Chip seals are a commonly used surface treatment used to decrease the deterioration rate of pavement surfaces. Chip seals typically consist of an application of emulsion and cover aggregate. Failure can be driven by improper strength development and inadequate bonding over time. Additionally, chip seal service life varies and long term performance prediction models are not well established. This study has two primary goals. The first goal is to investigate aggregate retention characteristics of chip seal specimens, while investigating material compatibility by means of the Sweep-M test. The second goal is to begin developing a long term performance (LTP) test to represent cores obtained from full-scale chip seal projects. Conditioning and testing protocols for LTP specimens are evaluated for representative chip seal behavior over long periods. Results confirm material interaction and favor the incorporation of sweep testing for optimum performance. Future testing is recommended for in-depth, LTP test protocol evaluation.

The structured winds of single massive stars can be classified into two broad groups: stochastic structure and organized structure. While the former is typically identified with clumping, the latter is typically associated with rotational modulations, particularly the paradigm of corotating interaction regions (CIRs). While CIRs have been explored extensively in the ultraviolet band, and moderately in the X-ray and optical, here we evaluate radio variability from CIR structures assuming free-free opacity in a dense wind. Our goal is to conduct a broad parameter study to assess the observational feasibility, and to this end, we adopt a phenomenological model for a CIR that threads an otherwise spherical wind. We find that under reasonable assumptions, it is possible to obtain radio variability at the 10 per cent level. The detailed structure of the folded light curve depends not only on the curvature of the CIR, the density contrast of the CIR relative to the wind, and viewing inclination, but also on wavelength. Comparing light curves at different wavelengths, we find that the amplitude can change, that there can be phase shifts in the waveform, and the entire waveform itself can change. These characterstics could be exploited to detect the presence of CIRs in dense, hot winds.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24420号 / 理博第4919号 / 新制||理||1703(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 前田 啓一, 講師 LEE Shiu Hang, 教授 太田 耕司 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

The characterization of flammability parameters such as time to ignition, mass loss rate (MLR), and extinction criteria is critical for understanding ignition and burning behavior of timber products. These parameters, often determined with bench scale experiments, have previously been presented in literature. However, standard test methods generally use relatively low trial quantities (e.g., n=3) which can potentially cause large variation in reported values. This study investigates the influence of trial quantity on observed statistical variation in key flammability metrics for timber products (e.g., ignition time, peak MLR, MLR at extinction). Using a conical heater, 100 repeat trials were conducted at incident heat exposures of 20 kW/m2, 40 kW/m2, and 50 kW/m2 on 12.7 mm thick ACX cross laminated plywood samples. Ignition time data was found to exhibit significant positive skew and 20-30 trials were required for the reduction in uncertainty with each additional trial to fall below 0.1s at each heat flux. The normalized uncertainty in ignition time was greatest at 50 kW/m2 and was 20-70% than at 20 kW/m2 and 40 kW/m2. Significant variability was observed in the extinction characteristics of samples exposed to 40 kW/m2 where 39 samples experienced self-extinction while the remainder sustained combustion until burnout. Uncertainty in MLR at extinction for these trials was nearly double that of trials exposed to 20 kW/m2. These results exhibit the significance of large trial quantities when determining flammability characteristics.

"This dissertation documents two interrelated studies that were conducted to more fundamentally understand the scalability of flame heat flux. The first study used an applied heat flux in the bench scale horizontal orientation which simulates a large scale flame heat flux. The second study used enhanced ambient oxygen to actually increase the bench scale flame heat flux itself. Understanding the scalability of flame heat flux more fully will allow better ignition and combustion models to be developed as well as improved test methods. The key aspect of the first study was the use of real scale applied heat flux up to 200 kW/m2. An unexpected non-linear trend is observed in the typical plotting methods currently used in fire protection engineering for ignition and mass loss flux data for several materials tested. This non-linearity is a true material response. This study shows that viewing ignition as an inert material process is inaccurate at predicting the surface temperature at higher heat fluxes and suggests that decomposition kinetics at the surface and possibly even in-depth may need to be included in an analysis of the process of ignition. This study also shows that viewing burning strictly as a surface process where the decomposition kinetics is lumped into the heat of gasification may be inaccurate and the energy balance is too simplified to represent the physics occurring. The key aspect of the second study was direct experimental measurements of flame heat flux back to the burning surface for 20.9 to 40 % ambient oxygen concentrations. The total flame heat flux in enhanced ambient oxygen does not simulate large scale flame heat flux in the horizontal orientation. The vertical orientation shows that enhanced ambient oxygen increases the flame heat flux more significantly and also increases the measured flame spread velocity."

Made available in DSpace on 2017-07-24T19:22:05Z (GMT). No. of bitstreams: 1 MANOELA HASS DOLINSKI THOMASSEWSKI.pdf: 1885236 bytes, checksum: f6df4dd8ee0fdb0bea20dba5b9c53058 (MD5) Previous issue date: 2008-02-26 / The purpose of this study was to measure mass loss and surface roughness (Ra) changes of differents glass ionomer cement indicated to atraumatic restorative treatment, with a resin composite used as control material, after a simulated toothbrushing test. The surface characteristics before and after abrasion were evaluated on scanning electron microscopy (SEM). The tested materials were: Vitro Fil LC® ,Fuji IX® , Vitro Molar® , Maxxion R®, and the resin composite Filtek Z100®. Ten samples (6mm in diameter and 5mm thick) on all samples from each were prepared according to manufacturers’ instructions. Toothbrushing abrasion was performed on all specimens from each of the materials using a simulator. The mass loss, surface roughness and qualitative analyse were assessed before and after 20000 brushstrokes, using Shimadzu analytical balance of 0,0001g accuracy, a Mitutoyo surftest-301 and Shimadzu SSX-550 Superscan respectively. The measurements of both properties were statiscally compared by Anova one-way and then paired t-test and Tukey’s test. Correlation between mass loss and surface roughness was calculated. The level significance was α=5% (p<0,05). All materials presented a statistically significant mass loss comparing initial and final values. The loss mass in order decreasing was Vitro Fil LC>Maxxion R> Vitro Molar>Filtek Z100>Fuji IX. All materials became rougher with the exception of Vitro Molar that presented low roughness after toothbrushing test. There was no correlation between wear and surface roughness and SEM observations were in accordance to those roughness measured. In conclusion, the findings of this study showed that, the high viscosity glass cement ionomer presented wear and roughness seems to control material and the fluoride release propertie, this may be adequate for atraumatic restorative treatment. However, long-term clinical evaluation are necessary to better indicate this category of materials / O objetivo deste estudo foi mensurar a perda de massa e as alterações de rugosidade média superficial (Ra) de diferentes cimentos de ionômero de vidro indicados para tratamento restaurador atraumático tendo uma resina composta como material controle, após teste de escovação simulada. As características de superfície antes e após abrasão foram avaliadas em microscópio eletrônico de varredura (MEV). Os materiais testados foram: Vitro Fil LC® ,Fuji IX® , Vitro Molar® , Maxxion R®, e a resina composta microhíbrida Filtek Z100®. Dez amostras (6mm de diâmetro e 5mm de espessura) de cada material foram confeccionados de acordo com as instruções do fabricante. O teste foi conduzido em uma máquina de escovação simulada, em todas as amostras de todos os materiais, totalizando 20000 ciclos. Antes e após o teste, a massa, rugosidade e analise qualitativa em MEV, de cada material foram aferidas em um balança analítica Shimadzu de 0,0001g de precisão, pelo equipamento Mitutoyo modelo surftest-301 e pelo microscópio Shimadzu SSX-550 Superscan., respectivamente. Os resultados das variáveis perda de massa e rugosidade foram analisados pelo teste ANOVA de um critério e então o pós-teste para comparações múltiplas de Tukey, com o objetivo de identificar entre quais grupos situavam as diferenças. Para analisar a relação entre perda de massa e rugosidade média foi utilizada a análise de regressão linear. O nível de significância empregado foi de α=5% (p<0,05), utilizado para todas as análises. Todos os materiais apresentaram diferenças estatísticas de perda de massa entre valores iniciais e finais. A perda de massa em ordem decrescente foi Vitro Fil LC>Maxxion R> Vitro Molar>Filtek Z100>Fuji IX. Os materiais se tornaram mais rugosos exceto o Vitro Molar que apresentou menor rugosidade após teste. Não houve correlação entre perda de massa e rugosidade superficial. Observações ao MEV estavam de acordo com as medidas de rugosidade. Concluindo, os achados deste estudo mostraram que os cimentos de alta viscosidade apresentaram desgaste e rugosidade semelhantes ao material controle e ainda possuem a propriedade de liberar flúor, sendo adequado para tratamento restaurador atraumático. Entretanto, avaliações clínicas são necessárias para melhor indicar esta categoria de material.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-19T15:05:15Z No. of bitstreams: 2 Tese - Lismaíra Gonçalves Caixeta Garcia - 2017.pdf: 2339192 bytes, checksum: 8eafbf8b875a28ace87e8f4ccc8608eb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-19T15:23:16Z (GMT) No. of bitstreams: 2 Tese - Lismaíra Gonçalves Caixeta Garcia - 2017.pdf: 2339192 bytes, checksum: 8eafbf8b875a28ace87e8f4ccc8608eb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-19T15:23:16Z (GMT). No. of bitstreams: 2 Tese - Lismaíra Gonçalves Caixeta Garcia - 2017.pdf: 2339192 bytes, checksum: 8eafbf8b875a28ace87e8f4ccc8608eb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-06-30 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Jabuticaba fruit is known and appreciated all over the world. Despite its recognized functional properties, it has a limited market due to its high perishability. The present study aimed to evaluate the physicochemical characterization of jabuticaba fruits variety Pingo de mel during its physiological development, and the effect of different calcium chloride concentrations on the post-harvest conservation of jabuticaba at different storage temperatures. To evaluate the physiological development, the fruits were collected ten days after the anthesis (DAA) until complete maturation, with intervals of four days between the collections. The period between anthesis and maturation was 34 days. For the post-harvest analysis, the fruits were collected 30 days after the anthesis and immersed into calcium chloride solution at different concentrations (0%, 2%, 4%, and 6%) for 30 minutes at room temperature. Then, the fruits were dried and packed in polypropylene bags and stored at different temperatures (6°C, 12°C, and 25°C). Samples were analyzed at time 0 and every two days, up to 12 days of storage. In the physiological development, the mean diameter, mass, soluble solids, and anthocyanins content increased up to 30 DAA, while the soluble pectin increased up to 34 DAA. A reduction in respiratory rate was observed up to 30 DAA, as well as the firmness and total chlorophyll indices up to 34 DAA, and pH up to 18 DAA, which increased up to 34 DAA. In contrast, an opposite behavior was observed for acidity values. Higher levels of phenolic compounds, hydrolyzed tannins, and antioxidant activity were observed at 10 DAA, while the vitamin C content was higher throughout the maturation stage. An increase in moisture, protein, and lipids was observed up to 18 DAA, with reduction until maturation, with opposite behavior for ash and carbohydrates levels. In general, minerals decreased throughout the development stage. In relation to the carbohydrate profile, higher fructose contents were observed with an increase during maturation. In the post-harvest evaluation, the different calcium chloride concentrations had no effect on the maintenance of fruit characteristics over time, at different storage temperatures. Throughout the storage, there was an increase in pectin, antioxidant activity, CO2, total sugars, acidity, and mass loss. Higher storage temperatures affected both the increase in mass loss, pH, and O2 production, and the reduction of vitamin C content Therefore, to obtain better quality fruits concerning the degree of maturation, it is of great importance to harvest jabuticaba between 30 and 34 DAA. Refrigeration was important for the post-harvest conservation of the jabuticaba fruits variety Pingo de mel, once the fruits stored at 6 ° C suffered minor variations, with improvements or little changes during the 12 days. / A jabuticaba é um fruto conhecido e apreciado em praticamente todo o mundo, além disso, possui alegadas propriedades funcionais. No entanto o fruto apresenta comércio limitado, devido a sua alta perecibilidade. Objetivou-se com o presente trabalho caracterizar física e quimicamente os frutos de jabuticaba variedade ‘Pingo de mel’ ao longo do seu desenvolvimento fisiológico, bem como analisar a influencia da aplicação de diferentes concentrações de cloreto de cálcio, associado a diferentes temperaturas de armazenamento na conservação pós-colheita de jabuticaba. Para a caracterização do desenvolvimento fisiológico, os frutos foram coletados aos dez dias após a antese (DAA) e prorrogou-se até o completo amadurecimento, com intervalos de quatro dias entre as coletas. O período compreendido entre a antese e o amadurecimento foi de 34 dias. Para a análise pós-colheita os frutos foram coletados aos trinta dias após a antese e submetidos à imersão em solução de cloreto de cálcio, com diferentes concentrações (0%, 2%, 4% e 6%), durante 30 minutos, à temperatura ambiente. Posteriormente, foram secas e embaladas em potes de polipropileno e armazenadas em diferentes temperaturas (6°C, 12°C e 25°C). As amostras foram analisadas no tempo 0 e a cada dois dias, até os 12 dias de armazenamento. No desenvolvimento fisiológico observou-se que os valores de diâmetros, massa e sólidos solúveis e antocianinas, aumentaram até os 30 DAA, enquanto que os teores de pectina solúvel elevaram-se até os 34 DAA. A taxa respiratória apresentou resultado oposto com redução até os 30 DAA, os teores de firmeza e clorofila total apresentaram redução até os 34 DAA, o pH reduziu até os 18 DAA, com posterior elevação até os 34 DAA, enquanto que a acidez apresentou comportamento contrário. Níveis elevados de compostos fenólicos, taninos hidrolisados e atividade antioxidante foram observados aos 10 DAA, enquanto o conteúdo de vitamina C foi maior ao longo do amadurecimento. Observou-se aumento na umidade, proteína e lipídios até 18 DAA, com redução até a maturação, e notou-se comportamento oposto para os níveis de cinzas e carboidratos. Em geral, os minerais diminuíram ao longo do desenvolvimento. Em relação ao perfil de carboidratos, a frutose apresentou maior concentração, com aumento durante a maturação. Na análise pós-colheita as diferentes concentrações de cloreto de cálcio não apresentaram efeito na conservação das características dos frutos nas diferentes temperaturas de armazenamento e nem mesmo ao longo do tempo. No decorrer dos dias de armazenamento houve aumento dos teores de pectinas, da atividade antioxidante, do CO2, dos açúcares totais, da acidez e da perda de massa. Maiores temperaturas influenciaram no aumento da perda de massa, do pH e da produção de O2 e redução da vitamina C. Portanto para se obter frutos de melhor qualidade em relação ao grau de maturação é de grande importância realizar a colheita entre 30 e 34 DAA. Na pós-colheita a refrigeração foi importante para a conservação pós-colheita dos frutos de jabuticaba variedade ‘Pingo de mel’, visto que as frutas submetidas à temperatura de 6°C de armazenamento sofreram menores variações e/ou mantiveram condições semelhantes ou melhores nos frutos durante os 12 dias.

The Chandra and XMM-Newton X-ray telescopes have led to numerous advances in the study and understanding of astrophysical X-ray sources. Particularly important has been the much increased spectral resolution of modern X-ray instrumentation. Wind-broadened emission lines have been spectroscopically resolved for many massive stars. This contribution reviews approaches to the modeling of X-ray emission line profile shapes from single stars, including smooth winds, winds with clumping, optically thin versus thick lines, and the effect of a radius-dependent photoabsorption coefficient.

Theoretical models predict that the compressed interstellar medium around runaway O stars can produce high-energy non-thermal diffuse emission, in particular, non-thermal X-ray and γ-ray emission. So far, detection of non-thermal X-ray emission was claimed for only one runaway star, AE Aur. We present a search for non-thermal diffuse X-ray emission from bow shocks using archived XMM-Newton observations for a clean sample of six well-determined runaway O stars. We find that none of these objects present diffuse X-ray emission associated with their bow shocks, similarly to previous X-ray studies toward ζ Oph and BD+43°3654. We carefully investigated multi-wavelength observations of AE Aur and could not confirm previous findings of non-thermal X-rays. We conclude that so far there is no clear evidence of non-thermal extended emission in bow shocks around runaway O stars.

The β Cephei stars represent an important class of massive star pulsators that probe the evolution of B-type stars and the transition from main sequence to hydrogen-shell burning evolution. By understanding β Cep stars, we gain insights into the detailed physics of massive star evolution, including rotational mixing, convective core overshooting, magnetic fields, and stellar winds, all of which play important roles. Similarly, modeling their pulsation provides additional information into their interior structures. Furthermore, measurements of the rate of change of pulsation period offer a direct measure of β Cephei stellar evolution. In this work, we compute state-of-the-art stellar evolution models assuming different amounts of initial rotation and convective core overshoot and measure the theoretical rates of period change, that we compare to rates previously measured for a sample of β Cephei stars. The results of this comparison are mixed. For three stars, the rates are too low to infer any information from stellar evolution models, whereas for three other stars the rates are too high. We infer stellar parameters, such as mass and age, for two β Cephei stars: ξ1 CMa and δ Cet, which agree well with independent measurements. We explore ideas for why models may not predict the higher rates of period change. In particular, period drifts in β Cep stars can artificially lead to overestimated rates of secular period change.