• Title/Summary/Keyword: CMK-3

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Synthesis of Mesoporous TS-1 for Catalytic Oxidative Desulfurization

  • Park, Chul-Woo;Kim, Tae-Kyung;Ahn, Wha-Seung
    • Bulletin of the Korean Chemical Society
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    • v.30 no.8
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    • pp.1778-1782
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    • 2009
  • Mesoporous TS-1 catalysts were prepared via a nanocasting route using two different carbon template sources of CMK-3 and commercial carbon black. Products were characterized by XRD, UV-Vis spectroscopy, SEM, TEM, and $N_2$ adsorption- desorption measurement. The catalytic performances of the samples for allylchloride epoxidation and oxidative desulfurization of the representative refractory sulfur compounds, dibenzothiophene and 4,6-dimethyldibenzothiophene, were compared against those of conventional TS-1. Whilst the allychloride epoxidation activity for the mesoporus TS-1 samples were similar, mesoporous TS-1 exhibited significantly higher catalytic activities than conventional TS-1 in oxidative desulfurization.

Study on the Antibiotic Effect of Casual Shoe Usage Leather (Casual Shoe용 피혁의 항균성에 관한 연구)

  • Shin, Soo-Beom;Min, Byung-Wook;Heo, Jong-Soo;Kim, Won-Ju
    • Applied Biological Chemistry
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    • v.44 no.4
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    • pp.257-261
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    • 2001
  • Leather (skin & hide) is a body organ, comprising 3 to 5% of the animals weight. The cross-section of a leather is composed of two major divisions: the epidermis or grain layer and the corium or split layer. The leather is naturally covered with bacteria and fungi, because it is a particularly rich source of a wide variety of microorganisms. Stains or coatings of different colours occur in patches or over large areas, depending on the type of mould spore infestation. We examined the antibiotic effect of leather after washing. Upon applying equal fungicide, antibiotic effects increased as follows: grain layer>middle layer>flesh layer. Antibiotic effect decreased with increasing frequency of washing. Decrease in antibiotic effect was lower in OITZ fungicide than in TCMTB and CMK fungicides. Sulfated fatliquor showed higher antibiotic effect than phosphated fatliquor.

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Ginsenoside Rh2 Induces Apoptosis via Activation of Caspase-1 and -3 and Up-Regulation of Bax in Human Neuroblastoma

  • Kim, Young-Soak;Jin, Sung-Ha
    • Archives of Pharmacal Research
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    • v.27 no.8
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    • pp.834-839
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    • 2004
  • In human neuroblastoma SK-N-BE(2) cells undergoing apoptotic death induced by ginsenos-ide Rh2, a dammarane glycoside that was isolated from Panax ginseng C. A. Meyer, caspase-1 and caspase-3 were activated. The expression of Bax was increased in the cells treated with ginsenoside Rh2, whereas Bcl-2 expression was not altered. Treatment with caspase-1 inhibi-tor, Ac-YVAD-CMK, or caspase-3 inhibitor, Z-DEVD-FMK, partially inhibited ginsenoside Rh2-induced cell death but almost suppressed the cleavage of the 116 kDa PARP into a 85 kDa fragment. When the levels of p53 were examined in this process, p53 accumulated rapidly in the cells treated early with ginsenoside Rh2. These results suggest that activation of caspase-1 and -3 and the up-regulation of Bax are required in order for apoptotic death of SK-N-BE(2) cells to be induced by ginsenoside Rh2, and p53 plays an important role in the pathways to promote apoptosis.

Redundancy resolution method of omni-directional mobile manipulator system (전방향 이동 머니퓰레이터 시스템의 여유자유도 최적화 방법)

  • Kwon, Soon-Jae;Jeong, Jae-Ung
    • Journal of Power System Engineering
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    • v.19 no.3
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    • pp.75-80
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    • 2015
  • Typically, robot system configured by articulated robot manipulator with 1 DOF transfer unit is being applied in automotive manufacturing automation process. Especially, 1 DOF transfer unit is necessary to extend workspace of robot manipulator. In this configuration, because transfer unit works only one direction, robot manipulator only works in one side in case of car body painting or sealing automation process. it is necessary three robot manipulator system at least. In this paper, in order to robot manipulator works effectively in car body sealing automation application, we are suggested omni-directional manipulator system and conducted studying on redundancy resolution method to solve manipulability-optimal problem.

Numerical simulation of the total hip prosthesis under static and dynamic loading (for three activities)

  • Mohammed El Sallah Zagane;Abdelmadjid Moulgada;Murat Yaylaci;Sahli Abderahmen;Mehmet Emin Ozdemir;Ecren Uzun Yaylaci
    • Structural Engineering and Mechanics
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    • v.86 no.5
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    • pp.635-645
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    • 2023
  • This study aims to simulate the mechanical behavior of the total prosthesis model of Charnley (CMK3) by the 3D finite element method and to determine the state of the stresses in the femoral components (prosthesis, cement, and bone). The components are subjected to a dynamic load due to three activities (normal walking, climbing stairs, and standing up a chair). Static loading is by selecting the maximum load for the same activities mentioned. The results show that the maximum stresses in the proximal part of the cement are very important. Moreover, new results obtained for different parameters were discussed in detail. It is understood that current research provides important lessons for the surgeon to contribute to the clinical diagnosis of durable implantations and a better understanding of the process of bone remodeling and bone prosthesis.

Numerical modeling of the damaged cement orthopedic in three variants of total hip prostheses

  • Cherfi Mohamed;Zagane Mohammed El Sallah;Moulgada Abdelmadjid;Ait Kaci Djafar;Benouis Ali;Zahi Rachid;Sahli Abderahmen
    • Structural Engineering and Mechanics
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    • v.91 no.3
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    • pp.251-262
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    • 2024
  • Numerical modeling using the finite element method (FEM) offers crucial insights into the mechanical behavior of prostheses, including stress and strain distribution, load transfer, and stress intensity factors. Analyzing cracking in PMMA surgical cement (polymethylmethacrylate) for total hip prostheses (THP) is essential for understanding the loosening phenomenon, as the rupture of orthopedic cement is a primary cause. By understanding various failure mechanisms, significant advancements in cemented total prostheses can be achieved. This study performed a numerical analysis using a 3D FEM model to evaluate stress levels in different THP models, aiming to model damage in the orthopedic cement used in total hip arthroplasty. Utilizing ABAQUS software, FEM, and XFEM, the damage in three types of THPs-Charnley (CMK3), Osteal (BM3), and THOMPSON was modeled under stumbling loading conditions. XFEM allowed for the consideration of crack propagation between the cement and bone, while the GEARING criterion employed a user-defined field subroutine to model damage parameters. The study's findings can contribute to improving implant fixation techniques and preventing postoperative complications in orthopedic surgery.

A Study on The Effects of Three Different Carbon Catalysts on Performance of Vanadium Redox Flow Battery (세가지 다른 형태의 탄소촉매 적용에 따른 바나듐레독스흐름전지 성능 변화에 관한 연구)

  • Chu, Cheounho;Jeong, Sanghyun;Jeong, Jooyoung;Chun, Seung-Kyu;Lee, Jinwoo;Kwon, Yongchai
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.2
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    • pp.170-178
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    • 2015
  • In this study, we carry out a study on how to improve performance of vanadium redox flow battery (VRFB) through promoting reaction rate of rate determining vanadium reaction ($[VO]^{2+}/[VO_2]^+$). In order to do that, three different carbons like Vulcan (XC-72), CMK3 and MSU-F-C are adopted as the catalysts, while their catalytic activity and reaction reversibility are evaluated using half-cell tests. Their topological images are also measured by TEM. For estimation of the VRFB performance, multiple charge-discharge curves of VRFBs including the catalysts are measured by single cell tests. As a result of that, MSU-F-C shows relatively excellent catalytic activity and reaction reversibility as well as large surface area compared to those of Vulcan (XC-72) and CMK3. Also, in terms of the performance of VRFBs including the catalysts, VRFB including MSU-F-C indicates (i) low charging/discharging overpotentials and low internal resistance, (ii) high charge/discharge capacities and (iii) high energy efficiency. These VRFB performance data are well agreed with results on catalytic activity and reaction reversibility. The reason that MSU-F-C induces superior VRFB performances is attributed to (i) its large surface area and (ii) its hydrophilic surface functional groups that mainly consist of hydroxyl bonds that are supposed to play active surface site role for facilitaing $[VO]^{2+}/[VO_2]^+$ redox reaction. Based on the above results, it is found that adoption of MSU-F-C as catalyst for VRFB results in improvement in VRFB performance by promoting the languid $[VO]^{2+}/[VO_2]^+$ redox reaction.

China's Ascent in World Trade and Associated Shift in Its Trade Structure

  • Rao, D. Tripati;Pathak, Ravi
    • The Journal of Asian Finance, Economics and Business
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    • v.3 no.3
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    • pp.39-55
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    • 2016
  • The rapid expansion of China's trade surplus since the mid-eighties and picking up until the onset of 2008-09 global financial crisis has been a key development in the world economy. While growing trade surplus of China has been viewed with cynicism borne out of an undervalued Yuan and for having being a member of WTO since 2001, many others argue that China's trade surplus reflect changes in China's economic and trade structure and associated shifts in its role within regional and global production chains. We address this issue by analyzing: (i) China's growing and changing trade structure as well as changing structure of trade surplus with the rest of the world, USA, Europe, Japan and rest of Asia, (ii) China's revealed comparative advantage (RCA) with the rest of the world, and (iii) how China's trade policies resulted into a shift in China's trade structure. We find that, not only China has made significant inroads in the world trade since its admission to WTO, but also there has been a noticeable shift in China's trade structure with specialization in high-end technology industries wherein China's exports aided by a well calibrated FDI policy.

Fabrication of nitrogen doped ordered mesoporous carbon derived from glucosamine with hybrid capacitive behaviors

  • Zhang, Deyi;Han, Mei;Li, Yubing;Wang, Bing;Wang, Yi;Wang, Kunjie;Feng, Huixia
    • Carbon letters
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    • v.23
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    • pp.9-16
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    • 2017
  • This paper introduces a nitrogen-doped ordered mesoporous carbon (NOMC) derived from glucosamine with hybrid capacitive behaviors, achieved by successfully combining electrical double-layer capacitance with pseudo-capacitance behaviors. The nitrogen doping content of the fabricated NOMC reached 7.4 at% while its specific surface area ($S_{BET}$) and total pore volume reached $778m^2g^{-1}$ and $1.17cm^3g^{-1}$, respectively. A dual mesoporous structure with small mesopores centered at 3.6 nm and large mesopores centered at 9.9 nm was observed. The specific capacitance of the reported materials reached up to $328Fg^{-1}$, which was 2.1 times higher than that of pristine CMK-3. The capacitance retention rate was found to be higher than 87.9% after 1000 charge/discharge cycles. The supplementary pseudocapacitance as well as the enhanced wettability and conductivity due to the incorporation of nitrogen heteroatoms within the carbon matrixes were found to be responsible for the excellent capacitive performance of the reported NOMC materials.