• Journal of Aerospace System Engineering
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• v.14 no.3
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• pp.24-31
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• 2020

A study on the H2O2 based low toxic hypergolic propellant was conducted. The fuel candidates were chosen as a mixture of Amine solvent and reactive additive. The analytical performance was calculated via the NASA CEA code and 96% Isp of the NTO/UDMH was confirmed. The ignition delay measurement with drop test was performed and all candidates showed less than 10 ms in the best performance cases. Based on these results, the feasibility of high response H2O2 based low toxic hypergolic propellant was confirmed.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.7-16
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• 2012

Combustion Toxic Effects among several factors of risk encountered during fire are important in the evacuation and final survival, and they are broader and fatal than the direct damages caused by flame. Most studies on fire toxicity until the present are limited to fatality, mainly deaths by fire through pathological research. In this study, it is conducted as a fundamental experiment to address 3 principles of animal experiment and to provide an alternative test to animal testing that is regulated by national building codes and it was conducted through approval by the animal testing ethics committee. Hence, in this study average time of activity stop was measured after directly inhaling toxic gases (HCN) to laboratory animals (mice) through gas toxicity test (KS F 2271) for major asphyxiating gases(HCN) which are produced during fire combustion. effects of Combustion toxic gases on body were quantitatively analyzed through changes in internal organs and hematological analysis, and electrophoresis of a single cell of these laboratory animals. Biological conclusion of combustion toxicology is drawn through approaches (pathological examination, blood test, blood biochemical test, electrophoresis analysis of single cell) which could not confirmed in existing gas toxicity test.

• Korean Journal of Pharmacognosy
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• v.50 no.3
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• pp.205-218
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• 2019

This study was conducted to investigate the toxicity symptoms and approximate lethal dose (ALD) of Oplopanax elatus (Nakai) Nakai hydrothermal extract powder by single oral dose toxicity and 4 weeks of repeated oral dose determination. The Sprague-Dawley (SD) male and female rats were treated with 1,250 (low- dosage group), 2,500 (medium- dosage group) and 5,000 (high- dosage group) mg/kg. In the single oral dose toxicity test, no dead animals and toxic symptoms were observed during the experiment. And there were no related with anomalies in normal weight changes and autopsy results. In the four-week repeated oral dose determination test, no death animals and toxicity symptoms were observed during the experiment, and there were no abnormal results in weight changes, feed and negative intake measurements. Results of eye examination, urinalysis, hematological values and serum biochemical values, gross findings and absolute organ were not of singularity. These result demonstrated that no toxic symptoms were observed by the test substance Oplopanax elatus (Nakai) Nakai hydrothermal extract powder under this test condition, and the non-toxic content is determined to be 5,000 mg/kg/day.

• Journal of Environmental Science International
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• v.4 no.2
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• pp.201-214
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• 1995

Design approach of upflow Anaerobic Sludge Blanket(UASB) process based on the biological kinetic parameters are known to be very difficult since the characteristics of the granular slut비e depends on the type of wastewater and size distribution of the granular sludge also depends on the upflow velocity in the UASB reactors. Furthermore, industrial wastewater containing toxic substances has been treated by UASB process without the clear knowledge of toxic effects on the granular slut형e. Hence, the present research was aimed on the intensive evaluation of biological kinetic parameters of the granular sludge in UASB reactor with and without toxic substance of 2, 4-dichlorophenol in order to present the basic design measures for UASB process design. The results could be summarized as follows. The biological kinetic parameters(k and Ks) considerably varied with the granular size of the sludge. Generally, 연e k and ks values of the granular sludge increased with the particle size of the granule. The biological kinetic parameters(k and Ks) of the granular sludge obtained from batch test were not applicable to design purpose of UASB process due to substrate diffusional limitation into the granular sludge in the completely mixed UASB reactors. The toxic effects on k and Ks greatly varied with the granular sixte. And as the toxicant concentration increased, the k value decreased while the Ks value increased. Inhibition constant(hi) for k with the toxicant of 2, 4-dichlorophenol varied from 0.5 to 2.3 depending on the granular sizes while the inhibition constant(Ki) for Ks varied from 20.7 to 80.1, showing the mixed inhibition.

• Journal of Society of Preventive Korean Medicine
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• v.3 no.2
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• pp.91-100
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• 1999

Today, toxicology is used for many purpose, in many fields. Classification of special toxic effect is related next 4 important principles. 1. The chemical substance must move to target organ or tissue that can induce Biological effect. For this movement, we have to understand the physical-chemical characteristic of substance, and the rout of absorption, metabolism, diffusion and excretion of toxic substance. 2. Every biological effect that induced by chemical substance is not harmful. For example, some specific chemical substance is not harmful in liver enzyme system. 3. The strength of biological effect induced by chemical substance is deep related with dose. Nearly all substance is not effective below the specific dose, and it may toxic to death over the specific dose. It is the 'Dose - response relationship' But carcinogen may toxic whether it is law dose or not. 4. The information that was obtained by experimental animal test, could have to adapt in human biology. Because biological effect of chemical substance could be different in every biological species. In past, drugs was obtained by animal or plants. But in the future, it could be obtained by biochemistry, and genome project. Therefore, in Oriental medicine, research and approach is needed at this time, and have to develop new method of experience in toxic method.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1098-1108
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• 2008

Batch type and column type experiments were performed in order to predict adsorption and movement within soil. Clay minerals montmorillonite and kaolinite were respectively added to paraquat which is a cationic compound with long residual time, 2,4-D which is an anionic compound with relatively short residual time and napropamide which is an amphoteric compound. Therefore, it is very important to determine the movements of toxic pollutants in the ground soil to establish measures to prevent soil grounds contamination and to restore contaminated soils effectively, because contamination of soil is getting severe due to these toxic wastes, industrial waste water, and agricultural chemicals, etc. Therefore, in this study, we have carried out column and batch experiments by using general toxic organic compounds as test samples in order to restore contaminated soils effectively as well as to prepare a basic data to develop absorbents that will remove various toxic organic compounds, with a grandiose purpose to prevent contaminations of soil and grounds due to various toxic organic compounds.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.437-441
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• 2008

A non-toxic Post Boost Stage(PBS) with LOX/Ethanol engine was successfully demonstrated at the Tomioka Facility of IHI Aerospace. IHI Aerospace has researched and developed the nontoxic propulsion systems and the LOX/Ethanol is one of the most attractive non-toxic bipropellant candidates. ${\rho}ISP$ of LOX/Ethanol is higher than ${\rho}ISP$ of the other non-toxic bipropellants as LOX/HC or $LOX/LH_2$. The authors studied the combustion characteristics of LOX/Ethanol propellant with the engine designed for LOX/LNG propellant. Also the injector with a built-in igniter was designed and examined its feasibility, ignition and combustion characteristics. We have demonstrated Post Boost Stage with future LOX/Ethanol engines. This propulsion system is targeted for expandable vehicle upper stage to accelerate delta-V to reach the required orbit. PBS Demonstration Model is designed as a test stand to evaluate feed system for integrated propulsion system and also to demonstrate Integrated Vehicle Health Management(IVHM) technique using local valve control and also valve behavior-monitoring capability.

• Journal of Environmental Science International
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• v.20 no.7
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• pp.811-818
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• 2011

Daphnia Magna Stratus has been widely accepted as useful species for estimating the toxicity of chemicals to aquatic invertebrate and recommended as species for the testing chemicals from the international guideline as well as Korean guideline. The study was performed for the acute toxicity test by using water flea(D. Magna) for effluents from several wastewater treatment plants and drainage canals in GyeongBuk area. Five heavy metals, 1,4-Dioxane and Perchlorate were tested. Most Toxicity Units(TU) of Industrial wastewater effluents were less than 1 which means effluent was not toxic to D. Magna. However, effluents containing 1,4-Dioxane and Perchlorate were significantly toxic to D. Magna. Therefore, facilities should reduce the 1,4-dioxane since new regulations will force them after the year of 2011.

• Fire Science and Engineering
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• v.27 no.5
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• pp.44-56
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• 2013

This research is to identify how much toxic combustion gases are produced from Korea standardized real fire test (Class A&B) by using Room Corner Tester (RCT) and how much those gases are possibly dangerous to testing personnel by estimating the level of carboxyhemoglobin (% COHb). It is confirmed that testing personnel can be affected as more than 40% COHb from Class A 9th and 10th rating in respiration minute volume (RMV) 2 and from Class A 5th to Class A 10th rating in RMV 3 during the time for initial three minutes. Also, in the case of Class B real fire tests, although it is considered rather safe for the initial 1 minute, testing personnel can be affected as more than 20% COHb from Class B 16th to 20th rating in RMV 3 during total test time. Currently, the Korea standard is only focusing on the protection measures against the heat, but the it is neglecting the protection measures against toxic combustion gases. Therefore, according to this study, it is strongly recommended that testing personnel should wear a self-contained breathing apparatus, or the equivalence depending on the real fire test rating.

• Environmental Analysis Health and Toxicology
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• v.11 no.3_4
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• pp.1-10
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• 1996

The purpose of this study was to characterise the subacute toxic potency of i.v. administered KHPC-005 and 006. Few test compounds-related toxic effects were observed in body weight gain, clinical signs, urinalysis, hematological parameters and serum biochemical values. Gross necropsy and histopathology revealed no evidance specific toxicity. Our data indicated that no-observed effect level of KI-IPC-005 and 006 were estimated to be 10mg/kg and 4mg/kg in male rats, and 10mg/kg and 1.33mg/kg in female rats, respectively.