Search results for "copper"
showing 10 items of 3029 documents
Cyclic Sulfoximine and Sulfonimidamide Derivatives by Copper‐Catalyzed Cross‐Coupling Reactions with Elemental Sulfur
2023
Copper-catalyzed cross-coupling reactions of α-bromoaryl NH-sulfoximines with elemental sulfur lead to benzo[d][1,3,2]dithiazole-1-oxides, which represent a new class of three-dimensional heterocycles. The reactions proceed under mild conditions showing good functional group and heterocycle tolerance. By imination/oxidation, the initial cross-coupling products can be converted to unprecedented cyclic sulfonimidamides derivatives. Furthermore, a seven-membered heterocycle was obtained by a ruthenium-catalyzed ring-expansion with ethyl propiolate. peerReviewed
Augmentation of weld penetration by flux assisted TIG welding and its distinct variants for oxygen free copper
2021
Abstract A comparative study to investigate the influences of single component fluxes on the depth-to-width ratio (DWR) of oxygen free copper was carried out with novel variants of tungsten inert gas (TIG) welding namely Activated TIG (A-TIG), Flux Bounded TIG (FB-TIG) and Flux Zoned TIG (FB-TIG) processes. The experiments to identify the fluxes delivering the higher DWRs in A-TIG welding among thirteen distinct fluxes were followed by the trials with FB-TIG and FZ-TIG employing those identified DWR fluxes. The fluxes which outperformed with all the techniques were MoO3 & MgO. Reversed Marangoni and arc constriction mechanisms were perceived to be opt for such an increase in DWR. Metallurgi…
New Insight on Archaeological Metal Finds, Nails and Lead Sheathings of the Punic Ship from Battle of the Egadi Islands
2023
The wreck of the Punic ship exhibited at the Archaeological Park of Lilybaeum (Marsala, Italy) is a unique example in the world. In this paper, the investigation of some metal finds (30 nails and 3 fragments of sheathings) belonging to the wreck of the Punic ship is reported. Portable X-ray fluorescence and Raman spectroscopy allowed us to identify the elements and compounds constituting them and make some deductions about their composition. X-ray diffractometry, polarised optical microscopy and scanning electron microscopy of the collected micro-samples allowed us to explain the degradation that occurred in the underwater environment.
Diuron mobility through vineyard soils contaminated with copper
2005
International audience; The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17–509 mg kg−1 total Cu (field-applied). Grass was plant…
An unusual magnetic response in a π-stacked 66-dia net structure of [4 + 2] copper(II) cubane
2015
A phenoxo bridged antiferromagnetic copper(II) cubane, features a π-stacked 66 -dia net framework, which creates long range ferromagnetic ordering, as evidenced from a coercivity maximum (~2000 Oe) at 20K with very unusual saturation magnetization. peerReviewed
Antifouling Systems Based on a Polyhedral Oligomeric Silsesquioxane-Based Hexyl Imidazolium Salt Adsorbed on Copper Nanoparticles Supported on Titania
2023
The reaction of octakis(3-chloropropyl)octasilsesquioxane with four equivalents of 1-hexylimidazole or 1-decylimidazole gave two products labelled as HQ-POSS (hexyl-imidazolium quaternized POSS) and DQ-POSS (decyl-imidazolium quaternized POSS) as regioisomer mixtures. An investigation of the biological activity of these two compounds revealed the higher antimicrobial performances of HQ-POSS against Gram-positive and Gram-negative microorganisms, proving its broad-spectrum activity. Due to its very viscous nature, HQ-POSS was adsorbed in variable amounts on the surface of biologically active oxides to gain advantages regarding the expendability of such formulations from an applicative perspe…
Stimuli-responsive bile acid-based metallogels forming in aqueous media
2015
Abstract The synthesis and gelation properties of a picolinic acid conjugated bile acid derivative in the presence of metal salts along with the stimuli-responsiveness of the systems are reported. The gels are formed in the presence of Cu 2+ ions in the solvent systems composed of 30–50% of organic solvent (MeOH, acetonitrile, or acetone) in water. The gels respond to various stimuli: they can be formed upon sonication or shaking, and their gel–sol transformation can be triggered by a variety of chemical species. NMR, MS, and SEM techniques are exploited in order to gain a deeper insight on the self-assembled systems.
D-penicillamine in Wilson's disease presenting as acute liver failure with hemolysis.
1982
Wilson's disease in a young woman presenting with an acute course is described. The clinical manifestations were fulminant hepatic failure associated with marked intravascular hemolysis. Immediate D-penicillamine and high-dose steroid therapy did not influence the course of the disease. Necropsy revealed an increased hepatic copper content and cirrhosis with extensive necrosis of the liver.
Spontanfrakturen im Säuglingsalter durch Kupfermangel
1989
A preterm infant of 25 weeks’ gestation developed at 4 months of age an “impressed” fracture of the right femur. In another preterm infant of 27 weeks’ gestation, multiple fractures of the radius and metacarpalia were observed at age 5 months. Also a full term twin showed multiple rib fractures. Additional radiological findings were: generalized skeletal osteopenia, cupping and fraying of the metaphyses of the long bones, and subperiosteal new bone formation. Further symptoms were repeated apnoic attacks, anemia, neutropenia, and low serum levels of both copper and coeruloplasmin. Alimentary copper deficiency was diagnosed and oral copper substitution (CuCl2 1,2–2,0 µmol/kg/d) initiated. Th…
Skelettveränderungen bei Frühgeborenen mit Kupfermangel
1991
We describe 5 preterm infants (25th to 30th week of gestation) suffering from alimentary copper deficiency. The diagnosis was confirmed by low serum copper and caeruloplasmin concentrations. Characteristic clinical findings were repeated apnoeic attacks, hypopigmentation of skin and hair, anaemia, neutropenia and leucopenia refractory to other therapy, as well as increasing serum alkaline phosphatase activity in the first month of life. Starting in the 3rd to 12th week of life the radiographic findings were general skeletal osteoporosis and retardation, metaphyseal radiodense lines, irregular metaphyses, cupping and spurring of the metaphyses, followed by multiple fractures and subperiostea…