• Korean journal of applied entomology
• /
• v.42 no.3
• /
• pp.225-231
• /
• 2003

The susceptibility of the different larval stages of Spodoptera litura to nine insecticides was evaluated using the perilla leaf-dipping method. Median lethal concentration ($LC_{50}$) was increased with larval development in the range of 0.5 ppm to 5.6 ppm, 9.9 ppm to 27.9 ppm, 9.6 ppm to 125.1 ppm and 24.3 ppm to 546.6 ppm in the 1st, 2nd, 3rd and 4th instar, respectively. The tolerance ratio (TR), which is the TR of 90 percent lethal concentration (LC/ sub 90/) to the recommended concentration, was 0.04 to 0.8 in the 1 st, 0.2 to 7.5 in the 2nd, 0.7 to 115.3 in the 3rd and 1.2 to 485.4 in the 4th instars. Lower D$LC_{50}$ and DTR, which is the difference between the $LC_{50}$ and the TR of 4th and other instars, respectively, were observed in chlorfenapyr, chlorpyrifos and EPN while higher ones were lufenuron, chlorfluazuron and teflubenzuron. These results mean that insecticides with lower D$LC_{50}$ and DTR are effective in controlling larva of S. litura collected in Milyang, Korea.

• Journal of Environmental Health Sciences
• /
• v.15 no.2
• /
• pp.97-106
• /
• 1989

This experiment was performed to study the acute toxic effects of mereuric chloride(HgCl$_{2}$) in goldfish (Carassius aurams). In the study, Lc$_{50}$ values were determined for each 24, 48, 72 ,and 96-hr and mercury bioassay during the tests were performed. in five parts gill, kidney, liver, muscle and egg. The results isummarized were as follows 1. In the range of acute lethal toxicity for goldfish was 0.15-1.50 mg/l and the Lc$_{50}$ values decreased with exposure time. 2. The Lc$_{50}$ values of HgCl$_{2}$ for goldfish at 24, 48, 72 and 96 hour were 0.64, 0.53, 0.46, and 0.39 mg/l, respectively. 3. In the 400 $\mu$g/l treatment group, the average levels of mercury residues in the gill, kidey, liver, muscle and egg during 96 hour were 107.02 $\mu$g/g, 8.65 $\mu$g/g, 6.87 $\mu$g/g, 0.61 $\mu$g/g, and 0.82 $\mu$g/g, respectively. 4. The mercuny residues of gill was up to 12-175 times greater than mercury contents found in the other tissues.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2005.12a
• /
• pp.124-126
• /
• 2005

Aquatic ecotoxicity of bisphenol A, a well known endocrine disrupter in mammals, was studied using lab. reared Daphnia magna as a test organism. The static acute 48h $LC_{50}$ of bisphenol A was 12.9mg/L and 110-hr $LC_{50}$ values of bisphenol A for daphnid embryos of different ages after deposition into the brood chamber increase with ages in the range of 1.55mg/L-8.91mg/L. Bisphenol A showed the ability to inhibit embryonic development. The lethal response and developmental inhibition all showed good concentration-response relationship.

• Journal of Environmental Impact Assessment
• /
• v.17 no.6
• /
• pp.381-391
• /
• 2008

The instances of the damage to livestock are increasing with frequent environmental disputes on the noise and vibration. This study analyzed 134 open cases dealing with the environmental disputes on livestock damaged by noise and vibration, and being intervened by National Environmental Dispute Resolution Commission. The environmental disputes on the noise and vibration account for 86% of all the disputes, and cases of the consequent damages to livestock have increased. As shown in the 134 cases, pig is the most lethal livestock attacked by the noise and vibration. During last 10 years, 89% of the noise damages hurting the livestock resulted from the noises pertaining to construction and 58% was due to the noise damages from the road constructions. The noise levels in the range of 70~80 dB(A) and the vibration levels of 70~75 dB(V) caused most of the disputes. The average rate of reimbursement for the livestock damages for the last 10 years was higher than the average rate of reimbursement of the total disputes intervened by National Dispute Resolution Commission.

• Korean Journal of Microbiology
• /
• v.5 no.1
• /
• pp.1-6
• /
• 1967

The environmental effects on radio-sensitivities of Lactobacillus and Saccharomyces cerevisiae were studied; Liquid suspensions of Lactobacillus and yeast were gamma-irradiated under various conditions; temperatures, hydrogen ion concentrations, amino acids and vitamins were treated seperately with variations of concentrations. (shown in figures) It is found that simultaneous heat treatment is effective to sterilize microorganisms than pre after treatment, and concentration of hydrogen ion does not affect the lethalty of yeast but or Lactobacilli was affect at the range of pH. 5.0 to 7.0. Ascorbic acid, thiamin and pyridoxine were protective dependently against lethal action of gamma-ray and its protective effects increase with the increasings of concentrations. Glutamic acid, aspartic acid, tyrosine and phenylalanine were proved to be protective for both strains at 0.1 between 1.0 percent. It can be suggested that industrial sterilizing doses of irradiation by gamma-ray for food should be applied more than those dose of saline or buffer suspension, because natural food stuffs are rich of vitamins and amino acids.

• YAKHAK HOEJI
• /
• v.45 no.4
• /
• pp.347-351
• /
• 2001

A rapid and sensitive method for the determination of glyphosate, a phosphated amino acid herbicide, in whole blood is presented. After removal of protein, the whale blood was purified by using the anion exchange resin (Dowex 1), and derivatized with 9-fluorenylmethyl chloroformate (FMCL). Derivatized glyphosate from blood sample was injected onto a Whatman partisil 10SAX column and separated with 0.1M phosphate buffer (pH 2.5) and acetonitrile (ratio=3:1). The high performance liquid chromatography-fluorescence detection gave the detection limit of 86pg and linearity of 0.9999 in the range of 0.25 $\mu$g/ml and 25 $\mu$g/ml. The recoveries of glyphosate added to the blood samples were ranged from 75.3% to 100.4% compared to the samples prepared in water. The derivatized glyphosate was stable at various acidity and temperature. This method has been successfully applied to the blood samples of lethal intoxication with the herbicide glyphosate.

• Journal of the Korea Safety Management & Science
• /
• v.16 no.2
• /
• pp.43-52
• /
• 2014

In weapon systems development, live fire tests have been frequently adopted to evaluate the performance of the systems under development. Therefore, it is necessary to ensure safety in the test ranges where the live fire tests can cause serious hazards. During the tests, a special care must be taken to protect the test and evaluation (T&E) personnel and also test assets from potential danger and hazards. Thus, the development and management of the range safety process is quite important in the tests of guided missiles and artillery considering the explosive power of the destruction. Note also that with a newly evolving era of weapon systems such as laser, EMP and non-lethal weapons, the test procedure for such systems is very complex. Therefore, keeping the safety level in the test ranges is getting more difficult due to the increased unpredictability for unknown hazards. The objective of this paper is to study on how to enhance the safety in the test ranges. To do so, an approach is proposed based on model-based systems engineering (MBSE). Specifically, a functional architecture is derived utilizing the MBSE method for the design of the range safety process under the condition that the derived architecture must satisfy both the complex test situation and the safety requirements. The architecture developed in the paper has also been investigated by simulation using a computer-aided systems engineering tool. The systematic application of this study in weapon live tests is expected to reduce unexpected hazards and test design time. Our approach is intended to be a trial to get closer to the recent theme in T&E community, "Testing at the speed of stakeholder's need and rapid requirement for rapid acquisition."

• Korean Journal of Ichthyology
• /
• v.30 no.3
• /
• pp.131-136
• /
• 2018

Decrease in seawater temperature during winter is one of the most important and serious issues confronted by fish net-cage aquaculture farms. This can become the cause of the manifestation of diseases and ensuing mass mortality. The present study was conducted to assess the survival rate, the range of limited low-temperature, the response of oxidative stress in the blood of red sea bream Pagrus major with decrease of water temperature. Low-lethal temperature for 7 days of P. major ($7day-LT_{50}$) was $6.54^{\circ}C$ (confidence limit: $6.31{\sim}6.71^{\circ}C$). Oxygen consumption rate was decreased with lower temperature. It showed the minimum value at the range of low-lethal temperature. Osmolality at $5^{\circ}C$ and $6^{\circ}C$ experimental group was higher significantly than control group. SOD (superoxide dismutase) activity was increased significantly at $5^{\circ}C$ experimental group compared to control group. This study data will be used to determine the appropriate area for aquaculture of red sea bream. It also manage fish net-cage farm to cope with the mass mortality occurring frequently during winter season.

• Progress in Medical Physics
• /
• v.5 no.2
• /
• pp.35-43
• /
• 1994

Electromagnetic wave may induce effect and damage on the bio-body, either by electric fields of magnetic fields. We measure electrophysiological changs in rabbit's brain exposed to 2.45GHz micro wave(power density 40mW/cm$^2$) which distance 30cm from the source. In order to process the bio-electrical signal (EEG), used pre-amplifier module with self-made and Digtal analyzer computer system. Spectal analysis of the EEG showed variable power in the frequency range(1～30Hz) through each exposure time(10min, 20min, 30min) before and after. In effectively measured by the bio-electrical signal processing and can found threshold of minmal permissible exposure and lethal exposure.

• Toxicological Research
• /
• v.25 no.2
• /
• pp.107-111
• /
• 2009

The alcohol extract of the larvae of Bombus ignitus, otherwise known as the Bumblebee, was orally administered to rats at doses of 0, 0.04, 0.2, 1 or 2 g/kg as a single oral dose. There were no observed clinical signs or deaths related to treatment in all the groups tested. Therefore, the approximate lethal dose of the alcohol extract of B. ignitus was considered to be higher than 2 g/kg in rats. Mild decreases in body weight gain in male rats were observed dose-dependently within the B. ignitus treated groups over 2 weeks. Throughout the administration periods, no significant changes in diet consumption, ophthalmologic findings, clinical pathology (hematology, clinical chemistry and coagulation) or gross pathology were detected. Minor changes in male rats were found with in the hematological parameters in groups treated with the 0.04 g/kg, 1 g/kg or 2 g/kg of B. ignitus larvae extract, however, all the changes observed were within the physiological range. From these results, it was concluded that there was no evidence of specific toxicity related to the ingestion of alcohol extract of B. ignitus larvae.