• Journal of Nutrition and Health
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• 제36권2호
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• pp.117-124
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• 2003

한국전통차로 알려진 녹차, 감잎, 홍화 및 두충 열수추출물이 납투여된 흰쥐의 유해 활성산소 대사에 미치는 영향을 구명하기 위하여 체중 kg당 25 mg의 납을 매주 1회 경구 투여 하였다. 녹차, 감잎, 홍화 및 두충 열수추출물은 매일 일정시간에 체중 kg당 1.26 g 수준이 되도록 4주간 경구 투여 하여 사육한 결과 간조직 중 과산화지질 함량은 납 단독투여군이 정상군에 비하여 유의적으로 증가되었으며 한국전통차 급여시 과산화지질 생성을 현저하게 억제하는 것으로 나타났다. 간조직 중의 CYP 함량과 AD 활성은 납 투여시 유의적으로 감소되었으나 각각의 열수추출물 급여시 납투여로 억제된 활성이 회복됨으로써 한국전통차 급여가 CYP 함량과 산화적 디메틸화율을 증가시키는 것으로 관찰되었다. 또한 납투여로 증가된 간조직의 XO와 SOD의 활성은 녹차, 감잎, 홍화 및 두충 열수추출물 급여시 활성이 유의적으로 억제되었다. MAO 활성은 납 투여시 정상군에 비하여 유의적이지는 않으나 증가되었으며 녹차와 감잎 열수추출물 급여로 활성 증가가 현저하게 억제되었다. 간조직 중 CAT 활성은 납투여시 약 3.3배 증가되었는데 감잎군 37%, 녹차군 34%, 두충군 30%, 홍화군 28%, 순으로 억제되는 것을 관찰할 수 있었다. 또한 GSH-Px와 GST 활성 및 글루타티온 함량은 정상군에 비하여 납 단독투여시 유의적인 감소를 보였으나 한국전통차 급여로 회복되었다. GR 활성은 실험군간에 변화가 관찰되지 않았으나 G6PD 활성은 납투여로 증가된 활성이 실험식이 급여시 유의적으로 감소되었다.

• 자원환경지질
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• 제37권3호
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• pp.311-324
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• 2004

전라남도 보성강에 축조된 주암댐의 집수유역 내 하상퇴적물을 대상으로 중금속의 오염현황과 거동 특성을 알아보았다. 주암댐의 집수유역에는 많은 폐금속 및 탄광이 위치하고 있어 주암댐 호저퇴적물에 잠재적인 오염원으로 작용할 수 있다. 집수유역 내 하상퇴적물의 중금속 함량(Cr, Cu, Ni, Pb, Zn)은 매우 낮기 때문에 주암댐의 호저퇴적물에 영향을 줄 것으로 판단되지 않는다. 하지만 폐금속광산지역 내 하상퇴적물의 Pb 함량은 하류로 갈수록 증가하는 경향을 보여, Pb의 오염 확산이 우려된다. 폐금속광산의 환경을 고려한 강산성 조건의 용출실험결과, 하상퇴적물의 용출비로부터 결정된 중금속의 상대적 이동도는 Pb＞Zn=Cu＞Ni＞Cr으로서, Pb이 주암댐 호저퇴적물에 영향을 미치는 원소가 될 수 있음을 지시해준다. 한편 댐으로 유입한 퇴적물이 호저에 놓이게 되면(즉, 환원환경), Pb의 이동도가 비교적 높게 나타나 물-퇴적물 경계에서 Pb의 수중으로 재용출될 수 있다.

• 한국응용과학기술학회지
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• 제30권3호
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• pp.551-559
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• 2013

To investigate the adhesion effect of sodium bisulfite content in making blocked isocyanate, wood adhesive PB-1, PB-2, PB-3 and PB-4 containing sodium bisulfite content of 15%, 22.5%, 30% and 37.5% were synthesized respectively. As a result, when the amount of sodium bisulfite increased in adhesives, the tensile strength was found to be proportionally increased. The final adhesive mixtures were manufactured using a two-components system which are prepared by mixing two separate protein and BI solutions due to the precipitate in the adhesives. As PVA was added to adhesives to increase tenacity, the plywood dehiscence phenomenon after cold pressing process was declined. By addition of PVA, the tensile strength was improved up to $6.5{\sim}7kgf/cm^2$ with BI/protein ratio from 1:6 up to 1:8. Phase separation between milk fat and aqueous layer was disappeared after addition of emulsifier, Tween 20. Additon of Tween 20 showed tensile strength up to $5{\sim}6.5 kgf/cm^2$ at NCO/protein ratio of 1:12 ~ 1:14 without phase separation.

• 한국환경보건학회지
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• 제14권1호
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• pp.73-86
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• 1988

In order to determine the content levels of trace metals in common salts, 64 bay salt samples were collected from three producing districts and 33 bay salt samples, 32 remade salt samples and 5 fine salt samples were collected from 7 major cities in Korea, from August to September 1987. These were analysed for content levels of Pb, Cd, Cu, Zn and Mn using Atomic Absorption Spectrophotometer. The results were as follows: 1. Lead contents in three type salts were N.D. - 1081.9 $\mu$g/kg and fourteen percent of the 114 samples exceeded the World Health Organization(WHO) criteria of 100$\mu$g/kg. Cadmium contents of samples were N.D.- 382C.5 $\mu$g/kg and five percent of the 114 samples were over the Spanish criteria of 500 $\mu$g/kg. Copper contents of samples were 8,9-214.9 $\mu$g/kg and there was not a sample over the World Health Organization(WHO) criteria of 500 $\mu$g/kg. Zinc contents ranged N.D. - 342.9 $\mu$g/kg and Manganese contents ranged N.D.- 8.31 mg/kg. 2. The comparison of heavy metal contents among the bay salts from three producing districts was significantly different in Pb, Cd and Cu contents. 3. The comparison of heavy metal contents between the bay salts and remade salts was not significantly different in Pb, Cd and Cu contents. 4. The contents of Pb, Cd, Zn and Mn in fine salts were much lower than those of bay salts and remade salts.

• The Plant Pathology Journal
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• 제28권4호
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• pp.446-452
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• 2012

The effect of heavy metals on seedling growth and pigment levels was studied in Arabidopsis using essential (Cu, Mn, and Zn) and non-essential metals (Pb and Hg). Generally increasing the concentrations of the metals resulted in a gradual decrease in root and shoot lengths, a decrease in chlorophylls, an increase in anthocyanins and a fluctuation in carotenoid content depending on the metal types. The toxicity of the metals decreased in the following order: Cu > Hg > Pb > Zn > Mn. Among the five metals, Cu was exceptionally toxic and the most potent inducer of anthocyanins. Pb induced the smallest quantity of anthocyanins but it was the strongest inducer of carotenoids. It suggests that the Cu-stressed Arabidopsis may use anthocyanins as its main antioxidants while the Pb-stressed Arabidopsis use carotenoids as its main protectants. All of the five metals induced an accumulation of anthocyanins. The consistent increase in anthocyanin content in the metal-stressed Arabidpsis indicates that anthocyanins play a major role in the protection against metal stresses.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.18-26
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• 1991

This study was carried out to examine not only the effect and the process of activation of aluminum sulfate for the manufacture of PB and MDF, but also application of the activation treatment to PB and MOF made with MDI adhesive. The results were as follows: 1. For the manufacture of PB, activating effect did not take place Because the low moisture content of 30% in the process of activation treatment made probably insufficient activation. It needs to examine higher moisture content for the uniform and enough activation same as that of MOF. 2. In the case of MOF, Activating effect was excellent, it showed not only better results of MOR 48%, MOE 29%, IB 60% than those of the control but also better dimensional stability. 3. Application of alum activation to the PB and MDF made with MDI adhesive yielded no effects. Maybe it was the reson that the curing mechanism of MDI is different. 4. Modifing the wood surface was the oxidation and wettability was not the variable limiting glueline performance. It is necessary to make a more study about activating reaction.

• 한국세라믹학회지
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• 제32권7호
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• pp.839-845
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• 1995

The structural and dielectric properties of Pb(Mg1/3Nb2/3)O3 ceramics substituted by Nd3+, La3+, K+ and Na+ were studied over 0~50 at.% substituent content. The 1 : 1 ordering behavior of Mg2+ and Nb5+ ions in the B site sublattice was observed in Nd3+-and La3+-modified compounds. The degree of ordering was increased with Nd3+, La3+ content in the compounds. But K+-or Na+-modified compounds did not exhibit the ordering behavior. This was explained by charge and size effect of A and B site cations and oxygen vacancies. As the mole fractions of substituent increased, the maximum values of dielectric constants were rapidly decreased and the phase transitions were broadened. Phase transition temperature was correlated with the covalency of A-O and B-O bonding.

• 보존과학회지
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• 제1권1호
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• pp.27-39
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• 1992

Metallurgical studies of the bronze artifacts excavated from Miruksa Temple were performed by chemical analysis and metallographic observation. Alloy systems of the bronze artifacts were classified into two groups of Cu-Sn and Cu-Sn-Pb, according to the items. The contents of impurities such as Sb, As, Ni and Fe in bronze artifacts are within the limiting range of the mod ern standard bronze castings. Chemical compositions of the kitchen utensils such as bronze vessels and dishes in the Unified Silla dynasty, are in the follow ing range, Cu : 74.8-79.4% and Sn : 18.6-21.1%. Chemical composition of the Buddha-image in Koryo dynasty are 820Cu-7.0Sn-10.3Pb, showing increased Pb content and decreased Sn content. The results of chemical analysis suggest that the chemical compositions were good controlled. Any casting defects such as voids and shrinkage holes are not found microscopically, indicating high casting skill. Zinc atoms are not contained in the all bronze artifacts of Miruksa Temple site. This is the common facts founded in the east asian bronze artifacts of Korea, China and Japan. It is comparable with the European bronze of Cu-Sn-Pb-Zn system, after the Middle Age.

• 한국환경보건학회지
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• 제26권2호
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• pp.116-121
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• 2000

This study was performed to investigate the heavy metal contents and distribution in bioorganisms from the estuary area of Mankyeong-Dongjin river. In paddy plant, the average contents of heavy metals were in order of Zn>Cu>Pb>Cr>Cd in all parts. Those of Cd, Cr, Pb and Cu were all highest in the leaf while lowest in the brown rice. The average content of Zn was almost similar in all parts. In the dried muscular parts of shellfish, the average contents of heavy metals were in the range of 1.06~1.95 mg/kg for Cd, 2.93~4.98 mg/kg for Cr, 0.90~1.17 mg/kg for Pb, 8.41~18.58 mg/kg for Cu and 29.81~67.31 for Zn, respectively, In fish(Acanthogobius hasta), the average contents of heavy metals in the dried body parts were in the range of 0.05~0.43 mg/kg for Cd, 0.65~4.59 mg/kg for Cr, 1.01~4.75 mg/kg for Pb and 1.34~4.19 mg/kg for Cu, with high accumulation in bone and head overally.

• Environmental Analysis Health and Toxicology
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• 제4권1_2호
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• pp.35-45
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• 1989

Studies on the heavy metal content of ginkgo leaves growing in all around Seoul. This study was carried out to investigate the concentration of heavy metals and soluble sulfur in ginkgo leaves. These leaves are found growing in park, residential, commercial and industrial areas all around Seoul. These analyzed the quantity of Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn, Hg and soluble surfur in separate samples of washed and unwashed leaves. The results were as follows: 1. This order of heavey metal concentration was found in Seoul area,: Fe＞Mn＞Zn＞Ni＞Pb＞Cu＞Co＞Cd＞Hg. 2. Pb concentration was higher in the commercial area than in the other areas, and it concentration in washed leaves was higher 96～100% and unwashed leaves 85～170%. 3. In the residential area Ni concentration was significantly higer where about seven times more Ni as found on the top part of the leaves. 4. Water soluble surfur was higest in the inudstrial area, but the percentage on top of the leaves was only 0.04～0.05% simillar with other area. 5. Fe, Zn and Ni were almost positively correlated to each component but negatively correlated between Mn and souble sulfer. All of content except Mn and Ni were significance between each area in washed and unwashed leaves.