A petroleum fluid can be di®ided into three types of species: asphaltenes, resins, and oils. Asphaltenes and resins are polar, while the rest of the so-called oils are either nonpolar or mildly polar. The interaction among these species strongly affect asphaltene precipitation from petroleum fluids. Different measuring methods for asphaltenes in a petroleum fluid gi®e similar results, but diffe...

The liquid-vapor interfacial tension of various simple, polar, and ionic fluids is studied in a corresponding-states analysis originally suggested by Guggenheim [1]. The results for real fluids are compared to the corresponding ones for model fluids of each of the three types. For simple and weakly polar fluids, the data is mapped onto a master curve, as already demonstrated by Guggenheim. For ...

BACKGROUND The FloTrac/Vigileo™ system does not thoroughly reflect variable arterial tones, due to a lack of external calibration. The ability of this system to measure stroke volume and track its changes after fluid administration has not been fully evaluated in patients with the high systemic vascular resistance that can develop during laparoscopic surgery. METHODS In 42 patients undergoing...

We consider the hydrodynamic theory of an active fluid of self-propelled particles with nematic aligning interactions. This class of materials has polar symmetry at the microscopic level, but forms macrostates of nematic symmetry. We highlight three key features of the dynamics. First, as in polar active fluids, the control parameter for the order-disorder transition, namely the density, is dyn...

Ripple phase modelling was achievable by taking into consideration the dipole structure of the polar heads of model membrane molecules. Computer simulations enabled the selective analysis of a model membrane. Considering only the hydrophobic part of the lipid membrane, the gel-fluid transition stage can be obtained in such a simulation. Assuming an additional degree of freedom, the entire molec...