Explosions of carbon black and propane hybrid mixtures

Explosions of hybrid mixtures, i.e. mixtures containing more than one combustible phase, are not well understood. Most studies in this area involve mixtures of common dusts and gases, such as coal and methane, or polyethylene and ethylene. The present work focuses on explosions of carbon black particles, i.e. almost pure carbon with a very low content of volatiles: this makes the process of explosion less intense. However, addition of some quantities of combustible gases (here: propane) may sustain combustion processes. Another important issue is the fact that the carbon black particles are smaller in size than most dusts encountered in the process industry. The experiments were carried out in a 20-L explosion vessel and the analysis of the results focuses on the maximum explosion pressures and the maximum rates of pressure rise as a function of carbon black and propane concentrations. In addition, some samples of unburnt dust were collected and analysed with a scanning electron microscope and with thermo-gravimetric analysis.     

Studies on Merops orientalis Latham 1801 with special reference to its population in Mayiladuthurai, Tamil Nadu

Role of habitat-structure and climatic factors in the population dynamics of the small green bee-eater Merops orientalis was evaluated in three habitats viz., agricultural lands, river banks and human habitations during 1991-1993. The river banks supported relatively high population of bee-eaters (157/Km2) followed by the agricultural lands (101/Km2) and human habitations (58/Km2). Bee-eater populations showed year-wise variations in river banks and human habitations having high values during 1992 (123/Km2) and 1993 (43/Km2) respectively. Agricultural lands showed a significantly low mean density in 1991 than other years. Seasonal variations in the bee-eater densities among the habitats were also recorded. Vegetation structure, food (insects) availability, climatic conditions and human disturbance were the casual factors for variations in bee-eater populations.     

Performance evaluation of lean sustainable systems using adaptive neuro fuzzy inference system: a case study

The modern manufacturing organisations have been adopting both lean and sustainable manufacturing paradigms to survive in the competitive environment. Lean and sustainable strategies aim at achieving productivity improvement by streamlined processes and waste elimination. The performance of such integrated lean sustainable system has to be assessed to ensure whether the strategic objectives are in line with customer value and to identify improvement opportunities that enable and enhance the competitive advantage of an integrated lean sustainable system. This paper presents the formulation of conceptual performance evaluation model to assess lean sustainable systems. Appropriate performance indicators have been identified and adaptive neuro fuzzy inference system approach is used to evaluate lean sustainability. A case of automotive component manufacturing firm in Indian scenario is exemplified. Based on the evaluation, lean sustainability index was computed and the firm was found to be ‘Averagely Lean Sustainable’. Further improvement actions to enhance the lean sustainable performance were planned and implemented. The developed performance evaluation model is capable of effectively evaluating the lean sustainable performance of manufacturing firms and has more practical relevance.     

A review on calcium-rich industrial wastes: a sustainable source of raw materials in India for civil infrastructure—opportunities and challenges to bond circular economy

Journal of Material Cycles and Waste Management - This study provides an overview of calcium rich industrial wastes usage in construction materials, their properties and different applications...     

Electrochemical destruction of p-chlorophenol and p-nitrophenol -- Influence of surfactants and anode materials

The electrochemical oxidative removal of p-chlorophenol and p-nitrophenol was studied by cyclic voltammetry (CV) and constant current electrolysis on commercially available graphite and titanium substrate insoluble anodes (TSIA). The effect of cationic cetyl trimethylammonium bromide (CTAB), anionic sodium dodecyl sulphate (SDS) and non-ionic polyoxyethylene(23)lauryl ether (Brij-35) surfactants, which prevent adherent film formation on the electrode surface were also studied. CV experiments indicate that p-chlorophenol exhibits a relatively higher tendency for film formation on graphite and that sodium chloride is a better medium for the destruction of phenols. The electrochemical oxidation of phenols under galvanostatic conditions in chloride medium with CTAB enhanced the detoxification process with significantly lower fouling effects on TSIA. The surfactants, however, did not improve phenol removal on graphite under identical experimental conditions. A charge of 2.5F per mol was found to be sufficient to achieve 44-48% removal of phenol on both the electrodes in the absence of the surfactants. A 55-65% removal was achieved in the presence of the cationic surfactant on the TSIA electrode. Phenol was removed as a low molecular weight polymer (MW approximately 4450).     

Habitat use pattern of tidal mud and sand flats by shorebirds (charadriiformes) wintering in southern India

Habitat use pattern and status of shorebirds in southern India were investigated in six tidal flats comprising three mudflats and three sand flats on the east coast of southern India. Totally, 7757 shorebirds belonging to 21 species were recorded during September 2000–March 2002. The birds preferred mudflats over sand flats. Density, diversity and richness of shorebirds were relatively higher in tidal flats, especially in mudflats. The shorebirds preferred mudflats over sand flats as stopover sites and sites for refueling the required energy during migration. Rhythmic changes in tidal pattern also influenced the allochthonous nutrients and prey species, which also attracted the migratory shorebirds. However, the abundance of shorebirds with reference to tidal flats *season*tide and habitats*seasons * tide had strong variations (P < 0.001). During migratory season, bird density, diversity and species richness were observed higher than in other seasons.     

Assessing the recycling potential of glass fibre reinforced plastic waste in concrete and cement composites

At present glass fibre reinforced plastic (GRP) waste recycling worldwide is very limited due to its intrinsic thermoset properties, lack of characterisation data and non availability of viable recycling and recovery routes. In the present study, efforts were made to recycle GRP waste powder and fibre in concrete and cement composites and assess its quality to comply with the British standards for use in construction applications. Results revealed that the mean compressive strength of concrete composites using 5%–50% GRP waste powder under water curing varied from 37 N/mm² to 19 N/mm². Increase in the concentration of GRP waste decreased the compressive strength. However, increase in curing duration (14–180 days) resulted in improving the compressive strength of concrete with 5% GRP application to 45.75 N/mm². Moreover, the density of concrete with 50% GRP waste was reduced by about 12% as compared to the control sample. The bending strength in terms of modules of rupture (MOR) of 12 mm thickness cement composites developed using 5% GRP waste fibre attained 16.5 N/mm². The findings of this work pave the way for further GRP waste recycling in precast construction products for use in various applications.     

Studies on nest construction and nest microclimate of the Baya weaver, Ploceus philippinus (Linn.)

The nest construction pattern at different stages of nest and variations in the nest microclimate, i.e., temperature and light intensity were assessed in different nests of Baya weaver (Ploceus philippinus) between November 2002 and March 2003 in Nagapattinam and Tiruvarur District of Tamil Nadu, India. The Baya weaver constructed nests in palm (Borassus flabellifer), coconut (Cocos nucifera) and date palm trees (Phoneix psuilla) and majority of the nests were found in the solitary palm. The male bird only involved in the construction and took 18 days to construct a single nest. The birds spent different amount of working hours (in terms of days) for completing various stages of nests viz., wad, ring and helmet stage and in which the 'helmet stage took a maximum of eight days. Furthermore, totally eight active nests were selected and once in a week the variations in the nest microclimate was investigated with reference to atmospheric temperature and light intensity (two active nests) across day throughout the study period. The mean temperature of the nests ranged from 25 degrees C to 29 degrees C and light intensity varied between 25 Lux and 625 Lux. The analysis of variance (ANOVA and ANCOVA) indicated that the nest microclimate varied among the nests in different hr of a day     

Characteristics variation of coal combustion residues in an Indian ash pond.

Coal-fired power plants all over the world are cited as one of the major sources that generate huge quantities of coal combustion residues (CCRs) as solid wastes. Most frequently CCRs are collected through electrostatic precipitators, mixed with bottom ash by hydraulic systems and deposited in ash ponds. The quality of the CCRs at different locations in one of the ash ponds in Central India was evaluated to understand the variation in characteristics with a view to effective utilization. Results revealed that the presence of fine particles (< 50 mocrom) increased with increasing distance from the ash slurry inlet zone in the ash pond. Wide variations in the bulk density (800-980 kg m(-3)), porosity (45-57%) and water-holding capacity (57.5-75.7%) of CCRs were recorded. With increasing distance the pH of the CCRs decreased (from 9.0 to 8.2) and electrical conductivity increased (from 0.25 to 0.65 dS m(-3)). The presence of almost all the heavy metals in CCRs exhibited an increase with distance from the ash slurry discharge zone due to the increase in surface area (from 0.1038 to 2.3076 m2 g(-1)) of CCRs particles. The present paper describes the variation of characteristics of CCRs deposited in the ash pond and their potential applications.     

The Freshwater Mussel Parreysia Favidens (Benson) As A Biological Indicator of Polonium - 210 in A Riverine System

The concentration of ²¹⁰Po, an alpha emitter from the natural uranium series was measured in the soft tissues (total), shell, and different organs - digestive glands, gills, mantle and foot - of the freshwater mussel, Parreysia favidens (Benson), collected from the river Kaveri, at Tiruchirapalli in South India. the analyses were made in three size groups based on shell length (Group 1: 2-4 cm; Group 2: 4-5 cm; Group 3: 5-6 cm). the soft tissues of the mussel accumulated higher concentrations of ²¹⁰Po (74.0-125.5 Bq kg^-1 fresh) than the shell (2.9-3.9 Bq kg^-1 fresh). Further, younger mussels (1 group) showed higher concentrations (125.5+2.0 Bq kg^-1 fresh) in total soft tissues than older ones (III Group) (74.0+1.6 Bq kg^-1 fresh); concentration factors were 1.59x 10⁵ in I group and 9.37 × 10⁴ in III group. the ²¹⁰Po was observed to be non-uniformly distributed among the internal organs, which maintained the following descending order with reference to ²¹⁰Po accumulation: digestive glands, ranging from 286.2+3.5 Bq kg^-1 fresh to 43+1.3 Bq kg^-1 fresh. the concentration of ²¹⁰Po in the mussels was distinctly higher than that in the grass, Echinochloa colonum (J. Koenig), and carp, Cirrhinus cirrhosa (Bloch), from the same river. These data indicate that younger mussels could be used as an excellent biological indicator of ²¹⁰Po and among soft tissues, digestive glands are preferable to other tissues to monitor the distribution of ²¹⁰Po in the riverine system.