• Environmental Analysis Health and Toxicology
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• v.5 no.1_2
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• pp.45-50
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• 1990

In order to investigate the phototoxicity of five phenothiazine derivatives and one thioxanthen derivative were examined by using in vitro method based on growth inhibition of Candida albicans and red blood cell hemolysis. Effects of the test compounds on RBCs were monitored with a spectrophotometer and a drug PI in the Candida albicans was calculated on the basis of the lowest concentration giving a yeast-free zone. All phenothiazines phototoxic in the red blood cell hemolysis method were positive in the yeast test except promethazine. It was also observed that toxic photo-products were formed by perphenazine and chlorpromazine in the red blood cell hemolysis.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.119-119
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• 2003

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.129-136
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• 2004

Environmental factors for automotive consist of temperature, humidity, vibration(sine & random), gas, an electrical load and so on. These environmental factors are impressed in a automotive. Dependability is essential requirement in many electronic parts. Among components of automotive, the connector connecting electrical signals is one of the most important parts. Automotive -connector is inspected according to each manufacturer's test standard in which dependability should be considered. This paper aims to verify that current test standard is suitable for dependability, and present an inductive life test for automotive connector based on the field data in use-condition.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.969-974
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• 2002

Recently, many studies are performed according to increased interests about factory or room acoustics. In this study, the inside and environmental noise conditions of Diesel-locomotive load test building were investigated by multi-channel noise measurement system. In addition to this, the mitigation effects of environmental noise from this test building were analyzed using commercial software.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.639-645
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• 2012

The purpose of this study is to identify the possibility of the CMP wastewater treatment from semiconductor fabrication under operating tubular membrane with coagulants. To find suitable coagulants treating CMP wastewater, we conducted Jar-test. After Jar-test experiments suitable coagulants are PAC(17%), $Ca(OH)_2$ and optimum coagulant dosage is PAC(17%) 10mg/L, $Ca(OH)_2$ 110 ~ 120mg/L. Based on these results, the tubular membrane was applied to CMP wastewater, the turbidity removal efficiency is $Ca(OH)_2$ > PAC(17%) > Nothing. The fast cross-flow velocity and backwash process what are operating characteristics of tubular membrane can be stable CMP wastewater treatment. But when the coagulant and tubular membrane are used at the same time, the withdraw and treatment of the CMP wastewater are possibile. However further treatment process needs if treated water will be used for semiconductor fabrications.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.4
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• pp.121-129
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• 2011

Hydrocarbons which are the main sources of VOCs from motor vehicles are emitted not only from the engine exhaust gas but also from evaporation of the fuel in storage and supplying systems. Evaporative emissions from gasoline fuel systems could be classified by diurnal, hotsoak and running loss. Diurnal loss test procedures are different as countries. Korea introduced new evaporative regulation in 2009 with 24hour VT-shed test procedure and relaxed emission standards. The estimations on different test procedures in this study show that the new Korean regulation get a little more severe than before and the 2 day diurnal loss test of U.S. is the most severe. So the test procedures as well as the stronger standards should be considered in the next evaporative emission regulation to reduce VOCs from motor vehicles. The important parameters to affect evaporative emissions are air and fuel temperature and fuel vapor pressure. Diurnal loss increases exponentially as rising air temperature and vapor pressure. The effects of vapor pressure on running loss are different as the capacities of canisters. Tests with simulating real temperature and driving conditions show that hydrocarbons in evaporative emissions could be more than those in exhaust gas in summer season because of the higher air temperature.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.365-370
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• 2006

This study was performed to determine the adsorption-desorption characteristics of polyhexame-thyleneguanidine phosphate in three different soil types of textural classification. Adsorption and desorption studies is impotent for prediction their fate and generating essential information on the mobility of chemicals and their distribution in the soil, water and air of our biosphere. The detection limit of the test substance quantified by a spectroscopic method using Eosin indicator was $0.25{\mu}g/mL$. The reproducibility of analytical method was confirmed by the preliminary test. The concentrations of polyhexamethylenequanidine phosphate in aqueous solution were $1.36{\pm}0.09,\;2.45{\pm}0.01,\;and\;$4.25{\pm}0.05{\mu}g/mL$ by a spectroscopic method using Eosin indicator. The adsorption percents of polyhexamethylenequanidine phosphate in soil were greater than 95.2% for all three test soils. The desorption percents from the adsorbed soil were less than 4.5, 4.7 and 4.7%. Therefore, the adsorption coefficient (K) were greater than 110, 111 and 116. The adsorption coefficient calculated as a function of the organic carbon content (Koc) of the test soils were greater than 9,181, 11,100, and 8,942, respectively. Therefore, the test substance, polyhexamethylenequanidine phosphate could be concluded as medium or high adsorption (>25%) and poorly desorption (<75%) in soil media. Therefore, this chemical is likely to be retained in soil media and may not pose a risk in the aquatic environment.

• Structural Engineering and Mechanics
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• v.19 no.6
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• pp.653-677
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• 2005

Concrete filled steel tubular columns (CFT) are widely used in civil engineering works, especially in large scale of works because of high strength, deformation, toughness and so on. On the other hand, as a kind of strengthening measure for seriously damaged reinforced concrete piers of viaduct in Hansin-Awaji earthquake of Japan in 1995, reinforced concrete piers were wrapped with steel plate. Then, a new kind of structure appeared, that is, reinforced concrete filled steel tubular column (RCFT). In this paper, compression test and bending-shearing test on RCFT are carried out. The main parameters of experiments are (1) strength of concrete, (2) steel tube with or without rib, (3) width-thickness ratio and (4) arrangement of reinforcing bars. According to the experimental results, the effect of parameters on mechanical characteristics of RCFT is analyzed clearly. At the same time, strength evaluation formula for RCFT column is proposed and tested by experimental results and existed recommendations (AIJ 1997). The strength calculated by the proposal formula is in good agreement with test result. As a result, the proposed evaluation formula can evaluate the strength of RCFT column properly.

• Journal of People, Plants, and Environment
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• v.22 no.6
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• pp.563-573
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• 2019

The North Korean government conducted its first nuclear test in 2006 and more recently the sixth nuclear test on September 3, 2017. In order to identify how North Korea's nuclear tests have affected the environment, a scientific approach is required. Although North Korea's nuclear tests and their environmental destruction are not a severe threat to the environment of the Korean Peninsula at this time, identifying environmental damage and taking countermeasures in advance are essential to minimize their potential threats to the environments. The purpose of this study is to study the environmental impact of North Korea's nuclear tests using Google Earth image analysis. As a method of the study, we compare Google Earth images taken before and after each nuclear test was conducted in North Korea. To overcome limitations of the suggested comparison method, we cross-checked our results with those of previous scientific research. After the 1st-3rd nuclear tests, green spaces were found to be considerably reduced. In particular, when comparing the Google Earth images before and after the second nuclear test, some ground subsidences were observed. Such subsidences can cause tunnels on the mountainsides and cracks in rocks around the mountains, leading to the release of radioactive materials and contaminating groundwater. Besides, after the 4th-6th nuclear tests, decay and deforestation were observed not in the nuclear test sites, but in their surrounding areas. Especially after the 5th and 6th nuclear tests, the topography and the forests of the surrounding areas were severely damaged. In relation to North Korea's nuclear tests and their impact on the natural environment, we need to prepare various policy measures to reduce North Korea's environmental pollution and natural environment destruction. Those policy measures include the establishment of various cooperative governance between the Korean government, the private sector, the academia, NGOs, and international organizations.

• Journal of the Korean GEO-environmental Society
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• v.13 no.12
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• pp.75-79
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• 2012

In the recycling of industrial waste unlike household waste, the legislation and the governmental systematic support, etc. were not also established due to an anxiety of hazard or harmfulness, etc. and a preconception. So the legislation and the system should be urgently established for the recycling of industrial waste. In this study, the environmental analyzing method of industrial waste-mixed coal ash in ash pond to recycle as a construction material is suggested by considering and analyzing test process and results about environmental impact factors of mixed coal ash. It is certified that there are not environmental problems in the recycling of mixed coal ash in ash pond as a construction material, according as its classification is general waste and each corresponding item of the leaching test result are satisfied with the 'environmental safety criteria' suggested in this study. And to build database, it is necessary to survey the environmental impact on surrounding areas with time after its recycling as a construction material.