Photochromic and hydrophilic self-cleaning nature of MoO3 thin films

Journal of Materials Science: Materials in Electronics - MoO3 thin films were synthesized by thermal evaporation method with thicknesses of 300, 400, and 500 nm on FTO substrate. The...     

Acidic bacterial proteases from Bacillus species as an alternative agent for scouring of cotton fabrics

Protease production by Bacillus licheniformis and Bacillus cerus sources follows similar profiles with marginal differences in activity levels (690, 648?U/mL/min, respectively). Optimum pH values of proteases were closer to the neutral at 60°C. Lower scouring efficiency was observed in proteases produced by B. cerus compared to that of B. licheniformis, in terms of weight loss (4.0 and 3.34%), drop absorbency (1.59 and 3.28?s), extractable impurities (2.03 and 2.82%) and Ruthenium red binding (35 and 43%). Reduction in the tear strength was observed in protease-scoured samples compared to the alkali-scoured samples. FTIR results showed the elimination of nitrogen-containing compounds related to proteins, while the peaks related to wax, pectin were present in the scoured cotton samples.     

Stopping criteria for MAPLS-AW,a hybrid multi-objective evolutionary algorithm

Evolutionary algorithms are widely used to solve multi-objective optimization problems effectively by performing global search over the solution space to find better solutions. Hybrid evolutionary algorithms have been introduced to enhance the quality of solutions obtained. One such hybrid algorithm is memetic algorithm with preferential local search using adaptive weights (MAPLS-AW) (Bhuvana and Aravindan in Soft Comput, doi: 10.1007/s00500-015-1593-9, 2015). MAPLS-AW, a variant of NSGA-II algorithm, recognizes the elite solutions of the population and preferences are given to them for local search during the evolution. This paper proposes a termination scheme derived from the features of MAPLS-AW. The objective of the proposed scheme is to detect convergence of population without compromising quality of solutions generated by MAPLS-AW. The proposed termination scheme consists of five stopping measures, among which two are newly proposed in this paper to predict the convergence of the population. Experimental study has been carried out to analyze the performance of the proposed termination scheme and to compare with existing termination schemes. Several constrained and unconstrained multi-objective benchmark test problems are used for this comparison. Additionally, a real-time application economic emission and load dispatch has also been used to check the performance of the proposed scheme. The results show that the proposed scheme identifies convergence of population much earlier than the existing stopping schemes without compromising the quality of solutions.     

Ontology-based Tamil–English cross-lingual information retrieval system

Cross-lingual information retrieval (CLIR) systems facilitate users to query for information in one language and retrieve relevant documents in another language. In general, CLIR systems translate query in source language to target language and retrieve documents in target language based on the keywords present in the translated query. However, the presence of ambiguity in source and translated queries reduces the performance of the system. Ontology can be used to address this problem. The current approaches to ontology-based CLIR systems use manually constructed multilingual ontology, which is expensive. However, many methods exist to automatically construct ontology for any domain in English but not in other languages like Tamil. We propose a methodology for Tamil–English CLIR system by translating the Tamil query to English and retrieve pages in English to address these issues. Our approach uses a word sense disambiguation module to resolve the ambiguity in Tamil query. An automatically constructed ontology in English is used to address the ambiguity of English query. We have developed a morphological analyser for Tamil language, Tamil–English bilingual dictionary and named entity database to translate a Tamil query to English. The translated query is reformulated using ontology and the reformulated queries are given to a search engine to retrieve English documents from the Internet. We have evaluated our methodology for agriculture domain and the evaluation results show that our approach outperforms other approaches in terms of precision.     

Effect of thermophoresis and Brownian motion on the melting heat transfer of a Jeffrey fluid near a stagnation point towards a stretching surface: Buongiorno's model

This analysis intends to address the coupled effect of phase change heat transfer, thermal radiation, and viscous heating on the MHD flow of an incompressible chemically reactive nanofluid in the vicinity of the stagnation point toward the stretching surface, taking a Jeffrey fluid as the base fluid. Convergent analytical solutions for the nonlinear boundary layer equations are obtained by the successive application of scaling variables and the highly efficacious homotopy analysis method. Error analysis is implemented to endorse the convergence of the solutions. Through parametric examination, influence of various physical parameters occurring in analysis of the profiles of velocity, temperature, and nanoparticle concentration, coefficient of surface drag, rates of mass and heat transfer is explored pictorially. The Deborah number and the melting parameter are found to enhance velocity, and the associated momentum boundary layers are thicker, whereas the magnetic field depreciates the flow rate. Temperature is observed to enhance with the thermophoresis parameter, Prandtl number and Eckert number, whereas a reduction is seen with the thermal radiation parameter and Brownian motion parameter. Nanoparticle concentration is depleted by the chemical reaction parameter, the thermophoresis parameter, and the Lewis number.     

Optimized Fibril Network Morphology by Precise Side‐Chain Engineering to Achieve High‐Performance Bulk‐Heterojunction Organic Solar Cells

A polymer fibril assembly can dictate the morphology framework, in forming a network structure, which is highly advantageous in bulk heterojunction (BHJ) organic solar cells (OSCs). A fundamental understanding of how to manipulate such a fibril assembly and its influence on the BHJ morphology and device performance is crucially important. Here, a series of donor–acceptor polymers, PBT1‐O, PBT1‐S, and PBT1‐C, is used to systematically investigate the relationship between molecular structure, morphology, and photovoltaic performance. The subtle atom change in side chains is found to have profound effect on regulating electronic structure and self‐assembly of conjugated polymers. Compared with PBT1‐O and PBT1‐S, PBT1‐C‐based OSCs show much higher photovoltaic performance with a record fill factor (FF) of 80.5%, due to the formation of optimal interpenetrating network morphology. Such a fibril network strategy is further extended to nonfullerene OSCs using a small‐molecular acceptor, which shows a high efficiency of 12.7% and an FF of 78.5%. The results indicate the formation of well‐defined fibrillar structure is a promising approach to achieving a favorable morphology in BHJ OSCs.     

Comparison of the performance of reduced graphene oxide and multiwalled carbon nanotubes based sulfonated polysulfone membranes for electrolysis application

A series of nanocomposites containing reduced graphene oxide (GO) versus multiwalled carbon nanotubes (MWCNTs) as filler contents anchored with sulfonated polysulfone (SPSF) polymer matrix have been successfully prepared by sol–gel technique with up to 0.5 wt%. The influence of reduced GO compared to MWCNTs to enhance conductivity of nanocomposite SPSF membranes for higher efficient water electrolysis applications has been studied. The nanocomposite membranes were characterized using scanning electron microscopy, atomic force microscopy, Raman spectroscopy, transmission electron microscopy, optical microscopy, electrical conductivity, and tensile testing. The membrane porous structure, porosity, and pores uniformity plus the uniformity of dispersion of mixture are investigated. The conductivity of the composite membranes for water electrolysis applications has been characterized using localized probes across the surface. The results show SPSF–GO nanocomposite membranes offer higher conductivity and improved performance than those of SPSF–MCNT. A uniform constant and high current density of 1.39 A/cm² has been achieved in SPSF–GO membrane at 60°C. POLYM. COMPOS. 36:475–481, 2015. © 2014 Society of Plastics Engineers