398 research outputs found

    Polypyrrole-Fe2O3 nanohybrid materials for electrochemical storage

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    We report on the synthesis and electrochemical characterization of nanohybrid polypyrrole (PPy) (PPy/Fe2O3) materials for electrochemical storage applications. We have shown that the incorporation of nanoparticles inside the PPy notably increases the charge storage capability in comparison to the “pure” conducting polymer. Incorporation of large anions, i.e., paratoluenesulfonate, allows a further improvement in the capacity. These charge storage modifications have been attributed to the morphology of the composite in which the particle sizes and the specific surface area are modified with the incorporation of nanoparticles. High capacity and stability have been obtained in PC/NEt4BF4 (at 20 mV/s), i.e., 47 mAh/g, with only a 3% charge loss after one thousand cyles. The kinetics of charge–discharge is also improved by the hybrid nanocomposite morphology modifications, which increase the rate of insertion–expulsion of counter anions in the bulk of the film. A room temperature ionic liquid such as imidazolium trifluoromethanesulfonimide seems to be a promising electrolyte because it further increases the capacity up to 53 mAh/g with a high stability during charge–discharge processes

    Perspectives and Integration in SOLAS Science

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    Why a chapter on Perspectives and Integration in SOLAS Science in this book? SOLAS science by its nature deals with interactions that occur: across a wide spectrum of time and space scales, involve gases and particles, between the ocean and the atmosphere, across many disciplines including chemistry, biology, optics, physics, mathematics, computing, socio-economics and consequently interactions between many different scientists and across scientific generations. This chapter provides a guide through the remarkable diversity of cross-cutting approaches and tools in the gigantic puzzle of the SOLAS realm. Here we overview the existing prime components of atmospheric and oceanic observing systems, with the acquisition of ocean–atmosphere observables either from in situ or from satellites, the rich hierarchy of models to test our knowledge of Earth System functioning, and the tremendous efforts accomplished over the last decade within the COST Action 735 and SOLAS Integration project frameworks to understand, as best we can, the current physical and biogeochemical state of the atmosphere and ocean commons. A few SOLAS integrative studies illustrate the full meaning of interactions, paving the way for even tighter connections between thematic fields. Ultimately, SOLAS research will also develop with an enhanced consideration of societal demand while preserving fundamental research coherency. The exchange of energy, gases and particles across the air-sea interface is controlled by a variety of biological, chemical and physical processes that operate across broad spatial and temporal scales. These processes influence the composition, biogeochemical and chemical properties of both the oceanic and atmospheric boundary layers and ultimately shape the Earth system response to climate and environmental change, as detailed in the previous four chapters. In this cross-cutting chapter we present some of the SOLAS achievements over the last decade in terms of integration, upscaling observational information from process-oriented studies and expeditionary research with key tools such as remote sensing and modelling. Here we do not pretend to encompass the entire legacy of SOLAS efforts but rather offer a selective view of some of the major integrative SOLAS studies that combined available pieces of the immense jigsaw puzzle. These include, for instance, COST efforts to build up global climatologies of SOLAS relevant parameters such as dimethyl sulphide, interconnection between volcanic ash and ecosystem response in the eastern subarctic North Pacific, optimal strategy to derive basin-scale CO2 uptake with good precision, or significant reduction of the uncertainties in sea-salt aerosol source functions. Predicting the future trajectory of Earth’s climate and habitability is the main task ahead. Some possible routes for the SOLAS scientific community to reach this overarching goal conclude the chapter

    Limits of conservation agriculture to overcome low crop yields in sub-Saharan Africa

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    Conservation agriculture (CA) has become a dominant paradigm in scientific and policy thinking about the sustainable intensification of food production in sub-Saharan Africa. Yet claims that CA leads to increasing crop yields in African smallholder farming systems remain controversial. Through a meta-analysis of 933 observations from 16 different countries in sub-Saharan African studies, we show that average yields under CA are only slightly higher than those of conventional tillage systems (3.7% for six major crop species and 4.0% for maize). Larger yield responses for maize result from mulching and crop rotations/intercropping. When CA principles are implemented concomitantly, maize yield increases by 8.4%. The largest yield benefits from CA occur in combination with low rainfall and herbicides. We conclude that although CA may bring soil conservation benefits, it is not a technology for African smallholder farmers to overcome low crop productivity and food insecurity in the short term

    ANÁLISIS SENSORIAL DE LA CARNE BUFALINA (Bubalus bubalis) EN LA CIUDAD DE PALMIRA, COLOMBIA.

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    Con el objetivo de determinar las propiedades organolépticas de la carne bufalina, se realizó un estudio basado en un análisis sensorial, en 102 personas de la ciudad de Palmira (Colombia) con un rango de edad comprendida entre 11 y 65 años, de ambos sexos. A cada persona se le proporcionaron 100g de carne bufalina en cortes de primera calidad, asadas al carbón. Se empleo la metodología afectiva con una escala de satisfacción hedónica verbal de 5 puntos y mediante lassiguientes preguntas se evaluaron características como: 1. ¿Qué tanto le gusta el sabor?, 2.¿Qué tanto le gusta la consistencia (Blanda y jugosa)?, 3.¿Qué tanto le gusta este producto en general?. Para el análisis estadístico se empleo un análisis factorial de correspondencia múltiple con clasificación jerárquica, análisis exploratorio unidimensional; adicionalmente se trabajo con la tabla de Burt para observar bidimensionalmente el comportamiento de las variables. En el análisis estadístico encontró que el sabor de la carne de búfalo “Le gusto mucho” al 63.7% de los encuestados, en cuanto a la consistencia (blanda y jugosa) el 65.5%, afirmó que “Le gusto mucho” la carne, mientras que el 4.9% de la población encuestada consideró que la consistencia no correspondía a sus expectativas, calificándola con un disgusto en el concepto “Le disgustó un poco” y “Le disgustó mucho” la carne bufalina. En la evaluación general del producto los encuestados aceptaron en un 90.2% el producto con un calificativo entre: “Le gustó un poco” y “Le gusto mucho”, siendo más frecuente la respuesta de las personas encuestadas a las cuales “Le gusto mucho” la carne de búfalo. Se puede estimar que el mercado de la carne bufalina tiene una demanda potencial del 81.3% del total de la muestra encuestada, esto permite estimar que el parámetro de aceptación para este tipo de carne fue alto.Palabras clave: Búfalos, carne, clasificación jerárquica, Análisis sensorial, Palmira.Buffaloes, meat, Hierarchic classification, sensorial analysis, Palmir

    Short communication: Genetic analysis of lactation curves in buffaloes, using Wood’s model

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    Aim of study: To estimate the heritability and genetic correlations for lactation curve traits in buffaloes.Area of study: The buffalo cows were raised on properties located in the states of São Paulo, Ceará and Rio Grande do Norte, Brazil.Material and methods: The individual parameters of Wood’s model ( , , and ) were obtained using a non-linear mixed model. Peak yield (PY), peak time (PT) and lactation persistency (LP) were also calculated. These individual parameters were employed in multi-trait analysis with the milk yield (MY) using Bayesian inference.Main results: The heritability estimates were of low to moderate magnitudes, with values ranging from 0.156 ( ) to 0.299 (PY). The estimates for genetic correlation between the Wood’s parameters and MY were of low to high magnitude and ranged from -0.533 (  and MY) to 0.983 (PY and MY).Research highlights: The heritability estimates obtained indicate that the traits studied can be used in animal breeding programs

    Desempenho agronômico de mandioca de mesa manejada com irrigação e uso de cobertura plástica do solo.

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    Resumo Apesar da mandioca ser reconhecida pela sua elevada tolerância à seca, a irrigação vem apresentando resultados satisfatórios. Entretanto, poucos estudos vêm sendo desenvolvidos visando a determinação dos efeitos da cobertura do solo, da irrigação e da combinação de ambos no desenvolvimento da cultura. O objetivo deste estudo foi determinar a influência da irrigação e da cobertura plástica do solo, no desempenho agronômico de mandioca de mesa. O plantio foi feito em canteiros, no sistema de fileira dupla com as manivas-sementes implantadas na vertical em espaçamento de 0,60 m entre linhas e 0,80 m entre plantas. Foram aplicados os tratamentos canteiro desnudo sem irrigação, canteiro coberto com plástico de polietileno preto sem irrigação, canteiro desnudo com irrigação e canteiro coberto com plástico de polietileno preto com irrigação. As irrigações foram por aspersão convencional, com base no balanço diário de água do solo na profundidade efetiva do sistema radicular da mandioca nos diferentes estágios de desenvolvimento da cultura. Os caracteres avaliados em duas safras foram: produtividade de parte aérea, produtividade de raízes, porcentagem de amido nas raízes e tempo para a cocção. A expressão dos caracteres produtividade de raízes, peso da parte aérea e teor de amido nas raízes, foi influenciada pelo manejo da irrigação e pela cobertura do solo. A utilização individual das tecnologias de irrigação e de cobertura plástica do solo, proporcionaram aumentos de produtividade de raízes de 55% e 13%, respectivamente, e quando foram utilizadas em conjunto a produtividade de raízes aumentou 89%

    Adherence to the Mediterranean diet and lymphoma risk in the European Prospective Investigation into Cancer and Nutrition

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    There is growing evidence of the protective role of the Mediterranean diet (MD) on cancer. However, no prospective study has yet investigated its influence on lymphoma. We evaluated the association between adherence to the MD and risk of lymphoma and its subtypes in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The analysis included 476,160 participants, recruited from ten European countries between 1991 and 2001. Adherence to the MD was estimated through an adapted relative Mediterranean diet (arMED) score excluding alcohol. Cox proportional hazards regression models were used while adjusting for potential confounders. During an average follow‐up of 13.9 years, 3,136 lymphomas (135 Hodgkin lymphoma (HL), 2,606 non‐Hodgkin lymphoma and 395 lymphoma NOS) were identified. Overall, a 1‐unit increase in the arMED score was associated with a 2% lower risk of lymphoma (95% CI: 0.97; 1.00, p‐trend=0.03) while a statistically non‐significant inverse association between a high versus low arMED score and risk of lymphoma was observed (HR: 0.91 (95% CI 0.80; 1.03), p‐trend=0.12). Analyses by lymphoma subtype did not reveal any statistically significant associations. Albeit with small numbers of cases (N= 135), a suggestive inverse association was found for HL (HR 1‐unit increase= 0.93 (95% CI: 0.86; 1.01), p‐trend=0.07). However, the study may have lacked statistical power to detect small effect sizes for lymphoma subtype. Our findings suggest that an increasing arMED score was inversely related to the risk of overall lymphoma in EPIC, but not by subtypes. Further large prospective studies are warranted to confirm these findings

    Association between anthropometry and lifestyle factors and risk of B cell lymphoma: an exposome wide analysis.

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    To better understand the role of individual and lifestyle factors in human disease, an exposome-wide association study was performed to investigate within a single study anthropometry measures and lifestyle factors previously associated with B-cell lymphoma (BCL). Within the European Prospective Investigation into Cancer and nutrition study, 2,402 incident BCL cases were diagnosed from 475,426 participants that were followed-up on average 14 years. Standard and penalized Cox regression models as well as principal component (PC) analysis were used to evaluate 84 exposures in relation to BCL risk. Standard and penalized Cox regression models showed a positive association between anthropometric measures and BCL and multiple myeloma/plasma cell neoplasm (MM). The penalized Cox models additionally showed the association between several exposures from categories of physical activity, smoking status, medical history, socioeconomic position, and diet and BCL and/or the subtypes. PC analyses confirmed the individual associations but also showed additional observations. The PC5 including anthropometry, was positively associated with BCL, diffuse large B-cell lymphoma (DLBCL), and MM. There was a significant positive association between consumption of sugar and confectionary (PC11) and follicular lymphoma risk, and an inverse association between fish and shellfish and Vitamin D (PC15) and DLBCL risk. The PC1 including features of the Mediterranean diet and diet with lower inflammatory score showed an inverse association with BCL risk, while the PC7, including dairy, was positively associated with BCL and DLBCL risk. Physical activity (PC10) was positively associated with DLBCL risk among women. This study provided informative insights on the etiology of BCL
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