Effect of film thickness and curing temperature on the sensitivity of ZnO:Sb thick-film hydrogen sensor

This paper reports the effect of film thickness and curing temperature on the sensitivity of the screen-printed thick-film ZnO (incorporated with 7 wt%Sb) H₂, CO and CH₄ sensors. The sensitivity of the sensors increases up to 60 μm and decreases for higher film thickness. Increase in the curing temperature of the films, decreases the sensitivity of the sensors because of the increase in the average grain size, as observed by scanning electron microscopy. This revised version was published online in July 2006 with corrections to the Cover Date.     

VOLATILE CONSTITUENTS OF ORANGE WINE OBTAINED FROM MORO ORANGES (CITRUS SINENSIS[L.] OSBECK)

The volatile constituents of blood orange wine were determined. Moro variety (Citrus sinensis[L.] Osbeck) was used for the production of wine. The fermentation was performed spontaneously at 20C. Volatile components were extracted with dichloromethane, and analyzed by gas chromatography‐flame ionization detection (GC/FID) and gas chromatography‐mass spectrometry (GC/MS). A total of 64 volatiles, including higher alcohols (20), esters (13), terpenes (11), acids (7), volatile phenols (6), lactones (2), acetal compounds (2), ketone (1), aldehyde (1) and acetoin (1) were identified in wine. The total amount of volatile compounds was 125.0 mg/L. Higher alcohols and esters were the largest groups and made up more than 86% of the volatiles.     

All-pass filters using a single current conveyor

Current conveyors are unity gain active elements exhibiting high linearity, wide dynamic range and better high frequency performance compared with their voltage mode counterparts. In this study a set of single positive-type second generation current conveyor based all-pass filters is presented and a catalogue of canonical topologies is given with some properties in tabular form. In contrast with single topology presentations, 22 different topologies are presented which exhibit identical transfer functions but differ in the number of passive components, component matching constraints, possibility of gain adjustment and other properties.     

Synthesis, characterization and oxide ionic conductivity of β-type solid solution in bismuth oxide doped with ytterbium oxide binary system

In this study, after doping Yb₂O₃ substance to α -Bi₂O₃ substance in the range of 1% ≤ n ≤ 8% in a series of different mole ratios, heat treatment was performed by applying a cascade temperature rise in the range of 700–790 °C for 48 and 120 h and new phases were obtained in the (Bi₂O₃)_1???x (Yb₂O₃) _x system. After 48 h of heat treatment at 750 °C and 120 h of heat treatment at 790 °C, mixtures containing 1–8% mole Yb₂O₃ formed a tetragonal phase. With the help of XRD, crystal systems and lattice parameters of the solid solutions were obtained and their characterization was carried out. Thermal measurements were made by using a simultaneous DTA/TG system. The total conductivity (σ _T) in the β-Bi₂O₃ doped with Yb₂O₃ system was measured using four-probe d.c. method.     

Adaptive-predictive game-playing programs

Abstract

predictive search (APS) is a new method by which systems can improve their search performance through experience. It is believed that the development of such methods is critical, as currently a tremendous number of computational results are potentially wasted by not integrating search and partial search results into the knowledge of a problem-solving system. In the APS model, pattern formation and associative recall are used to improve or replace search. In this paper, the theory, background, and motivations behind the model are presented and its application to two-player game-playing programs is discussed. In these programs, the system develops a knowledge base of patterns (boolean features) coupled with weights and, using pattern-oriented evaluation, performs only 1-ply search, yet competes respectably with programs that search more. The learning mechanism is a hybrid of machine learning and artificial intelligence techniques that have been successful in other settings. Specific examples and performance results are taken from the domains of Hexapawn, Tic-Tac-Toe, Pente, Othello, and chess.     

EFFECTS OF DIFFERENT MACERATION TIMES AND PECTOLYTIC ENZYME ADDITION ON THE ANTHOCYANIN COMPOSITION OF VITIS VINIFERA CV. KALECIK KARASI WINES

Kalecik karasi is an important red grape cultivar for winemaking in Turkey. The effect of three different maceration times (3, 6 and 12 days) and addition of pectolytic enzyme (2 and 4 g/hL) on the anthocyanin and chemical composition of Kalecik karasi wines were studied. High performance liquid chromatography-mass spectrometry coupled with diode array detection was used for analysis. Fourteen anthocyanin compounds were detected in wines. Major anthocyanins in all wines are malvidin-3-glucoside and its acylated esters. The results showed that increasing maceration time, especially with addition of enzymes, gives significant increases in anthocyanin contents. Moreover, the wines treated with enzymes had higher values in total phenolics, tannins, and color intensity than the control wines.

PRACTICAL APPLICATIONS

Anthocyanins are the most important polyphenols in red grapes and red wines with potential health benefits. Therefore, the first analysis of the anthocyanins contents of wine obtained from important turkish cv. Kalecik karasi using liquid-chromatography-mass spectrometry and the influence of different maceration times and addition of pectolytic enzyme on these important phenolic compounds are of interest for scientific literature, the wine industry as well as for the wine consumer.