Search results for "Partition"
showing 10 items of 411 documents
Exemples de QSAR sur des coefficients de partage
2005
National audience
Assessment of the influence of counter ions on biosorption of copper cations in brewer's spent grain - Waste product generated during beer brewing pr…
2019
Abstract The influence that conditioning leached ground barley grain (known as “brewer's spent grain” (BSG)) has on the effectiveness of copper cation sorption was analysed. Saturation with counter ions of functional groups present on the grain surface was carried out in hydrochloric acid, sodium hydroxide, sodium and calcium chloride solutions. For comparison, BSG was also conditioned in demineralised water. Spent barley grain is a by-product of the brewing industry which can be used as a biosorbent in the removal of heavy metals from waste water. Emphasis is placed on the effect of competitive sorption of copper and hydrogen cations and the negative influence of a solution alkalinisation …
Effect of ionization and the nature of the mobile phase in quantitative structure-retention relationship studies.
2005
Abstract The octanol–water distribution constant, commonly called partition coefficient, Po/w, is a parameter often retained as a measure of the hydrophobicity of a molecule. log Po/w, for a given molecule, can be conveniently evaluated constructing correlation lines between standard retention factor logarithms (log k) in reversed-phase liquid chromatography (RPLC) and standard log Po/w values. Many compounds of pharmaceutical interest can be quite hydrophobic and have, simultaneously, basic nitrogen atoms or acidic sulfur containing groups in their structure. This renders them ionizable. The hydrophobicity of the molecular drug form (Po/w value) is completely different from its ionic form …
Donnan equilibrium of ionic drugs in pH-dependent fixed charge membranes: theoretical modeling.
2002
Abstract We have studied theoretically the partition equilibrium of a cationic drug between an electrolyte solution and a membrane with pH-dependent fixed charges using an extended Donnan formalism. The aqueous solution within the fixed charge membrane is assumed to be in equilibrium with an external aqueous solution containing six ionic species: the cationic drug (DH + ), the salt cations (Na + and Ca 2+ ), the salt anion (Cl − ), and the hydrogen and hydroxide ions. In addition to these mobile species, the membrane solution may also contain four fixed species attached to the membrane chains: strongly acid sulfonic groups (SO 3 − ), weakly acid carboxylic groups in dissociated (COO − ) a…
Coherence absorption and condensation induced by thermalization of incoherent nonlinear fields
2008
We show that a conservative system of incoherent nonlinear waves exhibits, as a rule, an irreversible process of coherence transfer, in which the incoherence of the system is absorbed by the small-amplitude field, thus allowing the high-amplitude field to evolve towards a highly condensed coherent state. This process of coherence absorption results from the natural thermalization of the fields to a thermodynamic equilibrium state. The theory reveals that, contrary to a classical gas system, a wave system does not satisfy an equipartition of energy among the particles. Such a distinctive feature is the key property underlying the existence of the coherence absorption process. The coherence a…
The effect of saline water on Phillyrea angustifolia L. seedlings
2013
Water limitations in the Mediterranean areas are very common and the use of saline water for plant irrigation is becoming a necessity. Salinity generally affects plant growth and physiological processes, and can eventually lead to leaf injuries and plant death. For these reasons, the selection of salt tolerant species is a priority for landscaping purposes in the Mediterranean areas. The objective of this study was to evaluate the effect of saline water on Phillyrea angustifolia plant performance. Seventy-five rooted cuttings were grown in the greenhouse in 4-liter pots and irrigated for 5 months with saline water at different NaCl concentrations for two consecutive years. In 2010, 45 plant…
The Holocaust, the Founding of Israel and the Arab-Israeli War in the British, Swedish and Finnish Press
2011
The fact that the gap between the founding of the state of Israel and the end of the Holocaust was only three years (almost to date), creates, at least in retrospect, a strong link between the two events. Articulating this view, Walter Harrelson has written that ‘[A] shamed world was certainly ready, after the Holocaust and the struggle of Jews from Europe to get to Israel, to support the Partition Plan that led to the establishment of the state.’1 Yehuda Bauer has argued that the birth of a nation ‘bridges the gap between an unconquered past tragedy and the hope for the resurrection of an almost mortally wounded people’.2 Peter Novick also agrees that the link exists, although in less cert…
Trace cocharacters and the Kronecker products of Schur functions
2003
Abstract It follows from the theory of trace identities developed by Procesi and Razmyslov that the trace cocharacters arising from the trace identities of the algebra Mr(F) of r×r matrices over a field F of characteristic zero are given by TCr,n=∑λ∈Λr(n)χλ⊗χλ where χλ⊗χλ denotes the Kronecker product of the irreducible characters of the symmetric group associated with the partition λ with itself and Λr(n) denotes the set of partitions of n with r or fewer parts, i.e. the set of partitions λ=(λ1⩽⋯⩽λk) with k⩽r. We study the behavior of the sequence of trace cocharacters TCr,n. In particular, we study the behavior of the coefficient of χ(ν,n−m) in TCr,n as a function of n where ν=(ν1⩽⋯⩽νk) i…
A Riemann-Type Integral on a Measure Space
2005
In a compact Hausdorff measure space we define an integral by partitions of the unity and prove that it is nonabsolutely convergent.
Mixed Phases, Phase Transitions, Stability of Matter
2016
Phase mixtures and phase transitions are two major themes of thermodynamics. A third one, related to the former, is the stability of macroscopic matter around us. Mixed phases can be analyzed and illustrated in a nice geometric way. Phase transitions are dealt with from the point of view of classical thermodynamics as well as in the framework of models of statistical mechanics.