During the last decade, the maximum capacity of an optical fiber transmission line more than doubled every year to match the fast-growing communication need. The technology break through in dry fiber fabrication opens the possibility for fiber bandwidth all the way from 1300 nm to 1600 nm. The fast increasing demand of communication capacity results in the emergence of wavelength division multiplexing (WDM) technology, enabling tens of channels with different wavelengths transmitted simultaneously on an optical fiber. In consequence, it raises the requirement of spectral bandwidth of all the optical components used in the optical transport networking systems. Cr4+:YAG has potential to meet this demand because its 3T2¡÷3A2 transition has a strong spontaneous emission that just covers the low-loss window of optical fiber. The crystalline host offers a excellent mechanical characteristic. Such a fiber is, therefore, eminently suitable for super-wideband optical source since the required pump power is expected to be higher. We have successfully demonstrated a diode-laser pumped Cr:YAG crystal fiber ASE light source. The crystal fibers are grown by the laser-heated pedestal growth technique. Using a 46.6 mm-long Cr:YAG single crystal fiber of a 3-dB ASE width of 265 nm and a power spectral density ¡V22.1 dBm/nm was achieved. In the future, to further increase the quantum efficiency and output power we will reduce the core diameter, lengthen the fiber, increase the Cr4+ doping concentration, fabricate double-cladding, coat the fiber facets, and improve the cooling system.

Permanent dielectric materials are integral to the fabrication of microelectronic devices and packaging. Dielectrics are used throughout devices to electrically and mechanically isolate conductive components. As such, they are required to have low electrical permittivity and robust mechanical properties. For packaging applications, dielectrics can be directly photo-definable. Dielectrics need to have excellent lithographic properties. These properties are pivotal for enabling high yield and low cost fabrication of reliable, energy efficient devices. The aim of this work was to develop new positive tone dielectrics which have improved or application-specific lithographic, mechanical, and electrical properties. To this end, several new dielectric polymers and chemistries were evaluated and characterized. Initially, it was desired to develop a positive tone, polynorbornene (PNB) dielectric that utilizes diazonaphthoquinone (DNQ) photochemistry. Cross-linking was achieved with epoxy cross-linkers during a thermal cure. Several DNQ-containing compounds were evaluated, but only one had good miscibility with PNB. The dissolution characteristics of PNB were measured with respect to polymer composition, DNQ loading, and cross-linker loading. PNB films exhibited unique dissolution properties, and these measurements allowed for an optimum formulation to be developed. A formulation with 20 pphr DNQ and 10 pphr epoxy cross-linker had sufficient inhibition in unexposed regions and fast dissolution in exposed regions. The resulting dielectric was the first positive tone, DNQ-based PNB dielectric. After achieving photo-definability, the cross-linking of the cured dielectric was evaluated by characterizing the mechanical properties. It was discovered that DNQ acted as a cross-linker in these films, and this insight was key to achieving good curing of the dielectric. Several experiments were performed to support this conclusions, and the reaction kinetics of this cross-linking reaction were evaluated. This effort produced a functional, positive tone dielectric with a sensitivity of 408 mJ cm-2 and contrast of 2.3. The modulus was 2.0 to 2.6 GPa and the dielectric constant of 3.7 to 3.9, depending on the curing conditions. The DNQ cross-linking results led to the investigation of other cross-linking chemistries for positive tone dielectrics. A chemically amplified (CA) photochemistry was utilized along with a Fischer esterification cross-linking reaction. Patterning and cross-linking were demonstrated with a methacrylate polymer. Successful positive tone lithography was demonstrated at a high sensitivity of 32.4 mJ cm-2 and contrast of 5.2. Cross-linking was achieved at 120°C as shown by residual stress and solubility measurements. The CA photochemistry and Fischer esterification cross-linking were also demonstrated using a PNB dielectric, which was shown to have improved lithographic properties: a sensitivity of 8.09 mJ cm-2 and contrast of ≥ 14.2. Work was performed to evaluate the effect of the polymer composition on the mechanical and electrical properties. A polymer with 60 mol% hexafluoroisopropanol norbornene and 40 mol% tert-butyl ester norbornene exhibited a dielectric constant of 2.78, which is lower than existing positive tone dielectrics. It also outperformed existing dielectrics in several other categories, including dark erosion, volume change, cure temperature, and in-plane coefficient of thermal expansion. However, a limitation of this dielectric was cracking in thick films. The final study was to improve the mechanical properties of this CA PNB dielectric specifically to enable 5 µm thick films. First, a terpolymer was tested that included a non-functional third monomer. The dielectric constant increased to 3.48 with 24 mol% of the third monomer. Second, low molecular weight additives were used to lower the modulus. Only one of the five tested additives enabled high quality, thick films. This additive did not significantly affect the dielectric constant at low loadings. An optimized formulation was made, and processing parameters were studied. The additive decreased the lithographic properties, lowering the sensitivity to 175 mJ cm-2 and lowering the contrast to 4.36. In all, this work produced three functional dielectrics with positive tone photo-definability and good lithographic properties. Each dielectric can serve a variety of purposes in microelectronics packaging.

Position and navigation of vehicle in two and three dimensions have been important as being advanced technology. Therefore, some system has been evaluated to get information of vehicle&rsquo / s position. Main problem in navigation is how to determine position and rotation in three dimensions. If position and rotation is determined, navigation will also be determined with respect to their initial point. There is a technology that vehicle velocity can be discovered, but a technology that rotation can be discovered is needed. Sensor which sense rotation is called gyroscope. If this instrument consists of optical and solid state material, it&rsquo / s defined by Fiber Optic Gyroscope (FOG). There are various studies in order to increase the sensitivity of fiber optic gyroscopes, which is an excellent vehicle for sensing rotation. One of them is interferometric fiber optic gyroscope with amplified optical feedback (FE_FOG). In this system, a feedback loop, which sent the output pulse through the input again, is used. The total output is the summation of each interference and it is in pulse state. The peak position of the output pulse is shifted when rotation occurs. Analyzing this shift, the rotation angle can be determined. In this study, fiber optic gyroscopes, their components and performance characteristics were reviewed. The simulation code was developed by VPIsystems and I used VPItransmissionMakerTM software in this work. The results getting from both rotation and nonrotation cases were analyzed to determine the rotation angle and sensitivity of the gyroscope.

Amplified fragment length polymorphism (AFLP) markers allow a rapid assessment of the level of genetic variation that would be difficult to evaluate using a limited number of morphological markers. AFLP was used to assess the level of genetic variation among 16 different Phalaenopsis species and hybrids. Ten AFLP primer combinations were used for genetic analysis of these Phalaenopsis and 95% of polymorphism in 16 Phalaenopsis species and hybrids was detected. The genetic similarity among Phalaenopsis species and hybrids ranged from 0.298 to 0.774 based on Dice coefficient. The dendrogram derived by UPGMA analysis clustered into two main groups. A significant linear relationship (r² = 0.524, P < 0.0001) was observed between known pedigrees and AFLP-derived genetic similarity for 136 pairwise comparisons of Phalaenopsis species and hybrids. The results indicate that there is an abundance of genetic diversity among within Phalaenopsis and that AFLP can be used to distinguish morphologically similar genotypes. In a second study, the effect of gametophytic selection on genetic diversity in Phalaenopsis was examined by AFLP analysis. Sixteen F1 seedlings resulting from cross-pollination that occurred within high (30 ºC) and low (14 ºC) temperature incubators between two hybrid Phalaenopsis [P. (Taisoco Windian à Sogo Yukidian) by P. hybrid unknown], were subjected to genetic analysis by AFLP. A total of 651 fragments ranging in size from 100 to 350 bp were detected using six primer combinations, of which 387 (59.4%) were polymorphic. Seedlings derived from different temperature treatments exhibited 25.5% to 35.9% polymorphism. The genetic similarity among 16 F1 seedlings ranged from 0.825 to 0.946 based on the Dice coefficient. A dendrogram based on 387 polymorphic markers was derived by UPGMA analysis resulting in three major groups and one subgroup. The dendrogram analysis showed clear clustering in Phalaenopsis hybrids pollinated under different temperature treatments, suggesting that several loci may have been selected during the divergent temperature stress treatments during pollination and early pollen tube growth. / Master of Science

Im ersten Teil der Arbeit wurde die random amplified polymorphic DNA (RAPD) Methode für die Anwendung humaner DNA optimiert, indem die Konzentrationen der einzelnen Agentien und das thermische Profil der PCR-Reaktion verändert wurden. Des weiteren wurde der Einfluss von Polymerasen und PCR-Maschinen auf die RAPD, insbesondere auf die Erweiterung des Spektrums der Amplimere und die Reproduzierbarkeit der Reaktionen untersucht. Unsere Untersuchungen haben gezeigt, dass die RAPD eine sehr robuste und reproduzierbare Methode ist. Im zweiten Teil wurden qualitative und quantitative Unterschiede zwischen DNA von Brustkrebszellen und DNA von Leukozyten detektiert. Die dazu benutzten Primer basieren auf Sequenzen die in den Mechanismen der Tumorgenese involviert sind. Unsere Studie hat gezeigt, dass random priming in der Abschätzung von genomischen Schäden im Brustkrebs sehr nutzbar sein kann. / In the first part of this work, we have optimized random amplified polymorphic DNA (RAPD) for the use of human DNA in altering the concentration of the reaction components and the steps of the thermal profile in the polymerase chain reaction, by testing a large number of polymerases and multiple combinations with respect to their ability to increase the spectrum of amplimers and by examining the performance of various thermocyclers. We conclude that RAPD is a robust and reproducible method that could prove very useful for scientists and physicians. In the second part we used primers that were designed by choosing sequences involved in the development of DNA mutations, to successfully detect qualitative and quantitative differences between breast cancer DNA/normal DNA pairs. Our study showed that random priming proves very useful for assessing genomic damage in breast cancer.

Thesis (doctoral)--Lund University, 1998. / Includes bibliographical references.

Thesis (doctoral)--Lund University, 1998. / Includes bibliographical references.

The work described in this thesis is aimed at developing a novel piezoelectric cantilever energy harvesting circuit, so that more energy can be obtained from a particular piezoelectric harvester than is possible using conventional circuits. The main focus of the work was to design, build and test a proof of principle system, and not a commercial version, so as to determine any limitations to the circuit. The circuit functions by cancelling the capacitive output reactance of the piezoelectric harvester with a simulated inductance, and is based on an idea proposed by Qi in 2011. Although Qi's approach demonstrated that the circuit could function, the system proved too lossy, and so a less lossy version is attempted here. Experimental and software simulations are provided to verify the theoretical predictions. A prototype amplified inductor circuit was simulated and tested. From the simulation results, although harmonic current losses were found in the circuit, it was found that the circuit should produce an amplified effective inductance and a maximum output power of 165mW. The effective inductance is derived from the voltage across the 2H inductor, and this voltage is amplified and applied to the circuit via an inverter, to provide an extra simulated inductance, so that the overall inductance can be resonated with the piezoelectric harvester output capacitance. Hence the capacitive impedance of the harvester is nearly cancelled. The study and analysis of the amplified inductor circuit was carried out for a single cantilever harvester. Both open loop and closed loop testing of the system were carried out. The open loop test showed that the concept should function as predicted. The purpose of the closed loop test was to make the system automatically adjust for different resonance frequencies. The circuit was tested at 52Vpp inverter output voltage, and demonstrated a harvested power of 145.5mW. Experimental results show that the harvester output power is boosted from 8.8mW as per the manufacturer data sheet to 145.5mW (16.5 times). This is approximately double the power available using circuits described in the literature.

A música é vista principalmente como arte e lazer e também pode exercer um importante papel na educação de adolescentes, trazendo muitos benefícios. Ela não é apenas agradável para a audição, contribui para o bem estar físico e emocional, desencadeiam sensações que podem afetar o humor, a memória, a função cerebral (córtex pré-frontal, raciocínio), frequência cardíaca, metabolismo e sistema imunológico e percepção da dor. No entanto, além dos benefícios da música, quando o indivíduo se expõe de forma inadequada, o prazer proporcionado pode trazer efeitos desagradáveis para a saúde. A indústria da música amplificada, e principalmente a popularização dos dispositivos sonoros portáteis individuais é crescente entre os jovens, tornando a perda auditiva induzida por elevados níveis de pressão sonora entre crianças e adolescentes uma preocupação evidente. Os riscos, para adquirir a perda auditiva dependem de fatores como número de horas de uso dos fones auriculares ou intensidade. A quantidade de intensidade sonora bem como o tempo que se fica exposto a eles são fatores determinantes da capacidade de prejudicar a audição. Embora estes jovens estejam habituados à exposição à música elevada, não possuem conhecimento sobre os danos auditivos futuros que podem ser causados pela exposição, e quando apresentam esse conhecimento, não sabem exatamente como prevenir estes danos e proteger a sua audição. Dessa forma, o objetivo deste estudo foi: Investigar o nível de informação que os adolescentes têm sobre a música amplificada e a saúde auditiva bem como seus hábitos de escuta, investigar a prevalência de zumbido e alterações auditivas em adolescentes de ambos os sexos, e realizar revisão sistemática sobre os artigos relacionados ao tema. 59 adolescentes participaram deste estudo, responderam a um questionário sobre música amplificada e audição. O THI, foi realizado quando relataram zumbido. Realizaram meatoscopia, imitanciometria, audiometria tonal liminar e de alta frequência e logoaudiometria. Nos resultados, a pergunta formulada na revisão sistemática de literatura foi respondida e evidenciou que embora os jovens tenham uma informação prévia dos riscos da música amplificada e a audição, não é uma informação concreta e não demonstram vontade de mudar seus hábitos de escuta. Nos resultados do estudo clínico, embora não tenha sido encontrada perda auditiva, as curvas audiométricas sugeriram uma futura PAIM, e os questionários mostraram que os adolescentes tem uma informação prévia do assunto, ainda fazem o uso incorreto da música amplificada. Levando a concluir que campanhas efetivas e eficientes com informações completas devem ser feitas, de forma que atinja o interesse dos adolescentes e mude o seu comportamento frente à música amplificada, para que não se crie uma geração de jovens surdos. / The music is mainly seen as art and leisure and can bring many benefits on a teenagers education. It´s not just pleasant for hearing but contributes to the physical and emotional wellbeing, triggering feelings that can affect humor, memory, brain function (prefrontal cortex, reasoning) heart rate, metabolism, immunologic system and pain perception. However, besides of its benefits, when the person is improperly exposed to the music, the pleasure can bring unpleasant health effects. The amplified music industry and mainly by the popularization and by the rise of individual portable sound devices between the young people make the hearing loss, inducted by the exposure on high sound pressure level, an evident concern. The risks to acquire hearing loss are dependent on factors like the number of hours using the earphones and intensity. The quantity of sound intensity as well the period of exposure are determinant factors of the capacity to cause hearing harm. Although young people are accustomed to be exposed to high sound pressure level, they have no knowledge about the future harms that can be caused by exposure, and when they understand the risks, they not exactly know how to prevent those harms and how to protect their hearing. Thus, the objective of this study is to investigate the amount of information young people have about amplified music and hearing health as well to understand their hearing habits, investigate the prevalence of tinnitus and hearing changes on young people of both sexes and perform a systematic review of the studies regarding the theme. 59 teenagers have attended this study, answered a questionnaire about amplified music and hearing. The THI was executed for the subjects that reported tinnitus. They were submitted to meatoscopy, immittanciometry, tonal threshold and high frequency audiometry and logoaudiometry. The question raised during the review of the literature was answered by the results that showed that although young people have knowledge about the risks of amplified music and hearing, the information is not concrete and they show no desire to change their hearing habits. Although no hearing losses were detected, the results of the clinical studies, mainly by the audiometric curves, suggests future PAIM and the questionnaires revealed that the adolescents have prior information about the issue but even so, they still incorrectly use the amplified music which bring us to the conclusion that effectives and efficiency campaigns with complete information should be done to reach teenagers interests with the purpose to change their behavior regarding amplified music to avoid a future generation of deaf adolescents.

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