LaCoO3 산화물의 에탄올 감지특성에 미치는 CaO 의 영향

양천회,임병오,손태원 한국산업안전학회 1988 한국안전학회지 Vol.3 No.2

The perovskite-type compounds La(1-x)Ca_xCoO₃ were synthesized, their thermochemical properties and the gaseous sensitivity were investigated in ethanol vapor. The maximum response for detecting gas corresponded with the exothermic peak of DTA experiment. In any case the substituent was increased, the responsive ratio for detecting gas was grown upon, However, the needed time for response was later, and the operating temperature was elevated. The mechanism of this electrical conductivity was explained by the oxygen ionic diffusion through oxygen vacancy produced by the substituent.

졸 겔법에 의한 TiO2 - SiO2 합성 및 광촉매활성

양천회,류완호 한국산업안전학회 1999 한국안전학회지 Vol.14 No.1

TiO₂ and xTiO₂-ySiO₂ system photocatalysts were developed by sol-gel method based on the change of production parameters, and their structure of crystallization and the specific surface area was measured. Considering the efficiency of the ethanol decomposition using the catalyst, the conclusion was made as follows: 1) By means of X-ray analysis of TiO₂ powder that is obtained from water and Titanium alkoxide with various molar ratios, it is shown that structure of crystallization is a dominating structure and, on the other hand, the crystallization of rutile also partly exists. The specific surface area is at its maximum value at R=6, which is the molar ratio of water vs. alkoxide, whereas its value goes down as the molar ratio increases. In the reaction of using TiO₂ catalyst, the ethanol is decomposed into the extent of 15∼30%r in an hour and three hours are necessitated for 70% decomposition. 2) TiO₂/SiO₂ powder is developed from Titanium and Silicon alkoxide by a hetero-condensation process. The increase of SiO₂ contents causes the decrease of the degree of crystallization of the gel, whereas the specific surface area preferentially increases. In the decomposition inaction of the ethanol, the decomposition efficiency represents 25∼60% in an hour. It is, however, examined that the efficiency inactively increases corresponding to the duration of reaction time. It is shown that more than 90% of ethanol is decomposed when reaction time is about three hours and the efficiency illustrates the maximum value for 60-TiO₂/40-SiO₂ catalyst.

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.

r-Fe₂O₃소결체의 가스감지 특성

梁千會 大田工業大學 1989 한밭대학교 논문집 Vol.6 No.2

ABSTRACT Gas Sensing materials for detecting of inflammable gases such as iso-butane were developed by Fea 04 as the principal sensing material. The redox reaction between y-FezOa and Fe3-.r04 at the surfaces ofy-FeaOa particles is responsible for the change of resitivity of their -Fea Oa sensor and the gas sensitivity depended on the crystal structure. Gas Sensing materials for detecting of inflammable gases such as iso-butane were developed by Fe_3O_4 as the principal sensing material. The redox reaction between γ-Fe_2O_3 and Fe_(3-χ)O_4 at the surfaces of γ-Fe_2O_3 particles is responsible for the change of resitivity ofγ-Fe_2O_3 sensor and the gas sensitivity depended on the crystal structure.

저밀도 폴리에틸렌 왁스의 산화공정에 관한 연구

양천회,이동진 한밭대학교 2003 한밭대학교 논문집 Vol.20 No.-

In this basic study we observed the basic reaction parameters such as time, temperature, oxygen concentration and catalysts in the oxidation reaction of low molecular weight polyethylene(PE) wax by analyzing the acid value, physical and chemical properties of oxidized PE wax to develop a new oxidation process. The purpose of this study was developing a manufacturing and acid-value-controlling technology of oxidized polyethylene waxes by observing the effect of the reaction parameters on the acid value in the oxidation reaction of low molecular weight polyethylene. Acid values were increased with temperature increase in the rage of 150℃ ~ 180℃, but decreased beyond 190℃. Acid values were also increased with oxygen concentration. As the oxidation reaction proceeds, the molecular weight and softening points of oxidation products were decreased by cracking reaction, but the viscosities were increased. We could observe that the size of crystallites were decreasing with the oxidation reaction progress. To obtain a high acid-value product in a mild condition, we adopted free radical catalysts and the acid value of the product using the catalysts was higher than the product obtained without the catalyst in the same reaction condition. The effective catalysts were DCPO(dicumyl peroxide), HOPO(t-butyl peroxy 2-ethyl hexanoate) and BPO(benzoyl peroxide) having long half-life.

Al₂O₃와 Li₂O를 첨가한 ZnO소결체의 가스감지 특성

林炳五,洪弼善,梁千會 弘益大學校 1986 弘大論叢 Vol.18 No.2

The effects of simultaneous addition of Al₂O₃ and Li₂O upon the sensor properties of porous zinc oxide sintered bodies have been investigated by resistivity measurements with various surrounding gas atmosphere. The appropriate high resistivity obtained by simultaneous addition of Al₂O₃ and Li₂O showed high sensitivity for inflammable gases at high temperature 300~500℃. The specimen with small amounts of Li₂O sintered at high temperature show promotion of sintering and the increased electrical resistivity.

농공단지 조성에 따른 하천 수질관리 대책에 관한 연구 : 충청남도 지역을 중심으로 Centering around Area of Chung Chong Nam Do

양천회 한국산업안전학회 1994 한국안전학회지 Vol.9 No.1

A study of stream pollution caused by construction of the Industrial Complex in Agricultural Area of Chung Chong Nam Do were descrived here. The five main results of this studies are summerized. First, since 1988, among the companies moved in the industrial complex area, the number of electric and electronic companies have increased compared with food companies requiring much BOD. This is very desirable to reduce the water pollution. Second, the average Biochemical Oxygen Demand(BOD) of Masan stream was the highest and it was decreased in the order of Yudug, Jo and Jungan stream. Third, although the concentration of heavy metals such as Cd and Cr^(6+) are not off the limit and the amount of it is small, it is desirable to introduce a chemical process to remove these metals. Fourth, since the wastewater from industrial complex area is the major factor in stream pollution, the laws associated with environmental protection should be enforced even then if the industrial complex area with food and chemical companies produce wastewater less than 500ton/day. Fifth, it is required to improve a facilities which separete living wastewater from inderstrial wastewater in Kaya-gok and Nojang industrial complex areas.

Titania 광촉매에 의한 페놀의 광분해

양천회,홍필선 大田産業大學校 1999 한밭대학교 논문집 Vol.16 No.1

TiO_2 and x TiO_2-y SiO_2 system photocatalysts were developed by sol-gel method based on the change of production parameters, and their structure of crystallization and the specific surface area was measured. Considering the efficiency of the phenol degradation using the catalyst, the conclusion were obtained as follows: By means of X-ray analysis of TiO_2 powder that is obtained from H_2O/Titanium alkoxide with various molar ratios, it is shown that crystal structure of anatase type is a dominating structure and, on the other hand, the structure of rutile also partly exists. The specific surface area is at its maximum value at R=6, which is the molar ratio of water vs. alkoxide, whereas its value goes down as the molar ratio increases. TiO_2-SiO_2 mixed compound photocatalysts were developed from Titanium and Silicon alkoxide by a hetero-condensation process. The increase of SiO_2 contents causes the decrease of the degree of crystallization of the gel, whereas the specific surface area preferentially increases. The maximum degradation rate of phenol is shown in 60 TiO_2-40SiO_2 catalyst.

La-(1-x)Sr_xCoO_3 산화물의 에탄올 감지특성

양천회 大田工業大學 1988 한밭대학교 논문집 Vol.5 No.2

The perovskite - type compounds La_(1-x)Sr_xCoO_3 were synthesized, their thermo-chemical properties and the gaseous sensitivity were investigated in ethanol vapor. The maximum response for detecting gas corresponded with the exothermic peak of DTA experiment. In any case the substituent was increased, the responsive ratio for detecting gas war grown upon. However, the needed time for response was later, and the operating temperature was elevated. The mechanism of this electrical conductivity was explained by the oxygen ionic diffusion through oxygen vacancy produced by the substituent.

폐광 광재와 유출수가 주변 토양과 하천오염에 미치는 영향

양천회,고장석 大田産業大學校 1998 한밭대학교 논문집 Vol.15 No.1

This study was investigated the extent of heavy metal contamination in areas of the soil and river by the effluent and abandoned mines in Chung Chong Nam Do. The abandoned mines were Gubong gold mine and Sinsung coal mine. The results were as follows. The concentrations of As and Pb in Gubong mine were 309.2mg/kg and 1163.5mg/kg which is above the soil quality standard. Cd concentration also was 14.70mg/kg which is exceeded warning level. The heavy metal contaminations in the vicinal paddy and dry field soil area were higher than those in coal mine area. However, As concentration was 29.29mg/kg which is exceeded the warning level as of 10.22mg/kg. The river water quality detected shows high Pb, As and Cd in Gubong stream and Cd, Cu and Pb in Sungju stream.