Sulfate is one of the most important aerosols in the atmosphere. A new sulfate formation pathway via synergistic reactions between SO(2) and NO(2) on mineral oxides was proposed. The heterogeneous reactions of SO(2) and NO(2) on CaO, α-Fe(2)O(3), ZnO, MgO, α-Al(2)O(3), TiO(2), and SiO(2) were investigated by in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (in situ DRIFTS) at...

a twin pregnancy with a coexisting complete hydatidiform mole and a healthy fetus (cmcf) is rare. here we report three cases of cmcf with different clinical courses but similar outcome without a surviving neonate. two women required uterine evacuation before 20 weeks of gestational age because of vaginal bleeding and medical complications and the other patient underwent termination of her pregn...

The primary coexisting mineral with galena is sphalerite. Hence, it critical to selectively separate from sphalerite by flotation. In this work, thiourea and related derivatives as potential flotation collectors for separating were investigated. Thiourea its found be effective selective in batch studies of a single mineral, 1,1-diphenylthiourea (11DTA) emerging the best choice. Galena has super...

Zoned, silica-deficient, calcic garnets containing up to 5 mol% F substitution for 0 formed during contact metamorphism of basalts by the Skaergaard intrusion in East Greenland. Fluorian calcic garnets occur as a retrograde alteration of prograde wollastonite and clinopyroxene that fills vesicles and vugs in lavas 30-70 m from the intrusion. Paragenetically equivalent phases include fluorite, w...

Silver-bearing zinc-iron tetrahedrite-tennantite and freibergit fahlores approximating the simplified formula (Ag,Cu)m(Fe,Zn)2(As,Sb)4S~3 have been equilibrated with excess electrum (AuxAgl_~) and chalcopyrite + pyrite + iron-bearing sphalerite (CuFeS2 + FeS2 + Fe0.05Zn0.95S) in evacuated silica tubes at 300 ~ in reversed silver-copper exchange experiments with less than 0.1 mg NH4CI added as a...

The aim of this research was to develop a simple procedure for a highly sensitive determination of low-molecular-weight (LMW) carbonyl compounds in drinking water and natural water. We employed a preconcentration HPLC system with 2,4-dinitrophenylhydrazine (DNPH) for the determination of LMW carbonyl compounds. A C-18 reverse-phase preconcentration column was used instead of a sample loop at th...

Native lead, a rare mineral, occurs in a late-stage vein in the world’s largest lead – zinc – silver deposit, at Broken Hill, Australia. The lead-bearing vein consists mainly of laumontite, quartz, biotite and muscovite, together with minor amounts of lead, galena, sphalerite, molybdenite, and rare allanite-(Ce). Three types of fluid inclusions have been identified: two-phase brine inclusions l...

Microtextural and experimental studies have yielded conflicting data on the relative mechanical strengths of muscovite and biotite [Wilson and Bell, 1979; Kronenberg et al., 1990; Mares and Kronenberg, 1993]. We propose a crystal-chemical resolution to this conflict, namely, that (001) dislocation glide in biotite is rate-limited by its fluorine content. Significant F(OH)_• substitution, and co...