Effect of Substrate Temperature on Spray Deposited Zinc Sulphide Thin Films

Thin films of Zinc sulphide (ZnS) on glass substrate were prepared by chemical spray pyrolysis technique using precursor solutions of zinc chloride and n–n dimethyl thiourea at substrate temperatures of 598 K and 623 K. X ray diffraction analysis exposed the polycrystalline nature with growing crystallinity with respect to substrate temperature. The preferential orientation growth of ZnS compound increased with relatively higher substrate temperature having hexagonal structure along (019) plane. At 623 K, The size of the Zinc sulphide crystallite with nano dimension was determined using the Full Width Half Maximum value of the Bragg peak. The surface morphology had been analyzed using scanning electron microscope. The compositional analysis had been observed by Energy Dispersive Analysis by X-ray spectrum. FTIR study had been carried out for the bond evaluation

Deposition and Characterization of Spray Pyrolytic Cadmium Sulphide Thin Film

Precursor solutions of cadmium chloride (CdCl2) and thiourea [(NH2)2CS] were used to prepare Cadmium sulphide (CdS) thin film on glass substrate by chemical spray pyrolysis technique at the substrate temperature of 623 K. The structural properties of the film were investigated through the analysis of X-ray diffraction pattern (XRD), scanning Electron Microscope (SEM) and Energy Dispersive Analysis (EDAX).The growth of crystal became stronger and more oriented as seen in the X-ray diffraction pattern. This diffraction analysis revealed the polycrystalline nature and the preferential orientation growth of CdS compound having hexagonal structure along (002) plane. The size of the cadmium sulphide crystallite with nano dimension 27.73 nm was determined using the Full Width Half Maximum value of the Bragg peak. The surface morphology had been observed on the surface of this film using scanning electron microscope. The stoichiometric property was determined using Energy Dispersive Analysis X ray spectrum and the optical absorption and transmittance spectra have been recorded for this film in the wavelength range 300–1100 nm. The optical band gap energy is found to be 2.3 eV with direct allowed band-to-band transition for film deposited at 623 K

Circular dichroism studies of α-aminoisobutyric acid-containing peptides: Chain length and solvent effects in alternating Aib-L-Ala and Aib-L-Val sequences

The CD spectra of the peptides Boc-X-(Aib-X)n-OMe (n = 1, 2, 3) and Boc-(Aib-X)5-OMe, where X = L-Ala or L-Val have been examined in several solvents. The X = Ala and Val peptides behave similarly in all solvents, suggesting that the Aib residues dominate the folding preferences of these peptides. The decapeptides adopt helical conformations in methanol and trifluoroethanol, with characteristic negative CD bands at 222 and 205 nm. In the heptapeptides, similar spectra with reduced intensities are observed. Comparison with nmr studies suggest that estimates of helical content in oligopeptides by CD methods may lead to erroneous conclusions. The pentapeptides yield solvent-dependent spectra indicative of conformational perturbations. Peptide association in dioxane results in an unusual spectrum with a single negative band at 210 nm for the decapeptides. Disaggregation is induced by the addition of methanol or water to dioxane solutions. Aggregation of the heptapeptides is less pronounced in dioxane, suggesting that a critical helix length may be necessary to promote association stabilized by helix dipole-dipole interactions

Phase Change Material on Augmentation of Fresh Water Production Using Pyramid Solar Still

The augmentation of fresh water and increase in the solar still efficiency of a triangular pyramid is added with phase change material (PCM) on the basin. Experimental studies were conducted and the effects of production of fresh water with and without PCM were investigated. Using paraffin as the PCM material, performance of the solar still were conducted on a hot, humid climate of Chennai (13°5′ 2" North, 80°16′ 12"East), India. The use of paraffin wax increases the latent heat storage so that the energy is stored in the PCM and in the absence of solar radiation it rejects its stored heat into the basin for further evaporation of water from the basin. Temperatures of water, Tw, Temperature of phase change material, TPCM, Temperature of cover, Tc were measured using thermocouple. Results show that there is an increase of maximum 20%, in productivity of fresh water with PCM

Ethyl 4-(3-hydroxy­phen­yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa­hydro­quinoline-3-carboxyl­ate

In the mol­ecular structure of the title compound, C21H25NO4, the dihydro­pyridine ring adopts a flattened boat conformation while the cyclo­hexenone ring is in an envelope conformation. In the crystal structure, mol­ecules are linked into a two-dimensional network parallel to (10) by N—H⋯O and O—H⋯O hydrogen bonds. The network is generated by R 4 4(30) and R 4 4(34) graph-set motifs

Ethyl 2-acetyl-3-(4-chloro­anilino)butanoate

The title compound, C14H18ClNO3, adopts an extended conformation, with all of the main chain torsion angles associated with the ester and amino groups trans. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds are observed

1,1′-(p-Phenyl­enedimethyl­ene)dipiperidin-4-one

In the mol­ecule of the title compound, C18H24N2O2, the piperidine rings are in chair conformations. The crystal structure is stabilized by inter­molecular C—H⋯O hydrogen bonding. There are neither C—H⋯π nor π–π inter­actions in the structure

High pressure studies on YNi<SUB>2</SUB>B<SUB>2</SUB>C and LuNi<SUB>2</SUB>B<SUB>2</SUB>C: ADXRD, thermoelectric power, resistivity, and electronic structure

The electronic and structural behaviour of YNi2B2C and LuNi2B2C at high pressures were investigated by electrical resistivity, thermoelectric power (TEP), and angle dispersive X-ray diffraction measurements and by electronic band structure calculations. The pressure variation of TEP shows a peak around 2 GPa in YNi2B2C. However, the X-ray powder diffraction does not show any structural transition up to 16.4 GPa. The equation of state of YNi2B2C yielded a relatively high bulk modulus of 200 GPa. The observed peak in TEP and the pressure variation of the superconducting transition temperature can be correlated with different components of the electronic density of states. The universal equation of state shows deviation from linearity around 1.5 GPa pressure and correlates well with the TEP peak