분출화염을 고려한 복수 구획의 간이 온도 예측 모델

강승구,박현우 한국화재소방학회 2024 한국화재소방학회 학술대회 논문집 Vol.2024 No.1

표면분석에 의한 유리 용기내의 백색현상 연구

강승구,이기강,김명석 한국결정성장학회 1996 韓國結晶成長學會誌 Vol.6 No.4

하절기에 장시간 창고에 보관된 일반 소다-라임-실리케이트 유리는 특별한 표면처리를 하지 않는 한 백색물질이 표면에 석출되는 weathering 현상이 나타날 수 있다. 본 연구는 유리병 내벽 표면에 생성된 백색물질을 습식법 및 표면분석법 등을 이용하여 분석하고 대기의 변화에 따른 weathering 정도를 연구하였다. 표면에 석출된 백색의 물질은 육각관상의 Na$_2$CO$_3$${\cdot}$H$_2$O와 CaCO$_3$로 규명되었다. 해안지방에서 제조-보관되었던 유리병 표면은 내륙지방의 유리병에 비해 weathering된 깊이가 3배 정도로 그 정도가 심하여 weathering이 대기중의 수분량에 크게 의존함을 알 수 있었다. It has been found that an white precipitates at the inside surface is a common characteristics of soda-lime-silica glasses which have not undergone special surface treatments during hot weather season. In this study, the white deposits were examed using by solution method, surface analysis etc., and the dependence of weathering on the atmospheric condition was also investigated. As a results, the white precipitates on the glass surface was discorved as carbonates like $Na_2CO_3{\cdot}H_2O,CaCO_3$. Coming to atmosphere-dependence, it was shown that the glass made and stored at sea shore province had 3 times much severe weathering than that at land province.

온도 및 광파장을 감지하는 스마트 복합재료에 관한 연구

강승구 한국결정성장학회 1996 韓國結晶成長學會誌 Vol.6 No.3

광투과성 BK10 glass fiber/PMMA 복합재료의 합성조건을 변화시켜 복합재료가 온도와 파장을 감지하는 센서로서의 응용 가능성이 있는지를 연구하였다. 유리섬유 제조시 뽑아내는 속도와 온도등의 공정조건에 따른 유리섬유의 직경 및 굴저율을 측정하였고 유리섬유에 코팅되는 coupling agent의 용매 및 코팅방법에 대하여 연구하였다. 복합재료의 최대광투과도를 나타내는 온도($T_{max%}$)는 복합재료에 강화되는 유리섬유의 크기(굴정율), 유리섬유 vol%, PMMA의 분자량등을 변화시키면 $13~50^{\circ}C$ 범위에서 조정될 수 있었으며, 측정파장을 변화시킬 경우 $T_{max%}$ 값이 $35~55^{\circ}C$ 범위가 되도록 합성하는 것이 가능하였다. 한편 복합재료를 파장의 함수로서 광투과도를 측정하였을 때 최대광투과도가 나타나는 파장($\lamda_{max%}$)은 나타나지 않았다. The possibility of application or the transparent BK10 glass fiber/PMMA composites as a temperature-or wavelength-sensors was studied. Measurement of diameter and refractive index for glass fibers to be reinforced to PMMA as a function of drawing speed and temperature was done and the appropriate coating methods and solvent for coupling agent was researched. $T_{max%}$ value at which the maximum transmission for the composites occurs could be controlled to be in $31~50^{\circ}C$ by the processing factors such as fiber diameter, fiber vol%, molecular wt. of PMMA. Furthermore, with different wavelength other than 589.3 nm, the $T_{max%}$ value could be controlled to be in $35~55^{\circ}C$. For the sensibility of wavelength for the composites, there was not a wavelength ($\lamda_{max%}$) showing maximum transmission.

광섬유 1차 Coating용 UV 경화수지의 제조 및 물성

강승구,하창식,김한도,Gang, Seung-Gu,Ha, Chang-Sik,Kim, Han-Do 한국섬유공학회 1991 한국섬유공학회지 Vol.28 No.11

Several urethane acrylate prepolymers were prepared from two different isocyanate, 4,4'-dicyclohexylmethane diisocyanate( HMDI) or isophrone diisocyanate(IPDI) , and two different polyol, polybutadienediol(PBD) and/or polypropylene oxide biol(PPG), and 2- hydroxyethyl acrylate(HEA) with dibutyl tin dilaurate as a catalyst. Formulation of the UV-curable buffer coating was made with prepolymer, photoinitiator, and one of four different diluent such as 1-vinyl -2-pyrrolidone(VP), lauryl methacrylate(LMA), acrylic acid -2-ethyl hexyl ester(AEHE) and acrylic acid n - butyl ester(ABE). The effect of the chemical structure of diluent and prepolymer, and overall composition of the prepolymer/diluent on the properties of IV-curable urethane acrylate for primary optical fiber coating were investigated. The properties of the polyurethane acrylate coating material such as modulils, refractive index, and viscosity were dependent on the type and content of prepolymer and diluent, and overall composition of the formulation. It was found that AEHE is desirable diluent for primary fiber coating material. The desirable composition of PBD, when mixed PBD/PPG dials are used, is about 50wt%. Most of the urethane acrylate prepolymers prepared in this study could be used for primary optical fiber coating material and exhibited good properties, i.e., low glass transition temperature, low modulus even at low temperature, say, below -40℃, high refractive index and low viscosity.

The Effect of Molecular Orientation on the Biodegradability in PCDA

강승구,유의상,임승순,최윤선,김동국 한국고분자학회 1997 한국고분자학회 학술대회 연구논문 초록집 Vol.1997 No.10

Poly ( ethylene 2,6- naphthalate ) ( PEN )

강승구,박상순,임승순 한국고분자학회 1996 한국고분자학회 학술대회 연구논문 초록집 Vol.1996 No.4

경표피 배출 소견을 보이는 선단 흑자성 모반 1예

강승구,양홍윤,김윤석,유희준,반재용 대한피부과학회 1999 大韓皮膚科學會誌 Vol.37 No.4

Pigmented lesions of palmar and plantar skin may cause diagnostic problems, because some features of benign lesions in these sites may raise the suspicion of melanoma if considered alone. Transepidermal elimlnation is a mechanism by which a substance is eliminated through the epidermis, and it is apt to be confused with a feature of melanoma that tumor cells are located at all layers of the epidermis. We report a case of transepidermal elimination of nevus cells in acral letiginous nevus which needs a differential dignosis of melanoma.

Cordierite계 결정화 유리의 특성에 미치는 다양한 첨가제의 영향 고찰

강승구,김용성 경기대학교 부설 산업기술종합연구소 2011 산업기술종합연구소 논문집 Vol.39 No.-

종결정법을 이용한 저전압 ZnO 배리스터의 제조 및 전기적 특성

강승구,오재희 한국세라믹학회 1988 한국세라믹학회지 Vol.25 No.5

ZnO low voltage varistor was obtained by varying a) the amount of seed grains, b) the size of seed grains, and c) sintering temperature. Also, the optimum condition for fabricating the ZnO seed grains was studied. Large ZnO seed grains were obtained by washing a ZnO sintered body containing 1m/of BaCO3 in boiling water. When the seed grains were added, abnormal grain growth occurred, and the varistor voltage sharply decreased. However, when more than 5w/o of seed grain content was added, the varistor voltage gradually increased. When 10w/o seed grains of 75~106${\mu}{\textrm}{m}$ were added and sintered for 2 hours at 1200 to 125$0^{\circ}C$, low voltage varistor properties with V1mA/mm of 19V/mm and nonlinear exponent ($\alpha$) of 12 occurred.

광섬유 2차 Coating용 UV 경화수지의 제조 및 물성

강승구,김한도 한국섬유공학회 1992 한국섬유공학회지 Vol.29 No.1

Studies have been carried out to investigate the effect of the chemical structure of reactive urethane acrylate prepolymers and diluents on the properties of the Uv - curable polyure-thane acrylates for secondary optical fiber coating. Several urethane acrylate prepolymers were prepared from 4,4'- dicyclohexylmethane diisocynate(HMDI) and butandiol(BD) /poly(ethylene butane adiphate diol)(SS)polyol and 2-hydroxyethyl acrylate(HEA) with dibutyl tin dilulate as a catalyst. The UV - curable secondary coating material for optical fiber was formulated from the prepolymer, photoinitiator and one of two different diluents such as tetraethyleneglycol diacrylate(TEGDA) and trimethylol propane triacrylate(TMPTA). By dynamic mechanical thermal analysis, the storage modulus of the coating material film was found to increase with increasing BD and TMPTA contents. The maximum tan 8 peak for the coating materials prepared in this study was in the range of 70 and 90˚C. The maximum tan 8 and loss modulus peaks shifted to higher temperature with increasing BD content. The tensile strength and modulus increased with the increase of the number of functional group of diluent. The higher strength and modulus are due to the high content of hard segment and crosshnking by multifunctional diluent, respecti-vely. The desirable BD content is in the range of 5Omol% % and 6Omol %, and TMPTA content is about 30wt % for secondary coating material of high modulus.