• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.790-795
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• 1997

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuransfurans are the archetype of toxic chemicals. So it has absorbed public attention. The majors primary sources of PCDDS and PCDFs are chemical, thermal and photochemical reactions. Municipal solid waste incinerator facilities has been reported as the major contributors of dioxins to the environment. In this paper, Dioxins and furans were examined emission gas and fly ash produced during combustion in municipal solid waste incinerator. More effective method for sampling, extraction was described. The sample was extracted using a soxhlet method and purified using silicagel, alumina and carbon fibre HPLC to remove interfering compound. The extract was then analyzed by HRGC/HRMS. The result of this study showed recovery standard was good and the data resembled those of thermal processes. Total dioxins and furans were $1076.20pg/Nm^3$ and $1452.34pg/Nm^3$ respectively. The amount of highly chlorinated compound was more than that of lowly chlorinated compound. The 2,3,7,8-substituted TCDD was Just 0.34% of the total dioxins/furans amount.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.67-78
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• 2007

The eye irritant test of lens washing agent, CLIWELL$^{TM}$ was conducted using Draize methods according to KFDA Guidelines. In addition, to test the potential toxicity of test articles, the ratio of inflammatory cells and non-inflammatory epitheloid cells was also observed using smear cytology methods against ocular discharge. At sacrifice, the histopathological changes on Cornea, Iris, Retina and Sclera were also observed in all animals. Slight irritancy of cornea and conjunctiva was observed at 1, 2 and 3 days after dropping in non-washing group. The MIOI of these points are detected as 4.50, 1.67 and 0.67, respectively. In washing group, slight irritancy of cornea and conjunctiva were observed at 1 and 2 days after dropping with MIOI as 0.67, respectively. Therefore, CLIWELL$^{TM}$ was considered as non-irritating materials because the MIOI is detected below 5.00 throughout the whole experimental periods in both washing and non-washing groups and the IAOI was also detected as 4.50. Except for significant increase of the inflammatory cell ratios in ocular discharge at 1 day after dropping of non-washing group compared to that non-treated intact eyes, no meaningful changes on smear cytology of ocular discharges are observed in this study. In addition, no abnormal histopathological changes on the cornea, iris, retina and sclera were also detected in CLIWELL$^{TM}$ dropping group compared to that of non-treated intact eyes.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.299-310
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• 2006

The eye irritant test of lens washing agent, $SOLOCARE^{TM}$ was conducted using Draize methods according to KFDA Guidelines 1999-61. In addition, to test the potential toxicity of test articles the ratio of inflammatory cells and non-inflammatory epitheloid cells were also observed using smear cytology methods against ocular discharge. At sacrifice, the histopathological changes on Cornea, Iris, Retina and Sclera were also observed in all animals. Slight (1~2 degrees) irritancy of cornea and conjunctiva were observed at 1, 2 and 3 days after dropping in non-washing group. The MIOI of these points are detected as 4.33, 3.33 and 2.00, respectively. In washing group, slight irritancy of cornea and conjunctiva were restricted to 1 and 2 days after dropping with MIOI as 3.00 and 1.33, respectively. Therefore, $SOLOCARE^{TM}$ was also considered as non-irritating materials because the MIOI is detected below 5.00 throughout the whole experimental periods in both washing and non-washing groups and the IAOI is also detected as 4.33 (1 day after dropping). No meaningful changes on smear cytology of ocular discharges are observed in this study compared to that of non-treated intact eyes. In addition, no abnormal histopathological changes on the cornea, iris, retina and sclera were also detected in $SOLOCARE^{TM}$ dropping group compared to that of non-treated intact eyes.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.51-52
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• 2000

생물공정의 운전에 있어서 적절한 공정변수가 부족한 경우가 많다. 이것은 멸균과정을 견딜 수 있는 신뢰성 높은 센서가 부족하기 때문이다[1]. 생물공정에 주로 사용되는 센서로서는 온도, pH, D.O., rpm, viscosoty 등이 있으나 이 센서들은 배양액의 물리적 혹은 화학적 상태를 측정할 수 있는 경우가 대부분이다[2]. 미생물의 대사활동과 관련이 있는 공정 변수로는 배출가스의 성분을 측정하여 얻을 수 있는 Oxygen uptake rate, Carbon dioxide evolution rate 및 Respiratory quotient가 있으며 현재 생물공정의 운전에 사용되고 있다[3]. 그러나 반복적인 센서의 보정과 연결관의 잦은 청소 및 보수를 필요로 하여 제한적으로 사용되고있는 실정이다. 자동화된 습식분석장치, Gas chromatograph, High Performace Liquid Chromatograph 혹은 Mass spectrophtometry 등을 온라인 샘플 처리장치와 연결하여 발효조의 배양액의 성분을 온라인으로 분석하고 공정의 운전에 응용하는 사례가 많이 발표되었다[4-6]. 고가의 장비 및 운전의 번거러움이나 추가적인 인력이 필요하므로 역시 특별한 경우에만 사용되고 있다. 이외에도 여러 종류의 온라인 센서 및 바이오 센서등이 개발되어 사용되고 있으나 역시 그 사용범위는 특수한 영역에 한정되어있다. 이와 같이 새로운 센서를 개발하여 공정변수를 측정하려는 시도중의 하나가 소프트웨어 센서의 개발이다. 이 것은 공정상에서 발생하는 1차 공정변수를 이용하여 배양액의 상태 혹은 2차적인 공정 변수를 추측해내는 것이다. 대부분의 경우 기존의 공정 변수를 사용하므로 추가적인 비용이 들지 않고 소프트웨어의 형태로 구현되므로 센서의 보정과 설치 및 유지관리의 노력이 매우 적은 장점이 있다. 본 연구에서는 생물공정에서 자동제어 과정에서 발생하는 여러 가지 공정상의 제어 신호로부터 새로운 공정 변수를 얻어내고자 시도하였다. 대부분의 생물공정에서는 pH의 자동제어가 필수적인데 자동제어 과정에서 발생하는 pH 제어 신호 및 pH의 변화 응답신호를 이용하여 배지의 완충용량의 변화와 알칼리의 소비속도를 온라인으로 측정할 수 있었다. 여기에 인공지능망을 설계하여 균체의 량을 온라인으로 추정하는 방법을 개발하였다 [7].산업용 발효조의 운전 온도는 주로 냉각수의 단속적인 공급에 의하여 항상 일정하게 조절된다. 따라서 냉각수의 냉각량을 측정하면 미생물의 배양시 발생하는 대사열량을 측정할 수 있게 된다. 본 연구에서는 실험실의 발효조를 냉각수의 단속적인 공급에 의하여 자동온도 조절이 되도록 개조하고 여기에 냉각수의 유출입 지점에 온도센서를 부착하여 냉각수의 온도를 측정하고 냉각수의 공급량과 대기의 온도 등을 측정하여 대사열의 발생을 추정할 수 있었다. 동시에 이를 이용하여 유가배양시 기질을 공급하는 공정변수로 사용하였다 [8]. 생물학적인 폐수처리장치인 활성 슬러지법에서 미생물의 활성을 측정하는 방법은 아직 그다지 개발되어있지 않다. 본 연구에서는 슬러지의 주 구성원이 미생물인 점에 착안하여 침전시 슬러지층과 상등액의 온도차를 측정하여 대사열량의 발생량을 측정하고 슬러지의 활성을 측정할 수 있는 방법을 개발하였다.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.91-100
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• 1992

Tissue origin of individual component proteins in crude extract of adult Paragonimus westermani was investigated. Major soluble component proteins were separated by disc-PAGE in 8% slab gel. By predefined Rf values, strips of gel containing each band protein was cut out. Each band protein was eluted by electrophoresis. Monospecific antibodies were prepared by immunizing rabbits with each band protein. When peroxidase-antiperoxidase (PAP) staining was done, antiserum to Band 1 reacted to content of eggs both in the worm and in the infected lung tissue. Antiserum to Band 2 reacted to parenchymal tissue of the worm. Antiserum to Band 4 showed the positive reaction at intestinal content while that to Band 5 reacted to the intestinal epithelial border. Antiserum to combined proteins of Bands 617 and that to Band 8 reacted to parenchymal tissue of the worm respectively. From the results, the origin of individual proteins in crude extract of adult P. westermani could be differentiated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.1-7
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• 2018

The gases emitted from internal combustion engines using fossil fuels are causing many social problems, such as environmental pollution, global warming, and adverse health effects on the human body. In recent years, the demand for renewable energy has increased, and government policy support and research and development are also active. In the collecting part of a solar energy system, which is widely used at home, propylene glycol (PG) (anti-freeze), as a heating medium, is mixed with water at a fixed value of 50%, and the heat is transferred to the collecting part at subzero temperatures. On the other hand, when leakage occurs in the heat medium in the heat collecting part, supplemental water is supplied to the solar heat collecting part due to the characteristics of the solar heat system, so that the concentration of antifreeze in the replenishing water becomes low. As a result, the temperature of the solar heat collecting part is lowered resulting in a frost wave, which causes economic damage. The purpose of this study was to develop a device capable of controlling the antifreeze concentration automatically in response to a temperature drop to prevent freezing of the heat collecting part generated in the solar energy system. The electrical conductivity of the H2O component was larger than that of PG, and the resistance increased with decreasing temperature. The PG concentration control values of 40, 50, and 60% should be controlled through calibration with a PG concentration of 39.6, 50.7, and 60.1%.

• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.1-8
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• 2021

Among the flare systems that handle discharged substances from safety valves, the knockout drum was a key facility for safety, but the installation standards were not clear, so it was necessary to review the standards acceptable to the workplace and regulatory agencies. After investigating the domestic and foreign technical standards of knockout drums and the deficiencies of previous studies, research was first conducted on the degree of mass discharge, the installation location of the intermediate knockout drum, and the effect of changes in the composition of the discharged material. As a result of the study under the process simulation conditions, the gas-liquid separation of the knockout drum was completed in a small amount of less than 7,500kg/hr. However, when more than that was released, the gas-liquid separation effect was small even with the addition of an intermediate knockout drum. In addition, when the composition ratio of the material easily condensed was increased (molar fraction 10%), the gas-liquid separation effect of the knockout drum increased in the case of mass release. The gas-liquid separation effect was analyzed to be greater when the knockout drum was installed adjacent to the stack than the knockout drum was installed adjacent to the process equipment.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.121-128
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• 2007

To develop the composting system to reduce the use of bulking agent, continuous composting was performed with farmer scale facility, The plant comprises a horizontal pit reactor closed inside a greenhouse and equipped with a turning machine moving on rails. The pit was 9m wide and 50m long and the maximum height of loaded materials was $1.8m^2$. The materials remained in the reactor for 5 months. During the composting process, temperature and water content measured and water balance was evaluated. The reaction temperature of composting was changed $30{\sim}50^{\circ}C$ and high in the middle and low in under composting piles. The moisture contents of the compost were approximately 70% during the experiment. The amount of effluent was 10.6% and $3.16m^3$ of pig slurry per $1m^3$ of bulking agent was treated during continuous composting process. BOD and SS reduction of the effluent in continuous composting was 86.5% and 92.2%, respectively. Indoor relative humidity in night time was changed between 80 and 100%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.48-58
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• 2006

The spray and combustion characteristics of liquid jet in cross flow with variation of injection angle are numerically studied. Numerical analysis was carried out using KIVA code, which may be used to generate numerical solutions to spray and chemical reactive fluid problem in three space dimensions and modified to be suitable for simulating liquid jet ejected into the cross flow. Wave model and Kelvin- Helmholtz(KH) /Rayleigh-Taylor(RT) hybrid model were used for the purpose of analyzing liquid column, ligament, and the breakup of droplet. Penetration length increases as flow velocity decreases and injection velocity increases. Numerical error increases as inflow velocity increases. The results of flame propagation contour in combustion chamber and local temperature distribution, combustion emissions were obtained.

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.239-244
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• 2007

For the simultaneous methane recovery and $CO_2$-stripping, we have been developed dual vent auto circulation bubble lift column reactor, and evaluate optimum conditions for monoethanolamine (MEA) solutions as a $CO_2$ absorbent. At the 5 wt% MEA solution, we investigated the pH change during $CO_2$-stripping and absorption reaction, $CO_2$-stripping rate with reaction time, methane recovery efficiency for various inflow rates of air, $CO_2$-stripping rate for flow liquid over flow height, and $CO_2$-stripping dependency on the temperature of absolvent solutions. The suggested optimum conditions for $CO_2$ recovery with MEA in the dual vent auto circulation bubble lift column reactor were 40 mm over flow liquid height, 1.5 L/min of air inflow rate, and $25^{\circ}C$ of absorbent solution temperature.