350~nm, or a series of discrete spectral peaks in higher-order modes observed simultaneously with continuous spectral broadening. In the second study, experiments studied nonlinear frequency conversion in a UV-grade silica glass photonic crystal fibre with pumping at 532~nm and 355~nm. Results for 355~nm pumping in particular yielded the generation of higher-order mode discrete spectral peaks over the range 350--379.7~nm. Additional experiments pumping the photonic crystal fibre microstructure cladding region yielded a Raman cascade continuum spanning 350--390~nm. The experimental work in this thesis was accompanied by theoretical calculations of intermodal phase matching, or simulations of pulses propagation in an optical fibre as required. This thesis contributes to the growing body of results showing the utility of nonlinear effects in multimode fibre to generate coherent radiation over broad spectral ranges

The direct agreements perform an essential role in the viability of financing of projects. Its proper regulation determines its course, the prevention and management of possible consequences. Therefore, it is important to know this legal concept that has scarcely been studied in the doctrine. In this article, the author develops legal treatment of this legal concept, its definition, main terms and regulation in the Peruvian legal system.
Los contratos directos desempeñan un rol esencial en la viabilidad de la financiación de proyectos. Su adecuada regulación determinará el curso de los proyectos, la prevención y el manejo de posibles consecuencias. Por ello, es importante conocer esta figura jurídica que ha sido poco estudiada en la doctrina. En el presente artículo, el autor desarrolla el tratamiento legal de esta figura jurídica, su definición, sus principales términos y su regulación en el ordenamiento jurídico peruano.

This article is a casuistry review of technical reports of several filesregarding applications of patent of invention, in the technological fields of biotechnology, pharmaceutics, chemistry and engineering, where in general and specific criteria are identified and extracted on the requirements of clearness and inventive step that are evaluated in the technical report for obtaining a patent of invention in Peru.It is important to note that prior to the review of the investigated technical reports, certain definitions are provided for understanding the requirements of the technical report, such as conciseness, clearness, sufficiency, novelty and inventive step.
El presente artículo es una revisión casuística de informes técnicos de diferentes expedientes de solicitudes de patentes de invención en los campos tecnológicos de la biotecnología, farmacia, química e ingeniería, donde se identifican y extraen los criterios generales y específicos sobre los requisitos de claridad y nivel inventivos que se evalúan en el examen técnico para la obtención de una patente de invención en el Perú.Es importante señalar que previo a la revisión de los informes técnicos investigados, se brindan algunas definiciones para la compresión de los requisitos del examen técnico, tales como concisión, claridad, suficiencia, novedad y nivel inventivo.

Le traitement de boues de station d'épuration (Boues activées de Marrakech) en mélange avec déchets verts (Palmier dattier) selon deux mélanges dont les proportions : A (1/3 Boues + 2/3 Déchets de palmier) et B (1/2 Boues + 1/2 Déchets de palmier), a été effectué par la filière du compostage, pendant six mois. Au cours du co-compostage, l’intense activité microbienne s’est traduite par une augmentation de température (autour 65 C°) au cours des premières semaines (phase thermophile) et un taux de décomposition final de l’ordre de 40%. Après six mois de co-compostage, le compost final est caractérisé par un rapport C/N voisin de 10, un rapport de NH4+/NO3- < 1, un pH autour de la neutralité signe de maturité des composts. L’analyse FTIR a montré une diminution de l'absorbance des bandes aliphatiques et l'augmentation de la structure de bandes d'absorbance aromatiques reflètent l'état d'avancement du processus d'humification. Le taux d’abattement des lipides totaux est de l’ordre de 43%. Les esters méthyliques d’acide gras (FAMEs) des Gram-positif (i,C15 :0) ont augmenté durant la phase thermophile. Les FAMEs d’origine non spécifique (C6 :0, C14 :0) ont connu une intense diminution, les FAMEs de bactéries non spécifiques représentent une grande teneur durant la phase thermophile. L’indice CPI a augmenté à la fin du co-compostage indiquant l’enrichissement du compost en FAMEs d’origine végétale. Les principaux composés ligneux identifiés, au cours du co-compostage, par Py-GC-MS, sont classés en deux groupes. Le premier est constitué de 7 composés dont la teneur diminue au cours du co-compostage, parmi lesquels : Toluène, 2,4-diméthylbenzène, éthylbenzène, Styrène, 1-éthyl-2-méthylbenzène, 4-méthylphénol et 2-méthylnaphthalène. Le deuxième groupe est constitué de 4 composés qui augmentent au cours du co-compostage : phénol, benzofuran, éthylméthoxyphénol et diméthoxyphénol. Les principaux stéroïdes identifiés sont les C27-C29 sterènes, stanols, 5β-cholesta-3-one, cholesta-3,5-diène et 2 thiostéranes. A l’exception des thiosteranes et quelques composés de C27-C29 cholestenes la concentration relative des stéroides diminue au cours du processus suit à leur attaque microbien. L’abattement total de la teneur des stéroïdes est corrélé positivement avec les indicateurs de maturité du compost (C/N et NH4+/NO3-) ce qui ouvre la voie à une éventuelle utilisation des stéroïdes comme indicateur de dépollution et de maturité de compost. 12 isolats d’actinomycètes ayant une activité antimicrobienne vis-à-vis d’un large spectre des germes pathogènes ont été isolés sur le milieu sélectif CTEA. Le degré d’hygiénisation est confirmé par la diminution de la concentration des coliformes fécaux et totaux, et l’abattement des œufs d’helminthes identifiés (Ascaris sp., Capillaria sp., et Trichuris sp.) vers la fin du co-compostage. La phytotoxicité, déterminée par l’effet des extraits hydrosolubles à différents stades de co-compostage sur la germination et la croissance des radicules (Navet, Cresson, Laitue, Luzerne), a diminué et l’indice de germination dépasse 100%, après six mois de co-compostage. La génotoxicité du chrome hexavalent (Cr(VI)) du substrat de co-compostage est corrélée positivement avec la fréquence des micronoyaux (MN). Après six mois de co-compostage le taux des MN diminue avec un taux d’abattement de 70,4% et 77,2% avec l’abattement de la concentration du Cr(VI) avec 58 et 58,6% respectivement pour le mélange A et B. Ceci ouvrira la voie d’utilisation de cet indice comme un indice de maturité des composts. La diminution de la phytotoxicité et la génotoxicté au cours du co-compostage confirme l’état de stabilisation et de la maturité des co-composts, ce qui pemettra l’épandage de ces composts en tant qu’amendement organique des sols sans risque de contamination du système sol-plante
The co-composting of activated sludge and lignocellulose waste (palm tree waste) was monitored to study the behaviour of two mixtures, referred to as A (1/3 sludge + 2/3 palm waste) and B (1/2 sludge + 1/2 waste palm) for 6 months. The biotransformation was evaluated by physicochemical and spectroscopic analyses. The thermophilic phase is characterized by a rise in temperature, which peaked at 65°C. This is the result of intense microbial activities. The final composts exhibited a higher degree of decomposition than the controls as shown by a decomposition rate of about 40%, decrease of C/N ratio to around 10 and NH4 +/NO3 - ratio below 1. The decrease of aliphatic absorbance bands and the increase of aromatic absorbance bands follow the progress of the humification process. Total extractable lipid was decreased by 43%. The fatty acid methyl esters (FAMEs) from Gram-positive bacteria (i, C15: 0) increased during the thermophilic phase. FAMEs from non-spécific origin (C6 :0, C14 :0) exhibited a decrease toward the end of co-compostin, linear FAMEs from non-specific bacteria underwent a decrease during co-composting. The CPI index thus increased at the end of the composting process, indicating that the final product was proportionally richer in fatty acids of plant origin. Two lignin groups were distinguished by Py-GC-MS. Group 1 contained toluene, 2,4-dimethylbenzene, ethylbenzene, styrene, 1-ethyl-2-methylbenzene, 4-methylphenol and 2-methylnaphthalene; their relative proportions decreased during co-composting. A second group of 4 components showed concentrations that increased with co-composting time: phenol, benzofuran, ethylmethoxyphenol and dimethoxyphenol. The main steroids identified were C27-C29 sterenes and stanols, 5β-cholesta-3-one, cholesta-3,5-diene and 2 thiosteranes. Except for thiosteranes and some of the C27-C29 cholestenes, the relative concentrations decreased during co-composting due to microbial degradation. The changes in steroids during co-composting, was positively correlated with the physico-chemical parameters of mature compost, especially C/N and NH4 +/NO3 - ratios, opening the way for the use of steroids as indicators of pollution and compost maturity. On the selective CTEA medium, 12 active strains of isolated actinobacteria presented a suppressive action against various pathogens. This may justify that a biotic factor is also an important factor contributing to making co-composting substrates hygienic. The degree hygiene reached is confirmed by the reduction in the faecal and total coliforms, and by the abatement of identified helminth eggs (Ascaris sp., Capillaria sp., and Trichuris sp.) towards the end of the process. The phytotoxicity determined by the effect of aqueous extract, at various stages of the co-composting, performed by monitoring the number of germinated seeds and the rootlets growth of turnip, watercress, alfalfa, and lettuce was decreased, and the growth of radicals that have a germination index that exceeds 100% after six months of co-composting. Hexavalent chromium (Cr(VI)) genotoxicity showed a positive correlation with micronucleus (MN) frequency. After six months of co-composting, the MN rate decreased significantly by 70.4 and 77.2% with decreasing Cr(VI) concentration with 58 and 58.6%, for mixtures A and B respectively. That indicates their suitability for use as a maturity index. During co-composting the abatement rate of phytotoxicity and genotoxicity confirme the maturation and stabilization degree of co-composting end products which encourages their recycling in agriculture as a fertilizer for the soil without any contamination of the soil-plant system

碩士
國立雲林科技大學
工業設計系碩士班
100
Running is the most common exercise which is beneficial to healthy. It has become popular since 1970, more and more people began to running. Running was no longer considered just a habit, but was considered to be the key to keep life well. How to make running more healthier for all the mankind is always a goal we searched for. The study was investigated the effects of physical index of running by three experiments. The first experiment was estimated plantar maximum force and peak pressure when running barefoot and shod land on the rear-foot strike (RFS) and fore-foot strike (FFS) on the ground of jigsaw mats, pu track, marble and asphalt. The study results can be summarized as following: 1.In conculsion, plantar maximum force and peak pressure were greater when running on the harder ground material. 2.Running shod or barefoot land on RFS and FFS on rigid ground, there is greater maximum force at rearfoot and RFS greater than FFS. 3.Running on the jigsaw mats and asphalt, shod RFS has greater maximum force than barefoot RFS at rear-foot. 4.Running shod or barefoot on rigid ground, there are greater peak pressure at rearfoot, medial forefoot and middle forefoot. 5.Running on the jigsaw mats, shod has greater peak pressure than barefoot at medial forefoot and middle forefoot. 6.RFS has greater maximum force and peak pressure than FFS at rearfoot；FFS has greater maximum force and peak pressure than RFS at medial forefoot and middle forefoot. 7.Barefoot has greater peak pressure than shod at medial midfoot and lateral midfoot； shod has greater maximum force than Barefoot at rearfoot, lateral forefoot and hallux. The second experiment was estimated the variations of relative bloodflow, heart rate and respiration rate when running in 125%, 115%, 100%, 85% and 75% steps at the same speed. The study results show that respiration and heartbeat become faster and relative bloodflow become smaller, but there were no significant in heart rate when increase or decrease the running steps at the same speed. The last experiment was estimated the effects of arm and leg strength on running curve. The study results show that people who have greater strength at right arm and right leg, greater right arm pull strength and right dominant leg was faster when running left curve；people who have greater strength at left arm and left leg, greater left arm pull strength and left dominant leg was faster when running right curve.

In the past decade, great research effort was inspired by the need to realise purely optical communication systems, so came the need and application of active optical functionalities. This thesis focuses on a numerical modelling for slow light generation based on stimulated Brillouin scattering for bismuth oxide step index fibre for single mode operation. We have selected a wave-length of 1550nm for our thesis. The approach to acquiring slow light in optical fibre is based on the phenomena of stimulated Brillouin scattering. Slow light phenomenon is to drastically decrease the velocity of light as it travels through certain media. Slow light can be generated via various methods like stimulated Raman scattering (SRS), stimulated brillouin scattering (SBS), electromagnetically induced transparency (EIT), coherent population oscillation (CPO), etc but here we are focusing on stimulated brillouin scattering. For the proposed optical fibre structure, we have obtained affective mode area and confinement loss. A time delay of 104.45 ns has been achieved for the maximum permissible pump power of 976 mW with the Brillouin gain of 90.38 dB and figure of merit of 45.29 at 500 mW pump power. It is observed that time delay can be tuned with input pump power and length of the proposed ridge waveguide. Such tunable features of the slow light can have potential applications in realization of an all-optical network. The proposed structure is analysed by the finite element method using software COMSOL Multiphysics and MATLAB.

碩士
國立臺灣科技大學
高分子工程系
93
This study investigated the optimization of processing that the Fluoro copolymer for the cladding material of plastic optical fiber cover the core material which include Poly methyl methacrylate (PMMA), Poly Carbonate（PC）, Poly Styrene（PS）and ARTON, ZEONEX, TOPAS of Metallocene Cyclic Olefin Copolymer (MCOC ) series plastic product in plastic optical fiber sample transmission loss and research its mechanism . The result shows that select proper core material TOPAS of MCOC series plastic product to match the cladding material which made up of the plastic optical fiber sample and the optimization of processing methods to process the SI type plastic optical fiber. It is transmitted under the wavelength 660nm and 850nm of light source can make people very surprised which the low transmission of plastic optical fiber. It can obvious that transmission loss lower PMMA, PC, PS of core material which made up the plastic optical fiber .In order to understand these above-mentioned low transmission loss behavior of the plastic optical fiber. The plastic optical fiber that resisting tensile mechanics, polymer basic rheological behavior, dynamic mechanical properties of polymer, thermal properties and morphology of cross-section was further discussed in this study.

碩士
淡江大學
統計學系碩士班
106
Process capability indices are commonly used to measure process potential and performance. Most of the process capability indices assume the lifetime of products are normally distributed. However, the lifetime of products generally may possess an exponential, Weibull or Rayleigh distribution. Additionally, high reliability makes it difficult to obtain failure products. Accelerate life- testing has often been used to yield information quickly. In this paper, we assume the lifetime of products are Rayleigh distributed, using step-stress accelerated life-testing to obtain failure products to construct the maximum likelihood of lifetime performance index, C ̂_L, and the asymptotic distribution of C ̂_L. Given the lower specification limit, L, using the confidence interval of C ̂_L to construct hypothesis tests process to determine whether the lifetime performance reaches the expected level. Two examples are simulated to explain how the method in this paper work. Finally, Monte Carlo method are used to simulate the lifetime of products, calculating the coverage rate of the confidence interval of C_L, mean square error of C ̂_L and the average testing time to assess the result.

碩士
國立彰化師範大學
電機工程學系
107
The thesis mainly applies a multi-step index (MSI) fiber and arc-branch structure to the design and research of a Y-junction coupler in a distributed illumination system. Generally, an optical fiber illumination system usually needs to combine multiple light-source beams into one beam or divide one beam into multiple beams, and the used beam combining or splitting elements are usually the Y-junction coupler. In previous researches, most of couplers were designed and fabricated with a single material of step-index (SI) fibers; however, the efficiency of the couplers is declined due to the susceptibility of a taper region formed by multi-branch stacks. Therefore, this thesis uses a MSI plastic optical fiber (POF), which is similar to a graded-index (GRIN) fiber having property of self-focus, to design the Y-junction coupler and improve the light loss caused by the taper region so that the coupling efficiency can be increased, the output beam-angle becomes more convergent, and the size of the coupler is greatly reduced. Optical simulation results show that the combining and splitting efficiencies of the MSI-POF Y-junction coupler designed in this thesis can reach 74 and 85%, respectively, and corresponding minimum output half-beam angles can be respectively reduced to 67 and 45% of the original half source-beam angle. As compared with a high efficient SI-POF Y-junction coupler, the MSI-POF Y-junction coupler has good coupling efficiency even at a smaller bending radius, and the associated convergence angle is less than that of the SI-POF coupler even up to 78% that the volume of the coupler can be greatly reduced.

碩士
國立臺灣科技大學
高分子工程系
94
In this study, we discussed the rheologic properties of poly carbonate(PC)、poly methyl methacrylate(PMMA)、poly styrene(PS) and ARTON、TOPAS and ZEONEX of metallocene cyclic olefin copolymer(MCOC) series as core material and fluoro copolymer(THV) as cladding material making plastic optical fiber at first. Then according to the data measured by rheometer, we got the correlation suitable for complex fiber-spinning machine after calculation from formula. Furthermore, we investigated the relationship of transmission loss and core/cladding shear viscosity under the optimization of processing. The result shows the minimum of transmission loss corresponding different core/cladding shear viscosity with different core material. In order to understand the behavior of plastic optical fiber, their ultra-red, ultraviolet and visible light absorption spectrum, haze and the cross-section morphology were also discussed further.

A new multi-step self-assembly route to polymer-semiconducting nanoparticle photonic structures is described. The multi-step self-assembly strategy targets complex hierarchical structures in which organization of cadmium sulfide (CdS) nanoparticles on progressively longer length scales is introduced via a series of three self-assembly steps. each involving building blocks of increasing structural complexity. Each self assembly step can be described as follows: 1) SA1: self-assembly of PS-b-PAA to form block ionomer reverse micelles, followed by synthesis of a single CdS semiconducting nanoparticle in each core, forming the hybrid building blocks PS-CdS: 2) SA2: self-assembly of blends of PS-CdS and PS-b-PAA stabilizing chains in DMF/water mixtures by addition of water to form spherical nanoparticle assemblies, termed large compound micelles (LCMs); 3) SA3: self-assembly of LCMs into ordered close packed arrays by slow water evaporation. The kinetic freezing of building blocks at each stage offers the potential for unique control of nanoparticle self-assembly step since each step is "locked in", allowing structural features determined by the subsequent step to be independently tuned through a new set of experimental variables. Chapter 2 and 3 of this thesis investigate aspects of size and polydispersity control of spherical nanoparticle assemblies in the SA2 self-assembly step. Chapter 4 demonstrates that LCMs can be further assembled (SA3 step) to form three-dimensional hierarchical arrays.

The literature suggests that many teachers are burning out and are stressed and unwell. Health promotion in the school setting with a focus on students is becoming more and more prevalent. However, research has not adequately investigated the effects of health promotion in the school setting focused on the teachers. This study explores the experiences of the teachers who took part in the “Step It Up” program which is a pedometer program including goal setting and teams. This is a mixed methodology as the data was collected using semi structured interviews, open ended questionnaires and a document review of the step logging records. Interviews were transcribed and analyzed according the Colaizzi procedures seeking the barriers and the benefits of the program as experienced by the teachers. Through data analysis, the benefit main themes were; motivation, awareness and social support. The barrier themes found were; step logging, time management and goal setting. In conclusion with the recommendations and modifications suggested in this study, the “Step it Up” program is feasible in the school-setting.

The literature suggests that many teachers are burning out and are stressed and unwell. Health promotion in the school setting with a focus on students is becoming more and more prevalent. However, research has not adequately investigated the effects of health promotion in the school setting focused on the teachers. This study explores the experiences of the teachers who took part in the “Step It Up” program which is a pedometer program including goal setting and teams. This is a mixed methodology as the data was collected using semi structured interviews, open ended questionnaires and a document review of the step logging records. Interviews were transcribed and analyzed according the Colaizzi procedures seeking the barriers and the benefits of the program as experienced by the teachers. Through data analysis, the benefit main themes were; motivation, awareness and social support. The barrier themes found were; step logging, time management and goal setting. In conclusion with the recommendations and modifications suggested in this study, the “Step it Up” program is feasible in the school- setting.

Fully turbulent inflow past symmetrically located side branches mounted in a duct can give rise to pronounced flow oscillations due to coupling between separated shear layers and standing acoustic waves. Experimental investigation of acoustically-coupled flows was conducted using digital particle image velocimetry (DPIV) in conjunction with unsteady pressure measurements. Global instantaneous, phase- and time-averaged flow images, as well as turbulence statistics, were evaluated to provide insight into the flow physics during flow tone generation. Onset of the locked-on resonant states was characterized in terms of the acoustic pressure amplitude, frequency and the quality factor of the resonant pressure peak. Structure of the acoustic noise source is characterized in terms of patterns of generated acoustic power. In contrast to earlier work, the present study represents the first application of vortex sound theory in conjunction with global quantitative flow imaging and numerical simulation of the 2D acoustic field. In addition to the basic side branch configuration, the effects of bluff rectangular splitter plates located along the centerline of the main duct was investigated. The first mode of the shear layer oscillation was inhibited by the presence of plates, which resulted in substantial reduction of the amplitude of acoustic pulsations and the strength of the acoustic source. These results can lead to the development of improved control strategies for coaxial side branch resonators. Motivation for the second part of this study stems from the paper manufacturing industry, where air clamp devices utilize high-speed jets to position paper sheets with respect to other equipment. Thus, vibration of the paper sheet and turbulent flow that emerged from a planar curved nozzle between a flexible wall and a solid surface containing a backward-facing step (BFS) were investigated using high-speed photography and DPIV, respectively. The emphasis was on the characterization of the flow physics in the air clamp device, as well as of the shape of the paper sheet. For the control case, that involved a solid wall with a geometry that represented the time-averaged paper profile, hydrodynamic oscillation frequencies were characterized using unsteady pressure measurements. Experimentally obtained frequencies of the paper sheet vibration were compared to the hydrodynamic frequencies corresponding to the oscillations of the shear layer downstream of the BFS.

The vegetation of the Nooitgedacht section of the Loskop Dam Nature Reserve resembles Bankenveld vegetation and differs from the other areas of the reserve. This study was undertaken to identify, classify, and describe the plant communities present on this section, and to determine their veld condition. The Braun-Blanquet approach was followed to classify the different plant communities. A total number of 170 sample plots (100m2) were placed in all homogeneous vegetation units in a randomly stratified basis. The Ecological Index Method (EIM) was used to determine the veld condition. Data were collected using the steppoint method and incorporated into the GRAZE model from where the veld condition was calculated. A minimum of 400 step points were surveyed in each community with more points in the larger communities. Plant community data was analysed using the JUICE software program. A total of 11 plant communities were identified. The overall veld condition score indicates the vegetation to be in a good condition, resulting in a high grazing capacity.
Environmental Sciences
M. Sc. (Nature Conservation)