Herein, the influence of Cr additions on solidification parameters, as-cast microstructures, and mechanical properties Al–Si alloys with Fe-impurity is investigated. Al–Si–Cr 3% 7% Si 0.25% 0.40% are developed. Solidification experiments performed using an instrumented cooling casting apparatus permitting obtainment vertical upward-solidified ingots. The morphological phase structures character...

We derive parameters and abundances of several elements in two cool Pleiades dwarfs, four cool NGC 2264 preÈmain-sequence stars, and a probable NGC 2264 nonmember from high-resolution, moderate signal-to-noise ratio, Keck/HIRES spectra. Our Pleiades Fe abundance agrees with previous spectroscopic and photometric values of hotter stars and does not resolve the 0.3 mag distance modulus discrepanc...

We calculate presupernova evolutions and supernova explosions of massive stars (M = 13 − 25M⊙) for various metallicities. We find the following characteristic abundance patterns of nucleosynthesis in the metal-free (Pop III) stars. (1) The α-nuclei (from C to Zn) are more efficiently produced than other isotopes, and the abundance pattern of α-nuclei can be similar to the solar abundance. In pa...

abstruct anzali wetland in north of guilan provience is an international important wetland that is recorded in ramsar convension. pollution is one of the major problems facing this wetland. in order to investigate the pollution situation, sediment core samples were taken in 7 stations in 4 districts within the wetland, namely abkenar, siakishom, hendekhale and shijan). elements were determined ...

Background: Considering the toxic effects of heavy metals and microbial pathogens in industrial wastewaters, it is necessary to treat metal and microbial contaminated wastewater prior to disposal in the environment. The purpose of this study is to assess the removal of heavy metals pollution and microbial contamination from a mixture of municipal and industrial wastewater using membrane biorea...

Powdered samples of a suite of 14 CR and CR-like chondrites, ranging from petrologic grade 1 to 3, were spectrally characterized over the 0.3–2.5 lm interval as part of a larger study of carbonaceous chondrite reflectance spectra. Spectral analysis was complicated by absorption bands due to Fe oxyhydroxides near 0.9 lm, resulting from terrestrial weathering. This absorption feature masks expect...

We quantified leaching and mass fractions of trace elements in melted acidified ice core samples measured by Inductively Coupled Plasma Sector Field Mass Spectrometry (ICP-SFMS). This assessment was conducted using nine ice core sections retrieved from various high-altitude drilling sites in South America, Africa, Asia and Europe. Twenty trace elements (Ag, Al, As, Bi, Cd, Co, Cr, Cu, Fe, Mn, M...

The syntheses, structures, and magnetic properties of compounds of formula [Fe(III)(5-Clsal(2)-trien)][Mn(II)Cr(III)(ox)(3)]·0.5(CH(3)NO(2)) (1), [Fe(III)(5-Brsal(2)-trien)][Mn(II)Cr(III)(ox)(3)] (2), and [In(III)(5-Clsal(2)-trien)][Mn(II)Cr(III)(ox)(3)] (3) are reported. The structure of the three compounds, which crystallize in the orthorhombic P2(1)2(1)2(1) chiral space group, presents a 3D ...