scholarly journals A comparison between cylindrical and cross-shaped magnetic vibration isolators: ideal and practical

2015 ◽  
Vol 64 (4) ◽  
pp. 593-604 ◽  
Author(s):  
D.T.E.H. Van Casteren ◽  
J.J.H. Paulides ◽  
E.A. Lomonova
Keyword(s):  
Sensitivity Analysis ◽  
Resonance Frequency ◽  
Large Diameter ◽  
Volume Ratio ◽  
Cylindrical Structure ◽  
Vibration Isolators ◽  
Small Footprint ◽  
Manufacturing Tolerances ◽  
The Cross ◽  
Tall Structure

Abstract In this paper a cross-shaped isolator consisting of cuboidal magnets and a cylindrical isolator are compared by resonance frequency to volume ratio and shape. Both isolators are capable of obtaining a low resonance frequency, i.e. 0.15 Hz and 0.01 Hz for the cross and cylinder, respectively. The volume of both isolators is comparable, only the shape is different, resulting in a tall structure with a small footprint for the cross and a flat with a large diameter cylindrical structure. A sensitivity analysis shows that due to the large amount of magnets, the cross-shaped isolator is less sensitive to manufacturing tolerances

scholarly journals ZnO-nanostructure-based electrochemical sensor: Effect of nanostructure morphology on the sensing of heavy metal ions

2018 ◽  
Vol 9 ◽  
pp. 2421-2431 ◽  
Author(s):  
Marina Krasovska ◽  
Vjaceslavs Gerbreders ◽  
Irena Mihailova ◽  
Andrejs Ogurcovs ◽  
Eriks Sledevskis ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Electrochemical Sensors ◽  
Zno Nanorods ◽  
Large Diameter ◽  
Chemical Properties ◽  
Volume Ratio ◽  
Zno Nanostructures ◽  
Zno Nanostructure

ZnO nanostructures are promising candidates for use in sensors, especially in electrochemical sensors and biosensors, due to their unique physical and chemical properties, as well as sensitivity and selectivity to several types of contamination, including heavy metal ions. In this work, using the hydrothermal method, nanostructures of ZnO were synthesized in four different morphologies: nanorods, nanoneedles, nanotubes and nanoplates. To determine the peculiarities of adsorption for each morphology, a series of electrochemical measurements were carried out using these nanostructured ZnO coatings on the working electrodes, using aqueous solutions of Pb(NO3)2 and Cd(NO3)2 as analytes with different concentrations. It was found that the sensitivity of the resulting electrochemical sensors depends on the morphology of the ZnO nanostructures: the best results were achieved in the case of porous nanostructures (nanotubes and nanoplates), whereas the lowest sensitivity corresponded to ZnO nanorods with a large diameter (i.e., low surface-to-volume ratio). The efficiency of sedimentation is also related to the electronegativity of adsorbate: it has been shown that all observed ZnO morphologies exhibited significantly higher sensitivity in detecting lead ions compared to cadmium ions.

scholarly journals Continuous tuning of the plasmon resonance frequency of porous gold nanoparticles by mixed oxide layers

2020 ◽  
Vol 27 (6) ◽  
pp. 1583-1588
Author(s):  
Laura Juhász ◽  
Bence Parditka ◽  
Péter Petrik ◽  
Csaba Cserháti ◽  
Zoltán Erdélyi
Keyword(s):  
Gold Nanoparticles ◽  
Resonance Frequency ◽  
Mixed Oxide ◽  
High Surface ◽  
Volume Ratio ◽  
Mixture Ratio ◽  
Optical Extinction ◽  
Oxide Layers ◽  
Porous Gold ◽  
Wide Range

Abstract Porous gold nanoparticles (PGNs) are very popular due to their high surface/volume ratio, moreover they have stronger plasmonic properties than their solid counterparts. These properties make the porous gold nanoparticles very useful for lots of applications, for instance chemical sensors, cancer therapy applications. For applications, however, it is indispensable that the resonance frequency (RF) of a plasmonic structure to be tuneable. In this work we show that the RF can be set in a wide range as desired by coating the PGNs by mixed oxide layers. By changing the composition of the coating layer, that is the mixture ratio, the RF can be shifted practically continuously in a wide range determined by the refractive index of the used oxides. As a demonstration, PGNs were coated with mixed alumina-titania oxide layers (5–7 nm) using plasma-enhanced atomic layer deposition method. The oxide layer, beside as a tuning tool, also stabilises the structure of the PGNs when are exposed to elevated temperature. This is shown by the influence of the temperature (from $$350\, ^{\circ }\hbox {C}$$ 350 ∘ C up to $$900\, ^{\circ }\hbox {C}$$ 900 ∘ C ) on the morphology, and as a consequence the optical extinction spectra, of the oxide coated PGNs.

Frequency Response of Vibration Isolators With Saturating Spring Elements

2005 ◽  
Author(s):  
M. Mahinfalah ◽  
G. Nakhaie Jazar ◽  
M. Rastgaar Aagaah ◽  
N. Mahmoudian
Keyword(s):  
Sensitivity Analysis ◽  
Frequency Response ◽  
Linear Approximation ◽  
Averaging Method ◽  
Piecewise Linear ◽  
Nonlinear Approximation ◽  
Piecewise Linear Approximation ◽  
Hyperbolic Tangent ◽  
Vibration Isolators ◽  
Tangent Function

An investigation using averaging method is carried out to obtain the frequency response of a class of vibration isolators with saturation spring. The saturation characteristics are modeled using a hyperbolic-tangent function. The hyperbolic-tangent saturation function is compared with other popular saturation functions, using piecewise nonlinear approximation. A parameteric study indicates that piecewise linear approximation of saturating functions provide results that are close enough to the results of hyperbolic tangent approximation. A sensitivity analysis of frequency response of the system is also investigated based on the piecewise linear approximation.

A Study on the Resonance Frequency of the Cross-Shaped Piezoelectric Generator According to Change in Elastic Body Thickness and Tip Mass

2012 ◽  
Vol 139 (1) ◽  
pp. 32-39 ◽  
Author(s):  
J. H. Lim ◽  
S. S. Jeong ◽  
N. R. Kim ◽  
S. K. Cheon ◽  
M. H. Kim ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Elastic Body ◽  
Piezoelectric Generator ◽  
The Cross ◽  
Tip Mass

The Study of SCF about Cross Shaped Board - Welded Hollow Spherical Joints

2012 ◽  
Vol 446-449 ◽  
pp. 3108-3114
Author(s):  
Jin Feng Jiao ◽  
Hong Gang Lei
Keyword(s):  
Stress Distribution ◽  
Large Diameter ◽  
Hollow Spheres ◽  
Influence Factors ◽  
Small Diameter ◽  
Thick Wall ◽  
The Cross ◽  
Outside Diameter ◽  
Main Influence

In this paper, the main influence factors of stress-concentrated coefficient Kt of cross shaped board-welded hollow spherical joints were analyzed by ANSYS. Through the combination of 17 specifications of welded hollow spheres and 40 specifications of cross shaped boards to form 122 kinds of cross shaped board–welded hollow spherical Joints, the paper mainly analyzed the influence on stress-concentrated coefficient Kt from some factors as follows: the length of the connection of the cross shaped boards (a)、the thickness of the cross shaped boards (t) , the outside diameter of the welded-hollow spheres (D) , the thickness of the spheres (δ), the weld size (hf) and the cross shaped boards which are cut or not. The analysis results showed: the SCF of the joints and some factors（a、t、D、δand hf） in all .A cross shaped board to cut its corner or not affected the stress distribution of the joints and the biggest difference between 12%; In the cross shaped boards connected the same length, when it rises to some degree, the influence of (δ) on ( Kt) is smaller; Along with the thickness of the large diameter welded hollow spheres increases, the slope of the stress-concentrated coefficient Kt increases; It is better to choose the hollow spheres with the small diameter or thick wall, and choose the cross shaped boards which shall be a little thinner, and also increase the connected length between the welded hollow spheres and the cross shaped boards; When the weld size is larger than or equal to 12 millimeters, SCF gently changes.

Synthesis and Adsorption Properties of Crosslinked Starch Microspheres (CSM)

2011 ◽  
Vol 418-420 ◽  
pp. 702-705
Author(s):  
Cong Jian Li ◽  
Qin Tie Lin ◽  
Qian Jun Liu ◽  
Han Ping Pan ◽  
Ru Ting Zheng
Keyword(s):  
Graft Copolymerization ◽  
Removal Rate ◽  
Methyl Violet ◽  
Volume Ratio ◽  
Adsorption Properties ◽  
Orthogonal Test ◽  
Cross Linking ◽  
Optimal Conditions ◽  
Single Factor ◽  
The Cross

Starch as the material, MBAA as the cross-linking agent, Tween60 and Span60 as the emulsifier, K2S2O8-Na2SO4 as the initiator, the cyclohexane as the oil phase and the removal rate of methyl violet as an index, crosslinked starch microspheres (CSM) was synthetized by means of reverse suspension emulsion and graft-copolymerization method through orthogonal test and single factor optimization experiment. The results showed the optimal conditions of the preparation of the crosslinked starch microspheres(CSM) were as follow: the concentration of the starch is 5%, the dosage of the MBAA, initiator and emulsifier are 0.125g, 0.5g and 0.6g, the volume ratios between the Span60 and Tween60 is 85:15, and the volume ratio between the cyclohexane and water is 4:1.

scholarly journals Sensitivity Analysis for the Cross-Match Test, With Applications in Genomics

2010 ◽  
Vol 105 (491) ◽  
pp. 1005-1013 ◽  
Author(s):  
Ruth Heller ◽  
Shane T. Jensen ◽  
Paul R. Rosenbaum ◽  
Dylan S. Small
Keyword(s):  
Sensitivity Analysis ◽  
The Cross ◽  
Cross Match

Multi-channel Active Vibration Isolation for the Control of Underwater Sound Radiation From A Stiffened Cylindrical Structure: A Numerical Study

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Huang Xiuchang ◽  
Zhang Zhiyi ◽  
Zhang Zhenhua ◽  
Hua Hongxing
Keyword(s):  
Cylindrical Shell ◽  
Vibration Isolation ◽  
Sound Radiation ◽  
Spatial Average ◽  
Far Field ◽  
Underwater Sound ◽  
Cylindrical Structure ◽  
Vibration Isolators ◽  
Active Vibration ◽  
Active Vibration Isolation

Numerical simulation of vibration control of a submerged stiffened cylindrical structure with active vibration isolators is presented. Vibration transmission from vibrating machinery to the cylindrical structure through the active vibration isolators is analyzed by a numerical model synthesized from frequency response functions (FRFs) and impedances. The coupled finite element/boundary element (FE/BE) method is employed to study the vibro-acoustic behavior of the fluid-loaded cylindrical structure. Sound pressure in the far-field is calculated in terms of the pressure and normal acceleration of the outer surface of the cylindrical shell. An adaptive multichannel control based on the filtered-x least mean squares (FxLMS) algorithm is used in the active vibration isolation. Simulation results have demonstrated that suppression of vibration of the four elastic foundations attached to the cylindrical shell will reduce the spatial-average mean-square velocity and the instantaneous radiated power of the cylindrical shell. As a result, suppression of vibration of the foundations leads to attenuation of sound radiation in the far-field induced by the radial displacement dominant mode of the shell. Moreover, vibration suppression is greatly influenced by the strong couplings among control channels. According to these results, it can be concluded that the proposed method is effective in the analysis of underwater sound radiation control of cylindrical structures.

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