화학공장 운전용 다이내믹 시뮬레이터 설계에 관한 연구

劉一增 울산과학대학 1998 연구논문집 Vol.24 No.2

화학공장 운전용 다이내믹 시뮬레이터의 설계를 위한 기초조사 및 기본구조를 확립하고, 동특성 미분 방정식의 적절한 해를 구하기 위한 미분방정식 풀이 프로그램과 적분방정식 풀이 프로그램을 시뮬레이터 언어로 추천되는 C 언어로 작성하였다. 이를 이용하여 2 성분계 증류탑에서 외란을 주어 동특성 사례를 고찰하였다. This paper aims to establish a basic structure for the design of a dynamic simulation for operating chemical plants and to obtain effective solution of differential equation of a dynamic simulation. Differential equation solve program and integration equation solve program are conducted by C language. Researched is a dynamic simulation case of binary system distillator under the condition of disturbance.

화학공장 운전용 시뮬레이터 설계에 관한 연구

劉一增 울산과학대학 1995 연구논문집 Vol.21 No.-

이 논문은 모사 프로그램의 기본 구조에 대한 조사와 향후 제어 알고리즘의 발전 및 시험을 위해 사용되어질 컴퓨터 제어의 하드웨어 시스템에 대한 이론 제시를 위한 조사이다. C언어로 작성된 모사 프로그램은 입력자료에 의해서 이성분계에 있어서의 증류탑의 운전조건 및 각 단의 몰분율의 변화를 계산할 수 있다. This paper is aimed to investigate basic structure of simulator software and to set up a hardware system for the computer control, which will be used to develop and to test control algorithm in the future. Simulation program established by C-language can calculate the operating condition and mole fraction of column in binary system by using input data.

TiO_2 의 소결과 전기 전도도에 미치는 Nb_2O_5의 첨가 효과

劉一增,梁千會 울산과학대학 1985 연구논문집 Vol.10 No.2

TiO_2 루틸의 소결 및 전기 전도도에 미치는 Nb_2O_5 첨가효과에 대하여 첨가량 및 소결온도에 따른 소결도를 검토하였다. 낮은 저항값을 갖는 TiO_2 소자는 Nb_2O_5를 소량 첨가한 시료를 고온에서 소결하여 얻을 수 있었다. 아울러 Nb_2O_5의 첨가 효과에 대한 원자가 제어 이론에 대해서도 검토하였다. The effect on the addition of Nb_2O_5 to rutile have been investigated by electrial properties. The amount of additive and sintering temperatures greatly affect on the charactor of the bodies sintered. The specimens with small amount of Nb_2O_5 sintered of high temperatures showed the inhibition of sintering and increased electrical conductivity. These phenomena were explained in terms of the principle gf controlled valency.

Pd를 첨가한 SnO_2 소결체의 환원성 가스에 의한 전기전도도

劉一增,梁千會 울산과학대학 1985 연구논문집 Vol.10 No.1

SnCl_4로부터 조제된 SnO_2에 1wt%의 Pd를 염산염 또는 초산염의 상태로 첨가시키어 얇은 막형의 소자를 만들었을 때 수종의 환원성 기체 분위기하에서의 전기전도도에 어떤 영향을 미치는가를 온도 변화에 따라 검토하였다. 이 실험의 결과 1wt%의 Pd가 첨가된 SnO_2소자는 수소기체에 특히 민감함을 알 수 있었다. SnO_2-based powder with 1(wt%) PdCl_2 or Pd(NO_3)_2 have been prepared by using SnCl_4. SnO_2 gas sensors have been developed by a thick-film technology. The concentration of several gas vs. its detection valtage characteristics have been investigated on sintered SnO_2. From the results of these experiments, it is found that the thick-film sensor with 1(wt%) Pd(NO_3) has high sensitivity to hydrogen gas.

황토 내장재 제조공정 개발에 관한 연구

유일증,김병준,박진도 울산과학대학 2004 연구논문집 Vol.31 No.1

본 연구에서는 황토의 특징인 수분 조절능력, 흡착 능력, 항균능력 등의 성능을 갖는, 균열이 생기지 않고, VOCs 발생이 거의 없는 환경친화적 건축내장재를 개발하기 위하여 다음과 같은 연구를 수행하였다. 황토판넬 제조공정의 건조과정에서 균열현상의 방지 및 생(生)황토의 순기능을 위하여 무기성 Binder를 Sol-gel process에 의하여 Si-0-Si의 망목구조인 환경친화적 결착제를 제조하였다. 이를 이용하여 황토 내장재 제조공정-원료의 배합비율, Mold sizing, 건조공정-등의 운전조건을 확립하였다. 제조된 시제품의 특성치를 실험한 결과, 수분흡수 능력은 상대습도 80%, 온도 20'c에서 증습 건조과정을 거친 시료의 경우 165.3g-H₂0/m²로 자연건조과정을 거친 시료보다 높게 나타났다. 탈취 능력 실험에서는 암모니아 초기농도 179ppm에서 120분후 10ppm으로 99.4%로 제거효율이 우수한 것으로 확인하였다. 황토판넬의 내구성을 파악하기 위하여 압축강도 실험을 한 결과 증습건조 과정을 거친 시제품은 61.44㎏_(f)/cm²로 나타났다. 항균실험에서 배지에 colony가 발생되지 않음으로서 다소의 항균능력도 확인하였다. In this study, a new interior material using loess, which have good characteristics such as water controllability in the room, adsorption of VOCs, and antibacterial ability, was developed for making a fine view and habitat without crack. The environment-friendly cohesion material which have a network structure of Si-O-Si was made by the sol-gel process with inorganic binder to prevent cracks and to characterize of pure loess at drying process of the loess panel manufacturing. In the humidity controllability experiments as a specificity quality of test product the sample of increasing steam curing process had higher water absorption ability of 165.3g-H₂O/m²than that of air curing process at 80% relative humidity and 20℃. In ammonia absorption experiments, the elimination efficiency was up to 94.4%, from 179ppm to l0ppm, for 120minutes. In a compressive strength experiment to test durability of the loess panel, compressive strength of test product after steam curing process observed 61.44kgf/cm². It had also slight antibacterial capability.

LaFe₁­хMхO₃산화물의 CO산화 촉매 활성 및 감지 특성

林炳五,梁千會,劉一增 弘益大學校 1985 弘大論叢 Vol.17 No.2

Correlation of catalytic activity for the oxidation of CO and sensor response to CO was investigated. The perovskite-type oxides prepared by partial substitution of LaFeO₃with other 3d transition metal M to give LaFe₁_хMхO₃. The catalytic activity of LaFe₁_хCOхO₃(x=0 to 0.2) increase in X, but the highest sensor response was achieved at x=0.1. It was found that the sensor response increased in proportion to the catalytic activity, provided that the apparent activation energy for electrical conduction was unaffected by the substitution.

Continuous Production of Biodiesel from Vegetable Oils Using Novozym 435 Lipase

Hyun, Young-Jin,You, Il-Zeung 제주대학교 공과대학 첨단기술연구소 2005 尖端技術硏究所論文集 Vol.16 No.2

The immobilized Candida Antarctica(Novozym 435)-catalyzed transesterfication of vegetable oils was conducted on the batch and the CSTR system. The inactivation of immobilized lipase in batch operation relied on the amount of step-wisely added methanol, the co-solubility of t-butyl alcohol, and the emulsifier. It was not inactivated up to the 1:4 of oil to methanol due to t-butyl alcohol for one-step of addition. So, the limiting molar ratio was increased from 1:1.5 to 1:4. And the conversion of soybean oil containing more unsaturated fatty acid than rapeseed oil was a little high. The conversion of soybean oil on the CSTR was 96% at 0.7ml/min and 35℃under the 1:4 of molar ratio, two-step of addition, 1% emulsifier, 7% immobilized Candida lipase, the addition of t-butyl alcohol. The 10% used lipase in two times of reuse was not inactivated by the addition of 10% silica gel.

연구발표논문초록 : 화학공정 설계작업에 대한 PERT . CPM 의 응용연구

김우식,김병식,유일증 한국화학공학회 1978 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.16 No.5

MgO-Cr2O3-TiO2 산화물의 가스감지 특성

양천회,홍필선,유일증,임병오 한국산업안전학회 1986 한국안전학회지 Vol.1 No.1

Gas sensing materials for detecting inflammable gas such as alcohol, propane, acetic acid, carbon monoxide, hydrogen were developed by utilizing MgO-Cr₂O₃-TiO₂ system. Between 300℃ and 500℃, reversible chemisorption becomes dominant and the electrical canduction of P-type semiconductive with the gas chemisorption. The ceramic sensor exhibits a high sensitivity to particular reducing gas such as alcohol, whereas propane and butane have little effect on the resistivity. The time response of adsorption is estimated to be about 20 sec. On the other hand, the desorption process, which corresponds to oxidation due to oxygen adsorption, take more than 60 sec. Thus the ceramic sensor can be used as a alcohol sensor in an ambient atmosphere. As the oxygen concentration is increased from 0.1 to 10 precent(10³-10^6ppm), the resistance decreases rapidly but stabilizes at higher concentration.

수용액내 중금속 제거를 위한 미생물 흡착 공정(I)

서정호(Jung Ho Suh),서명교(Myung Gyo Suh),유일증(Il Zeung You),김석현(Seok Hyun Kim),박영식(Young Seek Park) 한국환경보건학회 1998 한국환경보건학회지 Vol.24 No.4

In recent years, waste heavy metals which have a reputation of detrimental effect on the en - vironment through the food chain are generated from mining, dyestuff, material, electric, and petroleum industries. In this study, the effect of heavy metals on human body and advantage or disadvantage of conventional technology for removal of heavy metals were reviewed, and biosorption process which have been deep studied recently was also investigated briefly. Conventional methods for removing heavy metals include chemical precipitation, electrolytic recovery, membrane technology, and ion exchange. These processes need to have pretreatment or aftertreatment, and may be ineffective or extremely expensive, especially when the concentration of heavy metals in solution are in the order of 1 to 100 mg/L. Biosorption process have lots of advantages in operating conditions and economical aspects and it is about to step into practical use in advanced states. The substances which have a capability to bind heavy metals are extracellular polymeric substances, cell wall, cell cytoplasm, and some excreta. The extracellular polymeric substances can be classified into proteins and polysaccharides excreted from microbial cells, and they may form complexation with heavy metals. The cell wall on the outside of the cytoplasmic membrane of the cell, determine the shape and the rigidity of the cell, have polysaccharides such as peptidoglycan and chitin, and bind with heavy metals well. It was reported that the organelles inside the cell membrane can sorb heavy metals too.