Search results for "Lubrication"
showing 4 items of 24 documents
Polymer brushes under flow and in other out-of-equilibrium conditions
2011
Polymer brushes are formed from flexible linear macromolecules tethered at one chain end to a solid substrate, forming a dense polymeric layer of polymer chains which are more or less stretched in the direction perpendicular to the substrate surface. These systems find interest also due to numerous applications (colloid stabilization, improvement of lubrication properties when the surfaces are exposed to shear, protection of the surface against adsorption of nanoparticles or proteins, etc.), for which often the dynamic non-equilibrium response of these brushes to external perturbation is important. The present review summarizes recent computer simulation studies pertinent to these questions…
On the tribology and rheology of polymer brushes in good solvent conditions: a molecular dynamics study
2003
Tribological and rheological properties of two polymer brushes in relative sliding motion and good solvent conditions are investigated by means of molecular dynamics (MD) simulations. The lateral forces between the brushes are found to decrease logarithmically with increasing relative sliding velocity v0 over a range of more than one decade in v0. We also observe an almost logarithmic relaxation of the end-to-end distance vector that occurs after sliding is stopped. The coincidence of these logarithmic dependencies support the picture that friction between polymer brushes is small due to the retraction of the polymers from the interpenetration zone. The shear stress relaxes almost instantly…
Sexual Dysfunctions and Their Association with the Dual Control Model of Sexual Response in Men and Women with High-Functioning Autism
2019
Adults with an Autism Spectrum Disorder (ASD) are characterized by impairments in social interaction and communication, repetitive and stereotyped interests and behaviours as well as hyper- and/or hyposensitivities. These disorder specific symptoms could be associated with the development of sexual disorders. The Dual Control Model of Sexual Response presents one approach that is frequently used to explain the emergence of sexual dysfunctions. The aim of the present study was to assess the extent of symptoms of sexual dysfunctions in men and women with ASD and to evaluate their association with the individual propensity of sexual excitation and inhibition as defined by the Dual Control Mode…
Numerical and Experimental Study of Friction Loss in Hydrostatic Motor
2012
Published version of an article in the journal: Modeling, Identification and Control. Also available from the publisher at: http://dx.doi.org/10.4173/mic.2012.3.2 Open access This paper presents a numerical and experimental study of the losses in a hydrostatic motor principle. The motor is designed so that the structural deflections and lubricating regimes between moving surfaces and, subsequently, the leakage and friction losses, can be controlled during operation. This is done by means of additional pressure volumes that influence the stator deflection. These pressures are referred to as compensation pressures and the main emphasis is on friction or torque loss modeling of the motor as a …