458 research outputs found
PICES/ICES collaborative research initiative: Toward regional to global measurements and comparisons of zooplankton production using existing data sets
Characterisation and Response to Beneficiation of Ferruginous Chromite Ores
Sukinda-Nausahi belt of Orissa, represent about 90% of the Indian Chromite ore reserves. These ores are later-itic type in nature resulted by weathering of ultrabasic rocks, Metallurgical industries consume maximum chromite ores- around 50% followed by refractory and chemical indu-stries which consume about 35% and 15% respectively. The utility pattern of chromite in industries is varying greatly. The variation in the demand could be due to lim-ited market for medium and low grade chromite. Hence it is necessary to improve the chromium content for better util-isation and conservation of available resources
Kinetics of thermal decomposition of some metal oxalates
The thermal decomposition kinetics of oxalates of ZnII, NiII and ThIV have been studied in air by isothermal and non-isothermal thermogravimetry. The isothermal kinetic results suggest that the mechanism of decomposition of the zinc compound involves rapid nucleation followed by two dimensional growth in the acceleratory region, while in the case of thorium oxalate, the initial nucleation occurs by a chain mechanism on the surface of the reactant followed by the growth of the product from the surface towards the interior. The results on nickel oxalate could not be interpreted in an unambiguous manner. The activation energy and the frequency factor obtained from TG curves compare well with those obtained from the isothermal method. The activation energies for the dehydration of these oxalates have also been evaluated from the thermogravimetric curves
Dynamic response of ECAE-AZ31 magnesium under pressure shear
Lightweight and energy mitigation are considered the core characteristics required of any material system -subjected to impact loading conditions, and magnesium alloys represent potential materials for such systems. ECAE-AZ31, an Mg alloy system processed through Equal Channel Angular Extrusion (ECAE), is a particularly interesting candidate given its specific strength. We seek here to develop an understanding of its constitutive response at very high rates of loading. We perform an experimental investigation of the behavior of this material, at strain rates on the order of 105 s–1, using the high-strain-rate pressure-shear plate impact technique. We also present a brief description of the experimental setup and describe the diagnostic techniques used. Using the measured behavior and examination of the initial and deformed microstructures, we examine the influence of anisotropy and micromechanisms (twinning, dislocations) on the overall constitutive response. The goal is to parameterize such influences to incorporate them into a constitutive framework
Synthesis of 5:6:7-hydroxyflavones and their derivatives - Part I
This article does not have an abstract
Synthesis of 5:6:7-hydroxyflavones and their derivatives - Part II
This article does not have an abstract
Synthetic experiments in the benzopyrone series. Part X. Synthesis of carthamidin and iso-carthamidin
This article does not have an abstract
- …