Wyniki wyszukiwania - BazTech

1

Acustical studies of interactions in the binary mixtures of ethylmethyl ketone (EMK) and N,N-dimethylformamide (DMF) through ultrasonic measurements at different temperatures

Patial B. S.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 47

120--132

EN

Ultrasonic velocities (u), densities (ρ) and viscosities (η) are measured in respect of ethylmethylketone (EMK) and N,N-dimethylformamide (DMF) over the entire composition at 298, 308and 318K. Attempt have been made to extract the information with respect to various kind of intermolecular interactions, such as H-bonding, dipole-dipole, solute –solvent, dispersion type interactions existing between these two components from the following acoustical parameter when examined as a function of solvent composition at different temperatures: adiabatic compressibility (β), specific acoustic impedance (Z), intermolecular free length (Lf), molar sound velocity (Rm), wada’s constant (W), viscous relaxation time (τ), free volume and internal pressure (πi).

2

Volumetric, Viscometric, and Refractive Index Studies of Some alfa-Amino Acids in Aqueous Tartrazine at Different Temperatures

Ali A., Patel R., Shahjahan, Tasneem S.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 7

1353-1363

EN

The densities (r), viscosities (h), and refractive indices (nD) of (0.10, 0.15, 0.20, 0.25, and 0.30) m glycine, L-alanine, and L-valine were measured in 0.01 m aqueous tartrazine at 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15 K. The measured data were utilized to evaluate various use ful parame ters, viz., apparent molar volume, (fi ni ), partial molar volume, (fi ni o), partial molar isobaric expansibility, (fi i E o ), transfer volume (fi ni o (tr)), A and B – coefficients of viscosity, free energy of activation of viscous flow per mole of solvent (Delta mi 1 o*) and solute (Delta mi 2o*) and molar refractivity (RD). The linear varia ion of fi ni o with the number of carbon atoms (nC) present in the alkyl chain of amino acids was also considered for the evaluation of the contribution of zwitterionic end groups (NH3 + , COO–) and methylene groups to fi ni o. The results were used to discussion–ion, ion–nonpolar and nonpolar–nonpolar interactions and the presence of structural hydration in the present systems.

3

Laminar micromixing of liquids of equal and unequal viscosities. The role of characteristic time scales of the process

Rożeń A., Bałdyga J.

Inżynieria Chemiczna i Procesowa

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2006

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T. 27, z. 2

335-347

EN

Micromixing of liquids of equal and unequal viscosities has been studied in a simple linear flow field. Influence of viscosity difference on time evolution of a new intermaterial surface area was determined. Micromixing model was applied to identify ranges of characteristic time scales of deformation, molecular diffusion and chemical reaction for which viscosity may affect most the reaction time and the selectivity of a system of competitive-parallel reactions.

PL

Zbadano mikromieszanie cieczy o jednakowej i różnej lepkości w prostym liniowym polu przepływu. Określono wpływ różnic lepkości na proces tworzenia się nowej powierzchni kontaktu między cieczami. Użyto modelu mikromieszania do zidentyfikowania zakresu charakterystycznych skal czasowych deformacji, dyfuzji molekularnej i reakcji chemicznej, dla których różnice lepkości mogą najbardziej wpływać na czas reakcji i selektywność układu reakcji równoległych i konkurencyjnych.

4

Comparison of power-consumption characteristics based on water properties and real properties of a cereal coffee extract produced in a mixer

Wesołowski P.

Inżynieria Chemiczna i Procesowa

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2006

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T. 27, z. 2

463-474

EN

The results of comparison of mixing characteristics of a system solid.liquid based on physical parameters of a liquid with these based on real densities and viscosities of suspensions studied, have been presented. An analysis was carried out for the suspending of the cereal coffee into water using the paddle impellers pumping up and pumping down.

PL

Przedstawiono wyniki analizy porównawczej charakterystyk mocy mieszania wyznaczonych na podstawie parametrów fizycznych cieczy z odpowiednimi charakterystykami wyznaczonymi dla rzeczywistych gęstości i lepkości zawiesin ciała stałego w cieczy na przykładzie wytwarzania koncentratów rozpuszczalnej kawy zbożowej z wykorzystaniem mieszadeł łapowych pompujących w górę i w dół.