In this study, an unprecedented high gradient up to 230 MV/m that corresponds to a peak surface electric field of more than 520 MV/m has been achieved. The LDSS is a Si wafer illuminated by an …Web
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From the point of view of controlling the migrations of solute and particles during a solidification process, a high-gradient magnetic field mainly exhibits five effects; …Web
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Based on a quasi-3D theory and the modified strain gradient theory, Karamanli and Vo presented the finite element model for the bending, vibration, and buckling behaviors of 2D FG porous microbeams. Keleshteri and Jelovica [ 46 ] investigated the nonlinear vibration analysis of shear deformable 2D porous beams with non-uniform …Web
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The present study investigates the free vibration behavior of rotating beams made of functionally graded materials (FGMs) with a tapered geometry. The material properties of the beams are ...Web
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Modern high-gradient magnetic separation (HGMS) initially originated from a magnetic filter patented in 1937 by Frantz [ 1 ], in which the ferromagnetic matrix of fine …Web
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Jensen et al. studied the stability and the nonlinear dynamics of the pipe conveying high-frequency pulsating fluid. He found that when the average flow velocity exceeded a certain critical value, the pipe lost its stability. ... 4.1.2 Effect of gradient on forced vibration. After the convergent discrete system is derived, HBM is carried out to ...Web
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While the amplitude of the applied mechanical vibrations is very small, in the order of micrometers, by using oscillating magnetic field gradients that are synchronized to the motion, this motion can be imaged to characterize the wave propagation in space and time with high signal-to-noise ratio (SNR). In the most basic implementation of this ...Web
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A 2 DOF model was developed that incorporated both the acoustic resonance and mechanical vibration of a HR integrated with a piezoelectric device. Analyses based on the developed model revealed two distinct resonant frequencies, M and A, where the high-pressure gains occurred in the HR. When coupled with the GRIN PnC, the GRIN-HR …Web
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The Seven Rainbow Chakra Colors and Meanings. #7 Crown – Violet (Purple) – beauty, creativity, spirituality. #6 Third Eye – Indigo – tranquility, understanding, creativeness, heavy sleep. #5 Throat – Blue – clear communication, creativity. #4 Heart – Green – peace, stress lowering, balance, love, healing. #3 Solar Plexus ...Web
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Purpose The functionally graded circular nanoplate is a commonly seen component in the nano-electromechanical system. It is indispensable to examine free vibration behaviors of such an axisymmetric nanostructure subjected to uniformly distributed loads in the radial direction. Although the vibration engineering and …Web
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High gradient magnetic separator is a new type of high intensity magnetic separator, which has strong ability to capture fine and weak magnetic particles, …Web
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A momentum guidance method based on high-frequency gradient features is proposed to filter the Fourier-transformed images by high-frequency filtering. The gradient information of the processed image is added as momentum to the next iteration of the perturbation. The overall effect of the attack is improved.Web
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The drive to higher gradient performance leads to increased concern about vibration and acoustics, and there are fears that these safety concerns will be compounded at ultra-high main field strengths. In this work, we model the field strength dependence of gradient coils, including Lorentz damping. TheseWeb
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This study provides a review of the fundamentals of vibration with an emphasis on the isolation structures, like the porous materials (PM) and mechanical metamaterials, specifically periodic cellular structures …Web
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Wang and Mechefske (18, 19) proposed a vibration analysis and testing of a thin-walled gradient coil model, ... Vegh et al. (93, 94) proposed the use of the wire path correction with optimized variables …Web
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The narrow band gap width caused by local resonance is the shackle for the further development of conventional metamaterials. In this paper, a novel type of hierarchical metamaterial containing parallel multiple resonators is presented, whose ultra-broadband vibration suppression property originates from a rational gradient design. …Web
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The gradient coil insert under investigation has a length of 680 mm, an outer-diameter of 353 mm and a wall thickness of 56.5 mm.It was designed to be installed in a 1.5 T GE MRI or a 4 T Varian/Siemens MRI for scanning small animals. Fig. 1 shows the gradient coil inside a 1.5 T GE MRI. There are three layers of copper windings (referred …Web
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Ground vibration induced by blasting operations is considered one of the most common environmental effects of mining projects. A strong ground vibration can destroy buildings and structures, …Web
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This article compares open-air and whole-body magnetic resonance imaging (MRI) equipment working with a weak magnetic field as regards the methods of its generation, spectral properties of mechanical vibration and acoustic noise produced by gradient coils during the scanning process, and the measured noise intensity. These …Web
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gradient characteristics alone can be used to claim outright superiority. It is the interplay between power, endurance and accuracy that defines a high-quality gradient system and the better definition of gradient performance therefore includes five key parameters as given in figure 1. Figure 1: Gradient performance of the Elition 3.0T …Web
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Free vibration of axially inhomogeneous beams is analyzed. For exponentially graded beams with various end conditions, characteristic equations are derived in closed form. These characteristic or frequency equations can analytically reduce to the classical forms of Euler–Bernoulli beams if the gradient index disappears.Web
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This paper aims to conduct the free vibration analysis of single-layer and laminated composite plates with multiple cutouts based on the scaled boundary finite element method (SBFEM) incorporated with the precise integration method (PIM) and the technique of the degree of freedom transform. It is applicable to a variety of shaped …Web
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high-gradient X-band accelerating systems can be useful in a wide variety of applications beyond linear colliders. These applications include XFELs, compact Compton sources and hadron therapy linacs. I will return to applica-tions in towards the end of the report. …Web
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Gyrotrons are used as high-power sources of coherent radiation operating in pulsed and CW regimes in many scientific and technological fields. In this paper, we discuss two of their numerous applications. The first one is in gyrotron-powered electromagnetic wigglers and undulators. The second one is for driving high-gradient accelerating …Web
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This paper investigates the effect of flexoelectricity on the vibration responses of functionally graded porous piezoelectric sandwich nanobeam reinforced by graphene platelets (GPLs). The Euler–Bernoulli beam theory and the general modified strain gradient theory are employed to formulate the constitutive equations.Web
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In order to investigate the vibration characteristics of the gradient HEMs rod, the TRFRF of four types of hybrid rods with various local resonance masses for 5 periods are calculated. ... The authors would like to thank the High-level Talents Scientific Research of North University of China in 2018 (Grant No. 304/11012305), the Natural Science ...Web
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The prime objective of this study is allocated to comprehensive investigating the free vibration of bi-directional functionally graded (2D-FG) rotary nanobeam with even porosity distribution under different boundary conditions (BCs). The Material properties such as Young's modulus, mass density and nonlocal parameter are supposed to be graded …Web
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1. Introduction. Distributed acoustic sensing (DAS) or distributed vibration sensing (DVS) was developed more than 15 years ago and has since been used for a wide range of monitoring applications [1,2,3,4,5,6].There is a large variety of sensing principles [7,8], most of which are based on the detection of Rayleigh backscatter from coherent …Web
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