• Title/Summary/Keyword: SI Separation

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Recovery of High Purity TiO2 Powder from Ilmenite by Hydrochloric Acid Leaching (타이타늄 철석으로부터 염산 침출에 의한 고순도 이산화 타이타늄 회수)

  • Ahn, Hyeong Hun;Lee, Man Seung
    • Resources Recycling
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    • v.28 no.5
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    • pp.68-73
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    • 2019
  • Ilmenite is one of the principal ores for the production of titanium dioxide. To produce titanium dioxide with purity higher than 99.9% from ilmenite, Ti(IV) should be separated from the dissolved impurities such as Fe(III), Si(IV), and Mn(II) present in ilmenite. In this work, a hydrometallurgical process was investigated to recover pure titanium dioxide from ilmenite by HCl leaching followed by separation and hydrolysis of Ti(IV). An optimum leaching condition was obtained by investigating the effect of HCl concentration, pulp density, and leaching time on the leaching percentage of Ti(IV), Fe(III), Si(IV), and Mn(II). Ammonium hydroxide and sodium hydroxide solutions were employed as neutralizing agents to hydrolyze Ti(IV) from the stripping solution of Ti(IV). Titanium dioxide of the anatase phase was obtained by calcination of the hydrolyzed precipitates with $NH_4OH$ solution. A hydrometallurgical process can be developed to produce pure $TiO_2$ powders from ilmenite.

Discrimination between steam processed and unprocessed Tubers of Gastrodia elata Blume by HPLC

  • Zhao, Bing Tian;Song, Si Whan;Le, Duc Dat;Ma, Eun Sook;Son, Jong Keun;Woo, Mi Hee
    • Analytical Science and Technology
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    • v.32 no.6
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    • pp.217-224
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    • 2019
  • In this study, to evaluate the effectiveness and safety of oral therapy using Gastrodiae Rhizoma, a new HPLC-PDA analysis method was developed for the simultaneous quantitation of the three major components: (1) gastrodin, (2) gastrodigenin, and (3) p-hydroxybenzaldehyde, in steam processed and unprocessed tubers of Gastrodia elata Blume. The clear separation of the three components was achieved on a C18 column (250 × 4.6 mm, 5 ㎛) by gradient elution using water (including 0.1 % formic acid) and acetonitrile as the mobile phase. The flow rate was 1.0 mL/min, and the UV detector wavelength was set at 270 nm. The results demonstrate satisfactory linearity, recovery, precision, accuracy, stability, and robustness. The established HPLC-PDA method was applied to quantify three major compounds in 59 samples of G. elata Blume tubers. Finally, the steam processed and unprocessed tubers of G. elata Blume were successfully distinguished by pattern recognition analysis.

Analgesic Constituent from the Herba of Saururus chinensis ($L_{OUR.})B_{AILL.}$ (삼백초의 진통성분)

  • Park, Si-Kyung;Oh, Gab-Jin;Kim, Hyun-Tae;Kim, Hyun-Jong;Chung, Sun-Gan;Cho, Eui-Hwan
    • YAKHAK HOEJI
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    • v.42 no.3
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    • pp.238-242
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    • 1998
  • For the investigation of bioactive natural products with analgesic activity, we have evaluated various extracts of Saururi Herba (Saururaceae), which has been used in traditiona l medicine for edema, beriberi, jaundice, turbid urine, carbuncle and furuncle. The diethylether extract of this plant was found to show a significant analgesic effect on writhing syndrome in mice. Using bioactivity-guided separation of the diethylether extract, analgesic constituent, (8S, 8`R, 7R, 6`R)-2'-oxo-4,5: 4',5'-bis(methylenedioxy)-${\Delta}^{1,3,5,3'}$-8.8', 7.6', 2.O.5'-neolignan(sauchinone) was isolated and structurally identified by physico-chemical properties and spectroscopic evidences. This compound has good analgesic activity with lower toxicity, as compared to other antipyretic-analgesic drug(acetaminophen).

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A Study on the 'Closed ㄱㄴ Type' of Traditional Folk Housing in Goyang, Gyonggi-do, Focused to Dweller's Life (거주자 생활중심으로 본 경기 고양 전통민가 연구 - 폐쇄형 ㄱㄴ자집을 중심으로 -)

  • Lee, Hee-Bong
    • Journal of architectural history
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    • v.14 no.3 s.43
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    • pp.53-76
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    • 2005
  • Through a field study of the folk houses, 'Closed ㄱㄴ Type' in Goyang-si, Gyonggj-do, focused on the dweller's life by the method of ethnographic interview, observation, and physical survey. L and opposite L type of inner and outer buildings form a closed inner court, and innermost backyard for woman is enclosed by fence. Form and space of the house contains dweller's traditional life. Outer space of a front gate becomes semiprivate space, for thrashing and piling up harvest and raising vegetables and pigs. Confucius principle does not fully dominate dweller's life of ancestral rite at Daecheong floor, and separation of man's and woman's quarter. Superstitious worship activities took place for lord of site and house. In everyday life, Anbang, inner main room, is assigned for parent's quarter instead of woman's quarter, and Geornbang, next room, was for son's family. Anbang has symbolic meaning for a place of deathbed. House contains agricultural activities, crop harvesting, thrashing, putting into storage, hulling rice, and keeping grain near kitchen. At present, rooms are needed more; sheds are made into rooms, rooms are enlarged toward outside, half outside space like Daechong floor becomes interior space by sash screen. And modern facilities of kitchen and bathroom are equipped for convenience. At the end, meaning and generative principle of those forms are discovered.

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Bioconjugation of Poly(poly(ethylene glycol) methacrylate)-Coated Iron Oxide Magnetic Nanoparticles for Magnetic Capture of Target Proteins

  • Kang, Sung-Min;Choi, In-Sung S.;Lee, Kyung-Bok;Kim, Yong-Seong
    • Macromolecular Research
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    • v.17 no.4
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    • pp.259-264
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    • 2009
  • Chemical modification of magnetic nanoparticles(MNPs) with functional polymers has recently gained a great deal of attention because of the potential application of MNPs to in vivo and in vitro biotechnology. The potential use of MNPs as capturing agents and sensitive biosensors has been intensively investigated because MNPs exhibit good separation-capability and binding-specificity for biomolecules after suitable surface functionalization processes. In this work, we demonstrate an efficient method for the surface modification of MNPs, by combining surface-initiated polymerization and the subsequent conjugation of the biologically active molecules. The polymeric shells of non-biofouling poly(poly(ethylene glycol) methacrylate)(pPEGMA) were introduced onto the surface of MNPs by surface-initiated, atom transfer radical polymerization(SI-ATRP). With biotin as a model of biologically active compounds, the polymeric shells underwent successful post-functionalization via activation of the polymeric shells and bioconjugation of biotin. The resulting MNP hybrids showed a biospecific binding property for streptavidin and could be separated by magnet capture.

A Study of Aerodynamic Analysis for the Wind Turbine Rotor Blade using a general CFD code (풍력 발전기용 블레이드 공력해석에 대한 연구)

  • Park, Sang-Gyoo;Kim, Jin-Bum;Yeo, Chang-Ho;Kim, Tae-Woo;Kweon, Ki-Yeoung;Oh, Si-Deok
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.516-520
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    • 2009
  • This study describes aerodynamic characteristics for the HAWT (Horizontal Axis Wind Turbine) rotor blade using general CFD(Computational Fluid Dynamics) code. The boundary conditions for analysis are validated with the experimental result by the NREL (National Renewable Energy Laboratory)/NASA Ames wind tunnel test for S809 airfoil. In the case of wind turbine rotor blade, complex phenomena are appeared such as flow separation and re-attachment. Those are handled by using a commercial flow analysis tool. The 2-equation k-$\omega$ SST turbulence model and transition model appear to be well suited for the prediction. The 3-dimensional phenomena in the HAWT rotor blade is simulated by a commercial 3-D aerodynamic analysis tool. Tip vortex geometry and Radial direction flows along the blade are checked by the analysis.

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Process and Structure Design for High Power Reverse-Conducting Gate Commutated Thyristors (RC- GCTs) (고전압 역도통 Gate Commutated Thyristor (RC-GCT) 소자의 공정 및 구조 설계)

  • Kim, Sang-Cheol;Kim, Eun-Dong;Zhang, Chang-Li;Kim, Nam-Kyun;Baek, Do-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.1096-1099
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    • 2001
  • The basic design structure of RC-GCTs (Reserve-Conducting Gate-Commutated Thyristors) is firstly given in this paper. The bulk of wafer is punch-through (PT) type with high resistivity and narrow N-base width. The photo-mask was designed upon the turn-off characteristics of GCT and solution of separation between GCT and diode part. The center part of Si wafer is free-wheeling diode (FWD) and outer is GCT part which has 240 fingers totally. The switching performance of GCT was investigated by Dessis of ISE. The basic manufacture process of 2500V-4500V RC-GCTs was given in this work. Additionally, the local carrier lifetime control by 5Mev proton irradiation was adopted so as to not only to have the softness of reverse recovering for FWD but for reduction of turn-off losses of GCT as well.

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Comparative Study of Celadon Shards from Gangjin and Buan Kiln Sites (강진과 부안 청자 도편의 비교연구)

  • No, Hyunggoo;Kim, Soomin;Kim, Ungsoo;Cho, Wooseok;Han, Junghwa
    • Journal of the Korean Ceramic Society
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    • v.52 no.1
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    • pp.41-47
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    • 2015
  • Celadon shards from Gangjin and Buan were analyzed for their color, chemistry and microstructures. They exhibited similar chromatic characteristics in a $CIEL^*a^*b^*$ analysis. All of the glazes assessed showed comparable compositional areas, while the bodies from Gangjin shards had higher $RO_2$ concentrations. A high degree of similarity was also noted in the microstructures of the glaze and bodies from both regions. Anorthite crystals appeared in the glaze layer, and phase separation behavior developed around these crystals. This may have been caused by the glaze chemistry and the sintering process given the lengthy heating and cooling time. A Raman analysis indicated higher isolated $SiO_4$ unit ($Q_0$) values for the Buan samples. This can stem from the higher firing temperature or the longer sintering process.

SELDI-TOF MS Combined with Magnetic Beads for Detecting Serum Protein Biomarkers and Establishment of a Boosting Decision Tree Model for Diagnosis of Pancreatic Cancer

  • Qian, Jing-Yi;Mou, Si-Hua;Liu, Chi-Bo
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1911-1915
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    • 2012
  • Aim: New technologies for the early detection of pancreatic cancer (PC) are urgently needed. The aim of the present study was to screen for the potential protein biomarkers in serum using proteomic fingerprint technology. Methods: Magnetic beads combined with surface-enhanced laser desorption/ionization (SELDI) TOF MS were used to profile and compare the protein spectra of serum samples from 85 patients with pancreatic cancer, 50 patients with acute-on-chronic pancreatitis and 98 healthy blood donors. Proteomic patterns associated with pancreatic cancer were identified with Biomarker Patterns Software. Results: A total of 37 differential m/z peaks were identified that were related to PC (P < 0.01). A tree model of biomarkers was constructed with the software based on the three biomarkers (7762 Da, 8560 Da, 11654 Da), this showing excellent separation between pancreatic cancer and non-cancer., with a sensitivity of 93.3% and a specificity of 95.6%. Blind test data showed a sensitivity of 88% and a specificity of 91.4%. Conclusions: The results suggested that serum biomarkers for pancreatic cancer can be detected using SELDI-TOF-MS combined with magnetic beads. Application of combined biomarkers may provide a powerful and reliable diagnostic method for pancreatic cancer with a high sensitivity and specificity.

A Study on the Recovery of Valuable Resources from Abandoned Fold Mine Tailings (금 광산 폐망미로부터 유가자원 회수에 관한 연구)

  • 채영배;정수복;윤평란
    • Resources Recycling
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    • v.8 no.3
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    • pp.37-42
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    • 1999
  • Ths sludy was canied out to recover gold and sllics from abandoned gold mine talings with about 4.5 ghonAu and 84.88 wt% SOz. Tl~bee nef~cialiop~ro~c esses including crushing, screening, magnelic and gravity (humprey sp~rals,h aking table) separation \ulcornervex employed. Results were Feasible to rccovn h e gold concentrates (307.1 gltoilon .4u . 0.60 wr%, 97.7 giton Au : 0.27 wl%, 15.3 &/ton Au . 5.23 wt%, 21.2 g/ton Au : 2.42 wl%) and silica (96.40 wi% SiO\ulcorner yield 60 65 ~ 1 % )

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