Computer-aided design of the effects of Fe2O3 nanoparticles on split tensile strength and water permeability of high strength concrete

In the present paper, two models based on artificial neural networks and genetic programming for predicting split tensile strength and percentage of water absorption of concretes containing Fe₂O₃ nanoparticles have been developed. To build these models, training and testing of the network by using experimental results from 144 specimens produced with 16 different mixture proportions were conducted. The data used in the multilayer feed forward neural networks models and input variables of genetic programming models have been arranged in a format of eight input parameters that cover the cement content, nanoparticle content, aggregate type, water content, the amount of superplasticizer, the type of curing medium, age of curing and number of testing try. According to these input parameters, in the two models, the split tensile strength and percentage of water absorption values of concretes containing Fe₂O₃ nanoparticles were predicted. The training and testing results in the neural network and genetic programming models have shown that every two models are of strong potential for predicting the split tensile strength and percentage of water absorption values of concretes containing Fe₂O₃ nanoparticles. Although neural network has predicted better results, genetic programming is able to predict reasonable values with a simpler method rather than neural network.     

A novel chaotic steganography method with three approaches for color and grayscale images based on FIS and DCT with flexible capacity

Multimedia Tools and Applications - In this paper, a new chaotic steganography method based on Fuzzy Inference System (FIS), using Discrete Cosine Transform (DCT) on color and grayscale images is...     

Optimization of Enzymatic Hydrolysis of Visceral Waste Proteins of Yellowfin Tuna (Thunnus albacares)

Fish protein hydrolysate was produced from the viscera of yellowfin tuna (Thunnus albacares). Hydrolysis conditions (enzyme activity, temperature, and time) were optimized using response surface methodology. A factorial design was applied to minimize enzyme utilization and modeling of degree of hydrolysis (r ² = 0.94). Lack-of-fit test revealed a non-significant value for the model, indicating that the regression equation was adequate for predicting the degree of hydrolysis under any combination of the variables (P < 0.05). The optimum conditions to reach the highest degree of hydrolysis were: 60.4 °C, 90.25 min, and a protease (Alcalase 2.4 L) activity of 70.22 AU/kg protein. The spray-dried tuna visceral protein hydrolysates had relatively high protein (72.34%) and low lipid (1.43%) content. The chemical score of the hydrolysate indicated that it fulfils adult human nutritional requirements except for methionine. Lysine and methionine were the first and the second limiting amino acids in that order. Phenylalanine was the predominant amino acid in the hydrolysates with respect to common carp requirement. In addition, the protein efficiency ratio of tuna visceral hydrolysate was 2.85–5.35.     

Polyester with durable UV protection properties through using nano TiO2 and polysiloxane softener optimized by RSM

In this paper, durable ultraviolet (UV) protection properties were obtained on polyester fabric by the treatment with nano titanium dioxide (NTO_P) as UV absorber and polysiloxane (PS) as stabilizer. The cross-linkable PS softener was applied to enhance NTO_P durability creating soft handle. The UV protection (UP) properties of the samples were monitored by evaluating the color differences (ΔE ^?) on the stained methylene blue mounted under the treated samples during the UV irradiation. The response surface methodology was used to design the experiments and also central composite design was utilized for different variables based on Design of Expert software. Diverse UV irradiations were used including daylight for 24?h, UV-A (400?W) for 2?h, and UV-C (20?W) for 6?h. The appropriate model was utilized for each condition to create optimum polyester with UP properties. The results demonstrated that treated sample with 1.42% NTO_P and 3.61% PS had the lowest ΔE ^??=?0.13. Also, transmission spectra analyses (200–800?nm) of the treated polyester samples were in complete agreement and consequently desirable properties of UP were reported. The X-ray diffraction analyses of NTO_P and treated samples indicated the presence of anatase crystal structure in NTO_P which significantly absorbed irradiation with wavelengths of lower than 400?nm and inhibited significant discoloration of methylene blue.     

Influence of the in vivo addition of alpha-tocopheryl acetate with three lipid sources on the lipid oxidation and fatty acid composition of Beluga sturgeon, Huso huso, during frozen storage

This study was conducted to investigate the effect of dietary alpha-tocopheryl acetate (vitamin E) and oil sources on fish flesh quality characteristics of Huso huso during frozen storage. Practical-type diets containing 0 or 250 mg vitamin E kg⁻¹ with three lipid sources, fish oil (FO), soybean oil (SO) and canola oil (CO), were fed to H. huso for 120 days. Fillet samples were analysed fresh or after storage at −18 ± 1 °C for 12 months. Replacement of FO by SO and CO in diets for H. huso significantly altered the fatty acid (FA) profile, which also influenced the FA composition during frozen storage. Dietary vitamin E had a significant effect on muscle vitamin E content and lipid oxidation during storage (P > 0.05). Oxidation was reduced for fish fed vitamin E and results showed that dietary vitamin E supplementation can slow down the level of lipid oxidation in H. huso muscles during frozen storage.     

The combination effects of trivalent gold ions and gold nanoparticles with different antibiotics against resistant Pseudomonas aeruginosa

Despite much success in drug design and development, Pseudomonas aeruginosa is still considered as one of the most problematic bacteria due to its ability to develop mutational resistance against a variety of antibiotics. In search for new strategies to enhance antibacterial activity of antibiotics, in this work, the combination effect of gold materials including trivalent gold ions (Au³⁺) and gold nanoparticles (Au NPs) with 14 different antibiotics was investigated against the clinical isolates of P. aeruginosa, Staphylococcus aureus and Escherichia coli. Disk diffusion assay was carried out, and test strains were treated with the sub-inhibitory contents of gold nanomaterial. Results showed that Au NPs did not increase the antibacterial effect of antibiotics at tested concentration (40 μg/disc). However, the susceptibility of resistant P. aeruginosa increased in the presence of Au³⁺ and methicillin, erythromycin, vancomycin, penicillin G, clindamycin and nalidixic acid, up to 147 %. As an individual experiment, the same group of antibiotics was tested for their activity against clinical isolates of S. aureus, E. coli and a different resistant strain of P. aeruginosa in the presence of sub-inhibitory contents of Au³⁺, where Au³⁺ increased the susceptibility of test strains to methicillin, erythromycin, vancomycin, penicillin G, clindamycin and nalidixic acid. Our finding suggested that using the combination of sub-inhibitory concentrations of Au³⁺ and methicillin, erythromycin, nalidixic acid or vancomycin may be a promising new strategy for the treatment of highly resistant P. aeruginosa infections.     

Synthesis and characterization of poly(catechol) catalyzed by porphyrin and enzyme

Catalytic polymerization of catechol was performed employing the cationic porphyrin and horseradish peroxidase (HRP) as catalysts. The obtained results demonstrate that the cationic metalloporphyrin is a more-efficient catalyst than the HRP in the catechol polymerization. The oxidative polymerization was carried out in the presence of polystyrene sulfonate (PSS) as a template. According to TGA data, poly(catechol) that is synthesized by porphyrin catalyst exhibits more thermal stability than the enzymatic catalyzed product. The GPC indicate higher molecular weight of polymer synthesized by porphyrin as a catalyst. Cyclic voltammetry measurements show that the synthesized polymers have convenient electroactivity. The poly(catechol) and its methyl and methoxy derivatives that are synthesized by porphyrin catalyst show low electrical conductivity.