• 한국지하수토양환경학회지:지하수토양환경
• /
• 제16권5호
• /
• pp.1-8
• /
• 2011

This study was performed to evaluate the remediation efficiency by Helianthus annuus, Brassica juncea and Brassica campestris on the soil contaminated with nickel, zinc and lead, respectively. The growth rates fell down under 60% in the condition of over 700 mg/kg of zinc for Brassica campestris, 300 mg/kg of lead for Helianthus annuus, and 150 mg/kg of nickel for Brassica juncea on the basis of heavy metal concentration in the soil, because of its toxicity. Also, the hyperaccumulators showed the maximum heavy metal contents in their biomass after 90 days of cultivation. The accumulated heavy metal content per kilogram of hyperaccumulator was 0.65 mg of nickel in Brassica juncea, 0.14 mg of zinc in Brassica campestris, and 0.06 mg of lead in Helianthus annuus, respectively. Additionally, 73.2% of nickel accumulated in Brassica juncea and 95.1% of zinc accumulated in Brassica campestris were concentrated in the upper site of crop like stem and leaves. However, in the case of Helianthus annuus, 83.7% of lead was accumulated in the root.

• 환경위생공학
• /
• 제4권1호
• /
• pp.53-60
• /
• 1989

This study was performed to investigate the contents of heavy metals in Anguilla japonica habiting in Korea. The samples were collected along by Nak Tongriver, Young San river and culture farms. Lead, Cadmium, Copper, Zinc, Manganese, Chromium were tested by the Atomic Absoption Spectrop-hotometer after wet digestion, Mercury was tested by using mercury analyzer. The results were as follows: 1. Aresenic, Copper contents in the four parts were the higest values in liver 2. In total mercury contents of the each parts, the higest value was detected in muscle. 3. In all metals, Zinc and Manganese were detected with high contents, Mecury and Cadmium were detected with low contents. Lead, Cadmium, Zinc, chromiumi, Manganese were detected with high in bone. 4, The difference was not significant between natural and feeding Anguilla Japonica, but significant correlation with parts.

• 한국식품위생안전성학회지
• /
• 제1권1호
• /
• pp.51-56
• /
• 1986

In the particular area the heavy metal concentrations in the soil were determined and compared to the contents in vegetables which were grown on the soil. Simultaneously the degree of contamination was examined. Samples were collected from Chinese cabbage, radish and Altari-mu, together with the soil on which the three kinds of vegetables have grown. The sites of samples collection were Jinguan-sa(non-polluted area) and Sangaedong(polluted area). The contents of cadimium, copper, lead and zinc were determined by means of atomic absorption spectro-photometer. The results obtained were as follows; 1. In soils, the average contents of heavy metal in Jinguan-sa area (Cd; 0.15ppm, Cu; 0.15ppm, Zn; 11.5ppm) were lower than those in sangye-dong(Cd; 0.26ppm, Cu; 13.0ppm, Zn; 17.1ppm). 2. In vegetables, the average have metal contents in Jinguan-sa were cadmium; 0.11ppm, copper; 5.29ppm, zinc; 18.75ppm and the average contents in Sangye-dong were cadmium; 0.16ppm, copper; 6.64ppm, lead; 0.14ppm, zinc; 15.01ppm. 3. The contents of lead showed zero ppm in Jinguan-sa area(soil and vegetables). In vegetables difference in concentration of heavy metals was not observed between reclaimed area and non reclaimed area. Statistical analysis showed that no correlation in the heavy metal concentrations between those in soils and in vegetables.

• 산업보건소식
• /
• 제48호
• /
• pp.9-18
• /
• 1987

The results of this study which had been investigated to analyse heavy metal levels and to compare lead, cadmium, copper and zinc concentration in urine of children who lived around the industrial area and the agricultural area. Samples were collected and analyzed from September to December 1986 from 7-9 years old children living in Seoul (4 7 cases), lri ( 64 cases) industrial area and Chinan (56 cases) agricultural area. The summarized results were as follows: 1) The concentrations of lead were Seoul 28.7 $\pm$17.7 ug/l, lri 25.3 $\pm$7.5 ug/l and Chinan 19.3 $\pm$5.2 ug/l 2) The concentrations of cadmium were Seoul 1.5 $\pm$0.8 ug/l, Iri 1.4 $\pm$0.5 ug/l and chinan 0.9 $\pm$0.3 ug/l 3) The concentrations of copper were Seoul 12.8 $\pm$7.0 ug/l, Iri 10.5 $\pm$8.4 ug/l and Chinan 10.0 $\pm$4.5 ug/l 4) The concentrations of zinc were Seoul 383 $\pm$279 ug/l, Iri 329 $\pm$133 ug/l and Chinan 267 $\pm$181 ug/l 5) In lead, cadmium and zinc concentration of children, there were statistical difference between the industrial area and the agricultural area 6) There were no indicated significantly levels by the Sex

• Structural Engineering and Mechanics
• /
• 제64권2호
• /
• pp.195-204
• /
• 2017

Analytical and experimental studies of the innovative pipe in pipe damper have been recently investigated by the authors. In this paper, by adding lead or zinc infill or slit diaphragm inside the inner pipe, it is tried to increase the equivalent viscous damping ratio improving the cyclic performance of the recently proposed multi-level control system. The damper consists of three main parts including the outer pipe, inner pipe and added complementary damping part. At first plastic deformations of the external pipe, then the internal pipe and particularly the added core and friction between them make the excellent multi-level damper act as an improved energy dissipation system. Several kinds of added lead or zinc infill and also different shapes of slit diaphragms are modeled inside the inner pipe and their effectiveness on hysteresis curves are investigated with nonlinear static analyses using finite element method by ABAQUS software. Results show that adding lead infill has no major effect on the damper stiffness while zinc infill and slit diaphragm increase damper stiffness sharply up to more than 10 times depending on the plate thickness and pipe diameter. Besides, metal infill increases the viscous damping ratio of dual damper ranging 6-9%. In addition, obtained hysteresis curves show that the multi-level control system as expected can reliably dissipate energy in different imposed energy levels.

• 한국세라믹학회지
• /
• 제21권4호
• /
• pp.349-354
• /
• 1984

The purpose of present study is to find the structure crystallization mechanism and physical properties in $TiO_2$ containing lead zinc borosilicate glass system. The experiments such as differential thermal analysis infrared spectral analysis. X-ray diffraction analysis and thermal expansion measurements have been done. Differential thermal analysis of coarse and fine glass powder showed bulk nucleating mechanism for high $TiO_2$ containing glasses and surface nucleation mechanism for low $TiO_2$ containing glasses. The prepared glasses crystallized to crystalline mixture of PbO.2ZnO. $B_2O_3$ .4PbO.2ZnO.$5B_2O_3$and 2PbO.ZnO.$B_2O_3$ when heat-treated in the range of 480 and 51$0^{\circ}C$ and crystallized to PbTiO3 when heat-treated at $600^{\circ}C$. Obtained crystalline phase of $PbTiO_3$ in glass matrix strongly affects to thermal expansion coefficient and the value of crystallized glass varied 68.0 to $107.1{\times}10-7$/$^{\circ}C$ depending on the amount of $TiO_2$added. Infrared spectral analysis showed that [$BO_3$] triangle and [$BO_3$] tetrahedral units were coexisted in the glass with high content of PbO.

• 자원리싸이클링
• /
• 제30권5호
• /
• pp.3-9
• /
• 2021

우리나라에서 연, 아연, 동, 주석, 니켈, 알루미늄 등의 베이스메탈의 수급구조는 양극화된 특성을 지니고 있다. 연, 아연, 동 등은 국내에 세계적 규모의 생산기업이 있는 반면, 주석, 니켈, 알루미늄 등은 국내 생산기업이 전무하거나, 생산량이 미비하여 내수량의 대부분을 수입에 의존하고 있다. 따라서 베이스메탈의 수입중단 또는 국내생산기업의 생산 중단 등의 공급중단에 따른 리스크에 대한 대비가 필요하다. 본 연구에서는 베이스메탈 6종(구리, 연, 아연, 알루미늄, 니켈, 주석)을 대상으로 수입중단 리스크 발생 시 대응이 필요한 물량과 시장이 대응할 수 있는 물량, 정부가 대응해야 하는 물량(전략비축)을 정량화하였다.

• 대한조선학회논문집
• /
• 제41권1호
• /
• pp.88-93
• /
• 2004

Electrochemical impedance spectroscopy was used to evaluate the anticorrosive properties of resin(alkyd, epoxy, urethane) and pigment(hydroxy apatite(HAp), zinc potassium chromate(ZPC). red lead(RL)). The corrosion behavior of coatings applied on steel has been investigated during exposure to 0.5M-NaCl The anticorrosive performances of resins were found to depend on their chemical nature and decreased in the order of urethane > epoxy > alkyd resin coating. Hydroxy apatite and zinc potassium chromate pigment which have property to passivate the substrate showed relatively high anticorrosive performance.

• 한국환경보건학회지
• /
• 제21권3호
• /
• pp.77-86
• /
• 1995

Lead(II) removal efficiency by natural kaolinite was investigated through laboratory experiments. This study was conducted in two phases-sorption and desorption. In the adsorption study, the influence of sorption kinetics and sorption isotherm and various parameters such as pH, temperature, coexisting other heavy metal ions on the lead adsorption was investigated. And desorption study was carried out in order to find the re-usability of kaolinite as an adsorbent. The results of the study are as follows. 1. Sorption kinetics was investigated under the condition of 2.5 mg/l adsorbent concentration, pH 6.5$\pm$0.05, temperature $30\pm 0.5\circ$C, initial lead(II) concentration 25 mg/l. Adsorption rate was initially rapid and the extent of adsorption arrived at adsorption equilibrium with 73% adsorption efficiency in an hour. 2. The sorption isotherm experiment was made with different initial lead(II) concentration. A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the sorption intensity (1/n) was 0.47 and the measure of sorption (k) was 2.44. So, it was concluded that sorption of lead(II) by kaolinite is effective. 3. The effect of pH on lead(II) sorption by kaolinite shows that at a pH of 3, only 6% of the total lead(II) was adsorbed and at a pH 9, 97% of the lead(II) was removed. And the effect of temperature on lead(II) sorption by kaolinite shows that as the temperature increased, the amount of lead(II) sorption per unit weight of kaolinite increased. But the effect was minor (p<0.05). 4. Sorption isotherm of lead coexisting cadmium (II) or zinc (II) was lower than that of lead itself. It was caused by the result of competitive sorption to adsorption site. And there was no difference between the sorption isotherm of cadmium and zinc. 5. In desorption studies, only 5.12% desorption took place in distilled water, while 52.08% in 0.1 N hydrochloric acid. Consequently used kaolinite could be regenerated by hydrochoric acid.

• E2M - 전기 전자와 첨단 소재
• /
• 제10권5호
• /
• pp.473-480
• /
• 1997

Surface passivation using glass powders results in good reliability for high voltage silicon power devices. In this paper Zinc borosilicate glass and Lead borosilicate glass were prepared for the purpose of passivating, and a deposition technique of glass films on the silicon surface by electrophoresis in which acetone is used as a suspension medium has been investigated. Their physical properties were compared using DTA, SEM, XRD, as a function of firing temperature, I can get the fine films of 22${\mu}{\textrm}{m}$ thickness with Lead borosilicate glass under 300 volts applied, 3 minutes and $700^{\circ}C$ firing temperature. Also I can get the fine films of 17${\mu}{\textrm}{m}$ thickness with Zinc borosilicate glass under same conditions. As a result of investigation of glass films from which glass layer was removed by placing it in HCl, it has been found that pre-firing and annealing play an important role to achieve uniform and fine glass deposition films. And also it was found that relative dielectric constant is independence of frequency.