Aluminum salt 로부터 제조된 Alumina sol 의 점도와 방사성

송기창,강용 ( Ki Chang Song,Yong Kang ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.1

불안정성 대퇴골 전자간 골절에서 전자부 안정화 금속판 사용 후 발생한 고정실패

강수용(Soo Yong Kang),이은우(Eun Woo Lee),강기서(Ki Ser Kang),송광섭(Kwang Sup Song),이상학(Sang Hak Lee),박영욱(Young Uk Park),장승환(Seung Hwan Chang) 대한정형외과학회 2006 대한정형외과학회지 Vol.41 No.1

불안정성 대퇴골 전자간 골절에서 활강 고나사와 전자부 안정화 금속판(TSP)을 사용한 후에 생긴 고정실패의 기전은 발표된 보고가 거의 없다. 본 저자는 불안정성 대퇴골 전자간 골절에서 TSP를 사용하여 고정한 환자들 중 3예에서 발생한 금속파절을 보고하고자 한다. 이들 3예는 모두 같은 양상의 고정실패의 기전을 보이고 있으며 이는 금속판과 나사못의 연결부에서 생긴 피로골절의 양상을 나타내고 있다. 이들 중 2예는 불유합이 관찰되었고 1예는 골유합 4년 후에 우연히 발견되었다. 함께 시행한 생역학적 분석에서는 외측 피질골의 지지대역할을 해주는 TSP가 원위부 나사못에 전단력을 증가시켜 피로골절에 이르게 하는 것으로 분석되었다. 또한 파절된 나사못 표면에 대한 주사전자현미경(SEM) 사진은 금속파절이 적은 힘이 반복적으로 가해져서 생긴 피로골절임을 말해주었다. 이런 피로골절을 예방하기 위해 내고정물(TSP)의 개량과 수술술기의 개선이 필요할 것으로 보인다. There are few reports of the failure mode of a dynamic hip screw with a trochanteric stabilizing plate (TSP) in the treatment of unstable proximal femur fractures. We present 3 cases of fixation failure of a TSP used to treat unstable intertrochanteric fractures. All cases had the same type of failure mode, which represented a fatigue fracture of the distal screw at the junction of a plate and screw. Non-union occurred in 2 cases, and one case was an incidental finding 4 years after union. Biomechanical analysis and SEM (scanning electron micrograph) examination was also performed. Adding TSP to the plate might increase the level of shear stress and slip motion in the distal screw followed by a fatigue fracture. SEM of the surface of the broken screw revealed a multiple cycle and low stress fatigue fracture. Recommendations are made regarding the implant design and surgical technique.

Hydroxyethyl Methacrylate와 Methyl Methacrylate의 첨가량 변화가 수분산 폴리우레탄-아크릴 혼성 용액의 물성에 미치는 영향

김병석 ( Byung Suk Kim ),유병원 ( Byung Won Yoo ),이명구 ( Myung Goo Lee ),변태강 ( Tae Gang Byun ),송기창 ( Ki Chang Song ) 한국화학공학회 2012 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.50 No.4

Waterborne polyurethane dispersions (PUD) were synthesized from isophorone diisocyanate (IPDI), polycarbonate diol (PCD) and dimethylol propionic acid (DMPA) as starting materials. Subsequently, waterborne polyurethane- acrylic hybrid solutions were prepared by reacting the PUD with different amounts of the mixture of acrylate monomers, HEMA (2-hydroxyethyl methacrylate) and MMA (methyl methacrylate). As a result, the average particle size of waterborne polyurethane-acrylic hybrid solutions was increased with increasing the addition amounts of acrylate monomers. Also, the prepared coating films from waterborne polyurethane-acrylic hybrid solutions showed better abrasion resistance and chemical resistance than those of pure PUD.

Aniline Terminated Waterborne Polyurethane과 PEDOT/PSS의 블렌딩에 의한 대전방지 코팅용액의 제조

홍민기 ( Min Gi Hong ),허우영 ( Woo Young Huh ),변태강 ( Tae Gang Byun ),송기창 ( Ki Chang Song ) 한국화학공학회 2012 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.50 No.4

Polyurethane prepolymers were prepared from poly (carbonate diol), isophrone diisocyanate and dimethylol propionic acid. Then, aniline terminated waterborne polyurethane dispersion (ATPUD) was synthesized by capping the NCO group of the prepolymer with aniline monomer. Subsequently, ATPUD and waterborne polyurethane dispersion (PUD), respectively, were blended with conducting polymer, poly (3,4-ethylenedioxythiophene)/polystyrene sulfonate [PEDOT/PSS], to yield antistatic coating solutions, and the mixture was coated on the polycarbonate substrates. At adequate addition amounts of PEDOT/PSS less than or equal to 2.5 g, the surface resistances (1.0×1011~2.5×108 Ω/ cm2) of coating films from ATPUD showed better electronic conductivities than those (5.0×1011~6.3×109 Ω/cm2) from PUD. However, at excess amount of PEDOT/PSS of 3.0 g, the surface resistance from ATPUD showed similar electronic conductivity with that from PUD.

Aminopropyl Triethoxysilane과 아크릴 단량체를 이용한 Silylated Acrylic Polyurethane Dispersion의 제조

김병석 ( Byung Suk Kim ),윤동구 ( Dong Gu Yun ),유병원 ( Byung Won Yoo ),이명구 ( Myung Goo Lee ),변태강 ( Tae Gang Byun ),송기창 ( Ki Chang Song ) 한국화학공학회 2012 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.50 No.4

Waterborne polyurethane dispersion (PUD) was synthesized by capping the NCO groups of polyurethane prepolymers, prepared from isophorone diisocyanate, polycarbonate diol and dimethylol propionic acid, with aminopropyl triethoxysilane (APS), Subsequently, silylated acrylic polyurethane dispersion was synthesized by reacting the PUD with the mixture of acrylate monomers, 2-hydroxyethyl methacrylate and methyl methacrylate, The average particle size of silylated acrylic polyurethane dispersion, measured by the dynamic light scattering method, was increased from 39.0 nm to 399.8 nm by increasing the addition amounts of APS. Also, the pencil hardness of coating films of silylated acrylic polyurethane dispersion was enhanced from B grade to F grade with increasing APS content.

Sol-Gel 법에 의한 구형 , 단분산 alumina 분말의 제조

강용,송기창 한국화학공학회 1997 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.35 No.6

n-Octanol과 acetonitrile로 구성되어 있는 혼합용매 중에서 aluminum sec-butoxide(ASB)를 가수분해함에 의해 서브마이크론 크기의 단분산, 구형 alumina분말을 제조할 수 있었다. 이 과정 중 분말의 평균입경, 입도편차, 형상 등에 미치는 여러 실험변수들의 영향을 조사하였다. ASB농도가 증가함에 따라 병균입성 및 입도편차는 커지는 경향을 보였다. 반면에 물량의 증가는 평균입경 및 입도편차를 감소시켰다. 제조된 분말은 비정질상을 보였고, 1,000℃에서 2시간 열처리후 α-alumina로 상전이 되었다. Monodispersed, spherical alumina powders with submicrometer size were prepared by the controlled hydrolysis of aluminum sec-butoxide(ASB) in a mixed solvent consisting of n-octanol and acetonitrile. The effects of various experimental variables on average particle size, particle size deviation and morphology were investigated. As ASB concentration increased, the average particle size and particle size deviation increased. On the other hand, the increase of water concentration decreased the average particle size and particle size deviation. Prepared powder showed an amorphous phase. It transformed to α-alumina by heat treatment at 1,000℃ for 2 hrs.

Sol-Gel 법에 의한 방사성 Aluminurn Sol 의 합성과 섬유제조

강용,송기창,심정섭,홍원길 한국화학공학회 1997 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.35 No.1

AlCl₃-Al powder-H₂O계 용액을 출발물질로 하여 Sol-Gel법에 의해 alumina섬유를 제조하였다. Alumina sol의 방사성은 Al분말의 용해량에 의해 결정되며, Al powder/AlCl₃몰비가 3에서 5인 점성용액으로부터 겔섬유출 얻을 수 있었다. 이때 점성용액으로부터의 섬유의 인상은 350-3000p의 고점도 영역에서 가능하였다. 이렇게 얻어진 겔섬유를 1000℃에서 2시간 동안 열처리함에 의해 α-Al₂O₃섬유를 제조할 수 있었다. Alumina fibers were prepared by the sol-gel process from AlCl₃-Al powder-H₂O solution as a starting material. The spinnability of alumina sols was determined by the dissolved content of aluminum powders and gel fibers could be obtained from viscous solutions in a composition range of Al powder/AlCl₃ molar ratios of 3 to 5. Fiber drawing from the viscous solutions was possible in a high viscosity range of 350-3000 p. α-Al₂O₃ fibers were formed by calcination of the gel fibers at 1000 ℃ for 2 hr.

발열을 동반한 호중구감소증에서 Cefepime 단독투여와 Ceftazidime 및 Tobramycin 병합투여의 효능비교

정현욱,채제욱,강미라,양정채,문치숙,기현균,장현하,오원섭,김기현,백경란,이남용,송재훈 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내에서 발열을 동반한 호중구감소증이 있는 악성 종양환자에게 경험적 항생제로 베타락탐계 항생제와 아미노배당체의 병합요법의 사용이 일반적이다. Cefepime은 광범위 항균 작용을 가지고 있어, 그람 음성균 뿐만 아니라 그람 양성균에 대해서도 우수한 효과를 나타낸다. 재료 및 방법: 발열을 동반한 호중구감소증이 있는 악성 종양환자를 대상으로 무작위, 공개, 비교 연구를 시행하였다. 대상 환자를 무작위로 cefepime 단독요법군과 ceftazidime 및 tobramycin 병합요법군으로 나누어 투여하고 각각의 임상적 효능과 안전성을 비교하였다. 구강및 인후 점막염이 있는 환자에서 분리된 녹색 연쇄알 구균에 대한 항생제 내성 정도를 조사하였다. 결과 : 대상환자 89명 중 CA 투여군이 48예(53.9%), CT 투여군이 41예(46.1%)이었다. 발열의 유형별로 MDI는 18예(20.2%), CDI는 9예(10.1%), UF는 62예(69.7%)로 두 군 간에 차이가 없었다. CA 투여군과 CT 투여군의 임상적 호전률은 시험약 투여 후 2-4일째 각각 91.7%, 85.4% (P=0.31), 치료 종료 시 각각 91.7%, 100% (P=0.15)로 두 군간에 유의한 차이가 없었다. 치료 종료 시 CA 투여군과 CT 투여군의 세균학적 소실률은 모두 100%로 두 군간의 유의한 차이가 없었다(P=0.78). 점막염이 있는 환자로부터 녹색 연쇄알 구균이 분리된 경우는 25예(28.1%)이었으며, 분리된 녹색 연쇄알 구균은 penicillin, ceftriaxone, cefepime, vancomycin에 모두 감수성을 보였다. 약제 관련 이상 반응의 발생 빈도도 두 군간에 유의한 차이가 없었다. 결론 : 발열을 동반한 호중구감소증이 있는 악성 종양환자의 경험적 항생제로서 cefepime 단독요법은 ceftazidime 및 아미노배당체의 병합요법만큼 효과적이고 안전하였다. Background : Broad-spectrum antibiotic therapy has been recommended as an empirical regimen in cancer patients with febrile neutropenia. Cefepime is a fourth generation cephalosporin with good activity against both gram-positive cocci and gram-negative bacilli. Materials and Methods : To compare the efficacy and safety of cefepime alone with ceftazidime plus tobramycin as empirical regimen for adult cancer patients with febrile neutropenia, a randomized, open label, comparative trial was performed. If the patient showed clinical improvent 72 hours, antibiotic could be changed to oral ciprofloxacin. Clinical and microbiological responses were determined at 72 hours and at the end of therapy. To investigate the antimicrobial resistance of viridans streptococci, swab cultures were obtained from throat in all enrolled patients and antimicrobial susceptibility tests were performed by using microdilution method according to the NCCLS. Results : A total of 89 patients were enrolled. Forty-eight patients received cefepime alone (CA), and 41 patients received ceftazidime plus tobramycin (CT). Demographic and baseline clinical characteristics were similar in both groups (P>0.05). The initial clinical success rate at day 2-4 in group CA (91.7%) was similar with that in CT group (85.4%) (P=0.31). At the end of therapy, the final clinical success rate in CA group (91.7%) was similar to that in CT group (100%) (P=0.15). In 18 patients, with microbiologically defined infections, the eradication rate was 100% in both groups. Adverse events including liver dysfunction (21.3%) and renal dysfunction (2.2%), were similar in both groups (P=0.87). Viridans streptococci were isolated from the throat cultures in 25 cases, and all of these strains were susceptible to penicillin (MIC_(90) 0.12 ㎍/mL), cefepime (1 ㎍/mL), and vancomycin (0.12 ㎍/mL). Conclusion : Efficacy and safety of cefepime monotherapy was comparable to the combination of ceftazidime and tobramycin. It could be used as an alternative empirical regimen for treating cancer patients with febrile neutropenia.

졸-겔공정을 이용한 초고용량 캐패시터용 Nickel oxide 나노입자의 합성

김두현,송기창,변태강,송연호 조선대학교 생산기술연구소 2003 生産技術硏究 Vol.25 No.2

The Ni (OH)₂ nanoparticles with average diameter of 50 nm were synthesized by hydrolyzing nickel acetate with water, and were dispersed in the distilled water to prepare the coating solution. The electrodes for supercapacitor were prepared by dip-coating the coating solution on the Ni-foam. The electrodes heat-treated at several temperatures showed the highest specific capacitance, 160 F/g, at 250℃. It can be explained that the Ni(OH)₂ particles heat-treated at 100 and 200℃ on the electrodes contained the impurities such as acetate groups in the pores, and resulted in low specific surface areas. However, as the calcination temperature increases. the impurities incorporated in the pores are removed at 250℃, and thus, the particles on the electrodes show the highest specific surface area (177 ㎡/g).

Sol-Gel법과 수열처리에 의한 단일 분포 기공을 갖는 Titania 나노 분말 제조

김현태,신상일,송기창,강용 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.5

Sol-gel법에 의해 출발물질로 TTIP(titanium tetra-isopropoxide)를 사용하여 titania 분말을 제조하였으며, 이 분말을 autoclave에서 수열처리하여 그 물성을 고찰하였다. 수열처리에 의해 얻어진 분말은 많은 나노기공을 갖고 있었으며, 아나타제의 결정상이 나타났다. Sol-gel법에 의해 제조한 후 400℃이상에서 열처리하여 얻어진 titania 분말은 1차 입자들 사이의 기공(intra-particle pores)과 2차 입자들 사이의 기공(inter-aggregated pores)이 공존하는 bimodal의 기공분포를 보이는 반면, 200℃에서 수열처리한 분말은 1차 입자들 사이의 기공만 존재하는 monomodal의 기공분포를 나타내었으며, 크기도 매우 작아졌고(40-50 nm), 비표면적의 중가(50-100%)와 분말의 응집도 감소(30-40%)등 물성의 괄목할 만한 향상을 가져왔다. Titania powders were prepared from titanium tetra-isopropoxide (TTIP) by a sequence of sol-gel method and hydrothermal treatment The powders made by sol-gel method followed by hydmthermal treatment exhibited an anatase crystalline phase with numemus nano-size pores. The pore size distribution of the powders prepared by sol-gel method and calcination above 400 ℃ was bimodal with tine intra-particle pores (space between primary particles) and larger inter-aggregated pores (space between secondary particles). The powders by the hydrothermal treatment at 200℃ showed a monomodal pore size distribution with only intra-particle pores. The properties of titania powders could be improved by means of hydrothermal treatment considerably; the size could be reduced to 40-50 nm, specific surface area could be increased by 50-100% and the ratio of agglomeration could be reduced by 30-40%.