On the nature of the hard X-ray source IGR J2018+4043

We found a very likely counterpart to the recently discovered hard X-ray source IGR J2018+4043 in the multi-wavelength observations of the source field. The source, originally discovered in the 20-40 keV band, is now confidently detected also in the 40-80 keV band, with a flux of (1.4 +/- 0.4) x 10(-11) erg cm(-2) s(-1). A 5 ks Swift observation of the IGR J2018+4043 field revealed a hard point-like source with the observed 0.5-10 keV flux of 3.4(+0.7)(-0.8) x 10(-12) erg cm(-2) s(-1) (90% confidence level) at alpha = 20h18m38.55s, delta = +40d41m00.4s (with a 4.2" uncertainty). The combined Swift-INTEGRAL spectrum can be described by an absorbed power-law model with photon index gamma = 1.3 +/- 0.2 and N_H = 6.1(+3.2)(-2.2) x 10(22) cm(-2). In archival optical and infrared data we found a slightly extended and highly absorbed object at the Swift source position. There is also an extended VLA 1.4 GHz source peaked at a beam-width distance from the optical and X-ray positions. The observed morphology and multiwavelength spectra of IGR J2018+4043 are consistent with those expected for an obscured accreting object, i.e. an AGN or a Galactic X-ray binary. The identification suggests possible connection of IGR J2018+4043 to the bright gamma-ray source GEV J2020+4023 (3EG J2020+4017) detected by COS B and CGRO EGRET in the gamma-Cygni SNR field.Comment: 5 pages, 3 figures, uses emulateapj styl

Effects of adaptation to sea water, 170% sea water and to fresh water on activities and subcellular distribution of branchial Na + −K + -ATPase, low- and high affinity Ca ++ -ATPase, and ouabain-insensitive ATPase in Gillichthys mirabilis

1. Branchial activities of Na + −K + -ATPase, ouabain-insensitive ATPase, (Mg ++ -ATPase) and Ca ++ -ATPase were measured in Gillichthys mirabilis after adaptation to salinities ranging from 170% SW to FW. Stabilities of these activities against freezing and deoxycholate solubilization and the temperature-dependence of activity rates were also investigated. Subcellular distribution and some kinetic properties of these activities, and of SDH were compared in branchial tissues of fish adapted to 170% SW and to FW.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47126/1/360_2004_Article_BF00782593.pd

The terrestrial-marine interface: modelling nitrogen transformations during its transfer through the Scheldt River system and its estuarine zone

A budget of nitrogen transformations during its transfer through the river system and the estuary of the Scheldt shows that as much as 70% of total N discharged into the river system is eliminated before reaching the sea. Denitrification and, indirectly, primary production appear as significant processes in this elimination. The factors controlling the intensity of these processes, both in the river system and in the estuary, are identified. This allows mathematical modeling of these processes and prediction of the impact of large-scale wastewater purification policies on the input of nitrogen into the Belgian coastal zone

Techniques for cardiac image segmentation

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Synthesis, characterization and catalytic activity of single site, Lewis acidic aluminosilicates

A general synthetic strategy for the preparation of atomically dispersed, well-defined Lewis acidic aluminum sites in silicate matrices is described and illustrated. These amorphous matrices are composed of the spherosilicate cubes (Si8O20) linked together by combinations of aluminum and siloxane groups. The connectivity of the catalytically active aluminum centers to the surrounding silicate matrix can be varied by choice of aluminum precursor. “Extraframework” 3-connected Al⟵Py and Al⟵THF sites are obtained from the corresponding AlCl3·L complexes and 4-connected “framework” sites from Y[AlCl4] (Y = Lutidinium, [Bu4N]+). The aluminum sites in these porous silicates are characterized by gravimetry, IR and multinuclear SSNMR spectroscopies as well as ligand exchange reactions. Their catalytic activities as Lewis acids are investigated for the aminolysis of styrene oxide by aniline. These single site aluminosilicate catalysts exhibit activities that are comparable to or better than analogous, well-known zeolite and amorphous aluminosilicate materials. Their activities are dependent on the connectivity of aluminum to the surrounding silicate matrix as well as the length and flexibility of secondary linkers in the matrix

A review on catalytic oxidation of chloroaromatics from flue gas

Commercial catalysts for the catalytic oxidation of chloroaromatics are mainly based on either noble metals or transition metal oxides supported on a suitable carrier. This paper reviews studies relative to these two generic groups of catalysts and their performances for chloroaromatic decomposition, i.e. conversion efficiency, stability and selectivity towards harmless products (e.g., CO2), and in particular, avoiding the formation of polychlorinated by-products. The various approaches towards improved catalysts, including tuning the support, adding dopants or promoters, improving the preparation methods, or auxiliary means such as the introduction of ozone (O3) or hydrogen peroxide (H2O2) in the gas to be treated, and combination with non-thermal plasma treatment are systematically reviewed. This review also appraises various modes of deactivation (i.e., originating from fouling, coking, poisoning, sintering of the catalyst, and from volatilization of its active phases) as well as possible methods for regeneration

Synthesis of high surface area aluminophosphate and -phosphonate xerogels by non-hydrolytic sol-gel reactions

We disclose the preparation of high-surface-area mesoporous aluminophosphates and aluminophosphonates by the non-hydrolytic sol-gel reactions (NHSG) of Al(NMe2)3 with trimethylsilylated phosphate OP(OSiMe3)3, phosphonates RP(O) (OSiMe3)2 (R = Me, tBu, Ph), and bis-phosphonates (Me3SiO)2(O)P–X–P(O) (OSiMe3)2 (X = C6H4, (C6H4)2) in dry toluene. The reactions proceed by silylamine elimination of Me3SiNMe2 to provide organic-inorganic hybrid xerogels with properties influenced by organic substituents and the Al:P ratio of the precursors. Dried xerogels exhibit large surface areas (up to 1000 m2 g−1) and matrices based on condensed Al–O–P networks. They stay stable under relatively harsh thermal conditions. 27Al, 13C, and 29Si solid-state NMR spectroscopy was employed to characterize the aluminum coordination and the residual amido and trimethylsilyl groups. The catalytic performance of NHSG prepared material was examined in gas-phase dehydration of ethanol to ethylene exhibiting conversion and selectivity comparable to weak solid acid benchmark catalysts. The number of unreacted surface groups was determined by gravimetric measurements and by thermal analysis (TG-DSC). These residual groups have the potential to be used in post-synthetic grafting of catalytically active metal centers