515 research outputs found

    Modelling of Metallurgical Processes Using Chaos Theory and Hybrid Computational Intelligence

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    The main objective of the present work is to develop a framework for modelling and controlling of a real world multi-input and multi-output (MIMO) continuously drifting metallurgical process, which is shown to be a complex system. A small change in the properties of the charge composition may lead to entirely different outcome of the process. The newly emerging paradigm of soft-computing or Hybrid Computational Intelligence Systems approach which is based on neural networks, fuzzy sets, genetic algorithms and chaos theory has been applied to tackle this problem In this framework first a feed-forward neuro-model has been developed based on the data collected from a working Submerged Arc Furnace (SAF). Then the process is analysed for the existence of the chaos with the chaos theory (calculating indices like embedding dimension, Lyapunov exponent etc). After that an effort is made to evolve a fuzzy logic controller for the dynamical process using combination of genetic algorithms and the neural networks based forward model to predict the system’s behaviour or conditions in advance and to further suggest modifications to be made to achieve the desired results

    An overview of Engineering Aspects of Solid State Fermentation

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    Solid substrate cultivation (SSC) or solid state fermentation (SSF) is envisioned as a prominent bio conversion technique to transform natural raw materials into a wide variety of chemical as well as bio-chemical products. This process involves the fermentation of solid substrate medium with microorganism in the absence of free flowing water. Recent developments and concerted focus on SSF enabled it to evolve as a potential bio- technology as an alternative to thetraditional chemical synthesis. SSF is being successfully exploited for food production, fuels, enzymes, antibiotics, animal feeds and also for dye degradation. This paper discusses the various micro and macro level engineering problems associated with SSF and some possible solutions for its full commercial realization

    Phyto-assisted synthesis of Silver nanoparticles using Tinospora cordifolia leaf extract and their antibacterial activity: An ecofriendly approach

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    To meet the increasing demands for commercial nanoparticles new eco-friendly methods of synthesis are being discovered. Plant mediated synthesis of nanoparticles offers single step, easy extracellular synthesis of nanoparticles. We report the synthesis of antibacterial Silver nanoparticles using leaf extract of the medicinal plant, Tinospora cordifolia. The leaf extract was prepared by boiling chopped leaves of Tinospora cordifolia in deionized water for 10 min and filtering the mixture with Whatman filter paper No.1. The filtrate was used as a reducing agent and stabilising agent for AgNO3. On adding 1 mM solution of Silver nitrate to the leaf extract and stirring at 75 °C for 25 min, a change in colour from yellow-brown to brown-black specified the production of Silver nanoparticles. The formation of Silver nanoparticles was monitored by UV-visible spectroscopy and further characterization of the synthesized Silver nanoparticles was done by XRD studies. The antibacterial studies were performed on Gram negative and Gram positive pathogens, Salmonella typhi, Pseudomonas aeruginosa, Enterobacter aerogenes and Staphylococcus aureus, by agar well diffusion method, on Mueller Hinton agar medium. The Silver nanoparticles synthesized from Tinospora cordifolia leaf extract were found to have antimicrobial activity against these Gram negative and Gram positive pathogenic bacteria

    Observation of direct and indirect magnetoelectricity in lead free ferroelectric (Na 0.5Bi 0.5TiO 3)-magnetostrictive (CoFe 2O 4) particulate composite

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    A particulate composite consisting of 65 mol. % Na 0.5Bi 0.5TiO 3 and 35 mol. % CoFe 2O 4 was synthesized, and it's structure, microstructure, ferroelectric, magnetostrictive, magnetic, and direct/indirect magnetoelectric properties were studied. The composite showed different magnetization behaviour under electrically poled and un-poled conditions. The percentage change in magnetization as a result of poling is approximately -15% at 500 Oe magnetic field. Magnetostriction measurements displayed a value of λ 11 = -57 × 10 -6 and piezomagnetic coefficient δλ 11/δH = 0.022 × 10 -6 kOe -1 at 2.2 kOe for the composite. The maximum magnetoelectric output varied from 1350 mV/cm to 2000 mV/cm with change in the electrical poling condition

    2,4,8,10,13-Penta­methyl-6-phenyl-13,14-dihydro-12H-6λ5-dibenzo[d,i][1,3,7,2]dioxaza­phosphecin-6-thione

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    In the title compound, C25H28NO2PS, the cyclo­decene ring exhibits a crown conformation. The two dimethyl­benzene rings which are fused symmetrically on either side of the ten-membered ring, make dihedral angles of 20.2 (1) and 18.0 (1)°. The phenyl ring substituted at P is perpendicular to the heterocyclic ring, making a dihedral angle of 88.4 (1)°. The crystal structure is stabilized by very weak intra­molecular C—H⋯O hydrogen bonding

    Disruption of KEX1 gene reduces the proteolytic degradation of secreted two-chain Insulin glargine in Pichia pastoris

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    Insulin glargine is a slow acting analog of insulin used in diabetes therapy. It is produced by recombinant DNA technology in different hosts namely E. coli and Pichia pastoris. In our previous study, we have described the secretion of fully folded two-chain Insulin glargine into the medium by over-expression of Kex2 protease. The enhanced levels of the Kex2 protease was responsible for the processing of the glargine precursor with in the host. Apart from the two-chain glargine product we observed a small proportion of arginine clipped species. This might be due to the clipping of arginine present at the C-terminus of the B-chain as it is exposed upon Kex2 cleavage. The carboxypeptidase precursor Kex1 is known to be responsible for clipping of C-terminal lysine or arginine of the proteins or peptides. In order to address this issue we created a Kex1 knock out in the host using Cre/loxP mechanism of targeted gene deletion. When two-chain glargine was expressed in the Kex1 knock out host of P. pastoris GS115 the C-terminal clipped species reduced by â¼80. This modification further improved the process by reducing the levels of product related impurities. © 2015 Elsevier Inc. Elsevier Inc. All rights reserved

    Effect of superficial air velocity on solidstate fermentation of palm kernel cake in a lab scale fermenter using locally isolated fungal strain

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    Solid state fermentation (SSF) is emerging as an attractive alternative to submerged fermentation despite the engineering problems such as removal of metabolic heat, transport of oxygen and moisture into the particles and the heterogeneity of the substrate. In the present work, a lab scale fermenter which can be operated as fluidized bed and packed bed was fabricated. Solid state fermentation of palm kernel cake (PKC) using fungal strain TW1 was carried out at three superficial air velocities. PKC particles of mean diameter 855 μm were used and the fluidizing medium was air. Reducing sugar concentration, biomass growth, bed moisture content, substrate pH, and hemicellulose content were measured. The maximum increase in reducing sugar concentration was at 0.17 m/s since an increase in mannose from 14.55 to 18.63 mg mannose/g dry PKC was observed. The hemicellulose content of this fermented PKC was estimated and the result was around 10% in reduction of hemicellulose content in fermented PKC. Further improvement of PKC bioconversion can likely be achieved by selection of a more robust microbe that can withstand the conditions in the fluidized bed during SSF and by creating a system which can maintain the moisture content of PKC during SSF of PKC throughout the packed bed

    Synthesis and characterization of metal oxide promoted alumina catalyst for biofuel production

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    Alumina has been widely used as a support in catalysis process which owing to its extremely thermal and mechanical stability, high surface area, large pore size and pore volume. The aim of this study was to synthesize calcium oxide-supported basic alumina catalysts (CaO/Al2O3) by impregnation method and to characterize the properties of the catalyst based on its surface area and porosity, functional group, surface morphology and particle size. Impregnation method was chosen for the synthesization of catalyst which involved contacting the support with the impregnating solution for a particular period of time, drying the support to remove the imbibed liquid and calcination process. In the preparation of catalyst, catalytic performance of CaO/Al2O3 catalyst was measured at different calcined temperatures (650°C, 750°C and 800°C). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Mercury intrusion porosimetry (MIP), and particle size analyzer (Zetasizer) was used to characterize the catalyst. The highest total specific area and the total porosity of the catalyst was obtained at 750oC. FTIR analysis basically studied on the functional groups present in each catalyst synthesized, while SEM analysis was observed to have pores on its surface. Moreover, CaO/Al2O3 catalysts at 650°C produced the smallest particle size (396.1 mn), while at 750°C produced the largest particle size (712.4 mn). Thus it can be concluded that CaO/Al2O3 catalysts has great potential coimnercialization since CaO has attracted many attentions compared to other alkali earth metal oxides especially on the transesterification reaction

    3-(4-Methoxy­benz­yl)-2-methyl-1-phenyl­sulfonyl-1H-indole

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    There are two crystallographically independent mol­ecules in the asymmetric unit of the title compound, C23H21NO3S. The indole ring system is approximately perpendicular to the sulfonyl phenyl ring in both mol­ecules [dihedral angles = 85.42 (8) and 88.30 (9)°]. C—H⋯O inter­actions between mol­ecules stabilize the crystal structure

    Characterization of different metal oxide promoted alumina catalyst

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    In this study, different metal oxide alumina promoted catalysts were prepared and characterized. All the catalysts (CaO/Al2O3, CuO/Al2O3, FeO/Al2O3, MnO/Al2O3, NiO/Al2O3 and ZnO/Al2O3) were prepared using the incipient wetness impregnation method followed by drying and calcination. The characterization of all six samples of catalysts was done to determine the surface morphology, porosity, functional group, thermal stability, metal content and particle size distribution. Scanning electron microscope (SEM) analysis of samples showed that there were pores on the surface of the alumina. Mercury intrusion porosimetry (MIP) showed that copper oxide alumina promoted (CuO/Al2O3) had the high porosity which is 36.77 m2 /g followed by zinc oxide (ZnO/Al2O3), calcium oxide (CaO/Al2O3) nickel oxide (NiO/Al2O3) manganese oxide (MnO/Al2O3) and ferric oxide alumina promoted (FeO/Al2O3) catalysts. Fourier transform infrared spectroscopy (FTIR) analysis showed the presence of by-product existed in all catalysts. Atomic absorption spectroscopy (AAS) analysis showed the presence of Cu, Fe and Zn in the CuO/Al2O3, FeO/Al2O3 and ZnO/Al2O3, while Ca was absent in CaO/Al2O3. Besides, through thermo-gravimetric analyzer (TGA) and differential thermal analysis (DTA), all the catalysts showed a slight decrease in weight which can be considered as a stable catalyst. The particle size distribution analysis using the Zetasizer showed the particle size mean based on the intensity of CaO/Al2O3, CuO/Al2O3, FeO/Al2O3, MnO/Al2O3, NiO/Al2O3 and ZnO/Al2O3 were 2305 nm, 5560 nm, 5560 nm, 1281 nm, 1281 nm and 3580 nm, respectively
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