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91.
Yeong-Koo?YeoEmail author Sung?Chul?Yi Jae?Yong?Ryu Hong?Kang 《Korean Journal of Chemical Engineering》2004,21(2):358-364
A dynamic model representing the wet-end of a paper mill is developed to characterize its dynamic behavior. The model is based
on the mass balance relationships written for the simplified wet-end white water network. The dynamic response of the wet-end
is influenced both by the white water volume and by the level of wire retention. Effects of key manipulated variables such
as the thick stock flow rate, the ash flow rate and the retention aid rate on the major controlled variables are analyzed
by numerical simulations. It can be said that the consistency of the model with plant data seems to be reasonably good and
can be used as a tool for plant analysis and control. 相似文献
92.
Cheol Park Won Sup Lee Se-Il Go Arulkumar Nagappan Min Ho Han Su Hyun Hong Gon Sup Kim Gi Young Kim Taeg Kyu Kwon Chung Ho Ryu Sung Chul Shin Yung Hyun Choi 《International journal of molecular sciences》2015,16(1):645-659
Evidence suggests that phytochemicals can safely modulate cancer cell biology and induce apoptosis. Here, we investigated the anti-cancer activity of morin, a flavone originally isolated from members of the Moraceae family in human leukemic cells, focusing on apoptosis. An anti-cancer effect of morin was screened with several human leukemic cell lines. U937 cells were most sensitive to morin, where it induced caspase-dependent apoptosis in a dose-dependent manner. It also induced loss of MMP (ΔΨm) along with cytochrome c release, down-regulated Bcl-2 protein, and up-regulated BAX proteins. The apoptotic activity of morin was significantly attenuated by Bcl-2 augmentation. In conclusion, morin induced caspase-dependent apoptosis through an intrinsic pathway by upregulating BAD proteins. In addition, Bcl-2 protein expression is also important in morin-induced apoptosis of U937 cells. This study provides evidence that morin might have anticancer properties in human leukemic cells. 相似文献
93.
Hiroaki Inoue Yuji Arai Tsunao Kishida Ryu Terauchi Kuniaki Honjo Shuji Nakagawa Shinji Tsuchida Tomohiro Matsuki Keiichirou Ueshima Hiroyoshi Fujiwara Osam Mazda Toshikazu Kubo 《International journal of molecular sciences》2015,16(1):1043-1050
Hypoxia-inducible factor (HIF)-2α is considered to play a major role in the progression of osteoarthritis. Recently, it was reported that pressure amplitude influences HIF-2α expression in murine endothelial cells. We examined whether hydrostatic pressure is involved in expression of HIF-2α in articular chondrocytes. Chondrocytes were cultured and stimulated by inflammation or hydrostatic pressure of 0, 5, 10, or 50 MPa. After stimulation, heat shock protein (HSP) 70, HIF-2α, nuclear factor kappa B (NF-κB), matrix metalloproteinase (MMP)-13, MMP-3, and vascular endothelial growth factor (VEGF) gene expression were evaluated. The levels of all gene expression were increased by inflammatory stress. When chondrocytes were exposed to a hydrostatic pressure of 5 MPa, HIF-2α, MMP-13, and MMP-3 gene expression increased significantly although those of HSP70 and NF-κB were not significantly different from the control group. In contrast, HIF-2α gene expression did not increase under a hydrostatic pressure of 50 MPa although HSP70 and NF-κB expression increased significantly compared to control. We considered that hydrostatic pressure of 5 MPa could regulate HIF-2α independent of NF-κB, because the level of HIF-2α gene expression increased significantly without upregulation of NF-κB expression at 5 MPa. Hydrostatic pressure may influence cartilage degeneration, inducing MMP-13 and MMP-3 expression through HIF-2α. 相似文献
94.
Effect of the Magnetostrictive Layer on Magnetoelectric Properties in Lead Zirconate Titanate/Terfenol-D Laminate Composites 总被引:2,自引:0,他引:2
Jungho Ryu Shashank Priya Alfredo Vázquez Carazo Kenji Uchino Hyoun-Ee Kim 《Journal of the American Ceramic Society》2001,84(12):2905-2908
Magnetoelectric laminate composites of piezoelectric/magnetostrictive materials were prepared by stacking and bonding together a PZT disk and two layers of Terfenol-D disks with different directions of magnetostriction. These composites were studied to investigate (i) dependence on the magnetostriction direction of the Terfenol-D disk and (ii) dependence on the direction of the applied ac magnetic field. Three different types of assemblies were prepared by using two types of disks: one with magnetostriction along the radial direction, the other with magnetostriction along the thickness direction. The maximum magnetoelectric voltage coefficient (d E /d H ) of 5.90 V/cm·Oe was obtained for a design where the composite was made by two Terfenol-D layers with a radial magnetostriction direction. 相似文献
95.
The synthesis of a novel interpenetrating chitosan network post‐modified with spiropyran (SP) derivatives has been used to develop photochromic hydrogels. We have synthesized succinyl chitosan polymers containing a considerable number of both amines and carboxylic groups. Their intra/inter molecular amide coupling reactions and postmodification with SP derivatives resulted in the photochromic hydrogels functionalized with chitosan‐based interpenetrating polymer network structures. In this hydrogel system, SPs undergo reversible photoresponsive structural switching between a ring‐closed colorless SP form and a ring‐opened purple merocyanine form under specific light‐irradiation conditions. Notably, the photo‐mediated wettabilities and color intensities of the hydrogels increase by the increment in the molecular weight of SP‐functionalized chitosans. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45120. 相似文献
96.
Hyun-Woo Oh Chan-Seok Yun Jun Hyoung Jeon Ji-Ae Kim Doo-Sang Park Hyung Won Ryu Sei-Ryang Oh Hyuk-Hwan Song Yunhee Shin Chan Sik Jung Sang Woon Shin 《Journal of chemical ecology》2017,43(7):703-711
Diterpene resin acids (DRAs) are important components of oleoresin and greatly contribute to the defense strategies of conifers against herbivorous insects. In the present study, we determined that DRAs function as insect juvenile hormone (JH) antagonists that interfere with the juvenile hormone-mediated binding of the JH receptor Methoprene-tolerant (Met) and steroid receptor coactivator (SRC). Using a yeast two-hybrid system transformed with Met and SRC from the Indian meal moth Plodia interpunctella, we tested the interfering activity of 3704 plant extracts against JH III-mediated Met-SRC binding. Plant extracts from conifers, especially members of the Pinaceae, exhibited strong interfering activity, and four active interfering DRAs (7α-dehydroabietic acid, 7-oxodehydroabietic acid, dehydroabietic acid, and sandaracopimaric acid) were isolated from roots of the Japanese pine Pinus densiflora. The four isolated DRAs, along with abietic acid, disrupted the juvenile hormone-mediated binding of P. interpunctella Met and SRC, although only 7-oxodehydroabietic acid disrupted larval development. These results demonstrate that DRAs may play a defensive role against herbivorous insects via insect endocrine-disrupting activity. 相似文献
97.
Loss reduction plays a critical role in improving both process efficiency and overall profitability. As processes become more complex, loss reduction becomes more challenging and systematic decision-supporting methods are thus needed. This paper illustrates such a method in the context of liquid crystal display (LCD) glass production, which involves a series of chemical processes. Loss-minimizing integer programming models are proposed to compute a cutting pattern that allocates multiple demands to LCD mother glass. Numerical examples from actual LCD glass processes are presented to illustrate the applicability of the proposed method. 相似文献
98.
Byeong Sub Kwak No-Kuk Park Jeom-In Baek Ho-Jung Ryu Misook Kang 《Korean Journal of Chemical Engineering》2017,34(7):1936-1943
We investigated the effect of the oxidation state of Mn in CaMnO3 perovskite particles to improve their oxygen transfer performance for chemical-looping combustion (CLC). Li was introduced in the Ca site of CaMnO3 to increase the Mn oxidation state. Ca1?x Li x MnO3 particles were synthesized by the solid-state method, and the amount of Li added ranged from 0 to 0.015 mol. The structure of the synthesized Ca1?x Li x MnO3 particles was examined using XRD, and all particles were confirmed to have a CaMnO3 perovskite structure. The shape and chemical properties of the prepared particles were characterized by using SEM and CH4-TPD. The binding energy and oxidation state of the different elements in the Ca1?x Li x MnO3 particles were measured by XPS. When Li was added, the oxidation state of Mn in Ca1?x Li x MnO3 was higher than that of Mn in CaMnO3. The oxygen transfer performance of the particles was determined by an isothermal H2-N2/air and CH4-CO2/air redox cycle at 850 °C, repeated ten times, using TGA. All particles showed an oxygen transfer capacity of about 8.0 to 9.0 wt%. Among them, Ca0.99Li0.01MnO3 particles had the best performance and the oxygen transfer capacity under H2-N2/air and CH4-CO2/air atmosphere was 8.47 and 8.75 wt%, respectively. 相似文献
99.
Su-Ryeon Yun Kwang Man Kim Jang Myoun Ko Yongku Kang Kwang Sun Ryu 《Polymer Bulletin》2013,70(11):3011-3018
Doped poly(4,4′-diaminodiphenyl sulfone) (pDDS) is prepared for use as a cathode-active material of lithium secondary batteries by chemical oxidation method using ammonium persulfate initiator. The synthesized pDDS and doped pDDS are characterized by chemical structure analysis using Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Cyclic voltammetry shows that the doped pDDS has a typical pair of redox peaks at 3.75/3.15 V vs. Li/Li+, corresponding to charging/discharging of the lithium ion. The discharge capacity at low current rate (0.05 C-rate) achieves 31.5 and 24.3 mA h g?1 in the initial and 50th cycles, respectively. The doped pDDS also shows good cycle performance and high-rate capability, making it appropriate as a cathode material of lithium secondary batteries. 相似文献
100.
Keisuke Kobayashi Minoru Ryu Yutaka Doshida Youichi Mizuno Clive A. Randall 《Journal of the American Ceramic Society》2013,96(2):531-537
The (1?x)NaNbO3–(x)NaTaO3 solid solution was investigated for x ≤ 0.4 in terms of new high‐temperature and high‐permittivity dielectric system that is suitable for base metal inner electrode capacitor applications. The addition of Ta significantly enhanced the resistivity of the dielectric, resulting in superior resistivity than the dielectrics‐formulated BaTiO3 systems that dominate the multilayer ceramic capacitor dielectric devices. The voltage dependence of the permittivity was also superior to BaTiO3‐based materials, providing higher capacitance at higher temperatures. A transmission electron microscopy study illustrated that the grains had so‐called core‐shell structure. According to the electron diffraction analysis, the core region had an inhomogeneous structure between antiferroelectric and ferroelectric phases, and shell region had an incommensurate ferroelectric‐like structure. The core and shell region had Nb‐ and Ta‐rich composition, respectively, and their interface was compositionally sharp, implying that shell region was formed via a liquid phase during the sintering process with an incongruent Ta dissolution reprecipitation. We anticipate that these or similar materials based on the alkali‐niobate perovskites can be further enhanced to provide capacitor solutions from 150°C to 250°C, which is an important range for a number of new AC–DC invertor and engine control units. 相似文献