Search results for " Structural"

Genetic Normalized Convolution

2011

Normalized convolution techniques operate on very few samples of a given digital signal and add missing information, trough spatial interpolation. From a practical viewpoint, they make use of data really available and approximate the assumed values of the missing information. The quality of the final result is generally better than that obtained by traditional filling methods as, for example, bilinear or bicubic interpolations. Usually, the position of the samples is assumed to be random and due to transmission errors of the signal. Vice versa, we want to apply normalized convolution to compress data. In this case, we need to arrange a higher density of samples in proximity of zones which c…

High-pressure polymorphs of gadolinium orthovanadate: X-ray diffraction, Raman spectroscopy, and ab initio calculations

2019

We present a study of the different high-pressure polymorphs of $\mathrm{GdV}{\mathrm{O}}_{4}$ and its stability. Powder x-ray diffraction and Raman experiments show a phase transition from a zircon- to a scheelite-type structure taking place at 6.8(4) GPa. Ab initio density functional theory calculations support this conclusion. The equations of state of these two phases are reported. In addition, we studied the pressure evolution of the Raman modes for the zircon and scheelite phases, showing good agreement between calculations and experiments. For the sake of completeness, we performed optical-absorption measurements up to 16 GPa, showing a band-gap collapse at the transition point. Beyo…

Low temperature structural transformations on the (001) surface of SrTiO 3 single crystals

2020

This work was supported by the Ministry of Education and Science of Ukraine under the contract M/51–2019 within the framework of the Program of Ukrainian–Latvian Scientific and Technical Cooperation and Latvian–Ukranian Grant LV-UA/2018/2. Authors are indebted to L.L. Rusevich, G. Zvejnieks, V.P. Gnezdilov and A. Glamazda for stimulating discussions.

Photocurrent Spectroscopy Applied to the Characterization of Compositionally and Structurally Graded Materials: from Thin Films to Nanostructures

2010

Subsurface treatment of a contact subjected to a hertz pressure

2013

Abstract The study proposes an approach allowing the favorable modification of the stresses field of a structure subjected to a Hertzian contact. It is based on the study of a classic Hertzian contact in the presence of subsurface circular defects. The idea is to limit the field of tangential stresses without large increasing of the global stress (Von Mises) of the system. The location of the defects is made according to the mechanical parameters of the contact (Fn, has, z). The results of the numerical calculations (FEM) are compared with photoelastic measurements and highlight an excellent correlation. The location of the defect on the symmetry axis (x=0) is the dominating parameter for t…

Closure to “Stage–Discharge Relationship for an Upstream Inclined Grid with Transversal Bars” by C. Di Stefano and V. Ferro

2016

Numerical modeling and design of a disk-type rotating permanent magnet induction pump

2016

Abstract Electromagnetic induction pumps with rotating permanent magnets appear to be the most promising devices to transport liquid metals in high-temperature applications. Here we present a numerical methodology to simulate the operation of one particular modification of these types of pumps: a disk-type induction pump. The numerical model allows for the calculation and analysis of the flow parameters, including the pressure–flow rate characteristics of the pump. The simulations are based on an iterative fully coupled scheme for electromagnetic and hydrodynamic solvers. The developed model is verified by comparing with experimental data obtained using a Pb-Bi loop test facility, for press…

Stochastic Response Of Fractionally Damped Beams

2014

Abstract This paper aims at introducing the governing equation of motion of a continuous fractionally damped system under generic input loads, no matter the order of the fractional derivative. Moreover, particularizing the excitation as a random noise, the evaluation of the power spectral density performed in frequency domain highlights relevant features of such a system. Numerical results have been carried out considering a cantilever beam under stochastic loads. The influence of the fractional derivative order on the power spectral density response has been investigated, underscoring the damping effect in reducing the power spectral density amplitude for higher values of the fractional de…

A study of the potential influence of frame coolant on HCLL-TBM nuclear response

2007

Abstract Within the European Fusion Technology Programme, the Helium-Cooled Lithium Lead (HCLL) breeding blanket concept is one of the two EU lines to be developed for a long term fusion reactor, in particular with the aim of manufacturing a test blanket module (TBM) to be implemented in ITER. The HCLL-TBM is foreseen to be located in an ITER equatorial port, being housed inside a steel-supporting frame, actively cooled by pressurized water. This supporting frame has been designed to house two different TBMs providing two cavities separated by a dividing plate 20 cm thick. As the nuclear response of HCLL-TBM could vary with the supporting frame configuration and composition, a parametric st…

3D MHD lead–lithium liquid metal flow analysis and experiments in a Test-Section of multiple rectangular bends at moderate to high Hartmann numbers

2013

Abstract Experiments with liquid lead–lithium (Pb–Li) were carried out in a stainless steel (SS) Test Section (TS) consisting of multiple 90° bends for various flow rates and applied magnetic fields of up to 4 T. Characteristic MHD flow parameter Hartmann number, Ha ( = B 0 a σ / μ , Ha2 is the ratio of electromagnetic force to viscous force) and interaction parameter, N ( = σ a B 0 2 / ρ U , N is the ratio of electromagnetic force to inertial force) of these experiments were varied from Ha = 515 to 2060 and N = 25 to 270 by changing the applied magnetic field and flow rates respectively. Three dimensional numerical simulations have been carried out using MHD module of FLUENT code. The meas…