Rheological characterization of unmodified and chemically modified poly (ethylene terephthalate) resins

Intrinsic viscosity (IV) has often been misused for estimating both melt viscosity and elasticity of poly(ethylene terephthalate) (PET). A rheological study was conducted to determine the variations between a virgin unmodified PET and a recycled and chemically modified PET, both having a reported nominal IV of 0.95. The modified material had a larger melt viscosity (capillary and dynamic) than the virgin material (by an average of 61%). The extrudate swell, a better indicator of melt elasticity, of the modified was more than 110% greater than that of the unmodified material. Activation energies for melt viscosity and extrudate swell were found to be approximately 20 KJ/mol and 3 kJ/mol respectively, for the unmodified material at high shear rates. The melt viscosity for both materials was found to be best fitted by the Cross Model using a least-squares fit

Drell-Yan physics at COMPASS

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Polarized Drell-Yan studies at COMPASS

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La negación ilustrada en "Conducta entre marido y mujer" (1792)

El afán didáctico de la producción del XVIII, durante la Ilustración, acoge la producción ensayística que promueve la libertad de la mujer, arropada igualmente ésta bajo la luz orientadora de la educación y de la libertad igualadora frente a la posición del hombre. Al mismo tiempo arraigan abundantes textos que usan la defensa de la moral cristiana y sustentan la función que tradicionalmente correspondía a la mujer en el seno de la familia. Se inscribe en este panorama la obra “Conducta entre marido y mujer” de 1792. El trabajo analiza sus fuentes y estructura.The didactic character of the production of the 18th c. during the Enlightenment, welcomes essays that promote freedom of women, under the guiding light of education, freedom and equality before man’s position. At the same time many texts that use the defense of Christian morality and support the role that was traditionally assigned to women within the family structure begin to emerge. In this study we analyze the structure and source of the work "Conduct between husband and wife" (1792), the characteristics of which are an exponent of the second type of texts.peerReviewe

Asymptotic and numerical analysis of a simple model for blade coating

Motivated by the industrial process of blade coating, the two-dimensional flow of a thin film of Newtonian fluid on a horizontal substrate moving parallel to itself with constant speed under a fixed blade of finite length in which the flows upstream and downstream of the blade are coupled via the flow under the blade is analysed. A combination of asymptotic and numerical methods is used to investigate the number and nature of the steady solutions that exist. Specially, it is found that in the presence of gravity there is always at least one, and (depending on the parameter values) possibly as many as three, steady solutions, and that when multiple solutions occur they are identical under and downstream of the blade, but differ upstream of it. The stability of these solutions is investigated, and their asymptotic behaviour in the limits of large and small flux and weak and strong gravity effects, respectively, determined

Electrochemistry and STM-assisted Molecular electronics study of bimetallic hexaphyrins

ELECTROCHEMISTRY AND STM-ASSISTED MOLECULAR ELECTRONICS STUDY OF BIMETALLIC HEXAPHYRINS. The electron transport in porphyrinoids are related to several bioprocesses in Nature, from conversion from solar energy to chemical energy in photosynthesis to the transport and reduction of oxygen in aerobic animals. Due to these characteristics, several bioinspired applications have used this class of materials, photovoltaics, water splitting, catalysis and photodynamic therapy. To further understand how this process occurs in expanded porphyrins, 5 hexaphyrins in Hückel aromaticity were synthesized, with and without metal centres. These molecules were characterized by spectroscopy, electrochemistry and through molecular break junctions. The absorption spectrum of hexaphyrins show several possibly transitions, which splits and broadens with the addition of metal centres due to the degeneration of the molecule’s orbitals. The spectroscopic band gap was characterized by fluorimetry showing a gap between 1.12 to 1.20 eV for the molecules synthesized. Electrochemistry measurements shows several distinct quasi-reversible redox pairs. The addition of metal centres shifted the processes accordingly to the electronegativity of the metal centres. Due to the severe number of reactions a diagnosis criterium was developed to indicate which peaks corresponds to reactions in the macrocycle or its ligands and which are likely to occur on the metal centres. The molecular conductance of the hexaphyrins were studied with STM assisted break junctions on non-modified and modified gold as electrodes. The gold modification was proved necessary due to the lack of interactions between the molecules and the metal electrodes. Several current signatures were observed on 4-TPy modified gold. This corresponds to all possible molecular junction conformations. Upon the addition of metal centres, a similar trend is observed for each metal, indicating that the molecule properties do not impact as much as the conformation of the molecular wire.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)ELECTROCHEMISTRY AND STM-ASSISTED MOLECULAR ELECTRONICS STUDY OF BIMETALLIC HEXAPHYRINS. O transporte eletrônico em porfirinoides está relacionado com diversos bioprocessos na Natureza, da conversão de energia solar em energia química na fotossíntese ao transporte e redução de oxigênio em animais aeróbicos. Devido à essas características, diversas aplicações bioinspiradas utilizam essa classe de materiais, como fotovoltaicos, water splitting, catalisadores e terapia fotodinâmica. Para compreender como esses processos ocorrem em porfirinas expandidas, cinco hexafirinas foram sintetizadas em aromaticidade de Hückel, com e sem centros metálicos. Estas moléculas foram caracterizadas por técnicas espectroscópicas, eletroquímicas e por junções moleculares. Os espectros de absorção dessas hexafirinas mostram diversas transições possíveis, nas quais os desdobramento e alargamento das bandas com a adição de centros metálicos estão correlacionados com o a degeneração dos orbitais moleculares da molécula. O band gap espectroscópico foi caracterizado através de fluorimetria, elucidando um gap entre 1.12 e 1.20 eV. As medidas eletroquímicas mostram diversos processos quasi- reversíveis. A adição de centros metálicos desloca os potenciais dos processos redox de acordo com a eletronegatividade do metal adicionado. Devido ao grande numero de processos observados, um critério de diagnóstico foi desenvolvido para indicar quais processos ocorrem no centro metálico e quais processos ocorrem no macrociclo do material e seus ligantes. A condutância molecular das hexafirinas foram medidas através de junções moleculares assistidas por um STM, sob substratos de ouro. A funcionalização do ouro se mostrou necessária para observar os processos devido à falta de interações entre as moléculas e os eletrodos metálicos. Diversas “current signatures” foram observadas quando o ouro foi modificado com 4-TPy. Isto corresponde a cada possível conformação de junção molecular. Com a adição de centros metálicos, um comportamento similar pode ser observado de acordo com cada metal adicionado, indicando que as propriedades da molécula não influenciam a sua condutância tanto quanto a geometria do fio molecular.FAPESP: processo 2016/05363-

Will legume-insect specificity break down as the climate changes?

Granivores are among the most troublesome consumers of commercial crops, but they are also some of the best and most effective candidates for biological control agents of exotic and invasive plants. It is important to understand how they might behave in future climate conditions so that we can predict how they host range with change, how they might break out of their current specific niches, how their geographical extent might reach into new areas, and how their populations could be controlled by their natural enemies such as parasitoid wasps. This thesis is a valuable community-wide survey of plant-insect interactions, centered on the insect cohort of south-east Australian legumes, a family of plants that is commercially and ecologically important. By using a distance-for-time design across the elevation gradient of the Blue Mountains, this work has laid out the insects that can be found in the legumes of this region, their niches in the community, the different configurations the communities take under different climate conditions, and the different seasonal host use responses of weevils, wasps, and moths under those conditions. This thesis is an informative foothold for future researchers who want to use legumes to study community-level plant-insect associations, the processes that form them, and what makes them break down. The information shared herein provides new model inputs to improve future models of insect expansion and host choice, and suggestions of further work that might build on its findings and strengthen them. I hope that this work contributes to a generalised understanding of insects’ response to climate change

Matching of Mammographic Lesions in Different Breast Projections

De todos os cancros, cancro da mama é o que causa mais mortes entre mulheres. Programas de rastreio do cancro da mama podem ajudar a decrescer esta mortalidade, visto que deteção e tratamento do tumor em fases iniciais aumentam a taxa de sobrevivência. Normalmente, um par de radiologistas fazem a interpretação das mamografias, no entanto o processo é longo e cansativo. Isto incentivou o desenvolvimento de sistemas de diagnósitco auxiliado por computador (CADx), para substituir o segundo radiologista, fazendo melhor uso do tempo de especialistas. No entanto, sistemas CADx são associados a taxas elevadas de falsos positivos, dado que a maior parte detes apenas usam uma vista (craniocaudal ou mediolateral oblique) da mamografia. O radiologista, por sua vez, usa ambas as projeções, baseando o seu diagnóstico em diferenças visíveis entre as duas vistas. Quando se consideram as duas projeções da mamografia, a correspondência de lesões é um passo necessário para se fazer o diagnóstico. No entanto, isto é uma tarefa complexa, dado que podem existir vários candidatos a lesão, em cada uma das vistas, para se fazer correspondência. Neste trabalho, um sistema que faz correspondências entre lesões é proposto. Este é composto por três blocos: detetor de candidatos, extração de caraterísticas e correspondência de lesões. O primeiro é uma replicação do trabalho de Ribli et al., e o seu propósito é detetar possíveis candidatos a lesão. O segundo é a extração de vetores de caraterísticas de cada candidato, quer usando a backbone do detetor de candidatos, quer extraindo caraterísticas mais tradicionais, ou usando uma rede neuronal treinada com a triplet loss para distinguir lesões. O terceiro é o cálculo da distância entre os vetores de caraterísticas, usando também heurísticas para restringir possíveis pares de candidatos incorretos, e a ordenação de distâncias para atribuir a correspondência de cada lesão. Este trabalho oferece várias opções de possíveis extractores de caraterísticas e heurísticas a serem incroporados num sistema CADx que seja baseado em detetores de objetos. O facto do modelo treinado com a triplet loss ser competitivo com os restantos modelos, torna o sistema bastante mais viável, sendo que este oferece a possibilidade de a correspondência ser independente da deteção de candidatos. Heurísticas "hard" e "soft" são introduzidas como métodos para limitar correspondências. O sistema é capaz de fazer correspondências de forma satisfatória, dado que a sua exatidão ( 70%85%) é significativamente maior que a probabilidade aleatória (30%40%) dos dados usados. Heurísticas "hard" têm resultados encorajantes na precision@k, dado que estas rejeitam um número significativo de falsos positivos gerados pelo detetor de lesões.Of all cancer diseases, breast cancer is the most lethal among women. It has been shown that breast cancer screening programs can decrease mortality, since early detection increases the chances of survival. Usually, a pair of radiologists interpret the screening mammograms, however the process is long and exhausting. This has encouraged the development of computer aided diagnosis (CADx) systems to replace the second radiologist, making a better use of human-experts' time. But CADx systems are associated with high false positive rates, since most of them only use one view (craniocaudal or mediolateral oblique) of the screening mammogram. Radiologist, on the other hand, use both views; frequently reasoning about the diagnosis by noticeable differences between the two views. When considering both projections of a mammogram, lesion matching is a necessary step to perform diagnosis. However this is a complex task, since there might be various lesion candidates on both projections to match. In this work, a matching system is proposed. The system is a cascade of three blocks: candidates detector, feature extraction and lesion matching. The first is a replication of Ribli et al.'s Faster R-CNN and its purpose is to find possible lesion candidates. The second is the feature vector extraction of each candidate, either by using the candidates detector's backbone, handcrafted features or a siamese network model trained for distinguish lesions. The third is the calculus of the distance between feature vector, also using some heuristics to restrain possible non-lesion pairs, and the ranking of the distances to match the lesions. This work provides several options of possible feature extractors and heuristics to be incorporated into a CADx system based on object detectors. The fact that the triplet loss trained models obtained competitive results with the other features extractors is valuable, since it offers some independence between the detection and matching tasks. "Hard" heuristics and "soft" heurisitcs are introduced as methods to restrain matching. The system is able to detect matches satisfactorily, since its accuracy (70%85%) is significantly higher than chance level (30%40%). "Hard" heuristics proposals achieved encouraging results on precision@k, due to its match and candidates exclusion methods, which rejects a significant number of false positives generated by the object detector

Alcohol y toxicidad reproductiva

Los estudios epidemiológicos realizados en diferentes países, incluyendo Argentina, evidenciaron que el abuso del alcohol en la juventud y la adolescencia es un problema de interés y relevancia crecientes. En consecuencia, es de prever que el número de bebedores adultos se incremente en las próximas décadas. El efecto perjudicial del consumo de bebidas alcohólicas en la juventud es particularmente serio si se considera que en lo que concierne a la salud reproductiva, éste es el rango etario más comprometido en ambos sexos. La salud reproductiva de la mujer no es un tema menor teniendo en cuenta el aumento alarmante del consumo de bebidas alcohólicas en la edad relacionada directamente con la ventana de fertilidad. Es importante considerar que debido a las diferencias en el metabolismo del etanol, la mujer, en comparación con el hombre, se encuentra frente a un riesgo mayor de consecuencias negativas asociadas con el consumo de grandes cantidades de alcohol. Se han reportado consecuencias dañinas del abuso de alcohol en la mujer como por ejemplo, un riesgo significativo de infertilidad y un riesgo incrementado para la endometriosis. Otros trabajos concluyeron que la probabilidad de un embarazo exitoso disminuía con el aumento en el consumo de alcohol. Para el hombre, un gran número de estudios epidemiológicos demuestran que el consumo excesivo de alcohol se asocia con la alteración de la producción de testosterona y la atrofia testicular. Los desórdenes reproductivos provocados por el hábito de beber sin duda deben involucrar alteraciones de factores hormonales críticos para el control de las funciones reproductivas y también por la acción tóxica directa del etanol y sus metabolitos en los órganos que forman los sistemas reproductores de ambos sexos.Epidemiological studies conducted in different countries including Argentina showed that alcohol abuse in the youth and the adolescence is a problem of growing interest and relevance. Consequently, it can be envisaged that the number of adult drinkers will increase in the years to come. The detrimental effect of alcohol consumption on the health of young people is particularly serious when one considers that, with respect to reproductive health, this is the age range more engaged in both sexes. In women, reproductive health of women is not a minor issue considering the alarming increase in drinking at an age directly related to the fertility window. It is important to note that due to differences in the metabolism of ethanol, women, compared with men, are facing an increased risk of negative consequences associated with the consumption of large amounts of alcohol. Harmful consequences of alcohol abuse have been reported in women such as a significant risk of infertility and an increased risk for endometriosis. Other studies concluded that the probability of a successful pregnancy decreased with the increase in the consumption of alcohol. For men, a large number of epidemiological studies evidenced that excessive alcohol consumption is associated with impaired testosterone production and testicular atrophy. Reproductive disorders caused by drinking should certainly involve alterations in critical hormonal factors controlling reproductive functions but also due to the direct toxic action of ethanol and its metabolites in the organs that constitute the reproductive systems of both sexes.Fil: Quintans, Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Castro, Gerardo Daniel. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentin

Assignment, transgression and metaliterature in Roberto Bolaño´s "Killer Whores"

El trabajo analiza Putas asesinas de Roberto Bolaño. Se atiende a los principales rasgos narrativos y las temáticas esenciales desde tres bloques (adscripción, transgresión y metaliteratura) desde los que se concluye la presencia de varios ejes temáticos (sexualidad, muerte, violencia, literatura). Se plantean los fundamentos teóricos esenciales para el análisis narrativo. El mecanismo de análisis se sustenta en los presuepuesto teóricos de autores como Todorov, Genette o Bremond.The paper analyzes Roberto Bolaño´s Killer Whores. It serves the main features and key thematic narrative from three blocks (secondment, transgression and metaliterature) from which we conclude the presence of various themes (sexuality, death, violence, literature). This raises the theoretical foundations to the narrative analysis. The analysis mechanism is based on the theoretical ideas of authors such as Todorov, Genette and Bremond