Structurally well-defined bimetallic titanium(IV) (salen) and monometallic vanadium(V) (salen) complexes have been used as catalysts for the asymmetric addition of trimethylsilyl cyanide to β-nitroalkenes to produce chiral nitronitriles with ee values in the range of 79-89 % and conversions up to 100 % at 0 °C. The reaction conditions (solvent, temperature, time and vanadium complex counter-ion...

The neutronics activities for SPPS included the determination of the blanket dimensions that provide tritium self-sufficiency, radiation damage to the structural materials, lifetime of the in-vessel components, radiation level at the superconducting magnets, and shielding requirements for magnet protection. The neutron wall loading varies in both poloidal and toroidal directions. For an average...

BiVO4 has shown great potential as a semiconductor photoanode for solar water splitting. Significant improvements made during recent years allowed researchers to obtain a photocurrent density of up to 4.0 mA cm(-2) (AM1.5 sunlight illumination, 1.23 VRHE bias). For further improvements of the BiVO4 photoelectrodes, a deep understanding of the processes occurring at the BiVO4-H2O interface is cr...

Notch deformation behaviour under monotonic and cyclic loading conditions was investigated using circumferentially notched round bar and double-notched flat plate geometries, each with two different notch concentration factors. Notch strains for the double-notched plate geometry were measured with the use of miniature strain gauges bonded to specimens made of a vanadium-based microalloyed steel...

Vanadium is the 22 most abundant element in the earth’s crust with an average concentration of 100 ppm. It exists in oxidation states ranging from 2to 5+ with 3+, 4+, and 5+ being the most common oxidation states. Vanadium is primarily used in the production of rust-resistant, spring, and high-speed tool steels; vanadium pentoxide is used in ceramics. Vanadium is released to the environment by ...

Vanadium is an important metal used almost exclusively in ferrous and non-ferrous alloys due to its physicochemical and mechanical properties such as grain refinement, high tensile strength, hardness and fatigue resistance; it has a wide range of uses in the metallurgical and chemical sectors [1–3]. There are mainly three kinds of raw materials, bone coal, vanadium slag and waste vanadium catal...

Vanadium (CAS No. 7440-62-2) is an element that exists in a number of oxidation states ranging from -1 to +5 and can be found in various locales around the world. Absorption of vanadium from the gastrointestinal tract is poor and most ingested vanadium is typically converted to vanadyl. Excretion of absorbed vanadium is primarily via urine while unabsorbed vanadium is mainly eliminated in feces...

A sensitive and simultaneous spectrophotometric flow injection method for the determination of vanadium(IV) and vanadium(V) is proposed. The method is based on the effect of ligands such as 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) and diphosphate on the conditional redox potential of iron(III)/iron(II) system. A four-channel flow system is assembled. In this flow system, diluted hydrochloric...

The discovery of high levels of vanadium-containing compounds in ascidian blood cells goes back to 1911. Ascidians, which are also known as tunicates or sea squirts, belong to a subphylum of the Chordata, between the vertebrates and invertebrates. This discovery attracted the attention of an interdisciplinary group of chemists, physiologists, and biochemists, in part because of interest in the ...