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.     

World oil prices and agricultural commodity prices: Evidence from an emerging market

Oil prices are thought to have direct effect on agricultural prices followed by an indirect effect through the exchange rate. This paper examines the short- and long-run interdependence between world oil prices, lira-dollar exchange rate, and individual agricultural commodity prices (wheat, maize, cotton, soybeans, and sunflower) in Turkey. To this end, the Toda-Yamamoto causality approach and generalized impulse-response analysis for identification of the long- and short-run interrelationships are applied to the monthly data spanning from January 1994 to March 2010. The impulse-response analysis suggests the Turkish agricultural prices do not significantly react to oil price and exchange rate shocks in the short-run. The long-run causality analysis reveals that the changes in oil prices and appreciation/depreciation of the Turkish lira are not transmitted to agricultural commodity prices in Turkey. Hence, our results support neutrality of agricultural commodity markets in Turkey to both direct and indirect effects of oil price changes.     

Mechanical behavior of the membrane during the polymer electrolyte fuel cell operation

A computational modeling framework is developed to represent the transport phenomena, electrochemistry and the mechanical stresses in a polymer electrolyte fuel cell (PEFC). The model is able to predict the mechanical stresses developed in the polymer electrolyte due to hydration changes, and restriction of the membrane swelling as a result of these hydration changes in the PEFC assembly. Anisotropy in the mechanical properties of the gas diffusion layers is accounted in the stress calculations. It is seen that hydration variations during the PEFC operation can cause significant mechanical stresses. The effects of operating voltage and relative humidities of reactants are investigated. It is observed that high inlet humidities result in a better performance; however, it can potentially cause the polymer electrolyte membrane to go through plastic deformation irreversibly. Thermal stresses due to temperature variations are also calculated and compared with hygral stresses; and it is found that thermal stresses are not negligible but are typically a fraction of the hygral stresses in a typical PEFC operation.     

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.