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

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

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

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

Awareness of farmers about social forestry programme - an analysis

A study was conducted to assess the awareness level of farmers on various components of Social forestry Programme, implemented by the Social Forestry Department in Ke rala State, India. It could be inferred/rom the study that the awareness level on /arm/oreslry lVas very high. On the other hand the awareness level on coastal area plantations and fodder plantations was relatively lesser. Variables such as education, material possession, media participation, contact with extension agency and economic motivation had a positive relationship with the awarelIess level of marginal farmers whereas variables like age, occupation, social participation and risk orientation had a negative influence on awareness. It was also observed that exceptfor education and risk orientation, all the other variables had a positive relationship with the awareness level of small farmers

Effect of TEA on the structural and magnetic properties of ferromagnetic ZnFe2O4 nanoparticles

Ferromagnetic ZnFe2O4 nanoparticles were synthesized by surfactant assisted hydrothermal method using different amount of triethylamine (TEA). The synthesized nanoparticles were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution transmission electron microscopy and vibrating sample magnetometer. The formation of single phase ZnFe2O4 was investigated by addition of different amount of TEA. Regular spinel structure was obtained for all synthesized product except for lower amount of TEA, owing to the less alkaline atmosphere. All the synthesized nanoparticles were spherical in shape with a small aggregation. Observed size of the nanoparticles was 10 nm as determined from TEM measurement for the sample synthesized with a higher amount of TEA. Room temperature ferromagnetic behavior was observed in all the samples

Performance studies on millet processing machinery for tribal livelihood promotion

A Millet Processing Centre for processing of minor millets in a tribal village in Tamil Nadu, has been established with the following millet processing machinery viz., Destoner, Millet Mill, Grain Polisher, Pulveriser, Flour Sifter and Packaging Machinery for enhancement of tribal livelihood. Performance studies on the machinery for processing minor millets viz., little millet, foxtail millet and finger millet grown in the tribal area were carried out. Based on the performance evaluation, the output capacity of destoner cum cleaner was found to be 230 kg/h and 233 kg/h for little and foxtail millet respectively with a cleaning efficiency of 89 and 90% respectively for the above millets. The performance of millet mill revealed that the output capacity was 90-92 kg/h for little and foxtail millet with a dehulling efficiency of 86 and 87% respectively with small percentage of brokens (< 5 %). The capacity of grain polisher was 60-61 kg/h with a polishing efficiency of 85% & 86% respectively for little and foxtail millet. The pulveriser was evaluated for finger millet flour making whereby the output capacity of the machine was 75 kg/h with a milling efficiency of 90% respectively. The cost economics revealed that the tribal farmers could save 85% of the processing cost. The benefit cost ratio was found to be 2.05.The total profit to the tribal Society through Millet Processing Centre was Rs. 21,000/- during the first harvesting season of millets. The above studies have paved way for satisfactory functioning of the Millet Processing Centre in the tribal area

Differential narrow focusing of immunodominant human immunodeficiency virus Gag-specific cytotoxic T-Lymphocyte responses in infected African and Caucasoid adults and children

Cytotoxic T-lymphocyte (CTL) activity plays a central role in control of viral replication and in determining outcome in cases of human immunodeficiency virus type 1 (HIV-1) infection. Incorporation of important CTL epitope sequences into candidate vaccines is, therefore, vital. Most CTL studies have focused upon small numbers of adult Caucasoid subjects infected with clade-B virus, whereas the global epidemic is most severe in sub-Saharan African populations and predominantly involves clade-C infection in both adults and children. In this study, sensitive enzyme-linked immunospot (elispot) assays have been utilized to identify the dominant Gag-specific CTL epitopes targeted by adults and children infected with clade-B or -C virus. Cohorts evaluated included 44 B-clade-infected Caucasoid American and African American adults and children and 37 C-clade-infected African adults and children from Durban, South Africa. The results show that 3 out of 46 peptides spanning p17Gag and p24Gag sequences tested contain two-thirds of the dominant Gag-specific epitopes, irrespective of the clade, ethnicity, or age group studied. However, there were distinctive differences between the dominant responses made by Caucasoids and Africans. Dominant responses in Caucasoids were more often within p17Gag peptide residues 16 to 30 (38 versus 12%; P 30% of the total infected population in Durban. This epitope is closely homologous with dominant HIV-2 and simian immunodeficiency virus Gag-specific CTL epitopes. The fine focusing of dominant CTL responses to these few regions of high immunogenicity is of significance to vaccine design

The clustering instability of inertial particles spatial distribution in turbulent flows

A theory of clustering of inertial particles advected by a turbulent velocity field caused by an instability of their spatial distribution is suggested. The reason for the clustering instability is a combined effect of the particles inertia and a finite correlation time of the velocity field. The crucial parameter for the clustering instability is a size of the particles. The critical size is estimated for a strong clustering (with a finite fraction of particles in clusters) associated with the growth of the mean absolute value of the particles number density and for a weak clustering associated with the growth of the second and higher moments. A new concept of compressibility of the turbulent diffusion tensor caused by a finite correlation time of an incompressible velocity field is introduced. In this model of the velocity field, the field of Lagrangian trajectories is not divergence-free. A mechanism of saturation of the clustering instability associated with the particles collisions in the clusters is suggested. Applications of the analyzed effects to the dynamics of droplets in the turbulent atmosphere are discussed. An estimated nonlinear level of the saturation of the droplets number density in clouds exceeds by the orders of magnitude their mean number density. The critical size of cloud droplets required for clusters formation is more than $20 \mu$m.Comment: REVTeX 4, 15 pages, 2 figures(included), PRE submitte