Adhesion Force Between High Energy Surfaces in Vapor Atmosphere

1994 ◽  
Vol 366 ◽  
Author(s):  
Jerome Crassous ◽  
Jean-Luc Loubet ◽  
Elisabeth Charlaix
Keyword(s):  
Liquid Bridge ◽  
Adhesion Force ◽  
Van Der Waals ◽  
Surface Force ◽  
High Energy ◽  
Attractive Force ◽  
Experimental Measurements ◽  
Metallic Substrates ◽  
Energy Surfaces ◽  
Good Agreement

ABSTRACTWe report experimental measurements of the adhesion force between metallic substrates in undersaturated heptane vapor atmosphere, with a surface force apparatus. The attractive force between the substrates is strongly dependant of the condensation of a liquid bridge connecting the surfaces. The results show the importance of wetting phenomena for the maximum attractive force: we find that this maximum attraction varies as the power two-third of the curvature of the meniscus connecting the surfaces, in good agreement with the theory of Van der Waals wetting.

scholarly journals Modeling and Measurement of Thermal Effect in a Flashlamp-Pumped Direct-Liquid-Cooled Split-Disk Nd:LuAG Ceramic Laser Amplifier

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Shengzhe Ji ◽  
Wenfa Huang ◽  
Tao Feng ◽  
Long Pan ◽  
Jiangfeng Wang ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Thermal Effects ◽  
Thermal Deformation ◽  
High Energy ◽  
Gain Medium ◽  
Wavefront Aberration ◽  
Experimental Measurements ◽  
Laser Amplifier ◽  
Design And Optimization ◽  
Ceramic Laser

In this paper, a model to predict the thermal effects in a flashlamp-pumped direct-liquid-cooled split-disk Nd:LuAG ceramic laser amplifier has been presented. In addition to pumping distribution, the model calculates thermal-induced wavefront aberration as a function of temperature, thermal stress and thermal deformation in the gain medium. Experimental measurements are carried out to assess the accuracy of the model. We expect that this study will assist in the design and optimization of high-energy lasers operated at repetition rate.

scholarly journals Interaction and Adsorption of Hydrophobically Modified Polyacrylamide on Silica and Asphaltene Surfaces

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Wenjie Zou ◽  
Zichuan Fang ◽  
Zhijun Zhang ◽  
Zhenzhen Lu
Keyword(s):  
Oil Recovery ◽  
Adhesion Force ◽  
Interaction Mechanism ◽  
Surface Force ◽  
Industrial Applications ◽  
Oil Sand ◽  
Continuous Adsorption ◽  
Hydrophobically Modified Polyacrylamide ◽  
Hydrophobically Modified ◽  
Modified Polyacrylamide

The adsorption of polymers affects the cost and oil recovery in oil reservoir exploitation and the flocculation effect in the treatment of oil sand tailings. The adhesion and adsorption of a hydrophobically modified polyacrylamide (HMPAM), i.e., P(AM-NaAA-C16DMAAC), on silica and asphaltene were investigated using surface force measurements, thermodynamic analysis and quartz crystal microbalance with dissipation (QCM-D) measurement. Our study indicates that HMPAM polymer has strong interaction with both silica and asphaltene. The adhesion force of HMPAM on silica was stronger than that on asphaltene surface. Consistently, the adsorption of HMPAM was also greater on silica surface, with a more rigid layer formed on the surface. For HMPAM/silica system, the attractive interaction and the strong adhesion are mainly driven by the hydrogen bonding and electrostatic interaction. For HMPAM/asphaltene system, it is mainly due to hydrophobic interaction between the long hydrocarbon chains of HMPAM and asphaltene. Furthermore, continuous adsorption of HMPAM was detected and multiple layers formed on both silica and asphaltene surfaces, which can be attributed to the hydrophobic chains of HMPAM polymers. This work has illustrated the interaction mechanism of HMPAM polymer on hydrophilic silica and hydrophobic asphaltene surfaces, which provide insight into the industrial applications of hydrophobically modified polymer.

The Behaviour of Multiple Loops in Torsion

1988 ◽  
Vol 15 (3) ◽  
pp. 149-156 ◽  
Author(s):  
R. A. Cavina ◽  
N. E. Waters
Keyword(s):  
Energy Method ◽  
Strain Energy ◽  
Vertical Axis ◽  
Experimental Measurements ◽  
Complementary Strain ◽  
Radial Axis ◽  
Strain Energy Method ◽  
Good Agreement

The angular stiffness of a multiple looped span, subject to rotation about a vertical axis (torsion) and also to rotation about a horizontal or radial axis (mesio-distal tilt), have been derived using the complementary (strain) energy method. Experimental measurements on enlarged models were in good agreement with the values calculated from the theoretical relationships obtained. The variations in angular stiffness resulting from changes in the loop height, width, and position of clinical sized loops are discussed.

Condensation energies for metals on glass and other substrates

1959 ◽  
Vol 252 (1270) ◽  
pp. 418-430 ◽  
Keyword(s):  
Sodium Chloride ◽  
Single Crystal ◽  
Physical Adsorption ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Potassium Bromide ◽  
Binding Energies ◽  
Adhesive Energy ◽  
Good Agreement

Earlier work on condensation phenomena is briefly reviewed, and existing measurements of condensation energies are summarized. Measurements of condensation energies have been made for aluminium, silver and cadmium on glass and for aluminium and silver on single-crystal cleavage surfaces of sodium chloride and potassium bromide. Adhesive energies or binding energies between film and substrate have been calculated in each case. Association energies for nucleation are obtained by difference and shown to be consistent. Results for cadmium show good agreement with earlier work, but results for aluminium do not agree with the earlier results of Rhodin who measured the condensation energies for aluminium on various substrates, obtaining values which suggest chemisorption. These results appear to be too high and a possible explanation is given. It is concluded that the adhesive energy is due to physical adsorption and can be explained in terms of van der Waals forces only.

ELECTRONIC STRUCTURE AND OPTICAL PROPERTIES OF CRYSTALLINE C60

1992 ◽  
Vol 06 (06) ◽  
pp. 309-321 ◽  
Author(s):  
W.Y. CHING ◽  
MING-ZHU HUANG ◽  
YONG-NIAN XU ◽  
FANQI GAN
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Optical Spectrum ◽  
Local Density ◽  
Low Dielectric Constant ◽  
Experimental Measurements ◽  
Absorption Bands ◽  
Low Dielectric ◽  
Good Agreement

The electronic structure and optical properties of crystalline C 60 and their pressure dependence have been studied by first-principles local density calculations. It is shown that fcc C 60 has a low dielectric constant and an optical spectrum rich in structures. The spectrum shows five disconnected absorption bands in the 1.4 to 7.0 eV region with sharp structures in each band that can be attributed to critical point transitions. This is a manifestation of the localized molecular structure coupled with long range crystalline order unique to the C 60 crystal. At a sufficient high pressure, the structures in the optical spectrum start to merge due to the merging of the bands. These results are in good agreement with some recent experimental measurements.

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