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51.
Sang Hern Kim Won Keun Son Yong Joo Kim Eu‐Gene Kang Dong‐Won Kim Chang Woo Park Whan‐Gi Kim Hyung‐Joong Kim 《应用聚合物科学杂志》2003,88(3):595-601
A polystyrene (PS)/poly(butyl acrylate) (PBA) composite emulsion was produced by seeded emulsion polymerization of butyl acrylate (BA) with PS seed particles which were prepared by emulsifier‐free polymerization of styrene with potassium persulfate (KPS) under a nitrogen atmosphere at 70°C for 24 h with stirring at 60 rpm and swelled with the BA monomer in an ethanol/water medium. The structure of the PS/PBA composite particles was confirmed by the presence of the characteristic absorption band attributed to PS and PBA from FTIR spectra. The particles for pure PS and PS/PBA with a low content of the BA monomer were almost spherical and regular. As the BA monomer content was increased, the particle size of the PS/PBA composite particles became larger, and more golf ball‐like particles were produced. The surface morphology of the PS/PBA composite particles was investigated by AFM and SEM. The Tg's attributed to PS and PBA in the PS/PBA composite particles were found at 110 and ?49°C, respectively. The thermal degradation of the pure PS and PS/PBA composite particles occurred in one and two steps, respectively. With an increasing amount of PBA, the initial thermal decomposition temperature increased. On the contrary the residual weight at 450°C decreased with an increasing amount of PBA. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 595–601, 2003 相似文献
52.
Effect of Sintering Temperature on Thermoelectric Properties of p‐Bi2Te3 Alloys Produced by Gas Atomization 下载免费PDF全文
Babu Madavali Hyo‐Seob Kim Min‐Gyu Choi Gi‐Chan Park Jar‐Myung Koo Hyeon‐Taek Son Soon‐Jik Hong 《International Journal of Applied Ceramic Technology》2016,13(2):245-251
In this research, p‐type Bi2Te3–75% Sb2Te3 thermoelectric alloy powders were produced by gas atomization and subsequently sintered by hot pressing at different temperatures. The grain growth of the hot‐pressed samples was observed with increasing sintering temperature from 380°C to 460°C. The compressive strength increased with increasing hot‐pressing temperature due to the high relative density of bulk samples obtained at high temperatures. The effect of sintering temperature on thermoelectric (TE) properties was studied. The maximum power factor 3.48 mW/mK2 was obtained for the sample hot pressed at 420°C due to the resulting high electrical conductivity and enhanced Seebeck coefficient values. 相似文献
53.
Gyoung Tae Jin Ho-Jung Ryu Sung-Ho Jo Seung-Yong Lee Sung Real Son Sang Done Kim 《Korean Journal of Chemical Engineering》2007,24(3):542-546
To investigate the feasibility of a chemical-looping hydrogen generation system, we investigated the reduction and water splitting
reaction characteristics for three mediators and two reducing gas in a bubbling fluidized bed reactor (0.02 m I.D.). For three
oxygen carrier particles (NiO/bentonite, Fe2O3/bentonite, (NiO:Fe2O3)/bentonite), hydrogen was used as a reduction gas and water was used as an oxidation gas. For (NiO: Fe2O3)/bentonite particle, carbon monoxide, which is the main component in the syngas from coal or heavy residue, was used as a
reducing gas to check reactivity for the carbon containing fuels and carbon deposition characteristics. Based on the reactivity
tests, (NiO: Fe2O3)/bentonite particle was selected as the best mediator for the chemical-looping hydrogen generation system to achieve stable
continuous operation.
This work was presented at the 6
th
Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006. 相似文献
54.
Younggon Son Kalman B Migler 《Polymer》2002,43(10):3001-3006
This paper describes an improvement of the technique to measure interfacial tension in immiscible polymer blends. Our method is based on the droplet retraction method, in which one relates the kinetics of relaxation of a deformed droplet to the interfacial tension between the matrix and droplet. Previously, the problem with this technique has been the difficulty in preparing axisymmetric ellipsoidal droplets. In our work, we demonstrate that perfect axisymmetric ellipsoidal droplets are produced at a later stage of relaxation of short imbedded fibers. With this technique, we utilize the strengths of both the deformed droplet method and the imbedded fiber retraction method while overcoming their shortcomings. The interfacial tension value thus obtained was compared to that by conventional methods. Additionally, the effect of confinement by external walls on the interfacial tension measurement was studied. Confinement affects interfacial tension measurement when the gap between the walls is less than two times the equilibrium drop size. 相似文献
55.
Zinc sulfide [ZnS] thin films were deposited on glass substrates using radio frequency magnetron sputtering. The substrate
temperature was varied in the range of 100°C to 400°C. The structural and optical properties of ZnS thin films were characterized
with X-ray diffraction [XRD], field emission scanning electron microscopy [FESEM], energy dispersive analysis of X-rays and
UV-visible transmission spectra. The XRD analyses indicate that ZnS films have zinc blende structures with (111) preferential
orientation, whereas the diffraction patterns sharpen with the increase in substrate temperatures. The FESEM data also reveal
that the films have nano-size grains with a grain size of approximately 69 nm. The films grown at 350°C exhibit a relatively
high transmittance of 80% in the visible region, with an energy band gap of 3.79 eV. These results show that ZnS films are
suitable for use as the buffer layer of the Cu(In, Ga)Se2 solar cells. 相似文献
56.
Woo Hyung Jeon Jeong‐Yu Son Sun‐Eung Kim Phil Ho Lee 《Advanced Synthesis \u0026amp; Catalysis》2015,357(4):811-817
An efficient phosphaannulation via palladium(II)‐catalyzed C H activation/oxidative cyclization by the 6‐endo mode is reported for the synthesis of 3‐substituted phosphaisocoumarins from the reaction of arylphosphonic acids with unactivated alkenes under aerobic conditions. Also, α,α‐disubstituted benzylphosphonic acids were phosphaannulated with unactivated alkenes, producing phosphaisochromanones having (Z)‐alkylidenyl groups via anti‐phosphoryloxypalladation by the 6‐exo mode.
57.
Robert S. Janesheski Lori J. Groven Steven F. Son 《Propellants, Explosives, Pyrotechnics》2014,39(4):609-616
Typically characterizing home made explosives (HMEs) requires many large scale experiments, which is prohibitive given the large number of materials in use. A small scale experiment was developed to characterize HMEs such as ammonium nitrate‐fuel oil mixtures. A microwave interferometer is applied to small scale confined transient experiments, yielding time resolved characterization of a failing detonation that is initiated with an ideal explosive booster charge. Experiments were performed with ammonium nitrate and two fuel compositions (diesel fuel and mineral oil). It was observed that the failure dynamics were influenced by factors such as the chemical composition, confiner thickness, and applied shock wave strength. Thin steel walled confiners with 0.71 mm wall thickness experienced detonation failure and decoupling of the shock wave from the reaction zone. Confiners with a wall thickness of 34.9 mm showed a decrease in propagation speed and a steady reactive wave was achieved. Varying the applied shock strength by using an attenuator showed corresponding changes in the initial overdriven reactive wave velocity in the HMEs. The distance to detonation failure was also shown to depend on the attenuator length when thin wall confinement was used. This experimental method is shown to be repeatable and can be performed with little required material (about 2 g). The data obtained could be useful to model development and validation, as well as quantifying detonability of materials. 相似文献
58.
Van Son Nguyen Laurent Badie Emmanuel Lamouroux Brice Vincent Fabrice Domingues Dos Santos Maëlen Aufray Yves Fort Didier Rouxel 《应用聚合物科学杂志》2013,129(1):391-396
Piezoelectric films were prepared by incorporation of lithium niobate (LiNbO3) nanoparticles into copolymer of vinylidene difluoride and trifluoroethylene. Nanoparticles of LiNbO3 with ferroelectric phase were successfully synthesized and dispersed homogenously by ultrasonication in the copolymer matrix without any surfactant or surface functionalization. The nanocomposites were fully characterized by electronic microscopy, X‐ray diffraction, differential scanning calorimetry, dynamical mechanical analysis, and piezometer. Surprisingly, the copolymer matrix crystallinity and morphology were not affected by the incorporation of nanoparticles. Therefore the nanocomposites remained good mechanicals properties and high ferroelectricity coupled to nonlinear optical activity thanks to the noncentro symmetric space group of lithium niobate. This could be a novel approach to develop new multifunctional materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
59.
Mieon Son Yuri Lee Heeyong Hwang Dr. Soonsil Hyun Prof. Jaehoon Yu 《ChemMedChem》2013,8(10):1573-1573
60.
Ik Sang Shin Sung Mo Son Dae Ho Lim Yong Kang Heon Jung Ho Tae Lee 《Korean Journal of Chemical Engineering》2010,27(3):1015-1020
Characteristics of heat transfer were investigated in pressurized slurry bubble column reactors whose diameter was either
0.051, 0.076, 0.102 or 0.152 m (ID) and 1.5 m in height, respectively. Effects of gas velocity (U
G
), solid contents (S
C
), pressure (P), liquid viscosity (μ
L
) and column diameter (D) on the heat transfer coefficient (h) between the immersed vertical heater and the column were determined.
Multiple effects such as UG and D, P and D, μ
L
and D, and S
C
and D on the value of heat transfer coefficient were discussed. Temperature fluctuations were also measured and analyzed
by adapting chaos theory, which was used to explain the effects of operating variables on the heat transfer in the column.
The heat transfer coefficient increased with increasing gas velocity, pressure or solid content in the slurry phase, but decreased
with increasing liquid viscosity or column diameter. The decrease trend of h with increasing column diameter was somewhat
sensitive when the gas velocity was relatively high (U
G
⩾12 cm/s). The effects of column diameter on the h value became almost linear when the operating pressure (P=4−10 kg
f
/cm2), liquid viscosity (μ
L
=20−38 mPa·s) or solid content in the slurry phase (S
C
=10−20 wt%) was relatively high and gas velocity was relatively low, within these experimental conditions. The heat transfer
coefficient was well correlated in terms of dimensionless groups as well as operating variables. 相似文献