نتایج جستجو برای: cobalt
تعداد نتایج: 30285 فیلتر نتایج به سال:
Among the fundamental transformations that comprise a catalytic cycle for cross coupling, transmetalation from the nucleophile to the metal catalyst is perhaps the least understood. Optimizing this elementary step has enabled the first example of a cobalt-catalyzed Suzuki-Miyaura cross coupling between aryl triflate electrophiles and heteroaryl boron nucleophiles. Key to this discovery was the ...
Six Co-Rh/Fe3O4 catalysts with different cobalt loadings were prepared by the co-precipitation of RhCl3, Co(NO3)2, and Fe(NO3)3 using Na2CO3 as the precipitant. These catalysts were tested for dicyclopentadiene (DCPD) hydroformylation to monoformyltricyclodecenes (MFTD) and diformyltricyclodecanes (DFTD). The results showed that the MFTD formation rate increased with increasing cobalt loading, ...
Cobalt (II) reacts with 5-methylfuran-2-carbaxaldehyde thiosemicarbazone (5-MFAT) and forms a light yellow colored complex, which was extracted into isobutanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance value of the Co (II)–5-MFAT complex was measured at different intervals of time at 360 nm, to ascertain the time stability of the complex. The extraction of the complex...
This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on alumina. The catalysts were prepared by a wet impregnation method. Samples were characterized using temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), CO-chemisorption, transmission electron microscopy (TEM), field emission scanning electr...
We overview the current status and future directions of the Cobalt project. Cobalt is a domainspecific language for implementing compiler optimizations as guarded rewrite rules. Cobalt optimizations operate over a C-like intermediate representation including unstructured control flow, pointers to local variables and dynamically allocated memory, and recursive procedures. The design of Cobalt en...
Tumor cells are often found under hypoxic conditions due to the rapid outgrowth of their vascular supply, and, in order to survive hypoxia, these cells induce numerous signaling factors. Akt is an important kinase in cell survival, and its activity is regulated by the upstream phosphoinositide 3-kinase (PI3K) and receptor tyrosine kinases (RTKs). In this study, we examined Akt activation and RT...
Trace metal content was measured in airborne particulates in Wve towns located in west central Nevada with an emphasis on Fallon, where 16 cases of childhood leukemia were diagnosed recently. Airborne dust samples were collected using portable, high-volume particulate air samplers, and each Wlter was chemically analyzed by acid-dissolution, inductively coupled plasma mass spectroscopy. Tungsten...
The local electronic structure of the cobalt centre-ion of Co(III) protoporphyrin IX chloride dissolved in dimethyl sulfoxide (DMSO) liquid solution is studied by resonant inelastic X-ray scattering (RIXS) spectroscopy at the cobalt L-edge. The resulting cobalt 2p partial-fluorescence-yield (PFY) X-ray absorption (XA) spectrum, integrated from RIXS spectra, is simulated for various possible spi...
Serum aluminium and cobalt levels after ceramic-on-ceramic and metal-on-metal total hip replacement.
In a randomised study, 28 patients with a mean age of 62.2 years (32 to 81) with osteoarthritis or avascular necrosis of the hip received either a ceramic-on-ceramic or a metal-on-metal total hip replacement. Apart from the liners the acetabular and femoral components were made of Ti-Al-Nb alloy. The serum aluminium and cobalt levels were measured before, and at one year after surgery. The 15 p...
OVER the last several years the Department of Chemical Engineering of Monash University has been studying the general problem of mineral beneficiation of cobalt minerals. As part of the investigation, samples were obtained from the cobalt-mineralized area around Mount Cobalt, which is situated some 11o km south of Cloncurry in north-west Queensland, Australia. The geology of the area has been d...
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