Application of fuzzy analytic network process for supplier selection in a manufacturing organisation

The contemporary manufacturing organisations are forced to adopt advanced manufacturing paradigms for sustaining in the global markets. Supply chain management is an essential ingredient of advanced manufacturing systems since outsourcing gains vital importance. Supplier selection is a vital issue concerned in the process of managing global supply chains. A conceptual model for supplier selection encompassing various criteria and sub-criteria has been developed. In this article, fuzzy analytic network process (fuzzy ANP) approach has been used for the supplier selection process. The case study has been carried out in an Indian electronics switches manufacturing company. Based on supplier selection weighted index, the best supplier has been determined. This is followed by the conduct of sensitivity analysis as well as questionnaire-based validation. The results of the validation study indicated that the application of fuzzy ANP is practically feasible and adaptable in the contemporary industrial scenario.     

A new weighted‐sum‐of‐gray‐gases model for oxy‐combustion scenarios

A new weighted‐sum‐of‐gray gases (WSGG) model that is based on the statistical narrow band model (SNB) RADCAL is proposed for use in computational fluid dynamic (CFD) simulations of air and oxy‐combustion. When employed in conjunction with the discrete ordinates (DO) method, the model predictions compare well against line‐by‐line benchmark data that have been made available recently that are based on the latest spectroscopic databases. Furthermore, the model compares well against the EM2C SNB model calculations that have served as benchmark data in three‐dimensional geometries. Radiative transfer calculations in these prototypical problems therefore confirm recent experimental observations that SNB RADCAL and EM2C SNB serve as good model databases to develop approximate radiative property models. To achieve an optimum balance of speed and accuracy in computationally intensive CFD simulations, non‐gray formulations of the WSGG model are also employed with the P1 model and solutions are compared against those generated by the DO model. While the P1 model gave favorable comparisons when cold, black walls were present, the errors in the surface incident radiative flux predictions increased in the presence of hot, reflecting walls. Finally, in fully coupled simulations of natural gas combustion under air‐firing and oxy‐firing modes, the predicted incident radiative flux profiles were distinctly different between the gray and non‐gray calculations at regions of high temperature gradients, while the centerline temperature predictions were comparatively unaffected. The effects of turbulence radiation interactions were also accounted for through the temperature self‐correlation term. However, the magnitudes of the temperature fluctuations were small and localized within this furnace and did not significantly alter our predictions. Copyright © 2012 John Wiley & Sons, Ltd.     

A new weighted-sum-of-gray-gases model for CO2–H2O gas mixtures

Decoupled radiative transfer calculations of Sandia Flame D are performed employing experimental measurements of temperature and gas compositions and the discrete ordinates method. Turbulence radiation interactions are accounted for employing temperature variance measurements. The spatial variations in the mean H₂O/CO₂ ratios within the flame are seen to vary widely and sometimes fall outside the range of the weighted-sum-of-gray-gases model (WSGGM) parameters reported in the literature. Therefore, parameters for a new WSGGM are computed from total emissivity correlations encompassing the range of the H₂O/CO₂ ratios encountered within the flame. Predictions from the new model compare favorably against the spectral-line-based WSGGM and existing benchmarks.     

Finite element analysis of contact–impact between a shell of revolution and a rigid wall

In this paper an attempt is made to use a shell theory that includes transverse normal stresses to study the contact–impact behaviour involving thick shells. The problem is solved using the finite element method. The contact criterion is imposed by means of displacement and force constraints. The Lagrangian multipliers technique is used to impose these constraints. The case of a spherical shell impacting a rigid wall with a constant velocity is considered for the analysis. It is shown that the method produces accurate results with less amount of computation than the usual three-dimensional analyses. The effects of the thickness of shell, velocity of impact and modulus of the material are studied.     

Seismic stability of embankments with different densities and upstream conditions related to the water level

Modeling an embankment by subjecting it to different upstream conditions in a centrifuge is challenging. However, the response of an embankment to shaking under different upstream conditions needs to be studied to ensure that the necessary precautions are taken during its construction and maintenance. Herein, the influence of different upstream conditions and embankment densities are investigated. The pore water pressure values at different locations in an embankment were recorded during seepage and under induced shaking. Accelerometers recorded the response of the embankment to shaking, and a linear variable differential transformer (LVDT) measured the settlement at the top of the embankment as a result of the shaking. An image analysis was used to trace the resulting deformation of the embankment due to the shaking. The results indicate that the upstream conditions of the embankment determine the failure mechanism of the embankment in cases of lower density. In addition, the distribution of the water content within the embankment was found to have a greater influence on its response to shaking than the water level height on its upstream side.     

Development of sensitive and specific multiplex PCR method for the detection of microcystin producing cyanobacteria in spirulina food supplements

Food Science and Biotechnology - Spirulina has emerged as the next-generation dietary supplement owing to its health benefits. Despite the advantages, there have been reports of contamination by...     

A systematic method to synthesize all dividing wall columns for n‐component separation—Part I

We present an easy‐to‐use step‐wise procedure to synthesize an initial‐dividing wall column (i‐DWC) from any given n‐component basic distillation column sequence or its thermally coupled derivative. The procedure to be used is dependent on the nature of the distillation column sequence that is to be converted into a DWC, and comprises of an intuitive set of steps that we demonstrate through examples. It is noteworthy that, even for a ternary distillation, 15 potentially useful DWCs, some of which had been missing from the literature, have now been identified. This work significantly expands the search space of useful DWCs to separate any given multicomponent mixture. © 2017 American Institute of Chemical Engineers AIChE J, 64: 649–659, 2018     

Single photon counting from individual nanocrystals in the infrared

Experimental restrictions imposed on the collection and detection of shortwave-infrared photons (SWIR) have impeded single molecule work on a large class of materials whose optical activity lies in the SWIR. Here we report the successful observation of room-temperature single nanocrystal photoluminescence at SWIR wavelengths using a highly efficient multielement superconducting nanowire single photon detector. We confirm that the photoluminescence from single lead sulfide nanocrystals is strongly antibunched, demonstrating the feasibility of performing sophisticated photon correlation experiments on individual weak SWIR emitters, and, more broadly, paving the way for sensitive measurements of spectral observables on infrared quantum systems that are incompatible with current detection techniques.     

Application of fuzzy analytic network process for agile concept selection in a manufacturing organisation

Twenty-first century manufacturing organisations are capable of satisfying the varied requirements of modern customers called agile manufacturing (AM). AM enables an organisation to produce a variety of products within a short period of time in a cost-effective manner. Few researchers have brought out models for enabling organisations to improve their agility level. Total agile design system (TADS) is a model that is analogous to the technology integrated agile product development cycle. Concept selection is an important phase of TADS which is a multi-criteria decision-making (MCDM) problem. Selection of the best concept from agile perspective gains vital importance. Analytical network process (ANP) is a holistic approach that considers interactions and dependencies of various attributes and alternatives in a hierarchical framework used in MCDM problems. The concepts of fuzzy logic have been integrated with ANP in order to overcome the vagueness and uncertainty associated with opinions of the decision makers. Fuzzy ANP has been used to enable the selection of best concept. The case study has been carried out in an Indian traditional manufacturing organisation. The results of the validation indicate that fuzzy ANP is an effective approach for selecting best concept thereby improving agility of product development process.     

Combustion synthesis of alumina with possible CO-GENERATION of power

Aluminum-water combustion method has been advocated to produce hydrogen and synthesize ceramic materials with high purity. In the present study, aluminum-water combustion was employed to synthesize alumina, along with possible co-generation of power. The exhaust gases from aluminum-water combustion comprises of 70% (by mole basis) of hydrogen. This hydrogen gas was burnt with excess air, around an A/F ratio of 16:1 to produce large mass flow rate of gases at temperatures around 1873 K. These gases could be further used to run a turbine for generating power. The possible power generation for this method was estimated to be 6.37 MW per kg of aluminum. The purity and the fraction of alumina in the residue of aluminum-water combustion was mainly influenced by oxidizer to fuel (O/F) ratio. The stoichiometric O/F ratio of 1 resulted in 94% pure α-alumina at all pressures, which was confirmed by X-Ray diffraction (XRD) analysis.