http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
초저온 액화가스 기화기의 열 교환성능 비교에 관한 연구
김필환(Pil-Hwan Kim),김철표(Chul-Pyo Kim),정효민(hyo-Min Jeong),정한식(Han-Shik Chung),이용훈(Yong-Hun Lee) 대한설비공학회 2008 설비공학 논문집 Vol.20 No.10
Air-heating vaporizer usually is used to regasify LNG at satellite areas because of the small demand of natural gas there. The co㎜on type of air heating vaporizer which exists in the market is the longitudinally finned type with 8 fins, 55 ㎜ fin length and 2 ㎜ fin thickness. To contribute in developing an efficient air-heating vaporizer, experiment on finned type air-heating vaporizer using 8 fins, 50 ㎜(fin length) with 2 ㎜(fin thickness) which exist in the market and 4 fins, 75 ㎜(fin length) with 2 ㎜(fin thickness), which is proposed, were conducted. Then, both types of vaporizers are compared. The experiments were conducted in one hour by varying the ambient condition and the length of the vaporizer. The ambient air was controlled so that it has the same temperature, humidity and air velocity with air condition in every season available and the length was varied 4000 ㎜, 6000 ㎜ and 8000 ㎜ for each type of vaporizer. Additional experiment with longer duration, i.e. In this experiment, the main aspects in analyzing the characteristics of the air heating vaporizer the inlet-outlet enthalpy difference and the outlet temperature of the working fluid. LN₂ is used to substitute LNG because of safety reason. The results show that the characteristics of the finned type 4fin75le vaporizer are comparable to finned type 8fin50le vaporizer.
윤희정 ( Hee Jung Yoon ),정준표 ( Jun Pyo Chung ),최승호 ( Seung Ho Choi ),김철식 ( Chul Sik Kim ),강병승 ( Byung Seung Kang ),이태희 ( Tae Hee Lee ),지상원 ( Sang Won Chi ),조준식 ( Jun Sik Cho ),문범수 ( Byoung Soo Moon ),이관식 대한소화기학회 2003 대한소화기학회지 Vol.41 No.2
Background/Aims: The purpose of this study was to evaluate the prognosis of gastric proper muscle (pm) cancer and its prognostic factors to identify a high risk group of patients with recurrence. Methods: Consecutive 154 patients (mean age, 57.6 years; M;
새로운 주름개선 소재: 3,9-diferuloyl-6-oxopterocarpen (Tensolin-F<sup>®</sup>)의 개발과 화장품 응용
이범천 ( Bum-chun Lee ),이정재 ( Jeong-jae Lee ),박성민 ( Sung-min Park ),김철배 ( Chul-bae Kim ),심관섭 ( Gwan-sub Sim ),김진화 ( Jin-hwa Kim ),이근수 ( Geun-soo Lee ),이천일 ( Chun-il Lee ),표형배 ( Hyeong-bae Pyo ) 대한화장품학회 2004 대한화장품학회지 Vol.30 No.1
3,9-Dihydro-6-oxopterocarpen과 ferulic acid의 에스테르 반응을 통해 페룰산 유도체인 3,9-diferuloyl-6-oxopterocarpen (Tensolin-F<sup>®</sup>)를 합성하여 이를 함유한 주름개선 화장품을 개발하였다. Tensolin-F<sup>®</sup>는 농도 의존적으로 DPPH와 superoxide radical에 대한 소거효과를 나타냈으며, 각각 0.8 mM에서 78%, 0.053 mM에서 92.9%로 DPPH와 superoxide radical을 소거하여 우수한 항산화 효과를 나타내었다. MMP-1 효소 활성 저해 효과도 0.16 mM에서 74%를 저해하였다. HDF에서 UVA에 의해 발현이 증가되는 MMP-1의 발현 저해 효과는 Tensolin-F<sup>®</sup> 0.8 uM에서 85.5%로 단백질 수준에서 모두 농도 의존적으로 발현 저해효과가 나타났다. Tensolin-F<sup>®</sup>를 함유한 제품의 피부 주름개선 효과 평가 결과, Tensolin-F<sup>®</sup>를 함유한 화장품을 약 8주 간 도포한 경우 유의한 주름개선 효과가 있음을 확인 할 수 있었다. 본 연구를 통하여 Tensolin-F<sup>®</sup>는 항산화 효과와 MMP-1활성 저해 효과 및 UVA에 의한 MMP-1의 발현을 저해하는 효과가 나타났으며 새로운 주름개선 기능성 화장품으로 이용될 수 있을 것이다. As a novel anti-wrinkle agent, 3,9-diferuloyl-6-oxopterocarpen (Tensolin-F<sup>®</sup>) has been synthesized and its anti-aging effects have been investigated. In the present study, to investigate the relationship between aging and Tensolin-F<sup>®</sup>, we examined its effect on scavenging activities of radicals and reactive oxygen species (ROS), in vitro inhibition activity of matrix-metalloproteinase (MMP) and expression of UVA-induced MMPs in human dermal fibroblasts (HDF). Tensolin-F<sup>®</sup> was found to show activities of scavenging radicals and ROS with the IC<sub>50</sub> values of 0.2 mM and 0.95 mM against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide radicals, respectively, in the xanthine/xanthine oxidase system. Fluorometric assays for the proteolytic activities of MMP-l (collagenase) were performed using fluorescent collagen substrates. Tensolin-F<sup>®</sup> inhibited the activities of MMP-l in a dose-dependent manner and the IC<sub>50</sub> values calculated from semi-log plots were 0.025 mM. Also, UVA induced MMP-1 expression was reduced 85% by treatment with Tensolin-F<sup>®</sup> at 0.8 uM, which was reduced dose-dependent manner. The results of clinical study showed that 4.8 mM Tensolin-F<sup>®</sup> treated group reduced wrinkle significantly compared with placebo treated group (P<0.05). Taken together, these result suggest that Tensolin-F<sup>®</sup> act as an anti-wrinkle agent by taking effects to antioxidation and reducing UVA-induced MMP-l production.-l production.
이승화(Seung Wha Lee),이재광(Jae-Gwang Lee),채광표(Kwang Pyo Chae),권우현(Woo Hyun Kwon),김철성(Chul Sung Kim) 한국자기학회 2009 韓國磁氣學會誌 Vol.19 No.2
MnFe₂O₄ nanoparticles have been prepared by a sol-gel method. The structural and magnetic properties have been investigated by XRD, SEM, and Mossbauer spectroscopy, VSM. MnFe₂O₄ powder that was annealed at 250 ℃ has spinel structure and behaved superparamagnetically at room temperature. MnFe₂O₄ annealed at 400 and 500 ℃ has a typical spinel structure and is ferrimagnetic in nature. The estimated size of superparammagnetic MnFe₂O₄ nanoparticle is around 17 ㎚. The hyperfine fields of the A and B patterns at 4.2 K were found to be 508 and 475 kOe, respectively. The blocking temperature (T<SUB>B</SUB>) of superparammagnetic MnFe₂O₄ nanoparticle is about 120 K. The magnetic anisotropy constant and relaxation time constant of MnFe₂O₄ nanoparticle were calculated to be 4.9 × 10? ergs/㎤.
김철,주동표,김정근 한국화학공학회 1997 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.35 No.2
초임계 유체상과 액상이 순환되는 상평형 실험장치를 사용하여 50℃, 101-178bar 사이의 초임계 CO₂-C₂H_5OH-H₂O계의 평형조성을 측정하고 이 결과를 Peng-Robinson의 상태방정식을 이용하여 해석하였다. PR-EOS를 본 3성분계에 적용함에 있어 adjustable parameter ε(ε_Ⅰ, ε_Ⅱ, ε_Ⅲ)을 사용하는 새로운 혼합규칙을 제안하고 이때의 계산결과를 binary interaction parameter k를 사용하는 전통적 방법과 비교하였다. Parameter ε을 사용하여 추정된 평형 조성을 실측치와 4% 이내의 오차로 부합되었으며 특히 초임계 유체상의 조성은 실측치와 1.5% 이내로 잘 일치하였다. 실험적 사실에 기초하여 온도 범위 40-60℃ 압력 범위 101-185bar 사이에 적용될 수 있는 ε과 온도 사이의 정량적인 관계식을 제시하였다. Using a circulation-type apparatus, equilibrium compositions of a supercritical CO₂-C₂H_5OH-H₂O system under the conditions of ~50℃ and 101-178bar were measured experimentally and were compared with the values predicted by the Peng-Robinson equation-of-state. In applying PR-EOS, a new mixing rule including a new adjustable parameter ε(ε_Ⅰ, ε_Ⅱ, ε_Ⅲ) was proposed and the equilibrium compositions predicted using the ε were compared with the results based on the conventional mixing rule. Equilibrium compositions computed by using the parameter ε agreed with the experimental data within 4% AAD. It was found that the prediction by the newly developed procedure was quite satisfactory for the supercritical fluid phase. resulting in 1.5% AAD. From the experimental observations, an empirical correlation of ε with temperature was proposed which may be applicable for the operating conditions between 40-60 ℃ and 101-185bar.
유동층 반응기를 이용한 Isophthalonitrile 로부터 Tetrachloroisophthalonitrile 의 합성에 관한 연구
김철,임병규,주동표 한국화학공학회 1991 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.29 No.2
Isophthalonitrile(IPN)을 염소화하여 Tetrachloroisophthalonitrile(TPN)을 합성하는 반응의 거시적인 반응 기구 및 반응속도를 연구하고 아울러 유동층 반응기를 이용하여 TPN을 합성하기 위한 반응기의 설계 및 조작조건들을 구하였다. 고정층 반응기를 이용하여 얻은 실험치와 이른치를 비교함으로서 TPN의 합성반응은 각 단계가 의1차반응인 연속반응임을 알았으며 반응기의 온도가 300℃ 때의 속도상수를 구하였다. 유동층 반응기의 설계 및 조업에 필요한 기본 데이터들을 얻기 위하여 입경과 조업 온도에 따른 촉매의 최소 유동화속도를 조사하였으며 이를 기본으로 하여 설계 제작한 벤치 스케일 유동층 반응기에서 -7O+100mesh의 30wt% FeCl₃/활성탄 촉매를 사용하여 순도 95% 이상의 TPN을 합성하기 위한 Cl₂/IPN의 몰비, 반응온도, 체재시간 및 유동층의 H/D의 값 등을 결정하였다. Macroscopic reaction kinetics of the chlorination reaction of isophthalonitrile(IPN) to produce tetrachloroisophthalonitrile(TPN) was studied and the optimal design and operating conditions of a fluidized bed reactor for the chlorination of IPN were investigated experimentally. Comparing the experimental data obtained from a fixed bed reactor with the theoretical ones, the IPN → X →TPN type consecutive reaction mechanisms and pseudo-first order reaction rate for each step were found satisfactory and the kinetic rate constants for each step at 300℃ were obtained. Experiments were conducted in a lab-scale fluidized bed column in order to obtain the information on the minimum fluidizing velocity of catalyst which in turn served as the basis for the design and operation of a bench-scale fluidized bed reactor. The chlorination reactions were undertaken in this reactor using the 30 wt% FeC1₃/activated carbon particles of -70+ 100 mesh sizes as the catalyst to determine the optimal operating conditions for the production of TPN of purity greater than 95%, which include temperature, molar ratio of Cl₂/IPN in the feed and mean residence time. Optimal H/D ratio was proposed also for the design.