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91.
Nguyen Thu Ha Nguyen Huu Du Do Duc Thuan 《Mathematics of Control, Signals, and Systems (MCSS)》2016,28(2):13
We shall deal with some problems concerning the stability domains, the spectrum of matrix pairs, the exponential stability and its robustness measure for linear implicit dynamic equations of arbitrary index. First, some characterizations of the stability domains corresponding to a convergent sequence of time scales are derived. Then, we investigate how the spectrum of matrix pairs, the exponential stability and the stability radii for implicit dynamic equations depend on the equation data when the structured perturbations act on both the coefficient of derivative and the right-hand side. 相似文献
92.
Myoung Do Seo Young Jo Kim Jong Sung Lim Jeong Won Kang 《Korean Journal of Chemical Engineering》2012,29(1):103-110
Vapor-liquid equilibrium (VLE) for binary mixtures composed of ethanol+methyl isobutyl ketone, 1-butanol+ methyl ethyl ketone,
and 1-butanol+methyl propyl ketone systems was measured using a circulation type equilibrium apparatus at atmospheric pressure.
The measured data and literature data for alcohol and ketone systems have been correlated by the UNIversal Quasi-Chemical
(UNIQUAC) model with two binary interaction parameters and the non-random lattice fluid equation of state with hydrogen bonding
equation of state (NLF-HB EoS) using a single binary interaction parameter. For the NLF-HB EoS calculations, the numbers of
proton acceptor for ketones were adjusted between 0 and 1. The calculation results with the NLF-HB EoS are better than those
with the UNIQUAC model. 相似文献
93.
Moumita Mukherjee Biswanath Mukherjee Youngill Choi Kyoseung Sim Junghwan Do Seungmoon Pyo 《Synthetic Metals》2010,160(5-6):504-509
We report a copper hexadecafluorophthalocyanine (F16CuPc) based n-type organic field-effect transistor (OFET) with polymeric gate dielectrics with different physical/electrical properties. The gate dielectrics are four types of cross-linked poly(4-vinylphenol) and newly prepared poly(4-phenoxy methyl styrene) and those are characterized based on surface tension, leakage current and capacitance. The performance of F16CuPc OFETs with those gate dielectrics was compared. We found that the composition of the gate dielectrics and the interfacial interaction of F16CuPc with the gate dielectric play a decisive role in the performance of OFETs. The effect of physical/electrical properties, composition and processing condition of the gate dielectrics on the device performance was investigated. 相似文献
94.
Abstract: This article is devoted to the construction of a computational nonlinear thermomechanical model of large light partition walls made up of cardboard‐plasterboard‐cardboard (CPC) plates screwed to a metallic frame, and is submitted to mechanical and thermal loadings induced by fire. The computational model, based on experimental analysis and a probabilistic modeling, is developed for the prediction of a large light partition wall for (1) its linear thermal behavior, (2) its nonlinear mechanical behavior, and (3) its nonlinear thermomechanical behavior. 相似文献
95.
96.
Formation and Accumulation of Intragranular Pores in the Hydrothermally Synthesized Barium Titanate Nanoparticles 下载免费PDF全文
Changyeon Baek Ji Eun Wang San Moon Chang‐Hak Choi Do Kyung Kim 《Journal of the American Ceramic Society》2016,99(11):3802-3808
As highly integrated circuits are demanded for high‐performance electric devices, small sizes of barium titanate (BaTiO3) as a dielectric material are desirable for the application of multilayer ceramic capacitors. Since the small sizes of the particles degrade the dielectric property, especially below a certain critical size, understanding the probable cause is significant for the high‐performance capacitors. Here, we have demonstrated nanosized BaTiO3 with average size below 30 nm and a uniform size distribution. High‐resolution transmission electron microscopy (TEM) shows that the as‐synthesized BaTiO3 contains intragranular pores. We have analyzed the correlation between the intragranular pores inside nanoparticles and their phase ratio of cubic and tetragonal. We have found that the presence of the intragranular pores affects low tetragonality of BaTiO3 particles, and the intragranular pores are generated by the accumulation of hydroxyl groups during hydrothermal reaction. Formation and accumulation of intragranular pores have been investigated by ex‐situ synchrotron X‐ray diffraction and TEM analysis, suggesting the phase evolution model of nanosized BaTiO3. 相似文献
97.
Jong Min Byun Su-Ryong Bang Chun Woong Park Myung-Jin Suk Young Do Kim 《Metals and Materials International》2016,22(1):81-86
In general, size, shape and dispersion of phases in alloys significantly affect mechanical properties. In this study, the mechanical properties of Mo-Si-B alloys were experimentally investigated with regards to the refinement of intermetallic compound. To confirm the size effect of the intermetallic compound phases on mechanical properties, two differently sized intermetallic compound powders consisting Mo5SiB2 and Mo3Si were fabricated by mechano-chemical process and high-energy ball milling. A modified powder metallurgy method was used with core-shell intermetallic powders where the intermetallic compound particles were the core and nano-sized Mo particles which formed by the hydrogen reduction of Mo oxide were the shells, leading to the microstructures with uniformly distributed intermetallic compound phases within a continuous α-Mo matrix phase. Vickers hardness and fracture toughness were measured to examine the mechanical properties of sintered bodies. Vickers hardness was 472 Hv for the fine intermetallic compound powder and 415 Hv for the coarse intermetallic compound powder. The fracture toughness was 12.4 MPa·√m for the fine IMC powders and 13.5 MPa·√m for the coarse intermetallic compound powder. 相似文献
98.
Doğuş Özkan Yaman Erarslan Egemen Sulukan Levent Kara M. Alper Yılmaz M. Barış Yağcı 《Tribology Letters》2018,66(4):152
In this study, ~?3.5 µm thick multilayer titanium alumina nitride (TiAlN), alumina titanium nitride (AlTiN), and alumina chromium nitride (AlCrN) coatings were deposited on the H13 steel surface by cathodic arc physical vapor deposition (CAPVD) method. The tribological performance of the coatings was evaluated by a tribometer at boundary lubrication condition. Then, coating surfaces were observed by optical microscope, optical profilometer, and atomic force microscope to evaluate the morphological changes, wear volumes, and tribofilm thickness. Also, scanning electron microscopy (energy dispersive X-ray) and X-ray photoelectron spectrometry analyses were applied to coating surfaces for the tribochemical evolution of the tribofilm. Results showed that AlCrN coating performed the best tribological behavior at boundary lubricated condition, when compared to TiAlN and AlTiN coatings and it can be used as a wear resistant cam tappet coating in internal combustion engines. 相似文献
99.
Fatih Doğan 《Polymer Engineering and Science》2014,54(5):992-1002
In this study, the kinetic parameters and reaction mechanism of decomposition process of oligo(4‐hydroxyquinoline) synthesized by oxidative polymerization were investigated by thermogravimetric analysis (TGA) at different heating rates. TGA‐derivative thermogravimetric analysis curves showed that the thermal decomposition occurred in two stages. The methods based on multiple heating rates such as Kissinger, Kim–Park, Tang, Flynn–Wall–Ozawa method (FWO), Friedman, and Kissinger–Akahira–Sunose (KAS) were used to calculate the kinetic parameters related to each decomposition stage of oligo(4‐hydroxyquinoline). The activation energies obtained by Kissinger, Kim–Park, Tang, KAS, FWO, and Friedman methods were found to be 153.80, 153.89, 153.06, 152.62, 151.25, and 157.14 kJ mol?1 for the dehydration stage, 124.7, 124.71, 126.14, 123.75, 126.19, and 124.05 kJ mol?1 for the thermal decomposition stage, respectively, in the conversion range studied. The decomposition mechanism and pre‐exponential factor of each decomposition stage were also determined using Coats–Redfern, van Krevelen, Horowitz–Metzger methods, and master plots. The analysis of the master plots and methods based on single heating rate showed that the mechanisms of dehydration and decomposition stage of oligo(4‐hydroxyquinoline) were best described by kinetic equations of An mechanism (nucleation and growth, n = 1) and Dn mechanism (dimensional diffusion, n = 6), respectively. POLYM. ENG. SCI., 54:992–1002, 2014. © 2013 Society of Plastics Engineers 相似文献
100.
Safa Karaman Omer Said Toker Mustafa Çam Mahmut Doğan Ahmed Kayacier 《Drying Technology》2014,32(3):258-267
In this study, the effects of three different drying methods (freeze drying, oven drying, and vacuum oven drying) on bioactive (total phenolics, total flavonoids, condensed tannin and total hydrolyzable tannin contents, antiradical activity, and antidiabetic activity) and some physicochemical (dry matter, ash, water activity (a w ), color, protein, hydroxymethylfurfural, glucose and fructose content) properties of persimmon fruit were investigated. Simplex lattice mixture design methodology was applied to determine the best solvent mixture for the extraction of phenolics from the samples. It was found that the mixture of acetone:water at the ratio of 50:50 % (v/v) was the best solvent mixture for the extraction. The persimmon powder sample obtained from freeze drying showed significantly (p <0.05) higher bioactivity values than oven- and vacuum-oven-dried samples. Antiradical activity changed significantly depending on the drying method employed and it was superior in freeze-dried samples than that of the other drying methods. 相似文献