326 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
Spherical Bondi accretion onto a magnetic dipole
Quasi-spherical supersonic (Bondi-type) accretion to a star with a dipole
magnetic field is investigated using resistive magnetohydrodynamic simulations.
A systematic study is made of accretion to a non-rotating star, while sample
results for a rotating star are also presented. A new stationary subsonic
accretion flow is found with a steady rate of accretion to the magnetized star
smaller than the Bondi accretion rate. Dependences of the accretion rate and
the flow pattern on the magnetic momentum of the star and the magnetic
diffusivity are presented. For slow star's rotation the accretion flow is
similar to that in non-rotating case, but in the case of fast rotation the
structure of the subsonic accretion flow is fundamentally different and
includes a region of ``propeller'' outflow. The methods and results described
here are of general interest and can be applied to systems where matter
accretes with low angular momentum.Comment: 15 pages, 15 figures, used emulapj.st
Short-term Mechanical Properties of Fe-Cr-Al-Si Alloys
The purpose of this work is to study the short-term mechanical properties of Fe-Cr-AlSi-based alloys. Within the framework of this work, alloys with a chromium content of 5 to 14 wt%, aluminum from 0 to 4 wt%, and silicon from 0 to 4 wt% are considered. The samples were tested in three different states - in the deformed state (cold rolling by 80%), and also after annealing at a temperature of 450 and 650 ∘C with a duration of 1000 h.As a result, the characteristics of the strength and plasticity of alloys in the deformed state, as well as after provoking annealing, were obtained. It is shown that embrittlement isn’t observed in the investigated composition region and annealing conditions, and the strength of the alloys is directly proportional to the sum of the alloying elements Al + Si.
Keywords: cladding; VVER; tolerant fuel, ferrite steel; Corrosion-resistant steel, tensile strength, yield strengt
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
Diffraction effects in the Recoil-Frame Photoelectron Angular Distributions of Halomethanes
Citation: Bomme, C., Anielski, D., Savelyev, E., Boll, R., Erk, B., Bari, S., . . . Rolles, D. (2015). Diffraction effects in the Recoil-Frame Photoelectron Angular Distributions of Halomethanes. 635(11). doi:10.1088/1742-6596/635/11/112020We have measured the Recoil Frame-Photoelectron Angular Distributions (RF-PADs) for inner-shell photoionization of CH3F, CH3I and CF3I halomethane molecules for photoelectron energies up to 300 eV detected within a 4? solid angle in the gas-phase. For high kinetic energies, the RF-PADs are dominated by diffraction effects that encode information on the molecular geometry. © Published under licence by IOP Publishing Ltd
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
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