• 제목/요약/키워드: trace elements

검색결과 729건 처리시간 0.029초

Effect on Milking Performance of Vitamin-Trace Element Supplements to Early Lactation Italian Brown Cows Grazing Ryegrass (Lolium multiflorum) Pasture

  • Tufarelli, Vincenzo;Khan, R.U.;Laudadio, V.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권9호
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    • pp.1227-1232
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    • 2011
  • The objective of this study was to examine the effects of concentrates containing different levels of a vitamin-trace elements premix on milk yield and composition of dairy cows. The trial, which lasted 14 weeks, was conducted from January to March and used 45 multiparous Brown cows in the early phase of lactation. Cows (n = 15 per treatment) were randomly allocated to three dietary treatments: the first group (control, C-0) was fed pelleted concentrate containing background vitamins and trace elements that supplied 1.0 times cows' daily requirements; the second group were fed the same concentrate, but containing 2.5 g/kg of vitamin and trace mineral premix per kg of concentrate (C-2.5); the third group were fed the same concentrate, but containing 5 g/kg of vitamin and trace mineral premix per kg of concentrate (C-5). The daily ration included ad libitum chopped oat hay, and the cows also had 8 h/d grazing on a ryegrass (Lolium multiflorum) pasture. During the performance trial, cow milk yield was daily recorded and individual milk samples were analysed for milk composition and to determine milk renneting properties. Cows fed the intermediate premix level (C-2.5) in diet showed the highest fat-corrected milk production (p<0.05) compared to other groups. None of the milk quality parameters studied were influenced by dietary treatment, except for milk rheological parameters (rennet clotting time and curd firmness) that were positively improved in cows fed the C-2.5 diet (p<0.05). The findings from this study show that intermediate level of vitamin-trace elements premix in concentrate can be advantageously used in grazing dairy cows without negative effects on yield and quality of milk produced.

중성자방사화분석법에 의한 이산화우라늄중의 불순물정량 (Determination of Impurities in Uranium Dioxide by Neutron Activation Analysis)

  • Nak Bae Kim;Hae-Ill Bak;Chul Lee
    • Nuclear Engineering and Technology
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    • 제13권4호
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    • pp.237-244
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    • 1981
  • 이산화우라늄중의 미량불순물원소들의 중성자 방사화분석을 위하여 이들 원소들의 사전농축에 음이온교환수지를 사용하였다. 황산에 녹인 우라늄 시료용액의 산도를 pH 2.7에 맞춘다음 음이온교환수지통에 얹었다. 이 음이온교환수지통으로 부터 미량분순물 원소만을 정량적으로 회수할 수 있었다. 이 사전농축법과 알미늄중 미량불순물 원소의 정량을 위하여 개발한 방사화학적인 분리법을 이용하므로서 원자로급 이산화우라늄 중의 21개 미량불순물을 정량할 수 있었다.

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흑연로 원자흡수분광광도법에 의한 뇨시료 중 흔적량 원소의 정량 (Determination of Trace Elements in Urine Samples by Graphite Furnace Atomic Absorption Spectrophotometry)

  • 최종문;최희선;박창준;김영상
    • 분석과학
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    • 제7권4호
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    • pp.555-561
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    • 1994
  • A method was described for the graphite furnace atomic absorption spectrophotometric determination of trace cadmium, copper, chromium and lead in urine samples. The elements were directly determined without any other treatments. The ash temperature was intensively optimized to improve the large background by the removal of organic materials and alkali and alkali earth metals in urine samples. Two kinds of standard solutions were used to plot calibration curves. From the recovery data, it could be confirmed that the analytical results with the synthetic urine matrix similar to real urine were more accurate than with a deionized water matrix.

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A Study on the Present Levels of Mercury and other Trace Elements in Fresh-water Fish by Neutron Activation Analysis

  • Kim, Nak-Bae;Lee, Chul;Bak, Hae-Ill
    • Nuclear Engineering and Technology
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    • 제8권1호
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    • pp.41-47
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    • 1976
  • Ge(Li) 검출기를 사용한 비파괴 방사화분석법을 이용하여 담수어중 수은 및 기타 미량원소들의 현재 함량 준위를 조사하다. 분석결과에 의하면 지역에 따라 수은의 함량이 크게 변하였으며 이 변화는 아마 지역적인 오염원에 의한 것으로 생각된다. 그리고 분석결과로 부터 미량원소들 중 어떤 원소들 사이에는 뚜렷한 상관관계가 있음을 알았다. 수은 오염의 중요한 원인으로 무연탄 연소가 고려될 수 있을 것으로 생각되어 수종의 무연탄을 분석하였다.

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대구지역 도로먼지에 함유된 미량원소성분과 오염원 평가 (Trace Elements and Source Assessment of Street Dust in Daegu, Korea)

  • 송희봉;이은영;도화석;정철수;신동찬;이명숙;백윤경;전성숙;신원식
    • 대한환경공학회지
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    • 제29권7호
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    • pp.793-800
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    • 2007
  • 2006년 4월과 5월에 대구지역의 도로먼지로 채취한 총 48개의 시료를 100 ${\mu}m$ 이하로 체거름하고 산추출한 후 ICP로 14개 원소를 분석하였다. 농축계수를 이용한 미량원소성분의 발생원 평가결과, Ca, Fe, K, Mg, Mn, Na, V의 성분은 토양과 먼지와 같은 자연적 발생원에 의한 영향을 받고 있는 반면에 Cd, Cr, Cu, Ni, Pb, Zn의 성분은 연료연소와 폐기물소각과 같은 인위적 발생원에 의한 영향을 받고 있었다. 분석결과는 자연적 발생원과 관련된 성분이 인위적 발생원과 관련된 성분보다 매우 높은 농도를 보였다. 도로먼지에 함유된 미량원소성분은 대구지역이 외국의 다른 도시보다 대체로 더 높은 수준을 보였다. 미량원소성분의 농도와 중금속의 오염지수는 공업지역과 상업지역이 주거지역과 녹지지역보다 높았다. 그리고 미량원소성분간의 상관성 분석결과, 인위적 발생원과 관련된 성분간에는 유의한 상관성이 많았던 반면에 자연적 발생원과 관련된 성분간에는 유의한 상관성이 적었다. 게다가 교통량과 인위적 발생원과 관련된 성분간에도 유의한 상관성을 보였다.

Skaergaard 암체의 희토류의 분화경향 (Differentiation Trend of Rare Earth Elements of the Skaergaard Intrusion)

  • Yun D. Jang
    • 자원환경지질
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    • 제34권6호
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    • pp.617-625
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    • 2001
  • Skaergaard 암체는 광범한 in situ 화성분화작용을 격은 층상관입암의 대표적인 예로 널리 알려져 있다. 따라서 이 암체는 폐쇄계에서 미량원소변이를 modeling 할 수 있는 적지가 될 것이다. 그러나, 기존의 연구에 의하면 본 암체의 전암 및 광물의 회토류는 폐쇄계로서의 예상된 경향을 보이지 않는다(Haskin and Haskin, 1968; Paster et al., 1974). 발표된 분배계수, 공존광물들의 mode,그리고 전암 및 광물의 미량원소함량을 사용한 미량원소modeling에 의하면 Skaergaard 암체의 희토류는 분화후기에 일어난 광범한 인회석 결정작용에 크게 영향을 받았음을 보여준다. 미량원소modeling은 Upper Border Series에서 간헐적으로 나타나는 인회석이 기존에 주장되어 온 바와 같은 liquldus상이 아니라 진화하는 magma의 미량원소함량에는 영향을 끼칠 수 없는 interstitial phase임을 시사한다. 분화작용 말기에 Skaerganrd 마그마가 대류를 멈추거나 소규모로 대류를 할 때, 마그마 암장의 상부에 축적되는 휘발성분에 기인한 증가된 $PH_2$O가 인회석이 UBS에서 정출 되는 것을 방해하였을 것이다. 이와 같은 인회석의 특성을 고려해서 Skaergaard분화작용을 modeling하면 희토류는 폐쇄계로서의 예상된 경향을 따른다 이와 같은 결과는 최종 20% 분화작용기간 중에 양적으로 상당한 양의 마그마의 주입이나 분출을 수반하는 그 어떤 Skaergaard 암체의 분화model도 배격한다.

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Comparison of USEPA Digestion Methods for Trace Metal Analysis Using SRM

  • Shin, Mi-Young;Yoon, Hyeon;Kim, Youn-Tae;Yoon, Cheol-Ho;Woo, Nam-Chil
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.223-226
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    • 2004
  • The importance of a proper sample preparation and analysis technique has getting attention due to the complicity of toxic elements of interest from environmental samples depend on analytical purposes. It is critical to use proper analytical method to evaluate trace elements concentration in many environmental samples especially for making remediation decisions. Therefore, it is critical to apply a proper sampling and analytical method such as EPA publication SW-846 (Test Methods for Evaluating Solid Waste, Physical/chemical Methods). The objective of this study was to compare the USEPA Methods 3050B, modified 3050B, 305 la, and KBSI method (modified EPA 3052 Method) in term of recovery rate of metals. The NIST SRM (Montana soil) was used to compare the extraction and digestion efficiency. After sample has been collected the analysis were achieved by ICP-MS (Elan 6100, Perkin Elmer) as well as ICP-AES (Ultima 2C, JY) for trace elements and major elements.

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중성자방사화분석에 의한 Algae중의 독성미량원소의 정량 및 실험실간 비교검증 (Data intercomparison and determination of toxic and trace elements in Algae using Instrumental Neutron Activation Analysis)

  • 정용삼;문종화;박광원;이길용;윤윤열
    • 분석과학
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    • 제12권4호
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    • pp.346-353
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    • 1999
  • For the non-destructive multi-elemental analysis of environmental and biological materials, instrumental neutron activation analysis (INAA) was applied for the determination of toxic and trace elements in a set of three Algae samples provided by the International Atomic Energy Agency (IAEA). The analytical quality control was evaluated by comparing the analytical results of two standard reference materials of the National Institute of Standards and Technology (NIST); Oyster Tissue (SRM 1566a) and Citrus Leaves (SRM 1572). According to given analytical procedure, the concentration of 15-25 elements including spiked elements such as As, Cd, Cr and Hg in Algae samples were determined. To identify and validate these results, a data intercomparison program using more than 35 analytical methods in 150 laboratories was carried out and the estimated statistical data are summarized. Result of INAA is favorable, therefore, it is illustrated that can be applied for routine analysis of essential and toxic elements in algae samples as well as analytical quality assurance.

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Organic Precipitate Flotation of Trace Metallic Elements with Ammonium Pyrrolidinedithiocarbamate (II). Application of Solvent Sublation for Determination of Trace Cd, Co, Cu and Ni in Water Samples

  • 김영상;정용준;최희선
    • Bulletin of the Korean Chemical Society
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    • 제19권1호
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    • pp.50-56
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    • 1998
  • A solvent sublation was studied for the determination of trace Cd, Co, Cu and Ni in water samples. Ammonium pyrrolidine dithiocarbamate (APDC) was used as a complexing agent. Experimental conditions such as pH of solution, amounts of APDC, the type and amount of surfactant, the type of solvent, etc. were optimized for the effective sublation of analytes. After metal-PDC complexes were formed in sample solutions of pH 2.5, the precipitate-type complexes were floated in a flotation cell with an aid of sodium lauryl sulfate as a surfactant and by bubbling with nitrogen gas. The precipitates were dissolved and separated into the surface layer of methyl iso-butyl ketone (MIBK). The analytes preconcentrated were determined by a graphite furnace atomic absorption spectrophotometry (GF-AAS). Extractability of each element was 88% for Cd(Ⅱ), 86% for Co(Ⅱ), 95% for Cu(Ⅱ) and 76% for Ni(Ⅱ), respectively. And this procedure was applied to the analysis of real samples. From the recoveries of more than 92%, it was concluded that this method could be simple and applicable for the determination of trace elements in various water samples of a large volume.