Single Frame Image super Resolution using Learned Directionlets

In this paper, a new directionally adaptive, learning based, single image super resolution method using multiple direction wavelet transform, called Directionlets is presented. This method uses directionlets to effectively capture directional features and to extract edge information along different directions of a set of available high resolution images .This information is used as the training set for super resolving a low resolution input image and the Directionlet coefficients at finer scales of its high-resolution image are learned locally from this training set and the inverse Directionlet transform recovers the super-resolved high resolution image. The simulation results showed that the proposed approach outperforms standard interpolation techniques like Cubic spline interpolation as well as standard Wavelet-based learning, both visually and in terms of the mean squared error (mse) values. This method gives good result with aliased images also.Comment: 14 pages,6 figure

Design and Synthesis of Peripherally Selective Endocannabinoid Enzyme Inhibitors for Ocular Indications

Peripherally selective compounds have been found to stimulate endocannabinoid receptor activity, which has been observed to have positive physiological effects such as ocular wound healing and inflammation control. The activation of the cannabinoid 1 receptor via binding of the endogenous ligands, anandamide and 2-arachidonoylglycerol, has been indicated to elicit these effects. Both ligands are controlled by two hydrolase enzymes, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), which can be targeted for therapeutic inhibition. Sulfonamide derivatives of JZL195 containing carbamate functionalities in the southern region of the inhibitor compounds were produced using novel carbamate exchange reactions. Polar functionalities were introduced to increase their high topological surface area (TPSA) to prevent the crossing of these inhibitors through the blood-brain barrier (BBB), which in turn prevents any potential adverse effects on the central nervous system. The potency of each compound was measured using inhibitor screening assay kits for FAAH and MAGL

A single molecule switch based on two Pd nanocrystals linked by a conjugated dithiol

Tunneling spectroscopy measurements have been carried out on a single molecule device formed by two Pd nanocrystals (dia, $\sim$5 nm) electronically coupled by a conducting molecule, dimercaptodiphenylacetylene. The I-V data, obtained by positioning the tip over a nanocrystal electrode, exhibit negative differential resistance (NDR) on a background M-I-M characteristics. The NDR feature occurs at $\sim$0.67 V at 300 K and shifts to a higher bias of 1.93 V at 90 K. When the tip is held in the middle region of the device, a coulomb blockade region is observed ($\pm\sim$0.3 V).Comment: Accepted in Praman

Enhanced optical limiting in nanosized mixed zinc ferrites

Optical limiting performance of zinc ferrite, nickel zinc ferrite, and copper zinc ferrite nanoparticles is investigated at 532 nm using 5 nanosecond laser pulses. Enhanced optical limiting is observed in the mixed zinc ferrites, which is attributed to the relative longevity of self-trapped charge transfer states. Samples exhibit absorption saturation followed by a rapid onset of optical limiting as the input fluence is increased. This is advantageous in applications where detector sensitivity should be retained at the maximum value until the input fluence approaches the detector damage regime. The Z-scan results are compared to those measured in C-60

Hydrogen bonding patterns in the cocrystals of 5-nitrouracil with several donor and acceptor molecules

Cocrystals of 5-nitrouracil with solvent molecules, dioxane, pyridine, DMSO, formamide and ethanol as well as with piperazine, N, N'-dimethylpiperazine, 3-aminopyridine and diazabicyclo [2.2.2]octane obtained by deliberate inclusion, have been examined by X-ray crystallography. The tape structure found in the parent centric form of nitrouracil is retained with some modifications in the cocrystals with dioxane, piperazine, diazabicyclo [2.2.2]octane, N,N'-dimethylpiperazine, pyridine and DMSO, with the guest molecules forming alternate tapes. In cocrystals involving formamide, ethanol and 3-aminopyridine, the molecular tapes exhibit mixed compositions. The observed bonding patterns have been classified into six schemes. Interestingly, quadruple type hydrogen bonding patterns are seen in cocrystals containing 3-aminopyridine or ethanol and water, while a network of acyclic tetrahedral pentamers of water is found in the cocrystal containing diazabicyclo [2.2.2]octane and water

Ferroelectric ceramic dispersion to enhance the beta phase of polymer for improving dielectric and ferroelectric properties of the composites

Ferroelectric ceramic-polymer composites consisting of Poly Vinyledine Fluoride-Hexa Fluoro Propylene (PVDF-HFP) as polymer host and 0.5Ba(Zr0.2Ti0.8)O-3-0.5(Ba0.7Ca0.3)TiO3(BZT-BCT) ceramics as filler were prepared using solution casting technique. These composites are characterized for structural, microstructural, vibrational, optical, dielectric and ferroelectric properties at various experimental conditions. The electroactive beta phase fraction (observed from XRD and FTIR analysis) increases as the filler concentration increases up to 20 wt% of BZT-BCT and above that its value decreases. FTIR results were analyzed to understand the mechanism of enhancement of beta phase by the interaction between negatively surface charged ions of filler with the CH(2)dipole of polymer matrix. UV-visible spectroscopy also employed to confirm polymer-ceramic filler interaction. Variation of the dielectric constant with different filler concentrations is explained using the percolation theory. Finally, the interplay between the functional properties and the beta phase is discussed in detail

Nonlinear light transmission through oxide-protected Au and Ag nanoparticles: an investigation in the nanosecond domain

Stable Au and Ag nanoparticles protected with TiO2, ZrO2, and SiO2 shells show saturable absorption when excited with moderately energetic nanosecond pulses at 532 nm, but exhibit strong optical limiting at higher intensities. The behavior is explained in terms of the induced optical nonlinearity and nonlinear light scattering. The inherent stability of the core-shell structure renders a high laser damage threshold to these materials, making them promising candidates for high energy optical limiting

Recent Advances in Optical Limiting Properties of Fluorinated Graphene Oxides

There is a substantial interest in finding materials with high nonlinear optical (NLO) properties of materials because of its attractive applications in optical limiting for safety protections. In an effort to develop highly performing optical limiting materials, recently we have found that fluorination of graphene oxides leads to improvement in their NLO properties

Charge density analysis of two proton transfer complexes: understanding hydrogen bonding and determination of in-crystal dipole moments

An experimental charge density study has been carried out on proton-transfer complexes exhibiting nonlinear optical (NLO) properties-melaminium tartrate monohydrate and L-asparaginium picrate employing high-resolution X-ray diffraction at 100 K. Both the complexes crystallize in non-centric space group P21 and the structures exhibit interesting patterns of N-H...O and O-H...O hydrogen bonding. Experimental determination of the dipole moment (μ) for the asymmetric unit reveals that for both the crystals, there is a large cooperative enhancement in the crystalline μ arising essentially due to hydrogen bond mediated charge transfer between the melaminium ion and the L-tartrate in one case, between the Lasparaginium ion and the picrate in the other complex. We have additionally performed theoretical calculations at the density functional theory (DFT) level to understand the origin of enhancement of the dipole moments in the two systems