Collision of a comet with Jupiter: Determination of fragment penetration depths from the molecular spectra

JETP Letters ◽  
1996 ◽  
Vol 63 (6) ◽  
pp. 405-410 ◽  
Author(s):  
A. A. Berezhnoi ◽  
V. V. Shevchenko ◽  
B. A. Klumov ◽  
V. E. Fortov
Keyword(s):  
Molecular Spectra ◽  
Penetration Depths

The AC-Indentation Technique and its Application to Al and Al-Si Coatings

1991 ◽  
Vol 226 ◽  
Author(s):  
T.W. Wu
Keyword(s):  
Penetration Depth ◽  
High Sensitivity ◽  
Small Displacement ◽  
Depth Profiles ◽  
Indentation Technique ◽  
Indentation Process ◽  
Microindentation Technique ◽  
Penetration Depths ◽  
Selection Of

AbstractAn ac-microindentation technique, namely indenting with a small displacement modulation superimposed on an otherwise linear indenter motion, will be introduced. The basic principle and theory will also be illustrated by using a mechanical model to simulate the indenter behavior.Other than being as capable as conventional indentation, the ac-technique acquires the unloading slope simultaneously and continuously with the penetration depth and applied load during an entire indentation process. With this extra information, the conversion between the total depth and plastic depth can be executed right after a single indentation, and in turn the hardness as well as. contact modulus depth profiles can be calculated. This is in contrast to the conventional indentation technique where a group of indentations associated with different maximum loads are required in order to achieve the same purpose. Furthermore, it also avoids the subjectivity in the selection of the fitting portions from the unloading stage of an indentation curve to extract the unloading slopes as well as the plastic penetration depths.Another important advantage of using this ac-technique is the high sensitivity in detecting the indenter/surface contact. This advantage is very useful in the determination of the origins of penetration depths as well as in the investigation the evolution of the contact area, and both issues are very crucial in the microhardness calculations.The strain rate effect on the hardness measurements of a 1 μm thick Al-2%Si coating has been demonstrated by using the ac-technique. As the indenter loading speed increases from 2.5 to 10 nm/sec, the measured hardness of the coating can be increased from ∼20% to ∼80% depending on the penetration depth, and the shallower the penetration depth the larger the increment is. However, the contact modulus depth profiles remain unchanged for all the indentation rates.

Generation and Determination of Compressive Residual Stresses of Short Penetration Depths

2013 ◽  
Vol 768-769 ◽  
pp. 580-586 ◽  
Author(s):  
Regina Weingärtner ◽  
Jürgen Hoffmeister ◽  
Volker Schulze
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Fatigue Limit ◽  
Electrochemical Machining ◽  
Beneficial Effects ◽  
Integral Width ◽  
High Gradients ◽  
Stress States ◽  
Penetration Depths

Generating compressive residual stress states with high gradients and low penetration depths offers high capability regarding increase of fatigue limit of parts. In this work the determination of such specific residual stress distributions by using X-ray diffraction and a little material removal is introduced. Measurements are compared using two interference peaks of different penetration depths, at which confocal microscopy enables high accuracy in determination of the step sizes in electrochemical machining. Furthermore the realisation of these states by two different peening processes using micro blasting media is described. The suitability of the processes micro peening and ultrasonic wet peening as surface treatment methods to improve fatigue limit are shown. Micro peening is based on the shot peening principle with small shots and ultrasonic wet peening on the acceleration of small blasting particles by cavitation. The investigations were conducted at AISI 4140 in a quenched and tempered state. Besides the residual stresses and the integral width of interference peaks as well as the depth distributions, the surface topography was examined. The beneficial effects of these conditions on the fatigue limit in bending tests are described.

A Method for Determination of Particle Penetration Depths in a Filter

Nature ◽  
1958 ◽  
Vol 182 (4647) ◽  
pp. 1437-1438 ◽  
Author(s):  
JAN SISEFSKY
Keyword(s):  
Particle Penetration ◽  
Penetration Depths

A linear log d – log w model for the determination of consistency limits of soils

2001 ◽  
Vol 38 (6) ◽  
pp. 1335-1342 ◽  
Author(s):  
Tao-Wei Feng
Keyword(s):  
Water Content ◽  
Penetration Depth ◽  
Flow Curve ◽  
Linear Regression Analysis ◽  
Liquid Limit ◽  
Plastic Limit ◽  
Cone Penetration ◽  
Data Points ◽  
Penetration Depths

A linear logarithm–logarithm model for the fall cone penetration depth versus water content relationship (flow curve) has been developed based on the results of an experimental study using the British fall cone apparatus. The fall cone flow curve is expressed by a simple equation with parameters m and c, which represent the slope of the flow curve and the water content at a penetration depth of 1 mm, respectively. For a soil, the flow curve can be determined by applying a linear regression analysis to at least four data points with penetration depths approximately evenly distributed between 25 and 3 mm. It is shown in this paper that both the liquid limit and the plastic limit determined from the linear logarithm–logarithm flow curve are in close agreement with those determined from conventional methods. A one-point method for determination of the liquid limit is developed from the model and is verified by applying statistical analysis to a large volume of experimental data.Key words: fall cone, laboratory tests, consistency limits, clays.

Temperature dependence of rf and microwave absorption in granular HTSC-determination of Josephson and grain penetration depths

1998 ◽  
Vol 106 (4) ◽  
pp. 203-206
Author(s):  
P.V Patanjali ◽  
V Seshu Bai ◽  
R Pinto ◽  
M.D Sastry ◽  
R Vijayaraghavan
Keyword(s):  
Temperature Dependence ◽  
Microwave Absorption ◽  
Penetration Depths

scholarly journals Determination of wear of surfaces by scratch testing

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Witold Brostow ◽  
Gowrisankar Darmarla ◽  
Juliet Howe ◽  
Dorota Pietkiewicz
Keyword(s):  
Solid Material ◽  
Mechanical Tests ◽  
Solid Surfaces ◽  
Scratch Testing ◽  
Definition Of ◽  
Quantitative Definition ◽  
Scratch Tests ◽  
Penetration Depths ◽  
Indenter Geometry

Abstract We have formulated a quantitative definition of wear different from the current imprecise definitions. Wear is defined as the unwanted loss of solid material from solid surfaces due to mechanical interaction. The debris method currently used to quantify wear produces results strongly dependent on conditions. We have performed multiple scratch tests for a variety of polymer samples: polypropylene, polytetrafluoroethylene and a polyester. In each of the materials studied, the scratch penetration depths reach a constant value at a given force after 8 scratches or so. Similarly, the scratch recovery (final, healing) depths for a fixed force reach a plateau after a dozen or so scratch tests. Thus, strain hardening by repetitive scratching takes place. A likely explanation is formation of a more ordered phase - as seen before in mechanical tests by Siegmann, Aharoni, Faitelson et al. Given these results we define a measure of wear W(F) for a given indenter geometry and force F as W(F) = limn→∞ Rh(F) where n is the number of tests performed and Rh is the final (residual, healing) depth after viscoelastic recovery. The present results confirm also our earlier ones that scratch recovery is another useful way to characterize viscoelasticity.

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