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...

INTRODUCTION This survey aims at proposing reference values of metals in the hair, in the copper-belt (Province of Katanga). MATERIALS AND METHODS We ran a descriptive study, in an etiologic perspective, on a sample of non-industrial population, constituted by students of the University of Lubumbashi, healthy and without medical treatment (n  = 109). Hair samples were analyzed by Inductively ...

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...

An inspection of the active site region of metallo-enzymes leads to two conclusions. (i) Individual attacking groups usually have uncommon physical properties. (ii) The active site region is cooperatively linked with a large part of the enzyme. Such an interaction is common to heterogeneous catalysts but is absent in homogeneous catalysts. It is concluded that the energetics of catalysis requir...

Bbstract Recent developments involving polymer-supported metal complexes as catalysts in oxidation reactions, using dioxygen, hydrogen peroxide, alkyl hydroperoxides, hypochlorite anion and iodosobenzene as oxidants are reviewed. binding of dioxygen, and in catalysis, along with the structurally closely related metallo-phthalocyanines, oxidative polymerization catalysed by polymer-supported cop...

We explore how the atomic-scale structural and chemical properties of an oxide-supported monolayer (ML) catalyst are related to catalytic behavior. This case study is for vanadium oxide deposited on a rutile α-TiO2(110) single-crystal surface by atomic layer deposition (ALD) undergoing a redox reaction cycle in the oxidative dehydrogenation (ODH) of cyclohexane. For measurements that require a ...

Nanostructured vanadia model catalysts, i.e. highly dispersed vanadium oxide supported on mesoporous silica SBA-15 (VOx/SBA-15), were prepared. The mechanism for the synthesis of VOx/SBA-15 was elucidated by detailed characterization of the individual synthesis steps using XPS and vibrational spectrocopy. The resulting surface vanadium oxide species (0 – 2.3 V/nm), grafted on the inner pores of...