The Viking Landers were unable to detect evidence of life on Mars but, instead, found a chemically reactive soil capable of decomposing organic molecules. This reactivity was attributed to the presence of one or more as-yet-unidentified inorganic superoxides or peroxides in the martian soil. Using electron paramagnetic resonance spectroscopy, we show that superoxide radical ions (O2-) form dire...

X-ray diffraction refinement of the crystal structure of eosphorite has been carried out with reference to the orthorhombic space group Cmca. The structure is similar to that previously described by Hanson (1960), but the standard deviations are improved. Optical absorption and photoluminescence have also been studied for this mineral. Two sharp emission lines, denoted as R[ and R2' superimpose...

A synthetic Topopah Spring Tuff water representative of one type of pore water at Yucca Mountain, NV was evaporated at 95 °C in a series of experiments to determine the geochemical controls for brines that may form on, and possibly impact upon the long-term integrity of waste containers and drip shields at the designated high-level, nuclear-waste repository. Solution chemistry, condensed vapor ...

Ibliform barnacles are among the few invertebrate animals harnessing calcium phosphate to construct hard tissue. The (31)P solid-state NMR (SSNMR) signal from the shell plates of Ibla cumingi (Iblidae) is broader than that of bone, and shifted by ca 1 ppm to low frequency. (1)H-(31)P heteronuclear correlation (HETCOR) experiments show a continuum of different phosphorus/phosphate atomic environ...

Skin and subcutaneous lesions of 2 cases with natural occurring Cushing’s disease and 1 case with calcinosis circumscripta were compared. Case 1 was typical of osteoma cutis, containing somewhat regularly arranged discrete ossification foci in the mid and deep dermis. Case 2 had layers of “mille feuille”, yellowish to white gritty chalky substances diffusely scattered in the subcutis, seen hist...

Formulas proposed for the mineral of bone were reviewed. Literature data were collected where Ca, P, Na, Mg and CO3 are determined in the same samples. These data were analyzed for their conformity to the above mentioned formulas. According to this analysis Mg is contained in a phase having the Ca/P of magnesium whitlockite within the limites of error. Na is contained in a carbonated calcium ph...

This paper describes reactive transport simulations conducted to assess the impact of mineral fouling on the hydraulic behavior of continuous-wall permeable reactive barriers (PRBs) employing granular zero-valent iron (ZVI) in carbonate-rich alluvial aquifers. The reactive transport model included a geochemical algorithm for simulating corrosion and mineral precipitation reactions that have bee...

Humans generally consume a diet that generates metabolic acids leading to a reduction in the concentration of systemic bicarbonate and a fall in pH. In vitro experiments indicate that this metabolic acidosis causes a release of calcium from bone that initially is simply due to physicochemical dissolution of the mineral. On a more chronic basis metabolic acidosis alters bone cell function; there...

Over the last decades, significant advances have been made in the study of adsorption processes at mineral–water interfaces. In particular, surface-enhanced infrared (IR) techniques, and, more recently, non-linear vibrational sum-frequency spectroscopy have provided novel insights into the structure and dynamics of these interfaces. The driving forces behind adsorption at mineral substrates are...

A new approach to capture and store CO(2) by mineral carbonation using recyclable ammonium salts was studied. This process integrates CO(2) capture with mineral carbonation by employing NH(3), NH(4)HSO(4), and NH(4)HCO(3) in the capture, mineral dissolution, and carbonation steps, respectively. NH(4)HSO(4) and NH(3) can then be regenerated by thermal decomposition of (NH(4))(2)SO(4). The use of...