Lattice Induced Transparency in Metasurfaces

Lattice modes are intrinsic to the periodic structures and their occurrence can be easily tuned and controlled by changing the lattice constant of the structural array. Previous studies have revealed excitation of sharp absorption resonances due to lattice mode coupling with the plasmonic resonances. Here, we report the first experimental observation of a lattice induced transparency (LIT) by coupling the first order lattice mode (FOLM) to the structural resonance of a metamaterial resonator at terahertz frequencies. The observed sharp transparency is a result of the destructive interference between the bright mode and the FOLM mediated dark mode. As the FOLM is swept across the metamaterial resonance, the transparency band undergoes large change in its bandwidth and resonance position. Besides controlling the transparency behaviour, LIT also shows a huge enhancement in the Q-factor and record high group delay of 28 ps, which could be pivotal in ultrasensitive sensing and slow light device applications.Comment: 5 figure

Histopathological Changes in Kidneys of Developing Chick Embryo on Exposure to Lixisenatide

Chick embryo is one of the most commonly used animals to study the adverse effects of various drugs for research purpose. Currently, type 2 diabetes mellitus is treated using the medication lixisenatide. Therapeutically, is thought to be superior to other GLP1 receptor antagonists for the treatment of type 2 diabetes. To understand the adverse effects of lixisenatide on kidney of developing chick embryo

Thermoelectric properties of InSe and AlSe bilayer thin films

The indium selenide (InSe) and aluminum selenide (AlSe) bilayer thin films of different thickness ratio have been prepared using thermal evaporation at vacuum. Thermoelectric behaviour of each sample has been determined temperature regions of 300-310 K. The thermoelectric behaviour of prepared thin films has been found to improve when samples have been annealed in vacuum at 70 ºC and 100 ºC. Electrical studies have been carried out of each film before and after annealing

All-optical active THz metasurfaces for ultrafast polarization switching and dynamic beam splitting.

Miniaturized ultrafast switchable optical components with an extremely compact size and a high-speed response will be the core of next-generation all-optical devices instead of traditional integrated circuits, which are approaching the bottleneck of Moore's Law. Metasurfaces have emerged as fascinating subwavelength flat optical components and devices for light focusing and holography applications. However, these devices exhibit a severe limitation due to their natural passive response. Here we introduce an active hybrid metasurface integrated with patterned semiconductor inclusions for all-optical active control of terahertz waves. Ultrafast modulation of polarization states and the beam splitting ratio are experimentally demonstrated on a time scale of 667 ps. This scheme of hybrid metasurfaces could also be extended to the design of various free-space all-optical active devices, such as varifocal planar lenses, switchable vector beam generators, and components for holography in ultrafast imaging, display, and high-fidelity terahertz wireless communication systems

All-optical active THz metasurfaces for ultrafast polarization switching and dynamic beam splitting.

Miniaturized ultrafast switchable optical components with an extremely compact size and a high-speed response will be the core of next-generation all-optical devices instead of traditional integrated circuits, which are approaching the bottleneck of Moore's Law. Metasurfaces have emerged as fascinating subwavelength flat optical components and devices for light focusing and holography applications. However, these devices exhibit a severe limitation due to their natural passive response. Here we introduce an active hybrid metasurface integrated with patterned semiconductor inclusions for all-optical active control of terahertz waves. Ultrafast modulation of polarization states and the beam splitting ratio are experimentally demonstrated on a time scale of 667 ps. This scheme of hybrid metasurfaces could also be extended to the design of various free-space all-optical active devices, such as varifocal planar lenses, switchable vector beam generators, and components for holography in ultrafast imaging, display, and high-fidelity terahertz wireless communication systems

Productivity, profitability and resource use efficiency of potato (Solanum tuberosum) based cropping systems in eastern Himalayan region

A field experiment was conducted during three consecutive years of 2011 to 2013 at Central Potato Research Station, Shillong to evaluate the economic feasibility of potato (Solanum tuberosum L.) based cropping system under rainfed condition of eastern Himalayan region. There were seven cropping systems replicated thrice under randomized block design. The potato was the main crop during summer season while succeeding seven crops (potato, maize, cabbage, cauliflower, carrot, rajmash and radish) were taken during autumn season. Results revealed that potato based various cropping sequence differ significantly for most of the desirable parameters which decided the economic viability to adopt the system approach for efficient utilization of natural resources. Among the cropping systems, potato-cabbage recorded significantly the highest potato tuber equivalent yield (51.6 tonnes/ha), production efficiency (210.5 kg/ha/day), economic efficiency (Rupees 1414.6 /ha/day), maximum net monetary return (Rupees 366.8 x 103/ha), benefit cost ratio (3.5) and energy productivity (1.35 kg/MJ). Hence, potato-cabbage was concluded as the most stable and profitable cropping system for the ecosystem of eastern Himalayan region

Estimation of Pesticide Residues in Fruits, Vegetables and Water

Nowadays, pesticide use is on increase day by day in every field of life like agriculture, household and in industry. Most of the pesticides are not biodegradable and those which are degradable cannot degrade completely. Hence, they reach to our fruits, vegetables, grains and water bodies. Even after washing the pesticide residues left in our foodstuffs. Since last decade, it has been observed that analysed pesticide residues were either BDL or < MRL in the majority of samples. In this study vegetable, fruits and grains are an important food item and proper care should be taken to use the very safe pesticide fort avoiding potential risks to human. It is, therefore, suggested that the food item collected from in and around Lucknow City, India is comparatively safe from pesticide residues. A periodical monitoring of pesticide residues in other food commodities is the recent need for the consumers as well as authorities of food quality control