Silver nanoparticle anchored with novel crosslinked beaded polystyrene/polyamidoxime sequential interpenetrating polymer networks (IPNs) and its antibacterial activity

The present article describes the synthesis of silver nanoparticles (SNPs) impregnatated crosslinked beaded polystyrene/polyamidoxime (PSD/PAMD) interpenetrating polymer networks (IPNs). The developed SNPs‐IPNs were tested for the antibacterial activity for water purification. Intially, the crosslinked beaded polystyrene/polyacrylonitrile (PSD/PAN) polymer was synthesized by radical sequential suspension polymerization method therafter, it has been converted into PSD/PAMD‐IPN comprising amidoxime group, which acts as capping agent to anchor the silver ions. The silver ions impregnated with PSD/PAMD‐IPN were converted into SNPs by chemical reduction methodology followed by stabilization without any deterioration or loss in polymer. IR and solid‐state ¹³C NMR spectra were use for the structural characterization of developed SNPs‐IPN, while morphological characterization was examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The size of the SNPs formed with the networks were found less than 5 nm. The disinfection potential of SNPs‐IPN was evaluated by different antibacterial test. The bactericidal test of SNPs‐IPN revealed the promissing antibacterial efficieny with complete microbial inhibition within 4–6 h. The reusability of the SNPs‐IPN beads was also tested for its repeated use for industrial application. POLYM. COMPOS., 70–80, 2016. © 2014 Society of Plastics Engineers     

Sub-critical fouling in a membrane bioreactor for municipal wastewater treatment: experimental investigation and mathematical modelling

Fouling is a major limitation for the application of membrane bioreactors (MBRs) in municipal wastewater treatment; the critical flux concept represents a valid tool for process optimisation in planning fouling control strategies. The paper presents the results obtained on a large pilot MBR equipped with a plate-and-frame ultrafiltration membrane. The experimental assessment of flux criticality was carried out by flux-stepping tests showing the positive impact of liquid temperature on the value of the critical threshold. The reliability of short-term tests was then verified over a long period by determining the time of sustainability, t(sust), of six different sub-critical fluxes ranging between 17 and 30Lm(-2)h(-1). An exponential fitting was observed in terms of fouling rate both before and after t(sust), though fouling after t(sust) is likely to be ascribed not only to cake formation. Finally, a new mathematical formulation was proposed according to the local flux approach to model the sub-critical TMP transients. The model involves both bound and free forms of EPS and, once experimentally calibrated, it provided a fair prediction of the TMP jump.     

Identification of yeast strains isolated from marcha in Sikkim, a microbial starter for amylolytic fermentation

Marcha or murcha is a traditional amylolytic starter used to produce sweet-sour alcoholic drinks, commonly called jaanr in the Himalayan regions of India, Nepal, Bhutan, and Tibet (China). The aim of this study was to examine the microflora of marcha collected from Sikkim in India, focusing on yeast flora and their roles. Twenty yeast strains were isolated from six samples of marcha and identified by genetic and phenotypic methods. They were first classified into four groups (Group I, II, III, and IV) based on physiological features using an API test. Phylogenetic, morphological, and physiological characterization identified the isolates as Saccharomyces bayanus (Group I); Candida glabrata (Group II); Pichia anomala (Group III); and Saccharomycopsis fibuligera, Saccharomycopsis capsularis, and Pichia burtonii (Group IV). Among them, the Group I, II, and III strains produced ethanol. The isolates of Group IV had high amylolytic activity. Because all marcha samples tested contained both starch degraders and ethanol producers, it was hypothesized that all four groups of yeast (Group I, II, III, and IV) contribute to starch-based alcohol fermentation.     

Effects of enzymes in diets with varying energy levels on growth and egg production performance of Japanese quail

The present study was conducted to evaluate the effect of feed‐grade enzyme supplementation in diets with varying levels of energy on the performance of growing and laying Japanese quails. Day‐old Japanese quails, 504 in number, were subjected to six dietary treatments with six replicates at each treatment. Each replicate had 14 chicks. The dietary treatments consisted of three energy levels ie 12.15 MJ (2900 kcal), 11.30 MJ (2700 kcal) and 10.48 MJ (2500 kcal) ME kg^?1 diet and two enzyme levels (0 and 0.5 g kg^?1 diet). A metabolism trial was conducted at the fourth week of age. At the end of week 5, 10 quails (five of each sex) per treatment were sacrificed for carcass characteristics and 20 female quails from each of the six dietary groups were housed in individual laying cages and fed respective layer diet to study the laying performance and egg quality up to 20 weeks of age. Body weight gains of quails fed 12.15 MJ or 11.30 MJ ME kg^?1 diets were significantly higher (p < 0.01) than those fed diets with 10.46 MJ ME kg^?1 diet. Feed intake was significantly lower (p < 0.01) in birds that received diet with 12.15 MJ ME kg^?1 than in birds that diets containing either 11.30 or 10.46 MJ ME kg^?1 diet. Feed conversion ratio (p < 0.01) was best at 12.15, followed by 11.30 and 10.46 MJ ME kg^?1 diet. Enzyme supplementation did not improve the growth performance, feed intake or feed conversion efficiency of quails. Enzyme addition also did not influence nitrogen retention or energy or dry matter metabolizability. The carcass characteristics did not differ because of energy or enzyme supplementation. Feed intake increased significantly (p < 0.01) as the dietary energy level decreased. The egg production and quality characteristics remained almost similar in all the dietary treatments. It was concluded that the optimum dietary energy level for quail was 12.15 MJ (2900 kcal) ME kg^?1 during the growing phase and 11.30 MJ (2700 kcal) ME kg^?1 during the laying phase. Addition of feed enzymes to conventional diets containing varying levels of maize, soyabean meal, fish meal and deoiled rice bran was not beneficial to improve growth, carcass traits, egg production performance or nutrient utilization. Copyright © 2004 Society of Chemical Industry     

Conversion schemes in residue code

In this paper, an implementation scheme involving decoders and residue adders has been suggested to convert input data in fixed radix representation to residue representation. A method dealing with the reverse process is also demonstrated. A comparison has been made with the methods known hitherto.     

Brain tumor detection and segmentation using mesh-free super-diffusive model

Multimedia Tools and Applications - Brain tumor detection and segmentation is a complex and challenging task in image processing. Most of the techniques used for brain tumor detection and...     

Tailor-made pH-sensitive polyacrylic acid functionalized mesoporous silica nanoparticles for efficient and controlled delivery of anti-cancer drug Etoposide

A multifaceted therapeutic platform has been proposed for controlled delivery of Etoposide (ETS) leading to a synergistic advantage of maximum therapeutic efficacy and diminished toxicity. A state of the art pH responsive nanoparticles (NPs) MSNs-PAA consisting of mesoporous silica nanoparticles core and polymeric shell layers, were developed for controlled release of model anti-cancer drug ETS. Graft onto strategy was employed and amination served as an interim step, laying a vital foundation for functionalization of the MSN core with hydrophilic and pH responsive polyacrylic acid (PAA). MCM-41-PAA were investigated as carriers for loading and regulated release of ETS at different pH for the first time. The PAA-MSNs contained 20.19% grafted PAA as exhibited by thermogravimetric analysis (TGA), which enormously improved the solubility of ETS in aqueous media. The synthesized PAA-MSNs were characterized by various techniques viz, SEM-EDS, TEM, BET, FT-IR and powder XRD. ETS was effectively loaded into the channels of PAA-MSN via electrostatic interactions. The cumulative release was much rapid at extracellular tumor (6.8) and endosomal pH (5.5) than that of blood pH (7.4). Hemolysis study was done for the prepared NPs. MTT assay results showed that the drug-loaded ETS-MCM-41-PAA NPs were more cytotoxic to both prostate cancer cells namely PC-3 and LNCaP than free ETS, which was attributed to their slow and sustained release behavior. The above results confirmed that PAA-MSN hold a great potential as pH responsive carriers with promising future in the field of cancer therapy.     

Comparative analysis on the application of neuro‐fuzzy models for complex engineered systems: Case study from a landfill and a boiler

This work aims at developing an explicit neuro‐fuzzy (NF) model to characterize complex engineered systems associated with high nonlinearity, uncertainties, and multivariable couplings. The NF model synergistically exploits the advantages of fuzzy belongingness of each input variable to all output variables and learning ability of neural networks. Owing to the inherent complexities associated with 2 complex engineered systems, a landfill and a boiler were selected to develop models that provide intelligent decisions for optimizing the operational parameters. Data compiled from field‐scale investigation/real plant operation involving various operating scenarios were used to develop the models. Predicting capability of the developed models was evaluated through the correlation coefficient and mean absolute percentage error values. Superiority of the proposed NF model to other similar models has been justified and demonstrated.     

Validation of the MEDFICTS dietary questionnaire: A clinical tool to assess adherence to American Heart Association dietary fat intake guidelines

Background  

Dietary assessment tools are often too long, difficult to quantify, expensive to process, and largely used for research purposes. A rapid and accurate assessment of dietary fat intake is critically important in clinical decision-making regarding dietary advice for coronary risk reduction. We assessed the validity of the MEDFICTS (MF) questionnaire, a brief instrument developed to assess fat intake according to the American Heart Association (AHA) dietary "steps".