Effect of Heating Rates and Composition on the Thermal Decomposition of Nitrate Based Molten Salts

AbstractA detailed analysis on the thermal degradation of nitrate based molten salts evaluating the influence of different impurities and heating rates in their maximum working temperature is presented. Determining the maximum operating temperature is of interest when searching for new heat transfer fluids (HTF) for high temperature solar thermal applications as it limits the thermodynamic efficiency of the power block. Thermogravimetric analysis is performed on potassium nitrate, sodium nitrate, sodium nitrite, the binary system Solar Salt, and the ternary Hitec. The kinetics of the thermal decomposition reactions are investigated through iso-conversional analysis. The effect of adding some common impurities such us NaCl and Na2CO3 on the multi-component nitrate salts is evaluated. It was found that impurities such as Na2CO3 can enhance the thermal stability of Hitec salt, leading to higher thermal decomposition temperatures. For solar salt, impurities such as NaCl can enhance the thermal stability of solar salt at 10K·min-1, while adding Na2CO3 can have the opposite effect. For nitrate based molten salts used in TES and HTF systems in CSP a reduction on the purity required for the materials can present some operational advantages besides cost reduction

A survey of potential insect vectors of the plant pathogenic bacterium Xylella fastidiosa in three regions of Spain

The emergence of a rapid-spreading olive disease associated with Xylella fastidiosa in southern Italy represents a high risk to susceptible crops in other countries of the Mediterranean basin, if insect vectors occur in the region. The goal of this study was to identify xylem-feeding Auchenorrhyncha that could potentially act as vectors of X. fastidiosa in three regions of Spain (Andalucía, Murcia and Madrid). Samplings with sweep net and stem tap were carried out in October/2004 on grapevines and adjacent crops (olives, nectarine, citrus, Prunus spp.), ornamental trees and herbaceous weeds. Yellow sticky cards were placed in ten vineyards located across 100 km in Andalucía and in three vineyards distant 10-15 km apart in Murcia. Specimens of frequently-trapped species were tested by nested- or multiplex-PCR for the presence of X. fastidiosa. The Typhlocybinae leafhopper, Austroasca (Jacobiasca) lybica (Hemiptera: Cicadellidae) was the most abundant species in vineyards and citrus orchards. Planthoppers (Hemiptera: Fulgoroidea) and psyllids (Hemiptera: Psylloidea) were prevalent on olives. Cicadellinae leafhoppers (known as sharpshooters), which are major vectors of X. fastidiosa in the Americas, were not found in the samples. The only potential vectors were spittlebugs (Hemiptera: Cercopoidea) collected on Populus sp., herbaceous and on conifer trees (Pinus halepense); the spittlebug Neophileanus sp. was common on conifer trees adjacent to a vineyard in Jumilla. None of the insect samples tested positive for X. fastidiosa by PCR assays. However, spittlebugs already associated with susceptible crops in Spain may allow fast spread of X. fastidiosa in case this pathogen is introduced.We also acknowledge financial support from the CNPq-CSIC bilateral grant no. 2004BR0004 and EU grant ICA4-CT-2001-10005.Peer Reviewe

Cauliflower mosaic virus is preferentially acquired from the phloem by its aphid vectors

Cauliflower mosaic virus (CaMV) is transmitted in a non-circulative manner by aphids following the helper strategy. Helper proteins P2 and P3 act as a bridge between virions and the aphid cuticle. Electronic monitoring of aphid stylet activities (EPG technique), transmission tests and electron microscopy showed that CaMV is preferentially acquired from the phloem by its most common aphid vectors, Brevycorine brassicae and Myzus persicae. We also found that CaMV is semipersistently transmitted and that the rate of acquisition does not follow a typical bimodal curve. Instead, the virus could be acquired from non-phloem tissues at a low and fairly constant rate after one or more intracellular punctures within a few minutes, but the probability of acquisition rose significantly when aphids reached the phase of committed ingestion from the phloem. The acquisition rate of CaMV did not increase with increasing number of intracellular punctures, but the total duration of intracellular puncture was one of the variables selected by the stepwise logistic regression model used to fit the data that best explained acquisition of CaMV. Furthermore, aphids reaching the phloem faster had a higher probability of acquiring the virus. Our results support the hypothesis that multiple intracellular punctures of epidermal and mesophyll cells result in loading aphids with the CaMV-encoded aphid transmission factor (P2), and that aphids, in most cases, subsequently acquire CaMV particles during phloem sap ingestion. Consistently, immunoelectron microscopy showed that P3–virions are frequently found in the sieve element lumen, whereas P2 could not be detected.We are indebted to the Spanish Ministry of Science and Technology (Research Grant, no. AGL:2000-2006) for funding this work. Also, we acknowledge the Comunidad Autónoma de Madrid (Spain) and CAPES (Brazil) for funding the fellowships awarded to I.P. and S.L., respectively. M.D. was awarded a fellowship from the ACI-JC of the French Ministry for Research. We thank Takii Ltd seed company for kindly providing turnip ‘Just Right’ seedsPeer reviewe

Dispersal of aphids, whiteflies and their natural enemies under photoselective nets

Integrated Pest Management of insects includes several control tactics, such as the use of photoselective nets, which may reduce the flight activity of insects. Limiting the dispersal of pests such as aphids and whiteflies is important because of their major role as vectors of plant viruses, while a minor impact on natural enemies is desired. In this study, we examined for the first time the dispersal ability of three vector species, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer) (Hemiptera: Aphididae), in cages covered with photoselective nets. Contrary to the results obtained with aphids, the ability of the whitefly B. tabaci, to reach the target plant was reduced by photoselective nets. In a second set of experiments, the impact of UV-absorbing nets on the visual cues of two important predator species, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), was evaluated. The anthocorid was caught in higher numbers in traps placed under regular nets, whereas the mites preferably chose environments in which the UV radiation was attenuated. We have observed a wide range of effects that impedes generalization, although photoselective nets have a positive effect on pest management of whiteflies and aphids under protected environments

dRYBP counteracts chromatin-dependent activation and repression of transcription

Chromatin dependent activation and repression of transcription is regulated by the histone modifying enzymatic activities of the trithorax (trxG) and Polycomb (PcG) proteins. To investigate the mechanisms underlying their mutual antagonistic activities we analyzed the function of Drosophila dRYBP, a conserved PcG- and trxG-associated protein. We show that dRYBP is itself ubiquitylated and binds ubiquitylated proteins. Additionally we show that dRYBP maintains H2A monoubiquitylation, H3K4 monomethylation and H3K36 dimethylation levels and does not affect H3K27 trimethylation levels. Further we show that dRYBP interacts with the repressive SCE and dKDM2 proteins as well as the activating dBRE1 protein. Analysis of homeotic phenotypes and post-translationally modified histones levels show that dRYBP antagonizes dKDM2 and dBRE1 functions by respectively preventing H3K36me2 demethylation and H2B monoubiquitylation. Interestingly, our results show that inactivation of dBRE1 produces trithorax-like related homeotic transformations, suggesting that dBRE1 functions in the regulation of homeotic genes expression. Our findings indicate that dRYBP regulates morphogenesis by counteracting transcriptional repression and activation. Thus, they suggest that dRYBP may participate in the epigenetic plasticity important during normal and pathological development

Conditional Facilitation of an Aphid Vector, Acyrthosiphon pisum, by the Plant Pathogen, Pea Enation Mosaic Virus

Plant pathogens can induce symptoms that affect the performance of insect herbivores utilizing the same host plant. Previous studies examining the effects of infection of tic bean, Vicia faba L. (Fabales: Fabaceae), by pea enation mosaic virus (PEMV), an important disease of legume crops, indicated there were no changes in the growth and reproductive rate of its primary vector the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). Here, we report the results of laboratory experiments investigating how A. pisum responded to PEMV infection of a different host plant, Pisum sativum L., at different stages of symptom development. Aphid growth rate was negatively related to the age of the host plant, but when they were introduced onto older plants with well-developed PEMV symptoms they exhibited a higher growth rate compared to those developing on uninfected plants of the same age. In choice tests using leaf discs A. pisum showed a strong preference for discs from PEMV-infected peas, probably in response to visual cues from the yellowed and mottled infected leaves. When adults were crowded onto leaves using clip-cages they produced more winged progeny on PEMV-infected plants. The results indicate that PEMV produces symptoms in the host plant that can enhance the performance of A. pisum as a vector, modify the production of winged progeny and affect their spatial distribution. The findings provide further evidence that some insect vector/plant pathogen interactions could be regarded as mutualistic rather than commensal when certain conditions regarding the age, stage of infection and species of host plant are met

Flying capacity of Psyttalia concolor and Chrysoperla carnea under a UV-absorbing net (Bionet®) in presence and absence of crop.

Field studies were conducted in walk-in tunnels to determine the flying capacity in the presence and absence of crop, of the parasitoid Psyttalia concolor and the predator Chrysoperla carnea under a UV-absorbent net (Bionet®). Yellow sticky cards were used for insect recovery but neither P. concolor nor C. carnea were very attracted to them, thus captures were too low to permit any meaningful comparisons. Bionet® did not seem to affect the mobility of any natural enemy irrespective of the trap location and monitoring hour. Climatic conditions inside nets were very extreme (average temperatures very high and relative humidity very low) threatening insect survival. New experiments are being developed, trying to find new attractants that permit a significant capture of both natural enemies

Mejores prácticas de manejo para el uso optimizado del suelo y el agua en la agricultura

Chinese translation: Yun Xie, Lixin Chen, Jie Tang, Zhaoqi Fu, Meng Zhang, Hanlin Dong.English version available at http://dx.doi.org/10.20350/digitalCSIC/13964Spanish version available at http://dx.doi.org/10.20350/digitalCSIC/13985在Shui项目框架下，综合论述了农业系统水土资源优化利用的最佳管理措施BMPs（Best Management Practices）。编写本报告的主要原因如下： （1）为与该项目有关或无关的任何读者，总结以水土资源优化利用为目标的各类最佳管理措施（BMPs）技术。 （2）确定在相关的政策计划中，尤其是共同农业政策，如何界定最佳管理措施（BMPs）及需求，以便指导政策利益相关者进行情景模拟和提出改进建议。 （3）为项目内部和外部使用者提供最佳管理措施（BMPs）的标准化术语定义及通用框架。 （4）与Shui项目课题1、2、5合作，确保选用的各类最佳管理措施（BMPs）已通过试验、田间尺度模型模拟、以及所在区域利益相关者的反馈（WP5）进行了充分的评估与分析。 全文对最佳管理措施的综述均基于Shui项目背景，包括了中欧不同的农业气候区和以下农业系统： （1）雨养经果林 （2）灌溉经果林 （3）雨养谷物轮作 （4）灌溉谷物轮作 本报告的灌溉用水涉及到低质水，包括废水利用和灌溉循环水利用。基于土壤水文学研究平台创新管理欧洲和中国种植系统的水资源短缺问题（SHUI） 欧洲委员会 项目资助号： 773903Peer reviewe

Best management practices for optimized use of soil and water in agriculture

These BMPs have been always reviewed in the context of the SHui project, which covers different agro-climatic regions across Europe and China and these agricultural systems: 1- Rainfed tree crops. 2- Irrigated tree crops. 3- Cereal based rotations under rainfed conditions. 4- Cereal based rotations under irrigation. Regarding use of water for irrigation, this document will also cover the use of low-quality water, including wastewater, and the use of recycled water for irrigation.Spanish version available at http://dx.doi.org/10.20350/digitalCSIC/13985Chinese version available at http://hdl.handle.net/10261/253611This document provides a comprehensive review of Best Management Practices (BMPs) for optimized used soil and water in agricultural systems within the context of the SHui project. This document, which also has been translated into Spanish and Chinese could be use: 1- To provide to any reader an overview of the technical description of available options of BMPs for optimizing soil and water use. 2- To identify how BMPs are defined and requested in relation to large policy instruments, particularly the Common Agricultural Policy (CAP), to provide guidance on simulated scenario as well as on recommendations for improvement to policy stakeholders. 3- To provide a common framework, within the project as well for external users, for the definition of BMPs using a standardize terminology, and an appraisal on how some of the most common hydrologic models can be used, or not, to introduce the effect of these BMPs on scenario analysis.Soil Hydrology research platform underpinning innovation to manage water scarcity in European and Chinese cropping systems. SHui. European Commission. Grant Agreement number 773903.Peer reviewe

Mejores prácticas de manejo para el uso optimizado del suelo y el agua en la agricultura

Estas MPM siempre se han revisado en el contexto del proyecto SHui, que cubre diferentes regiones agroclimáticas en Europa y China y estos sistemas agrícolas: 1- Cultivos arbóreos de secano. 2- Cultivos arbóreos de regadío. 3- Rotaciones a base de cereales en condiciones de secano. 4- Rotaciones a base de cereales bajo riego. En cuanto al uso de agua para riego, este documento también aborda el uso de agua de baja calidad, incluidas las aguas residuales, y el uso de agua reciclada para riego.Traducción y edición en español: Federico Julián Fuentes y José Alfonso Gómez, Grupo Operativo Cereal Agua.Versión en inglés disponible en: http://dx.doi.org/10.20350/digitalCSIC/13964Versión en chino disponible en: http://hdl.handle.net/10261/253611Este documento es la traducción al castellano de la versión original en inglés fruto de la colaboración entre el Grupo Operativo Nacional Cereal Agua (de la EIP-Agri) y el proyecto SHui (del programa H2020 de la Comisión Europea). El mismo proporciona una revisión integral de las Mejores Prácticas de Manejo (MPM) para el optimizar el uso sostenible de los recursos suelo y agua en los sistemas agrícolas dentro del contexto del proyecto SHui. Este documento, que además de la versión original inglesa ha sido traducido al español y al chino, podría utilizarse para: 1- Proporcionar a cualquier lector una visión general de la descripción técnica de las opciones disponibles de MPM para optimizar el uso sostenible de los recursos suelo y agua. 2- Identificar cómo se definen y se regulan las MPM en relación con los grandes instrumentos regulatorios, en particular la Política Agrícola Común (PAC), a fin de proporcionar orientación sobre escenarios en que se implementaran esas MPM, así como facilitar la formulación recomendaciones para su mejor implementación por diferentes agentes. 3- Proporcionar un marco común, tanto dentro del proyecto como para los usuarios externos, para la definición de MPM utilizando una terminología estandarizada, así como una evaluación de cómo algunos de los modelos hidrológicos más comunes pueden usarse, o no, para introducir el efecto de estas MPM sobre estudios de análisis de escenarios en los que se introduzcan algunas de estas prácticas.Grupo Operativo Cereal Agua. Para su constitución, al grupo le ha sido concedida una subvención del Fondo Europeo Agrícola de Desarrollo Rural en el marco del Programa Nacional de Desarrollo Rural 2014-2020 del Ministerio de Agricultura, Pesca y Alimentación. La creación de los Grupos Operativos de ámbito nacional ha sido posible a través de la Asociación Europea para la Innovación en materia de productividad y sostenibilidad agrícola (AEI-AGRI). La creación y funcionamiento del grupo operativo supraautonómico CEREAL-AGUA está cofinanciada en un 80% con el Fondo Europeo Agrícola de Desarrollo Rural (FEADER) de la Unión Europea, y en un 20% por el Ministerio de Agricultura, Pesca y Alimentación en el marco del Programa Nacional de Desarrollo Rural 2014-2020, siendo la inversión total de 507.930,00 €.-- Soil Hydrology research platform underpinning innovation to manage water scarcity in European and Chinese cropping systems. SHui. Comisión Europea. Identificador del acuerdo de subvención 773903.Peer reviewe