Molecular response of liquid nitrogen multiply shocked to 40 GPa.

Liquid nitrogen was subjected to multiple shock compression to examine its response to pressures (15-40 GPa) and temperatures (1800-4000 K) previously unexplored in static and shock compression studies. Raman spectroscopy measurements were used to characterize the molecular bond response and to determine temperatures in the peak state. By extending our analysis to include other Raman spectroscopy measurements, an empirical relation was developed that describes the pressure and temperature dependence of the Raman shift (of the 2330 cm(-1) mode) for both shock and static compression.

Temperature measurements and an improved equation of state for shocked liquid benzene.

Time-resolved, Raman spectroscopy measurements were used to determine temperatures in multiply shocked liquid benzene to peak pressures of ~19 GPa. The previously reported equation of state (EOS) for benzene provides temperatures that are lower than the experimental measurements. To achieve improved temperature calculations, key thermodynamic parameters in the existing EOS were varied to examine and understand the sensitivity of temperatures to those parameters.

Investigation of LiAlH4-THF formation by direct hydrogenation of catalyzed Al and LiH.

The formation of LiAlH(4)-THF by direct hydrogenation of Al and LiH in tetrahydrofuran (THF) was investigated using spectroscopic and computational methods. The molecular structures and free energies of the various possible adducts (THF-AlH(3), THF-LiH and THF-LiAlH(4)) present in a LiAlH(4)/THF solution were calculated and the dominant species were determined to be contact ion pairs where three THF molecules coordinate the lithium. Raman and X-ray absorption spectroscopy were used to investigate the effect of different Ti precursors on the formation of Al-H species and LiAlH(4)-THF and determine the optimal reaction conditions.

[The influence of short-term magnesium carbonate treatment on calcium-phosphorus balance in dialysis patients].

Introduction: The phosphate-binders presently used in the treatment of calcium-phosphorus disorders in dialysis patients remain a crucial element of cardio-vascular protection. The aim of the study was to assess short-time magnesium carbonate treatment efficacy in hemodialysis patients with hyperphosphatemia.

Material And Methods: The study involved 64 participants (32 male and 32 female) aged 29-84 years, with end-stage renal disease, hyperphosphatemia (> 1.

Thermochemistry of Alane Complexes for Hydrogen Storage: A Theoretical and Experimental Investigation.

Knowledge of the relative stabilities of alane (AlH(3)) complexes with electron donors is essential for identifying hydrogen storage materials for vehicular applications that can be regenerated by off-board methods; however, almost no thermodynamic data are available to make this assessment. To fill this gap, we employed the G4(MP2) method to determine heats of formation, entropies, and Gibbs free energies of formation for 38 alane complexes with NH(3-n)R(n) (R = Me, Et; n = 0-3), pyridine, pyrazine, triethylenediamine (TEDA), quinuclidine, OH(2-n)R(n) (R = Me, Et; n = 0-2), dioxane, and tetrahydrofuran (THF). Monomer, bis, and selected dimer complex geometries were considered.