In the present work we have prepared and characterized the two ternary forms of cobalt titanate namely ilmenite and cubic by the sol-gel technique simply by replacing the titanium precursor and using a cationic surfactant micelle solution followed by calcinations at 600°C and 800°C respectively. In both cases, the nanopowders revealed a dark bluish green color, different morphologies of spherical, rhombus and needle shapes with mean particle sizes 29 and 37 nm, respectively. Bearing growing environmental concerns in mind, we have also highlighted a simple nano chemistry based clean and efficient process for effective degradation of hazardous malachite green oxalate dye by an in-situ ultraviolet irradiation set-up. In this field there is hardly any report involving comparative study of ternary oxides of cobalt as potential candidates for photo catalytic degradation. We ultimately observed that cobalt meta titanate proved itself the optimal catalyst at a calcination temperature of 600°C showing a maximum degradation efficiency of 96.38% It also showed a better first-order rate constant of 0.01636 min -1 . A decent attempt to correlate photoluminescence and photo catalysis has also been made. Also, a heterojunction has been fabricated with cobalt meta titanate and the parameters of crucial importance in photocatalysis namely conductivity, carrier mobility, transit time evaluated from the current-voltage characteristics.
Keywords: Nanoparticles; CTAB micelle solution; Photocatalytic degradation; Reaction kinetics, Heterojunction

Recently, dye sensitized photovoltaic cell plays an important role as a renewable source of energy because of low material cost, easy processing techniques. But the organic devices are prone to traps due to which charge carriers get trapped or recombined within the device before collection at the electrodes. So traps limit the device performance. The study on the charge transport mechanism enables us to estimate this trap energy. In this work, we have designed the photovoltaic device and estimated the trap energy of inexpensive water-soluble Fuchsin dye based photovoltaic cells. To design a photovoltaic device we have used ITO as a front electrode and copper as a back electrode. 540mg of TiO 2 nanoparticles and 100mg of Fuchsin dye mixed well in N, N-Dimethyl formamide (DMF). A thin layer of this TiO 2 nanoparticles and dye has been deposited between two electrode using popular method named doctor’s blade method. A drop of electrolyte made of lithium percolate (LiClO 4 ), ethylene carbonate (EC) and propylene carbonate (PC) solution has been used to obtain better device performance. The analysis of dark current density- voltage (J-V) characteristics using exponential charge transport mechanism of this photovoltaic cell the trap energy has been calculated 0.5399 ± 0.006 eV. Also, we have observed photovoltaic effect of this device. Under illumination of 120 kLUX intensity, maximum short circuited current density is obtained 4.62 μA/cm 2 and open circuited voltage is 0.24 Volt.
Keywords: Fuchsin dye, trap energy, short-circuited current density, open-circuited voltage.

In this work we study the effect of temperature and pressure on the dynamics of calmodulin protein using molecular dynamics simulations. The calmodulin protein is used for this study as a first step which can be extended further to other proteins. Calmodulin is a calcium binding protein and thus plays a very important role in the transport of calcium ions inside the cell. The temperature is earlier reported to play an important role in the dynamics of this protein which is applicable to the other proteins as well. In this study we therefore study the combined effect of temperature and pressure on the conformation change of this protein. The pressure alone is not observed to play a significant role in the dynamics of the protein whereas pressure along with temperature is observed to change the conformation of the protein to a large extent. The results were confirmed with the molecular dynamics simulations performed with the help of NAMD software. These results are consistent with the experimental results of the other workers performed with fourier transform infrared spectroscopy. Temperature is observed to pave pathways to expand/unfold the whole protein structure making it more susceptible to the effects of pressure.
Keywords: Protein, Conformation, Calmodulin, Molecular Dynamics

An idea towards the low threshold optical bistability and tunability of bistable thresholds at THz frequency under realistic situation is analyzed through a proposed multilayered configuration. The proposed configuration comprises a coupling prism of silicon, and monolayer graphene sheets spatially separated through 35 nm thick polymer which is sandwiched between an air gap of thickness 4.6 μm and a kerr polymer (GaAs) at 300 K temperature and at an incident light frequency of 2 THz. Utilizing the large nonlinear effect of the configuration obtained by the nonlinearity of the kerr polymer and the high local field effect due to long-range graphene surface plasmon resonance, the switching-down and switching-up threshold values for optical bistability have been markedly reduced upto 1.21×10 5 V/m and 1.24×10 5 V/m respectively thereby rendering a minimum threshold intensity of 7.2 kW/cm 2 than the articles reported till date. Tunability of the switching-down and switching-up threshold values have also been realized from 1.21×10 5 V/m to 5.18×10 5 V/m and 1.24×10 5 V/m to 1.424×10 6 V/m respectively through electrical or chemical modification of the charge carrier density and hence fermi energy of the graphene from 0.23 eV to 0.41 eV and from 1.21×10 5 V/m to 1.56×10 5 V/m and 1.24×10 5 V/m to 2.12×10 5 V/m respectively for the variation in incident angle from 70° to 88°. The effect of damping rate of graphene on optical bistability behavior has also been observed. Therefore the proposed optical bistable configuration finds potential applications in the field of all-optical switching, optical transistor, optical logic, nano-illumination and optical memory with low input threshold at THz frequency and can also be used to realize tunable optical bistable device for future THz optical communication technology.
Keywords: Optical Bistability, Plasmonics, Graphene Plasmons, Electromagnetic optics