Kinetics of hydrogen abstracting from proton donors by DPPH

The kinetics and energetics of the interaction of DPPH with a variety of hydroxylic compounds have been investigated by electronic and e.s.r. spectroscopy. Deuterium isotope effects on the kinetics have been examined. A model involving hydrogen bonded complexes has been suggested for the hydrogen abstraction reaction

Cardiorespiratory and Neuromuscular Effects of Freshwater Cyanophyte Anabena flosaquae in Rats

Anatoxin-a, recognised as a potent toxin warfare agent, is considered as a weapon of mass destruction due to its lethal anticholinesterase activity. The intravenous administration of cell-free extract of Anabena flosaquae UTEX-2383(anatoxin-a) produced a transient vasodepressor response followed by a sustained rise in blood pressure. The vasodepressor effect was potentiated by physostigmine and antagonised by atropine and bilateral vagotomy, suggesting the involvement of cholinergic system. On the contrary, the vasopressor response was antagonised by hexamethonium prazosin and hemicholinium-3, indicating that the toxin stimulates the sympathetic system through the release of catecholamines from nerve endings. Prolonged apnoea with attendant bronchoconstriction was observed corresponding to bradycardia and vasppressor response which remained unaltered by atropine while antagonised by bilateral vagotomy. The extract when administered intra-arterially did not modify the apnoea induced by veratridine; but phenyldiguanide potentiated the bronchoconstriction, indicating the involvement of pulmonary vagal afferents. The extract produced a dose- and time-dependent blockade of indirect muscle twitch recorded from gastrocnemius muscle. The neuromuscular blockade was potentiated by neostigmine but unaltered by DTC

Column flotation technology for the beneficiation of coking and non-coking coal fines

The importance of coal is bound to increase for the coming years with the growth of coal consuming industries. Power sector is the most potential consumer of the non-coking coal and for coking coal iron & steel sector remains the major consumer. In future, coal gasification which is successfully adopted in China, an advanced coal-based power generation technology has the potential to provide higher generating efficiency and can be adopted to efficiently burn India’s high-ash coals. In the present study investigations are carried out on coal fines for both coking and non coking coals by conventional and column flotation techniques to suit industrial applications. Coking coal sample is taken from Jamadoba area in Jharkhand and non-coking coal is drawn from coal belt in Central Coal Fields, Jharkhand. For both the coals detailed studies are in progress for optimizing the reagent consumption and to establish the feasibility of column flotation technology for producing low ash concentrates with reasonably high recoveries

Recovery of values from tailing ponds of iron ore washing plants

Most of the Iron ore washing plants set up in India in the earlier days consist of sizing of the ore by dry / wet screening, washing and classification by screw classifiers. In this classical approach, iron values were lost in the form of fines and utrafines into the tailing ponds as they had little commercial value in those days and accumulated in huge quantities over the years. As the high grade deposits are getting exhausted and the demand for high grade finer material for pellet making is ever increasing, focus is shifting towards recovering the values from the erstwhile tailing ponds by column flotation. This is also supposed to mitigate to certain extent the environmental problems caused by the ever expanding and unmanageable tailing dams. A case study is presented wherein a composite sample is prepared from samples drawn systematically from multi - locations in a sprawling tailing dam. Laboratory scale column flotation tests on this composite tailings sample, basically originating from two operating iron ore beneficiation plants of JSW Steel Ltd., one of the leading producers of steel in India, are found to be encouraging. De-sliming followed by reverse and cationic flotation tests using flotation column resulted in the concentrate of 61.88% Fe, 4.81% SiO2, 2.52% Al2O3 and 3.30% loss on ignition (LOI) from the tailings analysing 57.86% Fe, 7.10% SiO2, 3.52% Al2O3 and 6.14% LOI with 52% weight recovery. The causes for the quality improvement could be attributed to de-sliming of unliberated ultra fines of kaoline and hydrated iron oxides and their further reduction by efficient flotation process. The process and the cationic collector developed for this purpose are adopted in the new flotation plant created to treat these tailings

Beyond numbers, coverage and cost : adaptive governance for post-COVID-19 reforms in India

Crisis as an opportunity for change has been part of historical and development literature and is an oft-repeated theme. The Chinese word for crisis (危機), for example, consists of two symbols often characterised in popular literature as denoting ‘danger’ and ‘opportunity’.1 For India’s healthcare system, the COVID-19 crisis has highlighted the urgency of reform. We have learnt that no matter how long or how stringent a lockdown is, we cannot flatten the curve effectively, nor fairly, without a robust health system. In the pre-COVID-19 world, practitioners and policy-makers were gathering around the Universal Health Coverage (UHC) agenda that sought to expand the number of health services provided to the largest number of beneficiaries at the cheapest possible cost, constituting the three dimensions of UHC.2 This pandemic has made it clear that incremental progress along those three dimensions while necessary, is insufficient to move towards a health system that is responsive, resilient and fai

Classification of Ultra Fine Particles from Fly Ash

The annual generation of coal combustion residue in the country is 110 MT. The generation of coal combustion residue is expected to increase with ever increasing demand for power. Management of this solid waste has been a great concern to the nation. Most of the reports on utilization of coal combustion residue are limited to direct usage of the material or selective collection from ESP fields in the thermal power plants. In this connection several efforts are being made in the country to enhance its application as a replacement to cement, soil modifier, roads and embankments etc. Very little or no research attempts are made in understanding the appropriate compo-nents which results in beneficial properties and value added products. Fly ash in very fine size range exhibits spherical morphological characteristics and thus acts as good fillers in rubber and polymer compounds. However, recovery of this size material from the bulk is yet a challenge in the process industry as the material forms clusters at very fine sizes. The present study is an atte-mpt to beneficiate fly ash to obtain material with an average particle size around 5 microns. A cyclone separa-tor, which employs very high g* forces for separation of particles is employed for achieving the separation. At this high g* forces, the declustering of particles is observed. This technique has generated product with an average particle size (ds& between 4 to 8 microns. The results obtained at different test runs are discussed

Marine Meteorological Atlas of Tropical Indian Ocean

This report discusses the preparation of climatology from the data which is from the ship observations obtained from the Indian Meteorological Department (IMD) and Naval Operations Data Processing and Analysis Centre (NODPAC). Processing of these datasets, extraction of surface meteorological variables and SST (Sea surface temperature), the quality control (QC) procedures followed are discussed. The individual records of International Comprehensive Ocean-Atmosphere Dataset (ICOADS) and those obtained from IMD are compared and the unique records from IMD data are extracted. The enhancement in ICOADS climatology after adding the unique records from IMD data and NODPAC is checked. ICOADS dataset has been found to be self robust, as there is no much significant improvement in the climatology even after adding new records . Frequency distribution of the ICOADS dataset alone and after adding new records showed no much difference. Spatial correlation between ICOADS monthly climatology fields before and after adding the new records, is greater than 0.9 at all grid point

Eco Friendly and Cost-Effective Reagent for Coal Flotation

Conventionally, diesel in combination with a frother is used widely in flotation of coal fines. With the continuous price escalation of petroleum products and their negative impact on environment, attempts were made to formulate an eco-friendly single reagent to replace diesel-frother system without affecting the flotation performance. Laboratory flotation tests were carried out, on a coking coal sample from eastern India, that analyzed 25.67% ash and 53.97% fixed carbon using a series of reagents developed. Among them, the performance of Sokem 590C derived from a vegetable oil was found to be encouraging. Concentrate assaying 11.77% ash and 66.40% fixed carbon was obtained with yield of 56.57%. Moreover, the reagent is biodegradable and eco friendly. Based on favorable kinetics and encouraging test results, plant trials were conducted at a coal preparation plant and the superiority of this reagent was demonstrated

Single reagent for coal flotation

Froth flotation is widely used for the beneficiation of fine coal and collectors are important for the effective separation in flotation. Conventionally, diesel in combination with a commercial frother is used in most of the coal washeries. With the escalating costs of petroleum products and their negative impact on environment, attempts were made to formulate an eco-friendly single reagent to replace diesel-frother system without hindering the flotation process performance. NML-Madras Centre in collaboration with M/s Somu Organo Chem Pvt Ltd, has been working on the formulation and evaluation of flotation reagents. Laboratory flotation tests were carried out using series of single reagents on a coking coal sample from Jharia region in the eastern part of India with an ash content of 24.9%. The best among the single reagents, Sokem 590C, yielded a float of 56.57% at 13.97% ash in the bench scale laboratory test. Based on encouraging results of flotation tests and kinetics studies, plant trials were conducted at a coal preparation plant in eastern India. The results of plant trials using this single reagent, Sokem 590C, are highly encouraging and economical as compared to diesel-frother system and this single reagent is non-petroleum based and biodegradable

MaMeAT - A tool for visualizing marine meteorological data for Naval applications

This report discusses various functionalities of tool developed for use by Naval Operations Data Processing and Analysis Centre (NODPAC) a wing of Indian Navy. The data for this tool is obtained from the Indian Meteorological Department (IMD), Naval Operations Data Processing and Analysis Centre (NODPAC) and individual records of International Comprehensive Ocean-Atmosphere Dataset (ICOADS). These data sets are processed, quality controlled and merged to form a unique data set for enhancing the marine met climatology of Indian Ocean. The IMD and NODPAC data are compared with the unique records from COADS and duplicates are eliminated. With addition of around 12% unique records to ICOADS data, enhanced climatology is regenerated. With this base data, Graphic User Interface (GUI) based tool is build for visualizing parameters viz., SST, SLP, Wind, Relative Humidity, SSS and bathymetry. This tool has capability to generate climatology dynamically between any chosen periods apart from visualizing various plots which are useful for Navy while at sea. Also provision for adding newly observed marine met data is provided making this most robust tool for use by the Indian Navy