An efficient formulation for thin-walled beams curved in plan

An efficient formulation is developed for the elastic analysis of thin-walled beams curved in plan. Using a second-order rotation tensor, the strain values of the deformed configuration are calculated in terms of the displacement values and the initial curvature by adopting the right extensional strain measure. The principle of virtual work is then used to obtain the nonlinear equilibrium equations, based on which a finite element beam formulation is developed. The accuracy of the method is confirmed through comparison with test results, shell finite element formulations and other curved beam formulations from the literature. It is also shown that the results of the developed formulation are very accurate for the cases where initial curvature is large.     

Effects of dietary black cumin seed (Nigella sativa L.) on performance,egg traits,egg cholesterol content and egg yolk fatty acid composition in laying hens

BACKGROUND: The objective of this study was to determine the effects of dietary black cumin seed on performance, egg traits, egg cholesterol content and egg yolk fatty acid composition in laying hens during a 12 week period. For this purpose a total of 160 Lohmann Brown laying hens 36 weeks of age were allocated to four dietary treatments with one control group and three treatment groups. Black cumin seed (Nigella sativa L.) was used at the level of 5, 10 and 15 g kg^?1 in the diets of the first, second and third treatment groups, respectively. RESULTS: Dietary treatments did not significantly affect body weight, feed intake, egg production, egg quality characteristics and blood parameters. Diets containing 10 and 15 g kg^?1 black cumin seed increased egg weight (P < 0.01), improved feed efficiency (P < 0.01) and decreased egg yolk cholesterol, saturated fatty acids (% of total fatty acid methyl esters) and the ratio of saturated to unsaturated fatty acids (P < 0.05) compared to the diet of control group. CONCLUSION: Dietary black cumin seed at the level of 10 and 15 g kg^?1 had beneficial effects on egg weight, feed efficiency, egg cholesterol content and egg yolk fatty acid composition. Therefore it can be used at the level of 10 and 15 g kg^?1 in the diets of laying hens. Copyright © 2009 Society of Chemical Industry     

Energetic and exergetic performance evaluations of a geothermal power plant based integrated system for hydrogen production

In this paper, we propose an integrated system aiming for hydrogen production with by-products using geothermal power as a renewable energy source. In analyzing the system, an extensive thermodynamic model of the proposed system is developed and presented accordingly. In addition, the energetic and exergetic efficiencies and exergy destruction rates for the whole system and its parts are defined. Due to the significance of some parameters, the impacts of varying working conditions are also investigated. The results of the energetic and exergetic analyses of the integrated system show that the energy and exergy efficiencies are 39.46% and 44.27%, respectively. Furthermore, the system performance increases with the increasing geothermal source temperature and reference temperature while it decreases with the increasing pinch point temperature and turbine inlet pressure.     

High performance electrocatalysts supported on graphene based hybrids for polymer electrolyte membrane fuel cells

In this study, new electrocatalysts for PEM fuel cells, based on Pt nanoparticles supported on hybrid carbon support networks comprising reduced graphene oxide (rGO) and carbon black (CB) at varying ratios, were designed and prepared by means of a rapid and efficient microwave-assisted synthesis method. Resultant catalysts were characterized ex-situ for their structure, morphology, electrocatalytic activity. In addition, membrane-electrode assemblies (MEAs) fabricated using resultant electrocatalysts and evaluated in-situ for their fuel cell performance and impedance characteristics. TEM studies showed that Pt nanoparticles were homogeneously decorated on rGO and rGO-CB hybrids while they had bigger size and partially agglomerated distribution on CB. The electrocatalyst, supported on GO-CB hybrid containing 75% GO (HE75), possessed very encouraging results in terms of Pt particle size and dispersion, catalytic activity towards HOR and ORR, and fuel cell performance. The maximum power density of 1090 mW cm^?2 was achieved with MEA (Pt loading of 0.4 mg cm^?2) based on electrocatalyst, HE75. Therefore, the resultant hybrid demonstrated higher Pt utilization with enhanced FC performance output. Our results, revealing excellent attributes of hybrid supported electrocatalysts, can be ascribed to the role of CB preventing rGO sheets from restacking, effectively modifying the array of graphene and providing more available active catalyst sites in the electrocatalyst material.     

Major flavan-3-ol composition and antioxidant activity of seeds from different grape cultivars grown in Turkey

The major flavan-3-ols composition and antioxidant activity of the seeds of 12 different common grape varieties that grow in Turkey were investigated. The quantities of gallic acid, catechin, epicatechin and total flavan-3-ol were determined with high performance liquid chromatography (HPLC) and spectrophotometric method in grape seeds extracts. Gallic acid, catechin, epicatechin and total flavan-3-ol varied from 18 to 101, 121–845, 85–893 and 4 507–13 360 mg/100 g in grape seeds, respectively. The seeds of Papaz Karası, Alicante Boushet and Kalecik Karası cultivars were good sources for these compounds among the cultivars examined. In most cultivars, the amount of epicatechin was greater than that of catechin. The cultivars that have high total flavan-3-ol content had the strongest free radical scavenging activities and results were shown that there is a highly significant correlation between the total flavan-3-ol content and antiradical efficiency (AE) (r=0.9168, P<0001).     

Inhibition of selected pathogens inoculated on the surface of catfish fillets by high molecular weight chitosan coating

Antibacterial activity of high molecular weight water-soluble (HMWWS) chitosan (800 kDa) was investigated against four Gram-negative (Escherichia coli, Salmonella typhimurium, Vibrio cholerae and Vibrio parahaemolyticus) and two Gram-positive (Staphylococcus aureus and Listeria monocytogenes) bacteria. Catfish fillets were surface-inoculated with these food-borne pathogens and coated with chitosan dissolved in aspartic acid (AS) or acetic acid (AC) solution at different concentrations (1% or 3%). Samples were stored at 4 °C for 8 days, except for those inoculated with Vibrio species (10 °C for 6 days). Overall, the most effective coating treatment was the 3% HMWWS chitosan in AS solution (800AS3%). Compared with the control, significant (P < 0.05) reductions caused by 800AS3% were observed for all tested pathogens at the end of storage. The growth of V. parahaemolyticus was completely suppressed by 800AS3%. This study demonstrated that HMWWS chitosan in AS solution could be used as an alternative antimicrobial coating for catfish fillets.     

Combustion performance and kinetics of oil shales

In this research, combustion performance and kinetics of two Turkish oil shales were investigated using differential scanning calorimetry (DSC), thermogravimetry (TGA/DTG), and thermogravimetry–mass spectrophotometry (TG–MS) techniques at three different heating rates (10, 30, and 50°C/min). The combustion reaction occurred in two different regions and the corresponding mass loss of oil shales was calculated. Activation energies of oil shale samples are calculated using three different methods and the results are discussed from the viewpoint of the origin and grade of the samples.     

Fruit juice–alcohol mixture analysis using machine learning and electronic nose

The aim of this study is to analyze the raw data collected from a fruit juice–alcohol mixture (a fruit juice–alcohol mixture and a fruit juice–multiple alcohol mixture) and the Halal authentication of a fruit juice–alcohol mixture with electronic nose. Machine learning techniques such as naïve Bayesian classifier, K‐nearest neighbors (K‐NN), linear discriminant analysis (LDA), decision tree, artificial neural network (ANN), and support vector machine (SVM) were used to classify the feature of these collected raw data. There are three types of classification: the first one is a fruit juice and an alcohol mixture type; the second is a fruit juice and multiple alcohol mixture types, and the third is a Halal authentication of a fruit juice and alcohol mixture. We aimed at making cocktails with more successful results on the first two types of classification in the work. Also, we focused on Halal authentication of fruit juice–alcohol mixture in the third classification. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.