Predicting preferences of university students for prepaid vs post paid cell phone service plans

Information and communication technologies have recently become widely used, especially among the younger population. In this study, the factors affecting the preference of undergraduate students for prepaid or postpaid cell phone service plans were analyzed and a multi-layer perceptron type feed forward neural network model was developed to predict the preferences. Using the responses to the questionnaire administered to a group of undergraduate students in Istanbul University, the factors determining the preference for service plan were determined with χ2 test for independence. A classification model based on multi-layer perceptron type neural networks was developed. The classification accuracy of this model was compared to linear regression, LDA, QDA, Naive Bayes and decision tree approaches and shown to be superior.     

Use of Salt Baths in the Temperature Range from 175?��C to 540?��C with Uncertainties of Less than 30?m��C

Calibration of thermometers in the temperature range from ?80 °C to 550 °C requires liquid baths; alcohol, water, silicon oil, salt baths and dry block furnaces. In this study, the use of salt baths outside of their usual range of 250 °C to 540 °C for calibrating thermometers in the range between 175 °C and 250 °C is proposed. The calibration range from 150 °C to 250 °C is usually covered by an oil bath, but utilizing a salt bath saves calibration time and resources, improves stability and homogeneity, allows longer term usage of the liquid, and reduces hazardous chemical vapors evaporated at temperatures above 175 °C. This proposal is based on a study of the uncertainty contributions at varying salt bath temperatures in the range from 175 °C to 540 °C which was carried out in this study. Results achieved and analyzed in this study indicate that the implementation of salt baths in this lower temperature range provides opportunities to calibrate reference and/or working thermometers with an uncertainty below 30 m°C, almost the same as the oil-bath uncertainty in the range of 175 °C to 250 °C. The main components of uncertainty contributed by a salt bath over this temperature range are discussed in this study.     

The Inhibitory Effects of L-Adrenaline on Lactoperoxidase Enzyme Purified from Bovine Milk

L-Adrenaline belongs to a group of compounds known as catecholamines, which play an important role in the regulation of the physiological process in living organisms. In the present study, the inhibitory effect of L-adrenaline on lactoperoxidase was examined. Lactoperoxidase (E.C.1.11.1.7) was purified from bovine milk with three consecutive steps: Amberlite CG-50 resin, CM-Sephadex C-50 ion-exchange, and Sephadex G-100 gel filtration chromatography. Lactoperoxidase was purified with a yield of 42.18%, a specific activity of 30.33 EU/mg proteins, and 20.77 purification fold. Enzyme purity was determined with SDS-PAGE, where a single band was observed. The R_z (A₄₁₂/A₂₈₀) value for lactoperoxidase was 0.9. The effect of L-adrenaline on lactoperoxidase was determined using ABTS as a chromogenic substrate. The half maximal inhibitory concentration (IC₅₀) value and an inhibition constant (K_i) values for L-adrenaline were 34.5 and 2.26 μM, respectively. L-Adrenaline was found to be a non-competitive inhibitor.     

A multi-tube pressure probe calibration method for measurements of mean flow parameters in swirling flows

A simple and sensitive measurement method of multi-tube pressure probes applicable in swirling flow fields is presented in this paper. Determination of flow direction associated with local pitch, , and yaw, ψ, angles, magnitudes of local static and dynamic pressures can be achieved through a calibration method used with 3- and 5-tube versions of a multi-tube pressure probe. The 5-tube probe was tested in a conventional air cyclone where a strong rotational flow prevailed while the 3-tube probe was used in a low swirl flow field in a pipe internally fitted with a helical coiled wire insert. The method is based on the rotational sensitivity of the pressure probe handled through non-dimensional calibration parameters.     

Estimation of optimum design of structural systems via machine learning

Three different structural engineering designs were investigated to determine optimum design variables, and then to estimate design parameters and the main objective function of designs directly, speedily, and effectively. Two different optimization operations were carried out: One used the harmony search (HS) algorithm, combining different ranges of both HS parameters and iteration with population numbers. The other used an estimation application that was done via artificial neural networks (ANN) to find out the estimated values of parameters. To explore the estimation success of ANN models, different test cases were proposed for the three structural designs. Outcomes of the study suggest that ANN estimation for structures is an effective, successful, and speedy tool to forecast and determine the real optimum results for any design model.     

Effect of highlighting intention on intentionality and restitutive justice.

Used 4 moral judgment stories to assess intentionality and restitutive justice in 115 children in nursery school and Grades 1 and 3. A treatment designed to highlight intention improved performance on intentionality for 1st- and 3rd-grade Ss but had no effect on restitutive justice responses at any age. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrochemical impedance study of polyaniline electrocoated porous carbon foam

Electropolymerization of aniline on mesophase pitch based carbon foam has been studied in order to evaluate the influence of conductive polymer coating on the properties of carbon foam. The surface morphology of the coating was determined by scanning electron microscopy (SEM). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical properties of resulting modified carbon foam samples. Polyaniline (PANI) electrocoated-mesophase pitch based carbon foam showed good capacitor behavior in 0.5 M H₂SO₄. Better capacitive behavior is obtained for 100 and 150 mV/s compared to other scan rates, under these faster scan rates thinner films of PANI coatings were combined with more porous structure of carbon foam. Conductivity of the carbon foam was increased from 9.23 to 13.73 S/cm by electrocoating of PANI.