EFFECTS OF SURFACTANTS ON THE TERMINAL VELOCITY OF PHENOL SOLUTION DROPS FALLING IN n-BUTYL ACETATE

ABSTRACT

Measurements of formation times and terminal velocities of aqueous phenol solution drops falling through a continuous phase of n-butyl acetate at 20°C are presented. The influence of two commercial surfactants, Medialan KF and Triton X-100 on the indicated parameters is also reported. A comparison is made between experimental results and predicted values from correlations available for terminal velocities and critical diameters, in the absence of surfactants.     

New 1,4‐Diaryl [1,2,3]‐Triazole Liquid Crystals Using a Click Reaction

New nonlinear compounds containing 1,4‐diaryl‐[1,2,3]‐triazole were prepared using a straightforward and efficient method for the regioselective synthesis of [1,2,3]‐triazoles. The methodology consists of a Cu(I)‐catalyzed 1,3‐dipolar cycloaddition of aryl azides to terminal arylacetylenes (click reaction). All compounds exhibited liquid‐crystalline profile.     

Implications of energy conditions on standard static space–times

In the framework of standard static space–times, we state a family of sufficient or necessary conditions for a set of physically reasonable energy and convergence conditions in relativity and related theories. We concentrate our study on questions about the sub-harmonicity of the warping function, the scalar curvature map, conformal hyperbolicity, conjugate points and the time-like diameter of this class of space–times.     

Isolated singularities of solutions to the Yamabe equation

In this paper we study the asymptotic behavior of local solutions to the Yamabe equation near an isolated singularity, when the metric is not necessarily conformally flat. We are able to prove, when the dimension is less than or equal to five, that any solution is asymptotic to a rotationally symmetric Fowler solution. We also prove refined asymptotics if deformed Fowler solutions are allowed in the expansion.     

SBS/Pani · DBSA mixture plasticized with DOP and NCLS - Effect of the plasticizers on the probability density of volume resistivity measurements

Plasticized mixtures of styrene-butadiene-styrene block copolymer (SBS) and Polyaniline (Pani) were prepared in a Haake internal mixer. Two different plasticizers were used: dioctyl phthalate (DOP) and cashew nut shell liquid (CNSL). Pani and plasticizers were characterized by FTIR and the resistive behavior of plasticized mixtures was investigated along the electrification time. It is shown that obtained experimental data are subject to deterministic dynamic fluctuations that cannot be described by single normal probability distribution functions (PDF) along the time. The PDF analysis shows that obtained PDFs must be described as sums of at least three distinct Gaussian distributions with different areas. It is also shown that the Gaussian component with larger area may provide better representation of the measured volume resistivity values.