• Journal of Applied Reliability
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• v.16 no.2
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• pp.90-97
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• 2016

Purpose: Majority of bridges and roads in Gangwon Province have been carrying loads associated with heavy materials such as rocks, mining products, and cement. This location-specific live loads have contributed to the present situation of overloading, compared to other provinces in Korea. However, the bridges in Gangwon province are designed by national bridge design specification, without considering the location-specific live load characteristics. Therefore, this study focuses on the real traffic data accumulated on regional weighing station to verify the live load characteristics, including actual live load gross vehicle weight, axle weight axle spacings, and number of trucks. Methods: In order to take into account the location specific live load, a governmental weigh station (38th national highway Miro) have been selected and the passing truck data are processed. Based on the truck survey, trucks are categorized into 3 different shapes, and each shape has been idealized into normal distribution. Then, the resulting survey data are processed to predict the target maximum live load values, including the axle loads and gross vehicle weights in 75 years service life span. Results: The results are compared to the nationally used DB-24 live loads, and the results show that nationally recognized DB-24 live load does not sufficiently represent real traffic in mountaineous region in Gangwon province. Conclusion: The comparison results in the recommendation of location-specific live load that should be taken into account for bridge design and evaluation.

• Journal of Oriental Neuropsychiatry
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• v.23 no.2
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• pp.121-128
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• 2012

Objectives : This research investigates the single oral dose toxicity of ACM in SD rats. Methods : ACMs were administered to female and male SD rats, as an oral dose of 5000 mg/kg. Animals were monitored for the mortality and changes in the body weight, clinical signs and gross observation during the 14 days after dosing, upon necropsy. Results : We could not find any mortality. Compared with the control group, significant weight change was not observed in the experimental group. First day after administration, compound-colored stool was observed in all rats. After the second day of administration, the more common symptoms were not observed. There were no gross abnormalities in all cases. [ED NOTE: highlight: given the context, this is very vague] Conclusions : The results obtained in this study suggest that the approximate lethal dose of ACM in both female and male rats were considered as over 5000 mg/kg.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.160-162
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• 2017

When rubber elastomer has contact with fuel, since the component and additive having low molecular weight can flow out, the physical properties of both elastomer and fuel could be hindered. In order to predict the life of the rubber elastomer, this study is to determine the change of weight, thickness, hardness, strain, and compression set as mechanical properties of the sealant rubber O-ring, which was dependent on volume, temperature, and storage time of the contacted fuel. We also determined purity of fuel via GC analysis and measured gross heat of combution. The results could be used as a reference to evaluate the life of the rubber elastomer.

• Toxicological Research
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• v.27 no.4
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• pp.217-224
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• 2011

The object of this study was to evaluate the single oral dose toxicity of platycodin D, a saponin from the root of Platycodon grandiflorum in male and female mice. Platycodin D was administered to female and male mice as an oral dose of 2000, 1000, 500, 250 and 125 mg/kg (body wt.). Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after treatment, upon necropsy, organ weight and histopathology of 14 principle organs were examined. As the results, no platycodin D treatment related mortalities, clinical signs, changes on the body and organ weights, gross and histopathological observations against 14 principle organs were detected up to 2000 mg/kg in both female and male mice. Therefore, $LD_{50}$ (50% lethal dose) and approximate LD of playtcodin D after single oral treatment in female and male mice were considered over 2000 mg/kg - the limited dosages recommended by KFDA Guidelines [2009-116, 2009], respectively.

• Journal of Korean Medicine for Obesity Research
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• v.17 no.2
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• pp.96-100
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• 2017

Objectives: Samjung-hwan (SJH) is a Korean herbal formula that has been used for antilipidemic, antioxidant, and antidepressant effects. As a part of safety evaluation, single oral dose toxicity study of modified SJH in Sprague-Dawley (SD) rats was carried out. Methods: Modified SJH extract was administered orally in male and female SD rats at dose of 5,000 mg/kg. After single oral administration of modified SJH, we monitored the changes of mortalities, clinical signs, and body weight daily for 14 days. Gross necropsy findings were also evaluated at the end of the experiment. Results: Modified SJH extract did not induce any toxic signs in the changes of mortalities, clinical signs, and body weight. There were also observed no gross necropsy findings in rats. Conclusions: As results, the approximate lethal dose of modified SJH extract in SD rats was considered to be over 5,000 mg/kg. This suggests that modified SJH is safe herbal formula for the treatment with.

• Toxicological Research
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• v.23 no.1
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• pp.65-72
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• 2007

This study was conducted to obtain information of the oral dose acute toxicity of PGB-2, a novel polyglucosamine polymer produced from Citrobacter sp. BL-4 (a new strain) in male and female mice. Mortality, body weight changes, clinical signs were monitored during 14 days after single oral dose of test article at dose levels of 2000, 1000, 500, 250 and 125 ml/kg. Gross lesions, organ weight and histopathology of principal organs were examined after necropsy. As the results, we could not find any mortalities, clinical signs, changes in the body weight and gross findings except for white foci in the liver. In addition, no PGB-2-treatment related abnormal changes on the organ weight and histopathology of principle organs were detected except for atypical signs of liver. White liver foci were confirmed as focal infiltration of inflammatory cells. The results suggest that the PGB-2 is relatively safe in mice but the possibility of hepatotoxicity could not be excluded. The $LD_{50}$ and approximate LD in mice after single oral dose of PGB-2 were considered over 2000 mg/kg, respectively. In future, the potential hepatotoxicity of PGB-2 should be evaluated through the repeat dose toxicity test prior to develop as a new agent.

• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.395-400
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• 2001

The present study analyze the morphological aspects of the cerebrum of mice with prenatal exposure to high and low dose (0.5, 1, 2 Gy) of $\gamma$-radiation on gestation day 12 or 16. The animal were allowed to give birth and the offspring were sacrificed at postnatal days 28 for gross and microscopic examination of cerebrum. Their body weight, brain weight, brain length, brain width, cortical thickness and area of cingulum bundle were examined. The histological and planimetric analysis were performed observing coronal sections. The gross malfomation (microcephaly) and abnormality of cortical architecture were prominent after exposure to 2 Gy on day 12 of gestation. significant dose-related reductions in body weight, brain weight, brain size were found in all irradiated groups. A significant change was found in thickness of the cerebral cortex and area of the cingulum bundle in the groups exposed to 0.5 Gy or more. There was no difference a lamina patter of six layers in cerebral cortex between the control and irradiated groups, but cell packing density increased significantly in the group exposed to 1 Gy or more. These results suggested that dose as low as 0.5 Gy could cause a morphologically reduce change in developing mouse cerebrum and exposure on day 12 of gestation to $\gamma$-irradiation is a particularly sensitive phase in causing malformation and abnormality of central nerve system.

• The Journal of Internal Korean Medicine
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• v.34 no.4
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• pp.349-361
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• 2013

Objectives : This study aimed to evaluate the single oral dose toxicity and four weeks repeated dose determination of Gamisasangja-tang (GST) in male and female Sprague-Dawley rats. Methods : In the single oral toxicity study, rats were orally administered a single dose of 0 and 5,000 mg/kg GST. There were 5 rats in each group. After single administration, mortality, clinical signs, body weight changes and gross pathological finding were observed for 14 days. In the 4-weeks repeated oral dose determination study, rats were orally administered a single dose of 0, 1,250, 2,500 or 5,000 mg/kg GST. There were 5 rats in each group. Mortality, clinical signs, body weight changes, food consumption and gross pathological finding were observed for 28 days. Organ weight, clinical chemistry and hematology were tested after 28 days. Results : There was no mortality in either of the two studies. There were also no significant differences in clinical sign, body weight, organ weights, hematological or serum chemical parameters between the GST and control groups. Conclusions : The results obtained in this study suggest that the 50% lethal dose of GST is over 5,000 mg/kg, so this finding would be expected to provide scientific evidence for the safety of GST.

• Toxicological Research
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• v.28 no.1
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• pp.11-18
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• 2012

The aim of this study was to evaluate the single oral dose toxicity of Bupleuri Radix (BR) aqueous extracts, it has been traditionally used as anti-inflammatory agent, in male and female mice. BR extracts (yield = 16.52%) was administered to female and male ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 14 principal organs were examined. As the results, no BR extracts treatment related mortalities, clinical signs, changes on the body and organ weights, gross and histopathological observations against 14 principal organs were detected up to 2,000 mg/kg in both female and male mice, except for soft feces and related body weight decrease detected in male mice treated with 2,000 mg/kg. Therefore, $LD_{50}$ (50% lethal dose) and approximate LD of BR aqueous extracts after single oral treatment in female and male mice were considered over 2000 mg/kg, respectively. Although it was also observed that the possibilities of digestive disorders, like soft feces when administered over 2,000 mg/kg of BR extracts in the present study, these possibilities of digestive disorders can be disregard in clinical use because they are transient in the highest dosages male only.

• Fire Science and Engineering
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• v.30 no.6
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• pp.1-8
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• 2016

In cars, the amount of combustibles, such as plastics, textiles, etc., have increased dramatically to improve the fuel efficiency of cars by reducing the gross vehicle weight according to the increases in an oil price and to reduce environmental problems. One or two cars were involved in a parking lot fire prior to the mid-2000 s. On the other hand, there were many parking lot fires where the entire car was destroyed due to increasing the use of plastics. In this study, the quantity of combustibles in a car was 316.2 kg over a total weight 1935 kg. This is 16.34% of total weight and 10 times greater than that three decades earlier. When a sprinkler is installed as a parking lot fire protection system as a substitute for water spray, the water discharge of the sprinkler must maintain the original density of water spray, $20lpm/m^2$. In addition, the use of a hose reel $CO_2$ system at pilotis parking lots must be prohibited because the hose reel $CO_2$ system has no adaptability for a car fire. Instead, this study proposes foam, dry powder, loaded stream systems be used in parking lot fire suppression systems.