Ultrasound focuser: A multi-cylindrical source configuration and entrapped particles dynamics

Ultrasonics ◽  
2019 ◽  
Vol 97 ◽  
pp. 38-45 ◽  
Author(s):  
Majid Rajabi ◽  
Alireza Mojahed ◽  
Aria Hajiahmadi
Keyword(s):  
Cylindrical Source ◽  
Particles Dynamics

scholarly journals Study on the Influence of the Ball Material on Abrasive Particles’ Dynamics in Ball-Cratering Thin Coatings Wear Tests

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 668
Author(s):  
Gustavo Pinto ◽  
Andresa Baptista ◽  
Francisco Silva ◽  
Jacobo Porteiro ◽  
José Míguez ◽  
...  
Keyword(s):  
Aisi 304 ◽  
Thin Coatings ◽  
Iron And Steel ◽  
Test Configuration ◽  
Abrasive Particles ◽  
Aisi 52100 ◽  
Aisi 304 Steel ◽  
Aisi 52100 Steel ◽  
Steel Balls ◽  
Particles Dynamics

Micro-abrasion remains a test configuration hugely used, mainly for thin coatings. Several studies have been carried out investigating the parameters around this configuration. Recently, a new study was launched studying the behavior of different ball materials in abrasive particles’ dynamics in the contact area. This study intends to extend that study, investigating new ball materials never used so far in this test configuration. Thus, commercial balls of American Iron and Steel Institute (AISI) 52100 steel, Stainless Steel (SS) (AISI) 304 steel and Polytetrafluoroethylene (PTFE) were used under different test conditions and abrasive particles, using always the same coating for reference. Craters generated on the coated samples’ surface and tracks on the balls’ surface were carefully observed by Scanning Electron Microscopy (SEM) and 3D microscopy in order to understand the abrasive particles’ dynamics. As a softer material, more abrasive particles were entrapped on the PTFE ball’s surface, generating grooving wear on the samples. SS AISI 304 balls, being softer than the abrasive particles (diamond), also allowed particle entrapment, originating from grooving wear. AISI 52100 steel balls presented particle dynamics that are already known. Thus, this study extends the knowledge already existing, allowing to better select the ball material to be used in ball-cratering tests.

A test apparatus for secondary ion mass spectrometry

1983 ◽  
Vol 61 (4) ◽  
pp. 535-542 ◽  
Author(s):  
N. Klaus ◽  
J. D. Brown
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Low Cost ◽  
Ion Source ◽  
Channel Electron Multiplier ◽  
Electron Multiplier ◽  
Spherical Source ◽  
Ion Mass Spectrometry ◽  
Cylindrical Source ◽  
Secondary Ion

A low cost test device for secondary ion mass spectrometry (SIMS) components is described. It consists of a turbomolecular pumped vessel containing an insulated sample stage on an x−y manipulator, extraction optics, quadrupole mass filter, and channel electron multiplier. The construction and characteristics of a cylindrical and a spherical saddlefield ion source are described. The output of the cylindrical source is 10−4 A cm−2 whereas that of the spherical source is in the order of 10−3 A cm−2 at voltages up to 9 kV and at a beam divergence of 4°.

Radiation Loading of a Cylindrical Source in a Fluid-Filled Cylindrical Cavity Embedded Within a Fluid-Saturated Poroelastic Medium

2002 ◽  
Vol 69 (5) ◽  
pp. 675-683 ◽  
Author(s):  
S. M. Hasheminejad ◽  
H. Hosseini
Keyword(s):  
Seismic Waves ◽  
Acoustic Radiation ◽  
Surrounding Medium ◽  
Practical Importance ◽  
Closed Form Solution ◽  
Form Solution ◽  
Radiation Impedance ◽  
Harmonic Field ◽  
Cylindrical Source ◽  
Water Saturated

Radiation loading on a vibrating structure is best described through its radiation impedance. In the present work the modal acoustic radiation impedance load on an infinitely long cylindrical source harmonically excited in circumferentially periodic (axially independent) spatial pattern, while positioned concentrically within a fluid cylinder, which is embedded in a fluid-saturated unbounded elastic porous medium, is computed. This configuration, which is a realistic idealization of an acoustic logging tool suspended in a fluid-filled borehole within a permeable surrounding formation (White, J. E., 1983, Underground Sound Application of Seismic Waves, Elsevier, Amsterdam, Fig. 5.29, p. 183), is of practical importance with a multitude of possible applications in seismo-acoustics and noise control engineering. The formulation utilizes the Biot phenomenological model to represent the behavior of the sound in the porous, fluid-saturated, macroscopically homogeneous and isotropic surrounding medium. Employing the appropriate wave-harmonic field expansions and the pertinent boundary conditions for the given boundary configuration, a closed-form solution in the form of an infinite series is developed and the resistive and reactive components of modal radiation impedances are determined. A numerical example for a cylindrical surface excited in vibrational modes of various order, immersed in a water-filled cavity which is embedded within a water-saturated Ridgefield sandstone environment, is presented and several limiting cases are examined. Effects of porosity, frame stiffness, source size, and the interface permeability condition on the impedance values are presented and discussed.

scholarly journals A New Simulation Model for Vertical Spiral Ground Heat Exchangers Combining Cylindrical Source Model and Capacity Resistance Model

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1339 ◽  
Author(s):  
Takao Katsura ◽  
Takashi Higashitani ◽  
Yuzhi Fang ◽  
Yoshitaka Sakata ◽  
Katsunori Nagano ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Simulation Model ◽  
High Speed ◽  
Approximate Equation ◽  
Source Model ◽  
Calculation Model ◽  
Ground Heat Exchangers ◽  
Ground Source ◽  
Equivalent Length ◽  
Cylindrical Source

Considering the heat capacity inside vertical spiral ground heat exchanger (VSGHEX) in the simulation is one of the most noteworthy challenge to design the ground source heat pump (GSHP) system with VSGHEXs. In this paper, a new simulation model for VSGHEXs is developed by combining the ICS model with the CaRM. The developed simulation model can consider the heat capacity inside VSGHEX and provide dynamic calculation with high speed and appropriate precision. In order to apply the CaRM, the equivalent length was introduced. Then, the equivalent length was approximated by comparing the results of the CaRM and the numerical calculation. In addition, the calculation model of the VSGHEX was integrated into the design and simulation tool for the GSHP system. The accuracy of the tool was verified by comparing with the measurements. The error between supply temperatures of the measurements and calculation is approximately 2 °C at the maximum. Finally, assuming GSHP systems with VSGHEXs, whose spiral diameter was 500 mm and depth was 4 m, were installed in residential houses in Japan, the required numbers of VSGHEXs were estimated. The results showed a strong correlation between the total heating or cooling load and the required number. Therefore, the required number can be estimated by using the simplified approximate equation.

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