Enhanced Biogas Production Of A Revamped Fixed Film Anaerobic Digester On Raw Spent Wash- A Case Study

In the present scenario, the cost of conventional energies has increased at a rapid rate due to manifold increase in their consumption. Renewable sources of energy are our best option for sustainable and pollution free development. One of the chief renewable sources of energy is biogas. The biogas is produced as by product of anaerobic digestion of organic substrate. Raw Spent Wash (RSW) is generated as effluent from distilleries and is a high organic content wastewater with potential for tremendous quantity of biogas generation via anaerobic digestion. In the present study biogas generation from a revamped fixed media reactor was evaluated for biogas production using RSW as substrate. The revamped digester was able to achieve its designed performance and achieved an average COD reduction of 65%, with the average biogas production of 22343 m3/d. The biogas production was 3535 m3/day higher than design values, indicating the superiority of reactor system in treating the effluent. The present study found that media based reactor is highly efficient,  reducing pollution loads from the effluent of the distillery and can additionally produce biogas in surplus quantities providing a double benefit of clean source of energy and financial savings to the industry

Growth and Characterization of Na0.5Bi0.5TiO3 Thin Films with BaTiO3 Buffer Layer (Study of Au/Na0.5Bi0.5TiO3/BaTiO3/Pt Capacitor)

Lead free bilayer capacitor structure has been fabricated as a combination of sodium bismuth titanate (Na0.5Bi0.5)TiO3 (NBT) thin films with barium titanate, (BaTiO3) (BT) buffer layer in situ using pulsed laser deposition (PLD). PLD control parameters have been optimized using Taguchi approach to obtain good quality NBT and BT thin films. It has been observed that dielectric properties of NBT thin films enhanced by inserting BT buffer layer. This improvement in the dielectric properties of NBT thin films have been discussed in relation to the effect of the buffer layer on the structure, microstructure and interface of the NBT/BT multilayer capacitor

Growth of pseudocubic perovskite-type SrRuO3 thin films on quartz substrate using pulsed laser deposition method

Strontium ruthenium oxide (SrRuO3) thin films have been grown using pulsed laser deposition technique on silicon, Pt coated silicon and quartz substrates. The effect of substrate temperatures on the structural, microstructure, and electrical properties of the SrRuO3 films on quartz substrate has been investigated using XRD, SEM, AFM and four-probe method, respectively. The lowest resistivity at room temperature for the SrRuO3 thin film on quartz substrate has been achieved at substrate temperature of 700 A degrees C. Furthermore, the comparisons of SrRuO3 thin films deposited on various substrates have been done with respect to structural, microstructural and electrical properties. XRD patterns exhibit that all thin films are a single phase, pseudo-cubic perovskite structure. Study of surface morphology shows that grain size and roughness varies with respect to substrate. It is observed that SrRuO3 thin films yield larger grain size and root mean square roughness on Pt/Si substrate. Investigation of electrical properties shows that SrRuO3 thin films can serve the purpose of the bottom electrode in dielectric and ferroelectric devices

Influence of oxygen gas pressure on phase, microstructure and electrical properties of sodium bismuth titanate thin films grown using pulsed laser deposition

Na0.5Bi0.5TiO3 (NBT) thin films were grown with oxygen gas pressure in the range of 5 Pa and 100 Pa. NBT thin film grown at 30 Pa shows improved properties when compared to films grown at other pressures. This film exhibits single phase and good crystallinity. It has the highest dielectric constant of 754 and lowest dielectric loss of 0.21 at 1 kHz. It has the lowest leakage current of 2 x 10(-6) A/cm(2) measured at 50 kV/cmelectric field. The values of remnant polarization and coercive field, which were measured at room temperature, 10 V and 1 kHz, are 20 mu C/cm(2) and 160 kV/cm respectively. Fatigue study reveals that remnant polarization (+ Pr and -Pr) decreases by 15% after 108 switching cycles. (C) 2015 Elsevier B.V. All rights reserved

Inverse Elastostatics Boundary Element Approach Applied To Nondestructive Evaluation

The elastostatics boundary element method is applied in an inverse problem approach to the nondestructive detection of subsurface cavities in structures. The approach relies on the overspecification of the boundary conditions at the exposed surface. The traction is specified there, and displacements are used as additional data for solving the inverse problem. The displacements are numerically simulated in this study; however in practice they may be experimentally determined, for instance by the laser speckle photography technique. In the developed iterative procedure, an initial guess is made for the shape of the cavity and a grid pattern is laid out

Structural and electrical properties of sodium bismuth titanate (Na0.5Bi0.5TiO3) thin films optimized using the Taguchi approach

Controllable Pulsed Laser Deposition (PLD) parameters have been optimized to grow sodium bismuth titanate (Na0.5Bi0.5TiO3) (NBT) thin films. Target to substrate distance, background gas pressure, substrate temperature, laser fluence, laser rate of repetition, annealing time and NBT targets with and without excess Bi have been chosen as the parameters using a Taguchi L-18 orthogonal array. Taguchi's Signal-to-Noise (S/N) ratios and analysis of variance (ANOVA) tools highlight the relevance of each parameter, and also yield the optimal setting of the parameters. The dominant parameters affecting dielectric properties are oxygen gas pressure and substrate temperature, whereas the distance between target to substrate and laser fluence appear as significant parameters. Fine tuning experiments and a subsequent verification experiment using the dominant and significant parameters result in the best values for the dielectric constant of 735, dielectric loss of 0.07 at 1 kHz and remnant polarization of 21.42 mu C/cm(2). (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Impedance and AC conductivity study of nano crystalline, fine grained multiferroic bismuth ferrite (BiFeO3), synthesized by microwave sintering

In this paper, major reduction in sintering time, temperautre and significant improvement over final density of sitnered sample is reported for the microwave sintered nanocrystalline BiFeO3 (BFO) ceramic. Also, different sintering time and temperatures have been used to tailor the grain size and the final density of the resulting BFO ceramics synthesized from phase pure BFO nanoparticles ((d) over bar approximate to 10 nm). Microwave sintering resulted in reducing the sintering time substantially (by 1h), and has resulted in submicron sized grains and high resistivity similar to 1.8 G Omega-cm. The AC conductivity is seen to follow the Jonscher's power law behavior, suggesting correlated barrier hopping (CBH) mechanism in the sample. The role of oxygen vacancies at high temperature, due to volatility of bismuth, in dielectric and conductivity behavior is also discussed. Further, the sample displayed dielectric anomaly near magnetic transition temperature (similar to 180 degrees C) indicating bearing of magnetic moments on the dielectric properties. Using Impedance Spectroscopy (IS) we have established, the electrical heterogeneity of the ceramic BFO reavealing semiconducting nature of grains and insulating nature of grain boundary. This, formation of network of insulating grain boundaries and semiconducting grains could lead to formation of internal barrier layer capacitance (IBLC) leading to high dielectric constant in microwave sintered BFO. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License

Structural and Electrical Characterization of La and Mn Co-Substituted Bismuth Ferrite Thin Films

Bismuth ferrite thin films with 10% La and 5% Mn (BLFMO) have been deposited using Pulsed laser deposition. It is found that oxygen pressure has pronounced effect on the structural and electrical properties of BLFMO thin films. The leakage current density increases with the oxygen pressure. At 0.007 mbar, the leakage current density is found to be in the order of 10(-7)A/cm(2) at 200kV/cm. The remnant polarization is 73C/cm(2) at 200kV/cm. Fatigue endurance has been studied for optimized film and found that films are almost fatigue free after 10(8) pulses. There is only 3% change in the polarization up to 10(6) seconds as revealed by retention test