Search results for "element"
showing 10 items of 13601 documents
High-Order Harmonics Generation in Atomic and Molecular Zinc Plasmas
2021
We demonstrate the variations of single harmonic resonance enhancement during high-order harmonics generation in zinc-containing atomic and molecular species at the conditions of single-color and two-color pumps of laser-induced plasmas by applying different laser sources. We show how selenides of this metal notably modify the enhancement of single (9th, 15th or 16th) harmonic compared with purely atomic zinc plasmas. The variations of single harmonic enhancement are demonstrated using fixed (806 nm) and tunable (1280–1440 nm) radiation.
Cambio de percepción de los niños de preescolar sobre su ambiente, mediante una intervención educativa con enfoque local.
2015
La investigación se desarrolla con 300 infantes de doce centros escolares de preescolar en cinco comunidades aledañas a los Manglares y Humedales de Tuxpan. El objetivo fue determinar si una intervención educativa cambia la percepción sobre su medio. Se realiza un diagnóstico solicitando a los pequeños que elaboraran un dibujo bajo el título ¿Cómo es mi medio ambiente?. Se diseña e implementa una intervención educativa pertinente al contexto y alineada con el currículum Programa de Estudios 2011/ Preescolar, específicamente con el campo formativo de Exploración y Conocimiento del mundo, fomentando una actitud reflexiva sobre la importancia del aprovechamiento adecuado de los recursos natura…
EOF-Library: Open-source Elmer FEM and OpenFOAM coupler for electromagnetics and fluid dynamics
2019
EOF-Library is a software that couples Elmer and OpenFOAM simulation packages. It enables efficient internal field interpolation and communication between the finite element and the finite volume frameworks. The coupling of the two packages is based on the Message Passing Interface, which results in low latency, high data bandwidth and parallel scalability. Potential applications are magnetohydrodynamics, convective cooling of electrical devices, industrial plasma physics and microwave heating. In this work we introduce the software and perform interpolation accuracy and parallel scaling tests by sending a known scalar distribution between the two codes. Keywords: Elmer, FEM, OpenFOAM, FVM,…
Geographic Information System of Primary Carbon Deposit of Mangrove Forest in Merauke District, Indonesia
2020
Emission factors with increasing carbon dioxide (CO2) originating from various human activities are one of the causes of global climate change. The mangrove forest is a type of plant that has a great ability to absorb carbon in the atmosphere and store it in biomass through photosynthesis. Merauke Regency has 20 separate parts based on regional administration, but primary Mangrove forests are only found in ten regions (district). The results of research carried out using geographic information systems (GIS) in processing primary Mangrove forest data based on 2016 land cover map data in Merauke district, the area of primary mangrove forest reaches 184.402 ha, which is spread in various regio…
Failure Rate Measurement on Silicon Diodes Reverse Polarized at High Temperature
2017
This paper calculates the failure rate on reversed polarized silicon diodes with the aim to justify, experimentally, the rules of the European Space Agency (ESA) which are referred to the component life’s extension, the reliability increase and the end of life performance enhancement, by using oversized devices (derating rules). In order to verify the derating rules, 80 silicon diodes are used, which are reverse polarized in a high temperature environment. The diodes are divided in 4 groups of 20 diodes, applying a different voltage to each group, in order to relate the failure rate to the applied derating rule. The experiment described in this paper is developed using a temperature acceler…
Towards automatic calibration of 2-D flood propagation models
2010
Abstract. Hydraulic models for flood propagation description are an essential tool in many fields and are used, for example, for flood hazard and risk assessments, evaluation of flood control measures, etc. Nowadays there are many models of different complexity regarding the mathematical foundation and spatial dimensions available, and most of them are comparatively easy to operate due to sophisticated tools for model setup and control. However, the calibration of these models is still underdeveloped in contrast to other models like e.g. hydrological models or models used in ecosystem analysis. This has two primary reasons: first, lack of relevant data against which the models can be calibr…
Effects of hydrogen-charging on the properties of S235JR steel
2017
The paper presents the test results of the S235JR steel susceptibility to damage under the influence of hydrogen. The test of mechanical properties was performed on the basis of a static stretch test of non-hydrogenated samples and after cathodic polarization. Electrochemical measurements for the assessment of corrosion resistance of non-hydrogenated and hydrogenated steels were carried out using open circuit potential measurement and registering of potentiodynamic polarization curves in a three-electrode measuring system. Hydrogenation was carried out for between 3 and 24 hours in a solution of 0.1 N sulfuric acid (VI) with the addition of 2 mg/dm 3 of arsenic oxide (III) at an electric cu…
Multi-elemental EDXRF mapping of polluted soil from former horticultural land.
2004
The distribution of major and trace elements was systematically investigated by use of energy dispersive X-ray fluorescence spectrometry (EDXRF) on a former horticultural soil. The purpose of the study was to combine mapping of soil element concentration levels with multivariate statistics for characterisation of soil metal pollution in relation to previous and present land use. A 1-ha study site was chosen from a former horticulture where a previous preliminary survey indicated increased concentration levels of toxic elements. The soil was sampled from the top 20 cm of the soil surface in a 10×10-m grid-like pattern covering the 1-ha study area. In addition, three soil profiles were studie…
Metals in sediments of lakes in Latvia
1995
Abstract The concentrations and speciation forms of Pb, Cu, Ni, Cd, Zn, and Mn have been determined in sediments from 49 lakes thoroughout Latvia to study the impact of different pollutant sources and to estimate the background pollution level. Regional variation in pollutant distributions of Pb, Cu, and Cd concentrations is due to anthropogenic load. The enrichment of metals in the top layer of sediments is an estimate of the environmental pollution level. In regions with no known pollution sources, this enrichment was not typical. Another factor that determines metal concentrations in sediments is the organic matter production and sedimentation in eutrophic water bodies.
Direct electricity production from coconut oil - the electrooxidation of coconut oil in an acid electrolyte
2018
Supplying more and more energy is an essential task of today's energy industry. In the last few decades, in addition to traditional methods of energy production, alternative energy sources have been developing at a fast rate. One of the devices that can use these sources is the fuel cell (FC). FCs can be a power source of the future mainly due to their high efficiency, their low impact on the environment and the possibility of powering with different fuels. Most often, FCs are powered by hydrogen. However, issues with its cheap production and storage are the reasons for seeking new fuels for FCs. Yet it must be a fuel that will provide a zero or low emission level. One of these fuels can be…