• Title/Summary/Keyword: Total metal content

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Physical Performance of Metallic Jacquard Fabrics (메탈릭 자카드 직물 물리적 성능평가)

  • Kang, Duck-Hee;Lee, Jung-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.1
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    • pp.149-159
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    • 2009
  • The purposes of this study are to evaluate physical performance of metallic Jacquard fabrics, and to contribute to the research and development of the women's suit made of the metallic Jacquard fabrics. First, eight fabrics were woven with two kinds of warp yarns(nylon and rayon) and weft yarn blended with various contents(0, 7, 14, 21%) of metallic yarn. Second, the mechanical properties were measured by using the KES-FB system, and physical properties such as tensile strength, tearing strength, abrasion resistance, drape, pilling, snagging, degree of crease resistance, flexural stiffness, specular gloss, folding endurance and electrostatic propensity were measured. The results were as follows. As the metal fiber content increased, bending, shear, thickness and weight increased, which imply low recovery of wrinkles. It means that metallic Jacquard fabrics enable to use as a memory fabric. 7% metallic Jacquard fabric showed a low value at total hand value, but there was little change. As the metal fiber content increased, tensile strength, tearing strength, drape coefficient, specular gloss and flexural stiffness increased, however the degree of crease resistance, electrostatic propensity and folding endurance decreased. The metallic Jacquard fabrics were excellent in snagging, abrasion resistance and pilling.

Contents of Heavy Metals in Leaf and Bark of Ginkgy biloba snd Platatus occidentalis and Soil of Roadside in Masan City (마산시 도로 주변 은행나무와 양버즘나무의 잎과 수피 및 토양의 중금속 함량)

  • Cheon, Seon-Hee;Jong-Hee Kim
    • The Korean Journal of Ecology
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    • v.19 no.3
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    • pp.241-249
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    • 1996
  • To determine the accumulation and distribution of heavy metals in plants and soils of roadsides, the leaf and bark of Ginkgo biloba and Platanus occidentalis, and the soil were sample from Masan-city roadside and Chinhae forest land in July and November, 1994. The content of heavy metals from all the samples in Masan-city area was much higher than that in Chinhae forest land. The amount of heavy metals in soil was higher than those in plant parts of boty trees. The total amount of heavy metals of the bark was higher than the leaf of G. biloba plants. But that of the bark was less than the leaf of P. occidentalis. Heavy metal content in plants (leaf, bark) varied among elements and collections. The concentrations of heavey metals in both trees were in the order of Zn > Cu > Pb > Cd. The concentrations of the four heavy metals in leaf and Zn in soil in G. Biloba were seasonally changed. Whereas those in P. occidentalis were not significantly changed. And there was a high correlation between the concentrations of Pb and Cu in both trees.

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Comparisons of Simple Extraction Methods and Availability for Heavy Metals in Paddy Soils (토양 중금속의 단일침출방법과 유효도 비교)

  • Jung, Goo-Bok;Kim, Won-Il;Moon, Kwang-Hyun;Ryu, In-Soo
    • Korean Journal of Environmental Agriculture
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    • v.19 no.4
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    • pp.314-318
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    • 2000
  • To compare heavy metal phytoavailability in paddy soils near five abandoned mining areas, 4 different soil extractants such as 0.1M-HCl, $0.1M-HNO_3$, 0.05M-EDTA, and 0.005M-DTPA were used. Total acid digestion method $(H_2SO_4:HClO_4:HNO_3)$ was also employed to analyze heavy metal content in 30 paddy soils and brown rice. The rates of extracted heavy metal to total content were in the range of $12.1{\sim}39.1%$ for Cd, $20.5{\sim}45.5%$ for Cu, $10.6{\sim}30.7%$ for Pb, and $6.7{\sim}13.0%$ for Zn. 0.1M-HCl and $0.1M-HNO_3$ extractable both Cu and Pb were relatively less extracted at the high soil pH and extractable calcium site(Mine D) whereas 0.05M-EDTA and 0.005M-DTPA extractable Pb were strongly extracted at the same soils. In case of Cd, Cu, and Zn in soil, 4 types of extractable heavy metals and total content were highly correlated with each other. However, there were positive correlations between 0.1 M-HCl and $0.1M-HNO_3$ extractable Pb as well as between 0.05M-EDTA and 0.005M-DTPA extractable Pb, which were relatively similar extractants in chemical properties. The rates of heavy metals in brown rice to total contents in soils were in the order Zn>Cd>Cu>Pb. Specially, the rate of Cd, Pb, and Zn were lower at the highest level of soil pH and Ex. Ca. Both Cd and Zn in brown rice were positively correlated with those of all soil extractants. It was estimated that the solubility following to the plant uptake of Cd and Zn were higher than those of Cu and Pb considering relationships between all kinds of heavy metal contents in soil and those in brown rice.

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Biomonitoring of Metal Exposure During Additive Manufacturing (3D Printing)

  • Ljunggren, Stefan A.;Karlsson, Helen;Stahlbom, Bengt;Krapi, Blerim;Fornander, Louise;Karlsson, Lovisa E.;Bergstrom, Bernt;Nordenberg, Eva;Ervik, Torunn K.;Graff, Pal
    • Safety and Health at Work
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    • v.10 no.4
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    • pp.518-526
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    • 2019
  • Background: Additive manufacturing (AM) is a rapidly expanding new technology involving challenges to occupational health. Here, metal exposure in an AM facility with large-scale metallic component production was investigated during two consecutive years with preventive actions in between. Methods: Gravimetric analyzes measured airborne particle concentrations, and filters were analyzed for metal content. In addition, concentrations of airborne particles <300 nm were investigated. Particles from recycled powder were characterized. Biomonitoring of urine and dermal contamination among AM operators, office personnel, and welders was performed. Results: Total and inhalable dust levels were almost all below occupational exposure limits, but inductively coupled plasma mass spectrometry showed that AM operators had a significant increase in cobalt exposure compared with welders. Airborne particle concentrations (<300 nm) showed transient peaks in the AM facility but were lower than those of the welding facility. Particle characterization of recycled powder showed fragmentation and condensates enriched in volatile metals. Biomonitoring showed a nonsignificant increase in the level of metals in urine in AM operators. Dermal cobalt and a trend for increasing urine metals during Workweek Year 1, but not in Year 2, indicated reduced exposure after preventive actions. Conclusion: Gravimetric analyses showed low total and inhalable dust exposure in AM operators. However, transient emission of smaller particles constitutes exposure risks. Preventive actions implemented by the company reduced the workers' metal exposure despite unchanged emissions of particles, indicating a need for careful design and regulation of the AM environments. It also emphasizes the need for relevant exposure markers and biomonitoring of health risks.

Free Radical Scavenging Activity and Protective Ability of Methanolic Extract from Duchesnea indica Against Protein Oxidation and DNA Damage

  • Hu, Weicheng;Shen, Wei;Wang, Myeong-Hyeon
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.277-282
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    • 2009
  • The antioxidant potency of methanolic extract of Duchesnea indica (MDI; Indian strawberry) was investigated by employing various established in vitro systems, such as total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power assay, metal chelating assay, superoxide radical scavenging activity and protective ability of DNA damage and protein oxidation. MDI inhibited metal chelating by 75.57% at 2 mg/mL, scavenged 50% DPPH free radical at 29.13 ${\mu}$g/mL, and eliminated approximately 46.21% superoxide radical at the concentration of 1 mg/mL. In addition, MDI showed strong ability on reducing power, DNA damage protection and protein oxidation protection. Overall, results suggested that MDI might be beneficial as a potent antioxidant and effectively employed as an ingredient in food applications.

A Study on Applicability of Carbon Ceramic Disc using Pretreated Carbon Fiber (전처리된 탄소섬유를 이용한 카본 세라믹 디스크 적용 가능성에 대한 연구)

  • Yoo, Tae-Doo;Kim, Hong-Gun;Kwac, Lee-Ku
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.4
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    • pp.39-45
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    • 2022
  • In this study, it was verified that carbon-ceramic brake discs can replace existing cast-iron brake discs of the same size. In addition, a method of pretreating carbon fiber to secure heat dissipation characteristics while using a small amount of carbon fiber was established. The thermal conductivity and bending strength characteristics were analyzed according to the carbon content, and brake braking tests were conducted. Through pretreatment, the maximum temperature was lowered by 16 ℃ compared to the case using only carbon fiber, and the cooling rate was improved by approximately 10% compared to metal brake discs. However, the total heat capacity increased as the mass increased owing to the reaction. Thus, the measured temperature was higher than that of the metal brake disc; therefore, additional research is required.

Changes of Nitrogen Fixation Activity and Heavy Metal Accumulation of Vicia amoena Community from Kumho Riverside (금호강유역 갈퀴나물군락의 중금속 축적과 질소고정 활성의 변화)

  • 박태규;박용목;송은주;송승달
    • The Korean Journal of Ecology
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    • v.22 no.3
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    • pp.131-137
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    • 1999
  • This study was carried out to investigate the activity of nitrogen fixation and accumulation of heavy metal and inorganic matter in Vicia amoena community at lower region in Kumho riverside, including Youngchon, Chimsangyo, Paldalgyo, Talseochon and Kumhogyo. The contents of inorganic matter and heavy metal of Kumho riverside soil increased in the down stream in each organ of the plant growing in the riverside. Generally, V. amoena community showed rapid growth of shoot and high value of Top/Root ratio. V. amoena community showed higher water content of shoot at late growth stage and higher chlorophyll content. The root nodule of V. amoena community appeared in April and increased by 0.30, 0.27, 0.24, 0.06 and 0.14 g/plant, and nitrogen fixation activity of nodule attained 20.1, 16.8, 15.4, 8.5 and 5.3 μmol·C₂H₄·g fw nodule/sup -1/·h/sup -1/ for non-contaminated area Youngchon, Chimsangyo, Paldalgyo, Talseochon and Kumhogyo, respectively, in June:. Nodule formation and nitrogen fixation activity were reduced in the down stream by the soil contamination and heavy metal accumulation and showed minimum values. at Talseochon and Paldalgyo. V. amoena showed growth adaptation against heavy metal toxicity by restricting heavy metal such as Pb, Cu, Zn, Fe from transport, and by accumulating high Ca ion in shoot, nitrogen and phosphorus in root at late growth stage than those at early one, respectively, but total heavy metal per plant showed higher values in shoot than those in root by high T/R ratio of plant growth.

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The effects of heavy metals on microbial biomass and activity in contaminated urban park soils (도시 공원의 토양에서 중금속이 미생물의 생체량과 활성에 미치는 영향)

  • Kim, Ok-Kyung;Paul Birch
    • The Korean Journal of Ecology
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    • v.15 no.3
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    • pp.267-279
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    • 1992
  • The relationship between pb, zn, cd, and the microbial biomass and activity were investigated in three public park soils of central and outer london. Variability with distance from the roadside and profile were studied. The heavey metal concentrations were the highest in hampstead heath and hyde park with high trafic density and the lowest in hainault. The highest concentrations of heavy metals were found adjacent to the roadside in the upper parts of the soil profile. Dehydrogenase activity, adenosine tri-phosphate and ergosterol contents used as indices of micrbial biomass and activity, were generally higher in hainadult, and also higher in the upper pats of the soil profile. Simple regression analysis indicated that the microbial biomass and activity were affected significantly by moisture content, water holding capacity, total organic carbon, total nitrogen, and organic mater rather than heavy metal concentration. Highest inputs of nitrogen and carbon were associated with high inputs of heavey metals, all three being derived from vehicle emissions adjacent to the road. The hyde park and hampstead heath microbial populations were able to respond to the c and n input positively by increase in biomass and activity, whereas the hainault populations could not. This rsult suggrsts adaptation in he former to heavy matals, but not in the latter.

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Food Hazard Analysis During Dried-laver Processing

  • Son, Kwang-Tae;Lach, Thea;Jung, Yeounjoong;Kang, Shin-Kook;Eom, Sung-Hwan;Lee, Dae-Sung;Lee, Myung-Suk;Kim, Young-Mog
    • Fisheries and Aquatic Sciences
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    • v.17 no.2
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    • pp.197-201
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    • 2014
  • This study was performed to identify and assess food hazards during dry laver processing. Samples including raw materials, intermediates, and finished products during dried-laver processing were collected from seven dried-laver processing facilities, and microbial analyses were conducted. Microbial levels such as total coliforms and total viable cell count (TVC) increased as the processing steps progressed. TVC and total coliforms ranged from <30 to $9.1{\times}10^7$ CFU/g and <18 to 27,600 MPN/100 g for intermediates and finished products obtained during dried-laver processing, respectively. However, no fecal coliform was detected in the samples. Additionally, food-borne bacteria including Bacillus cereus, Listeria monocytogenes, Salmonella sp., Staphylococcus aureus, and Vibrio parahaemolyticus were not identified in finished products. For heavy metal content, arsenic ranged from 30.18 to 39.05 mg/kg, mercury from 0.005 to 0.009 mg/kg, and cadmium from 0.076 to 0.318 mg/kg dry mass in all finished products. However, lead was not detected in samples tested in this study. In conclusion, dried-laver products were safe based on the levels of food-borne bacteria and heavy metal contents. However, it is important to reduce total viable cell counts and total coliforms during dried-laver processing.

Sequential Extraction of Cadmium, Zinc, Copper and Lead in Soils near Zinc-mining Sites (아연광산(亞鉛鑛山) 주변(周邊) 토양중(土壤中) 카드뮴, 아연(亞鉛), 구리 및 연(鉛) 화학적(化學的) 형태별(形態別) 함량(含量))

  • Yoo, Sun-Ho;Kim, Kye-Hoon;Hyun, Hae-Nam
    • Korean Journal of Environmental Agriculture
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    • v.4 no.2
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    • pp.71-77
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    • 1985
  • Soil samples collected from paddy field adjacent to zinc-mining sites were sequentially extracted to assess chemical fractions of Cd, Zn, Cu and Pb. The purpose of this study was two fold; (i) to examine the chemical forms of heavy metal in soils by sequential extraction. and (ii) to determine relationships between the chemical distribution of heavy metal in the soil and the heavy metal content of the brown rice. The results are summarized as follows. The content of exchangeable, organically bound and carbonate Cd and residual Zn was 73.9% and 63.8% of total Cd and Zn in the soil, respectively. The content of exchangeable Cd, Zn and Pb in soil showed highly negative correlations with pH, organically bound Cd, carbonate Cd, sulfide Cd, Zn and Pb in soil showed highly positive correlations with pH. The content of organically bound Cd, Zn, Pb and carbonate Cu in soil showed highly positive correlations with organic matter content, while the content of sulfide Cu and residual Cd in soil showed highly negative correlation with organic matter content. The content of carbonate Cd, Zn, Pb and residual Cu in soil showed highly positive correlations with CEC, but the content of exchangeable Cd, Zn, Cu, Pb and organically bound Cu in soil showed highly negative correlations with CEC. The content of total, organically bound, carbonate, sulfide and residual Cd in soil were highly correlated with that of Cd in brown rice. The content of any Pb fractions in soil were not correlated with that of Pb in brown rice. The content of water soluble and exchangeable Zn in soil were highly correlated with that of Zn in brown rice.

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