• 제목/요약/키워드: SA Removal

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Removal of Iron and Phosphorus from Metallurgical Grade Silicon by Melting with Ca and Aqua Regia Leaching (칼슘 첨가(添加)-용융(溶融) 금속급(金屬級) 실리콘의 왕수(王水) 침출(浸出)에 의한 철(鐵)과 인(憐)의 제거(除去))

  • SaKong, Seong-Dae;Sohn, Ho-Sang
    • Resources Recycling
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    • v.20 no.5
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    • pp.34-39
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    • 2011
  • Metallurgical grade silicon(MG-Si) was melted with Ca at 1500$^{\circ}C$ under Ar atmosphere. The sample was cooled at 10 $^{\circ}C$/min to room temperature and leached in aqua regia. In the present study, the effect of Ca addition and conditions of acid leaching on removal of Fe and P in MG-Si were investigated. CaSi$_2$ phase was formed at the grain boundary of MG-Si melting with Ca. Also FeSi$_2$ phase was precipitated in CaSi$_2$ phase. By the formation of CaSi$_2$ phase, 97% of Fe and 66 % of P were removed from Ca added MG-Si with the particle size of 600~850${\mu}m$ by aqua regia(more than 30%) leaching.

Application of Removable Ground Anchor Using Auto back Equipment (Auto back 인장장치를 이용한 제거식 앵커의 적용성)

  • Lee, Song;Lee, Sung-Won;Park, Sang-Kook;Kim, Sa-Dong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.223-230
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    • 2004
  • It is growing the application of the removal ground anchor with tension force for earth retaining constructions in the downtown. Nowadays, we can find the compression dispersion anchor on many site. But, it is occur some probelems in behabior of anchors because of impossible to tense p.c strand uniformly with existing equipment due to different length of p.c strand. So we tried to tense each p.c strand uniformly with auto back equipment in-situ test. This study compared and analyzed apply to elastic theory in-situ test results of an existing equipment with those of auto back equipment. As a result of the test, It has been proved that differences of tension force in the existing equipment increases with increasing the number of p.c strand. This can cause an ultimate failure of the concentrated p.c strand and a shear failure of ground. So it has been proved that auto back equipment is necessary.

A Study on Certification Method of Health and Barrier Free Environment by the BIM for Aged Person - With Sanitary Facilities of Elderly Housing Facility - (노인 주거시설의 위생공간을 중심으로 고령자의 건강과 무장애 생활환경을 위한 인증 방법에 관한 연구 - BIM기반 설계 및 응용을 통한 방법을 중심으로 -)

  • Hong, Sa-Chul;Paik, Jin-Kyung;Kim, Suk-Tae
    • Korean Institute of Interior Design Journal
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    • v.26 no.3
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    • pp.13-24
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    • 2017
  • Promoting barrier-free living environments is necessary in residential facilities on which senior citizens rely most of their lives. Safety of elder people can be reassured by a certification system based on the existing barrier-free certification program in public facilities. The range of certification does not cover all living area, but is limited to the bathroom, which is a sanitary space. Given the nature of BIM modeling, an existing multi-family building was selected and modeled, as the certification process requires all the necessary information and various viewport. BIM modeling of the bathroom was conducted in accordance with the requirements of the certification for barrier-free living environment. The results suggested that there is a need for a removal of thresholds, larger doors, better selection of finishing materials, sufficient room for a wheelchair, larger space next to the toilet, and the availability of an emergency bell and grab bars. Such information supports the potentials of BIM modeling, and it is expected that an automated certification system would be established in the foreseeable future.

Improvement in Wind Vector from UHF Wind Profiler Radar through Removing Ground Echo (지형에코 제거를 통한 UHF 윈드프로파일러의 바람벡터 개선)

  • Kim, Kwang-Ho;Kim, Park-Sa;Kim, Min-Seong;Kang, Dong-Hwan;Kwon, Byung Hyuk
    • Journal of Environmental Science International
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    • v.25 no.2
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    • pp.267-280
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    • 2016
  • Ground echo is radar return from stationary targets such as buildings and trees. Wind vectors from the wind profile radar in Gangneung are affected by ground echoes due to the complex mountainous terrain located to the west and the south. These ground echoes make a spurious peak close to the direct current (DC) line signal in Doppler spectra. Wind vectors polluted by ground clutters were determined from spectra of oblique beams. After eliminated the terrain echoes, the accuracy of wind vector compared with radiosonde was improved about 68.4% and its relative coefficient was increased from 0.58 to 0.97.

A study on non-invasive SaO$_2$ measurement algorithm to improve on effect of the motion artifact (동잡음의 영향을 개선한 비관혈식 산소포화도 측정 알고리즘에 대한 연구)

  • 이준하
    • Progress in Medical Physics
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    • v.11 no.2
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    • pp.101-107
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    • 2000
  • Pulse oximetry is a non-invasive optical method which measures arterial oxygen saturation with two different wavelength. We can obtain the pulsating component of the arterial blood superimposed on DC level attenuated by venous blood, skin and other nonpulsatile components. This study is based on computing algorithm of oxygen saturation using the integral ratio of pulsatile components. In this algorithm, we used the half cycle of the pulsatile signal rely on arterial contraction. It's period is about 1/4 in 1 cycle. In the result, Our algorithm with 1/4 period of 1 cycle is similar to existing model. Because of removal that A part have low amplitude and possession in long term from calculating, the effect of the motion-artifact is decrease.

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Chest Wall Lipogranuloma after Hydrogel Implant Rupture: Case Report

  • Park, So Yoon;Han, Boo-Kyung;Cho, Eun Yoon;Bang, Sa-Ik
    • Investigative Magnetic Resonance Imaging
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    • v.19 no.3
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    • pp.191-195
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    • 2015
  • We present a 53-year-old woman with a large chest wall mass in the interpectoral space, which was eventually confirmed as a lipogranuloma resulting from hydrogel implant rupture. Ultrasonography (US) showed reduced implant volume with surrounding peri-implant fluid collection, suggesting the possibility of implant rupture. A heterogeneously hypoechoic mass was found between the pectoralis major and minor muscles adjacent to the ruptured implant. On magnetic resonance imaging (MRI), there was a large mass in the left interpectoral space of the upper inner chest wall. The mass showed slightly high signal intensity (SI) on pre-contrast T1-weighted image (WI) with mixed iso and high SI on T2-WI. The signal of the mass was suppressed using the water suppression technique but not with the fat suppression technique on T2-WI. The mass showed diffuse enhancement upon contrast enhancement. The enhancing kinetics showed persistent enhancement pattern. US-guided core needle biopsy revealed a lipogranuloma and removal confirmed a ruptured PIP hydrogel implant.

Experimental Study on the Hydroelastic Response of a Pontoon Type Structure with Nonuniform Mass and Stiffness (불균일 강성을 갖는 폰툰형 구조물의 유탄성 응답 특성에 관한 실험 연구)

  • Cho, Seok-Kyu;Hong, Sa-Young;Kim, Jin-Ha
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.5
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    • pp.34-40
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    • 2004
  • Very Large Floating Structure(VLFS) is regarded as one of promising candidates for the future utilization of ocean space. VLFS has the merits of small environmental effect. short construction term, easiness for extension and removal. It is well known that hydroelastic response is one of major design concerns of such a huge structure. Most of studies on the hydroelastic analysis of VLFS assumed uniform mass and bending stiffness. In case of a floating hotel where noticeable change of mass and stiffness at the hotel part is expected. it is necessary to investigate the effect of nonuniform mass and bending stiffness on the hydroelastic response. A model test of a pontoon type VLFS with nonuniform bending stiffness carried out for performance evaluation of a floating marina-hotel-convention center is described in this paper. Through investigation of model test results and comparison with numerical analysis using eigenfunction method, effect of the variation of bending stiffness is discussed.

A Case of Endobronchial Urokinase for Relief of Bronchial Obstruction by Blood Clots (좌측 주기관지 피덩이를 우로키나아제 기관내 국소주입으로 제거한 1예)

  • Choi, Jung;Lee, Sa Ra;Kwak, Choong Hwan;Pae, Hyun Hye
    • Tuberculosis and Respiratory Diseases
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    • v.55 no.3
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    • pp.297-302
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    • 2003
  • Background : Airway obstruction due to blood clot occurs unusually but in a variety of clinical settings. Initial efforts for removal of the endobronchial blood clot involve flexible bronchoscopic evaluation with saline lavage and suctioning and then forceps extraction. If unsuccessful, further options include rigid bronchoscopy, Fogarty catheter dislogement of the clot, and topical thrombolytic agents. The several successful uses of endobronchial streptokinase or urokinase to dissolve an endobronchial blood clot have been previously reported, but not yet in Korea. Herein we describe a 51-year old man with superior vena cava thrombosis secondary to Behcet's disease who experienced life threatening airway obstruction after hemoptysis due to a large organized blood clot in left main bronchus. Urokinase(260,000 U), injected through a fiberoptic bronchoscope, totally dissolved the clot. No complications occurred.

Microbial Desulfurization of a Bituminous Coal by Iron-Oxidizing Bacteria Thiobacillus ferooxidans (철산화 박테리아 Thiobacillus ferrooxidans에 의한 역청탄의 생물학적 탈황)

  • 류희욱
    • KSBB Journal
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    • v.11 no.2
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    • pp.238-245
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    • 1996
  • Microbial desulfurization characterlstics of a bituminous coal have been determined by using Thiobacillus ferrooxidans. The effects of process variables (such as coal pulp density, particle size and addition of surfactants) on pyrite removal have been investigated in both shake and airlift-bioreactor culture experiments. In shake experiments, pyrite could be removed over 78% for pulp densifies below 20% (w/v) and removed below 40% for pulp densities over 30% (w/v) in 8 days. Pyrite removal decreased with increasing pulp densities, and it also decreased sharply with increasing particle sizes. In airlift bioreactor experiments, pyrite at 50% (w/v) pulp density could be removed about 50%. Its value is much higher than 15% at the same pulp density in a shake experiment. With addition of surfactants, pyrite removal was enhanced in shake experiments significantly, whereas it was slightly decreased in an airlift bioreactor experiment.

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Efficiency of Apatite and Limestone in Removing Arsenic from Acid Rock Drainage at the Goro Abandoned Mine (인회석 및 석회석을 이용한 고로폐광산 ARD 내의 비소 저감효율 연구)

  • Park, Myung-Ho;Lee, Young-Woo;Hur, Yon-Kang;Park, Hae-Cheol;Sa, Sung-Oh;Choi, Jung-Chan
    • The Journal of Engineering Geology
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    • v.21 no.3
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    • pp.231-237
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    • 2011
  • An active apatite drainage system has been developed at the Goro abandoned mine, comprising a grit cell, a reaction cell, and a precipitation pond. Leachate from an abandoned adit and tailing ponds is collected in a pipeline and is transported to the apatite drainage system under the influence of the hydraulic gradient. The results of a laboratory experiment performed in 2004 indicate that the reaction cell requires 38.8 ton/year of apatite and that precipitate will have to be removed from the precipitation pond every 3 months. The purpose of this study is to evaluate a laboratory test on the efficiency of limestone and apatite in removing arsenic from ARD (acid rock drainage), and to evaluate the suitability of materials for use as a precipitant for the leachate treatment disposal system. The laboratory tests show that the arsenic removal ratios of limestone and apatite are 67.4%-98.3%, and the arsenic removal ratio of apatite is inversely proportional to its grain size. The arsenic compounds are assumed to be Johnbaumnite and Ca-arsenic hydrate. Therefore, apatite and phosphorous limestone can be used as a precipitant for the removal of arsenic, although it is difficult to remove arsenic from ARD when it occurs in low concentrations.