Decision making in equipment selection: an integrated approach with digraph and matrix approach, AHP and ANP

The equipment selection process is considered in the early stage of the design process since the equipment selection process decides the quality, cost, and reliability, which are important for customer satisfaction. Due to the availability of large numbers of equipment, the selection of suitable equipment for certain operation/product becomes much difficult. The selection process is not so easy a task because the equipment features are many and vary from one manufacturer to another, and the features are also being increased constantly. Since the quality, cost, and reliability of a product are decided by proper equipment selection, the equipment selection process becomes more and more important. This paper describes three multi-attributes decision-making methods, namely, digraph and matrix approach, analytical hierarchical process (AHP), and analytical network process (ANP). These methods provide selection indices for different alternatives considered. In this paper, the selection of milling machine is considered. The problem is solved by digraph and matrix approach, AHP, and ANP methods. The results obtained by the three methods are compared and analyzed. Finally, a milling machine is selected as the best one concerning manufacturing environment.     

Evaluation of photovoltaic efficiency of dye‐sensitized solar cells fabricated with electrospun PVDF‐PAN‐Fe2O3 composite membrane

Poly(vinylidene fluoride)‐polyacrylonitrile‐based membranes containing Fe₂O₃ nanoparticles were prepared by electrospinning technique and characterized by HR‐SEM, FTIR, and XRD analysis. The effect of electrolyte in the electrospun nanofibers on electrolyte uptake, ionic conductivity and porosity were studied. The electrospun membranes containing Fe₂O₃ showed an enhanced ionic conductivity than that of without Fe₂O₃. Among the prepared membranes, the membrane with 7 wt % Fe₂O₃ has the highest liquid electrolyte uptake of 562% and ionic conductivity of 6.81 × 10^?2 S cm^?1. The photovoltaic performance for open circuit voltage (V_oc), Short‐circuit current density (J_sc), Fill factor (FF), and η of the DSSC fabricated with 7 wt % Fe₂O₃ are 0.77 V, 10.4 mA/cm², 0.62 and 4.9%, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41107.     

Development of quasi‐solid‐state dye‐sensitized solar cell based on an electrospun polyvinylidene fluoride–polyacrylonitrile membrane electrolyte

Dye sensitized solar cell (DSSC) has been magnetizing more awareness in current research due to more efficiency. The foremost drawback of the solar cell is the evaporation of organic electrolyte. In order to address this problem, the polyvinylidene fluoride–polyacrylonitrile–Electrospinning Fibrous Membranes were prepared by electrospinning method and the photovoltaic performances were evaluated. The polyvinylidene fluoride and polyacrylonitrile were mixed in N,N′‐dimethylformamide and acetone at an applied potential of 15 kV. The surface morphology of membrane is interconnected with network structure and a large number of voids were observed from Field Emission Scanning Electron Microscopy images. The electrolyte uptakes up to 310% were observed and it shows an increase in the ionic conductivity up to 6.12 × 10^?2 S cm^?1 at 25°C. The fabricated DSSCs show open circuit voltage (V_oc) of 0.74 V, fill factor (FF) of 0.65 and short circuit current (J_sc) of 6.20 mA cm^?2 at an incident light intensity of 100 mW cm^?2. The photovoltaic efficiency also reached up to 3.09%. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40022.     

Selective edge enhancement using anisotropic vortex filter

In optical image processing, selective edge enhancement is important when it is preferable to emphasize some edges of an object more than others. We propose a new method for selective edge enhancement of amplitude objects using the anisotropic vortex phase mask by introducing anisotropy in a conventional vortex mask with the help of the sine function. The anisotropy is capable of edge enhancement in the selective region and in the required direction by changing the power and offset angle, respectively, of the sine function.     

Tailored complex 3D vortex lattice structures by perturbed multiples of three-plane waves

As three-plane waves are the minimum number required for the formation of vortex-embedded lattice structures by plane wave interference, we present our experimental investigation on the formation of complex 3D photonic vortex lattice structures by a designed superposition of multiples of phase-engineered three-plane waves. The unfolding of the generated complex photonic lattice structures with higher order helical phase is realized by perturbing the superposition of a relatively phase-encoded, axially equidistant multiple of three noncoplanar plane waves. Through a programmable spatial light modulator assisted single step fabrication approach, the unfolded 3D vortex lattice structures are experimentally realized, well matched to our computer simulations. The formation of higher order intertwined helices embedded in these 3D spiraling vortex lattice structures by the superposition of the multiples of phase-engineered three-plane waves interference is also studied.     

Optimisation of preparation conditions for Ti nanowires and suitability as an antibacterial material

Ultrafine titanium dioxide (TiO₂) nanowires were synthesised using a hydrothermal method with different volumes of ethylene glycol (EG) and annealing temperatures. It shows that sodium titanate nanowires synthesised using 5 and 10 ml EG, which annealed at 400°C produced TiO₂ nanowires that correspond to a photochemically active phase, which is anatase. The influences of annealing temperatures (400–600°C) on the morphological arrangement of TiO₂ nanowires were evident in the field emission scanning electron microscopy. The annealing temperature of 500°C led to agglomeration, which formed a mixture of TiO₂ nanoparticles and nanowires. High thermal stability of TiO₂ nanowires revealed by thermogravimetric analysis and Fourier transform infrared spectroscopy spectrum showed the presence of the Ti–O–Ti vibrations as evidenced due to TiO₂ lattices. An antibacterial study using TiO₂ nanowires toward Escherichia coli and Klebsiella pneumoniae showed large zones of inhibition that indicated susceptibility of the microbe toward TiO₂. Growth kinetic analysis shows that addition of TiO₂ has reduced optical density (OD) suggesting an inhibition of the growth of bacteria. These results indicate TiO₂ nanowires can be effectively used as an antimicrobial agent against gram‐bacteria. The TiO₂ nanowires could be exploited in the medical, packaging and detergent formulation industries and wastewater treatment.Inspec keywords: nanowires, titanium compounds, antibacterial activity, nanomedicine, semiconductor materials, semiconductor growth, nanofabrication, annealing, liquid phase deposition, field emission scanning electron microscopy, nanoparticles, thermal stability, thermal analysis, Fourier transform infrared spectra, microorganismsOther keywords: optimisation, preparation conditions, antibacterial material, ultrafine titanium dioxide nanowires, hydrothermal method, ethylene glycol, annealing temperatures, sodium titanate nanowires, photochemically active phase, anatase, morphological arrangement, field emission scanning electron microscopy, agglomeration, nanoparticles, thermal stability, thermogravimetric analysis, Fourier transform infrared spectroscopy, vibrations, Escherichia coli, Klebsiella pneumoniae, microbe, growth kinetic analysis, optical density, incubation time, bacterial survivability, colony‐forming units, antimicrobial agent, Gram negative bacteria, Gram positive bacteria, temperature 400 degC to 600 degC, TiO₂      

Strengthening of RC wall-like columns with FRP under sustained loading

In recent years, increasing research efforts have been geared towards studying the repair and strengthening of concrete structures using fibre reinforced polymer (FRP) composites. Numerous studies have shown that structural members such as circular columns can experience a significant increase in strength and ductility due to passive confinement provided by the composite wraps. In rectangular columns, however, limited strength increases have been achieved due to the nonuniform distribution of confining stress around the column. Despite the large number of studies on FRP-confined concrete columns, studies on the strengthening of RC wall-like (i.e. high aspect ratio) columns have been limited. Furthermore, most studies did not consider the effect of sustained loading on the column during repair/strengthening. This paper reports the results of an experimental investigation where various schemes have been used to strengthen wall-like RC columns with and without sustained loading. The effects of sustained loading on the strengthening efficiency as well as the lateral strain distribution in the composite wrap have also been investigated.

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Résumé De nombreux travaux ont été développés ces dernières années dans le but de renforcer et réparer les structures en béton armé utilisant des feuilles de polymère renforcées de fibres de carbone ou de verre (FRP). Plusieurs études ont montré que les colonnes circulaires ont subi une augmentation appréciable de la capacité ultime et la ductilité en raison du confinement passif engendré par les feuilles composites. Cependant, dans les colonnes rectangulaires, l'augmentation de la capacité ultime des membres a été limitée à cause de la distribution non uniforme de la contrainte du confinement autour de la colonne. Malgré les nombreuses études sur les colonnes en béton armé utilisant des FRP, les essais sur les colonnes rectangulaires sont limités. En outre, la plupart des études faites n'ont pas pris en considération l'effet de la charge soutenue par la colonne pendant la réparation ou le renforcement. Cet article rapporte les résultats d'une étude expérimentale où plusieurs méthodes ont été utilisées pour renforcer des colonnes en béton armé à section rectangulaire avec et sans chargement soutenu. Les effets de la charge soutenue sur l'efficacité de renforcement ainsi que les distributions des tensions latérales dans les feuilles composites ont aussi été étudiés.

     

Analysis and design of FRP externally-reinforced concrete beams against debonding-type failures

Epoxy-bonding of FRP plates to the tensile face of RC beams has been shown to be an effective repair and strengthening technique. However, local failure by debonding or ripping of concrete cover has been reported in experiments to be a likely mode of failure due to high interfacial shear and normal stress concentrations. Predictive models for finding the interfacial shear stress have been reviewed and evaluated using experimental data reported in the literature. The most critical parameters governing the interfacial shear strength and stress as determined by the models were also examined. Through understanding of the conditions that result in debonding failure, a better approach towards designing FRP-plated RC beams against this mode of failure might be achieved.

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Résumé Le renforcement externe d'éléments en béton armé à l'aide de plaques synthétiques renforcées de fibres (FRP), s'est révélé être une technique efficace de réhabilitation des structures. Cependant, la rupture locale par décollement ou fissure du béton a été présentée dans des essais comme le mode de rupture le plus fréquent à cause de la forte concentration des contraintes de cisaillement et normales aux extrémités des plaques. Des modèles théoriques visant à trouver les contraintes de cisaillement ont été examinés et évalués en utilisant des données expérimentales rapportées dans la littérature. Les paramètres les plus critiques gouvernant la contrainte de cisaillement et la résistance au cisaillement de l'interface colle-béton, comme déterminé par les modèles théoriques, ont aussi été examinés. Pour comprendre les effets qui résultent de la rupture par décollement, une meilleure méthode de conception peut être réalisée afin d'éliminer ou de retarder ce mode de rupture.

     

A fuzzy logic based supervisory hierarchical control scheme for real time pressure control

This paper describes a supervisory hierarchical fuzzy controller （SHFC） for regulating pressure in a real-time pilot pressure control system. The input scaling factor tuning of a direct expert controller is made using the error and process input parameters in a closed loop system in order to obtain better controller performance for set-point change and load disturbances. This on-line tuning method reduces operator involvement and enhances the controller performance to a wide operating range. The hierarchical control scheme consists of an intelligent upper level supervisory fuzzy controller and a lower level direct fuzzy controller. The upper level controller provides a mechanism to the main goal of the system and the lower level controller delivers the solutions to a particular situation. The control algorithm for the proposed scheme has been developed and tested using an ARM7 microcontroller-based embedded target board for a nonlinear pressure process having dead time. To demonstrate the effectiveness, the results of the proposed hierarchical controller, fuzzy controller and conventional proportional-integral （PI） controller are analyzed. The results prove that the SHFC performance is better in terms of stability and robustness than the conventional control methods.     

Influence of medium on the nanostructure and properties of poly(4‐aminodiphenylamine)‐silver nanocomposites

Poly(4‐aminodiphenylamine)‐silver nanocomposites were synthesized by an easy one‐step aqueous chemical oxidative polymerization of 4‐aminodiphenylamine (4ADPA) using silver nitrate (AgNO₃) as the oxidant. Two different structure directing surfactants, p‐toluene sulfonic acid (p‐TSA) and cetyl trimethyl ammonium bromide/hydrochloric acid (CTAB/HCl), were independently used for the nanocomposite (NC) preparation. The NCs prepared in p‐TSA and CTAB/HCl medium were designated as P4ADPA/AgNC_(p?TSA) and P4ADPA/AgNC_(CTAB/HCl), respectively. We investigated the morphological variations in the NCs based on the medium. P4ADPA/AgNC_(p?TSA) and P4ADPA/AgNC_(CTAB/HCl) were characterized by field emission scanning electron microscopy, X‐ray diffraction analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis and UV‐visible spectroscopy. Copyright © 2011 Society of Chemical Industry