Studies on Egg Production Index in Some Newly Evolved Multivoltine Breeds of the Silkworm, Bombyx mori L.

Gangopadhyay, Debnirmalya,Singh, Ravindra,Premalatha, V.,Rao, D.Raghavendra,Kariappa, B.K. Korean Society of Sericultural Science 2003 International Journal of Industrial Entomology Vol.7 No.2

To know the impact of female pupal weight corresponding to the male cocoon shell weight upon fecundity, hatchability and percentage of non-viable eggs, the experimental multivoltine breeds namely BL67 and 96A were categorised into low, medium and high batches according to the weight of female pupae and male cocoon shells and moths emerged from low, medium and high female pupae were allowed to mate withmoths emerged from low, medium and high male cocoon shells. Both the experimental breeds of BL67 and 96A revealed a fairl trend in fecundity for high batch > medium batch > low batch. When data were statistically analysed, a significant (p < 0.05) and a highly significant (p < 0.01) increase in fecundity was observed in the medium and high batches of BL67 during November - December, 2002 whereas highly significant (p < 0.01) increase was observed in the high batches of 96A during November - December, 2002. Data revealed a highly significant (p < 0.01) increase in fecundity in medium and high batches of both the breeds during January - February, 2003. More interestingly, a significant (p < 0.05) reduction was noted in percentage of non-viable eggs in high batches of 96A during January - February, 2003. But no significant variation in hatchability was noticed due to the effect of differential female pupal weight and male cocoon shell weight.

Front Surface Grid Design for High Efficiency Solar Cells

Gangopadhyay Utpal,Kim, Kyung-Hae,Basu Prabir Kanti,Dhungel Suresh Kumar,Jung, Sung-Wook,Yia, Jun-Sin The Korean Institute of Electrical and Electronic 2005 Transactions on Electrical and Electronic Material Vol.6 No.2

Standard crystalline solar cells are generally fabricated with the front grid pattern of silver paste contact. We have reported a detailed theoretical analysis of the proposed segmented cross grid line pattern in this paper. This work was carried out for the optimization of spacing and width of grid finger, main busbar and sub-busbar. The overall electrical and optical losses due to front contact were brought down to $10\%$ or even less as compared to the usual loss of $15\%$ or more in the conventional screen printed silver paste technology by choosing proper grid pattern and optimizing the grid parameters. The total normalized power loss for segmented mesh grid with plated metal contact was also observed and the total power loss could be brought down to $10.04\%$ unlike $11.57\%$ in the case of continuous grid and plated contact. This paper is able to outline the limitations of conventional screen printed contact.

Novel low cost chemical texturing for very large area industrial multi-crystalline silicon solar cells

Gangopadhyay, U,Dhungel, S K,Kim, K,Manna, U,Basu, P K,Kim, H J,Karunagaran, B,Lee, K S,Yoo, J S,Yi, J Institute of Physics 2005 Semiconductor science and technology Vol.20 No.9

<P>Multi-crystalline silicon surface etching without grain-boundary delineation is a challenging task for the fabrication of high efficiency solar cells. The use of sodium hydroxide–sodium hypochlorite (NaOH–NaOCl) solution for texturing a multi-crystalline silicon wafer surface in a solar cell fabrication line is reported in this paper. The optimized etching solution of NaOH–NaOCl does not have any effect on multi-crystalline silicon grain boundaries and it also has excellent isotropic etch characteristics, which ultimately helps to achieve higher values of performance parameters, especially the open circuit voltage (<I>V</I><SUB>oc</SUB>) and fill factor (FF), than those in the case of conventional silicon texturing. Easy control over the reaction of the NaOH–NaOCl solution is also one of the major advantages due to which sophistication in controlling the temperature of the etching bath is not required for the industrial batch process. The FTIR analysis of the silicon surface after etching with the current approach shows the formation of Si–Cl bonds, which improves the quality of the diffused junction due to chlorine gettering during diffusion. We are the first to report 14–14.5% efficiency of very large area (150 mm ? 150 mm) multi-crystalline silicon solar cells using a NaOH–NaOCl texturing approach in an industrial production line with a yield greater than 95%.</P>

Parthenogenesis in Silkworm, Bombyx mori L.

Gangopadhyay Debnirmalya,Singh Ravindra,Kariappa B. K.,Dandin S. B. Korean Society of Sericultural Science 2005 International Journal of Industrial Entomology Vol.10 No.1

Parthenogenesis in mulberry silkworm, Bombyx mori L. acquires immense use in the development of outstanding homozygous lines with higher viability, hybrid vigour, combining ability and less phenotypic variability. It can serve as a powerful tool in controlling sex of the offsprings as well as a useful tool in selection. In fact India is the second largest silk producing country in the world next only to China and all the five types of natural silks viz., mulberry, oak tasar, tropical tasar, muga and eri are produced in India. However, little information is available on the role of artificial parthenogenesis in the development of superior silkworm breeds. This paper overviews some important studies carried out on artificial parthenogenesis, and outline of different types of parthenogenesis, methods of induction of artificial parthenogenesis, factors responsible for successful parthenogenetic development, cytogenetics of artificial parthenogenesis and role of artificial parthenogenesis in silkworm breeding. Besides, an attempt is made to describe briefly about parthenogenetic engineering which includes cloning in silkworm, artificial insemination, chimeras, hybridization, chromosomal substitution and recombinant DNA in silkworm.

An Improved Method of Parthenogenetic Development and Analysis of Combining Ability in Bivoltine Breeds of the Silkworm, Bombyx mori L.

Gangopadhyay, D.,Singh, Ravindra Korean Society of Sericultural Science 2006 International Journal of Industrial Entomology Vol.13 No.2

Parthenogenesis, the development of unfertilized ovum opens new perspectives in silkworm breeding in the development of homozygous breeds. In order to improve induction of artificial parthenogenesis in the excised unfertilized eggs of different breeds of the silkworm, Bombyx mori L., a new method was devised and the results were compared with the routine method. General and specific combining abilities and hybrid vigour of newly developed bivoltine breeds were analyzed utilizing bivoltine breeds viz., $CSR_2,\;CSR_4,\;CSR_{17}\;and\;NB_4D_2$ Estimation of GCA revealed superiority of the breeds, $DNB_1$ for eight characters followed by $DNB_4$ for five characters. Among the testers, $CSR_2$ was found good general combiner for seven characters followed by $CSR_{17}$ for four characters. A great deal of variations was observed among the hybrids studied. Five hybrids namely, $DNB_1{\times}CSR_2,\;DNB_4{\times}CSR_4,\;DNB_4{\times}NB_4D_2,\;DNB_6{\times}CSR_2\;and\;DNB_7{\times}CSR_2$ showed significant SCA effects for 5-6 characters. The hybrid, $DNB_4{\times}CSR_4$ showed its superiority by expressing significant hybrid vigour over BPV for 7 characters. Majority of the hybrids exhibited significant hybrid vigour for survival rate, yield/10,000 larvae by weight, cocoon weight, cocoon shell weight, filament length and denier.

Parthenogenesis in silkworm, Bombyx mori L.

Debnirmalya Gangopadhyay,Ravindra Singh,B. K. Kariappa,S. B. Dandin 한국잠사학회 2005 International Journal of Industrial Entomology Vol.10 No.1

Parthenogenesis in mulberry silkworm, Bombyx mori L. acquires immense use in the development of outstanding homozygous lines with higher viability, hybrid vigour, combining ability and less phenotypic variability. It can serve as a powerful tool in controlling sex of the offsprings as well as a useful tool in selection. In fact India is the second largest silk producing country in the world next only to China and all the five types of natural silks viz., mulberry, oak tasar,tropical tasar, muga and eri are produced in India.However, little information is available on the role of artificial parthenogenesis in the development of superior silkworm breeds. This paper overviews some important studies carried out on artificial parthenogenesis,and outline of different types of parthenogenesis, methods of induction of artificial parthenogenesis,factors responsible for successful parthenogenetic development, cytogenetics of artificial parthenogenesis and role of artificial parthenogenesis in silkworm breeding. Besides, an attempt is made to describe briefly about parthenogenetic engineering which includes cloning in silkworm, artificial insemination, chimeras, hybridization, chromosomal substitution and recombinant DNA in silkworm.

Design and Evaluation of Ergonomic Interventions for the Prevention of Musculoskeletal Disorders in India

Somnath Gangopadhyay,Samrat Dev 대한직업환경의학회 2014 대한직업환경의학회지 Vol.26 No.-

Background: Improper workstation, work procedures and tools are found to be the risk factors for the development of musculoskeletal disorders among the informal sector workers of the developing countries. Low cost ergonomic interventions can effectively improve such adverse conditions. Case presentation: In the present article some studies related to design interventions in different informal and agricultural sectors were discussed and their efficacies were analyzed. It was observed that with the help of appropriate interventions musculoskeletal disorders were reduced, adverse physiological conditions were improved when awkward postures were corrected and ultimately the organisational productivity was increased. Conclusion: Proper implementation of ergonomic interventions can ultimately improve the economy of the nation.

Biracial Silicon Solar Cells with Spin-on Doping and Electroless Plating

U. Gangopadhyay,Kim, Kyung-Hae,S.K. Dhungel,D. Mangalaraj,Park, J.H.,J. Yi The Korean Institute of Electrical and Electronic 2004 Transactions on Electrical and Electronic Material Vol.5 No.1

A new method for fabrication of transistor like structure of the bifacial solar cell using spin-on doping and electroless plating has been proposed and the basic characteristics of the bifacial cell have been investigated. It is found that 9% increase in short circuit current is achieved with bifacial connection than the unifacial connection. Some unwanted effect of the series resistance on collection efficiency under different mode of illumination has been pointed out. Loss mechanisms inherent in the transistor like bifacial structure have also been discussed.

An Improved Method of Parthenogenetic Development and Analysis of Combining Ability in Bivoltine Breeds of the Silkworm, Bombyx mori L.

( D. Gangopadhyay ),( Ravindra Singh ) 한국잠사학회 2006 International Journal of Industrial Entomology Vol.13 No.2

Parthenogenesis, the development of unfertilized ovum opens new perspectives in silkworm breeding in the development of homozygous breeds. In order to improve induction of artificial parthenogenesis in the excised unfertilized eggs of different breeds of the silkworm, Bombyx mori L., a new method was devised and the results were compared with the routine method. General and specific combining abilities and hybrid vigour of newly developed bivoltine breeds were analyzed utilizing bivoltine breeds viz., CSR2, CSR4, CSR17 and NB4D2. Estimation of GCA revealed superiority of the breeds, DNB1 for eight characters followed by DNB4 for five characters. Among the testers, CSR2 was found good general combiner for seven characters followed by CSR17 for four characters. A great deal of variations was observed among the hybrids studied. Five hybrids namely, DNB1 × CSR2, DNB4 × CSR4, DNB4 × NB4D2, DNB6 × CSR2 and DNB7 × CSR2 showed significant SCA effects for 5-6 characters. The hybrid, DNB4 × CSR4 showed its superiority by expressing significant hybrid vigour over BPV for 7 characters. Majority of the hybrids exhibited significant hybrid vigour for survival rate, yield/10,000 larvae by weight, cocoon weight, cocoon shell weight, filament length and denier.

Porous Silicon as Pressure Sensing Material

U. Gangopadhyay,이준신,C. Pramanik,H. Saha,김경해 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.3

In this paper, the pressure-sensing property of porous silicon is reported. The motivation behind this study is to modify silicon to make it more sensitive in the low-pressure range. The sensitivity of a porous silicon membrane towards pressure has been studied and observed to be three times greater than that of mono-crystalline silicon, since there is the possibility of improvement in piezoresistance due to quantum confinement in the porous silicon nanostructure. The piezoresistive coefficient of porous silicon has also been estimated from experimental observations and stress calculations.