RuCl3 Catalyzed and Uncatalyzed Oxidative Decolorization of Acid Orange 7 Dye with Chloramine-B in Acid Medium: Spectrophotometric, Kinetic and Mechanistic Study

Acid orange 7, chemically known as sodium 4-[(2E)-2-(2-oxonaphthalen-1-ylidene)hydrazinyl]benzenesulfonate, is extensively used for dyeing textiles, paper and leather. The discharge of wastewater containing this dye, causes environmental and health related problems. Therefore, in the present research, we have developed optimum conditions for the facile oxidative decolorization of this dye with sodium N-chlorobenzenesulfonamide or chloramine-B (CAB). The kinetics and mechanism of oxidative decolorization of acid orange 7 dye with CAB in acidic medium have also been studied spectrophotometrically at 303 K in the presence and absence of RuCl3 catalyst. Under similar experimental conditions, the reaction exhibits a first-order dependence of rate each on [CAB]o and [dye]o, and an inverse-fractional-order dependence on [H+] for both the RuCl3 catalyzed and uncatalyzed reactions. The order with respect to RuCl3 is fractional. Activation parameters have been computed. Dielectric effect is negative in both the cases. Oxidation products of the acid orange 7 dye are identified as 1,2-naphthoquinone and benzenesulfonic acid by GC–MS data. The RuCl3 catalyzed reaction is about four fold faster than the uncatalyzed reaction. The chemical oxygen demand value of the dye was determined. The mechanistic pathways and kinetic modelings have been computed based on experimental results. The developed oxidative decolorization method is expected to be helpful to treat acid orange 7 dye present in wastewater after suitable modifications

Design, Development and Thermal Analysis of Reusable Li-Ion Battery Module for Future Mobile and Stationary Applications

open access articleThe performance, energy storage capacity, safety, and lifetime of lithium-ion battery cells of different chemistries are very sensitive to operating and environmental temperatures. The cells generate heat by current passing through their internal resistances, and chemical reactions can generate additional, sometimes uncontrollable, heat if the temperature within the cells reaches the trigger temperature. Therefore, a high-performance battery cooling system that maintains cells as close to the ideal temperature as possible is needed to enable the highest possible discharge current rates while still providing a sufficient safety margin. This paper presents a novel design, preliminary development, and results for an inexpensive reusable, liquid-cooled, modular, hexagonal battery module that may be suitable for some mobile and stationary applications that have high charge and or discharge rate requirements. The battery temperature rise was measured experimentally for a six parallel 18650 cylindrical cell demonstrator module over complete discharge cycles at discharge rates of 1C, 2C and 3C. The measured temperature rises at the hottest point in the cells, at the anode terminal, were found to be 6, 17 and 22 °C, respectively. The thermal resistance of the system was estimated to be below 0.2 K/W at a coolant flow rate of 0.001 Kg/s. The proposed liquid cooled module appeared to be an effective solution for maintaining cylindrical Li-ion cells close to their optimum working temperature

Failure prediction of adhesively bonded lap joints between metal and composite adherends

Most of the modern civilian or military aircrafts use advanced composite materials for their primary structural components, in addition to metals. The components are joined together by using either fastener or adhesively bonded joints. But with the introduction of composite materials in aircraft industries, adhesively bonded lap joints are most preferred. This is due to the fact that they develop smooth load transfer and fewer points of stress concentration as compared to fastener joints. The failure prediction of such joints is extremely important, to avoid catastrophic failures during aircraft service period. In the present investigation, an adhesively bonded lap joint between metal-composite (i.e., Al 2024-T3/CFRP) adherends bonded with Redux 319-A adhesive has been analyzed using finite element method considering geometric non-linearity and incorporating adhesive material nonlinear behavior. The failure has been predicted using plastic zone size criterion of adhesive material, which is innovative approach of this study. Also, experimental program is carried out on such joints to correlate with the predicted failure load obtained from numerical model. In this study, the failure of joint is assumed to take place due to adhesive failure only. Plastic zone size in adhesive at failure load of joint is taken as 15 % of the lap length as established from the previous work of the authors. It is observed that the failure load of the adhesively bonded lap joint between composite-metal adherends as obtained from numerical model is well compared with that obtained from experimental study. Results are discussed

Design and development of fly-back converter with buck-boost regulator for DC motor used in electric vehicle for the application of renewable energy

This paper presents design and development of fly-back converter with buck-boost regulator for dc motor used in electric vehicle for renewable energy application. An electric vehicle working with DC motor energized from fly-back converter with buck-boost regulator, the energy generated by renewable sources like solar energy and wind energy. The present work depicts six phase generator to generate the power from wind fans, and then six phase converter (rectifier) is used to convert AC to DC. The use of fly-back converter in the power conversion system ripple voltages can be minimized and used to drive the electric vehicle. © 2017 IEEE

Optimization of feed force, tangential force and surface roughness by using grey based Taguchi method

This study investigated the optimization of turning process parameters such as cutting speed, feed rate and depth of cut on EN-19 material using the Grey Relational Analysis (GRA) method. Twenty seven experimental runs based on an orthogonal array of Taguchi method were performed. The feed force (F X), tangential force (FY) and surface roughness (R a) were selected as the quality targets. An optimal parameter combination of the turning operation was obtained using GRA. By analyzing the grey relational grade matrix, the degree of influenced for each controllable process factor onto individual quality targets can be found. The depth of cut is identified to be the most influence on feed force and tangential force, and feed rate is the most influential factor to the surface roughness. Additionally, the analysis of variance (ANOVA) was also applied to identify the most significant factor; the depth of cut is the most significant controlled factor for the turning operation according to the weighted sum grade of the feed force, tangential force and surface roughness

Simulation and implementation of FPGA based hybrid asymmetric multilevel inverter

This work focuses on proposing a new structure for asymmetric multilevel inverter. In the proposed topology, a switched capacitor (SC) and conventional series inverter are combined and connected in cascade. The proposed multilevel inverter finds its application in photovoltaic inverters which has numerous advantages. Firstly, it converts power for AC requirements from comparatively low DC voltage sources and with lower number of switching devices. Second, with the removal of transformers normally used for stepping up the voltage of each inverter stage the weight, volume and size of the whole system is reduced as the proposed topology can double the input voltage without a transformer. Symmetrical step control method (SSCM) and fundamental switching frequency method (FSFM) are applied to this proposed topology to actuate the power electronic switches for effective control and monitoring of voltage levels generated at the output. The simulation is executed using MATLAB/SIMULINK software. It was found that FSFM modulation technique results in a lower value of Total Harmonic Distortion (THD). The switching strategy is implemented with an FPGA device for the experimental prototype. The simulation and experimental result of single-phase 25-level inverter is given to demonstrate the precise operation of the suggested topology

Cytological Changes during Oogenesis in Exorista sorbillans (Diptera: Tachinidae)

The cytological changes and growth rate of nurse cell nuclei, the oocyte nucleus, and the egg chamber during 14 stages of egg development in E. sorbillans Wiedemann are described. Stages 1-3 are mitotically active, resulting in the formation of one oocyte and 15 nurse cells. The visible nonbanded polytene chromosomes are formed at stage 3 in 32n nuclei of smaller nurse cells and 64n nuclei of larger nurse cells. The larger nurse cell nuclei attain a maximal ploidy of 1024n at stage 10. Soon after disintegration of the polytene chromosomes, the nurse cells at stage 6 synthesize the nuclear proteins and transfer them to the developing oocyte, which grows rapidly from stages 11 to 13. At stages 13 and 14, the nurse cells disintegrate and the oocyte matures with chorion, aeropyles, operculum, micropyle, and hatching pleat. At the end of stage 14, the matured oocyte has enlarged to 137,651.92 times that of the oogonium. The results are compared with those from allied species

Studies on External Bremsstrahlung in thick target compounds

Most of external Bremsstrahlung (EB) works of beta have been carried out using only metal as a thick target but using compound as a thick target is lacking. Present study is made to (i) follow the interpolation technique to extend the existing theory from elements to compounds (ii) focus on various compounds which can be used as targets for incident beta particles to produce EB spectrum (iii) compare experimental results with the theory suitably extended to compound. Experiment has been carried out in a good geometry set up. In the present study, beta source such as 204Tl (0.766 MeV) and thick target compounds, PbCl2 and CdO have been used. After carrying out the unfolded procedure, measured spectrum has been compared with the theoretical spectrum. © 2007 Elsevier B.V. All rights reserved