Effect of Surface Pressure on the Insulator to Metal Transition of a Langmuir Polyaniline Monolayer

2003 ◽  
Vol 125 (31) ◽  
pp. 9312-9313 ◽  
Author(s):  
Jie Zhang ◽  
Anna L. Barker ◽  
Daniel Mandler ◽  
Patrick R. Unwin
Keyword(s):  
Surface Pressure ◽  
Effect Of Surface

The effect of surface pressure modification on the speed of vortex rings

2014 ◽  
Vol 46 (5) ◽  
pp. 055503
Author(s):  
Matthew Partridge ◽  
Frank Davis ◽  
Stephen W James ◽  
Ralph P Tatam ◽  
Seamus P J Higson
Keyword(s):  
Surface Pressure ◽  
Vortex Rings ◽  
Effect Of Surface

Atmospheric Pressure Changes: The Importance of Deviations from the Balanced (Gradient) Wind

1948 ◽  
Vol 1 (1) ◽  
pp. 41
Author(s):  
CHB Priestley
Keyword(s):  
Surface Pressure ◽  
Pressure Rise ◽  
Vertical Motion ◽  
Surface Friction ◽  
Pressure System ◽  
Gradient Wind ◽  
Horizontal Acceleration ◽  
Cold Pools ◽  
Pressure Changes ◽  
Effect Of Surface

The paper comprises a discussion of the effect of deviations from the instantaneously balanced, or gradient, wind on the translation and development of the surface pressure field. The deviation is shown to consist primarily of two components, which are associated respectively with vertical motion and horizontal acceleration in the air trajectory. With certain types of pressure system, the first of the above components makes a contribution towards translation of the system. But its major role is in maintenance of the system against the dissipating effect of surface friction. The part played by this component in the intensification of anticyclones, end the formation of secondary depressions and cold pools is discussed : in particular, these common types of development are linked with vertical motion at the tropopause and in the stratosphere. The level just below the tropopause is shown to be crucial in the study of anticyclogenesis. The collapse of an anticyclone under excessive surface heating, the formation of "heat lows", and the pressure rise associated with convectional squalls are also attributed to this deviation. By means of the deviation associated with horizontal acceleration, the changes in pressure force experienced by a moving element give rise to compensating flows which restrict any rapid local changes in surface pressure. In conjunction with the control exercised by the balanced wind(l), this accounts for the remarkable conservatism of surface pressure in face of the large convergence or divergence which atmospheriic motion appears to imply. Apart from its controlling influence, the contribution from the horizontal acceleration increases with increasing asymmetry of the system. The eastward thrust of sharp ridges of high pressure is attributable to this deviation.

Effect of Contact Area on Friction Force in Sheet Metal Forming Operations

2018 ◽  
Vol 767 ◽  
pp. 77-84 ◽  
Author(s):  
Ali Mousavi ◽  
Theresa Sperk ◽  
Tobias Gietzelt ◽  
Tim Kunze ◽  
Andrés Fabián Lasagni ◽  
...  
Keyword(s):  
Friction Force ◽  
Surface Pressure ◽  
Contact Area ◽  
Surface Texturing ◽  
Forming Process ◽  
Friction Forces ◽  
Pressure Surface ◽  
Draw Bending ◽  
Forming Tools ◽  
Effect Of Surface

There are a number of ways to reduce friction such as lubrication, improving the surface roughness, reducing the acting surface pressure, surface texturing and reducing the contact area. In this study the effect of the contact size and surface pressure on process limits of a forming process is investigated. For this purpose draw-bending of U-Channel is subjected for testing of the effect of surface reduction by means of micro surface texturing and macro structuring. The results show that micro surface texturing and macro structuring of forming tools can reduce the friction force in forming processes. A combination of these approaches can be applied in tooling design to minimize the friction forces and ultimately realize a lubricant-free forming process.

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