• 한국환경성돌연변이발암원학회지
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• 제15권2호
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• pp.122-130
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• 1995

In order to evaluate the cytotoxicity of lead in cultures of Balb/c mouse 3T3 cell line, various cytotoxic assays were carried out after expose cells to various concentrations of lead nitrate. Cytotoxic assays using this study were included NR assay, MTT assay, measurement of LDH and protein, synthetic rate of DNA and UDS. Intrace!!ular Ca$^{2+}$ level was also measured. Light and electron microscopic studies were done for morphological changes of lead-treated cell cultures. The results were as follows; 1. The absorbances of NR and MTT were decreased dose-dependently, and NR, and MTT, values of lead nitrate were 3.4 mM and 1.5 mM, respectively. 2. Amount of LDH released into the medium was increased in dose-dependently and LDH activity at 5 mM concentration of lead nitrate was increased to 335 % of control. 3. Amount of total protein was decreased dose-dependently, and which was half of control at 2 mM concentration of lead nitrate. 4. The synthetic rate of DNA was decreased dose-dependently, and also which was remarkably decreased at 3 mM and 5 mM concentrations of lead nitrate. 5. The synthetic rate of UDS was increased at 1 mM concentration of lead nitrate, but which was remarkably decreased at 3 mM and 5 mM concentrations of lead nitrate. 6. Intrace!lular Ca$^{2+}$ level was remarkably increased at 1 mM concentration of lead nitrate, compared with control. 7. In light microscopy, number of cells and processes were decreased according to the increase of dosage of lead nitrate. Electron microscopic findings showed that many vacuoles and cisternal dilatation of rough endoplasmic reticulum were seen in the cytoplasm at 1 mM concentration of lead nittale. From the above results, high dosage treatment of lead nitrate (>3 mM) damaged genetic malerials and it also showed cytotoxicity in mouse 3T3 cell line cultures by injury of cell organelles and Ca$^{2+}$ channel.

• 자원리싸이클링
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• 제7권2호
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• pp.31-38
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• 1998

2차납 제련공정에서 발생한 주성분이 황산납인 연진으로부터 고부가가치제품인 정제 질산납을 생산하는 습식공정을 개발하였다. 본 공정은 탄산염에 의한 탄산화 공정과 저농도 질산용액을 이용한 침출공정 및 정제 공정으로 구성되어 있으며 본 공정을 통하여 99%이상의 순도를 가진 질산납을 제조할 수 있었다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 춘계학술대회
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• pp.115.3-115
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• 1979

중금속을 함유한 13종의 질산염을 명 농도별로 첨가하여 주정효모 Saccharomyces cerevisine의 주정생산과 발효작용에 미치는 영향을 조사하였다. 1. 일반적으로 중금속을 함유한 질산염은 그 첨가량이 0.0001mo1. 보다 고농도일수록 Saccharo-myces cerevisiae의 발효작용을 점차 억제하였다. 2. Nickel nitrate, chromium nitrate들의 0.0001 moi.의 첨가는 Saccharomyces cerevisiae의 alcohol 발효작용을 약간촉진시켰다. 3. Cadmium nitrate 0.001mo1. 이상, cupric nit-rate, nickel nitrate, cobalt nitrate 0.01mo1. 이상, 그리고 silver nitrate, mercurous nitrate, manganese nitrate, zinc nitrate, lead nitrate, chromiun nitrate, ferric nitrate, bismuth nitrate 0.1mol. 의 농도에서 Saccharomyces cerevisiae 의 발효작용은 완전히 조지되었다.

• Bulletin of the Korean Chemical Society
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• 제15권5호
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• pp.390-393
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• 1994

Details on the electrochemical formation of lead dioxide from aqueous plumbous ion are studied by measuring current-time behavior with potential step method at a rotating platinum electrode. A cubic law without induction period can be applied to the crystallization of lead dioxide in both acetate and nitrate media. In the course of the mechanistic study, the presence of a soluble intermediate during the nucleation step is clearly observed with a rotating ring-disk electrode. Decrease in the anodic ring current due to the reduction of soluble species formed during the anodic crystallization of lead dioxide at disk is detected.

• 한국응용과학기술학회지
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• 제10권1호
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• pp.23-29
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• 1993

Transesterification reaction between dimethyl phthalate and ethylene glycol was kinetically investigated in the presense of various metal nitrate catalysts at $170^{\circ}C$. The reaction rates measured by the amount of distilled methanol from the reaction vessel. The transesterification reaction was carried out under the first order conditions respect to the concentration of dimethyl phthalate and catalyst, respectively. The over all order was 2nd. By Arrhenius plot, the activation energy was calculated as 17.4kcal/mole and 17.2kcal/mole on the transesterification reaction with zinc nitrate and lead nitrate, respectively. Apparent rate constant, k' was appeared linear about concentration of catalyst.

• Ocean and Polar Research
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• 제27권3호
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• pp.341-349
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• 2005

Temporal variation of the natural planktonic community in the Southern Sea of Korea was investigated by using low floating enclosed bags (3.2m deep and 2,500 liter) in order to understand the effect of enriched nitrate on the planktonic community in the spring (March-April) of 2002. Prior to beginning the incubation, the bags were placed in two different concentrations of nitrate, which consisted of control (ambient water) and experimental mesocosms (final concentration of $12{\mu}M$). The nitrate concentration in the experimental mesocosms remained significantly higher than those in control mesocosms throughout the study period (ANOYA, p<0.001). Following the addition of nitrate, abundance and chi-a concentration of phytoplankton peaked on Day 1, when diatoms established the peak in the experimental mesocosms. Diatoms consisted mainly of Thalasxiosira decipiens, Pseudo-nitzschia pungem, Leptocylindrus danicu, Thalassionema nitzschioides, Chaetoceros pseudocrinitus and Actinoptychus senariu. However, the peak did not lead to the difference in abundance and composition of phytoplankton between control and experimental mesocosms during the study period. The dinoflagellates began to increase soon after the diatoms decreased in all mesocosms. Copepods, as a dominant group in the rnosozooplankton community, showed no immediate peak in relation to the nitrate addition, but only their own developmental process from the eggs to adult stage during the study period. The bottom-up control from enriched nitrate via phytoplankton to adult copepods was not distinguished in terms of the abundance of the planktonic community. This might stem from the relatively low nitrate availability of phytoplankton at no N-limited seawater and the weak coupling between rapidly sunken diatoms and copepods through the water column.

• 한국환경복원기술학회지
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• 제5권6호
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• pp.24-29
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• 2002

Nitrate removal rate in three cattail wetland cells was investigated. They were a part of a pond-wetland system for stream water treatment demonstration. The system was composed of two ponds and six wetland cells. The acreage of each cell was approximately $150m^2$. The earth works for the system were finished from April 2000 to May 2000 and cattails were planted in the three cells in June 2000. Waters of Sinyang Stream flowing into Kohung Estuarine Lake were pumped into a primary pond, whose effluent was discharged into a secondary pond. The reservoir was formed by a tidal marsh reclamation project and located in southern coastal area of Korean Peninsula. Effluents from the secondary pond were funneled into the three cells. Volumes and water quality of inflow and outflow were analyzed from July 2000 through January 2001. Inflow and outflow averaged $20.2m^3/day$ and $19.8m^3/day$, respectively. Hydraulic retention time was about 1.6 days. Average influent and effluent nitrate concentration was $1.98mg/{\ell}$, $1.38mg/{\ell}$, respectively. Nitrate removal rate averaged $82.6mg\;m^{-2}\;day^{-1}$. Seasonal changes of nitrate retention rates were closely related to those of wetland cell temperatures. The average nitrate removal rate in the cells was a little lower, compared with that of $125.0mg\;m^{-2}\;day^{-1}$ for the wetlands operating in North America. This could be attributed to the initial stage of the cells and inclusion of three cold months into the seven-month study period. Root rhizosphere in wetland soils and litter-soil layers on cell bottoms could not developed. Increase of standing density of cattails within a few years will establish both root zones suitable for the nitrification of ammonia to nitrates and substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increase of the nitrate retention rate.

• Journal of Nutrition and Health
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• 제17권3호
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• pp.193-198
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• 1984

Rice, the staple food in Korea, is deficient to some extent in protein, lipid and vitamins. This study was carried out in order to investigate the effects of dietary supplementation to the rice diet of cellulose, ginseng, and ${\alpha}$-tocopherol on lead toxicity in rats. Using male rats fed the rice diet with the distilled drinking water containing 750mg of lead as nitrate per liter, for 11 weeks, organ weights, hemoglobin levels, serum glutamic pyruvic transaminase activity and accumulation of lead in liver, blood and kidney were observed. Supplementation of cellulose, ginseng and ${\alpha}$-tocopherol to the lead groups showed the protective effect significantly in the weight of liver but no influence in hemoglobin levels. Ginseng especially decreased the serum glutamic pyruvic transaminase activity to normal level. The three supplemented diets reduced the lead accumulation in kidney and blood, but not in liver.

• 한국토양환경학회지
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• 제5권2호
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• pp.99-105
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• 2000

본 연구는 Pb으로 오염된 토양을 Biofilter에 의한 적용가능성을 판단하고 충전물질, bed수 그리고 미생물 접종에 따른 Pb의 이동억제효과의 변화를 Pilot plants의 실험을 하였으며 토양의 분해정도를 CODcr/TOC ratio로써 안정화 지표에 대한 변화를 검토하였다. 생물여과는 오염된 물질을 생물여과상를 통과시켜 충전물질표면에 부착되어있는 생물막의 각종미생물들에 의한 경계면을 통하여 물질의 상호교환 및 전환이 생기며 생물막내에 흡수된 물질을 생물학적으로 처리하는 방법의 일종이다. 본 연구는 오염된 토양에 lead nitrate를 첨가시켜 납을 1,000㎎/kg dry soil로 인공적으로 조제한후 충전물질로는 퇴비, 바이오세라믹 그리고 퇴비와 바이오세라믹을 중량비로 7:3으로 하였고, 1단, 2단, 3단으로 하고 이에따라 생물흡착제로 'Aspergillus niger'를 이용하며 납의 이동억제효과의 변화를 검토하였다.

• Journal of Electrochemical Science and Technology
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• 제8권3호
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• pp.197-205
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• 2017

Lead dioxide thin films were electrodeposited on nickel substrate from acidic lead nitrate solution. Current efficiency and thickness measurements, cyclic voltammetry, AFM, SEM, and X-ray diffraction experiments were conducted on $PbO_2$ surface to elucidate the effect of lead nitrate concentration, current density, temperature on the morphology, chemical behavior, and crystal structure. Experimental results showed that deposition efficiency was affected by the current density and solution concentration. The film thickness was independent of current density when deposition from high $Pb(NO_3)_2$ concentration, while it decreased for low concentration and high current density deposition. On the other hand, deposition temperature had negative effect on current efficiency more for lower current density deposition. Cyclic voltammetric study revealed that comparatively more ${\beta}-PbO_2$ produced compact deposits when deposition was carried out from high $Pb(NO_3)_2$ concentration. Such compact films gave lower charge discharge current density during cycling. SEM and AFM studies showed that deposition of regular-size sharp-edge grains occurred for all deposition conditions. The grain size for high temperature and low concentration $Pb(NO_3)_2$ deposition was bigger than from low temperature and high concentration deposition conditions. While cycling converted all grains into loosely adhered flappy deposit with numerous pores. X-ray diffraction measurement indicates that high concentration, high temperature, and high current density favored ${\beta}-PbO_2$ deposition while ${\alpha}-PbO_2$ converted to ${\beta}-PbO_2$ together with some unconverted $PbSO_4$ during cycling in $H_2SO_4$.