The wave nature of biomolecules and fluorofullerenes

We demonstrate quantum interference for tetraphenylporphyrin, the first biomolecule exhibiting wave nature, and for the fluorofullerene C60F48 using a near-field Talbot-Lau interferometer. For the porphyrins, which are distinguished by their low symmetry and their abundant occurence in organic systems, we find the theoretically expected maximal interference contrast and its expected dependence on the de Broglie wavelength. For C60F48 the observed fringe visibility is below the expected value, but the high contrast still provides good evidence for the quantum character of the observed fringe pattern. The fluorofullerenes therefore set the new mark in complexity and mass (1632 amu) for de Broglie wave experiments, exceeding the previous mass record by a factor of two.Comment: 5 pages, 4 figure

Structure and Crystallographic Texture Changes of Ferritic Martensitic Steel Resulting from Thermal Creep and Ageing Tests

Thermal ageing (650 and 700∘C during 1000, 7000 or 13300 h) and creep (700∘C, 50 MPa) tests of tubes made from ferritic-martensitic steels EK181 and ChS139 were carried out. With the aid of X-ray techniques the investigation of crystallographic texture and structure condition after tests was conducted. Thermal ageing provides substructure enhancement. With the increase of ageing time one can note the decrease of microhardness and X-ray peaks broadening, which indicates inner elastic microstress relaxation. It was revealed that changes of crystallographic texture in the rupture area of steel ChS139 tube after creep test is similar to those after uniaxial tensile test at room temeprature. This indicates the similarity of the mechanisms ofgrain reorientation for creep and tension. Recrystallization occurs in steel EK181 during creep test at temperature 700∘C leading to formation of recrystallization texture. This results in faster failure of steel EK181 (2486 h before rupture) in comparison with steel ChS139 (3426 h)

A thermochemical study of aqueous solutions of sodium naproxene

The enthalpies of solution of sodium naproxene and dilution of its aqueous solutions were measured on an isoperibolic calorimeter at 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K. The maximum content of the electrolyte was determined by its solubility at the given temperature (0.038\u20130.083 mol/kg solvent). The Pitzer model was used to obtain the virial coefficients for calculations of many excess thermodynamic properties of both solutions and their components. Changes in these characteristics depending on the concentration and temperature are considered

Solubility of Diflunisal in Supercritical Carbon Dioxide

The solubility of diflunisal, a nonsteroidal anti-inflammatory drug (NSAID), in supercritical carbon dioxide (scCO2) was measured at (308.2, 318.2, and 328.2) K and in the pressure range from (9.0 up to 25.0) MPa. Results were obtained using a static analytical method. Experimental solubility was found to be between 0.54·10−6 and 8.07·10−6 (in terms of diflunisal mole fraction). Experimental data were satisfactorily correlated with an equation-of-state (EOS) model: the Peng−Robinson cubic equation of state (PR−EOS) together with the conventional van der Waals mixing and combining rules. Solid properties were estimated by different methods available in the literature. The solubilities of several NSAIDs in SCFs, namely in scCO2, were obtained from the literature and plotted and represented as a function of the corresponding sublimation pressures and fusion temperatures

Thermodynamics of sodium diclofenac salt aqueous solutions at various temperatures

Enthalpies of solution and dilution of aqueous solutions of sodium diclofenac salt were measured by isoperibolic calorimeter at 293.15, 298.15, 303.15, 308.15 and 318.15 K. The concentration of the electrolyte was restricted to solubility salt at various temperatures and did not exceed 0.035-0.057 mol\ub7kg-1 values depending on the studied temperature. The virial coefficients were derived from Pitzer\u2019s model and the excess thermodynamic functions of both the solution and the components of the solution were calculated. The analysis of thermodynamic characteristics of the solution from concentration and temperatures was carried out and discussed

Crystal structure of a 1:1 salt of 4-aminobenzoic acid (vitamin B10) with pyrazinoic acid

The title 1:1 salt, C7H8NO2+·C5H3N2O2− (systematic name: 4-carboxyanilinium pyrazine-2-carboxylate), was synthesized successfully by slow evaporation of a saturated solution from water–ethanol (1:1 v/v) mixture and characterized by X-ray diffraction (SCXRD, PXRD) and calorimetry (DSC). The crystal structure of the salt was solved and refined at 150 and 293 K. The salt crystallizes with one molecule of 4-aminobenzoic acid (PABA) and one molecule of pyrazinoic acid (POA) in the asymmetric unit. In the crystal, the PABA and POA molecules are associated via COOH...Narom heterosynthons, which are connected by N—H...O hydrogen bonds, creating zigzag chains. The chains are further linked by N—H...O hydrogen bonds and π–π stacking interactions along the b axis [centroid-to-centroid distances = 3.7377 (13) and 3.8034 (13) Å at 150 and 293 K, respectively] to form a layered three-dimensional structure