The Contact and Sliding Friction of Cellular Materials

Author(s):  
M. A. Fortes ◽  
M. Fátima Vaz ◽  
S. Coughlan
Author(s):  
Jeffrey P. Chang ◽  
Jaang J. Wang

Flat embeddment of certain specimens for electron microscopy is necessary for three classes of biological materials: namely monolayer cells, tissue sections of paraffin or plastics, as well as cell concentrations, exfoliated cells, and cell smears. The present report concerns a flat-embedding technique which can be applied to all these three classes of materials and which is a modified and improved version of Chang's original methodology.Preparation of coverglasses and microslides. Chemically cleaned coverglasses, 11 × 22 mm or other sizes, are laid in rows on black paper. Ink-mark one coner for identifying the spray-side of the glass for growing cells. Lightly spray with Teflon monomer (Heddy/Contact Inductries, Paterson, NO 07524, U.S.A.) from a pressurized can. Bake the sprayed glasses at 500°F for 45 min on Cover-Glass Ceramic Racks (A. Thomas Co. Philadelphia), for Teflon to polymerize.Monolayer Cells. After sterilization, the Teflon-treated coverglasses, with cells attached, are treated or fixed in situ in Columbia staining dishes (A. Thomas Co., Philadelphia) for subsequent processing.


2006 ◽  
Vol 34 (4) ◽  
pp. 237-255 ◽  
Author(s):  
M. Kuwajima ◽  
M. Koishi ◽  
J. Sugimura

Abstract This paper describes experimental and analytical studies of the dependence of tire friction on the surface roughness of pavement. Abrasive papers were adopted as representative of the microscopic surface roughness of pavement surfaces. The rolling∕sliding friction of tire tread rubber against these abrasive papers were measured at low slip velocities. Experimental results indicated that rolling∕sliding frictional characteristics depended on the surface roughness. In order to examine the interfacial phenomena between rubber and the abrasive papers, real contact length, partial slip, and apparent friction coefficient under vertical load and tangential force were analyzed with two-dimensional explicit finite element analysis in which slip-velocity-dependent frictional coefficients were considered. Finite element method results indicated that the sum of real contact area and local partial slip were larger for finer surfaces under the same normal and tangential forces. In addition, the velocity-dependent friction enhanced local slip, where the dependence of local slip on surface roughness was pronounced. It proved that rolling∕sliding friction at low slip ratio was affected by local frictional behavior at microslip regions at asperity contacts.


Alloy Digest ◽  
2003 ◽  
Vol 52 (10) ◽  

Abstract Kaiser Aluminum alloy 4026 has high strength and good wear resistance, as well as galling resistance. It was developed for sliding friction resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on heat treating. Filing Code: AL-385. Producer or source: Tennalum, A Division of Kaiser Aluminum.


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