Search results for "VISCOSITY"
showing 10 items of 542 documents
Commercial thickeners used by patients with dysphagia: Rheological and structural behaviour in different food matrices
2015
In order to achieve a safe swallowing in patients with dysphagia, liquids must be thickened. In this work, two commercial starch based thickeners dissolved inwater,whole milk, apple juice and tomato juice were studied. The thickeners were Resource®, composed of modified maize starch and Nutilis®, composed of modified maize starch and gums. They were formulated at two different concentrations corresponding to nectar- and pudding-like consistencies. Influence of composition, concentration and food matrix on rheological properties and structure of the resulting pastes were analysed. Viscoelastic measurements and microscopic observations of the thickeners dissolved in water revealed structural …
The interaction of native DNA with iron(III)- N ,N'-ethylene-bis(salicylideneiminato)-chloride.
2004
Abstract The interaction between native calf thymus deoxyribonucleic acid (DNA) and Fe III - N , N ′ -ethylene-bis (salicylideneiminato)-chloride, Fe(Salen)Cl, was investigated in aqueous solutions by UV–visible (UV–vis) absorption, circular dichroism (CD), thermal denaturation and viscosity measurements. The results obtained from CD, UV–vis and viscosity measurements exclude DNA intercalation and can be interpreted in terms of an electrostatic binding between the Fe(Salen) + cation and the phosphate groups of DNA. The trend of the UV–vis absorption band of the Fe(Salen)Cl complex at different ratios [DNA phosphate ]/[Fe(Salen)Cl] and the large increase of the melting temperature of DNA in …
New benzothieno[3,2-d]-1,2,3-triazines with antiproliferative activity: synthesis, spectroscopic studies, and biological activity.
2014
New benzothieno[3,2-d]-1,2,3-triazines, together with precursors triazenylbenzo[b]thiophenes, were designed, synthesized and screened as anticancer agents. The structural features of these compounds prompted us to investigate their DNA binding capability through UV–vis absorption titrations, circular dichroism, and viscometry, pointing out the occurrence of groove-binding. The derivative 3-(4-methoxy-phenyl)benzothieno[3,2-d]-1,2,3-triazin-4(3H)-one showed the highest antiproliferative effect against HeLa cells and was also tested in cell cycle perturbation experiments. The obtained results assessed for the first time the anticancer activity of benzothieno[3,2-d]-1,2,3-triazine nucleus, and…
Effect of storage period under variable conditions on the chemical and physical composition and colour of Spanish refrigerated orange juices
2005
The effects of the physicochemical and quality characteristics of various minimally pasteurized refrigerated orange Spanish juices and their changes with storage time and temperature were investigated. Essential oils, acidity, conductivity, diacetyl index, hydroxymethylfurfural, formol index, viscosity and ascorbic acid varied with storage time more significantly at 10 degrees C than at 4 degrees C. Density, colour and pectinmethylesterase did not vary at 4 degrees C. Some of the parameters could be used as indicators of quality loss or spoilage of the juices. The degradation kinetics of the concentration of remaining ascorbic acid against time follows a straight line whose slope indicates …
Solutions of nonlinear PDEs in the sense of averages
2012
Abstract We characterize p-harmonic functions including p = 1 and p = ∞ by using mean value properties extending classical results of Privaloff from the linear case p = 2 to all pʼs. We describe a class of random tug-of-war games whose value functions approach p-harmonic functions as the step goes to zero for the full range 1 p ∞ .
Existence of viscosity solutions to two-phase problems for fully nonlinear equations with distributed sources
2018
In this paper we construct a viscosity solution of a two-phase free boundary problem for a class of fully nonlinear equation with distributed sources, via an adaptation of the Perron method. Our results extend those in [Caffarelli, 1988], [Wang, 2003] for the homogeneous case, and of [De Silva, Ferrari, Salsa, 2015] for divergence form operators with right hand side.
Hyperviscosity syndrome in patients with ovarian carcinoma
1998
BACKGROUND In patients with ovarian carcinoma, an hematocrit-independent hyperviscosity syndrome is often present. The syndrome is characterized by normal or low hematocrit and hemoglobin concentration, an elevated platelet count, and an increase in clotting factor turnover. Because deep vein thrombosis (DVT) often complicates the course of ovarian carcinoma, the aim of this study was to investigate the possible association of hyperviscosity syndrome with the development of DVT. METHODS Rheologic estimations of the blood included red blood cell (RBC) aggregation (stasis and low shear), plasma viscosity (pv), blood cell count, and fibrinogen, which were performed before primary surgery and t…
Surfactant Association: Recent Theoretical and Experimental Developments
1991
A theoretical model describing the association of ionic surfactants into rod-shaped micelles is combined with an approximate formula for the viscosity increase induced by rod-shaped aggregates. It is shown that most of the thermodynamic parameters of the association model can be obtained from viscosity measurements. The approach is applied to micellar solutions of hexadecylpyridinium salts. The pronounced effect of counter-ion concentration on the growth of rod-shaped micelles can be attributed to a slightly higher degree of counter-ion association in the cylindrical part than in the end portions. An attempt is made to explain the finding that the degree of counter-ion association is virtua…
Effect of kind and content of organo-modified clay on properties of PET nanocomposites
2011
In this work we report the properties of nanocomposite based on PET with two different samples of organically modified montmorillonites. In particular, we studied the effect of the filler concentration on morphology, rheology, and mechanical performance, focusing our attention on the effect of the degradation phenomena of the clay modifiers. The results indicate that at low clay level the morphology achieved is mainly intercalated. On increasing the filler level, coalescence and/or bad defragmentation phenomena induce a coarser morphology, as confirmed by XRD, SEM, and TEM observations. When a more polar organic modifier is used to modify the clay, the particle adhesion and distribution is …
Singularity formation for Prandtl’s equations
2009
Abstract We consider Prandtl’s equations for an impulsively started disk and follow the process of the formation of the singularity in the complex plane using the singularity tracking method. We classify Van Dommelen and Shen’s singularity as a cubic root singularity. We introduce a class of initial data, uniformly bounded in H 1 , which have a dipole singularity in the complex plane. These data lead to a solution blow-up whose time can be made arbitrarily short within the class. This is numerical evidence of the ill-posedness of the Prandtl equations in H 1 . The presence of a small viscosity in the streamwise direction changes the behavior of the singularities. They stabilize at a distanc…