This study was concentrated that the contents of heavy metals were estimated from 782 samples of sold fisheries in Seoul(33 species in fishes, 15 in bivalves, 12 in crustaceans and 10 in others) by Atomic Absorption Spectrometer. The contents of As, Cd and Pb [minimum-maximum (mean)] were N.D.-0.162 mg/kg(0.021), 0.001-0.120 mg/kg(0.014) and 0.015-0.499 mg/kg(0.111) in fishes, 0.003-0.311 mg/kg(0.052), N.D.-1.905 mg/kg(0.182) and 0.013-0.462 mg/kg(0.138) in bivalves, N.D.-0.328 mg/kg(0.042), 0.002-1.113 mg/kg(0.079) and 0.006-0.510 mg/kg(0.109) in crustaceans, N.D.-0.181 mg/kg(0.024), 0.001-0.214 mg/kg(0.033) and 0.010-V0.877 mg/kg(0.118) in others respectively, bivalves were the highest than others. The average weekly intakes of three metals from sold fisheries took about 1.4-26.4% of PTWI (provisional tolerable weekly intakes) that FAO/WHO Joint Food Additive and Contaminants Committee had set to evaluate their safety.

This study was conducted to determine the content of heavy metals in canned foods and soft drinks available on the Korean markets. Trace metals (Pb, Cr, Cd, and Sn) were detected in 24 kinds, 120 samples by Atomic Absorption Spectrophotometer. The average concentration of heavy metals in canned foods was in the order of Sn (6.930 ppm)$gt;Cr (0.050 ppm)$gt;Pb (0.030 ppm)$gt;Cd (0.008 ppm), which was the same order in soft drinks as Sn (3.519 ppm)$gt;Cr (0.080 ppm)$gt;Pb (0.024 ppm)$gt;Cd (0.001 ppm). The total contents of heavy metals in canned fruits and fiuit juices were relatively higher than those in cans and drinks made of vegetable and fish. It can be supposed that the high acidity owing to the organic acid of fruit itself promotes to extract metals from can materials, and although fish usually contains more heavy metals than vegetables, canned fish revealed low level because internal organs and most of skin which had more heavy metals than meat were removed throughout canning process. Because processed foods such as canned foods and soft drinks are very popular with the children and adolescence according to the change of life style and eating habit, and the possibility of exposure to heavy metals by the habitual intake of these is increasing simultaneously, it is suggested that more practical study about the process of exposure and the amount in each step is needed for the assessment of safety.

This study was conducted to determine the content of inorganic metals in botanical pills and assess the safety of mineral balance in body. Inorganic metals (Fe, Ca, Zn, Na, Mg, K, Pb, Cd, Cr) were detected in 11 kinds, 51 samples by Atomic Absorption Spectrophotometer. The average concentration of inorganic metals in botanical pills was in the order of K(7933.32 mg/kg)$gt;Na(5848.58 mg/kg)$gt;Ca(2441.60 mg/kg)$gt;Mg(1595.34 mg/kg)$gt;Fe(353.14 mg/kg)$gt;Zn(22.49 mg/kg)$gt;Cr(3.51 mg/kg)$gt;Pb(0.24 mg/kg)$gt;Cd(0.09 mg/kg). In samples, Moms and Laminaria contained a great quantity of K and Na, Acanthopanacis cortex, Eucommia ulmoides, Pinus densiflora, Lycii fiuctus, Allium sativum for. pekinense, and Platycode radix had much more amount of K than that of Na, in the mean time, Artemisia capillaris, Carthamus tinctorius seed, and Rubi fiuctus had various kites of plenty inorganic metals. The contents of Pb in grouped samples by used parts, were in the order of radiac(0.54 mg/kg)$gt;cortex(0.36 mg/kg)$gt;leaves (0.20 mg/kg)$gt;fructus(0.20 mg/kg)$gt;seed(0.07 mg/kg), those of Cd were radix(0.16 mg/kg)$gt;leaves(0.09 mg/kg)$gt;fiuctus (0.07 mg/ kg)$gt;seed(0.06 mg/kg)$gt;cortex(0.03 mg/kg), those of Cr were radix(6.34 mg/kg)$gt;cortex(4.25 mg/kg)$gt;fructus (4.20 mg/ kg)$gt;leaves(2.14 mg/kg)$gt;seed(1.67 mg/kg). In the assessment of risk by the daily intake of botanical pills, the amount of Zn, whose PTWI was 7,000 ㎍/kg b.w/week, covered 0.13-0.83%, that of Pb, whose PTWI was 25 ㎍/kg b.w/week, coverd 0.24-1.94%, and that of Cd, whose PTWI was 7 ㎍/kg b.w/week, covered 0.32-2.08% of it.

In this work, the conventional transient liquid phase(TLP) bonding was modified. An attempt was made of using a liquid phase sintered alloy, which will be a liquid phase coexisting with a solid phase at the bonding temperature, as an interlayer for bonding metals. With an aim of revealing the fundamental features of this modified TLP bonding, the kinetics concerned with the growth of solid particles and the isothermal solidification process in Fe-1.16wt%B and Fe-4.5wt%P interlayers for the bonding pure iron, as well as the morphological change of the solid particle, were investigated.

중금속을 처리하는 방법에는 일반적으로 화학적, 물리적 그리고 생물학적 처리방법 등이 있다. 이중 생물학적 처리방법은 미생물들의 자연 생체기작을 이용하는 방법으로, 생체축적 (biosorption & bioaccumulation), 산화환원반응 (oxidation & reduction), 메칠화 및 탈메칠화반응 (methylation & demethylation), 금속 유기물질 복합반응 (metal-organic complexation)과 비용해성 복합

해조류의 최적생장 조건과 내성범위는 그 발달단계에 따라 다양하게 나타날 수 있다. 특히 초기 정착단계에서의 생장은 성체로의 성공여부를 결정하는데 있어 중요한 의미를 갖는다고 할 수 있다. 본 연구는 녹조 구멍갈파래 (Ulva pertusa)의 생식세포와 발아체를 이용하여 무기영양염류와 중금속이 발아와 발아체 생장에 미치는 영향을 알아보고 이들의 내성범위 및 최적조건을 구하고자 하였다. 먼저 광량에 따른 발아율은 동해와 서해해수 조건 모두에서 광량이 증가

The analysis of hazardous heavy metals, such as Pb, Cd and As, was conducted from the porcelain dinnerwares. Total 374 samples of those products in the domestic market were purchased for the study. All the samples were extracted by 4% acetic acid solution, followed by the analysis with AAS(Atomic Absorption Spectroscopy). As a result, Pb and As were detected maximum 8.63 ㎍/ml, 2.58 ㎍/ml, respectively. Cd was found in a sample as 0.10 ㎍/ml.

한강 고수부지 및 지천인 안양천, 탄천, 중랑천변의 경작지에서 채집된 36종 285건의 농작물에 대한 Pb, Cr, Cd, Fe, Zn, Mn, Cu. Hg의 농도를 측정하고 그 결과를 채집 시기, 채집 지역 및 작물별로 비교, 분석한 결과, 작물 중의 중금속 함량은 평균치를 기준으로 볼 때 Fe(34.592 ppm)>Mn(11.071 ppm)>Zn(8.853 ppm)>Cu(1.795 ppm)>Cr(0.237 ppm)>Pb(0.100 ppm)>Cd(0.011 ppm)>Hg(0.003 ppm) 순으로 곡류 및 두류에서는 Zn의 함량이 Mn보다 높고, 채소류와 과실류에서는 Mn의 함량이 Zn보다 높은 양상을 나타냈다. 또한 각 지역에서 채취한 작물의 미량금속 함량의 경우 Fe은 0.004∼203.083 ppm, Cu은 0.017∼22.727 ppm. Mn은 0.000∼74.373 ppm. Zn은 0.080∼37.166 ppm으로 비교적 고농도로 존재하고 있는 반면 유해중금속류인 Pb은 0.000∼0.654 ppm, Cd은 0.000∼0.270 ppm, Cr은 0.000∼l.229 ppm, Hg은 0.000∼0.037 ppm으로 비교적 미량으로 존재함을 알수 있었다. 대상 농작물을 잎, 줄기, 뿌리, 열매로 분류하여 미량금속 함량을 분석한 결과, 분석 대상 금속의 농도가 잎>줄기>뿌리>열매의 순으로 나타났다. 무등의 뿌리 작물에 있어서 Pb은 잎(0.055 ppm))뿌리(0.035 ppm), Cr은 잎(0.118 ppm))뿌리(0.031 ppm), Cd은 잎(0.004 ppm)1뿌리(0.001 ppm), Hg은 잎(0.004 ppm))뿌리(0.001 ppm)으로 뿌리보다 잎에 많은 것으로 나타났는데 이러한 결과로 보아 뿌리는 금속 이온이 흡수되는 기관일 뿐 축적은 잎에 비해 상대적으로 적게 됨을 알 수 있었다.

Fe-30Ni-0.35C 합금과 몇가지 저융점 순금속의 상변태에 미치는 압력의 영향에 대하여 PDSC를 이용하여 조사하였다. Fe-30Ni-0.35C 합금의 오스폼트 마르텐사이트 및 마르폼드 마르텐사이트 오스테나이트로 역변태시 압력이 1 기압에서 60기압으로 증가하에 따라. As점이 약 2~4˚C 저하하며, 이것은 상전이시의 체적변화가 음의 값이 되기 때문이다. 또한 Af 점은 압력이 증가함에 따라 변함없이 일정하거나 매우 미소한 상승을 나타내는데, 이것은 압력이 증가할수록 탄화물의 석출이 촉진되기 때문이다. Fe-30Ni-0.35C 합금의 오스폼드 마르텐사이트의 역변태시 엔탈피변화는 압력이 1 기압에서 60기압으로 상승함에 따라 10~14J/g 증가한다. 순금속 Se, Sn, Pb, Zn, Te 등의 용융점은 압력이 1기압에서 60기압으로 증가함에 따라 매우 완만하게 상승하며, 용융시의 엔탈피변화는 압력의 증가에 따라 거의 변화가 없거나 미소 증가를 나타낸다.

본 연구에서는 동해와 서해에서 채수된 자연해수에서 녹조 구멍갈파래를 배양하여 생장을 비교하고 아울러 환경오염인자라고 할 수 있는 무기영양염류(질산염과 인산염)와 중금속(구리와 납)의 영향을 평가하였다. 먼저, 광량별 생장율은 서해해수조건보다 동해해수조건에서 뚜렷하게 높게 나타났으며 이때 최적생장광량은 두 조건에서 공히 100μ molm-2 s-1인 것으로 나타났다. 엽록소 함량의 경우 60 μmolm­2S­1이하의

The effect of carbon content on the shape of WC grains dispersed in the Co-rich matrix during liquid phase sintering of WC-35%Co hard metals has been determined. The shape of WC grains was observed using SEM stereography after removing cobalt matrix with boiling hydrochloric acid solution. The WC grains changed from hexagonal to trigonal prism as the carbon content increased in the two-phase region of(WC + - Co), while the morphology of WC grains changed from trigonal to hexagonal shape as the carbon content decreased. The morphology of WC grains changes reversibly along with carbon loss or carbon pick-up. Morphology change of WC grains is attributed to crystal structure of WC, which has an asymmetric array of carbon atoms. There are two types of prismatic planes having different numbers of broken W-C bonds in WC grains. It is scrutinized that as the carbon content increases, the high energy prism planes grow fast and the crystals change from hexagonal to trigonal shape. On the other hand, when the carbon content decreases, the high energy prism planes are dissolved accompanying split of (100) plane into (101) and (101) planes.

활성금속브레이징법으로 계면접합된 AlN/Cu 접합체의 잔류응력 완화에 미치는 Mo 중간재의 영향을 조사하였다. 유한요소법에 의한 응력 해석과 접합체 강도 측정, 파단면의 관찰을 행하였으며, 이들 결과를 비교, 분석하였다. 응력 해석 결과로부터, Mo 중간재를 사용할 경우 최대 잔류 주응력이 형성되는 위치가 AlN/삽입금속 계면으로부터 삽임금속/Mo 계면을 통하여 Mo 내부로 이동됨을 확인하였다.접합체의 자유표면에 형성되는 인장성분의 응력집중 위치는 Mo 중간재 두께가 증가됨에 따라 Cu/Mo 계면과 Mo/AlN 계면의 두 곳으로 분리되었으며, AlN측 잔류응력의 크기는 크게 감소하였다. 중간재를 사용하지 않은 경우 최대 접합강도가 52 MPa로 낮은 강도를 보였으나, 두께 400μm 이상의 Mo 중간재를 사용한 접합체의 경우, 200 MPa 이상, 최대 275 MPa의 접합강도를 얻을 수 있었다.

Ag-Cu-Ti 삽입금속을 이용하여 제조된 AlN/Cu와 AlN/W 활성금속브레이징 접합체의 잔류응력을 유한요소법으로 탄성 및 탄소성 해석을 행하여 그 결과를 접합강도 측정 결과와 파단 거동 관찰 결과와 비교, 분석하였다. 최대 잔류 주응력의 크기는 AlN/W 접합체보다 모재간 열팽창계수 차이가 큰 AlN/Cu 접합체에서 더 크게 나타났으며, 접합계면에 인접한 AlN 세라믹스 자유표면에 인장 성분의 응력집중이 확인되었다. 모재와 삽입금속의 탄소성 변형을 모두 고려할 경우, AlN/Cu 접합체의 경우 연질의 삽입금속에 의해 최대 잔류 주응력이 감소하여 소성변형에 의한 응력완화 효과가 있음을 확인하였으나, 100μm 이상으로 삽입금속 두께를 증가시키더라도 잔류 주응력의 크기는 더 이상 크게 감소하지 않았다. 측정된 최대 접합강도는 AlN/Cu와 AlN/W 접합체에서 각각 52 MPa와 108 MPa이었으며, 파단 형태는 AlN/Cu 접합체는 AlN 자유표면으로부터 AlN 내부로 큰 각도를 이루면 진행되는 돔형의 파단이, AlN/W 접합체에서는 접합계면의 삽입금속층을 따라 AlN 측에서 파단이 일어나는 형태를 보였다.

The bioleaching of heavy metals from fly ash was performed by Thiobacillus thiooxidans MET isolated from the enrichment culture of an anaerobically digested sludge. The effect of solid concentrations on the efficiency of metal leaching was studied in shak

In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, Quercetin in the Onion ethanolic extract was affected as eliminator of the Mercury, Lead, and Cadmium.Abstracts In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, quercetin in the Onion ethanolic extract was affected as eliminator of the mercury, lead, and cadmium.