Surface chemistry and adsorption mechanism of cadmium ion on activated carbon derived from Garcinia mangostana shell

A detailed surface characterizations and adsorption mechanism of Cd²⁺ on chemical activated carbon (CAC) prepared from Garnicia mangostana shell were investigated. The activation is accomplished in self-generating atmosphere using phosphoric acid as activating agent. The characterizations performed are elemental analysis, functional group identification, N₂ adsorption isotherm and surface charges. Adsorption mechanism of metal ion was tested using Cd²⁺ as model ion. CAC achieved BET surface area of 1,498 m²/g with a mixture of micro and mesopores. The point of zero charge is observed to be at pH 2.8 and the optimum pH for Cd²⁺ adsorption on CAC is 12. The adsorption isotherm followed the Freundlich model, and the adsorption kinetics was explained by pseudo-second order kinetic model. From thermodynamic studies, the adsorption was found to be physical adsorption. X-ray photoelectron spectroscopy (XPS) confirmed the adsorption of Cd²⁺ onto CAC as +2 oxidation state.     

Dielectric and conductivity studies on cobalt phthalocyanine tetramers

Electrically conductive organic and metalloorganic polymers are of great interest and they have applications in electronic, optical, photonic, photoelectric, electrochemical, and dielectric devices. Tetrameric cobalt phthalocyanine was prepared by conventional chemical method. The dielectric permittivity of the tetrameric cobalt phthalocyanine sample was evaluated from the observed capacitance values in the frequency range 100 KHz to 5 MHz and in the temperature range of 300 to 383°K. It is found that the system obeys the Maxwell Wagner relaxation of space charge phenomenon. Further, from the permittivity studies AC conductivity was evaluated. The values of AC conductivity and DC conductivity were compared. Activation energy was calculated. To understand the conduction mechanism Mott's variable range hopping model was applied to the system. The T^?1/4 behavior of the DC conductivity along with the values of Mott's Temperature (T₀), density of states at the Fermi energy N (E_F), and range of hopping R and hopping energy W indicate that the transport of charge carriers are by three‐dimensional variable range hopping. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2529–2535, 2004     

Design of artificial neuron controller for STATCOM in dSPACE environment

Reactive power compensation is an important issue in the control of electric power system. Reactive power from the source increases the transmission losses and reduces the power transmission capability of the transmission lines. Moreover, reactive power should not be transmitted through the transmission line to a longer distance. Hence Flexible AC Transmission Systems (FACTS) devices such as static compensator (STATCOM) unified power flow controller (UPFC) and static volt–ampere compensator (SVC) are used to alleviate these problems. In this paper, a voltage source converter (VSC) based STATCOM is developed with PI and Artificial Neural Network Controller (ANNC). The conventional PI controller has more tuning difficulties while the system parameter changes, whereas a trained neural network requires less computation time. The ANNC has the ability to generalize and can interpolate in between the training data. The ANNC designed was tested on a 75 V, ±3KVAR STATCOM in real time environment via state-of-the-art of digital signal processor advanced control engineering (dSPACE) DS1104 board and it was found that it was producing better results than the PI controller.     

Scheduling optimisation of flexible manufacturing systems using particle swarm optimisation algorithm

The increased use of flexible manufacturing systems (FMS) to efficiently provide customers with diversified products has created a significant set of operational challenges. Although extensive research has been conducted on design and operational problems of automated manufacturing systems, many problems remain unsolved. In particular, the scheduling task, the control problem during the operation, is of importance owing to the dynamic nature of the FMS such as flexible parts, tools and automated guided vehicle (AGV) routings. The FMS scheduling problem has been tackled by various traditional optimisation techniques. While these methods can give an optimal solution to small-scale problems, they are often inefficient when applied to larger-scale problems. In this work, different scheduling mechanisms are designed to generate optimum scheduling; these include non-traditional approaches such as genetic algorithm (GA), simulated annealing (SA) algorithm, memetic algorithm (MA) and particle swarm algorithm (PSA) by considering multiple objectives, i.e., minimising the idle time of the machine and minimising the total penalty cost for not meeting the deadline concurrently. The memetic algorithm presented here is essentially a genetic algorithm with an element of simulated annealing. The results of the different optimisation algorithms (memetic algorithm, genetic algorithm, simulated annealing, and particle swarm algorithm) are compared and conclusions are presented .     

Sources and impacts of pharmaceutical components in wastewater and its treatment process: A review

Pharmaceutical compounds and their derivatives are major pollutants in the environment, as their metabolites affect the terrestrial as well as aquatic organisms in one or another way. In recent times, many papers have discussed the treatment procedures for single pharmaceutical and mixture of pharmaceutical components, but only few papers have discussed the fate and the exposure of pharmaceutical contaminants in our environment. In this paper, we discuss the sources and the forms of pharmaceutical products and their resultant in the environment and their addition to the microbial and to human communities. A detailed discussion of various treatment techniques from conventional to current techniques, their advantages and disadvantages is given here. Researchers are finding the techniques in order to completely degrade the contaminants and their transformed products from the environment. Among the technique, s nanotechnology was found to be an efficient technique, and the combination of nanotechnology with other conventional technologies gives higher removal efficiency.     

Hydrogen Generation from CO2 Reforming of Biomass-Derived Methanol on Ni/SiO2 Catalyst

Topics in Catalysis - CO2 reforming of methanol for producing hydrogen was experimentally carried out in a fixed-bed reactor on 10%Ni/SiO2. The 10%Ni/SiO2 was completely reduced during H2...     

Structural health monitoring of railway tracks using IoT-based multi-robot system

Neural Computing and Applications - A multi-robot-based fault detection system for railway tracks is proposed to eliminate manual human visual inspection. A hardware prototype is designed to...     

Concurrent optimization of machining process parameters and tolerance allocation

With the advent use of sophisticated and high-cost machines coupled with higher labor costs, concurrent optimization of machining process parameters and tolerance allocation plays a vital role in producing the parts economically. In this paper, an effort is made to concurrently optimize the manufacturing cost of piston and cylinder components by optimizing the operating parameters of the machining processes. Design of experiments (DoE) is adopted to investigate systematically the machining process parameters that influence product quality. In addition, tolerance plays a vital role in assembly of parts in manufacturing industries. For the selected piston and cylinder component, improvements efforts are made to reduce the total manufacturing cost of the components. By making use of central composite rotatable design method, a module of DoE, a mathematical model is developed for predicting the standard deviation of the tolerance achieved by grinding process. This mathematical model, which gives 93.3% accuracy, is used to calculate the quality loss cost. The intent of concurrent optimization problem is to minimize total manufacturing cost and quality loss function. Genetic algorithm is followed for optimizing the parameters. The results prove that there is a considerable reduction in manufacturing cost without violating the required tolerance, cutting force, and power.     

Prediction of the tensile capacity of cold formed angles experiencing shear lag

The present study deals with the shear lag phenomenon in cold formed angles under tension, which are connected on one leg. A new expression for shear lag factor which represents the net section reduction coefficient has been suggested in the present paper. The proposed expression based on the regression analysis of 108 experimental results reported in the literature is validated by experiments involving net section failure in angles under tension. Totally 18 experiments were carried out on single angles fastened with bolts to the gusset plates under tension loaded upto net section rupture mode of failure. The experimental test parameters considered are number of bolts, pitch and shear lag distances and ratio of connected leg length to unconnected leg length. The tensile capacities are evaluated by various specifications such as AS/NZS:4600:2005, NAS:2001, AISC:2005, BS:5950-Part5:1998, IS:800-2007 and the proposed equation. A comparative study of tensile capacities predicted based on various codes and the experiment results is presented in this paper. For the tested range of specimens, both NAS:2001 and AISC:2005 standards over-predicted the capacities for all the specimens. The IS:800-2007 and AS/NZS 4600:2005 predictions are good for the specimens with three bolted connections and unconservative in the case of specimen with two bolts. Both BS:5950-Part-5:1998 and the proposed equation for IS:801 predict good estimate of the tensile capacity of cold formed angle members. The proposed equation for cold formed steel tension members, which is in the same format of IS:800 (2007) (Indian code for Hot rolled steel design), has been demonstrated to be good.     

Inverted emulsion polymerization route to polyaniline‐3D nanofiber network using sulfonated‐p‐cresol as novel dopant

Sulfonated‐p‐cresol (SPC) was used as novel dopant for the first time in the synthesis of polyaniline in 3D nanofiber networks (PANI‐3D). Polyaniline in 3D nanofiber network was prepared using organic solvent soluble benzoyl peroxide as oxidizing agent in presence of SPC and sodium lauryl sulfate (SLS) surfactant via inverted emulsion polymerization pathway. The influence of synthesis conditions such as the concentration of the reactants, stirring/static condition, and temperature etc., on the properties and formation of polyaniline nanofiber network were investigated. Polyaniline in 3D nanofiber network with 40–160 nm (diameter), high yield (134 wt % with respect to aniline used), and reasonably good conductivity (0.1 S/cm) was obtained in 24 h time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011