• Journal of Marine Life Science
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• v.8 no.2
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• pp.150-159
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• 2023

To determine the toxic effects of the mirror carp, Cyprinus carpio nudus on waterborne nitric acid exposure, they were exposed to waterborne nitric acid at 0, 4, 20, 100, 500, and 2,500 mg NO₃^-/L for 96 h. The semi-lethal concentration (LC₅₀) of the scented fish by 96 hours of acute exposure to nitric acid was 1,433.54 mg NO₃^-/L. The physiological changes of waterborne nitric acid exposure on mirror carp were evaluated through hematologic properties, and RBC count showed a significantly decreased (p < 0.05). The change in the ion control ability of the mirror carp according to exposure to waterborne nitric acid was evaluated through the plasma inorganic component, and calcium and magnesium were significantly decreased (p < 0.05) in the plasma inorganic component. The health and stress status of the mirror carp due to exposure to waterborne nitric acid were evaluated through plasma organic ingredients, and the plasma organic component glucose showed a significantly increase (p < 0.05). Changes in liver damage and enzyme activity due to waterborne nitric acid exposure were evaluated through plasma enzyme components, the enzymatic activities of plasma AST, ALT, and ALP were significantly decreased (p < 0.05) in high levels of waterborne nitric acid exposure. The results of the present study suggest that waterborne nitric acid exposure to C. carpio nudus can toxicly affect survival, hematologic properties, and plasma components.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.373-379
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• 2017

Juvenile Paralichthys olivaceus (mean length $19.8{\pm}2.6cm$, mean weight $97.8{\pm}15.8g$) were exposed for 96 hours to different nitrate concentrations of 0, 62.5, 125, 250, 500, 1,000, and $1,500mg\;L^{-1}$ in biofloc and 0, 62.5, 125, 250, 500, and $1,000mg\;L^{-1}$ in seawater. Median lethal concentration values ($LC_{50}$, the concentration at which 50% of mortality occurred after 96 hours of exposure) of nitrate to P. olivaceus in biofloc and seawater were 1,226 and $597mg\;NO_3L^{-1}$ (P<0.05), respectively, revealing a higher toxicity of nitrate to P. olivaceus in seawater than in biofloc. In hematological parameters, hematocrit level in P. olivaceus exposed to nitrate was significantly increased only at a concentration of $1,000mg\;L^{-1}$ in biofloc and at concentrations higher than $250mg\;L^{-1}$ in seawater, but no significant changes in hemoglobin were found in biofloc and seawater. In plasma parameters, aspartate aminotransferase (AST) and alanine aminotransminase (ALT) were significantly increased by nitrate exposure in biofloc and seawater, but no significant changes in alkaline phosphatase (ALP) were found in biofloc and seawater. Results of this study indicate that nitrate exposure to P. olivaceus have a lethal toxic effect and alter hematological and plasma constituents of flatfish P. olivaceus. Given relatively lower toxicity of nitrate in biofloc than in seawater, the use of biofloc in aquaculture may reduce potential toxic effect caused by nitrate in feces and feed residue.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.93-100
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• 2020

Hybrid grouper (Epinephelus fuscoguttatus ♀×E. lanceolatus ♂) (mean weight 27.3±3.8 g, mean length 11.6±0.7 cm) were exposed to waterborne nitrite at 0, 100, 200, 400, 800, and 1600mg L^-1 for 96 hours. The hematocrit and hemoglobin values were significantly decreased by exposure to 100 mg L^-1 and 400 mg L^-1, respectively. In plasma components, no significant change was observed in magnesium. Glucose was significantly increased by 200 and 400 mg L^-1 nitrite but reduced by 800 mg L^-1. Cholesterol was significantly decreased by 400 mg L^-1 nitrite, but there was no significant change in total protein. GPT(glutamic pyruvate transaminase) was significantly increased by exposure to 200 and 400mg L^-1. ALP(Alkaline phosphatase) was significantly increased by 800 mg L^-1. The results of this study indicate that acute exposure to nitrite changes physiological parameters, such as hematological properties and plasma components.

• Journal of fish pathology
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• v.17 no.1
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• pp.67-74
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• 2004

This study investigates the influence of waterborne ammonia and nitrite on the zoea and megalopa stage larvae of tiger crab, Orithyia sinica under laboratory condition, focusing on the effects on survival and growth as deleterious responses of toxicant. Survival rate of zoea stage larvae exposed to control levels, and to 5, 10, 20 and 50 mg/L total ammonia-N, using a continuous flow system for 20 days was 80, 77, 45, 40 and 37%, respectively. Growth rate of zoea stage larvae exposed to 20 and 50 mg/L total ammonia was significantly lower than in controls after 20 days (P< 0.05). Survival rate and growth rate of megalopa stage larvae exposed to ammonia also decreased at greater than 10 and 50 mg/L, respectively. In the nitrite exposure experiment with zoea and megalopa stage larvae of tiger crab, survival rate was decreased in a concentration and exposure period-dependent way. The growth rate of zoea and megalopa stage larvae of tiger crab exposed to nitrite decreased at greater than 150 mg/L nitrite concentration.

• Fire Science and Engineering
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• v.32 no.3
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• pp.88-94
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• 2018

Fingerprints deposited on paper found at a fire scene are important evidence for determining a suspect's identity. On the other hand, because the temperature at the fire scene is very high, there are many difficulties in developing fingerprints. This study compared the effectiveness of ninhydrin, DFO, and silver nitrate to develop fingerprints deposited on paper exposed to high temperatures. Using a dry heat press, heat was applied to the paper at $200^{\circ}C$ for various times. Silver nitrate was found to be superior to the others under all conditions. Ninhydrin developed fingerprints weakly compared to DFO and silver nitrate. In addition, the sensitivity of DFO decreased with increasing exposure time. Therefore, it is recommended silver nitrate be used to develop fingerprints deposited on paper found at a fire scene.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.153-157
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• 2004

다양한 혐기성 조건에서 다환방향족탄화수소(PAHs)로 오염된 토양의 미생물 분해 연구를 수행하였다. 대표적인 다환방향족탄화수소인 phenanthrene과 fluorene을 토양과 물에 오염시켜서 약 100일 동안 저감정도를 관찰하였고, 실제 다환방향족탄화수소로 오염된 현장 토양을 이용 혐기성하에서 다환방향족탄화수소의 생분해 가능성을 확인하였다. 미생물 접종원은 혐기성 조건에서 다환방향족탄화수소에 노출시킨 슬러리가 사용되었다. 황산염 환원조건, 질산염 환원조건, 메탄생성조건 등의 다양한 혐기성 조건에서 실험을 수행한 결과, 메탄생성조건 > 질산염 환원조건 > 황산염 환원조건의 순서로 분해가 잘 일어났다. 또한 현장오염토양의 경우 34일간 처리 후 메탄생성조건에서 최대 72%의 분해율을 보였다.

• Explosives and Blasting
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• v.33 no.2
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• pp.1-14
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• 2015

This study was performed to investigate the manufacturing process of the Yeomcho(potassium nitrate), a necessary raw material for making gunpowder using soils and ashes by our ancestor. 10 types of soils including underfloor soil and 6 kinds of ashes including mugwort ash were collected, referencing the historical record. The ionic components extracted from the soils and ashes were analyzed by ICP(inductively coupled plasma atomic emission spectrometer) and IC(ion chromatograph). Nitrate ions and potassium ions were dominantly contained in soils and ashes, respectively. In particular, nitrate ions were found in the highest lebels in underfloor soil which often has much exposure to human living environments and accumulated fine organic matter. Potassium ions contained in ash was affected significantly by the type of plant and the growth environments and the measured levels were the highest in mugwort ashes. Yeomcho of 68% purity was obtained from the soil and ash mixture of 1:1 and thid purity was improved by about 14% by fractional crystallization method.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.119-128
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• 2017

BACKGROUND: Miscellaneous cereal have been largely consumed in Korea as due to their physiological functions beneficial to human health. The cereals are currently a social concern because they have been found to contain heavy metals. Thus, monitoring heavy metals in the cereals is an important requirement for food safety analysis. In this study, we determined arsenic concentration in the cereals randomly harvested from different markets. METHODS AND RESULTS: Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection and recover test to reach $0.13-1.24{\mu}g/kg$ and 94.3-102.1%, respectively. The concentrations of inorganic arsenic equivalent to daily exposure were levels of $19.91{\mu}g/day$ in mixed grain, $1.07{\mu}g/day$ in glutinous rice, $0.77{\mu}g/day$ in black brown rice, $0.13{\mu}g/day$ in barley and $0.11{\mu}g/day$ in soybeans. CONCLUSION: The levels of arsenic in miscellaneous cereals were found lower than the recommended The Joint FAO/WHO Expert Committee on Food Additives (JECFA) levels, suggesting that the cereals marketed in Korea are not potential concern in risk assessment.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.242-246
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• 2004

Nano-sized a-alumina with a narrow distribution was prepared by using Flame Spray Pyrolysis (FSP). The microemulsion of water in oil (W/O) was prepared to make ultrafine droplets for FSP process. Kerosene (fuel) as a continuos phase and Al(NO$_3$)$_3$$.$9$H_2O$ (oxidizer) aqueous solution as a dispersed phase were prepared for microemulsification. The microemulsion with dispersion stability was obtained by adjusting the composition of 80 vol% kerosene, 10 vol% aqueous solution, and 10 vol% emulsifying agent. Microemulsion was sprayed onto the flame by using two-fluid nozzle spray gun under the condition of 0.03 ㎫ air pressure. The synthesized products were $\alpha$-alumina phase with the size of 20 to 30 nm.

• Journal of Life Science
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• v.13 no.1
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• pp.110-117
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• 2003

A thermotolerant yeast strain, Saccharomyces cerevisiae KNU5377 (abbreviated as KNU5377, was exposed to inorganic acids including sulfuric, nitric and hydrochloric acid. As a stressor, each inorganic acid is very easily dissociated in water, resulting in lowering environmental pH. When compared with a reference S. cerevisiae ATCC24858, KNU5377 could overcome such a severe condition containing a final 0.4% concentration of sulfuric acid or nitric acid to grow at the overnight culture, but this reference could not. Additionally, this strain showed a surprisingly strong tolerance by surviving despite of exposure to the regime of 0.35% of hydrochloric acid for over 90 min and also to 0.6% of sulfuric acid for 30 min. On the contrary, both strains could not survive against a final 0.45% concentration of nitric acid. This strain KNU5377 could produce ethanol of 3% in 2 days by using the fermentation medium containing a final 0.3% concentration of sulfuric arid. Moreover, change into a final 0.2% concentration of sulfuric acid caused this strain to enhance fermentation productivity up to about 4.5% even at $40^{\circ}C$. In exposure to a final 0.2% of sulfuric acid for 60 min, trehalose was most accumulated within 30 min in KNU5377, and this suggested a cellular defense system led by this disaccharide was profitable for this strain to lead to no morphological changes.