• 제목/요약/키워드: minerals.

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천연 무기 광물계 혼화재료를 혼입한 철근콘크리트 구조물의 부식저항성에 관한 연구 (A Study on Corrosion Resistance of Reinforced Concrete Structures using Natural Inorganic Minerals)

  • 태성호;박재영;김재영;박재승;경제운;남호윤
    • KIEAE Journal
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    • 제7권4호
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    • pp.127-133
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    • 2007
  • As a fundamental study on the corrosion resistance of reinforced concrete structures using Natural Inorganic Minerals exposed to carbonation environment, The test specimens were concrete(W/C=60%) with Natural Inorganic Minerals content of 0%, 10%. Accelerated carbonation and autoclave corrosion accelerated curing were then conducted with them. The corrosion resistance of steel in concrete with Natural Inorganic Minerals content of 0%, 10% was examined by corrosion form, half-cell potential, polarization resistance, corrosion area and weight loss after 24 hours of autoclave corrosion accelerated curing.The results of the study showed that as for steel in concrete with Natural Inorganic Minerals content of 10%, the corrosion resistance was more excellent than steel in concrete with Natural Inorganic Minerals content of 0%.

Effects of Organic Trace Mineral Supplementation on Sows' Reproductive and Neonates' Growth Performance through 2 wk Postweaning

  • Acda, S.P.;Chae, B.J.
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권9호
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    • pp.1312-1318
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    • 2002
  • A feeding trial using sows and their neonates was conducted to determine the effects of source and level of organic trace mineral supplementation on reproductive performance of sows and the subsequent performance of their neonates through 2 wk post weaning. A total of 16 gestating sows ($Landrace{\times}$Yorkshire) in parities 2 to 4 were randomly assigned to 4 dietary treatments following a $2{\times}2$ factorial arrangement in a completely randomized design. One of the two factors evaluated the effect of the source (inorganic vs organic), and the second factor evaluated the effect of the level (low vs high) of trace minerals added to the diet. The trace mineral premixes were formulated to provide a low concentration of trace minerals (50 ppm Fe/87.5 ppm Fe, 17.5 ppm Cu/85 ppm Cu, 45 ppm Zn/60 ppm Zn, and 20 ppm Mn/17.5 ppm Mn), and a high concentration of trace minerals (100 ppm Fe/175 ppm Fe, 35 ppm Cu/170 ppm Cu, 90 ppm Zn/120 ppm Zn, 40 ppm Mn/35 ppm Mn), when included at 0.20% in sows'/weaned pigs' diets, respectively. The total number born, total born alive and weaned, and the average neonate weight at birth were affected neither by the dietary source nor by the level of trace minerals (p>0.05), but an interaction effect (p<0.05) between the source and level of trace minerals was observed on the average weight at weaning. The neonates from sows fed the low level of organic trace minerals gained weight at an equal rate compared with those farrowed by sows fed the high level of inorganic trace minerals. Sows fed the organic trace minerals nursed their young with milk higher in Fe and Zn (p<0.05) compared with those fed diets with inorganic trace minerals. Consequently, the weaned pigs receiving the organic form of trace minerals tended to grow at a faster rate, consumed less feed and tended to utilize their feed more efficiently (p<0.10). It was further observed that the organic trace minerals significantly increased (p<0.05) Fe contents in the liver and serum, and Zn in the serum and bone. In conclusion, sows and neonates fed the organic minerals at low level showed similar performance compared with those fed the inorganic minerals at high level as specified in this study.

Thermoluminescence (TL) of Minerals Separated from Irradiated Mussel

  • Yi, Sang-Duk;Oh, Man-Jin
    • Preventive Nutrition and Food Science
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    • 제10권1호
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    • pp.17-21
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    • 2005
  • This study was carried out to determine whether detection of minerals separated from irradiated mussel could be could be done by thermoluminescence (TL) method. After the minerals were separated by sodium polytungstate solution (2.0 g/mL) from irradiated mussel, organic compounds remaining in the minerals were removed by acid-base treatment and dried at 50℃ overnight, and then the minerals were measured through TL. The TL intensities of separated minerals at different irradiation doses during storage conditions of room and darkroom were obtained. TL intensity of first glow curves for minerals separated from irradiated mussel showed linear increase from the control to 5 kGy and slight increase from 5 kGy to 10 kGy. Since glow curve ratios of G2, G3 and G4, calculated from re-irradiated minerals measured immediately after irradiation and after storage of three months were over 0.5, detection of irradiation was possible. G1, which showed the glow curve ratios above 0.1, was classified as non-irradiated samples because the unique first glow curve was not found within the recommended temperature interval (150-230℃). Hence, on the basis of TL intensity, and glow curve ratio and shape, it is possible to correctly identify irradaited mussels after mineral separation during storage.

Removal of Arsenic(V) from Aqueous Solutions by Using Natural Minerals

  • Mohapatra Debasish;Mishra Debaraj;Chaudhury G. Roy;Das R.P.;Park, Kyung-Ho
    • 자원리싸이클링
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    • 제15권5호
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    • pp.38-46
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    • 2006
  • The removal of arsenic(V) using four different natural minerals were evaluated. Parameters like contact time, pH, adsorbent dosages, and As(V) concentration were optimized. The kinetics of adsorption was observed to be fast and reached equilibrium within 2h. As(V) adsorption on studied minerals was dependent on pH and followed a pseudo-second-order reaction model. For kaolin, maximum adsorption was found at pH 5.0. Whereas, in case of other three minerals, a pH range of 6.0-7.0 was found to be the best for As(V) adsorption. The maximum adsorption capacity (Q) was calculated by fitting Langmuir equation to the adsorption isotherms obtained under a specified condition. From the slope of best fit, the Q values were calculated to be 2.07, 2.15, 1.95 and 0.86 mg As(V)/g of bauxite, wad, iron ore and kaolin, respectively. Desorption of As(V) from loaded materials was dependent on the type of leaching reagents used. Based on the results, it was found that among the studied natural minerals, wad was the best As(V) adsorbent.

Effects of neutron irradiation on densities and elastic properties of aggregate-forming minerals in concrete

  • Weiping Zhang;Hui Liu;Yong Zhou;Kaixing Liao;Ying Huang
    • Nuclear Engineering and Technology
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    • 제55권6호
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    • pp.2147-2157
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    • 2023
  • The aggregate-forming minerals in concrete undergo volume swelling and microstructure change under neutron irradiation, leading to degradation of physical and mechanical properties of the aggregates and concrete. A comprehensive investigation of volume change and elastic property variation of major aggregate-forming minerals is still lacking, so molecular dynamics simulations have been employed in this paper to improve the understanding of the degradation mechanisms. The results demonstrated that the densities of the selected aggregate-forming minerals of similar atomic structure and chemical composition vary in a similar trend with deposited energy due to the similar amorphization mechanism. The elastic tensors of all silicate minerals are almost isotropic after saturated irradiation, while those of irradiated carbonate minerals remain anisotropic. Moreover, the elastic modulus ratio versus density ratio of irradiated minerals is roughly following the density-modulus scaling relationship. These findings could further provide basis for predicting the volume and elastic properties of irradiated concrete aggregates in nuclear facilities.

Utilization of Dietary Nutrients, Retention and Plasma Level of Certain Minerals in Crossbred Dairy Cows as Influenced by Source of Mineral Supplementation

  • Gowda, N.K.S.;Prasad, C.S.;Ashok, L.B.;Ramana, J.V.
    • Asian-Australasian Journal of Animal Sciences
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    • 제17권2호
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    • pp.221-227
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    • 2004
  • Nutrient utilization and plasma level of minerals were studied in lactating crossbred cows fed diet supplemented from different source of minerals. Twelve crossbred cows of first to third lactation during their mid stage of lactation were distributed equally under two groups and were fed concentrate mixture, green fodder (para grass) and finger millet straw as per requirement. Cows in group I were fed concentrate mixture supplemented with 1% mineral mixture whereas cows in group II were not supplemented with mineral mixture in the concentrate mixture but were offered additional quantity of green fodder (1 kg DM/cow/day) to compensate for the requirement of minerals. Balance study conducted towards the end of 120 days of feeding experiment indicated that the total dry matter intake in both the groups did not differ significantly. The cows in group II offered additional quantity of green fodder consumed significantly (p<0.05) more of green fodder (5.11 vs. 4.51 kg /animal/day) and the cows in group I consumed significantly (p<0.01) more of finger millet straw (1.71 vs. 0.92 kg/animal/day). The digestibility of major nutrients did not differ between the groups except for ether extract which was significantly (p<0.05) lower in cows fed additional green fodder. The total daily intake of P, Cu, Fe and Co did not differ significantly in both the groups whereas significantly higher intakes of Ca, Mg, Zn and Mn were observed in cows supplemented with inorganic source of minerals. However, supplementation through both the sources could meet the mineral requirement in group I and group II. The gut absorption (%) of all the minerals was comparable between the groups except for Mg which was significantly (p<0.05) higher in cows supplemented mineral mixture. The net retention of all the minerals was significantly more in the group supplemented with inorganic source of minerals. Except for P, Mg and Co the retention as percentage of total intake was comparable for all minerals in both the groups. Irrespective of source of mineral supplementation the average monthly blood plasma mineral levels (Ca, P, Mg, Cu, Zn, Fe) were within the normal range and comparable between the groups. Lower level of Cu observed at the start of the experimental feeding in both the groups increased with the advancement of supplemental feeding. The plasma Zn and Fe content in cows of both the groups did not vary. The blood plasma level of some minerals (Ca, P, Mg and Cu) was significantly higher towards the end of experimental feeding as compared to the initial values due to the reduction in milk yield with advancement of lactation or due to supplemental effect of minerals. It could be concluded that supplementation of minerals through inorganic source is better utilized in terms of retention as compared to green fodder (para grass), which is a moderate source of most nutrients.

지하매질에서의 방사성핵종흡착: 단일광물의 역할 (Radionuclide Sorption in the Geosphere: Role of Single Minerals)

  • Cho, Young-Hwan;Hyun, Sung-Pil;Hahn, Pilsoo
    • 한국광물학회:학술대회논문집
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    • 한국광물학회.한국암석학회 2001년도 공동학술발표회 논문집
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    • pp.40-40
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    • 2001
  • The sorption behavior of Cs(I), Sr(II), and U(VI) on representative single minerals(oxide and clay) and rocks were comparatively studied by using batch type sorption experiment. The effects of pH, ionic strength and the sorption mechanism were also discussed. It was found that mineral structure played as a main factor governing the sorption characteristics of Cs(I), Sr(II). The sorption of Cs(I) and Sr(II) on minerals showed ionic strength-dependency, which is a indirect sign of weak binding between metal cation and mineral surfaces. However, the sorption behavior of U(VI) was quite different compared with that of Cs(I), and Sr(II). Fe-oxide minerals showed strong tendency for U(VI) sorption, dominating the sorption in the composite/mixture systems. The surface characteristics which arise from mineral structure, and the affinity of metal ions to the sorption sites of minerals are the key to understand the role of minerals in the radionuclide sorption.

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Inhibitory Effect of Ore Minerals on the Allergic Inflammation in Mouse

  • Park, Seul-Ki;Lee, Chang-Won;Lee, Mi-Young
    • Applied Biological Chemistry
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    • 제51권4호
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    • pp.269-275
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    • 2008
  • The ore minerals, mainly composed of sericite, talc, and halloysite, were investigated for their inhibitory effect on the allergic inflammation in mice by measuring the serum IgE level, inflammatory cytokine production, and histamine and ${\beta}$-hexosaminidase releases. When the mice were ovalbumin (OVA)-challenged prior to the ore mineral treatment, the IgE level in the serum decreased significantly. The ore minerals significantly reduced the productions of IL-4 and the tumor necrosis factor-${\alpha}$ in the bronchial alveolar lavage fluid challenged with OVA. The inflammatory infiltrates, found in the lung of the OVA-challenged mouse, were also notably decreased following the ore mineral treatment. The ore minerals significantly reduced the release of histamine and ${\beta}$-hexosaminidase from the RBL-2H3 cells. These results suggest that the ore minerals may be useful as potent inhibitors of the allergic inflammation in mice.

Effect of Structural Type of Clay Minerals on Physical Properties of Mountainous Grassland Soils

  • Choi, Seyeong;Park, Man
    • 한국토양비료학회지
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    • 제49권6호
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    • pp.807-812
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    • 2016
  • Soil amendment, especially addition of clay minerals, has been widely conducted to improve the physical and chemical properties of cultivated soils. However, there are no systematic studies on the effects of the structural type of clay minerals added. This study was conducted to investigate the effects of structural type of clay minerals on physical properties of soils. Two experimental soils, layer-dominant and granule-dominant ones, were mixed with either a layer-type smectite or a granule-type zeolite at a level of 2.0 wt%. It was observed that water permeability of soils was decreased by smectite whereas not significantly changed by zeolite. This effect was much greater in layered clay-dominant soil than in granular clay-dominant soil. Our results clearly indicated that the relationship of structural type between a soil and an amendment plays a decisive role in the soil properties. Therefore, it is highly recommended that the structural types of both soil and amendment be taken into consideration for soil amendment by clay minerals.