• 한국결정학회지
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• 제16권1호
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• pp.43-53
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• 2005

알칸화합물(alkanes)에서 탄소-수소결합을 활성화시켜서 더욱 값이 비싸고 더 유용한 알켄화합물(alkenes)로 만들 수 있는 촉매를 만들고자 지난 수 십 년간 많은 화학자들이 연구해왔다 이러한 목적의 하나로서 두개의 수소를 가지는 이리디움 P-C-P핀서(pincer) 착물 $(IrH_2{C_6H_3-2,6-(CH_2PBu_2^t)_2})$을 성공적으로 합성하였다. 이 착물은 알칸의 탈수소화반응(dehyrogenation)에 아주 효과적인 촉매로 알려졌다 알칸의 탈수소화반응에 촉매독으로 작용하는 질소, 물, 이산화탄소 및 일산화탄소와 같은 작은 화합물들과 직접 반응시켜서 어떻게 촉매독으로 작용하는지를 알아봤다. 촉매독으로 작용할 수 있는 화합물들을 합성하여 핵자기공명분광법(NMR)과 적외선분광법(IR)으로 확인하였고 분자구조를 알아보기 위해서 단결정X-ray 회절법을 통하여 확인하였다. 본 논문에서는 촉매 및 촉매독물질의 합성과 분자구조와 각각의 화합물의 반응성과 특이성을 알아보았다.

• 자원리싸이클링
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• 제13권5호
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• pp.45-50
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• 2004

탄화철을 합성하는 공정을 수소($H_2$) 환원과 $CO-H_2$ 혼합가스에 의한 탄화의 2단계 과정으로 나누어서 수행했다. 환원종료 후 미량의 암모니아 가스를 첨가하여 환원철의 표면을 개질한 후, 탄화시간 경과별 탄화상태를 C/S 분석기(Low C/S determinator), 뫼스바우어 분광 분석기(Mossbauer spectroscopy), XRD(X-ray diffraction patterns), SEM(Scanning electron microscopy), TEM(Transmission electron microscopy), XPS(Photoelectron spectroscopy), 및 라만분광기 (Raman spectroscopy)를 사용하여 조사하였다. 연구결과, 미량의 암모니아가스로 환원철 표면을 개질함으로써 탄화철의 분해 및 유리탄소의 석출을 방지할 수 있을 뿐만아니라 6.68wt% 이상 10wt% 까지 탄소가 과고용된 상태에서도 분해되거나 유리탄소를 석출하지 않고 안정상태를 유지하였다. 이러한 결과로부터 철(Fe)과 세멘타이트(cementite, $Fe_3C$)가 혼합되지 않고 고탄화철(SIC, super iron carbide)인 Fe5C2 상태의 안정한 단일상을 얻는데 성공하였다.

• 한국한의학연구원논문집
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• 제1권1호
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• pp.1-14
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• 1995

The clinical study was carried out on 1737 cases of inpatient and outpatient which have been diagnosed as C.V.A at hospital attached to 8 colleges of oriental medicine in Korea or National Medical Center from January 1st 1994 to December 31st 1994. The results were as follows; 1. In this study, the case of Occlusive C.V.D was 70.1%, Cerebral hemorrhage was 20.5%, Transient ischemic attack (T.I.A) was 5.3%, Subdural hemorrhage was 3.0%, Subarachnoid hemorrhage was 0.8% 2. It was confirmed by C.T (20%), E.K.G. (19%), X-ray (19%), Urinalysis (19%), Hematoscopy (20%). 3. The mean days of hospital treatment was 27.88 days, mean days of ambulation was 70.34 days. The mean days of hospital treatment of Occlusive C.V.D, Cerebral hemorrhage, T.I.A., Subdural hemorrhage, Subarachnoid hemorrhage were 25.79, 39.32, 12.49, 16.23, 23.40 days, respectively. The mean days of ambulation of Occlusive C.V.D, Cerbral hemorrhage, T.I.A., Subdural hemorrhage, Subarachnoid hemorrhage were 74.40, 93.68, 69.10, 29.75, 32.57 days, respectavely. 4. Oriental medical treatment of C.V.A was mainly Acupuncture (25%), Paper of Chinese herbs (22%), Chinese physiotherapy (14%), Extract of Chinese herbs (11%). 5. Oriental medical physiotherapy for C.V.A was mostly E.S.T., Kinesiatrics, electric negative therapy, others Aerohydrotherapy, interferential current therapy (I.C.T.), Carbon, Samhogi, T.E.N.S., Ultra-sound, Infra-red, Microwave, T.D.P., Ultraviolet, S.S.P., Chinese herbs beth, Prarffin bath, Magnetic treatment and tractions.

• Korean Chemical Engineering Research
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• 제43권3호
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• pp.401-406
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• 2005

본 연구에서는 다중벽 탄소나노튜브의 화학적 표면처리가 에폭시 매트릭스 복합재료의 유리전이온도, 열안정성 그리고 동적 점탄성거동에 미치는 영향을 고찰하기 위하여 시차주사열량계(DSC), 열중량분석기(TGA) 그리고 동적 기계적 분석기(DMA)를 통하여 각각 측정하였다. 탄소나노튜브의 표면처리는 35 wt％의 $H_3PO_4$(A-MWNTs) 혹은 35 wt％ KOH(B-MWNTs) 용액으로 화학적 표면처리를 하였으며, 표면처리 후 표면특성 변화는 pH, 표면 산 및 염기도, 적외선 분광법(FT-IR)과 자외선 광전자 스펙트럼(XPS) 분석을 통하여 알아보았다. 그 결과로서, 산-염기 상호반응에 의한 각각의 표면처리는 탄소나노튜브의 표면특성 및 화학적 조성 변화를 가져오며, 산처리한 MWNTs/에폭시 복합재료의 경우가 염기처리 및 미처리 시편과 비교하여 열안정성 및 동적 점탄성 특성에 있어서 탄소나노튜브 표면에 도입된 산성 관능기 그룹의 영향으로 큰 값을 나타내었다. 이는 염기성을 가지는 에폭시 수지와 산성을 가지는 탄소나노튜브와의 산-염기 및 수소결합에 의한 계면결합력의 향상 때문이라 생각된다.

• The Journal of Advanced Prosthodontics
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• 제8권4호
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• pp.275-284
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• 2016

PURPOSE. The aim of this study was to evaluate the influence of different surface treatment methods on the microtensile bond strength of resin cement to resin nanoceramic (RNC). MATERIALS AND METHODS. RNC onlays (Lava Ultimate) (n=30) were treated using air abrasion with and without a universal adhesive, or HF etching followed by a universal adhesive with and without a silane coupling agent, or tribological silica coating with and without a universal adhesive, and divided into 6 groups. Onlays were luted with resin cement to dentin surfaces. A microtensile bond strength test was performed and evaluated by one-way ANOVA and Tukey HSD test (${\alpha}$=.05). A nanoscratch test, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy were used for micromorphologic analysis (${\alpha}$=.05). The roughness and elemental proportion were evaluated by Kruskal-Wallis test and Mann-Whitney U test. RESULTS. Tribological silica coating showed the highest roughness, followed by air abrasion and HF etching. After HF etching, the RNC surface presented a decrease in oxygen, silicon, and zirconium ratio with increasing carbon ratio. Air abrasion with universal adhesive showed the highest bond strength followed by tribological silica coating with universal adhesive. HF etching with universal adhesive showed the lowest bond strength. CONCLUSION. An improved understanding of the effect of surface treatment of RNC could enhance the durability of resin bonding when used for indirect restorations. When using RNC for restoration, effective and systemic surface roughening methods and an appropriate adhesive are required.

• 한방안이비인후피부과학회지
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• 제15권1호
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• pp.140-150
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• 2002

Introduction: Atopic dermatitis is chronic eczematous dermatosis which is related strongly to a family history of atopic disease and hereditary disposition. Its threshold of itching is low so that severe itching occurs and causes secondary eczema. Adult atopic dermatitis has mostly severe symptoms and progresses to chronic relapsing. Objective: The purpose of this study was to estimate the efficacy of oriental medical treatment and management on chronic adult atopic dermatitis. Subject: We studied 3 patients who visited Dongguk University Gangnam Oriental Hospital Dept. of Dermatol. with chronic adult atopic dermatitis from August 2001 to April 2002 and were observed for over 4 months. Methods: We treated them with herb-medication, acupuncture, negative therapy, aroma therapy, full spectrum visible ray therapy(by carbon arc) and external application(Jaun-go). We used the SCORAD index to assess the severity of atopic dermatitis. Results: There were 3 patients with chronic adult atopic dermatitis we could check for over 4 months by clinical scoring using the SCORAD system. 1. The grades of the severity of atopic dermatitis were lower only by the oriental medical treatments and management. 2. Intensities of relapse cases were lower then before the oriental medical treatments. 3. The secondary treatment term for relapse cases was shorter then the first treatment term after oriental remedies were used. Conclusion: Considering the above results, more study is needed on the chronic relapse cases with adult atopic dermatitis, the factors of increasing seventy of adult atopic dermatitis, the prognostic factors of adult atopic dermatitis, and the clinical interchange of chronic adult atopic dermatitis between oriental medicine and western medicine.

• 한국세라믹학회지
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• 제50권4호
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• pp.251-256
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• 2013

Multiwalled carbon nanotubes (MWCNTs) modified with Pd and $TiO_2$ composite catalysts were synthesized by the sol-gel method followed by solvothermal treatment at low temperature. The chemical composition and surface structure were characterized by X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Photocatalytic recycle degradation experiments were carried out under both UV and visible light irradiation in the presence of MWCNT/$TiO_2$ and Pd-MWCNT/$TiO_2$ composites. As expected, the nanosized Pd-MWCNT/$TiO_2$ photocatalysts had enhanced activity over the non Pd treated MWCNT/$TiO_2$ material in the degradation of a rhodamine B (Rh.B) solution. An increase in photocatalytic activity was observed and attributed to an increase in the photo-absorption effect by MWCNTs and the cooperative effect of Pd and $TiO_2$ nanoparticles. According to the recycled results, the as-prepared Pd-MWCNT/$TiO_2$ sample had a good effect on it.

• 한국재료학회지
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• 제2권1호
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• pp.35-42
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• 1992

실릴콘 산화막을 $CHF_3/C_2F_6$ 혼합가스를 사용하여 반응성이온 건식식각을 행할 때 실리콘 표면에 형성되는 잔류막과 손상충의 열적 거동을 X-선 광전자 분광기(XPS)와 이차이온 질량 분석기 (SIMS)를 사용, 연구하였다. 저항가열을 통한 in-situ 분석에 의해 폴리머 잔류막은 $200^{\circ}C$부터 분해가 시작되고 $400^{\circ}C$ 이상의 가열에서는 graphite 형태의 탄소 결합체를 형성하며 분해됨을 알았다. 질소 분위기하의 급속 열처리를 통해 잔류막의 열분해는 $800^{\circ}C$ 이상에서 완료되고 손상층을 형성하는 침투 불순원소의 기판 외부로의 확산이 관찰되었다.

• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2004년도 제20회 발표논문집
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• pp.33-42
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• 2004

The forged iron axe found in the No. 2 wood-framed tomb (the middle 3rd century) of Hwangseongdong, Gyeongju is rectangular on the plane level. It shows an obtuse angle in the edge part, while the joint part has the both sides folded up and shows the traces of wood. Under the reflected light, the Iron axe shines in metal luster, which is bright light gray or light creamy colors. The result of x-ray diffraction analysis shows that the axe consists of magnetite and geothite, which can explain why the composition and structure of the original ore has been kept intact. The microtexture of the axe has the irregular network of ferrite and pearlite, and tile cementite of tiny amount in the ferrite background. The overall treatment of the texture seems to be thermal with a high ratio of carbon. There are fine-grained magnetite, wolframite, quartz, calcite, mica, hornblende and pyroxene inside the axe. Those must be the impurities that they failed to remove in the refining process. The normal ferrite is composed of pure iron whose $Fe_2O_3$ proportion is from 99.16 to $99.84\;wt.\%$. Other than them, the ferrite parts usually contain $Al_2O_3\;and\;SiO_2$. The irregular network of pearlite also contains Impurities including $Al_2O_3\;and\;SiO_2$ and shows highly diverse patterns of carbon content. It's because the axe was carburized after the material was made to resemble pure iron. The decarbonization work didn't go well along the process marks. It's estimated that the original ore was bloom produced in low-temperature reduction and formed around in $727^{\circ}C$, which is eutetic temperature.

• Elastomers and Composites
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• 제44권3호
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• pp.290-298
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• 2009

본 논문에서 Fe-활성탄소 섬유(ACF)/$TiO_2$ 복합체 광촉매를 졸-겔 방법에 의하여 제조하였다. 합성된 광촉매는 UV조사하에서 MB용액의 광분해에 사용되었다. BET 데이터는 Fe와 Ti의 여러 가지 농도를 가지고 처리된 ACF의 표면에서 흡착 특성을 보여준다. SEM 사진에서 보여지는 것처럼, 철 혼합물과 $TiO_2$는 ACF 표면에 활착되어 있음을 나타내었다. X선 분말 회절법으로부터 얻어진 결과는 복합체로부터 FeO+$TiO_2$, Anatase 및 Rutile 구조의 결정상을 나타내었다. 원소분석을 위한 EDX spectra는 Fe와 함께 C, O, Ti의 peak들이 존재함을 나타내었다. MB 분해에 대한 활성은 $TiO_2$의 광분해와 Fe의 photo-Fenton 효과로 인해 전자/hole쌍 반응으로부터 파생된 -OH 라디칼들에 의한 것으로 여겨진다.