• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.63-70
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• 2000

In 1925, H.J. Joosten was the first in the world to use chemical injection grouts composed of sodium silicate and calcium chloride. This unique development prompted the introduction of other chemical grouting techniques. Among these chemical grouting techniques, sodium silicate based grout has been the most widely used in the world, but it has not been generally considered to be a permanent material. Therefore, studies to improve the weak points of sodium silicate based grout have been conducted, and new applications of grout were recently developed. We also developed the micro fine hybrid silicate grout of suspention type which properties are sepecialized as the high strength and durability, according to the reactant of special sodium silicate grout and the high strength hardener. As the results of this study we could derive the 2 times over high strength of Micro fine hybrid Silicate grouting method(MS method) more than that of the ordinary sodium silicate grout. And also we could confirm that the alkali leakage of micro fine hybrid silicate grout is less than that of ordinary sodium silicate grout. So we could get the high strength and durability of hybrid silicate grout are superior to those of ordinary sodium silicate grout.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.241-242
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• 2019

This technology is a water leak repair technology using composite materials of concrete structures that block leakage of structures by injecting rapid microcement into the face of underground concrete to block water and injecting flexible glycidylacrylate. Rapid micro cement system repair materials are mixed with fine fibers to improve the flexural sensitivity of the material and to form a layer that blocks stabilized water at the back of the structure by allowing rapid and tight spatial filling during injection with high cohesion The glycidylacrylate repair material can control the expansion rate, and the external stress also has the characteristic that the form of the material is not destroyed or separated, which can also be applied to vibrating induced structures that produce repetitive fatigue loads, and has an effective durability in saline, alkali, acid (chloric acid, sulfuric acid, nitric acid).

• 한국지반환경공학회 논문집
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• 제2권1호
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• pp.67-79
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• 2001

본 연구는 최근 개발된 마이크로 복합실리카 그라우트재의 공학적 특성을 규명한 것으로서 연구에 사용된 그라우트재는 MSG-N(완결형)을 주로 사용하였으며, 화학성분, 입도분포, 광물특성을 분석하고 응결재인 특수규산과 보통시멘트에 대한 특성도 비교 분석하였다. 공학적 특성을 파악하기 위하여 블리딩시험, 전도시험, 응결시험, 육안관측, SEM촬영, 일축압축강도시험과 매립지에 대한 현장적용성 시험 등을 심사하였다. 이상과 같은 일련의 시험들에 의한 결과 일반적인 소디움 실리케이트 그라우트보다 마이크로 복합실리카 그라우트 공법(MSG공법)이 강도적인 측면에서는 2배정도 우수하고, 알카리 용출량이 현저하게 저하되었다. 특히 MSG공법에 의한 현장적용성 평가에 있어서 매립장 침출수 차단공법으로써 침투성이 우수하고 충분한 약액의 주입에 의해 상당한 투수계수 저감효과가 있음을 알 수 있었다.

• Journal of Chest Surgery
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• 제25권2호
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• pp.183-187
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• 1992

Reconstructive surgery for corrosive esophageal stricture was performed in 392 patients at National Medical Center from 1959 to 1990 Between Jan. 1971 and Dec. 1990, 23 cases were experienced stenotic anastoma of neck after reconstructive surgery for corrosive esophageal stricture. The major procedure of esophageal reconstruction was colon interposition without resection of the strictured esophagus except jejunal interposition in 1 case. There were 12 males % 11 females, and mean age was forty years. The caustic materials were 16[70%] alkali and 7[30%] acid. Half of the cases had hypopharyngeal injury. After reconstructed surgery, dysphagia was developed immediate in 65%, from 2 months to 5 months in 31%, and from years in 4%[1 case]. The complications were anastomatic leakage in 13 cases, anastomatic stenosis in 8 cases, graft gangrene in 1 case, and cancer development in 1 case. The therapeutic procedures were end-to-end anstomolis & partial resection of stenotic anastoma in 18 cases, bourgination in 2 cases, and coin interposition with graft removal in 3 cases. The therapeutic results were excellent in 16 cases, mild discomfort in 3 cases, poor in 3 cases, and death in 1 cases.

• 한국세라믹학회지
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• 제30권11호
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• pp.967-973
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• 1993

The effect on the hydration of cement was that Cu and Pb reacted with alkali to form soluble hydrates at theinitial stage and then there followed a slow reaction forming insoluble metal hydroxides. These hydroxides were deposited on the surface of cement particles providing a barrier against further hydration. But as a slow reaction continued, the insoluble layers were eventually destroyed and the hydration reaction resumed. Thereafter, another retardation occured by restricting the polymerization of silicates, shown by FT-IR spectroscopy analysis. In the case of Cr, as its reaction with cement caused H2O, the coordinator of Cr complex, to replace or polymerize with OH-, the formation of Cr complex promoted the leakage of OH- and increased the heat of dissolution. So the total heat evolution during hydration was larger than that in the case of Pb or Cu. The retarding effect of heavy metal ions was in the order Pb>Cu>Cr.

• Journal of Chest Surgery
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• 제28권11호
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• pp.1032-1037
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• 1995

Between September 1988 and December 1993, 32 cases of benign esophageal stricture, of which 12 males and 20 females, were managed in Seoul National University Hospital hospital. Their age ranged from 2 to 61 years, and the mean age was 33.9 years. The ingestion of caustic agent was the most common cause, and the caustic material was acid in 16 patients [58% and alkali in 11patients [39% . Nearly all of the patients complained of dysphagia, and some of chest pain, epigastric pain, weight loss, vomiting, general malaise, and dyspnea. The most frequent site of stricture was found in the upper thoracic esophagus with 34% incidence followed by the lower thoracic esophagus[28% , whole esophagus[19% , and the mid esophagus[16% . The operations performed were 17[53% ECG[esophagocologastrostomy , 5[16% PCG[pharyngocologastrostomy , 5[16% EG[esophagogastrostomy , 2 EJG [esophagojejunogastrostormy by free jejunal graft , and 1 case each of EJ [esophagojejunostomy , esophageal end to end anastomosis, jejunostomy only, and gastrostomy only. In 23 patients [72% , diseased esophaguses were resected, using transhiatal total esophagectomy in 15 [47% and transthoracic partial esophagectomy in 8 [25% . Of those 23 patients, 3 patients [9.4% were diagnosed as esophageal carsinoma on microscopic examination. The postoperative most common complications were unilateral vocal cord palsy in 6 patients [19% , followed by cervical anastomosis leakage in 4 patients [12.5% , wound infection in 2 patients [6% , and pneumothorax in 2 patients [6% . Late death occurred 8 months after the operation in one patient, which was associated with infection due to anastomotic leakage. Our experience shows that the rate of mortality and the morbidity were low in patients receiving surgical management for esophageal stricture and that the cancer transformation rate was high. We recommend esophageal reconstruction surgery with esophagectomy [transhiatal or transthoracic for the esophageal stricture because it can avoid a chance of prevent cancer transformation.

• 한국전기전자재료학회논문지
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• 제33권5호
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• pp.367-372
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• 2020

As packaging processes for atomic gyroscope vapor cells, the glass tube tip-off process, anodic bonding, and paste sealing have been widely studied. However, there are stability issues in the alkali metal which are caused by impurity elements and leakage during high-temperature processes. In this study, we investigated the applicability of a vapor cell low-temperature packaging process by depositing Au on a Pyrex cell in addition to forming an Au-Sn thin film on a cap to cover the cell, followed by laser irradiation of the Au/Au-Sn interface. The mechanism of the thin film bonding was evaluated by XRD, while the packaging reliability of an Ne gas-filled vapor cell was characterized by variation of plasma discharge behavior with time. Furthermore, we confirmed that the Rb alkaline metal inside the vapor cell showed no color change, indicating no oxidation occurred during the process.

• 한국광물학회지
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• 제21권3호
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• pp.239-246
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• 2008

강원도 영월 및 경북 봉화의 견운모광상은 화강암질 마그마의 알카리치환작용에 의한 광상으로 추정된다. 견운모광체는 캠브리아-트라이아기에 관입한 안주상의 우백질 화강암체 내에 배태되어 있으며, 이들 암주는 각기 시대미상의 페그마타이트질 미그마타이트와 선캠브리아기의 홍제사화강 암류를 관입하고 있다. 고생대 최하부층인 장산규암층은 열수작용 중에 그 방출을 막는 덮개역할을 하였으며, 견운모광상은 태백지향사 형성시에 생성된 함백향사의 남단 및 남동단에 각기 위치한다. 우백질 화강암류는 전기석을 가지는 페마타이트를 흔히 포함하며, 대체적으로 K 및 Na-장석류가 풍부하며, 광체는 암체의 상부 및 가장자리로 가면서 흔히 확인되며, 고품위광체는 거의 순수한 견운모 단일광물로 구성되는 초그라이젠화를 나타내기도 한다. 화학분석에 의하면, $Na_{2}O$ 및 $K_{2}O$함량이 $2.00\sim7.03wt%$로서 그라이젠화가 뚜렷하지만 CaO는 $0.05\sim4.51wt%$로서 알비타이트화는 미약하다. 영월 지역은 견운모와 함께 납석이 포함되므로 대현지역에 비하여 열수의 온도 등이 더 높았음을 암시한다. 태백산지역에는 그라이젠형광상으로 석석이 산출되었었고, 광상형성에 유리한 탄산염암의 분포가 넓으므로 중석, 휘수연 등의 감속원소와 함께 Be, Nb, Li 및 희토류원소류 등의 산출이 기대되며 이들에 대한 연구가 기대된다.

• 한국세라믹학회지
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• 제39권5호
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• pp.511-516
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• 2002

$Y(NO_3)_3{\cdot}5H_2O$ 과 $Mn(CH_3CO_2)_2{\cdot}4H_2O$를 출발물질로 하여 졸-겔(sol-gel)법으로 Si(100) 기판위에 육방정계의 $YMnO_3$ 박막을 제조하였다. $YMnO_3$ 박막의 열처리 온도변화, 가수분해시 가수의 양(Rw)과 촉매제의 첨가에 따른 결정 구조 및 전기적 특성을 조사하였다. $YMnO_3$ 박막의 결정화는 700${\circ}C$부터 시작되었고 완전한 결정화는 800${\circ}C$-1시간 열처리하여 이루어 졌으며, $YMnO_3$ 박막의 가수의 양 Rw=6일때 육방정계 $YMnO_3$상의 c-축 (0001) 우선 배향성을 나타내었고, Rw=1 과 Rw=12인 경우에는 Rw=6인 경우보다 c-축 배향성은 감소하였다. 산성이나 염기성 촉매제 첨가에 따라 $YMnO_3$ 박막의 결정성 및 우선 배향성은 영향을 받아 c-축 우선 배향성은 감소하고 사방정계의 $YMnO_3$ 상을 형성하였다. Rw=6일 때 $YMnO_3$박막은 0.2V인가 전압에서 $1.2{\times}10-8 A/cm^2$으로 우수한 누설 전류 밀도를 나타내었고 누설 전류 밀도는 인가 전압에 따라 크게 변하지 않았다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권4호
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• pp.260-264
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• 2013

Calcium hydroxide root canal filing paste (vitapex) is widely used as canal filling paste for infected canal. However, chemical burn is possible because of the high alkali base of calcium hydroxide. A 57-year old woman was admitted to our clinic for consistent dull pain and paresthesia in the left upper lip, zygoma and buccal cheek area, which developed during an endodontic treatment of the left lateral incisor. Radiographic finding showed radiopaque material, which exits from the left incisor root apex, and was within the left canine and first premolar buccal soft tissue. The overfilled Vitapex extended to the soft tissue was surgically curetted. The result of the surgical curettage was favorable. Though slight hypoesthesia on the upper lip was still remained, paresthesia on zygomatic and buccal cheek area was completely recovered. As far as we know, this is the first case report of infraorbital nerve damage from overfilled Vitapex material.