Search results for "Ternary"
showing 10 items of 786 documents
Chemostratigraphy, magnetostratigraphy, chronology, palaeoenvironments and correlations.
2013
4 pages
Quaternary transition pathway in sol–gel encapsulated haemoglobin tracked by NIR and UV spectral relaxations
2008
→T structural transition of haemoglobin (hb), the protein responsible for oxygen (o) transport in the red blood cells of vertebrates, is the hall mark example. This transition, which regu lates o2 uptake in the lungs and o2 release in the tissues, is a switch in the quaternary structure of the protein from a low-affinity state (T) to a high-affinity state (R), two well-characterised structures. The struc tural pathway connecting the end states of this transition remains unclear, however, although recently several experimental 1 or
Quaternary Glaciations in the French Alps and Jura
2011
During last glacial maximum, the pre-existing relief of the Alps and the Jura Mountains controlled glacier development. The Jura massive morphology, only slightly dissected by valleys, resulted in a wide ice-sheet; and this situation contrasts with the Alps where numerous deep valleys were filled by big glaciers.
Polymer-polymer interaction, in the presence of a solvent as measured by viscometry
2001
Dilute solution viscometry experiments have been carried out in five ternary polymer systems solvent(1)/polymer(2)/polymer(3). Values of the specific viscosity of polymer (3) in a ‘binary solvent’ formed by polymer(2) + solvent(1) have been used to determine the compatibility of the polymer blends. Krigbaum and Wall formalism has been used to predict compatibility which relies on an interaction parameter that depends on the concentration, weight fraction and molar mass of each polymer. To reduce the dependences and to clarify the criterion of compatibility, a parameter independent of polymer (3) composition and molar mass has been deduced. This parameter shows the same behaviour with polyme…
The arid–humid transition in the Sahara and the Sahel during the last deglaciation
1990
At the time of the Last Glacial Maximum, the Sahara and Sahel regions of North Africa were extremely dry. New records of rainfall show that during the subsequent deglaciation, the transition from arid to humid conditions in these regions occurred synchronously in two main steps. Comparison with other records of palaeoclimate in Europe and the North Atlantic Ocean shows that certain common factors controlled changes in ocean and atmosphere dynamics during the deglaciation.
Recombinant NeutraLite Avidin: a non-glycosylated, acidic mutant of chicken avidin that exhibits high affinity for biotin and low non-specific bindin…
2000
AbstractA recombinant non-glycosylated and acidic form of avidin was designed and expressed in soluble form in baculovirus-infected insect cells. The mutations were based on the same principles that guided the design of the chemically and enzymatically modified avidin derivative, known as NeutraLite Avidin. In this novel recombinant avidin derivative, five out of the eight arginine residues were replaced with neutral amino acids, and two of the lysine residues were replaced by glutamic acid. In addition, the carbohydrate-bearing asparagine-17 residue was altered to an isoleucine, according to the known sequences of avidin-related genes. The resultant mutant protein, termed recombinant Neutr…
Polymeric scaffolds prepared via Thermally Induced Phase Separation (TIPS): Tuning of structure and morphology
2007
Scaffolds suitable for tissue engineering applications were prepared by Thermally Induced Phase Separation (TIPS) starting from a ternary solution PLLA/dioxane/water. The experimental protocol consisted of three consecutive steps, a first quench from the homogeneous solution to an appropriate demixing temperature (within the metastable region), a holding stage for a given residence time and a final quench from the demixing temperature to a low temperature (within the unstable region). A large variety of morphologies, in terms of average pore size and interconnection, were obtained upon modifying the demixing time and temperature, owing to the interplay of nucleation and growth processes dur…
Using 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate as an Entrainer for the Extractive Distillation of Ethanol + Water Mixtures
2009
Isobaric vapor−liquid equilibria (VLE) for the ethanol + water + [emim][triflate] ternary system have been obtained at 100 kPa using a recirculating still. The ethanol + water binary system was also obtained. Furthermore, data were simulated with the Mock’s electrolyte nonrandom two-liquid (NRTL) model, using the solvent−solvent interaction parameters obtained from VLE data of the ethanol + water system and taking the solvent−ionic liquid (IL) interaction parameters for the other binary systems from previous works. The agreement between experimental and calculated data is very good, showing the predictive capacity of the model. The addition of [emim][triflate] produces the disappearance of …
Calculation of phase diagrams not requiring the derivatives of the Gibbs energy for multinary mixtures
1996
A method for the calculation of phase diagrams (tie lines and binodal, spinodal, critical points and their stability) based exclusively on the Gibbs energy of mixing with no need of its derivatives with respect to the composition variables is extended to multinary mixtures for any number of components. The mathematical description of the (K-1)-dimensional phase diagram of a K-component mixture is presented. The method is demonstrated for a quinternary blend of five polymers exhibiting a closed miscibility gap; all binary, ternary and quaternary subsystems are completely miscible. The phase separation in the quinternary system is caused by very favorable interactions in the ternary subsystem…