Analytical buckling models are important for down-hole operations to ensure the structural integrity of the drill string. A literature survey shows that most published analytical buckling models do not address the effects of inclination angle, boundary conditions or friction. The objective of this paper is to study the effects of boundary conditions, friction and angular inclination on the heli...

We characterized the α-to-β transition in α-helical coiled-coil connectors of the human fibrin(ogen) molecule using biomolecular simulations of their forced elongation and theoretical modeling. The force (F)-extension (X) profiles show three distinct regimes: (1) the elastic regime, in which the coiled coils act as entropic springs (F < 100-125 pN; X < 7-8 nm); (2) the constant-force plastic re...

The theory of the a-helix to random coil transition in two-chain, coiled coils is extended to include the effect of loop entropy. To ascertain the conditions under which loop entropy is important, expressions are derived with the neglect of loop entropy for the ratio (R) of the number of residues that are part of randomly coiled runs at the chain ends to the total number of randomly coiled resi...

Improvements in miniaturization and boosting the thermal performance of energy conservation systems call for innovative techniques to enhance heat transfer. Heat transfer enhancement methods have attracted a great deal attention industrial sector due their ability provide savings, encourage proper use sources, increase economic efficiency systems. These are categorized into active, passive, com...

in the present study the effect of curvature ratio and coil pitch for tio2/water nanofluid laminar flow on heat transfer behavior and pressure drop through helical coils with different geometries was investigated experimentally. the tio2/water nanofluids at 0.25% to 2% particle volume concentrations have been prepared by using a two-step method. the experiments were performed for coils with cur...

Clathrin-coated vesicles were isolated from soybean (Glycine max L.) cells in suspension culture and their purity was assessed using SDS-PAGE, peptide sequencing and electron microscopy. Antibodies raised to these coated vesicles were used to immunoscreen a soybean cDNA library in lambda gt11 and isolate a partial clone of the clathrin heavy chain (HC) gene. Full-length cDNA for soybean clathri...