341 research outputs found
Corrosion Resistance of Fe-Cr-Al-Si Alloys with Low Chromium Content
Within the framework of this work, alloys with a chromium content of 5 to14 wt%, aluminum from 0 to 4 wt% and silicon from 0 to 4 wt%. The samples were tested for resistance to oxidation with calm dry air (800 ∘C, 0.1 MPa) for 60 hours; in high parameter water (350 ∘C, 16 MPa), for 300 hours; in steam (400 ∘C, 10 MPa), for 72hours and superheated steam (1100 ∘C, 0.1 MPa) for 1 hour.The compositions most resistant to corrosion under the specified conditions were determined, and the existence of a synergistic effect of silicon and aluminum asalloying elements of iron alloys was confirmed.
Keywords: fuel cladding; PWR; tolerant fuel, ferrite steel; corrosive resistance steel
Bott periodicity and stable quantum classes
We use Bott periodicity to relate previously defined quantum classes to
certain "exotic Chern classes" on . This provides an interesting
computational and theoretical framework for some Gromov-Witten invariants
connected with cohomological field theories. This framework has applications to
study of higher dimensional, Hamiltonian rigidity aspects of Hofer geometry of
, one of which we discuss here.Comment: prepublication versio
Effect of exchange electron-electron interaction on conductivity of InGaAs single and double quantum wells in ballistic regime
We report an experimental study of quantum conductivity corrections for
two-dimensional electron gas in a GaAs/InGaAs/GaAs single and double quantum
wells in a wide temperature range (1.8-100) K. We perform a comparison of our
experimental data for the longitudinal conductivity at zero magnetic field to
the theory of interaction-induced corrections to th transport coefficients. In
the temperature range from 10 K up to (45-60) K, wich covers the ballistic
interaction regimes for our samples, a rather good agreement between the theory
and our experimental results has been found
Aseguramiento de protección contra el fuego en complejos industriales de agrupaciones animales
Aquí se presenta el estudio del aseguramiento de la protección contra el fuego en edificios agrupados de un conjunto de ganadería por medio de optimizar las medidas legislativas respectivas y analizar las influencias en la calidad y fiabilidad de los resultados de evaluar riesgos de incendio. Se llevaron a cabo los estudios a través de hacer valoración profesional, calcular riesgos de incendio individuales y simular la evacuación de la gente en el modelo de flujos humanos individual y en cadena. Los aspectos funcionales conceptuales de los edificios del conjunto resultaron en la necesidad de desarrollar soluciones técnicas y estructurales que podrían ayudar a reducir gastos ineficientes y armonizarían los edificios con las exigencias de la protección contra el fuego. El riesgo de incendios individual para los trabajadores del objeto de protección considerado es 2.91x10-7 por año-1 (0.291x10-6 por año), es decir, no sobrepasa el nivel normal establecido por la ley Federal 123-FZ del 22 de Julio de 2008 «Regulaciones Técnicas de las Exigencias a la Protección contra el Fuego". La adopción en el nivel legislativo del sistema de valorar riesgos de incendio creó para los dueños de objetos la oportunidad de optimizar los gastos para asegurar la protección contra el fuego, incluyendo el aseguramiento del nivel exigido de seguridad human
Aseguramiento de protección contra el fuego en complejos industriales de agrupaciones animales
This study deals with ensuring fire safety in buildings of a cluster animal industrial complex by optimizing legislative measures and analyzing factors that affect the quality and reliability of the results of calculating fire risk. The research involved the following methods: expert assessment; calculating individual fire risk; modeling evacuation of people in the form of an individual flow model of human traffic. The conceptual features of the complex's buildings required developing the design and technical solutions that would reduce inefficient costs on the one hand, and, on the other, would ensure meeting fire safety requirements. The individual fire risk for employees of the asset to be protected is 2.91 ×10-7 per year-1 (0.291 ×10-6 per year). That is, it does not exceed the characteristic value established by Federal law No. 123-FZ dated 22.07.2008 'Technical regulations on fire safety'. After the introduction of the fire risk assessment system at the legislative level, the owners of objects have received the opportunity to optimize the cost of fire safety and the required level of human safety.Aquí se presenta el estudio del aseguramiento de la protección contra el fuego en edificios agrupados de un conjunto de ganadería por medio de optimizar las medidas legislativas respectivas y analizar las influencias en la calidad y fiabilidad de los resultados de evaluar riesgos de incendio. Se llevaron a cabo los estudios a través de hacer valoración profesional, calcular riesgos de incendio individuales y simular la evacuación de la gente en el modelo de flujos humanos individual y en cadena. Los aspectos funcionales conceptuales de los edificios del conjunto resultaron en la necesidad de desarrollar soluciones técnicas y estructurales que podrían ayudar a reducir gastos ineficientes y armonizarían los edificios con las exigencias de la protección contra el fuego. El riesgo de incendios indivudual para los trabajadores del objeto de protección considerado es 2.91x10-7 por año-1 (0.291x10-6 por año), es decir, no sobrepasa el nivel normal establecido por la ley Federal 123-FZ del 22 de Julio de 2008 «Regulaciones Técnicas de las Exigencias a la Protección contra el Fuego». La adopción en el nivel legislativo del sistema de valorar riesgos de incendio creó para los dueños de objetos la oportunidad de optimizar los gastos para asegurar la protección contra el fuego, incluyendo el aseguramiento del nivel exigido de seguridad humana
The algorithm of forecasting of the oil well intervention effect
The paper reviews stages of oil well intervention effect forecasting. The proposed algorithm based on regression equation solution automates the process of oil well intervention effect forecasting. An assessment of the hydraulic fracturing effect was provided as a validation of the algorithm. According to assessments results, the suggested regression algorithm allows a 1.87-time decrease of an estimation error according to the error of central tendency
Methodological enhancements in MDO process investigated in the AGILE European project
This paper presents methodological investigations performed in research activities in the field of MDO in overall aircraft design in the ongoing EU funded research project AGILE. AGILE is developing the next generation of aircraft Multidisciplinary Design and Optimization processes, which target significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and describes the achievements of the 1st year (Design Campaign 1) leading to a reference distributed MDO system. A focus is then made on the different novel optimization techniques studied during the 2nd year, all willing to ease the optimization of complex work flows, characterized by high degree of discipline interdependencies, high number of design variables in the context of multi-level and multi-partner collaborative engineering projects. Then the implementation of these methods in the enhanced MDO framework is discussed
Design of the strut braced wing aircraft in the agile collaborative MDO framework
The paper describes the deployment of the AGILE Development Framework to investigate the Strut Braced Wing aircraft configuration. The design process consists of a multilevel multidisciplinary architecture, progressing from the initial conceptual synthesis to the physics based analysis. All the main disciplinary domains, including on board system design and cost assessment, are accounted for in the assembled workflow. Due to the specific characteristics of the Strut Braced Wing configuration, the aeroelastic analysis is the main focus of the study and it is addressed at both high and low fidelity levels. The integration of the engine-wing system is also included in the design process. All the design competences, which are hosted at the different partners, communicate via CPACS (Common Parametric Aircraft Configuration Schema) data schema. All the results generated, including the multidisciplinary design process itself, will be published and made available as part of the AGILE Overall Aircraft Design database
Enhancing optimization capabilities using the AGILE collaborative MDO framework with application to wing and nacelle design
This paper presents methodological investigations performed in research activities in the field of Multi-disciplinary Design and Optimization (MDO) for overall aircraft design in the EU funded research project AGILE (2015–2018). In the AGILE project a team of 19 industrial, research and academic partners from Europe, Canada and Russia are working together to develop the next generation of MDO environment that targets significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft. The paper introduces the AGILE project structure and describes the achievements of the 1st year that led to a reference distributed MDO system. A focus is then made on different novel optimization techniques studied during the 2nd year, all aiming at easing the optimization of complex workflows that are characterized by a high number of discipline interdependencies and a large number of design variables in the context of multi-level processes and multi-partner collaborative engineering projects. Three optimization strategies are introduced and validated for a conventional aircraft. First, a multi-objective technique based on Nash Games and Genetic Algorithm is used on a wing design problem. Then a zoom is made on the nacelle design where a surrogate-based optimizer is used to solve a mono-objective problem. Finally a robust approach is adopted to study the effects of uncertainty in parameters on the nacelle design process. These new capabilities have been integrated in the AGILE collaborative framework that in the future will be used to study and optimize novel unconventional aircraft configurations
- …