Cemented tungsten carbides are composed of a hard tungsten carbide (WC) phase held together by a soft, ductile binder phase, typically cobalt (Co). This study examines the role of the binder composition and content on the Knoop hardness at quasi-static and dynamic strain rates. Seven different t...

Tungsten carbide (WC) has been found to have higher resistance to plasma-induced thermal-shock compared to rolled tungsten. The electron beam device JUDITH 1 was used to simulate likely thermal shock conditions induced by edge localised modes and plasma disruptions. Loading conditions of 100–10...

The dissimilar antibiotics saramycetin and prasinomycin are capable of self-association in aqueous solvents between pH 3 and 12. Saramycetin, with a monomeric molecular weight (M.W.) of approximately 2,100 daltons, forms a 55,000-dalton aggregate. A 1,050-dalton fragment of saramycetin, isolated...

The molecular weight of the antibiotic saramycetin was determined as 2100 by two ultracentrifugal methods: (a) approach to sedimentation equilibrium and (b) combination of the zero concentration diffusion constant (D20 = 34 × 10−7 cm.2 sec.−1) with the zero concentration sedimentation constant ...

A mechanism for modelling the growth of faceted primary M7C3 needles during solidification of chromium carbide overlays is presented for the first time. In contrast with existing models that consider diffusion-controlled growth over the length of the needle, this work disaggregates the flow of s...

In this work, we report the first observation of novel nanocomposite thin films consisting of nanocrystalline chromium embedded in an amorphous chromium carbide matrix (nc-Cr/a-CrC) with relatively high hardness (∼22,3 GPa) and ultra low nanowear.The films were deposited onto silicon substrates...

Chromium carbide nanocomposites were in situ synthesized by combing solution combustion synthesis method and carbothermal reduction for the first time. A homogeneous precursor (amorphous chromium oxide and carbon) was fabricated by solution combustion synthesis method using glucose, chromium nit...

In the current study, the surface of AISI D2 steel was coated with the powder blends of ferro-vanadium (Fe-V) and ferro-chromium (Fe-Cr). The coatings were performed using a thermo-reactive diffusion (TRD) treatment by the pack cementation method at three different temperatures (900 °C, 1000 °...

The nanoparticles of vanadium, niobium, and tantalum carbides were synthesized by a mechanically induced magnesiothermic combustion in the separate Mg/V2O5/C, Mg/Nb2O5/C, and Mg/Ta2O5/C systems. Initial materials in these systems ignited after short milling times of 10, 10, and 23 min, respectiv...

The growth of vanadium carbide reinforced iron substrate surface compound layers are investigated, where the compound coatings were fabricated by in situ synthesis process at 950 °C, 1000 °C and 1050 °C in 1–5 h, respectively. A detailed characterization about the microstructural change of c...

Polymer electrolyte membranes based on organic – inorganic nanocomposites consisting of chitosan and silica supported silicotungstic acid (IHPA) are developed using simple solution casting technique. Compared to pristine chitosan membranes, IHPA incorporated membranes exhibit higher thermal, me...

Heteropoly acids have attracted increasing attentions in oxidative desulfurization (ODS) field, but the solubility and low surface area hindered their applications. Moreover, bulk silicotungstic acid (HSiW) was less researched, owing to its relative lower activity. Herein, a layered-structure he...

The gas phase dehydration of glycerol to acrolein over a series of supported silicotungstic acid (HSiW) on zirconia (10HZ, 20HZ, 30HZ and 40HZ) has been investigated. The catalysts were characterized by temperature programmed desorption, nitrogen adsorption–desorption, thermogravimetric analysi...

A single-stage synthesis of isoprene from methyl tertiary-butyl ether (MTBE) and formalin in an organic-aqueous two-phase system were studied by using Cs-exchanged silicotungstic acid catalysts (CsXH4-XSiW12O40, abbreviated as CsX-STA). The CsX-STA catalysts (x = 2.0, 2.5, 3.0, and 3.5) were pre...

A novel heterogeneous photocatalyst CaxH4-xSi4W12O40/Ca2Ta2O7 was prepared by planting silicotungstic acid on the surface of calcium tantalate. The materials are characterized by X-ray diffraction (XRD), scanning electron microspectroscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier t...

The present work elucidated the precipitants effect of pure CeO2 on the activity of silicotungstic acid supported on CeO2 catalysts toward NOx reduction. The results implied that the silicotungstic acid doped CeO2 prepared by the NH3·H2O precipitant showed the best SCR performance and nearly 10...

Condensation of various isatins with heteroaromatics (indoles and pyrrole) has been carried out in the presence of catalytic amount of silicotungstic acid (STA) at room temperature to form their corresponding 3,3-bis(indolyl)- and 3,3-bis(2-pyrrolyl)oxindoles. The mechanistic aspects of the reac...

In this work, the influence of silicotungstic acid concentration on the diphenylamine (DPA) electropolymerization in the absence and the presence of reduced graphene oxide (RGO) is studied. The optical properties of the composites based on polydiphenylamine (PDPA) doped with the H4SiW12O40 heter...

A series of silicotungstic acid modified CeO2 (SC-x, x represents the pH value of solution that is used for the preparation of catalysts) were prepared for the selective catalytic reduction (SCR) of NOx with NH3. SC-9 showed the best catalytic activity among the samples. The monodentate nitrate,...

Spiramycin is a widely used macrolide antibiotic and exists at high concentration in production wastewater. A thermal-acid hydrolytic pretreatment using silicotungstic acid (STA) under microwave (MW) irradiation was suggested to mitigate spiramycin from production wastewater. Positive correlatio...