On the origin of negative target currents during laser ablation of polyethylene

The exposure of a target to a focused laser beam results in the occurrence of a time-varying current between the target itself and the grounded vacuum chamber. This current is composed by three distinct phases, namely the ignition phase, in which the laser pulse drives the electron emission, while electrons coming from the ground through the target holder balance the positive charge generated on the target. The active phase appears at post-pulse times and it is characterized by the presence of peaked structures in the time-resolved current, representing characteristics of the target composition. Lastly, the afterglow phase is determined by a current of electrons flowing from the target to the ground. During the active phase of the target current resulting from polymers ablation with an UV KrF laser, negative target current peaks are observed, whose origin is still unknown. We investigate the dependence of these current structures on the dimensions of the target, using ultra-high molecular weight polyethylene disks of different thickness

DOUBLE SIZE FULLJET FIELD RAINFALL SIMULATOR FOR COMPLEX INTERRILL AND RILL EROSION STUDIES

Field observations and consecutive modelling of soil erosion events proved to be essential for understanding and predicting erosion and sediment transport. An experimental approach often utilizes a large variety of rainfall simulators. In this technical note a complex methodology is introduced, using a mobile rainfall simulator developed at the Czech Technical University in Prague. An experimental setup with two watered plots (16 + 1 m2) was established, which enables simultaneous measurements in two scales and monitoring of surface runoff, flow velocity, infiltration, sediment subsurface flow, vegetation cover effect suspended solids and phosphorus transport, surface roughness and surface evolution under rainfall and other variables. The simulator is built on a trailer transportable by car with folding arm carrying four FullJet WSQ nozzles operating independently. The configuration and water pressure 0.7 bar leads to the total watered area 2.4 x 9.6 m. Average drop size (d50) reaches 1.75 mm for 0.7 bar pressure. Christiansen uniformity index CU reaches 85%. A selection of experimental results highlights both the advantages and the weaknesses of the presented experimental setup

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

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

Методологичен подход за изграждане на типологията на ферми от гледна точка на здравето на почвата случаят на ЕС

[EN] Soil health is a significant problem in agriculture which demands a tailor-made approach. The study aims to develop a methodological approach for farm typology construction in terms of soil health. TUdi project, under which was made this study, aims to transform unsustainable management of soils in key cropping systems in Europe and China, developing an integrated platform of alternatives to reverse soil degradation. Thus, the focus is on small, medium, and large EU farms, which produce in the three key cropping systems – grassland, cereal-based rotation, and tree crops. It was applied principal component analysis based on which it was constructed four factors, related to soil health. The results from this analysis was used to feed up the cluster analysis together with other significant variables. The developed farm typology consists of four farm types. From practical point of view was introduced a methodology which allow to determine the type of each farm according the TUdi typology.[BG] Здравето на почвата е значим проблем в аграрната икономика, които изисква прилагането на индивидуален подход. Целта на настоящата разработка е да се предложи методология за конструиране на типология на ферми, свързана със здравето на почвата. Анализът е реализиран по проект „Tudi“, който цели трансформирането на неустойчивото управление на почвите в ключови системи в Европа и Китай, разработвайки интегрирана платформа за алтернативи за обръщане на деградацията на почвата. В тази връзка фокусът е насочен към малки, средни и големи ферми от страни, членки на ЕС, които произвеждат продукция в трите ключови системи на земеделието – зърнени култури, трайни насаждения и пасища. Използван е анализ на главните компоненти за конструирането на четири фактора, свързани със здравето на почвата. Тези фактори, заедно с други ключови променливи, са анализирани чрез клъстерен анализ за формирането на четири типа ферми. Предложен е подход за определяне на мястото на всяка една ферма в тази типология.The study was developed with the financial help of the European Union’s Horizon 2020 Research and Innovation action under the project “Transforming Unsustainable management of soils in key agricultural systems in EU and China. Developing an integrated platform of alternatives to reverse soil degradation” – TUdi with grant agreement No 101000224.Peer reviewe

Measuring, modelling and managing gully erosion at large scales: A state of the art

Soil erosion is generally recognized as the dominant process of land degradation. The formation and expansion of gullies is often a highly significant process of soil erosion. However, our ability to assess and simulate gully erosion and its impacts remains very limited. This is especially so at regional to continental scales. As a result, gullying is often overlooked in policies and land and catchment management strategies. Nevertheless, significant progress has been made over the past decades. Based on a review of >590 scientific articles and policy documents, we provide a state-of-the-art on our ability to monitor, model and manage gully erosion at regional to continental scales. In this review we discuss the relevance and need of assessing gully erosion at regional to continental scales (Section 1); current methods to monitor gully erosion as well as pitfalls and opportunities to apply them at larger scales (section 2); field-based gully erosion research conducted in Europe and European Russia (section 3); model approaches to simulate gully erosion and its contribution to catchment sediment yields at large scales (section 4); data products that can be used for such simulations (section 5); and currently existing policy tools and needs to address the problem of gully erosion (section 6). Section 7 formulates a series of recommendations for further research and policy development, based on this review. While several of these sections have a strong focus on Europe, most of our findings and recommendations are of global significance.info:eu-repo/semantics/publishedVersio

Deux dessins du Louvre et la peinture de manuscrits en Bohême vers 1400

Krása Josef. Deux dessins du Louvre et la peinture de manuscrits en Bohême vers 1400. In: Scriptorium, Tome 23 n°1, 1969. pp. 163-176

Close Range Photogrammetry and Thermal Imagery in Monitoring of Soil Moisture in Dam Structures of Historical Fishponds

Degradation of reservoir dams can lead to water percolation through dam structure. Here, close-range photogrammetry and UAV (Unmanned Aerial Vehicle) thermal imagery can be used to monitor differences in dam moisture. The article presents a study of the dam of Podvinak Fishpond (Czech Republic). The TDR (Time Domain Reflectometry) data (soil moisture), the Theta probe data (soil moisture), and the temperature data of the dam top profile and the grassed area below the dam were compared. Analysis focused on the comparison between sampled data, and UAV data obtained by Optris TIM 450 (Portsmouth, USA) and Flir Tau2 336 (Wilsonville, USA) IR cameras. Based on the study, the spectral resolution, the accuracy of the results, and the reliability of both UAV monitoring systems is similar

Erozní mapa ČR a její využití

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Operational USLE-based modelling of soil erosion in Czech Republic, Austria, and Bavaria - differences in model adaptation, parametrization, and data availability

In the European Union, soil erosion is identified as one of the main environmental threats, addressed with a variety of rules and regulations for soil and water conservation. The by far most often officially used tool to determine soil erosion is the Universal Soil Loss Equation (USLE) and its regional adaptions. The aim of this study is to use three different regional USLE-based approaches in three different test catchments in the Czech Republic, Germany, and Austria to determine differences in model results and compare these with the revised USLE-base European soil erosion map. The different regional model adaptations and implementation techniques result in substantial differences in test catchment specific mean erosion (up to 75% difference). Much more pronounced differences were modelled for individual fields. The comparison of the region-specific USLE approaches with the revised USLE-base European erosion map underlines the problems and limitations of harmonization procedures. The EU map limits the range of modelled erosion and overall shows a substantially lower mean erosion compared to all region-specific approaches. In general, the results indicate that even if many EU countries use USLE technology as basis for soil conservation planning, a truly consistent method does not exist, and more efforts are needed to homogenize the different methods without losing the USLE-specific knowledge developed in the different regions over the last decades