Surface active drugs: self-association and interaction with membranes and surfactants. Physicochemical and biological aspects

Shape memory alloys (SMAs) are a class of alloys that possess numerous unique characteristics. They offer complete shape recovery after experiencing large strains, energy dissipation through hysteresis of response, excellent resistance to corrosion, high fatigue resistance, and high strength. These features of SMAs, which can be exploited for the use in control of civil structures subjected to seismic events, have attracted the interest of many researchers in structural engineering over the past decades. This article presents an extensive review of seismic applications of SMAs. First, a basic description of two unique effects of SMAs, namely shape memory and superelastic effect, is provided. Then, the mechanical characteristics of the most commonly used SMAs are discussed. Next, the material models proposed to capture the response of SMAs in seismic applications are briefly introduced. Finally, applications of SMAs to buildings and bridges to improve seismic response are thoroughly reviewed.

Seismic Response Control Using Shape Memory Alloys: A Review

Thermodynamic analysis of thermal measurements in thermoelastic martensitic transformations

We combine analysis of measurements by femtosecond optical spectroscopy, computer simulations, and the generalized Mulliken−Hush (GMH) theory in the study of electron-transfer reactions and electro...

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Solvent as electron donor: Donor/acceptor electronic coupling is a dynamical variable

The mode of association of amphiphilic drugs in aqueous solution

The 1H NMR spectrum of chlorpromazine hydrochloride was fully assigned at 400 MHz. Similarly, the 13C NMR spectrum was assigned unambiguously using two-dimensional NMR. Measurements of chemical shift as a function of concentration in D2O showed appreciable changes of shift of both protons and carbons which were apparent even at solution concentrations two orders of magnitude lower than the critical micelle concentration (CMC). The relative magnitude of the shifts of the aromatic protons and carbons on dilution below the CMC were compatible with vertical stacking of the molecules in an off-set manner such that maximum overlap of the chlorinated rings occurred. Proton chemical shift data were interpreted using a stepwise association model to quantify the extent of association in the pre-CMC region.

1H and 13C NMR studies of the self-association of chlorpromazine hydrochloride in aqueous solution

Martensitic transformations in shape-memory alloys: Successes and failures of thermal analysis and calorimetry

The association characteristics of an amphiphilic phenothiazine drug, promethazine hydrochloride, in aqueous solutions containing high concentrations of electrolyte have been examined by heat conduction calorimetry. The application of deconvolution techniques has permitted the continuous determination of the concentration dependence of the apparent molar enthalpy extending to regions of high dilution. Theoretical treatments have been derived to describe thermogenesis in solutions of amphiphilic compounds exhibiting a range of association patterns. The calorimetric data for promethazine hydrochloride in the presence of 0.2-0.6 mol dm -3 sodium chloride could be satisfactorily described by an association scheme in which a primary unit of 3-4 monomers is formed below the critical micelle concentration by a continuous self-association process and grows with increasing concentration by the stepwise addition of monomers

A calorimetric study on the self-association of an amphiphilic phenothiazine drug in aqueous electrolyte solutions

Apparent molar enthalpies have been determined as a function of concentration by heat conduction calorimetry for aqueous solutions of the phenothiazine drugs chlorpromazine hydrochloride, promethazine hydrochloride, and promazine hydrochloride in the presence of added electrolyte (0.025−0.10 mol dm-3 NaCl). The concentration dependence of the apparent molar enthalpy could be quantitatively described using a mass action model of association based on the Guggenheim equations for the activity coefficients for mixed electrolytes. Derived values of the monomer−counterion interaction coefficient became increasingly negative with increase of salt concentration, suggesting that electrolyte addition promoted association at concentrations below the critical micelle concentration (cmc). Calculations of the fraction of each drug in the form of micelles as a function of concentration further confirmed the tendency for premicellar association. Significant differences in properties were observed between promethazine and...

H. Tachoire

Papers

1H and 13C NMR studies of the self-association of chlorpromazine hydrochloride in aqueous solution

Martensitic transformations in shape-memory alloys: Successes and failures of thermal analysis and calorimetry

A calorimetric study on the self-association of an amphiphilic phenothiazine drug in aqueous electrolyte solutions

A calorimetric study of the influence of electrolyte on the micellisation of phenothiazine drugs in aqueous solution

Thermogenese: Application des filtrages electronique et numerique inverses en calorimetre a conduction