The motion of bubbles inside drops in containerless processing

A theoretical model of thermocapillary bubble motion inside a drop, located in a space laboratory, due to an arbitrary axisymmetric temperature distribution on the drop surface was constructed. Typical results for the stream function and temperature fields as well as the migration velocity of the bubble were obtained in the quasistatic limit. The motion of bubbles in a rotating body of liquid was studied experimentally, and an approximate theoretical model was developed. Comparison of the experimental observations of the bubble trajectories and centering times with theoretical predictions lends qualified support to the theory

Involvement of extension personnel in implementing social forestry programmes

In a country like India, where the population is high and resources are limited, social forestry is an instrument for rural development, particularly for the poor people. Thus social forestry is identified as a forestry of the people, by the people and for the people

Enterocin from Enterococcus faecium isolated from mangrove environment

Enterococcus faecium isolated from mangrove environment produced enterocin and it showed broad inhibitory spectrum against gram positive and gram negative bacteria such as Lactobacillus plantarum, Enterococcus facealis, Listeria monocytogens and Salmonella paratyphii. The optimum production ofbacteriocin (2400 AU/ml) from E. faceium was obtained when the culture conditions were maintained at pH 6.0 and 35°C. Maximum yield was 40% in ion exchange chromatography. The molecular weight of the partially purified enterocin was estimated as 5 KDa by SDS PAGE electrophoresis

Studies on the proteinaceous gel secretion from the skin of the catfish, Arius maculatus (Thunberg, 1792)

The Catfish Arius maculatus (Thunberg, 1792) causes injury to the fisherman while handling the fish and it was proven that the skin mucus of the fish have several properties including the toxicity. In the present study, the biochemical property of the catfish skin mucus was characterized and it was found that the protein content of the soluble and insoluble fractions were 9.34 and 12.64 ìg/g, respectively. The total lipid was 0.005 ìg/g and the total carbohydrate was 0.08 ìg/g. Of the total 17 amino acids recorded, cysteine availability was very low; 0.01 and 0.02 mole % in the soluble and insoluble fractions, respectively. Leucine was available in high quantity (9.8 mole %) in the soluble fraction and aspartic acid (9.0 mole %) was high in the insoluble fraction. On SDS-PAGE analysis, seven and six bands with a distinct band at 35 KDa in the soluble and insoluble fractions, respectively, were observed. On haemolytic activity, lysis was observed by 50 ìg/ml of insoluble fraction and 25 ìg/ml of soluble fraction. Both soluble and insoluble fractions showed maximum and minimum activities against Escherichia coli and Pseudomonas aueruginosa, respectively

Physical phenomena in containerless glass processing

Experiments were conducted on bubble migration in rotating liquid bodies contained in a sphere. Experiments were initiated on the migration of a drop in a slightly less dense continuous phase contained in a rotating sphere. A refined apparatus for the study of thermocapillar flow in a glass melt was built, and data were acquired on surface velocities in the melt. Similar data also were obtained from an ambient temperature fluid model. The data were analyzed and correlated with the aid of theory. Data were obtained on flow velocities in a pendant drop heated from above. The motion in this system was driven principally by thermocapillarity. An apparatus was designed for the study of volatilization from a glass melt

Nanoscale quantum dot infrared sensors with photonic crystal cavity

We report high performance infrared sensors that are based on intersubband transitions in nanoscale self-assembled quantum dots combined with a microcavity resonator made with a high-index-contrast two-dimensional photonic crystal. The addition of the photonic crystal cavity increases the photocurrent, conversion efficiency, and the signal to noise ratio (represented by the specific detectivity D*) by more than an order of magnitude. The conversion efficiency of the detector at Vb=–2.6 V increased from 7.5% for the control sample to 95% in the PhC detector. In principle, these photonic crystal resonators are technology agnostic and can be directly integrated into the manufacturing of present day infrared sensors using existing lithographic tools in the fabrication facility