Search results for " Flow"

Re: Technique of internal mammary dissection using pectoralis major flap to prevent contour deformities

2009

Genome architecture enables local adaptation of Atlantic cod despite high connectivity

2017

Adaptation to local conditions is a fundamental process in evolution; however, mechanisms maintaining local adaptation despite high gene flow are still poorly understood. Marine ecosystems provide a wide array of diverse habitats that frequently promote ecological adaptation even in species characterized by strong levels of gene flow. As one example, populations of the marine fish Atlantic cod (Gadus morhua) are highly connected due to immense dispersal capabilities but nevertheless show local adaptation in several key traits. By combining population genomic analyses based on 12K single-nucleotide polymorphisms with larval dispersal patterns inferred using a biophysical ocean model, we show…

Plastic yielding of glass in high-pressure torsion apparatus

2018

International audience; Hardness measurements performed at room temperature have demonstrated that glass can flow under elevated pressure, whereas the effect of high pressure on glass rheology remains poorly quantified. Here, we applied a high-pressure torsion (HPT) apparatus to deform SCHOTT SF6 â glass and attempted to quantify the effect of pressure and temperature on the shear deformation of glass subjected to pressures from 0.3 GPa to 7 GPa and temperatures from 25 ℃ to 496 ℃. Results show that the plastic yield deformation was occurring during the HPT experiments on the SF6 glass at elevated temperature from 350 ℃ to 496 ℃. The yield stress of SF6 glass decreases with increasing tempe…

Analytical description of solid particles kinematics due to a fluid flow and application to the depiction of characteristic kinematics in cold sprayi…

2017

Abstract In several multiphase flow applications such as fluidization, thermal spraying, atomization manufacturing and so on, the Newton's law is widely enacted to formulate the particle/fluid kinematic interaction and then to compute particles kinematics. This paper provides analytical solutions of the Newton's law in its time-dependent formulation or simplified formulation, the latter being a reduction of the time dependent problem into a spatial description of the particle motion. It was found that the velocity solution is strictly similar in both cases so that the simplified formulation is viable. The W_ 1 branch of the Lambert's function yields the analytical particle residence time an…

Strategies for numerical simulation of linear friction welding of metals: a review

2017

Linear friction welding (LFW) is a solid-state joining process used to weld non-axisymmetric components. Material joining is obtained through the reciprocating motion of two specimens undergoing an axial force. During this process, the heat source is determined by the frictional work transformed into heat. This results in a local softening of the material and plays a key role in the onset of the bonding conditions. In this paper, a critical analysis of the different approaches used to simulate the LFW processes is provided. The focus of the paper is the comparison of different modeling strategies and the most relevant outputs available, i.e. temperature, strain and stress distribution, mate…

Stability of melt flow during magnetic sonication in a floating zone configuration

2018

Combined static and alternating magnetic fields are shown to create an oscillating pressure that can cause cavitation in molten metals. A time-averaged flow is also excited, consisting of two tori squeezed to thin boundary layers. Flow instability develops as a standing wave between these tori.

Wear and corrosion resistant performance of thermal-sprayed Fe-based amorphous coatings: A review

2019

Abstract Thermal sprayed Fe-based amorphous coatings exhibit excellent wear and corrosion resistance, and thus have been widely utilized for enhancing the performance of material surfaces. In this paper, important research progresses achieved in regards to deposition technologies and properties of thermal sprayed Fe-based amorphous coatings are reviewed. In particular, the dependence of wear and corrosion resistance of the coatings on processing parameters, e.g., kinetic energy, particle size, gas flow rate, and heat treatment temperature are summarized. Moreover, the utilization of reinforced phases and alloy elements for enhancing the wear and corrosion resistance of the coatings are pres…

On the mechanics of magnetic fluids with field-induced phase transition: application to Couette flow

2018

The influence of Brownian diffusion and magnetophoresis, which are followed by phase transition, on the characteristics of a stationary plane Couette flow of magnetic fluid in a non-uniform magnetic field is discussed. The phase transition conditions in magnetic fluids are assumed as a natural restriction to the particle concentration increase in a non-uniform magnetic field. Profiles of the particles' concentration are calculated, and dependences of the volume magnetic force and of the viscous force are established. © 2018 Institute of Physics, University of Latvia.

Control flow strategy in a receiver coil for nuclear magnetic resonance for imaging

2020

A mathematical discussion is introduced to describe the receiver coil characterizing a nuclear magnetic resonance for imaging, starting from a general shape of the conductor. A set of different inductance calculations have been introduced, varying the shape of the conductor. The inductance calculation led to a general expression of the magnetic field of a single coil characterized by a rectangular shape. A dynamic model of the receiver coil has been developed to represent the natural frequencies that characterize the operational bandwidth. A nonstationary control strategy is implemented to make a real time changing of the operational bandwidth. The frequency response of the coil generates …

Multiphysical Modeling of Transport Phenomena During Laser Welding of Dissimilar Steels

2016

Abstract The success of new high-strength steels allows attaining equivalent performances with lower thicknesses and significant weight reduction. The welding of new couples of steel grades requires development and control of joining processes. Thanks to high precision and good flexibility, laser welding became one of the most used processes for joining of dissimilar welded blanks. The prediction of the local chemical composition in the weld formed between dissimilar steels in function of the welding parameters is essential because the dilution rate and the distribution of alloying elements in the melted zone determines the final tensile strength of the weld. The goal of the present study i…