151 research outputs found
Influence of Displacement Rate on Residual Shear Strength of Clays
Abstract This paper reports on the results of direct shear tests carried out under controlled displacement rate in the range of 10 -4 -10 2 mm/min, under different normal stresses, with different shear devices. The tests were carried out on a kaolin, a bentonite, their mixtures with sand at various percentages, and the clayey soil of the Costa della Gaveta earthflow. The tests were performed on specimens reconstituted with distilled water as well as with NaCl solutions at various concentrations. Positive rate effects were exhibited by mixtures with c.f. higher than 50% and, consistently, by the natural clayey soil the c.f. of which is about 50%. The residual shear strength increases significantly for shear displacement rate higher than about 1 mm/min. The rate effect increases with the pore solution concentration. The residual shear strength independence of displacement rate has been confirmed in the range 10 -6 - 10 -1 mm/min by the results of shear tests performed under controlled shear stress, with varying chemical conditions of the pore fluid
Cell-to-cell contact modulates Starmerella bacillaris early death in mixed fermentations with Saccharomyces cerevisiae in a couple-dependent way
Cadmium, Copper and Tributyltin effects on fertilization of Paracentrotus lividus (Echinodermata)
Marine environments are continuously being threatened by a large number of xenobi- otics from anthropogenic sources. The effect of chemical pollution on living organisms are numerous and may impair reproductive success of adults species of marine invertebrate and vertebrate through effects on gamete quality. Echinoderms are characterized by external fertilizzation and gametes, free of any type of protection, may be in contact with toxic substances so the reproductive success depends largely on the environment conditions. The purpose of this work is to assess the effects on the in vitro fertiliza- tion of exposure of sea urchin Paracentrotus lividus gametes to xenobiotic substances as CuSO4, CdCl2 and TBTCl. The effect of contaminant were assessed by two experimental set in which gametes were treated with different concentration (0, 10-3, 10-5 10-7 10-9 M) of different substances as CdCl2, CuSO4 and TBTCl. The effects were evaluated as percentage of fertilization. The results showed that the gametes exposure to xenobiotic decreased the percentage of fertilization and that more sensitive to treatment were the sperm cells, propably because the toxic effect affected the motility of the sperm. In conclusion, the absence of fertilization (spermiotoxicity) may submit the toxic effects of these substances to the level of body and may candidate the sea urchis as biosensors for the evaluation of environmental quality
Fallo del tribunal constitucional sobre la despenalización de las relaciones sexuales consentidas entre y con adolescentes de 14 a 18 años: conocimientos, actitudes y experiencias de usuarios y proveedores de los Servicios Diferenciados de Atención Integral de Salud para Adolescentes de las Direcciones de Salud Lima Este y Lima Sur
Identifica los conocimientos, actitudes y experiencias de los usuarios y
proveedores de los servicios de salud sexual y reproductiva de los Servicios Diferenciados
de Atención Integral de Salud para Adolescentes respecto al fallo del Tribunal
Constitucional (TC) sobre la despenalización de las relaciones sexuales consentidas entre
y con adolescentes de 14 a 18 años. Y conocer el contexto de la salud sexual y la salud
reproductiva de los adolescentes antes y después de la aparición de la ley 28704 sobre la
penalización de las relaciones sexuales entre adolescentes. Los que serán insumos que
sirvan como aporte para el establecimiento de nuevas polÃticas públicas, la aplicación
efectiva de las ya existentes y para beneficio de la salud sexual y la salud reproductiva de
hombres y mujeres, durante la etapa crucial de su desarrollo, como es la adolescencia.
Esta investigación es de tipo mixta, cualitativa y cuantitativa. Para el
tipo cuantitativo se ha utilizado un diseño observacional, descriptivo simple y de corte
transversal. Y para el cualitativo se ha utilizado un diseño narrativo. Mediante un muestreo
de tipo no probabilÃstico, intencional y estratificado, se encuestaron a 419 adolescentes de
Lima Este y 497 adolescentes de Lima Sur; 21 proveedores de los servicios de salud sexual
y reproductiva de los Servicios Diferenciados de Atención Integral de Salud para
Adolescentes pertenecientes a la DISA Lima Sur, Lima Este, ESSALUD, Instituto
Nacional de Salud del Niño e Instituto Materno Perinatal. Y se analizaron todos los
documentos gubernamentales que describieran acciones especÃficas en pro de conocer el
estado y la normatividad generada en el campo de la salud sexual y reproductiva de los
adolescentes. Encuentra un alto porcentaje de adolescentes y proveedores de salud, no se encuentran
informados sobre el fallo del Tribunal Constitucional del año 2012 (n=75.5%). Además,
persiste en los adolescentes, la noción que las relaciones sexuales consentidas entre y con
adolescentes de 14 a 18 años, tienen una sanción penal (n=55%). A diferencia del personal
de salud que sà reconoce en qué casos se deberÃa denunciar a la pareja sexual de un
adolescente (n=88.9%). De la revisión de los documentos gubernamentales podemos
señalar que el éxito de la atención integral del adolescente no depende exclusivamente de
la promulgación de acciones legales, sino se muestra una sólida articulación con las
instituciones educativas, los medios de comunicación y la familia
Informed classification of sweeteners/bitterants compounds via explainable machine learning
Perception of taste is an emergent phenomenon arising from complex molecular interactions between chemical compounds and specific taste receptors. Among all the taste perceptions, the dichotomy of sweet and bitter tastes has been the subject of several machine learning studies for classification purposes. While previous studies have provided accurate sweeteners/bitterants classifiers, there is ample scope to enhance these models by enriching the understanding of the molecular basis of bitter-sweet tastes. Towards these goals, our study focuses on the development and testing of several machine learning strategies coupled with the novel SHapley Additive exPlanations (SHAP) for a rational sweetness/bitterness classification. This allows the identification of the chemical descriptors of interest by allowing a more informed approach toward the rational design and screening of sweeteners/bitterants. To support future research in this field, we make all datasets and machine learning models publicly available and present an easy-to-use code for bitter-sweet taste prediction
Optimizing Quality Inspection and Control in Powder Bed Metal Additive Manufacturing: Challenges and Research Directions
Aroma Profile of Montepulciano d'Abruzzo Wine Fermented by Single and Co-culture Starters of Autochthonous Saccharomyces and Non-saccharomyces Yeasts
Montepulciano d'Abruzzo is a native grape variety of Vitis vinifera L., grown in central Italy and used for production of high quality red wines. Limited studies have been carried out to improve its enological characteristics through the use of indigenous strains of Saccharomyces cerevisiae. The main objective of the present work was to test two indigenous strains of S. cerevisiae (SRS1, RT73), a strain of Starmerella bacillaris (STS12), one of Hanseniaspora uvarum (STS45) and a co-culture of S. cerevisiae (SRS1) and S. bacillaris (STS12), in an experimental cellar to evaluate their role in the sensory characteristic of Montepulciano d'Abruzzo wine. A S. cerevisiae commercial strain was used. Fermentations were conducted under routine Montepulciano d'Abruzzo wine production, in which the main variables were the yeast strains used for fermentation. Basic winemaking parameters, some key chemical analysis and aroma compounds were considered. S. cerevisiae strain dynamics during fermentation were determined by molecular methods. The musts inoculated with the co-culture were characterized by a faster fermentation start and a higher content of glycerol after 3 days of fermentation, as well as the musts added with strains S. bacillaris (STS12) and H. uvarum (STS45). At the end of fermentation the parameters studied were quite similar in all the wines. Total biogenic amines (BA) content of all the wines was low. Ethanolamine was the predominant BA, with a concentration ranging from 21 to 24 mg/l. Wines were characterized by esters and alcohols. In particular, 2-phenylethanol, 3-methylbut-1-yl methanoate, and ethyl ethanoate were the major aroma volatile compounds in all wines. Statistical analysis highlighted the different role played by aroma compounds in the differentiation of wines, even if it was impossible to select a single class of compounds as the most important for a specific yeast. The present study represents a further step toward the use of tailored autochthonous strains to impart the specific characteristics of a given wine which are an expression of a specific terroir
High Speed Synchronous Reluctance Machines: Modeling, Design and Limits
An important barrier to the adoption and acceptance of synchronous reluctance (SyR) machines in different applications lies in its non-standardized design procedure. The conflicting requirements incurring at high speeds among electromagnetic torque and structural and thermal limitations can significantly influence the machine performance, leading to a real design challenge. Analytical models used for design purpose lack in accuracy and force the designer to heavily rely on finite element analysis (FEA), at least during the design refinement stage. This becomes even more computational expensive as the speed increases, as the evaluation of the rotor structural behaviour is required. This work presents a computational efficient hybrid analytical-FE design process able to consider all the main limiting design aspects of SyR machine incurring at high speed, namely structural and thermal. As a vessel to investigate the proposed design routine accuracy, several high speed SyR machines have been designed for a wide range of operational speeds (up to 70krpm). The thermal and mechanical factors limiting the high speed operation are deeply analyzed aiming at maximize the mechanical output power. The proposed design approach is then validated by comparison against experimental measurements on a 5kW-50krpm SyR prototype
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