• Title/Summary/Keyword: Si(IV)

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An Overview of The Commercialisation of The Spray Forming Process

  • Leatham, Alan
    • Journal of Powder Materials
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    • v.3 no.4
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    • pp.227-232
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    • 1996
  • (i) The development of a metallurgical bond during the spray forming of clad products has offered the possibility of manufacturing large rolls, including those used in hot and cold strip mills. Small rolls are already being produced in Japan. (ii) Technical developments, including the use-of-multi-atomizers have resulted in the elimination of porosity from the internal bore of a sprayed tube. Bimetallic tubing can also be manufactured and the installation of a 4.5 ton tube plant in the USA should provide low operation costs. (iii) Spray forming offers a potentially low cost manufacturing route for superalloy ring/casing components in high strength superalloys. (iv) A large pilot plant has been built for the spray forming of ultra-clean superalloys for turbine disc applications. (v) Using twin-atomizing technology, special steel billets have been spray formed up to 400mm diameter with deposition yields in excess of 90%. (vi) Al/Si alloy extrusion billets with excellent dimensional tolerances are being manufactured for large scale automotive applications. Several new aluminum alloys have also been developed, including high strength, low density and low cocfficient of expansion materials. (vii) New copper alloys have been developed and pilot plants are in operation to produce these alloys once markets have become established.

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Mechanical properties and adiabatic temperature rise of low heat concrete using ternary blended cement

  • Kim, Si-Jun;Yang, Keun-Hyeok;Lee, Kyung-Ho;Yi, Seong-Tae
    • Computers and Concrete
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    • v.17 no.2
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    • pp.271-280
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    • 2016
  • This study examined the mechanical properties and adiabatic temperature rise of low-heat concrete developed based on ternary blended cement using ASTM type IV (LHC) cement, ground fly ash (GFA) and limestone powder (LSP). To enhance reactivity of fly ash, especially at an early age, the grassy membrane was scratched through the additional vibrator milling process. The targeted 28-day strength of concrete was selected to be 42 MPa for application to high-strength mass concrete including nuclear plant structures. The concrete mixes prepared were cured under the isothermal conditions of $5^{\circ}C$, $20^{\circ}C$, and $40^{\circ}C$. Most concrete specimens gained a relatively high strength exceeding 10 MPa at an early age, achieving the targeted 28-day strength. All concrete specimens had higher moduli of elasticity and rupture than the predictions using ACI 318-11 equations, regardless of the curing temperature. The peak temperature rise and the ascending rate of the adiabatic temperature curve measured from the prepared concrete mixes were lower by 12% and 32%, respectively, in average than those of the control specimen made using 80% ordinary Portland cement and 20% conventional fly ash.

A Study on the Gwang On Yeok Ron(廣瘟疫論) (광온역론(廣瘟疫論)에 대(對)한 연구(硏究)(II))

  • Kim, Ju-Tae;Chai, Duck-Won;Park, Hyung-Soon;Lee, Si-Hyeong
    • Journal of the Korean Institute of Oriental Medical Informatics
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    • v.19 no.2
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    • pp.39-55
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    • 2013
  • The main purpose of this thesis is the Korean version of "Gwang On Yeok Ron(廣瘟疫論)". Gwang On Yeok Ron is a specialized book about infectious diseases(瘟疫). The book was compiled by Dae Cheon jang(戴天章) in 1722 who was a medical man in the Qing dynasty. The book consists of four volumes and an appendix. "Gwang On Yeok Ron Vol. I(廣瘟疫論卷之一)" is for the demonstration of colds(傷寒) and infectious diseases through a patient's odor(氣), skin tone(色), tongue(舌), mental state(神) and pulse(脈). Also, it describes the complications(兼證, 夾證) of infectious diseases. "Gwang On Yeok Ron Vol. II(廣瘟疫論卷之二)" describes the external symptoms(表證) of infectious diseases and the remedies. "Gwang On Yeok Ron Vol. III(廣瘟疫論卷之三)" describes the internal symptoms(裏證) of infectious diseases and the remedies. "Gwang On Yeok Ron Vol. IV(廣瘟疫論卷之四)" presents principles for the remedy of infectious diseases, and describes the sequelae(遺證) after the recovery of infectious diseases. "Appendix of Gwang On Yeok Ron(廣瘟疫論方目)" presents 83 prescriptions for the remedy of infectious diseases.

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Syntheses and Structures of 1,2,3-Substituted Cyclopentadienyl Titanium(IV) Complexes

  • Joe, Dae-June;Lee, Bun-Yeoul;Shin, Dong-Mok
    • Bulletin of the Korean Chemical Society
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    • v.26 no.2
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    • pp.233-237
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    • 2005
  • Cyclopentadiene compounds, 2-[CR'R(OMe)]-1,3-Me$_2C_5H_3$ (R, R' = 2,2'-biphenyl, 2) and 2-[CR'R(OSiMe$_3$)]-1,3-Me$_2C_5H_3$ (R, R' = 2,2'-biphenyl, 3; R = ph, R' = ph, 4; R = 2-naphthyl, R' = H, 5) are readily synthesized from 2-bromo-3-methoxy-1,3-dimethylcyclopentene (1). Reaction of the cyclopentadienes with Ti(NMe$_2$)$_4$ in toluene results in clean formation of the cyclopentadienyl tris(dimethylamido)titanium complexes, which are transformed to the trichloride complexes, 2-[CR'R(OMe)]-1,3-Me$_2C_5H_2$}TiCl$_3$ (R, R' = 2,2'-biphenyl, 6) and {2-[CR'R(OSiMe$_3$)]-1,3-Me$_2C_5H_2$}TiCl$_3$ (R, R' = 2,2'-biphenyl, 7; R = ph, R' = ph, 8; R = 2-naphthyl, R' = H, 9). Attempts to form C1-bridged Cp/oxido complexes by elimination of MeCl or Me$_3$SiCl were not successful. X-ray structures of 6, 7 and an intermediate complex {2-[Ph$_2$C(OSiMe$_3$)]-1,3-Me$_2C_5H_2$}TiCl$_2$(NMe$_2$) (10) were determined.

Vascular Plants of Construct-Reserved Site of Ecological Stream, Sohyeoncheon in Gyeongju-si (경주시 생태하천 예정지인 소현천의 관속식물상)

  • You, Ju-Han
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.5
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    • pp.61-79
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    • 2018
  • The purpose of this study is to investigate the flora of Sohyeoncheon which is planned for ecological restoration and river maintenance from upstream to downstream, and also to collect the ecological data to cope with the change of the ecosystem of Sohyeoncheon. The numbers of vascular plants were summarized as 336 taxa including 82 families, 233 genera, 298 species, 1 subspecies, 33 varieties and 4 forms. The rare plants were 3 taxa including Aristolochia contorta Bunge, Prunus yedoensis Matsum.(planting) and Koelreuteria paniculata Laxmann. The Korean endemic plants were 4 taxa including Populus tomentiglandulosa T.B.Lee(planting), Lespedeza maritima Nakai, Forsythia koreana (Rehder) Nakai(planting) and Weigela subsessilis (Nakai) L.H.Bailey. The specific plants by floristic region were 15 taxa including 1 taxon of grade V, grade IV and grade II each, 4 taxa of grade III and 8 taxa of grade I. The naturalized plants were 60 taxa and the invasive alien plants were 3 taxa. The results of analysis by vertical structures showed that naturalized plants included 31 taxa of upstream, 53 taxa of midstream and 38 taxa of downstream. An analysis of crossing structures showed that 2 taxa of water channel, 3 taxa of low waterside, 41 taxa of high waterside and 48 taxa of bank.

Effects of Posteroanterior Mobilization on the Cervical Spine in Patient with Chronic Whiplash-Associated Disorders

  • Park, Si Eun;Kim, Ji Sung;Choi, Wan Suk
    • Journal of International Academy of Physical Therapy Research
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    • v.8 no.1
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    • pp.1122-1127
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    • 2017
  • The purpose of this case study was to identify the effects of posteroanterior (PA) mobilization on the cervical spine in a patient with chronic whiplash-associated disorder (WAD). The subject of this study was a 58-year-old woman who sustained a chronic WAD as a result of a motor vehicle accident two years prior. The subject has progressively worsening neck pain and stiffness. The subject was determined to have a grade IIb WAD the use of the Modified Quebec Classification. The intervention was central and unilateral PA mobilization on the spinous process of C4 and C5. The PA mobilizations were performed at the end of range to Maitland grade IV. The PA mobilization was conducted once daily for a total of eight days. Two sets of measurements were done one before and one after the intervention. Neck pain, cervical stiffness, range of motion and lordosis of the cervical spine were measured. Experimental intervention decreased the neck pain, and increased the neck stiffness and cervical ROM (range of motion) such as flexion, extension, lateral flexion and rotation. X-ray photographs also represented that cervical curvature increased from $35^{\circ}$ to $40^{\circ}$. This study suggested that PA cervical mobilization applied to hronic WAD is effective in decreasing pain, increasing cervical ROM and cervical curvature.

The annealing method of nickel electrode for C-silicon solar cell (결정질 태양전지에서 니켈 전극 사용을 위한 열처리 방안)

  • Jung, W.W.;Kim, S.C.;Kyung, D.H.;Kwon, T.Y.;Lee, Y.S.;Heo, Y.S.;Park, S.I.;Yi, J.S.
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.248-250
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    • 2009
  • 고효율 태양전지를 위한 결정질 태양전지의 구조 중 UNSW에서 개발한 BCSC(buried contact solar cell)가 있는데, 이는 전면 전극을 laser 처리 후 무전해 니켈 도금으로 형성한 것이다. 이같은 전면 전극을 형성하기 위해서는 무전해 nickel 도금 후 열처리가 필수적이다. 우리는 이 공정을 확립하기 위해 결정질 wafer에 후면을 PECVD로 SiNx막을 형성하여 $30\Omega/\square$로 도핑한 후 후면을 불산으로 제거한 상태에서 양면을 니켈 무전해 도금으로 전극을 형성하여 $300^{\circ}C,\;350^{\circ}C,\;400^{\circ}C$에서 각각 3,6,9분간 진행하였다. 그 결과 $400^{\circ}C$에서 3분간 열처리된 sample이 상대적으로 가장 명확한 IV curve를 형성하였다. 이 실험의 결과는 PN 접합 구조에서 전극을 nickel로 사용할 때 유용하게 사용될 수 있다.

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Simulation of the Digital Image Processing Algorithm for the Coating Thickness Automatic Measurement of the TRISO-coated Fuel Particle

  • Kim, Woong-Ki;Lee, Young-Woo;Ra, Sung-Woong
    • Journal of Information Processing Systems
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    • v.1 no.1 s.1
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    • pp.36-40
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    • 2005
  • TRISO (Tri-Isotropic)-coated fuel particle is widely applied due to its higher stability at high temperature and its efficient retention capability for fission products in the HTGR (high temperature gas-cooled reactor), one of the highly efficient Generation IV reactors. The typical ball-type TRISO-coated fuel particle with a diameter of about 1 mm is composed of a nuclear fuel particle as a kernel and of outer coating layers. The coating layers consist of a buffer PyC, inner PyC, SiC, and outer PyC layer. In this study, a digital image processing algorithm is proposed to automatically measure the thickness of the coating layers. An FBP (filtered backprojection) algorithm was applied to reconstruct the CT image using virtual X-ray radiographic images for a simulated TRISO-coated fuel particle. The automatic measurement algorithm was developed to measure the coating thickness for the reconstructed image with noises. The boundary lines were automatically detected, then the coating thickness was circularly by the algorithm. The simulation result showed that the measurement error rate was less than 1.4%.

Chemical Composition and Active Antioxidants of Eucommia ulmoides Oliv. Bark

  • Qu, Guan-Zheng;Si, Chuan-Ling;Yin, Yu;Wang, Myeong-Hyeon
    • Nutritional Sciences
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    • v.9 no.4
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    • pp.330-334
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    • 2006
  • Chemical composition of the Eucommia ulmoides bark, including extractives, proximate, mineral, fatty acid and monosaccharide compositions, was studied The most abundant mineral was calcium (533.17 mg/l00 g). $\alpha-linolenic$ acid (24.7%) and linoleic acid (24.3%), showed higher contents among the fatty acids. Major monosaccharides of E. ulmoides balk were arabinose (13.94 mg/g), xylose (18.91 mg/g) and glucose (119.7 mg/g). From the bark of E ulmoides, four compounds were isolated and their structures were elucidated as caffeic acid (I), kaempferol (II), quercetin (III) and isoquercitrin (IV) by spectroscopic analysis such as NMR and MS, including cellulose TLC and other chemical evidence such as hydrolyzation and acetylation. The antioxidant activities of four isolated compounds were evaluated by DPPH free radical scavenging, hydroxyl scavenging and reducing power assays. The results indicated that all the isolated compounds showed higher DPPH radical scavenging activity than $\alpha-tocopherol$ and BHT that were used as positive controls and these four compounds exhibited considerable reducing power and hydroxyl radical (OH) scavenging activity. Considering from the results above, it suggests that the E. ulmoides bark is a potential natural source of antioxidant material.

Electrophilic Attack of the Phenyl Isocyanate Carbon at the Bridging Imido Nitogen: Preparation and Structure of$ Mo_2({\mu-N(CONPh)Ph})({\mu-NPh)(NPh)_2(S_2CNEt_2)_2$

  • 김경;Lee, Soon W.
    • Bulletin of the Korean Chemical Society
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    • v.19 no.11
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    • pp.1211-1216
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    • 1998
  • Bis(diethyldithiocarbamato)ioxomolybdenum(VI), cis-MoO2(S2CNEt2)2, 1, reacted with chlorotrimethylsilane (Me33SiCl) to give a seven-coordinate, pentagonal bipyramidal complex MoOC12(S2CN]Et2)2, 3, in which the oxo ligand is trans to the chloride ligand and the two chloride ligands are mutually cis. The monooxo molybdenum complex bis(diethyidithiocarbamato)oxomolybdenum(IV), MoO(S2CNEt2)2, 2, reacted with phenyl isocyanate (PhNCO) to give an Mo dimer MO2{μ-N(CONPh)Ph}(μ-NPh)(NPh)2(S2CNEt2)2, 4, which contains an Mo-Mo bond, two diethyldithiocarbamato ligands, two terminal imido (NPh) ligands, and two bridging hnido (NPh) ligands. One of the two bridging NPh ligands seemed to have been attacked by the electrophilic phenyl isocyanate carbon, which suggests that the bridging imido NPh ligand is more nucleophilic than the terminal one. Crystallographic data for 3: monoclinic space group P21/c, a=8.908(l) Å, b=17.509(3) Å, c=12.683(2) Å, β=110.15(1)°, Z=4, R(wR2)=0.0611(0.1385). Crystallographic data for 4-THF: orthorhombic space group P212121, a=17.932(4) Å, b=22.715(5) Å, c=11.802(3) Å, Z=4, R(wR2)=0.0585(0.1286).