Modelling desiccation cracking in a homogenous soil clay layer: comparison between different hypotheses on constitutive behaviour

Desiccation cracks are usually thought to start from the surface of an evaporating soil layer, and the available simplified models for crack initiation and propagation are based on this hypothesis. On the contrary, experimental results on a Dutch river clay showed that cracks in an evaporating soil layer may start and propagate below the surface, confirming earlier findings by other researchers. A simple one-dimensional model was set up to analyse the consequences of different hypotheses about the material behaviour on the crack onset in a homogenous soil layer undergoing surface drying. The results of the model show that dependence of the material behaviour on the rate of water content change is a necessary requirement for cracks to initiate below the surface. The conclusion suggests that, to properly understand cracking in an evaporating soil layer, an intrinsic time scale for the mechanical response must be accounted for, among all the other factors which were previously highlighted by other researchers. The key factor to predict crack onset below the surface is the dependence of the drying branch of the water retention curve of the compressible soil on the rate of drying, which would be justified by a rate dependent fabric evolution

Herança de formato e produção de frutos imaturos em abobrinha (Cucurbita moschata)

Two inbred lines of C. moschata were crossed to obtain Fl, F2 and F1BC1 for both parental generations to study the inheritance of immature fruit shape and production. Four replications for each generation were choosen in a randomized block design. For each one of the eleven harvestings, the following parameters were evaluated: weight, length and diameter near peduncle and style ends of the immature fruits. Through the results it is concluded that there is dominance for higher growth speed of the fruits, which determines greater length, diameters and weight, when they were harvested at the same age, and, therefore, greater yield per plant.O objetivo deste trabalho foi determinar a herança de formato e produção de frutos imaturos de 2 novas linhagens de C. moschata. Para tal obtiveram-se as gerações Fl, F2 e retrocruzamentos para ambos os progenitores. Para a avaliação das diferentes gerações utilizou-se o delineamento em blocos ao acaso com 4 repetições e número variável de plantas por repetição. As estimativas dos parâmetros genéticos foram obtidas segundo o modelo de MATHER & JINKS. Foram avaliados o peso, comprimento e diâmetros próximos das extremidades peduncular e estilar dos frutos. Observou-se dominância para maior velocidade de crescimento dos frutos, caracterizada pelos maiores comprimentos, diâmetros e peso médio na geração F1. Observou-se também dominancia para frutos mais bojudos e com menor relação entre o comprimento e a média dos diâmetros. Devido ao maior peso médio de frutos, e não ao número, obteve-se heterose significativa (20,5%) para produção total por planta

Methodological enhancements in MDO process investigated in the AGILE European project

This paper presents methodological investigations performed in research activities in the field of MDO in overall aircraft design in the ongoing EU funded research project AGILE. AGILE is developing the next generation of aircraft Multidisciplinary Design and Optimization processes, which target significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and describes the achievements of the 1st year (Design Campaign 1) leading to a reference distributed MDO system. A focus is then made on the different novel optimization techniques studied during the 2nd year, all willing to ease the optimization of complex work flows, characterized by high degree of discipline interdependencies, high number of design variables in the context of multi-level and multi-partner collaborative engineering projects. Then the implementation of these methods in the enhanced MDO framework is discussed

Lifestyle Modifications to Help Prevent Headache at a Developmental Age

Headache is the world's seventh most significant cause of disability-adjusted-life in people aged between 10 and 14 years. Therapeutic management is based on pharmacological approaches and lifestyle recommendations. Many studies show associations between each migraine-promoting lifestyle, behavioral triggers, frequency, and intensity of headaches. Nevertheless, the overall aspects of this topic lack any definitive evidence. Educational programs advise that pediatric patients who suffer from migraines follow a correct lifestyle and that this is of the utmost importance in childhood, as it will improve quality of life and assist adult patients in avoiding headache chronicity, increasing general well-being. These data are important due to the scarcity of scientific evidence on drug therapy for prophylaxis during the developmental age. The "lifestyle recommendations" described in the literature include a perfect balance between regular sleep and meal, adequate hydration, limited consumption of caffeine, tobacco, and alcohol, regular physical activity to avoid being overweight as well as any other elements causing stress. The ketogenic diet is a possible new therapeutic strategy for the control of headache in adults, however, the possible role of dietary factors requires more specific studies among children and adolescents. Educational programs advise that the improvement of lifestyle as a central element in the management of pediatric headache will be of particular importance in the future to improve the quality of life of these patients and reduce the severity of cephalalgic episodes and increase their well-being in adulthood. The present review highlights how changes in different aspects of daily life may determine significant improvements in the management of headaches in people of developmental age

Prevalence and severity of airway obstruction in an Italian adult population

Background. This study sets out to estimate the prevalence and the degree of severity of bronchial obstruction in an adult population with three different diagnostic criteria: the European Respiratory Society (ERS), the American Thoracic Society (ATS), and the World Health Organization (WHO) defined as Global Obstructive Lung Disease (GOLD). Methods. 1514 subjects underwent complete medical evaluation and spirometry. Results. The prevalence of bronchial obstruction was respectively 27.5% (ERS), 33% (GOLD), and 47.3% (ATS). The prevalence of bronchial obstruction in the smoker group was 33.4% (ERS), 38.1% (GOLD), and 52.3% (ATS). The prevalence of obstruction in the ex-smoker group was 33% (ERS), 41.4% (GOLD), and 57.1% (ATS). The prevalence of obstruction in the non-smoker group was 21.1% (ERS), 24.9% (GOLD), and 38.6% (ATS). Conclusions. The results show that the prevalence of airway obstruction increases proportionally with age; the cigarette smoking represents an important conditioning factor. These observations warrant the necessity of a more complete and multi-parametric analysis in the evaluation of patients with airway obstruction using methodologies that explore the functional state and the risk factors that cause the airway obstruction

Prevalence and severity of airway obstruction in an Italian adult population

Background. This study sets out to estimate the prevalence and the degree of severity of bronchial obstruction in an adult population with three different diagnostic criteria: the European Respiratory Society (ERS), the American Thoracic Society (ATS), and the World Health Organization (WHO) defined as Global Obstructive Lung Disease (GOLD). Methods. 1514 subjects underwent complete medical evaluation and spirometry. Results. The prevalence of bronchial obstruction was respectively 27.5% (ERS), 33% (GOLD), and 47.3% (ATS). The prevalence of bronchial obstruction in the smoker group was 33.4% (ERS), 38.1% (GOLD), and 52.3% (ATS). The prevalence of obstruction in the ex-smoker group was 33% (ERS), 41.4% (GOLD), and 57.1% (ATS). The prevalence of obstruction in the non-smoker group was 21.1% (ERS), 24.9% (GOLD), and 38.6% (ATS). Conclusions. The results show that the prevalence of airway obstruction increases proportionally with age; the cigarette smoking represents an important conditioning factor. These observations warrant the necessity of a more complete and multi-parametric analysis in the evaluation of patients with airway obstruction using methodologies that explore the functional state and the risk factors that cause the airway obstruction

Estimation of the hydraulic parameters of unsaturated samples by electrical resistivity tomography

In situ and laboratory experiments have shown that electrical resistivity tomography (ERT) is an effective tool to image transient phenomena in soils. However, its application in quantifying soil hydraulic parameters has been limited. In this study, experiments of water inflow in unsaturated soil samples were conducted in an oedometer equipped to perform three-dimensional electrical measurements. Reconstructions of the electrical conductivity at different times confirmed the usefulness of ERT for monitoring the evolution of water content. The tomographic reconstructions were subsequently used in conjunction with a finite-element simulation to infer the water retention curve and the unsaturated hydraulic conductivity. The parameters estimated with ERT agree satisfactorily with those determined using established techniques, hence the proposed approach shows good potential for relatively fast characterisations. Similar experiments could be carried out on site to study the hydraulic behaviour of the entire soil deposi

Enhancing optimization capabilities using the AGILE collaborative MDO framework with application to wing and nacelle design

This paper presents methodological investigations performed in research activities in the field of Multi-disciplinary Design and Optimization (MDO) for overall aircraft design in the EU funded research project AGILE (2015–2018). In the AGILE project a team of 19 industrial, research and academic partners from Europe, Canada and Russia are working together to develop the next generation of MDO environment that targets significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft. The paper introduces the AGILE project structure and describes the achievements of the 1st year that led to a reference distributed MDO system. A focus is then made on different novel optimization techniques studied during the 2nd year, all aiming at easing the optimization of complex workflows that are characterized by a high number of discipline interdependencies and a large number of design variables in the context of multi-level processes and multi-partner collaborative engineering projects. Three optimization strategies are introduced and validated for a conventional aircraft. First, a multi-objective technique based on Nash Games and Genetic Algorithm is used on a wing design problem. Then a zoom is made on the nacelle design where a surrogate-based optimizer is used to solve a mono-objective problem. Finally a robust approach is adopted to study the effects of uncertainty in parameters on the nacelle design process. These new capabilities have been integrated in the AGILE collaborative framework that in the future will be used to study and optimize novel unconventional aircraft configurations