The Physics of Metallic Superlattices: An Experimental Point of View

1988 ◽  
pp. 139-169 ◽  
Author(s):  
Ivan K. Schuller
Keyword(s):  
Point Of View ◽  
Experimental Point

High-Tc superconductors from the experimental point of view

1988 ◽  
Vol 156 (9) ◽  
pp. 117-135 ◽  
Author(s):  
L.P. Gor'kov ◽  
N.B. Kopnin
Keyword(s):  
Point Of View ◽  
Experimental Point

Characterization of Tilt Boundaries by Ultra High Resolution Electron Microscopy

1984 ◽  
Vol 41 ◽  
Author(s):  
W. Krakow ◽  
J. T. Wetzel ◽  
D. A. Smith ◽  
G. Trafas
Keyword(s):  
High Resolution ◽  
Grain Boundary ◽  
Structural Information ◽  
Theoretical Work ◽  
High Resolution Electron Microscopy ◽  
Point Of View ◽  
Experimental Point ◽  
Structure Information ◽  
Resolution Electron ◽  
Tilt Boundaries

AbstractA high resolution electron microscope study of grain boundary structures in Au thin films has been undertaken from both a theoretical and experimental point of view. The criteria necessary to interpret images of tilt boundaries at the atomic level, which include electron optical and specimen effects, have been considered for both 200kV and the newer 400kV medium voltage microscopes. So far, the theoretical work has concentrated on two different [001] tilt bounda-ries where a resolution of 2.03Å is required to visualize bulk lattice structures on either side of the interface. Both a high angle boundary, (210) σ=5, and a low angle boundary, (910) σ=41, have been considered. Computational results using multislice dynamical diffraction and image simulations of relaxed bounda-ries viewed edge-on and with small amounts of beam and/or specimen inclina-tion have been obtained. It will be shown that some structural information concerning grain boundary dislocations can be observed at 200kV. However, many difficulties occur in the exact identification of the interface structure viewed experimentally for both [001] and [011] boundaries since the resolution required is near the performance limit of a 200kV microscope. The simulated results at 400kV indicate a considerable improvement will be realized in obtain-ing atomic structure information at the interface.

Determination of In-plane Shear Strength of Unidirectional Composite Materials Using the Off-axis Three-point Flexure and Off-axis Tensile Tests

2010 ◽  
Vol 44 (21) ◽  
pp. 2487-2507 ◽  
Author(s):  
G. Vargas ◽  
F. Mujika
Keyword(s):  
Shear Strength ◽  
Composite Materials ◽  
Tensile Tests ◽  
Unidirectional Composite ◽  
Point Of View ◽  
Experimental Point ◽  
Plane Shear ◽  
Lift Off ◽  
Flexure Test

The aim of this work is to compare from an experimental point of view the determination of in-plane shear strength of unidirectional composite materials by means of two off-axis tests: three-point flexure and tensile. In the case of the off-axis three-point flexure test, the condition of small displacements and the condition of lift-off between the specimen and the fixture supports have been taken into account. Some considerations regarding stress and displacement fields are presented. The in-plane shear characterization has been performed on a carbon fiber reinforced unidirectional laminate with several fiber orientation angles: 10°, 20°, 30°, and 45°. Test conditions for both off-axis experimental methods, in order to ensure their applicability, are presented. Off-axis flexure test is considered more suitable than off-axis tensile test for the determination of in-plane shear strength.

scholarly journals Effect of Solvent Refractive Index on the Surface Plasmon Resonance Nanoparticle Optical Absorption

2007 ◽  
Vol 7 (12) ◽  
pp. 4333-4338
Author(s):  
Gulay Ertas ◽  
Sefik Suzer
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Surface Plasmon ◽  
Surrounding Medium ◽  
Point Of View ◽  
Experimental Point ◽  
Absorption Bands ◽  
Plasmon Band ◽  
Silver And Gold Nanoparticles ◽  
Band Position

Optical properties of plasmon coupled silver and gold nanoparticles were studied as a function of the refractive index of the surrounding medium. Our studies confirmed that the effect of changes in the refractive index of the surrounding medium was more difficult to demonstrate from an experimental point of view, because of the very high susceptibility of nanoparticles to aggregate in aqueous and organic solvents. Whereas the position of the absorption bands of triiodide in these solvents shows a clear dependence on medium's refractive index, the surface plasmon band position of silver and gold nanoparticles do not exhibit the same dependence. This is attributed to a non-negligible interaction of these solvents with nanoparticle surfaces.

scholarly journals Aging of the Geiger-Muller counter due to particle conductance in an insulating gas

2017 ◽  
Vol 32 (3) ◽  
pp. 250-255 ◽  
Author(s):  
Dalibor Arbutina ◽  
Tomislav Stojic ◽  
Aleksandra Vasic-Milovanovic ◽  
Uros Kovacevic ◽  
Dragan Brajovic
Keyword(s):  
Working Conditions ◽  
Aging Effect ◽  
Point Of View ◽  
Experimental Point ◽  
Experimental Part ◽  
Geiger Muller Counter ◽  
Chamber Model ◽  
Law Of Similarity ◽  
Aging Phenomena ◽  
Conductive Particles

In this paper, the aging effect of commercially available Geiger-Muller counters under working conditions is being considered from both theoretical and experimental point of view. In the experimental part lifetime curves for the commercial Geiger-Muller counter chamber are first recorded. After detection of the aging phenomena, the commercial chamber response to an impulse voltage is tested along with recording of the same response of the Geiger-Muller chamber model with conductive particles included. The law of similarity for the gaseous discharge is fulfilled both by the commercial Geiger-Muller chamber and by the chamber model with conductive particles. The results obtained from the U-test indicate that the aging of the Geiger-Muller chamber is mainly caused by the occurrence of a great number of conductive particles hovering inside the chamber. Some suggestions of how to reduce the aging effect due to conductive particles inside the Geiger-Muller chamber are given in the conclusion.

scholarly journals Bending Response and Energy Absorption of Closed-Hat-Section Beams

2016 ◽  
Vol 10 (11) ◽  
pp. 225
Author(s):  
Hafizan Hashim ◽  
Amir Radzi Ab Ghani ◽  
Wahyu Kuntjoro
Keyword(s):  
Energy Absorption ◽  
Plate Thickness ◽  
Point Of View ◽  
Critical Parameters ◽  
Research Report ◽  
Experimental Point ◽  
Fe Model ◽  
Research Information ◽  
Foam Filling ◽  
Energy Absorbers

Many articles on bending collapse but not limited to closed-hat-section beams have been reported mainly from experimental point of view but less in simulation-based approach. Detailed investigation on critical parameters of closed-hat-section beams to examine their energy absorption capability is also less found in the literature. This paper presents the procedure for development and validation of a finite element (FE) model of a closed-hat-section beam under quasi static three-point bending using an explicit nonlinear FE technique. Developed FE models were validated through comparison with existing and present experiment results. Firstly, the existing models were rebulit via present modeling technique using informations provided in the relevant research report. Simulation results of rebuilt model were compared with existing results for verification and validation. Next, to further validate the present model, actual physical experiment replicating the FE model was set up for comparison of results. Validated models were then used in parametric studies in order to investigate the effect of some critical parameters such as plate thickness, flange and web width, and foam filler. Results show that the wall thickness, web width, and filler have direct effect on bending stiffness. Foam filling indicated significant enhancement on the crush and energy absorption of closed-hat-section beams. This study provides detail procedures and research information which will facilitate improvisation of current design as well as the design of foam filled closed-hat-section beams as energy absorbers in impact applications.

scholarly journals II. On the principal electric time-constant of a circular disk

1887 ◽  
Vol 42 (251-257) ◽  
pp. 289-296 ◽  
Keyword(s):  
Time Constant ◽  
Infinite Series ◽  
Circular Disk ◽  
Point Of View ◽  
Experimental Point ◽  
Normal Type ◽  
Time Constants ◽  
The One ◽  
Original Strength ◽  
Different Parts

The time-constant for currents of any normal type in a given conductor is the time in which free currents of that type fall to 1/ e of their original strength. In strictness there are for any conductor an infinite series of time-constants, corresponding to the various normal types, but in such a case as that of a coil of wire one of these is very great in comparison with the rest, which belong to types in which the current is in opposite directions in different parts of a section of the wire. And in all cases the time-constant corresponding to the most persistent type which can be present under given circumstances is, of course, the one which is most important from an experimental point of view.

Monitoring of a controlled space flexible multibody by means of embedded piezoelectric sensors and cameras synergy

2018 ◽  
Vol 29 (14) ◽  
pp. 2966-2978 ◽  
Author(s):  
Matteo Ribet ◽  
Marco Sabatini ◽  
Luca Lampani ◽  
Paolo Gasbarri
Keyword(s):  
Optical Sensors ◽  
Attitude Control ◽  
Point Of View ◽  
Vibration Monitoring ◽  
Structural Vibration ◽  
Elastic Displacement ◽  
Experimental Point ◽  
Solar Panels ◽  
Flexible Multibody ◽  
Usual Solution

Interaction between elastic dynamics and attitude control is a serious problem in space operations, which often involve satellites with highly flexible appendages. Monitoring and eventually control of the vibrations are a major concern to avoid a decrease in the expected performance. In particular, the classic case of a central bus with two lateral appendages (solar panels) is considered. The design of a system for structural vibration monitoring is proposed both from a numerical and an experimental point of view. Piezoelectric devices are a usual solution for measuring the deformation of the structures. In the proposed work, optical sensors are also implemented: the combined use of the two sets allows for the monitoring of the elastic displacement of the solar panels and for the reconstruction of the modal shapes of the entire flexible multibody system.

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