An experimental study of the forces generated by the collapse of transient cavities in water

1960 ◽  
Vol 7 (4) ◽  
pp. 596-609 ◽  
Author(s):  
I. R. Jones ◽  
D. H. Edwards
Keyword(s):  
Shock Wave ◽  
Experimental Study ◽  
Experimental Investigation ◽  
Peak Pressure ◽  
Surface Damage ◽  
Peak Force ◽  
Cavity Collapse ◽  
The Moment ◽  
Pressure Bar ◽  
Collapse Process

The paper describes an experimental investigation of the pressures developed at the seat of collapse of cavities in water. Single transient cavities, generated by a spark discharge, are allowed to collapse on the end of a piezoelectric pressure-bar gauge which measures the variation of thrust with time. It is shown that both the peak force and duration of the cavity collapse pulse are functions of the cavity lifetime. From an estimate of the minimum radius attained by the cavity and the peak force, the peak pressure on collapse is found to be at least 10,000 atm. Streak schlieren photographs of the collapse process show that a shock wave is radiated into the water at the moment of collapse and that the cavity rebounds. At the collapse of the rebound cavities the pressures developed are comparable with those developed by the collapse of the initial cavity, and these probably contribute materially to cavitational surface damage.

The Collapse of a Gas Bubble Attached to a Solid Wall by a Shock Wave and the Induced Impact Pressure

1983 ◽  
Vol 105 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Y. Tomita ◽  
A. Shima ◽  
K. Takahashi
Keyword(s):  
Shock Wave ◽  
Experimental Study ◽  
Pressure Transducer ◽  
High Speed ◽  
Solid Wall ◽  
Wall Pressure ◽  
Gas Bubble ◽  
High Speed Camera ◽  
The Impact ◽  
Collapse Process

An experimental study was made on the collapse of a gas bubble attached to a solid wall by a shock wave. The collapse process of the bubble and the induced impact wall pressure were measured simultaneously by means of a high speed camera and a pressure transducer, respectively. Consequently, it was found that the impact wall pressure was very sensitive to the factors such as the bubble size, the strength of shock wave and the distance from the origin of shock wave to the gas bubble, and in some cases it became larger than that generated by a shock wave directly impinging on the solid wall without a gas bubble.

Liquid-Phase Peak Force Infrared Microscopy

2020 ◽  
Author(s):  
Haomin Wang ◽  
Joseph M. González-Fialkowski ◽  
Wenqian Li ◽  
Yan Yu ◽  
Xiaoji Xu
Keyword(s):  
Liquid Phase ◽  
Spatial Resolution ◽  
Shear Force ◽  
Polymer Surface ◽  
Surface Damage ◽  
Peak Force ◽  
Infrared Microscopy ◽  
Contact Mode ◽  
Force Microscopy ◽  
Hydrogen Deuterium

Atomic force microscopy-infrared microscopy (AFM-IR) provides a route to bypass Abbe’s diffraction limit through photothermal detections of infrared absorption. With the combination of total internal reflection, AFM-IR can operate in the aqueous phase. However, AFM-IR in contact mode suffers from surface damage from the lateral shear force between the tip and sample, and can only achieve 20~25-nm spatial resolution. Here, we develop the liquid-phase peak force infrared (LiPFIR) microscopy that avoids the detrimental shear force and delivers an 8-nm spatial resolution. The non-destructiveness of the LiPFIR microscopy enables <i>in situ</i> chemical measurement of heterogeneous materials and investigations on a range of chemical and physical transformations, including polymer surface reorganization, hydrogen-deuterium isotope exchange, and ethanol-induced denaturation of proteins. We also perform LiPFIR imaging of the budding site of yeast cell wall in the fluid as a demonstration of biological applications. LiPFIR unleashes the potential of in liquid AFM-IR for chemical nanoscopy.

An Experimental Investigation of the Efficacy of Lawyers' Letters

2002 ◽  
Vol 21 (1) ◽  
pp. 79-93 ◽  
Author(s):  
Jack L. Krogstad ◽  
Mark H. Taylor ◽  
Maribeth J. Stock
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Lower Bound ◽  
Financial Statements ◽  
Law Students ◽  
Potential Loss

This experimental study investigates the efficacy of lawyers' letters in providing auditors with corroborating evidence about litigation contingencies. Fifty second- and third-year law students indicate their willingness to provide auditors with estimates of the likelihoods of unfavorable outcomes and potential damages for two realistic litigation cases. The findings indicate that (1) the potential loss of attorney-client privilege and (2) likelihoods of unfavorable litigation outcomes that approach auditors' lower bound for accrual both may inhibit lawyers' responses to auditors. Overall, these findings raise doubts about the efficacy of this widely utilized auditing procedure and lead to concerns about whether litigation contingencies and corresponding losses may be underreported in financial statements.

Experimental investigation on the moment-rotation performance of pultruded FRP web-flange junctions

2021 ◽  
pp. 109087
Author(s):  
Gisele G. Cintra ◽  
Daniel C.T. Cardoso ◽  
Janine D. Vieira ◽  
Thomas Keller
Keyword(s):  
Experimental Investigation ◽  
The Moment

Perceiving at a distance: enaction, exteriority and possibility – a tribute to John Stewart

2021 ◽  
pp. 105971232110310
Author(s):  
Charles Lenay
Keyword(s):  
Experimental Study ◽  
Perceptual Experience ◽  
Spatial Perception ◽  
Distant Object ◽  
New Approach ◽  
Second Stage ◽  
The Moment ◽  
Two Stages

The aim of this article is to offer a new approach of perception regarding the position of a distant object. It is also a tribute to John Stewart who accompanied the first stages of this research. Having already examined the difficulties surrounding questions of the perception of exteriority within the framework of enactive approaches, we will proceed in two stages. The first stage will consist of an attempt to explain distal perception in terms of individual sensorimotor invariants. This poses the problem but fails to solve it. The second stage will propose a new pathway to account for spatial perception; a pathway that does not deny the initial intuitions of the autopoietic enactive approaches, but one which radically changes the conception of cognition by considering, from the perceptual stage, the need to take into account interindividual interactions. The protocol of an original experimental study will characterize this new approach considering the perceptual experience of objects at a distance, in exteriority, in a space of possibilities without parting from the domain of interaction. To do this, we have to work at the limits of the perceptual crossing, that is, at the moment when the perceptual reciprocity between different subjects begins to disappear.

Experimental investigation on the shock-wave load attenuation by geometrical means

Shock Waves ◽  
2009 ◽  
Vol 20 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Shachar Berger ◽  
Oren Sadot ◽  
Gabi Ben-Dor
Keyword(s):  
Shock Wave ◽  
Experimental Investigation ◽  
Wave Load

Experimental Investigation of Microcutting Mechanisms in Marble Grinding

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
LJ. Tanovic ◽  
P. Bojanic ◽  
R. Puzovic ◽  
S. Klimenko
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Cutting Force ◽  
Surface Finish ◽  
Normal Component ◽  
Natural Material ◽  
Grinding Process ◽  
Force Component ◽  
Diamond Grain

This paper offers an experimental study of the microcutting mechanisms in marble grinding to aid the optimization of the marble grinding process. The necessity for investigating these mechanisms is dictated by the increased use of marble in many applications and the fact that grinding and polishing processes are the dominant technologies used to meet surface finish requirements in this natural material. The experiments are aimed at the determination of the normal component of the cutting force and of the grain traces in microcutting with a single diamond grain. The investigations carried out make provisions for establishing critical grain penetration and cutting depths and allow the prediction of the normal cutting force component as a function of grain penetration speed and depth.

Research on Propagation Numerical Simulation of Blast Shock Waves in Subway Station

2013 ◽  
Vol 380-384 ◽  
pp. 1725-1728
Author(s):  
Yang Hu ◽  
Huai Yu Kang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Experimental Study ◽  
Shock Waves ◽  
Theoretical Basis ◽  
Damage Effect ◽  
Subway Station ◽  
Element Calculation ◽  
Dynamic Finite Element ◽  
Walking Pattern

In this paper, we Research on Propagation Numerical Simulation and damage effect of Blast Shock Waves in Subway Station by using LS-DYNA dynamic finite element calculation program , the results reproduce the formation process of the explosive flow field, and analysis the shock wave waveform, attenuation and walking pattern, provides the theoretical basis for further experimental study.

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