Influence of micro boron carbide particles on microstructure, mechanical properties, and dry sliding wear properties of an aluminium Al2214-B4C metal matrix composite

In this experimental research, an attempt is made to develop Al2214-B4C composite materials with reinforcement of micro boron carbide (B4C) (viz. 0, 1.5, 3, 4.5, and 6 wt.%) by using a novel liquid metallurgical stir casting technique with modified bottom pouring facilities and studying the microstructure, physical, mechanical, and dry sliding wear resistance responses. The microstructure of Al2214-B4C composite samples with varied boron carbide weight percentages was examined under an electronic scanning microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDX) device. The physical characteristics like density and porosity, mechanical strength, such as micro and macro hardness, yield and ultimate tensile strength, and sliding wear response were examined under variable experimental conditions. The experimental results of the Al2214-B4C composite revealed a decreased specific density with an increased weight percentage of boron carbide particles in the matrix and a homogeneous distribution of reinforced micro boron carbide particles in the Al2214 matrix. There was an appreciable improvement in mechanical properties and wear properties in composite materials as compared to an unreinforced aluminium alloy

Economic evaluation of composite culture practices of crab fattening and fish-shrimp farming in Kerala

The aquaculture industry in India is picking up rapidly in view of its high income and employment generating potential. Recently there has been a drastic reduction in the production of shrimps from our aquaculture fanns due to the outbreak of disease. The declining demand for shrimps in export market further induced our fanners to look for alternative lucrative farming practice

Growth of staghorn coral Acropora aspera (Dana) (Scleractinia: Acropridae) in relation to environmental factors at Kavaratti atoll (Lakshadweep Islands), India

Skeletal extension and calcification were measured over 2 years in branches of the staghorn coral Acropora aspera from a shallow-water si te. Correlations were made between growth parameters and environmental variables monitored over the same period. Calcification .varied significal)tly (9.4- 17.4 mg. 28d - ') than skeletal extension (3.1 -4.7 mm. 28d -') and unlike extension, it varied significantly between seasons with lowest values during southwest monsoon (June-September). Seasonal reduction in calcification was probably associated with the reduced availability oflight due to increased cloud cover and sediments in water. Extension, however, seemed to be under the direct influence of currents and sediments. The effect of environmen tal factors seemed more critical to calcification

Skeletal extension of staghorn coral Acropora formosa in relation to environment at Kavaratti atoll (Lakshadweep)

Growth study for 2 years, in rspect of skeletal extension, was conducted in situ at Kavaratti atoll. Average annual rate of extension of branches was 7.9 ± 2 cm for first year and 8.2 ± 1.8 em for second year. Growth of individual branches exhibited intracolony variations. Monthly rate of growth was found to be slower during monsoon (June-September) when compared to premonsoon (February-May) .and postmonsoon (October-January) seasons. Environmental conditions at the study area, with the exceptIOn of the amount of sediments in water, seemed conducive to the growth of Acropora formosa