• Journal of the Korean Society of Safety
• /
• v.29 no.6
• /
• pp.68-75
• /
• 2014

It is very important to classify explosion hazardous area (EHA) suitably and to use proper explosion-proof electric installations for facilities using flammable gases and liquids. In the past, various examples in the Notification of Ministry of Employment and Labor were referred to in classifying EHA. But, at present, many companies use the hypothetical volume in Korean Standards (KS). This study reviews the validity of EHA classification based on the hypothetical volume by comparing the calculated radii of EHA with those obtained by a consequence analysis program called PHAST and a mathematical approach in British Standards (BS). The radii of EHA by the hypothetical volume were found to be slightly larger than those by the other two methods. This was attributed to rather conservative uses of a safety factor(k) and a correction factor(f) for availability of ventilation in calculating the hypothetical volume. Since the differences are not so conspicuous, however, it is concluded that the hypothetical volume in KS is a valid means for the classification of EHA. This study also presents a table of the radii of EHA for easy reference by small-scale companies using city gas, C3-LPG and flammable liquid(toluene), respectively. The table consists of 25 leakage scenarios corresponding to combinations of 5 pipe(nozzle) sizes and 5 operating conditions for each flammable gas and liquid.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.8
• /
• pp.1059-1067
• /
• 2013

Automotive fuel tank is generally divided into two parts: main frame and assembly parts. While the car is running, valves are used to prevent liquid carry over and to discharge evaporated gas from the fuel tank. However, current fuel tank designs focus on the gas ventilation or secured location. In this study, the location of the parts used to prevent liquid carry over within the fuel tank is evaluated during an optimal design process. To develop this design process, an approximate optimization is applied. Through the optimal design process, the optimal valve location in fuel tank is determined and the approximate optimization is validated by the Taguchi method. Finally, the optimized valve location is used to reduce the development cost and time and to contribute toward improved automobile quality owing to enhanced reliability.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.6 no.1
• /
• pp.52-56
• /
• 2008

Amitraz is used as farm-animal insecticide. Its side effects in humans are related to its pharmacological activity on alpha 2-adrenergic receptors. The case describes a previously healthy 46-year-old woman who intentionally ingested approximately 250mL of liquid amitraz. She presented with vomiting, altered mental status, miosis, dry mouth, hypopnea, metabolic and respiratory acidosis, hypotension, hypothermia, polyuria, metabolic acidosis, elevated serum aminotransferase and abdominal distension. Supportive treatments including mechanical ventilation, hydration, dopamine infusion, bicarbonate infusion and gastric decompression resulted in improvement. By hospital day 3, she recovered with resolution of abdominal distension. It is paramount to recognize amitraz poisoning when a pesticide-intoxicated patient presets with signs and symptoms consistent with organophosphate intoxicated patients but with greater alpha 2-adrenergic related symptoms such as decreased bowel motility and xerostomia.

• Journal of Advanced Marine Engineering and Technology
• /
• v.29 no.5
• /
• pp.488-494
• /
• 2005

The ejector is used to obtain a vacuum state, and it has been applied to a lot of industry field such as a heat engine, a fluid instrument power plant. a food industry, an environment industry etc., because there is no problem even it is mixed with any kind of liquid, gas. and solid. The flow characteristics in the ejector was investigated by a PIV and a CFD. The agreement between numerical analysis and experiment shows the validity of this study and the results of this study would be useful to the engineers who design for the flow systems for heating. ventilation. air conditioning and wastewater purification plants.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.2
• /
• pp.305-311
• /
• 1993

A total of thirty male Holstein calves were reared outdoors with simple housings or in warmed pens in three experiments conducted in three consecutive midwinters in Hokkaido. Average outdoor air temperatures during the experiments were between -5.3 and $-6.1^{\circ}C$, and average minimum air temperatures were between -9.7 and $-10.6^{\circ}C$. The age of calves at the start of the experiments were $16{\pm}6$ hours. There was no difference in the liquid feed intake, while the solid concentrate (artificial milk) intake by the calves in the simple housing systems (outdoors, calf hutch and open shed) tended to be higher than those in the warmed pen. No significant differences in the daily gain or the monthly development of wither height were observed among housing systems. There were no serious cases of diarrhea. However, coughing was observed in several of the calves reared in the poorly ventilated warmed pens.

• Plant Resources
• /
• v.4 no.3
• /
• pp.200-205
• /
• 2001

It was reported in our Previous paper that the fermented products from Gloeostereum incarnatum strongly inhibit the growth of six kinds of bacteria in human bodies. In this paper the appropriated conditions of immersing culture for the strain 8 903 of Gloeostereum incarnatum was analysed. And the output of the hypha and fermentative product was determined or compared. The prelimenaryresults showed that the appropriated conditions for the growth of Gloeostereum incarnatum are: (1)culture medium:glucose 3%; protein peoptne 0.2%; soybeancake power 1% yeast power 0.3%; KH2PO40.05%; MgSO4 0.03%; CaCO3 0.01%; vitamin Bl 0.001%; befor sterilization pH Value of six should be maintained; (2) temperature; 27f ~28f ; (3) time; about 200 hours; (4) ventilation; (30%∼50%)/min. The sigh of the end culture are: pH coming down about 4: remnant glucoses less 1%; amino nitrogens about 20%; time about eight days. In the aforementioned conditions, the output of fermentative product achieve to 2.5∼3g/L.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.5 no.2
• /
• pp.123-125
• /
• 2007

Amitraz is a formamidine-derived insecticide and acaricide which is commonly used throughout the world. Amitraz intoxication is mediated through ${\alpha}_2$ adrenergic receptor agonist effects, similar to those of the ${\alpha}_2$ agonist clonidine. We report a case of a patient who experienced coma and hypotension after amitraz ingestion. A 37-year-old woman visited the ER with symptoms of vomiting and altered mental state. She had ingested a mouthful of liquid amitraz concentrate (12.5%), which rapidly led to vomiting, hypotension, bradycardia, hyperglycemia, and mental stupor. Supportive treatment, including mechanical ventilation and administration of inotropics, resulted in full recovery within four days.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2001.11a
• /
• pp.74-82
• /
• 2001

It was reported in our Previous paper that the fermented products from Gloeostereum incarnatum strongly inhibit the growth of six kinds of bacteria in human bodies. In this paper the appropriated conditions of immersing culture for the strain 8 903 of Gloeostereum incarnatum was analysed. And the output of the hypha and fermentative product was determined or compared, The prelimenaryresults showed that the appropriated conditions for the growth of Gloeostereum incarnatum are: (1)culture medium:glucose 3%; protein peoptne 0.2%; soybeancake power 1%, yeast power 0.3%; KH2PO40.05%; MgSO4 0.03%; CaCO3 0.01%; vitamin Bl 0.001%; befor sterilization pH Value of six should be maintained; (2) temperature; 27$^{\circ}C$～28$^{\circ}C$; (3) time; about 200 hours; (4) ventilation; (30%～50%)/min. The sigh of the end culture we: pH coming down about 4: remnant glucoses less 1%, amino nitrogens about 20;, time about eight days. In the aforementioned conditions, the output of fermentative product achieve to 2.5 ～3g/L.

• Tuberculosis and Respiratory Diseases
• /
• v.48 no.2
• /
• pp.223-235
• /
• 2000

Background: Liquid ventilation is associated with decreased inflammatory response in an injured lung. This study was performed to investigate if whether perfluorocarbon(PFC) can decrease chemokine expression in airway epithelial cells. Methods: A549 cells were used for airway epithelial cells and perfluorodecalin for PFC. To expose cells to PFC, lower chamber of Transwell$^{(R)}$plate was used. This study was performed in two parts. In the first part, we examined whether PFC could decrease chemokine expression in airway epithelial cells through inhibition of other inflammatory cells. Peripheral blood mononuclear cells(PBMC's) were isolated and stimulated with lipopolysaccharide(LPS, 10 ${\mu}g/mL$) for 24 hours with or without exposure to PFC. Then A549 cells were stimulated with conditioned media(CM) containing the culture supernatants of PBMC. After 24 hours, the expressions of interleukin-8(IL-8) and RANTES were measured. In the second part of the study, we studied whether PFC could directly suppress chemokine expression in airway epithelial cells. A549 cells were stimulated for 24 hours with interleukin-l$\beta$ and/or tumor necrosis factor-$\alpha$ with or without exposure to PFC, and then the chemokine expression was measured. Northern analysis was used to measure the mRNA expression, and ELISA was used for immunoreactive protein measurements in culture supernatant. Results: 1. IL-8 and RANTES mRNA expression and immunoreactive protein production were increased significantly by CM from LPS-stimulated PBMC in A459 cells compared to with CM from unstimulated PBCM (p<0.05), but exposure of PFC had no significant effect on either mRNA expression or immunoreactive protein expression. 2. IL-8 and RANTES mRNA expression and immunoreactive protein production were increased significantly by IL-1$\beta$ and TNF-$\alpha$ in A549 cells(p<0.05), but exposure of PFC had no significant effect on neither either mRNA expression nor immunoreactive protein production. Conclusion : Decreased chemokine expression of airway epithelial cells may not be involved in decreased inflammatory response observed in liquid ventilation. Further studies on possible mechanisms of decreased inflammatory response are warranted.

• Journal of the Korean Institute of Gas
• /
• v.26 no.6
• /
• pp.1-8
• /
• 2022

With the development of the chemical industry, related accidents frequently occur, and fire and explosion accidents account for a large proportion. In order to prevent fire and explosion accidents, places that handle flammable liquids are classified according to the Korean Industrial Standards (KSC IEC60079-10-1) in accordance with the relevant laws. The same applies to laboratories dealing with flammable liquids. This paper verified the applicability of the procedure for classifying explosion hazard areas according to the Korean Industrial Standards when flammable liquid release from the laboratory to form an evaporative pool, and also verified the effect of a change in ventilation speed on the release characteristics. Through this, it was found that it was difficult to apply the criteria for the classification of places at risk of explosion according to the Korean Industrial Standards, and special safety measures should be prepared.