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Aggarwal N.,University of Delhi | Joshi B.,Technology Bhavan | Bhattacherjee A.B.,Jawaharlal Nehru University
Journal of Physics: Conference Series | Year: 2016

We investigate the effect of optomechanical coupling on the squeezed-spin states for a Bose-Einstein Condensate embedded within the lossless optomechanical cavity for the three special cases of initial states of cavity field, namely, a coherent state, a squeezed vacuum state and a squeezed state. We show that the radiation pressure or pondermotive force acting on the cavity end mirror plays a significant role in producing the atomic-squeezed states by producing squeezed states of the cavity field which is then transferred to the condensate. We further show that the maximum spin-squeezing along the x-direction is obtained in the presence of optomechanical coupling for the initial cavity field prepared in the amplitude squeezed state, whereas, squeezing along the y-direction reaches a maximum value in the absence of optomechanical coupling for the initial coherent cavity field. We also study the additional effect of nonlinear atomic interaction on spin-squeezing. © Published under licence by IOP Publishing Ltd. Source


Shukla S.K.,University of Delhi | Bharadvaja A.,University of Delhi | Parashar G.K.,University of Delhi | Mishra A.P.,Technology Bhavan | And 2 more authors.
Advanced Materials Letters | Year: 2012

Thin films of titanium dioxide in anatase form have been prepared using isobutyl titanate as precursor. The resulting TiO2 was coated on an U-shaped pyrex glass rod to sense the humidity of a controlled humid environment using optical fiber approach. The humidity sensing characteristics and the sensing mechanism have been investigated by measuring the output power of the sensor at different humidity. The developed humidity sensor was responded in the humidity ranging from 10 to 95% of relative humidity and exhibited the sensitivity of 0.78, response time 36s and recovery time 73s. © 2012 VBRI Press. Source


Bejoy M.,Jawaharlal Nehru Tropical Botanic Garden and Research Institute | Amsh N.P.,Technology Bhavan | Radhika B.J.,Jawaharlal Nehru Tropical Botanic Garden and Research Institute | Nair G.M.,Central University of Kerala
Biotechnology | Year: 2012

Ochlandra wightii (Munro) Fisch., an endemic reed bamboo in the Southern Western Ghats has been multiplied using tissue culture techniques. In vitro production of O. wightii plantlets has been achieved by using isolated embryos from mature seeds and nodal segments from in vitro seedlings. Better germination of isolated embryos (85%) was noticed in BAP (6-benzyl amino purine) (0.5 mg L-1) with 1-2 shoots in 30 days. Half-strength MS medium supplemented with BAP (0.5 mg L-1) andTDZ (Thidiazuron) (0.5 mg L-1) enhanced the rate of shoot multiplication to an average of 9.8 shoots in 60 days. Simultaneous development of roots along with shoots was also noticed. Rhizome induction was achieved from 65% of seedling cultures when treated with KN (Kinetin) (1 mg L-1) and higher concentration of sucrose (4%) in 35 days. Multiple shoots were also induced from nodal explants obtained from in vitro seedlings. Average 3.6 shoots were achieved in 40 days when treated with BAP (2 mg L-1) andKN (0.5 mg L-1). Twenty percent of the nodal cultures developed 1-2 roots during shoot development and the rest were rooted in half-strength MS solid medium supplemented with IBA (indole-3-butyric acid) (0.5 mg L-1). Plantlets with healthy roots were hardened and transplanted to the clay pots. They showed 80% survival after 6 months. However, the plantlets with in vitro rhizomes showed 100% survival. Development of new culms and rhizomes were noticed after 3 months of greenhouse growth. Around 880 plantlets could be generated in 9 months from 10 embryos isolated from mature seeds using this protocol. © 2012 Asian Network for Scientific Information. Source


Bejoy M.,Lawaharlal Nehru Tropical Botanic Garden and Research Institute | Dan M.,Lawaharlal Nehru Tropical Botanic Garden and Research Institute | Anish N.P.,Technology Bhavan | Nair A.R.G.,Lawaharlal Nehru Tropical Botanic Garden and Research Institute | And 2 more authors.
Biotechnology | Year: 2012

Curcuma vamana Sabu and Mangaly, a wild relative of tunneric, is endemic to Kerala and its germplasm deserves special conservation measures. A micropropagation protocol has been outlined for the production of complete plantlets within 85 days. Nodal segments isolated from stoloniferous rhizomes achieved 60% bud break within 20 days. These explants responded in BAP ( .0mg L ')supplemented medium with the sprouting of 1-3 shoots in 6-7 weeks of incubation. In vitro shoots obtained from primary cultures were used for further studies to minimise collection from the small wild populations of C. vamana. Efficient shoot multiplication has been obtained from in vitro shoot explants using thidiazuron (TDZ). The highest rate of shoot production was found in 0.5 mg L TDZ which produced 9.6 shoots. Rhizogenesis was observed along with collagenesis in all treatments. Effect of various nutrient formulations was also compared The best shoot multiplication response has been observed in Murashige and Skoog (MS) medium followed by Nitsch, Woody Plant (WPM), C (B5) and White's formulations. MS medium recorded about five-fold increase in the rate of shoot multiplication compared to that of the least responding medium under identical culture conditions. The regenerated plantlets were successfully established in the greenhouse condition with 90% survival. © 2012 Asian Network for Scientific Information. Source


Banerjee P.,CSIR - Central Electrochemical Research Institute | Singh V.S.,CSIR - Central Electrochemical Research Institute | Chatttopadhyay K.,Satyam Computer Services Ltd. | Chandra P.C.,Central Ground Water Board | Singh B.,Technology Bhavan
Journal of Hydrology | Year: 2011

The paper evaluates the prospect of artificial neural network (ANN) simulation over mathematical modeling in estimating safe pumping rate to maintain groundwater salinity in island aquifers. Feed-forward ANN model with quick propagation (QP) as training algorithm has been used to forecast the salinity under varied pumping rates. The accuracy, generalization ability and reliability of the model are verified by real-time field data. The model is trained with 2 years of real-time field data and prediction on water quality with varying pumping rate is made for a span of 5 years. The same is then compared with both real-time field data and the prediction based on SUTRA (Saturated-Unsaturated Transport) computations. The proposed ANN model has surfaced as a simpler and more accurate alternative to the numerical method techniques. The ANN methodology using minimal lag and number of hidden nodes, along with the optimal number of spatial and temporal variables consistently produced the best performing network based simulation models. The prediction accuracy of the ANN model has been extended for another 5 years to further define the limit of pumping at a permissible level of groundwater salinity. © 2010 Elsevier B.V. Source

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