Search results for "Fischer"
showing 9 items of 19 documents
The fischer indole synthesis of 8-methyl-5-substituted-1-oxo-β-carbolines: A remarkable high yield of a [1,2]-methyl migration.
1991
Abstract A very unusual high yield of rearranged products (via methyl migration) has been obtained in the Fischer indole cyclization of the 3-(2,5-dimethyl phenylhydrazone) of 2,3-piperidine dione (6b). When a less activated aromatic ring is present in the phenylhydrazone 6, such a behaviour is not observed and cyclization occurs essentially without rearrangement.
Toxicological profile of cereulide, the Bacillus cereus emetic toxin, in functional assays with human, animal and bacterial cells
2007
International audience; Some strains of the endospore-forming bacterium Bacillus cereus produce a heat-stable ionophoric peptide, cereulide, of high human toxicity. We assessed cell toxicity of cereulide by measuring the toxicities of crude extracts of cereulide producing and non-producing strains of B. cereus, and of pure cereulide, using cells of human, animal and bacterial origins. Hepatic cell lines and boar sperm, with cytotoxicity and sperm motility, respectively, as the end points, were inhibited by <= 1 nM of cereulide present as B. cereus extract. RNA synthesis and cell proliferation in HepG2 cells was inhibited by 2 nM of cereulide. These toxic effects were explainable by the acti…
H2-TPR, XPS and TEM Study of the Reduction of Ru and Re promoted Co/γ-Al2O3, Co/TiO2 and Co/SiC Catalysts
2016
<p class="1Body">Effects of Ru and Re promoters on Co-CoO<sub>x </sub>catalysts supported on γ-Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub> and SiC were investigated to improve the understanding of the role of promoters of the active phase of Co-CoO<sub>x</sub>-Ru and Co-CoO<sub>x</sub>-Re. The influence of promoter addition on the composition and activity of the catalysts was characterized by several methods, such as H<sub>2</sub>-TPR, XPS, chemisorption and TEM. Furthermore, the role of support and metal-support interaction was especially studied and different support materials were compared.</p&g…
The role of nano-sized iron particles in slurry phase Fischer–Tropsch synthesis
2003
Abstract The slurry phase Fischer–Tropsch (F–T) activity of three α-Fe2O3-based materials, two unsupported nano-sized, NANOCAT (3 nm) and BASF (20–80 nm), and a supported micron-sized (32.5 μm ) UCI, are compared with respect to total hydrocarbon production from synthesis gas (H2/CO∼2/1) at 513 K. Low temperature Mossbauer spectra of the quenched slurry samples after 120 h on-line show that all three catalysts are essentially a mixture of oxide and carbide phases with magnetite (Fe3O4) being the dominant phase. TEM images of the quenched samples reveal unexpected particle characteristics. While both unsupported nano-sized materials essentially avoid expected agglomeration, the micron-sized …
Rutting analysis of different rubberised stone mastic asphalt mixtures: from binders to mixtures
2021
Stone Mastic Asphalt (SMA) has been broadly used on heavily trafficked roads and motorways in the UK due to its known stability and durability. In this study, several sets of SMA mixtures were produced using different rubberised bitumens, including a Fischer–Tropsch wax pre-treated rubberised bitumen. Properties associated with rutting were evaluated using both linear and nonlinear viscoelastic analyses, using different test methods such as the Strategic Highway Research Programme (SHRP), Shenoy rutting parameter, zero shear viscosity (ZSV) and multiple stress creep recovery (MSCR) tests. The rutting resistance of the resulting SMA mixtures was assessed using the Repeated Load Axial Test (R…
Superior Fischer-Tropsch performance of uniform cobalt nanoparticles deposited into mesoporous SiC
2020
Electrochemically-derived well-crystalline mesoporous silicon carbide (pSiC) was used as a host for cobalt nanoparticles to demonstrate superior catalytic performance during the CO hydrogenation according to Fischer-Tropsch. Colloidal Co nanoparticles (9 ± 0.4 nm) were prepared independently using colloidal recipes before incorporating them into pSiC and, for comparison purposes, into commercially available silica (Davisil) as well as foam-like MCF-17 supports. The Co/pSiC catalyst demonstrated the highest (per unit mass) catalytic activity of 117 µmol.g(CO)-1.g-1(Co).s-1 at 220 °C which was larger by about one order of magnitude as compared to both silica supported cobalt catalysts. Furthe…
Phospha-Fischer Carbenes: Synthesis, Structure, Bonding, and Reactions of Pd(0)− and Pt(0)−Phosphenium Complexes
2009
The analogy between cationic group 10 metal−phosphenium complexes and Fischer carbenes has been formalized through structural and reactivity studies and by energy decomposition analysis (EDA) of the M−P bond. The studied compounds were the three-coordinate, 16-electron species [(NHPMes)M(PPh3)2]OTf (M = Pt (1) and Pd (2); [NHPMes]+ is the N-heterocyclic phosphenium (NHP) cation, [tiebar above startPN(2,4,6-Me3-C6H2)CH2CH2tiebar above endN(2,4,6-Me3-C6H2)]+, OTf = trifluoromethanesulfonate); these were made by reaction of [NHPMes]OTf with M(PPh3)4. The metal−phosphenium bond in both compounds was dominated by metal-to-ligand π-donation. This differed from the M−C bonds in the analogous N-het…
A Hake-Type Theorem for Integrals with Respect to Abstract Derivation Bases in the Riesz Space Setting
2015
Abstract A Kurzweil-Henstock type integral with respect to an abstract derivation basis in a topological measure space, for Riesz space-valued functions, is studied. A Hake-type theorem is proved for this integral, by using technical properties of Riesz spaces.
From 2009 to 1929: Lessons from Fisher, Keynes and Minsky,
2010
International audience