Há atualmente um grande aumento na demanda por fontes de energia renováveis e de combustíveis que sejam menos poluentes, isto faz com que o etanol ganhe uma grande notoriedade como uma boa alternativa as fontes convencionais de energia. A tendência é de um grande aumento no consumo deste produto, para os próximos anos, o que vai exigir meios de transporte e estocagem seguros e eficientes, desde os produtores até os terminais de distribuição. Economicamente o melhor modo de transportar este produto é, sem nenhuma dúvida, através de dutos de aço, no entanto, existem estudos comprovando que alguns tipos de etanol são nocivos ao material empregado nos dutos. Dentre os modos de avaliar esta influência está a avaliação da tenacidade do material frente ao meio de interesse. Este trabalho tem por objetivo avaliar a tenacidade de um aço API 5L X70 quando exposto aos meios etanol de milho e etanol de cana, variando também o tempo de exposição do material no meio. Além disto, neste trabalho foram feitos diagramas FAD com os valores de tenacidade encontrados em escala reduzida para obter-se um indicativo da integridade estrutural do duto. Para tanto, foram preparados 10 corpos de prova do tipo C(T) entalhados e pré-trincados, respeitando a norma ASTM E647-08 e distribuídos da seguinte forma: 2 corpos de prova para ensaios ao ar, 4 corpos de prova para ensaios em meio etanol de cana e 4 corpos de prova para os ensaios em etanol de milho, além disto, foi utilizado o programa Vindio para a confecção dos diagramas FAD. Os resultados mostraram que os meios etanólicos de cana obtiveram resultados muito parecidos com os ensaiados ao ar, enquanto que no meio etanólico de milho fica evidenciada a fragilidade do material. Nas imagens fractográficas dos corpos de prova ensaiados foi confirmada a diferença na forma de fratura (frágil, no caso do etanol de milho e dúctil no etanol de cana e ao ar). / Nowadays, there is a large increase in the demand for renewable sources of energy and fuels more environment-friendly, this fact fortifies the ethanol’s image as a attractive alternative to conventional energy sources. The upward trend in the consumption of this product in the coming years will require safety and efficiently transportation and storage from producers to distribution terminals. Undoubtedly, the most economically way to transport this product is through pipelines, however, there are studies showing that some types of ethanol are damaging to the pipes material. One way to evaluate this harmful effect of ethanol is the toughness study of the material in the environment of interest. This study aims to assess the tenacity of the API 5L X70 steel when exposed to corn ethanol and sugarcane ethanol for different immersion times. Furthermore, to obtain an indication of the pipe’s structural integrity, FAD’s diagrams were plotted with toughness values determined in the small scale test. For this proposal, 10 C(T) specimens were notched and pre-cracked in accordance to the ASTM E647-08 and distributed as follows: 2 CPs for air test, 4 CPs for the sugarcane ethanol medium and 4 CPs for the corn ethanol. In addition, the Vindio software was used to make the FAD’s diagrams. The results showed that the tests realized in the air and in the sugarcane ethanol medium were very similar, while in the corn ethanol medium is evident the fragility of the material. The surface fracture confirmed the fragile behavior for specimen tested in the corn ethanol medium and ductile behavior for the sugarcane ethanol medium.

<p>The aims of this work were to image and analyze the needle behavior at automated core biopsy, to investigate the clinical utility of an alternative core biopsy technique using a semiautomated gun in breast and axillary lesions, and also to compare core biopsy with surgical specimens in malignant breast lesions regarding histologic features and hormone receptor expression.</p><p>In two experimental studies, using butter and silicon phantoms, respectively, the needle pass was imaged and its dynamic behavior studied. It was shown that the needle took a curved course in phantoms. It deviated to the same side as where the tip lay, and the degree of the curvature increased with increasing hardness of the phantoms. Our experimental methods can be applied for imaging of needle behavior and thereby improvement of needle configuration.</p><p>In two clinical studies, a semiautomated gun was used for large needle core biopsy of breast and axillary lesions in two series of 145 and 21 patients, respectively. The sensitivity of the method for diagnosis of malignancy was 87% (108/124), and in 37% (31/83) of cases the full length of the needle notch was filled with specimen. No injury to the neurovascular structures of the axillary area was observed. It was concluded that the semiautomated gun can be used as an alternative to the automated gun when the size and location of the lesion render use of the automatic device uncertain or dangerous, e.g., in small breast lesions or lesions located in the axilla.</p><p>In a series of 129 cases of breast cancer, comparison of core biopsy and surgical specimens showed that core biopsy provided enough information on the histologic type and grade of the lesions. Also, there was moderate to high concordance between the two methods for assessment of progesterone receptors and estrogen receptors (Spearman`s kappa 0.67 and 0.89, respectively).</p>

The aims of this work were to image and analyze the needle behavior at automated core biopsy, to investigate the clinical utility of an alternative core biopsy technique using a semiautomated gun in breast and axillary lesions, and also to compare core biopsy with surgical specimens in malignant breast lesions regarding histologic features and hormone receptor expression. In two experimental studies, using butter and silicon phantoms, respectively, the needle pass was imaged and its dynamic behavior studied. It was shown that the needle took a curved course in phantoms. It deviated to the same side as where the tip lay, and the degree of the curvature increased with increasing hardness of the phantoms. Our experimental methods can be applied for imaging of needle behavior and thereby improvement of needle configuration. In two clinical studies, a semiautomated gun was used for large needle core biopsy of breast and axillary lesions in two series of 145 and 21 patients, respectively. The sensitivity of the method for diagnosis of malignancy was 87% (108/124), and in 37% (31/83) of cases the full length of the needle notch was filled with specimen. No injury to the neurovascular structures of the axillary area was observed. It was concluded that the semiautomated gun can be used as an alternative to the automated gun when the size and location of the lesion render use of the automatic device uncertain or dangerous, e.g., in small breast lesions or lesions located in the axilla. In a series of 129 cases of breast cancer, comparison of core biopsy and surgical specimens showed that core biopsy provided enough information on the histologic type and grade of the lesions. Also, there was moderate to high concordance between the two methods for assessment of progesterone receptors and estrogen receptors (Spearman`s kappa 0.67 and 0.89, respectively).

Alkali Silica Reaction in concrete is a chemical deterioration process occurring between alkalis in cement paste and reactive aggregates. ASR increases expansion and cracking as well as other durability problems such as freezing and thawing. It is most probable that concrete structure will collapse unless mechanical, mineral, or chemical preventive measures are taken against ASR or this problem is realized and solved in the design stage of the concrete structure or later on. Rather than ordinary preventive measures in which mineral admixtures are used, mechanical ones were investigated in this study. In the experiment done by using the accelerated mortar bar method, reinforced concrete specimens on which pre-stressing force was applied were examined. The effects of reinforcement ratio and pre-stressing force on ASR based expansion and cracking were studied. Expansion and cracking developments in time were followed, and the connection between these phenomena and the energy produced by ASR was made. By applying the same mechanical preventive measures on the specimens prepared by using different reactive aggregates, the effectiveness of these methods with respect to the degree of v ASR was investigated. Also, the methods in question were compared with traditional preventive measures (fly ash). The investigation results show that reinforcement and pre-stressing force play a significant role in diminishing the effects of ASR.Keywords:Alkali-Silica Reaction, Reinforced Concrete Specimen, Pre-stressed Concrete, Mechanical Preventive Measures, Energy of ASR

Flattened Brazilian disc and modified ring test methods are attractive methods being simpler compared to the other mode I fracture toughness testing methods on rock cores. The aim of this study is to improve these simple methods to yield fracture toughness values that are close to the ones determined by the suggested methods. ABAQUS finite element program was used to determine stress intensity factors of models with various dimensions. Comparing fracture toughness to the results obtained by semicircular bending method tests (0.94 MPa&amp / #8730 / m for andesite and 0.56 MPa&amp / #8730 / m for marble) and the cracked chevron notched Brazilian disc method tests (1.45 MPa&amp / #8730 / m for andesite and 1.08 MPa&amp / #8730 / m for marble), proper geometrical parameters were investigated by changing diameter, central-hole diameter, and loading angle of Ankara andesite and Afyon marble specimens. Semicircular bending method results were lower than the cracked chevron notched Brazilian disc method results. With flattened Brazilian disc method, the closest results (1.45 MPa&amp / #8730 / m for andesite and 1.12 MPa&amp / #8730 / m for marble) to the suggested method was obtained by 54 mm diameter discs with loading angles between 32.5&deg / and 38.0&deg / and with thicknesses between 19 mm and 34 mm. With modified ring test on andesite, the closest results to the suggested method was obtained by 75 mm diameter discs with 8 mm central-hole diameter and 25&deg / loading angle (1.47 MPa&amp / #8730 / m for andesite and 1.07 MPa&amp / #8730 / m for marble), and with 14 mm central-hole diameter and 16&deg / loading angle (1.50 MPa&amp / #8730 / m for andesite and 1.05 MPa&amp / #8730 / m for marble).

In this study, low temperature cracking of asphalt concrete is investigated based on a laboratory experimental program including the design variables of aggregate type, gradation, asphalt content, binder grading, binder modification, and the experimental variables of cooling rate, and specimen size. The design of experiment is proposed according to the fractional factorial design principles to reduce the required number of test specimens. Mix designs are performed according to the Superpave mix design guidelines using materials obtained from the Turkish General Directorate of High-ways. In the course of this study, a test setup for thermal stress restrained specimen test for asphalt concrete is developed and used successfully to test a number of as-phalt concrete beam specimens. The same setup is also used for measuring the glass transition temperatures to obtain various thermo-volumetric properties of mixtures. Statistical methods are used to identify the effect of experimental variables on frac-ture strength, fracture temperature and other dependent variables obtained from the testing program. Statistical models are also developed to predict the fracture strength, fracture temperature and other thermo-volumetric properties of mixtures. Results of analyses show that aggregate type, binder modification, and asphalt content significantly affect both the fracture strength and fracture temperature of asphalt concrete. While the glass transition temperature is affected by only aggregate type, coefficients of contraction before and after the glass transition temperature are not influenced by any of the experimental variables. The results of this study provide an important basis to prevent low temperature cracking in asphalt concrete pavements.

The paper presents results of a research project founded by the Swiss Federal Nuclear Inspectorate concerning the application of the Master Curve approach in nuclear reactor pressure vessels integrity assessment. The main focus is put on the applicability of pre-cracked 0.4T-SE(B) specimens with short cracks, the verification of transferability of MC reference temperatures T0 from 0.4T thick specimens to larger specimens, ascertaining the influence of the specimen type and the test temperature on T0, investigation of the applicability of specimens with electroerosive notches for the fracture toughness testing, and the quantification of the loading rate and specimen type on T0. The test material is a forged ring of steel 22 NiMoCr 3 7 of the uncommissioned German pressurized water reactor Biblis C. SE(B) specimens with different overall sizes (specimen thickness B=0.4T, 0.8T, 1.6T, 3T, fatigue pre-cracked to a/W=0.5 and 20% side-grooved) have comparable T0. T0 varies within the 1σ scatter band. The testing of C(T) specimens results in higher T0 compared to SE(B) specimens. It can be stated that except for the lowest test temperature allowed by ASTM E1921-09a, the T0 values evaluated with specimens tested at different test temperatures are consistent. The testing in the temperature range of T0 ± 20 K is recommended because it gave the highest accuracy. Specimens with a/W=0.3 and a/W=0.5 crack length ratios yield comparable T0. The T0 of EDM notched specimens lie 41 K up to 54 K below the T0 of fatigue pre-cracked specimens. A significant influence of the loading rate on the MC T0 was observed. The HSK AN 425 test procedure is a suitable method to evaluate dynamic MC tests. The reference temperature T0 is eligible to define a reference temperature RTTo for the ASME-KIC reference curve as recommended in the ASME Code Case N-629. An additional margin has to be defined for the specific type of transient to be considered in the RPV integrity assessment. This margin also takes into account the level of available information of the RPV to be assessed.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009. / Härtill 6 uppsatser.

Pandemic outbreaks are unpredictable as to their virus strain, transmissibility, and impact on our quality of life. Hence, the decision support models for mitigation of pandemic outbreaks must be user-friendly and operational, and also incorporate valid estimates of disease transmissibility and severity. This dissertation research is aimed at 1) reviewing the existing pandemic simulation models to identify their implementation gaps with regard to usability and operability, and suggesting research remedies, 2) increasing operability of simulation models by calibrating them via an epidemiological model that estimates infection probabilities using viral shedding profiles of concurrent pandemic and seasonal influenza, and 3) developing a testing strategy for the state laboratories, with their limited capacities, to improve their ability to estimate evolving transmissibility parameters. Our review of literature (Aim 1) indicates the need to continue model enhancements in critical areas including updating of epidemiological data during a pandemic, smooth handling of large demographical databases, incorporation of a broader spectrum of social-behavioral aspects, and improvement of computational efficiency and accessibility. As regards the ease of calibration (Aim 2), we demonstrate that the simulation models, when driven by the infection probabilities obtained from our epidemiological model, accurately reproduce the disease transmissibility parameters. Assuming the availability of sufficient disease reporting infrastructure and strong compliance by both infected population and healthcare providers, our testing strategy (Aim 3) adequately supports characterization of real-time epidemiological parameters. Future research on this topic will be aimed at integrating the laboratory testing strategy with our modeling and simulation approach to develop dynamic mitigation strategies for pandemic outbreaks.

Being able to extrapolate interaction values from a database of pullout resistance testing results may possibly help with narrowing down the most suitable reinforcement/fill material combinations for a Mechanically Stabilized Earth wall, thereby reducing the number of tests needed for a design and maximizing the efficiency of the system. The objectives of this thesis include the following: collect and organize a broad collection of data in a way that can assist in preliminary selection of interaction properties for uniaxial geogrids; analyze the collection of data for trends related to geogrid polymer type; analyze the collection of data for trends related to the presence of fines in the fill material; compare the collected data to previous studies on the effects of geogrid specimen length on pullout performance; and compare the collected data to previous studies on the effect of geogrid rib thickness to mean particle size ratio on normalized bearing stress and CI values. The data from 101 pullout tests are presented in tabular and graphic form so that the coefficient of interaction may be interpolated for many geogrid/fill material combinations. The effect of polymer type (PET vs HDPE) was shown to have little effect on how a geogrid performs in a fill material. In one case, the two polymer types exhibit differing trends within the same fill material. The presence of fines (>12% by weight) in the fill material results in a significant decrease in the coefficient of interaction when compared to clean granular fills. The effects of geogrid embedment length have significant effects on the results of geogrid pullout tests. Samples with shorter lengths were shown to carry a greater load per unit area than longer samples. Normalized bearing stress is shown to be heavily influenced by the geogrid transverse rib thickness to mean particle size ratio (B/D50). For a particular fill material, normalized bearing stress decreases linearly with increasing B/D50. For a particular geogrid, normalized bearing stress is shown to have a bi-linear behavior with increasing B/D50. Initially, normalized bearing stress increases with increasing B/D50. After reaching a peak, normalized bearing stress begins to decrease with increasing B/D50. / text