자매에서 발생한 두피의 만성 피부 홍반성 루푸스

강승구,이창우,정성수 ( Seung Goo Kang,Chang Woo Lee,Sung Soo Jung ) 대한피부과학회 1997 대한피부과학회지 Vol.35 No.6

Scalp involvements occur in 30-60% of patients with chronic cutaneous lupus erythematosus (CCLE), and may result in ii reversible cicartricial alopecia due to follicular destructions. The pathogenesis of CCLE is consiclered to be multifactorial;relevant factors would be immunogenetic, hormonal, and environmental ir fluences. Perhaps, the immunogenetic factors may be more impor- tant. We report a case of two sisters who had superficial scarring alopecia on the scalp, in the constitutions of underlying mixed connective tissue disease (MCTD) and undifferentiated connective tissue syndrome (UCTS), respectively. This sister-CCLE case is regarded to be the first report among familial CCLE in Korea. (Korean J Dermatol 1997;35(6): 1263-1267)

석탄 바닥재가 포함된 결정화 유리의 특성에 미치는 수식제의 영향

강승구,Kang, Seung-Gu 한국결정성장학회 2010 한국결정성장학회지 Vol.20 No.1

화력 발전소에서 배출된 석탄 바닥재로 L-A-S($Li_2O-Al_2O_3-SiO_2$)계 결정화 유리를 제조함에 있어 수식제인 CaO 첨가가 결정화 온도, 결정상 종류, 미세구조 등의 특성에 미치는 영향을 분석하였다. L-A-S계 유리에 CaO를 첨가하면 DTA 그래프 상의 유리 전이 온도 및 결정화 온도가 함께 높아지고 주 결정상으로 ${\beta}$-spodumene($LiAlSi_2O_6$) 및 eucryptite ($LiAlSiO_4$)가 생성되었으며, 동시에 CaO와 관련된 미지의 상도 약간 생성되었다. 결정화 유리 시편은 표면 및 내부 결정화 거동을 함께 나타냈으며, CaO 첨가량이 증가하면 시편 내부의 결정 크기 및 분율이 높아졌다. 또한 시편의 겉에서 내부 방향으로 성장한 표면 결정은, CaO 첨가에 따라 다양한 형태를 보였으며 CaO 첨가량이 9 wt% 이상이 되면 일부 균열이 관찰되었는데 이는 ${\beta}$-spodumene과 CaO 관련 결정 간에 열팽창계수 차이에 의한 것으로 생각된다. The influence of CaO addition on the crystallization temperature, crystal types, and microstructure of L-A-S ($Li_2O-Al_2O_3-SiO_2$) glass-ceramics system fabricated from a coal bottom ash, produced at thermal power plant, was studied. The glass transition and crystallization temperatures were shifted to the higher temperature position with increasing CaO content in a non-isothermal analysis using a DTA. The major crystalline phases of L-A-S glass-ceramics system produced were identified as ${\beta}$-spodumene ($LiAlSi_2O_6$) and eucryptite ($LiAlSiO_4$). The glass-ceramics showed a bulk and surface crystallization behavior at a time. With increasing CaO content, the ${\beta}$-spodumene peak in XRD increased and some CaO-related phases were formed. The surface crystal grown from the exterior to the center in glass-ceramics showed various shapes by amount of CaO added. Some cracks were generated at the glass-ceramics containing CaO above 9 wt% due to the mismatch of thermal expansion coefficients between a ${\beta}$-spodumene and CaO-related crystal phases.

수직형 유동층로에서 제조된 인공경량 세골재의 특성

강승구,Kang, Seung-Gu 한국결정성장학회 2009 한국결정성장학회지 Vol.19 No.1

기존의 로타리 킬른으로는 융착 현상 때문에 3 mm 이하 크기의 세골재를 제조하기 어려웠다. 이를 해결할 수 있는 수직형 유동층로를 설계, 제작하고 이로부터 점토 : 석분슬러지 :폐백토 =60 : 30 : 10(wt%)조성의 성형체를 소성하여 비중 $1.1{\sim}1.7$, 흡수율 $11{\sim}19%$의 다양한 특성을 갖는 경량 세골재를 제조하였다. 골재를 발포시키기 위한 최소 소성온도는 $1130^{\circ}C$이었다. $1140^{\circ}C$ 이상으로 소성된 시편은 전형적인 발포 경량골재 특성을 보였으며, 표면에 균열이 크게 벌어져서 내부 층이 드러나 보였다. 그러나 표면에 발생된 균열은 black core 내부로 진행되지 않았기 때문에 흡수율에 영향을 주지 않았다. 소성온도가 증가하면 골재의 shell 두께는 감소하고 black core 영역은 넓어졌으나 유지시간은 미세구조에 따른 영향을 주지 않았다. 소성온도가 증가되면 표면에 액상 발생량이 증가하여 골재의 흡수율은 감소하였다. 또한 소성시간도 골재 흡수율에 큰 영향을 주었는데, 이는 액상을 형성하고 또 생성된 액상이 표면의 개기공을 막아 폐기공으로 변화시키는데 시간이 필요하기 때문인 것으로 생각된다. It was difficult for the existing rotary kiln to fabricate the fine aggregates under 3 mm due to the sticking phenomenon between specimens. In this study, the vertical type fluidizing furnace was designed and manufactured by which the lightweight fine aggregates of specific gravity $1.1{\sim}1.7$, water absorption $11{\sim}19%$ could be fabricated from the green body of clay: stone sludge: spent bleaching clay = 60 : 30 : 10 (wt%) without sticking-together happening. The minimum sintering temperature for bloating of aggregates was $1130^{\circ}C$. The specimens sintered over $1140^{\circ}C$ showed the typical bloating characteristics of lightweight aggregates and an inner layer was discovered due to widened cracks on a surface. But the crack on a surface did not propagate into a black core area so had no effect on a water absorption of aggregates. The sintering temperature made the thickness of shell and the black core area thin and expanded respectively but the sintering time did not affect the microsturcture of aggregates. The water absorption of aggregates decreased with increasing temperature owing to increased amount of liquid formed on a surface. Also sintering time affected a lot on a water absorption because it takes a time to form a liquid, which change the open pores to closed pores by blocking.

석탄 바닥재-${Na_2}O-{Li_2O}$계 결정화 유리의 미세구조 분석

강승구,Kang, Seung-Gu 한국결정성장학회 2009 한국결정성장학회지 Vol.19 No.1

The glass-ceramics composed of coal bottom ash produced from a thermal power plant, $Na_{2}O$ and $Li_{2}O$ as a flux agent and $TiO_2$ as a nucleation agent were fabricated and its microstructures were analyzed. The nepheline was a major crystal phase in the glass-ceramics fabricated and its amount increased with $TiO_2$ addition. The glass-ceramics without $TiO_2$ addition had the thick surface crystals induced by a surface-crystallization mechanism and no crystal in the interior matrix. The surface crystallization, however, was restrained and the interior matrix was completely crystallized showing dendrite shape spread with fine particles < $1{\mu}m$ when added with $TiO_2$ above 4 wt%. For the glass-ceramics containing 6 wt% $TiO_2$, the $5{\mu}m$-long dendrite crystal; were interlocked each other which could suppress the crack propagation effectively at the external loading applied. 화력발전소로부터 발생된 석탄 바닥재(coal bottom ash)에 융제로 $Na_{2}O$ 및 $Li_{2}O$를, 핵 형성제로 $TiO_2$를 첨가하여 결정화유리를 제조한 뒤 그 미세구조를 분석하였다. 시편내 주결정상은 nepheline이었고, $TiO_2$가 첨가됨에 따라 nepheline 결정상 분율이 증가되었다. $TiO_2$가 첨가되지 않은 시편은 표면 결정화 기구에 수지(dendrite) 형태의 결정상이 성장되었으며, 내부 모상에는 결정이 거의 생성되지 않았다. 그러나 $TiO_2$ 첨가량이 4% 이상으로 증가되면, 표면결정화 기구는 억제되어 표면결정층의 두께가 얇아졌고 내부 모상은 결정질로 전이되었으며 동시에 $1{\mu}m$ 이하 크기의 미립자도 함께 생성되었다. 특히 6%의 $TiO_2$가 첨가된 결정화유리 내부에는 길이가 $5{\mu}m$인 수지상 결정들이 서로 얽혀진 형태를 보였으며, 이러한 미세구조는 외부로부터 하중을 가해졌을 때 발생되는 균열의 전파를 효과적으로 억제할 수 있을 것으로 예상된다.

슬립 공정으로 제조된 비산재-점토 계 소결체의 물성 및 기반재로의 적용특성

강승구,이영생,Kang, Seung-Gu,Lee, Yeong-Saeng 한국결정성장학회 2008 한국결정성장학회지 Vol.18 No.6

The civil engineering properties for the coal fly ash produced from a power plant mixed with sintered powders made from the fly ash-clay slip system were measured and its applicability for the foundation soils was investigated. The F-slip whose dispersion state is 'not good' and C-slip which is re-flocculated by adding a flocculant to a well-dispersed slip were fabricated and then sintered. The sintered body made from C-slip had more uniform microstructure than that of F-slip, therefore, the bulk density and compressive strength were improved. The civil engineering properties such as compression index, compressive strength, permeability coefficient of fly ash were improved by mixing $0.84{\sim}2\;mm$ powders obtained by crushing a sintered body made from C-slip. Therefore, the applicability of mixed powders composing of fly ash and sintered body made from C-slip was confirmed to foundation soils due to its improved civil engineering properties. 비산재-점토 계 슬립으로부터 제조된 소결체 분쇄 분말을 화력발전소에서 배출되는 비산재와 혼합하여 그 토목공학적 특성을 측정하고 기반재로의 적용가능성을 조사하였다. 분산이 잘 되지 않은 비산재-점토 계 슬립(F-slip)과 이를 분산 시킨 후 재응집시킨 슬립(C-slip)을 제조하고 이로부터 소성체를 합성하였다. C-slip으로부터 제조된 소결체가 F-slip 경우 보다 더 균일한 미세구조를 나타냈으며 따라서 그 밀도 및 강도가 더 높았다. C-slip으로 부터 소성된 소결체를 파쇄한 뒤 $0.84{\sim}2\;mm$ 입자를 추출하여 순수 비산재에 섞은 혼합분말은 압축지수, 압축강도 그리고 투수계수 등 토목공학적 물성이 순수 비산재에 비하여 향상되었다. 따라서 슬립 공정으로 제조된 분말을 비산재에 혼합하게 되면 그 역학적 특성이 개선되어 기반재 또는 기층재로의 적용 가능성이 향상됨을 확인하였다.

TiO₂ 하이브리드에 의한 바이오-폴리우레탄 멤브레인 필름의 투습성 향상에 관한 연구

강승구,강구,곽남호,진호진,홍성현,주일중,권오경,민병길,Kang, Seung-Gu,Kang, Goo,Kwak, Nam Ho,Jin, Hojin,Hong, Seong Hyun,Joo, Il Jung,Kwon, Oh Kyung,Min, Byung Gil 한국섬유공학회 2016 한국섬유공학회지 Vol.53 No.2

The aim of this work was to enhance the water vapor permeability of bio-polyurethane thin film, whose essential application is as a non-microporous type of film in breathable fabrics, by hybridizing it with nano- and micro-sized titania ($TiO_2$). The bio-polyurethanes were synthesized from 4,4-diphenylmethane diisocyanate (MDI) and a polyol mixture containing polyethylene glycol (PEG) and soybean oil-based polyol, that is, bio-glycols by the hydroxylation of soybean oils upto 25% by weight of bio-polyurethane. We studied the effect of hybridizing the bio-polyurethane films with hydrophilic nano- or micro-sized $TiO_2$ on their breathability by measuring the water contact angle and the water vapor permeability of the films; it was found to significantly enhance the permeability of the bio-polyurethane film. Further, nano-$TiO_2$ was more effective than micro-$TiO_2$ due to the higher surface area resulting from nano particles. On the other hand, it is expected that it would be possible to provide additive functionality to the bio-PU membranes due to photocatalytic effect of nano-$TiO_2$.

주차공간의 차량종류별 연소특성 DB구축을 위한 실험적 연구

강승구,김동은,서동구,김동준,김정희,권영진,Kang. Seung Goo,Kim. Dong Eun,Seo. Dong Goo,Kim. Dong Jun,Kim. Jeong-Hee,Kwon. Young Jin 한국방재학회 2014 한국방재학회논문집 Vol.14 No.1

주차공간 차량화재에 대한 열방출율의 모델화를 위해 중형승용차, 대형승용차, 승합차 3대의 차량을 선정하여 차량연소실험을 실시하였으며, 측정항목은 차량의 내외부온도, 열방출량, 질량감소량이다. 온도측정결과, 내화성능평가로서 적용되는 ISO 834곡선에 비해 높게 측정됨으로서, 내화성능의 검토가 필요할 것으로 사료된다. 또한, 차량의 총 발열량, 연소속도, 연소열 등 을 확보하였으며, 열방출율을 이용하여 차량별 열방출율의 모델화를 작성하였다. 그 결과 실험값과 모델값의 총 발열량의 오차범위는 10%내에 있었으며, 주차공간 구조물의 내화설계를 위한 차량종류별 연소특성 DB를 제시하였다. Car combustion experiment was conducted by selecting 3 cars, medium sedan, large sedan and van, for modeling of heat release rate(HRR) on car fire at parking space. Lists of measurement are internal and external temperature, HRR, mass decrement, and according to the result of experiment, it is considered that it requires review of fire resisting capacity of structure by temperature characteristic of internal and external temperature, and location of parking space structure. as a result review of fire resistance is needed. Also, Total HRR, burning speed, and heat of combustion of car were secured, and modeling of HRR for each car classification was written by using HRR. As a result, error range of total calorific value between experimental value and model value was within 10%, and it proposed combustion characteristic DB by car classification for fire resistance design of parking space structure.

다양한 성형법으로 제조된 인공 골재의 특성

강승구,Kang, Seung-Gu 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.1

The physical properties of artificial aggregates made from clay and inorganic wastes with poor plasticity depends largely on forming method. The artificial aggregates composing of coal fly ash, stone sludge and clay were fabricated using 4 different forming methods and those physical properties were comparatively analyzed. The surface of aggregates made through the extrusion forming process was dense and smooth but was rough for the aggregates obtained by crushing a tile-shaped green body. The aggregates made by pelletizing process had a weak green strength and bumpy surface. The shell generated at surface during a high temperature sintering process induced the most aggregates to be bloated due to a dense shell. But the aggregates made through pelletizing process with dense surface layer showed no significant change in bulk density with sintering temperatures. The water absorption of aggregates decreased with sintering temperature, and that of pelletized specimen was standing $1.8{\sim}2.2$ times higher than that of made by other forming methods. It is concluded that the aggregates having various properties could be fabricated from one batch by using different forming methods.

수직로에서 부유 소성된 경량 세골재의 특성

강승구,Kang, Seung-Gu 한국결정성장학회 2008 韓國結晶成長學會誌 Vol.18 No.6

입자를 부유 상태에서 소성할 수 있는 수직로를 이용하여 2 mm 이하 크기의 경량 세골재를 제조하고 그 물리적 특성을 고찰하였다. $1200{\sim}1300^{\circ}C$에서 소성된 대부분 시편은 표면에 다량의 액상이 발달하였고 따라서 내부의 가스가 팽창하여 다공성의 중앙부와 상대적으로 치밀한 표피층이 형성되었다. 특히 압출 성형체를 파쇄시켜 얻은 부정형의 C 계열 시편은 $1300^{\circ}C$ 이상으로 소결하면 내부에 가스가 팽창하여 시편 전체가 부풀어져서 구형으로 되었다. 본 부유 수직로에서 소성된 시편의 겉보기 비중은 $0.68{\sim}1.08$ 범위로 대부분 물에 뜰 정도의 경량이었다. 제조된 경량 세골재의 흡수율은 기공율과 비례하였고, 따라서 내부 기공들이 완전 고립된 폐쇄기공은 아님을 나타내었다. 부유소성로에서 제조된 세골재는 전기 머플로에서 소성된 시편과 비슷한 물성을 나타내었으나, 전기로에서 나타나는 골재 간 융착 현상이 발생하지 않았다. 수직로에서 부유소성된 세골재의 내충격성은 자연골재보다 다소 낮았으나, 단위용적중량은 KS 규격 기준을 만족하였다. The fine aggregates of below 2 mm size was fabricated using by the vertical furnace in which the aggregates could be sintered at floating state and its physical properties were analyzed. The liquid formed at the surface of specimens sintered at $1200{\sim}l300^{\circ}C$ induced a gas in core to expand so the denser shell and porous core could be produced. The C series specimen fabricated by crushing an extruded body had an irregular shape and sharp edges but those became spheroidized by bloating due to gas expansion inside. The fine aggregates fabricated in this study was as light as floating in the water and had an apparent density of $0.68{\sim}1.08$. The absorption rate was proportioned to a porosity showing that the pores in core was not closed completely. The properties of fine aggregates fabricated in vertical furnace were similar with those of in an electric muffle furnace but the sticking-together phenomenon by surface fusion was not occurred in the vertical furnace. The aggregates fabricated in this study had a little lower impact resistance than that of natural aggregate but satisfied the unit volume weight standard specified in KS.

인공경량골재의 표피층 구조가 흡수된 물의 방출속도에 미치는 영향

강승구,Kang, Seung-Gu 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.11

The artificial aggregates with dense surface layer (shell) was fabricated and the dependence of water emission rate upon the shell structures was studied. The EAF dust containing many flux components and waste white clay with ignition loss of above 48% were used as for liquid phase and gas forming agents during a sintering process respectively. In addition, the shell structure was modified with various processes and the modification effect on water emission rate was analyzed. The pores under $10{\mu}m$ were found in the sintered artificial light aggregates and disappeared by incorporating to a bigger pore during re-sintering. The water emission rate in an initial step depended on a void content of aggregates filled in a bottle rather than a shell structure. But, after 7 days where the water emission of the aggregate with a shell is above 40%, the shell of aggregates suppressed the water emission. The core of aggregates was exposed and most shell was lost when crushed to smaller size so, the ability for suppressing water emission of the crushed aggregates decreased. The activation energy for the water emission was $3.46{\pm}0.25{\times}10^{-1}$J/mol for the most specimens showing that the activation energy is irrelevant to the pore size distribution and shell structure.