Search results for "VISCOSITY"
showing 10 items of 542 documents
Physico-chemical and mechanical characterization of in-situ forming xyloglucan gels incorporating a growth factor to promote cartilage reconstruction
2016
Abstract The development of growth factors is very promising in the field of tissue regeneration but specifically designed formulations have to be developed in order to enable such new biological entities (NBEs). In particular, the range of therapeutic concentrations is usually very low compared to other active proteins and the confinement in the target site can be of crucial importance. In-situ forming scaffolds are very promising solutions for minimally invasive intervention in cartilage reconstruction and targeting of NBEs. In this work injectable, in-situ forming gels of a temperature responsive partially degalactosylated xyloglucan (Deg-XG) incorporating the growth factor FGF-18 are fo…
Evaluation of the Haemorheological Determinants in Coronary Heart Disease
1984
Increased blood viscosity has been described in patients with coronary artery disease (1, 2, 3, 4, 5, 6, 7, 8).
Associative behaviour of κ-carrageenan in aqueous solutions and its modification by different monovalent salts as reflected by viscometric parameters
2019
Abstract The viscometric behaviour of κ-carrageenan in aqueous solutions and in the presence of monovalent salts was investigated at 25 °C. Coil, helix or double helix conformations were induced by cooling hot κ-carrageenan solutions under appropriate ionic conditions. A new viscometric approach was used for modeling the behaviour of κ-carrageenan solutions. The intrinsic viscosity, [η], is markedly changed by the presence of different monovalent salts (NaCl, NaI and CsI). In pure water, the intrinsic viscosity amounts to 48 dL·g−1. In 0.1 M NaCl solutions (single helix state) [η] is 6.2 dL·g−1, whereas in 0.1 M NaI (double helix conformation) it is approximately twice as large. In 0.1 M Cs…
Solutions properties and solute–solvent interactions in ternary sugar–salt–water solutions
2010
International audience; Viscometric constants were used to provide information on solute-solvent interactions in ternary water-sugar-salt solutions. Comparison was made between pure water and aqueous salt solution as solvents affecting the behaviour of small carbohydrates. The determination of intrinsic viscosity was made more accurate by applying triple extrapolation of the three equations (Huggins. Kramer and Meffroy-Biget). Results obtained with this triple extrapolation method were compared to that obtained with the Jones-Dole equation usually used. The B coefficient of the Jones-Dole equation was interpreted in terms of its components (B(size)) and (B(structure)), respectively assigned…
Robust optimality of linear saturated control in uncertain linear network flows
2008
We propose a novel approach that, given a linear saturated feedback control policy, asks for the objective function that makes robust optimal such a policy. The approach is specialized to a linear network flow system with unknown but bounded demand and politopic bounds on controlled flows. All results are derived via the Hamilton-Jacobi-Isaacs and viscosity theory.
Anomalous and Not-So-Common Behavior in Common Ionic Liquids and Ionic Liquid-Containing Systems
2019
This work highlights unexpected, not so well known responses of ionic liquids and ionic liquid-containing systems, which are reported in a collective manner, as a short review. Examples include: (i) Minima in the temperature dependence of the isobaric thermal expansion coefficient of some ILs; (ii) Viscosity Minima in binary mixtures of IL + Molecular solvents; (iii) Anomalies in the surface tension within a family of ILs; (iv) The constancy among IL substitution of Cp/Vm at and around room temperature; (v) ILs as glass forming liquids; (vi) Alternate odd-even side alkyl chain length effects; (vii) Absolute negative pressures in ILs and IL-containing systems; (viii) Reversed-charged ionic l…
Nanotechnology for Natural Medicine: Formulation of Neem Oil Loaded Phospholipid Vesicles Modified with Argan Oil as a Strategy to Protect the Skin f…
2021
Neem oil, a plant-derived product rich in bioactives, has been incorporated in liposomes and hyalurosomes modified by adding argan oil and so called argan-liposomes and argan-hyaluro-somes. Argan oil has also been added to the vesicles because of its regenerative and protective effects on skin. In the light of this, vesicles were specifically tailored to protect the skin from oxidative stress and treat lesions. Argan-liposomes were the smallest vesicles (~113 nm); the addition of sodium hyaluronate led to an increase in vesicle size (~143 nm) but it significantly improved vesicle stability during storage. In vitro studies confirmed the free radical scavenging activity of formula-tions, irre…
The calculation of the number-average degree of polymerization starting from intrinsic viscosity and overall rate
1962
The relation between the intrinsic viscosity [η] and the number-average degree of polymerization Pn is a function of the molecular weight distribution of the polymer. In a polymer in which the termination of polymer radicals occurs partly by combination of two growing chains, this molecular weight distribution depends on number and extent of additional reactions such as chain transfer; i.e., it is variable. Therefore Pn of such polymers cannot be obtained from intrinsic viscosity measurements by means of an equation of the type [η] = KPna. A new method is proposed which allows the evaluation of Pn in these cases, without necessity of osmotic (or related) measurements or fractionation. The v…
Impact of oxidoreduction potential and of gas bubbling on rheological properties of non-fat yoghurt
2010
International audience; The aim of this work was to study the effect of different gaseous conditions on the physico-chemical properties of yoghurt. Four conditions of oxidoreduction potential (Eh7), +433 mV (milk gassed with air), +405 mV (ungassed milk), +283 mV (milk gassed with N2) and −349 mV (milk gassed with N2–H2) were applied to milk. The rheological properties and microstructure of these yoghurts were determined by measuring apparent viscosity, whey separation (WS) and using confocal laser scanning microscopy. Exopolysaccharide (EPS) production by lactic acid bacteria (LAB) was also studied, and production was increased for extreme Eh7 values: the highest values were obtained for a…
Evaluation of viscoelastic constants of metallic materials by laser-ultrasonics at elevating temperature
2002
The main objective of this study is the determination of elastic moduli and viscosity coefficients of metals at elevating temperature up to melting point. More specifically, it involves the analysis of the propagation of acoustic waves generated and detected simultaneously by laser-ultrasonic for the measurement of longitudinal and shear velocities. This preliminary work primarily concerns Tin (Sn) metal known for its low melting point and attenuation coefficient.