• Title/Summary/Keyword: structural reaction

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$SO_3$ decomposition over Cu/Fe/$Al_2O_3$ granules with controlled size for hydrogen production in SI thermochemical cycle (황-요오도 열화학 수소제조 공정에서 다양한 크기의 Cu/Fe/$Al_2O_3$ 구형 촉매를 이용한 삼산화항 분해)

  • Yoo, Kye-Sang;Jung, Kwang-Deog
    • Journal of Hydrogen and New Energy
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    • v.19 no.3
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    • pp.226-231
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    • 2008
  • Cu/Fe/$Al_2O_3$ granules with various sizes have been prepared by a combination of sol-gel and oil drop method for the use in sulfur trioxide decomposition, a subcycle in thermochemical sulfur-iodine cycle to split water in the hydrogen and oxygen. The size of composite granules have been mainly changed by the flow-rate of the gel mixture before dropping in the synthesis. The structural properties of the samples were comparable with granule size. In the reaction, the catalytic activity was enhanced by decreasing size in the entire reaction temperature ranges.

Effects of Acid Fog and CaCl2 on the Corrosion Fatigue Strength of Structural Steel (구조용 강재의 부식피로 강도에 미치는 산성안개 및 염화칼슘의 영향)

  • Kim, Min-Gun;Kim, Myoung-Sub
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.17-26
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    • 2001
  • The fatigue strength of SM55C has significantly decreased by 83% compared with atmosphere where distilled exists due to strong erosive action of acid fog. The reason is inferred in a way that strong acid erosive material such as acid fog act and give rise to multi-site crack on the surface. Several fatigue clacks occurred under the acid fog repeat the process of division and unification on the surface and form a long non-propagating crack throughout the circumference of experimented steel. However, in the depth, many parts do not show much trace of unification, and the depth is not as big as the one of normal crack shape. 10% of $CaCl_2$ causes strong erosive reaction to material. Then eventually make the life of fatigue shooter. On the other hand, 20% of $CaCl_2$ beings about oxidized material organic crack closing due to weak erosive reaction.

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Acylation of Wool Keratin with Dibasic Acid Anhydrides - on reaction mechanism - (2염기산 무수물에 의한 양모섬유의 아실화(I) - 반응메카니즘을 중심으로 -)

  • 신은주;박찬헌;최석철
    • Textile Coloration and Finishing
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    • v.7 no.1
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    • pp.65-71
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    • 1995
  • Wool yarns were treated in dimethylformamide solutions containing various concentrations of three dibasic acid anhydrides : succinic, itaconic, and phthalic anhydrides in various conditions. The structural aspects of these dibasic acid anhydrides are different : the succinic, itaconic, and phthalic acid anhydrides have saturated aliphatic etylene, unsaturated aliphatic vinyl and aromatic phenyl groups, respectively. The reaction mechanism of the acylation of wool keratin and some resction conditions were invastigated. And the results are as follows. 1. The N-acylation and formation of free carboxyl group were dominant rather than the O-acylation cross-linked on the side chain of polypeptide. The acylation of wool keratin is easier than that of silk fibroin. 2. The higher molecular weight, steric hinderance and resonance caused lower acylating reactivity. By the determination of acyl contents for acylated keratin, it was rerealed that the degree of acylation was succinic acid anhydride > itaconic acid anhhydride > phthalic acid anhydride.

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Synthesis of Cobalt Oxide Film by Thermal Decomposition for Potential Various Applications

  • Han, Seong Ho;Park, Bo Keun;Son, Seong Uk;Kim, Chang Gyoun;Chung, Taek-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.365.1-365.1
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    • 2014
  • Cobalt oxide has excellent various properties such as high catalytic activity, antiferromagnetism, and electrochromism. So cobalt oxides offer a great potential for their applications in the various areas such as optical gas sensor, catalysts for oxidation reaction, electrochromic devices, high temperature solar selective absorbers, magnetic materials, pigment for glasses and ceramics, and negative electrodes for lithium-ion batteries. We have synthesized novel cobalt complexes by simple reaction of cobalt bistrimethylsilylamide as a starting material with a lot of conventional ligands as potential cobalt oxide precursors. The studies include the facile preparation, structural characterization, and spectroscopic analysis of the new precursors. We are making efforts to grow cobalt oxide thin films using cobalt complexes newly synthesized in this study using deposition techniques.

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The Effect of Wind Load on the Stability of a Container Crane (풍하중이 컨테이너 크레인의 안정성에 미치는 영향 분석)

  • Lee Seong Wook;Shim Jae Joon;Han Dong Seop;Park Jong Seo;Han Geun Jo;Lee Kwon Soon;Kim Tae Hyung
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.2
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    • pp.148-155
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    • 2005
  • This study was carried out to analyze the effect of direction of wind load and machinery house location on the stability of container crane loading/unloading a container on a vessel. The overturning moment of container crane under wind load at 50m/s velocity was estimated by analyzing reaction forces at each supporting point. And variations of reaction forces at each supporting point of a container crane were analyzed according to direction of wind load and machinery house location. The critical location of machinery house was also investigated to install a tie-down which has an anti-overturning function of container crane at the land side supporting point.

Investigation of Polyesters by Time-of-Flight Secondary Ion Mass Spectrometry

  • Lee, Yeonhee;Han, Seunghee;Hercules, David M.
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.715-722
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    • 1995
  • The structural characterization for series of polyesters has been done by time-of-flight secondary ion mass spectrometry (TOF-SIMS). Polymer fragments and intact oligomers composed of large numbers of repeat units have been investigated. Transesterification of polyesters in trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CFA) was monitored and reaction products were identified using TOF-SIMS. The shapes and intensities of clusters in transesterification spectra show good agreement with the theoretical isotope pattern. TOF-SIMS spectra were used to obtain information about the progress of the transesterification reaction.

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항바이러스제가 단백질의 구조적 거동에 미치는 영향에 대한 유한요소법 기반 분석

  • Yun, Gi-Seok;Kim, Jae-Hun
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.212-216
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    • 2015
  • Oseltamivir, also known as Tamifu, is an inhibitor of neuraminidase protein which plays an essential role in proliferation and replication of influenza virus. Binding to the active site of neuraminidase, the oseltamivir prevents the protein from enzyme reaction. Conformational change of the protein(neuraminidase) should be accompanied by the enzyme reaction, but the drug inhibits the protein to deform. In this study, we examine the influence of oseltamivir on protein's conformational change in the structural and mechanical point of view. Finite element analysis of the protein can be an useful approach to investigate the influence of oseltamivir on the deformation of a protein. We suggest the finite element based protein model, and then perform the linear static analysis with the displacement loading condition based on the first two largest motion which can be obtained from the normal mode analysis. The results show that it takes more energy to change shape of the protein with an oseltamivir attached than the protein without an oseltamivir.

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Study on the Real-Time Walking Control of a Humanoid Robot U sing Fuzzy Algorithm

  • Kong, Jung-Shik;Lee, Eung-Hyuk;Lee, Bo-Hee;Kim, Jin-Geol
    • International Journal of Control, Automation, and Systems
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    • v.6 no.4
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    • pp.551-558
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    • 2008
  • This paper deals with the real-time stable walking for a humanoid robot, ISHURO-II, on uneven terrain. A humanoid robot necessitates achieving posture stabilization since it has basic problems such as structural instability. In this paper, a stabilization algorithm is proposed using the ground reaction forces, which are measured using FSR (Force Sensing Resistor) sensors during walking, and the ground conditions are estimated from these data. From this information the robot selects the proper motion pattern and overcomes ground irregularities effectively. In order to generate the proper reaction under the various ground situations, a fuzzy algorithm is applied in finding the proper angle of the joint. The performance of the proposed algorithm is verified by simulation and walking experiments on a 24-DOFs humanoid robot, ISHURO-II.

Synthesis of Alkoxy Modified Silicone Using Alkali Catalyst

  • Lee, Kangseok;Shim, Sang Eun
    • Elastomers and Composites
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    • v.51 no.2
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    • pp.99-105
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    • 2016
  • Alkoxy modified silicone (PAMS) was synthesized from hydroxyl-terminated polydimethylsiloxane (OH-PDMS) and vinyltrimethoxysilane (VTMO) under alkali catalyst (NaOH and KOH) at room temperature ($25^{\circ}C$) via condensation polymerization. Then, the structural verification of the synthesized PAMS was confirmed using $^1H$-NMR and FT-IR spectroscopy. The reaction rate of PAMSs was studied in terms of the concentration variation of alkali catalyst. The reaction rate increased with the concentration of alkali catalyst, but no correlation between conversion and concentration of alkali catalyst was observed.

Comparison of Characteristics of XLPE for Distribution Power Cables (배전케이블용 XLPE의 특성 비교)

  • 서광석;김종은;이건주;김영호;정진수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.9
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    • pp.671-682
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    • 1998
  • Chemical structure and electrical characteristics of 5 commercial crosslinked polyethylenes (XLPE) used as insulating materials for medium voltage distribution power cables in Korea were investigated. It was found that each XLPE shows different properties depending on the type of XLPE. Chemical structural irregularities of pellets change considerably by crossliking reaction, with some irregularities being disappeared after crosslikeng reaction. It was also found through a solvent extraction study that additives such as crosslinking agent and antioxidants act as major source retarding water tree growth. Low molecular weight polyethylene chains plays a different role in water tree growth of XLPE.

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