We measured the emf of a sodium ion-selective electrode in NaCl-NaHCO3 solutions (160 mmol of Na+, 160-120 mmol of Cl-, and 0-40 mmol HCO3- per liter) with a home-built cell in steady-state after 10 min and with two commercial direct potentiometric analyzers about 20 s after the sample was introduced. Substitution of HCO3- for Cl- resulted in a small decrease in emf. We calculated the effect of...

The present study investigates the chemical composition, solubility, and physical and mechanical properties of carbonate hydroxyapatite (CO3Ap) and silicon-substituted carbonate hydroxyapatite (Si-CO3Ap) which have been prepared by a simple precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF) spectroscopy, and inductively couple...

The sulfur content of planktonic and benthic foraminifera was measured in specimens recovered from deep-sea sediment cores and individuals grown in culture. A new method for measuring sulfur in foraminiferal calcium carbonate was developed, employing a high-resolution inductively coupled plasma-mass spectrometer. The sulfur measurements, expressed as sulfur-to-calcium (S/Ca) ratios in the foram...

The cycling performance and SEI composition of Si nano-particle anodes in electrolytes containing 5–25 wt% fluoroethyelene carbonate (FEC) and 3–6 wt% vinylene carbonate (VC) has been investigated by a combination of by electrochemical cycling, electrochemical impedance spectroscopy, IR-ATR and XPS. The incorporation of FEC or VC changes the cycling performance, impedance, electrode morphology,...

The Martian meteorite ALH84001 preserves evidence of interaction with aqueous fluids while on Mars in the form of microscopic carbonate disks. These carbonate disks are believed to have precipitated 3.9 Ga ago at beginning of the Noachian epoch on Mars during which both the oldest extant Martian surfaces were formed, and perhaps the earliest global oceans. Intimately associated within and throu...

Site U1317 (proposal Site PORC-3A) is located on the northwest shoulder of the Challenger Mound (51o 22.8 N, 11o 43.1W, in 781 to 815 m water depth). Scientific drilling of the Challenger Mound was the central objective of Expedition 307. Specific objectives of drilling Site U1317 were: • To establish whether the mound base is on a carbonate hardground of microbial origin and whether past geofl...

A series of RuII complexes stabilized with the pentapyridyl ligand Py5Me2 (Py5Me2 = 2,6-bis(1,1-bis(2-pyridyl)ethyl)pyridine) and with an axial X ligand (X = Cl-, H2O, N3-, MeCN) were prepared and characterized in the solid state and in non-aqueous solution. The cyclic voltammograms of these complexes in MeCN reflect a reversible substitution of the axial X ligand with MeCN. Irreversible ligand...

The quantitative description of the interactions of uranium with blood serum components is of high relevance for a rational design of molecules suitable for in vivo chelation of uranium. We have determined the stability constants for the complexation of U(VI) with human serum transferrin and albumin by time-resolved laser-induced fluorescence spectroscopy and difference ultraviolet spectroscopy...