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Metallurgical and Materials Transactions B - In this work, the mechanical properties of the Al-Cu-Ni eutectic alloy, Al-32.5 wt pct Cu-1 wt pct Ni, were investigated in terms of... 相似文献
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Neural Computing and Applications - In this study, two-channel surface electromyography (sEMG) signals were used to classify hand finger movements. Bicoherence analysis of the sEMG signal recorded... 相似文献
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Ümit Bayram Alaaddin Özer Sezen Aksöz Necmettin Maraşlι 《Metallurgical and Materials Transactions A》2013,44(9):4042-4050
The grain boundary groove shapes for solid neopentylglycol solution (NPG-40 mol pct AMPD) in equilibrium with the neopentylglycol (NPG)–aminomethylpropanediol (AMPD) eutectic liquid (NPG-42.2 mol pct AMPD) have been directly observed using a horizontal linear temperature gradient apparatus. From the observed grain boundary groove shapes, the Gibbs–Thomson coefficient (Г) and solid–liquid interfacial energy (σ SL) of solid NPG solution have been determined to be (7.4 ± 0.7) × 10?8 K m and (6.4 ± 1.0) × 10?3 J m?2, respectively. The grain boundary energy of solid NPG solution has been determined to be (12.5 ± 1.0) × 10?3 J m?2 from the observed grain boundary groove shapes. The ratio of thermal conductivity of equilibrated eutectic liquid to thermal conductivity of solid NPG solution has also been determined to be 0.48. 相似文献
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This study was carried out on very steep and difficult terrain. Whole trees were logged uphill to the forest road by a Koller K300 cable crane. Investigations were carried out by time studies for which the repetition time measurement method was selected. Through time studies, the productivity and cost of the Koller cable system were evaluated. 相似文献
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Ümit Bayram Esra Öztürk Sezen Aksöz Necmettin Maraşlı 《Metallurgical and Materials Transactions A》2013,44(9):4051-4058
Thermal conductivity variations with temperature for solid phases in the Urea (U)–[X] mol pct 4-bromo-2-nitroaniline (BNA) system (X = 0, 2, 45, 89.9, and 100) were measured using the radial heat flow method. From graphs of thermal conductivity variations with temperature, the thermal conductivities of the solid phases at their melting temperature and temperature coefficients for the U–[X] mol pct BNA system (X = 0, 2, 45, 89.9, and 100) were found to be 0.26, 0.55, 0.46, 0.38, and 0.23 W/Km and 0.007781, 0.005552, 0.002058, 0.002188, and 0.002811 K?1, respectively. The ratios of thermal conductivity of the liquid phase to thermal conductivity of the solid phase in the U–[X] mol pct BNA system (X = 0, 2, 45, 89.9, and 100) were also measured to be 0.30, 0.44, 0.46, 0.49, and 0.51, respectively, with a Bridgman-type directional solidification apparatus at their melting temperature. 相似文献
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Leyla Nur Akay Cevriye Kalkandelen Necmettin Akti Merve Sazimet Sengul Cumali Tav Ugur Yahsi Ziya Engin Erkmen 《Journal of the American Ceramic Society》2023,106(5):3220-3227
In this study, the nanostructural vacancy behavior of bovine derived hydroxyapatite (BHA) doped with powder zirconmullite (ZM) contents of 5, 7.5, 10 and 12.5 wt.% were presented at sintering temperatures of 1000, 1100, 1200 and 1300°C. ZM-doped BHA (ZM-BHA) was characterized by X-ray diffraction and positron annihilation lifetime spectroscopy (PALS). Density and hardness behavior were measured with respect to increasing sintering temperature. PALS results indicate that the longest lifetime component τ3 of ortho-positronium (o-Ps) localized at open spaces is attributed to the vacancy site and almost constant with the ZM contents and the sintering temperatures to have a mean value of 0.680 ns (corresponding to the radius of 0.997 nm). This average value is ascribed to the OH group defects along the main crystalline line. On the other hand, the o-Ps intensity attributed to the number of vacancy sites increases almost linearly with ZM additives and sintering temperatures. The intensity is also related to the density and hardness of ZM-BHA in terms of ZM contents. 相似文献
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This paper deals with the current magnesite concentration technology and upgrading studies in Turkey, which is the second biggest magnesite and third biggest sinter magnesia producer in the world. Magnesite heat treatment and magnetic separation fundamentals are also covered. This study aims to concentrate magnesite middlings containing the silica/iron impurities from Kütahya, Turkey, by calcination and dry magnetic separation. Final calcined MgCO3 product contains 89.57% MgO, 0.96% SiO2, 0.43% Fe2O3, 2.35% CaO and 6.64% loss of ignition. The optimum particle size was determined at ?8 + 0.5 mm at 1000°C. Final product is saleable for industrial applications (i.e., soil decontamination, panels, fertilizers, animal nutrition, abrasives). 相似文献
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Mehmet Akin Muhammed B. Kurt Necmettin Sezgin Muhittin Bayram 《Neural computing & applications》2008,17(3):227-236
We developed a new method for estimation of vigilance level by using both EEG and EMG signals recorded during transition from
wakefulness to sleep. Previous studies used only EEG signals for estimating the vigilance levels. In this study, it was aimed
to estimate vigilance level by using both EEG and EMG signals for increasing the accuracy of the estimation rate. In our work,
EEG and EMG signals were obtained from 30 subjects. In data preparation stage, EEG signals were separated to its subbands
using wavelet transform for efficient discrimination, and chin EMG was used to verify and eliminate the movement artifacts.
The changes in EEG and EMG were diagnosed while transition from wakefulness to sleep by using developed artificial neural
network (ANN). Training and testing data sets consist of the subbanded components of EEG and power density of EMG signals
were applied to the ANN for training and testing the system which gives three situations for the vigilance level of the subject:
awake, drowsy, and sleep. The accuracy of estimation was about 98–99% while the accuracy of the previous study, which uses
only EEG, was 95–96%. 相似文献
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Devrim Atilla Necmettin Kilinç Fatma Yuksel Ayşe Gül Gürek Zafer Ziya Öztürk Vefa Ahsen 《Synthetic Metals》2009,159(1-2):13-21
The synthesis of new lutetium(III) bisphthalocyanines substituted with alkylthio groups (1–5) is described. These compounds (Pc2Lu) are soluble in most common organic solvents and have been fully characterized (elemental analysis, FT-IR, UV–Vis spectroscopy, mass spectrometry). The thermal stabilities of the Pc compounds were determined by thermogravimetric analysis (TGA). The mesogenic properties of these new materials forming columnar-hexagonal (Colh) mesophases were studied by differential scanning calorimetry (DSC), optical microscopy and X-ray diffraction. The compounds 2–5 exhibit a double clearing point. DC electrical properties of these compounds in different phases were determined by measuring I–V characteristics and dark current of their thin films on interdigital electrodes. The measurements were carried out in ambient air, in vacuum and in high purity nitrogen (N2) flow in the temperature range between 300 and 420 K. Dark current measurements obtained in the crystal, liquid crystal (LC) and isotropic liquid phases were in agreement with the phase transitions of these compounds obtained by DSC and optical microscopy results. The relation between the phase transition and conductivity of the Pc2Lu derivatives were investigated. Also, the influence of the nature of the substituted group (alkylthia and alkoxy) upon the DC electrical properties of the Pc2Lu derivatives was investigated. The DC conductivities and the thermal activation energies depending on alkyl chain lengths of these compounds were found to be in the range of 10?8 to 10?5 S/cm and 0.12–0.38 eV in solid phase. 相似文献