Utilisation of Mineral Slimes and Industrial Waste by Electro Flotation and Selective Flocculation.

Electroflotation and selective flocculation or the combination of both appear to be potential techniques for the beneficiation of low grade mineral slimes and fines generated during mining, milling and other metallurgical operations. Considering the hydrodynamics of flotation process, electroflotation was proved to be an effective and viable technique to separate organic suspending particulate matter generated from leather, textile, metallurgical, oil refinery and food processing plants. Electroflotation is advantageous to process sulphide minerals and minerals that undergo surface changes when exposed to electrolytic oxygen and hydrogen. Adsorption of oxygen, liberated from the anode leads to the formation of elemental sulphur on the surface of the particles. Elemental sulphur thus formed under controlled oxidation enhances the hydrophobicity. Continuous liberation of H+ and OH- leads to drastic changes in the pH of the pulp. Hence, electroflotation technique is more disadvantageous where pH is a critical parameter. Also part of the collector will be either destroyed or dissociated under the influence of pH, electrolytic bubbles and oxidation-reduction environment changes. Selective flocculation of minerals using polymers followed by anyone of the separation techniques such as, flotation, elutriation, filtration, etc. offers considerable promise for processing non-precious oxide minerals. Natural and synthetic high molecular weight polymers have been successfully used as flocculants. Lack of desired specificity is the major set back in this process. However, specificity can be introduced by incorporating active groups in the polymers. Though there is enough literature on selective flocculation of synthetic mineral mixtures, reports on the flocculation of multi-component natural ores are scant. Further, it is generally observed that the prediction of selective flocculation on the basis of results obtained from single mineral tests fairly agrees with synthetic mineral mixtures but rarely on natural systems

Assessing the Impacts of Climate Change on Crop Yields in Different Agro-climatic Zones of India

The study attempts to estimate and predict climate impact on crop yields using future temperature projections under two climate emissions scenarios of RCP 4.5 and 8.5 for three different time periods (2030s, 2050s and 2080s) across Agro-climatic zones (ACZ) of India. During the period 1966-2011, a significant rise was observed in both the annual mean maximum and minimum temperature across ACZs. Rainfall recorded an annual decline in Himalayan Regions and Gangetic Plains and a rise in Coastal Regions, Plateau & Hills and Western Dry Region. Our results showed high heterogeneity in climate impact on kharif and rabi crop yields (with both negative and positive estimates) across ACZs. It was found that rainfall had a positive effect on most of crop yields, but was not sufficient enough to counterbalance the impact of temperature. Changes in crop yield were more pronounced for higher emission scenario of RCP 8.5. Thus, it was evident that the relative impacts of climate change and the associated vulnerability vary by ACZs, hence comprehensive crop and region-specific adaptation measures should be emphasized that helps in enhancing resilience of agricultural system in short to medium term

Ficus racemosa Stem Bark Extract: A Potent Antioxidant and a Probable Natural Radioprotector

Ethanol extract (FRE) and water extract (FRW) of Ficus racemosa (family: Moraceae) were subjected to free radical scavenging both by steady state and time resolved methods such as nanosecond pulse radiolysis and stopped-flow spectrophotometric analyses. FRE exhibited significantly higher steady state antioxidant activity than FRW. FRE exhibited concentration dependent DPPH, ABTS•−, hydroxyl radical and superoxide radical scavenging and inhibition of lipid peroxidation with IC50 comparable with tested standard compounds. In vitro radioprotective potential of FRE was studied using micronucleus assay in irradiated Chinese hamster lung fibroblast cells (V79). Pretreatment with different doses of FRE 1h prior to 2 Gy γ-radiation resulted in a significant (P < 0.001) decrease in the percentage of micronucleated binuclear V79 cells. Maximum radioprotection was observed at 20 μg/ml of FRE. The radioprotection was found to be significant (P < 0.01) when cells were treated with optimum dose of FRE (20 μg/ml) 1 h prior to 0.5, 1, 2, 3 and 4 Gy γ-irradiation compared to the respective radiation controls. The cytokinesis-block proliferative index indicated that FRE does not alter radiation induced cell cycle delay. Based on all these results we conclude that the ethanol extract of F. racemosa acts as a potent antioxidant and a probable radioprotector

Jellyfish as an export commodity

Recently, jellyfish blooms have been reported with increased frequency from several parts of the world and it has been suggested that this phenomenon might be related to over-fishing and other human activities that are driving marine ecosystems off balance. It has contributed to the formulation of the “fishing down the food chain” hypothesis, which is based on the assumption that the reduction in large species marine predator populations is promoting the growth of organisms from lower levels of the food chain. Rising sea temperature is also considered as a reason for the occurrence of jellyfish fishery

Health seeking behavior acceptability of available health facilities and knowledge about tuberculosis in a tribal area

A study was undertaken among the tribals living in Buttayagudem Mandal consisting of 53 villages in West Godavari district of Andhra Pradesh to study their health seeking behaviour, acceptability of available health facilities and knowledge about tuberculosis. Information was also obtained on their practices to get relief from illness and type of health facilities used. In all, 429 households belonging to 34 villages were selected at random and the heads of these households or the next responsible persons were interviewed. A total of 189 (44%) had heard of tuberculosis and of these, 72 (38%) attributed it to tubercle bacilli. A majority of the tribals were in favour of modern medicine and accepted the available health facilities

Alteration characteristics of illmenites from south India

Two different placer samples from the Navaladi and Surungudi area of Teri, Tamilnadu. in southern India. were collected and characterized in terms of their heavy mineral content. Mineralogical analysis on both the samples revealed the presence of high amounts of garnet and ilmenite. The alteration characteristics of ilmenite from these deposits were investigated by optical and electron probe microanalysis. Optical microscopic studies revealed that the alteration of ilmenite was seen to proceed along grain boundaries and/or fractures resulting in an amorphous to crypto- or microcrystalline mass resembling leucoxene. The alteration is in the nascent stage. Mineral chemistry by electron probe micro-analysis revealed the enrichment of Ti02, MgO, A1203•Cr203. Si02, V205 and Na20 in the altered products and loss of iron oxide and manganese oxide from the ilmenite grains during weathering leading to the formation of leucoxene. Similarly EPMA studies on garnet indicated that it is of the almandine variety. This study reveals that the alteration of ilmenite by weathering leads to unstable phases, with complex elemental distribution patterns. The physico-chemical characteristics of the mineral and, in turn, the down-stream metallurgical processing are affected by such alteration processes

Major and minor fisheries harbours of India. 8. Fisherries harbours along the coasts of North Andhra Pradesh, Orissa and West Bengal

The present account gives information about the three major and five minor fisheries harbours along the coasts of north Andhra Pradesh, Orissa and West Benga