Giant Goos-H\"anchen shift in Scattering: the role of interfering Localized Plasmon modes

The longitudinal and the transverse beam shifts, namely, the Goos-H\"anchen (GH) and the Spin-Hall (SH) shifts are usually observed at planar interfaces. It has recently been shown that the transverse SH shift may also arise due to scattering of plane waves. Here, we show that analogous in-plane (longitudinal) shift also exist in scattering of plane waves from micro/nano systems. We study both the GH and the SH shifts in plasmonic metal nanoparticles/ nanostructures and dielectric micro-particles employing a unified framework that utilizes the transverse components of the Poynting vector of the scattered wave. The results demonstrate that interference of neighboring resonance modes in plasmonic nanostructures (e.g., electric dipolar and quadrupolar modes in metal spheres) leads to giant enhancement of GH shift in scattering from such systems. We also unravel interesting correlations between these shifts with the polarimetry parameters, diattenuation and retardance.Comment: 4 pages, 3 figure

Gamma Radiolytic Degradation of 4-Chlorophenol Determination of Degraded Products with HPLC and GC-MS

Contamination by chlorophenols of surface water and groundwater is an emerging issue in environmental science and engineering. After their usage as pesticide, herbicide and disinfectant, these organic compounds subsequently enter the aquatic environment through a number of routes. Some of the chlorophenols are slightly biodegradable, while others are more persistent and mobile in the aquatic environment especially chlorophenols. Gamma radiolytic degradation is one of advance oxidation process that has been thought to be one of the promising treatments to deal with this problem. This radiolytic study was carried out in methanolic 4-CP (4-chlorophenol) samples. Among several factors effecting radiolytic degradation of 4-CP, dose and concentration are important that were evaluated under atmospheric conditions. A degradation yield (G –value) for 4-CP of 0.38 and 1.35 was achieved in 20 and 100mg/dm3 solution. It was observed that degradation yield decreases with increasing 4-CP concentration. Gamma radiolysis produce free radicals in solvent which further react with 4-CP molecules to generate different products. The identification of degradation products was proposed using HPLC and GC-MS

Effects of foliar application of melatonin on gas exchange and certain biochemical characteristics broccoli cv. Palam Samridhi

Considering the rich nutritional status and possibility of broccoli in improving the profitable yield, and wide role of Mel in regulating the plant physiological process, an investigation was carried out at the division of Basic Sciences and Humanities during 2017 to investigate the effect of foliar application of Mel on leaf photosynthetic and biochemical attributes broccoli. Thirty days old and uniform seedlings of broccoli cv. Palam Samridhi were transplanted in the field at a spacing of 45 × 45cm. Different concentrations of Mel, viz. 0, 20, 40, 60 and 80 ppm were sprayed on the plant foliage at 15 days after transplanting (DAT) replicating each treatment four times. Leaf gas exchange and biochemical attributes were tested following the standard procedures. The Results showed the lowest stipulated rate of photosynthesis (10.87 µmole.m-2.sec-1), stomatal conductance (301.44 mole H2O.m-2ses-1) and leaf transpiration (1. 14 mole H2O.m-2ses-1) in untreated plants.  Different doses of Mel significantly increased the values of these attributes and the highest values of photosynthesis (18.63 µmole.m-2.sec-1), stomatal conductance (324.37 mmole.m-2.ses-1) and leaf transpiration (3.23 mmole.m-2.ses-1) with Mel 60 ppm were recorded. The alterations in different biochemical attributes were also evident due to foliar application of Mel and maximum leaf sugar (77.0 and 85.9µg/g), protein (56.9 and 77.3 µg/g), total phenols (260.1 and 339.9 mg/100g), antioxidants (142.8 and 159.9 mg GAE /100g DW) and MSI (94.89 and 97.43 percent) values with Mel 60ppm at 30 and 60DAT, respectively. Therefore, the present study signifies the useful effects of Mel in regulating the physio-biochemical properties of broccoli

Designer Multimode Localized Random Lasing in Amorphous Lattices at Terahertz Frequencies

Random lasers are a special class of laser in which light is confined through multiple scattering and interference process in a disordered medium, without a traditional optical cavity. They have been widely studied to investigate fundamental phenomena such as Anderson localization, and for applications such as speckle-free imaging, benefitting from multiple lasing modes. However, achieving controlled localized multi-mode random lasing at long wavelengths, such as in the terahertz (THz) frequency regime, remains a challenge. Here, we study devices consisting of randomly-distributed pillars fabricated from a quantum cascade gain medium, and show that such structures can achieve transversemagnetic polarized (TM) multi-mode random lasing, with strongly localized modes at THz frequencies. The weak short-range order induced by the pillar distribution is sufficient to ensure high quality-factor modes that have a large overlap with the active material. Furthermore, the emission spectrum can be easily tuned by tailoring the scatterer size and filling fraction. These “designer” random lasers, realized using standard photolithography 2 techniques, provide a promising platform for investigating disordered photonics with predesigned randomness in the THz frequency range, and may have potential applications such as speckle-free imaging

Enhancing crop resilience through thiamine: implications for sustainable agriculture in drought-stressed radish

During 21st century, abiotic stress has adversely affected the agriculture crop production around the globe. Keeping in view the food requirement under water shortage condition, a study was planned to investigate the effect of thiamine application on radish crop under drought stress conditions on plant. For study purpose, two varieties of locally available radish (‘Early-Milo’ and ‘Laal-Pari’) were grown with normal water application as well as thiamine (100 mg L-1) application while maintaining a stress condition (60% field capacity). Increasing water deficit stress linearly reduced plant growth, yield and biomass in both varieties by reducing water use efficiency, while significantly enhanced these attributes with thiamine application. Thiamine application under drought stress exerted significant impacts on physiological attributes in both varieties, including enhanced osmolytic attribute in drought conditions and improvements in superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), H2O2, and malondialdehyde (MDA) activities in plant leaves. Antioxidant and osmoprotectant upregulation positively linked to radish crop's drought tolerance. Moreover, PCA and heatmap analysis revealed a significant interdependence among various traits and interconnected in determining the crop's capacity to sustain growth under conditions of drought stress. In crux, thiamine application conclusively enhances radish growth, yield, biomass, physio-chemical and osmolytic attributes, ionic composition and enzymatic antioxidant potential. Therefore, it is recommended to consider the application of thiamine in commercial agriculture practices to mitigate the negative effects of drought stress on radish crop production

Comparison of automatically generated reaction mechanism for oxidation of simple hydrocarbons in IC engine

In this work, a detailed kinetic reaction mechanism, consisting of 208 reactions and 79 species, has been developed todescribe the oxidation of simple hydrocarbon fuel (natural gas) in IC engine. The performance of the proposed mechanismis tested using simulation, tool CHEMKIN 4.1.1, and experimental measurements. The simulation results of the proposedreaction scheme were compared with those of reference mechanisms (GRI v3.0 and Konnov 0.5 version) as well as experimentaldata. Based upon simulation results, it can be concluded that the proposed mechanism shows good concordanceswith GR I3.0 mechanism especially in the prediction of temperature, pressure, and major product species (H2O, CO2) profilesat stoichiometric conditions (= 1.0). Although, there are some discrepancies among each predicted profile, the proposeddetailed mechanism is good to describe the oxidation of natural gas in IC engine. The experimental data also showed favorableresults for prediction of major product species (CO2, H2O & CO) at various engine operating speeds in idle mode

Emerging opportunities for hybrid perovskite solar cells using machine learning

While there are several bottlenecks in hybrid organic–inorganic perovskite (HOIP) solar cell production steps, including composition screening, fabrication, material stability, and device performance, machine learning approaches have begun to tackle each of these issues in recent years. Different algorithms have successfully been adopted to solve the unique problems at each step of HOIP development. Specifically, high-throughput experimentation produces vast amount of training data required to effectively implement machine learning methods. Here, we present an overview of machine learning models, including linear regression, neural networks, deep learning, and statistical forecasting. Experimental examples from the literature, where machine learning is applied to HOIP composition screening, thin film fabrication, thin film characterization, and full device testing, are discussed. These paradigms give insights into the future of HOIP solar cell research. As databases expand and computational power improves, increasingly accurate predictions of the HOIP behavior are becoming possible

Application of Fragment-Based Screening to the Design of Inhibitors of Escherichia coli DsbA

The thiol-disulfide oxidoreductase enzyme DsbA catalyzes the formation of disulfide bonds in the periplasm of Gram-negative bacteria. DsbA substrates include proteins involved in bacterial virulence. In the absence of DsbA, many of these proteins do not fold correctly, which renders the bacteria avirulent. Thus DsbA is a critical mediator of virulence and inhibitors may act as antivirulence agents. Biophysical screening has been employed to identify fragments that bind to DsbA from Escherichia coli. Elaboration of one of these fragments produced compounds that inhibit DsbA activity in vitro. In cell-based assays, the compounds inhibit bacterial motility, but have no effect on growth in liquid culture, which is consistent with selective inhibition of DsbA. Crystal structures of inhibitors bound to DsbA indicate that they bind adjacent to the active site. Together, the data suggest that DsbA may be amenable to the development of novel antibacterial compounds that act by inhibiting bacterial bacterial virulence,drug design, EcDsbA,fragment-based drugdiscovery,medicinal chemistr