Thermoelectric power of ferroelectric potassium vanadate,cesium vanadate,lithium vanadate and their solid solutions

The thermoelectric power of the vanadates of potassium, cesium and lithium and their solid solutions was measured in the temperature range covering their transition points. The thermoelectric power measurement was carried out by the two-electrode technique for pellets of polycrystalline ceramic samples. The thermoelectric power increased with temperature initially, then decreased attaining a zero value at the transition temperature. As the concentration of KVO₃ increased the thermoelectric power decreased for the solid solutions (K _x − Cs_1−x )VO₃, whereas the thermoelectric power increased with increase in concentration of KVO₃ for the solid solutions (K _x − Li_1−x )VO₃. Vanadates of potassium, cesium, and lithium and their solid solutions showedP type semiconductor behaviour in ferroelectric state andn type semiconductor behaviour in paraelectric region.     

Studies on dielectric hysteresis of ferroelectric sodium vanadate,rubidium vanadate,cesium vanadate and their solid solutions

The dielectric hysteresis property of sodium vanadate, rubidium vanadate, cesium vanadate and their solid solutions has been studied in the temperature range covering their transition points. The hysteresis loop method is used for coercive field measurements. It was observed that the coercive field decreases with increasing temperature, and that it also decreases with increasing sodium concentration in the solid solutions (sodium-rubidium) vanadate and (sodium-cesium) vanadate.     

Naloxone-induced withdrawal in patients with buprenorphine dependence

Naloxone-induced withdrawal was studied in seven patients currently dependent only on injecting buprenorphine, within 3 to 6 hours of their last dose. Withdrawal severity began to rise from 5 minutes and reached a peak at 60 minutes after 1.2 mg naloxone given intravenously. The mean withdrawal severity score was significantly higher at 30, 60 and 90 minutes compared to the baseline. The most frequent withdrawal signs and symptoms were mydriasis, systolic hypertension, tachypnoea, muscle pains, yawning, anxiety, restlessness and craving.     

Reactions of ketene dithioacetal for a new versatile synthesis of 4,5-substituted 3-aminothiophene-2-carboxylate derivatives

Poly substituted 3-aminothiophenes were successfully synthesized in good yields by using a one-pot protocol via ketene S,S-acetal as an intermediate in basic medium (K₂CO₃/N,N-dimethylformamide) followed by Dieckmann condensation with ethyl bromoacetate. Further, chemistry of thiophenes was explored using active functional groups such as C₃–NH₂, C₄–CN and C₅–SCH₃ on the thiophene nucleus.

Synthesis of ethyl 3-acetamido-4-cyano-5-(methylthio)thiophene-2-carboxylate derivatives and ethyl 3-amino-4-carbamoyl-5-(methylthio)thiophene-2-carboxylate derivatives.     

Synthesis and characterization of self-assembled nanofiber-bundles of V2O5: their electrochemical and field emission properties

High-quality self-assembled V(2)O(5) nanofiber-bundles (NBs) are synthesized by a simple and direct hydrothermal method using a vanadium(v) hydroxylamido complex as a vanadium source in the presence of HNO(3). The possible reaction pathway for the formation of V(2)O(5) NBs is discussed and demonstrated that HNO(3) functions both as an oxidizing and as an acidification agent. V(2)O(5) NBs are single-crystals of an orthorhombic phase that have grown along the [010] direction. A bundle is made of indefinite numbers of homogeneous V(2)O(5) nanofibers where nanofibers have lengths up to several micrometres and widths ranging between 20 and 50 nm. As-prepared V(2)O(5) NBs display a high electrochemical performance in a non-aqueous electrolyte as a cathode material for lithium ion batteries. Field emission properties are also investigated which shows that a low turn-on field of ～1.84 V μm(-1) is required to draw the emission current density of 10 μA cm(-2).     

Effect of thermal annealing on properties of zinc selenide thin films deposited by chemical bath deposition

Zinc selenide films have been deposited on glass substrate by chemical bath deposition method. The resultant films were annealed up to 473 K temperature. The structural properties of zinc selenide thin films have been investigated by X-ray diffraction techniques. The X-ray diffraction spectra showed that zinc selenide thin films are polycrystalline and have a cubic structure. The most preferential orientation is along the (111) direction for all films. The lattice parameter, grain size, and microstrain were calculated and correlated with annealing temperature. The optical properties showed direct band gap values were found to be in the region of 2.69–2.81 eV. The electrical studies shows conductivity increases with increase in annealing temperature. The optoelectric and structural data are discussed from the point of applications based on achieving high performance devices.     

Extraction of p-coumaric acid from agricultural residues and separation using ‘sugaring out’

We investigated the extraction of para-coumaric acid (pCA) from different agriculture residues (corn stover, sugarcane bagasse, sorghum stalk, pearl millet stalk, green gram shell, groundnut shell, sesame shell) using sugarcane bagasse alkaline hydrolysis and separation of pCA using sugaring out - a new phase separation method. Primary screening of different feed stocks was by alkaline hydrolysis with 2M NaOH for 6 h at room temperature. Sugarcane baggase resulted into significant amount of pCA (1.1 g/L) and small amount of ferulic acid (FA) (0.23 g/L). The optimized alkaline hydrolysis conditions (2 M NaOH and 16 h) resulted into maximum pCA release of 2.0 g/L. The pCA was separated from alkaline hydrolysate using sugaring out, a two phase separation method that results in aqueous phase and the organic solvent (acetonitrile) phase. Sugaring-out separated more than 90% of the pCA from the alkaline hydrolysate. Results of HPLC using standard pCA and FA showed that the main component of the separated top (organic solvent) phase was pCA rather than FA.     

Sensitivity analysis of vibro-acoustic systems in statistical energy analysis framework

The main objective of this paper is to present first and second-order sensitivity analysis of vibro-acoustic systems in the statistical energy analysis (SEA) frame work. Equations for computing these sensitivities for a general SEA model are obtained from two different approaches: (1) direct method and (2) adjoint method. The above equations are applied to a simple model of three plates, joined in the form of a ‘Z’, to minimize the total energy of one of the plates. It has been verified that these approaches lead to the same results and the difference between them is only with respect to the computational efficiency. The design sensitivity results calculated from the proposed analytical methods are compared with those obtained from the finite difference method, which show good agreement. The results of this paper can be useful to optimization of vibro-acoustic systems at the drawing board stage in the SEA framework.