연구발표논문초록 ;명반석의 Ammonia 추출잔사로 부터 Alumina제조

조철형,김숭형 한국화학공학회 1974 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.12 No.6

명반석으로 부터 Zeolite 합성 반응 속도에 관한 연구

조철형,신성의,김숭평 조선대학교 생산기술연구소 1981 生産技術硏究 Vol.1981 No.-

Sodium aluminosilicate, sodium A zeolite and hydroxysodalite were obtained by treating OK-mai Mt.―alunite with IN aqueous sodium hydroxide solution for one to twenty hours and with temperature range from 60 to lOO℃. the reaction mechanism was observed as first order series reation as follows: ◁수식삽입▷ (원문을 참조하세요) By applying the above reaction mechanism, rate constants and activation energies measured. The activation energies of the reactions from alunite to sodium aluminosilicate, from sodium aluminosilicate to sodium A zeolite, and from sodium A zeolite to hydroxysodalite were 9 kcal/mol, 20 kcal/mol, and 18 kcal/mol, respectively.

Vibrio vulnificus의 세균학적 성상에 관한 고찰

趙哲衡,曺基學 조선대학교 환경연구소 1988 環境公害硏究 Vol.5 No.-

V. Vulnificus has been recognized as a serious pathogen causing life threatening septicemia. Its infection developed after eating raw oyster or raw fish, especially in patients with preexisting liver disease, alcohlism and diabetes mellitus. From January 1988 to December 1987, auther isolate the 28 cases of the V. vulnificus from necrotic skin lesion, bulla fluid and blood of septic patients admitted to the CNUH. The results obtained are as follows. 1. Without certain inhibitory factors, V. vulnificus grew well on common blood agar and classified as Oliver's group Ⅲ by biochemical characteristics. 2. V. vulnificus grew vere poorly without the added NaCl, but grew well on media with 0.25∼6.0% NaCl, especially 1∼3% NaCl, which is same as that of seawater. 3. Range of pH for growht is relatively wide, pH 5.0∼9.0. This organism grew at 20∼42℃ but the optimal temperature for growth was 37℃. Because V. vulnificus did not proliferate but survive at 5℃ or -20℃, it was suggested that this organism could pass the winter. 4. In susceptibiliry test, this organism were susceptibility to most of tested antibiotics except to colistin. These results indicate that person with preexisting severe hepatic dysfunction, heavy alcohlism and certain immunosuppressive states should avoid having raw sea fish and oyster etc. and an early treatment is suitable for V. vulnificus infection.

Gelatin-Na-Cellulose Sulfate 사이의 Complex 생성에 관한 연구

조철형,박혜령 조선대학교 생산기술연구소 1986 生産技術硏究 Vol.8 No.1

This study deals with the formation of gelatin-Na-cellulose sulfate complex. Investigations were conducted on the influences of pH, mixing ratio, contacting patterns of reactants and reaction temperature for the complex formation as well as on binding features and solubility of the complex formed. The results were as follows : 1. The complex was formed by the electrostatic forces as gelatin was strongly protonated below the iscelectic point, but above that point formed by hydrogen bond. 2. When the ratio of polycation to polyanion was below 1/3, the complex was soluble, and when the ratio above 1/1 it became insoluble. 3. In case of the back titration of complex which was formed jat acidic pH with NaOH, hydrogen bond increased markedly as compared with that of alkaline pH. 4. In the contacting pattern adding SCS solution to gelatin solution, the turbidity was larger than that of the inverse pattern. 5. The complex formation was promoted following to the degree of NaCI added, and the effects of NaCI on turbidity was remarkably evident around the isoelectric point.

Polymeric Drug의 합성과 그 특성에 관한 연구(Ⅱ) : Experiments with poly(N-acryloxysuccinimide) and acetaminophen

조철형,나재운 조선대학교 생산기술연구소 1990 生産技術硏究 Vol.12 No.2

Two major reasons for the inefficiency of conventional chemotherapy are the rapid dilution of the drug as it diffuses from the required target site, and the ease of excretion of small-molecule drugs through the kidneys. Thus, much larger quantities of the drug must be introduced into the body than should be needed to correct the medical problem. Water-soluble polymers diffuse slowly through the tissues and, moreover, would not be excreted as rapidly as small molecules because macromolecules cannot normally pass through semipermeable membranes. Thus, a polymer-bound drug should offer considerable advantages over a small molecule drug. The structures of polymer drugs were characterized by IR & ¹H-NMR spectroscopic methods. The pyrogen test of polymer drugs proved to be negative. The intrinsic vlscosity〔η〕 of the polymer drugs was 0.76㎤/g & 0.78㎤/g, respectivelly. The activation energy(Ea) of the polymer drugs was decreased with increasing the concentration of acetaminophen. Polymer drugs with high activation energies were temperature-sensitive ; Polymer drugs with low activation energies were relatively tempera ture-insensitive.

동하중상에서 인공무릎관절의 생체역학적인 비교 연구 ( A Biomechanical Study on the Tibial Components Under Dynamic Loding )

조철형,조용균,최재봉,최귀원,이태수 대한기계학회 1998 대한기계학회 춘추학술대회 Vol.- No.-

다성분계 증류에 있어서 단수와 환류비와의 관계에 대하여(I)

조철형,조성휴,신성의,전윤,송연호,권규혁,김선일,김정규,최형일,신대윤,고기성 조선대학교 생산기술연구소 1981 生産技術硏究 Vol.1981 No.-

This study presents a new method for mathematical simulation of equilibrium stage operations. The procedure solves component material equations with Thomas algorithm and induces to θ-method in order to decrease error. Summation equations are handled with Newton-Raphson method. Therefore, the method can be used for all types of equilibrium stage processes. Additionally, the use of the method presented in this study insures solutions which are stable and more rapid without complexibility. In order to validate the proposed method, the results comparing rigorous method with short-cut method are as follows; 1) convergence is stable and more rapid than others. 2) about 10% error in distillate and bottoms composition of each component. 3) about 13% error in total theoretical number of plates. 4) about 17% error in the feed plate. 5) the procedures are presented for calculations to design distillation column.

Decellularlized Matrix in Organ Transplantation

조철형 한양대학교 의과대학 2014 Hanyang Medical Reviews Vol.34 No.4

Liver transplantation is the only known treatment for patients with end-stage liver failure, but this therapy is limited by the shortage of donor organs. Hepatic tissue engineering combining biomaterial scaffolds and cells have been used as a promising strategy to create engineered liver graft for liver regeneration. Despite significant progress in this field, attempts to create clinically transplantable whole organs have not been as nearly successful. Recently, whole organ decellularization techniques have emerged as a new therapeutic strategy for organ replacement and provided feasibility for clinical translation. The perfusion decellularization method was applied to the whole organ for efficient removal of cellular components and generated organ scaffolds that can maintain the extracellular matrix (ECM) and vascular structure of the native organ. This review paper describes current progress in organ bioengineering for the development of transplantable liver grafts.

전 슬관절 치환 성형술에 사용되는 초고분자량 폴리에틸렌 삽입물의 접촉응력에 관한 유한요소해석

조철형,최재봉,최귀원,윤강섭,강승백,Jo, Cheol-Hyeong,Choe, Jae-Bong,Choe, Gwi-Won,Yun, Gang-Seop,Gang, Seung-Baek 대한의용생체공학회 1999 의공학회지 Vol.20 No.1

인공 슬관절에 사용되는 초고분자량 폴리에틸렌(Ultra-high molecular weight polyethylene : UHMWPE)의 마모는 삽입물의 수명을 결정하는 주요 요인으로 작용한다. UHMWPE의 마모로 입자가 발생하여 조직반응을 일으키고 이에 따른 일련의 반응으로 골용해가 일어나 인공관절의 실패의 원인으로 작용한다. 여러 보고들에 의하면 관절 운동시 발생하는 접촉응력은 UHMWPE의 마모에 영향을 미치는 주요한 인자 중 하나로 알려져 있다. 그러나 이러한 보고들은 관절 접촉면에서의 접촉 조건만을 고려했고 UHMWPE 삽입물을 지지하고 있는 금속 지지판과의 접촉면에서의 접촉 조건은 고려하지 않았다. 본 연구에서는 이러한 접촉 조건들을 고려하여 UHMWPE의 모양, 두께, 마찰, 굴곡 정도 그리고 구성 요소들에 대한 UHMWPE 표면과 내부에서의 응력해석을 통해 이들 변수가 UHMWPE의 마모현상에 미치는 영향을 알아보았다. UHMWPE의 모양에 따른 관절의 일치정도(conformity)에 대한 영향의 경우, 일치정도가 높은 모델이 응력을 줄여줄 수 있는 유형으로 나타났으며, 금속 지지판과의 접촉면에서 접촉조건을 준 경우가 완전히 결합된 것으로 가정한 경우보다 UHMWPE 내부에서의 최대 응력이 1-2mm 더 아래에서 나타났다. 또한 UHMWPE로만 된 유형이 금속 지지판이 있는 유형보다 낮은 응력분포를 보여줌으로써 높은 응력으로 인한 UHMWPE의 마모와 균열을 줄이기 위해서는 UHMWPE로만 된 유형의 삽입물의 사용이 좋을 것으로 사료되었다. Because of bone resorption, wear of ultra-high molecular weight polyethylene(UHMWPE) in total knee arthroplasty has been recognized as a major factor in long-term failure of knee implant. The surface damage and the following harmful wear debris of UHMWPE is largely related to contact stress. Most of the previous studies focused on the contact condition only at the articulating surface of UHMWPE. Recently, contact stress at the metal-backing interface has been implicated as one of major factors in UHMWPE wear. Therefore, the purpose of the is study is to investigate the effect of the contact stress for different thickness, conformity friction coefficient, and flexion degree of the UHMWPE component in total knee system, considering the contact conditions at both interfaces. In this study, a two-dimensional non-linear plane strain finite element model was developed. The results showed that the maximum value of von-Mises stress occurred below the articulating surface and the contact stress was lower for the more conforming models. All-polyethylene component showed lower stress distribution than the metal-backed component. With increased friction coefficient on the tibiofemoral contact surface, the maximum shear stress increased about twofold.

氣·液流動層 의 工業的 利用 : 酸化알루미늄製造에 관하여

조철형,조병욱,김숭평 조선대학교 생산기술연구소 1979 生産技術硏究 Vol.1979 No.-

Depostion rate on oxidaition reaction of sodium aluminate solution, holding in airblowing system(gas-liquid fluidized bed), was obtained. The results were also discussd on effects of concentration, temperature on the reaction and of air blowing velocity.