Synthesis, characterization and photocatalytic application of ZnWO4/ZrO2 nanocomposite towards degradation of methyl orange dye

Visible light active ZnWO4/ZrO2 nanocomposite was prepared via hydrothermal method. The nanocomposite was characterized by UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning Electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM) techniques. The XRD results showed that average particle size of ZrO2, ZnWO4 and ZnWO4/ZrO2 were found to be 29.20 nm, 23.78 nm and 20.14 nm respectively and the phase structure for ZrO2 and ZnWO4 in the composite was Rhombohedral and Monoclinic respectively. The UV–vis absorption spectra of the ZnWO4/ZrO2 nanocomposite noticeably shifted to the visible light region compared to that of the ZrO2. The prepared photocatalyst were composed of plate and spongy sphere with little agglomeration was seen from SEM result. The photocatalytic activities of the prepared nanocomposite was evaluated for the degradation of methyl orange (MO) under visible light irradiations. The effect of operational parameters such as initial dye concentration, pH, catalyst concentration and irradiation time have been investigated in detail. The photocatalytic degradation efficiency of ZnWO4/ZrO2, ZnWO4 and ZrO2 for 95%, 72% and 60 % respevtively. The high photocatalytic activity can be attributed to stronger absorption in the visible light region, a greater specific surface area, smaller crystal sizes, more surface OH groups, and to the effect of ZnWO4 doping, which resulted in a lower band gap energy

Antidandruff activity of Cassia auriculata and Cassia alata through fatty acids mediated inhibition of Malassezia furfur

Susceptibility of Malassezia furfur to certain medium chain fatty acids shed light onto novel strategies to control dandruff. This study explored antidandruff activity of the fatty acids and other bioactive compounds from flowers of Cassia auriculata and Cassia alata. The idea was supplementing the growth medium with fatty acids which are inhibitory to Malassezia so that plant-based antidandruff formulations could be developed based on the results. Chloroform and ethanolic flower extracts were tested there in vitro efficacy against M. furfur and the potential antidandruff compounds were identified by gas chromatography-mass spectrophotometry (GC-MS). Minimum inhibitory concentrations were determined for both the extracts and IC50 values of 50 and 88 µM for chloroform extract of C. auriculata and C. alata were recorded. For ethanol extract, IC50 values of 75 and 70 µM were exhibited by C. auriculata and C. alata, respectively. Inhibition of M. furfur through fatty acids from Cassia is the first report, and it is possible to include specific fatty acids in the growth media to inhibit the growth of Malassezia which could be later served as lead molecules in antidandruff formulations. Further, the presence of citronellol, pinitol, anthracenedione and chrysine in Cassia flower extracts and their antidandruff activity reported in this study needed further research on those compounds to formulate effective treatment of Malassezia associated diseases

Trimethyl­ammonium 2,6-dioxo-5-(2,4,6-trinitro­phen­yl)-1,2,3,6-tetra­hydro­pyrimidin-4-olate

In the title barbiturate salt (trivial name: trimethyl­ammonium 2,4,6-trinitro­phenyl­barbiturate), C3H10N+·C10H4N5O9 −, the asymmetric unit contains two sets of anion–cation moieties. The dihedral angle between the rings in the anions are 44.0 (3) and 45.7 (3)°. Adjacent anions are connected into ribbons along [100] through R 2 2(8) ring motifs formed by N—H⋯O hydrogen bonds involving the barbiturate rings. Attached to both sides of these ribbons via N—H⋯O hydrogen bonds are the trimethyl­ammonium cations. C—H⋯O hydrogen bonds are also observed

Estimation of Shape of Binary Polygonal Object from Scattered Field

Abstract—We present a method of estimating the shape of a weakly scattering binary convex polygonal object from the backscattered field. We use the concept scattering centers where it has been possible to model the scattered field as a sum of complex sinusoids. All corners of an object could be estimated with three or more illuminations, out of which at least two are in orthogonal directions. Using the amplitude of the sinusoids, we have also resolved the ambiguity in joining the corners when there are more than one object. Index Terms—Broadband illumination, diffraction tomography, pairing algorithm, shape estimation. I

Estimation of Shape of Binary Polygonal Object from Scattered Field

We present a method of estimating the shape of a weakly scattering binary convex polygonal object from the backscattered field. We use the concept scattering centers where it has been possible to model the scattered field as a sum of complex sinusoids. All corners of an object could be estimated with three or more illuminations, out of which at least two are in orthogonal directions. Using the amplitude of the sinusoids, we have also resolved the ambiguity in joining the corners when there are more than one object

A Study of Cramer-Rao Bounds on Object Shape Parameters From Scattered Field

We have studied the Cramer-Rao bounds (CRBs) on sire and orientation elf a known abject using the scattered (acoustic or electromagnetic) field. A circular array of transievers surrounding the object under test is proposed The CRBs are theoretically derived and compared with the mean square errors computed via Monte Carlo simulations. The CRBs are found to increase rapidly with wavelength. For reliable estimates, the wavelength of illumination must be smaller than the size of the object

Study of catalytic activity of ammonium dihydrogen orthophosphate in the synthesis of 3,4-dihydropyrimidin-2-(1<i style="">H</i>)-one

865-867Application of ammonium dihydrogen orthophosphate as a catalyst in the one pot synthesis of 5-ethoxycarbonyl-6-methyl-4-phenyl-3,4-dihydropyrimidin-2-(1H)-one by Biginelli condensation is reported. The effect of temperature and the presence of solvents such as ethanol, acetonitrile, toluene, chloroform, acetic acid, n-hexane, etc. on the activity of the catalyst are studied