• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1042-1045
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• 1994

A thin film of silver ferricyanide (Ag$_3$Fe(CN)$_6$) on a platinum or gold substrates can be reduced electrochemically to the salt of silver ferrocyanide in potassium nitrate solution. The color of these films are orange and these films are shown to be electrochromic. The voltammogram is shown the asymmetry of the oxidation compared to the reduction wave under various supporting electrolytes. The standard heterogeneous electron-transfer rate for these films and bare Pt electrode were 0.49 ${\times}$ l0$^{-2}$ and 1.30 ${\times}$ l0$^{-2}$ cm/s, respectively, obtained using a rotating disc electrode. Rough D$_0$ values, evaluated from the Levich equation, for Fe(CN)$_6^{3-/4-}$ at both SF thin film and a bare Pt disc electrode were shown as 1.2l ${\times}$ l0-6 and 0.94 ${\times}$ l0$^{-6}$ cm$^2$/s, respectively. The conductivities, as determined from the slops of the i-V curves for a ca. 1 mm sample for dried SF potassium rich and deficient bulk samples pressed between graphite electrodes, were 9.34 ${\times}$ l0$^{-9}$ and 5.80 ${\times}$ l0$^{-9}$ (${\Omega}$${\cdot}$cm)$^{-1}$, respectively.

• 대한수의학회지
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• 제39권4호
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• pp.679-688
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• 1999

The combined effects of iron and selenium status on glutathione peroxidase (GSHPx) activity, cytochrome P-450 activity, and lipid peroxidation in the liver and intestinal mucosa of rats were investigated. In experiment one, four experimental groups (+Se+Fe, -Se+Fe, +Se++Fe, -Se++Fe) were manipulated for 3 weeks with intramuscular administration of irondextran (++Fe) and/or normal diet (+Fe) and deionized water (-Se) and/or selenium-supplemented deionized water (+Se). In experiment two, 2% dietary carbonyl iron (instead of the parenteral administration) was fed for 3 weeks to rats. Body weight of rats was significantly decreased in both parenterally and orally iron-overloaded groups (p<0.01), regardless of Se supplement. Serum iron was significantly increased in parenterally iron-overloaded groups but it was marginally increased in orally iron-overloaded groups. There was no significant difference in hemoglobin content among experimental groups in either experiment one or two. Total iron in the small intestine, intestinal mucosa, and livers was significantly high in both parenterally and orally iron-overloaded rats, regardless of selenium status. In the liver and intestine, GSHPx activity was significantly higher in all selenium-supplemented groups, compared to Se-deficient groups (p<0.01) and lipid peroxidation was significantly enhanced in both parenterally and orally iron-overloaded groups, compared to iron-adequate groups. There was no significant difference in cytochrome P-450 activity in the livers between groups in both experiment one and two. These results indicated that GSHPx activity in liver and intestinal mucosa was depended on selenium status, regardless of iron status, and iron-overload enhances lipid peroxidation in liver and intestinal mucosa by increasing the tissue iron content.

• Asian-Australasian Journal of Animal Sciences
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• 제19권8호
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• pp.1139-1147
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• 2006

This study was conducted to evaluate the trace elemental nutritive values of soil and forages collected from southwestern part of the province of Punjab, Pakistan. Soil and forage samples were collected fortnightly for two seasons. The concentrations of some trace minerals varied greatly among seasons and sampling periods. Seasonal effects were found in all soil micro-minerals except zinc, while forage iron, zinc, and selenium were affected by seasonal changes. Sampling periods effects were observed in all soil minerals and in forage copper, iron, zinc, and manganese only. All soil mineral levels except cobalt and selenium were sufficiently high to meet the requirements of plants for normal growth during both seasons. In contrast, soil Co and Se levels were severely deficient during both seasons and considered inadequate for plant growth. Soil Fe, Zn, Co, and Se levels were higher, and Cu and Mn lower during winter than those during summer. Forage Zn levels during summer were at marginal deficient levels, and in contrast, all other forage micro-minerals were within the required range for ruminants during both seasons. Although forage mico-minerals were within the range required by the ruminants, they were not sufficiently high to prevent the predisposition to various diseases caused by nutrient deficiency. Consequently, grazing animals at this location need continued mineral supplementation of these elements with a mixtures of high bio-availability rather than of high micro-mineral contents to support optimum ruminant productivity.

• 한국식품영양과학회지
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• 제28권3호
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• pp.705-709
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• 1999

To evaluate iron bioavailability in iron fortified milk, in vitro and in vivo method were used. Low molecular weight components(ILC) from milk was isolated and iron was added, then soluble iron from ILC iron complex was determined. Each iron sources and extrinsically labelled with FeCl3 was used for measuring absorption rate of iron from ILC radiolabelled iron complexes as radioiron absorption into the blood one hour after injection into ligated duodenal loops of iron deficient rats. Iron absorption rate was in the order of ferrous lactate(25.56%)$\geq$ferric citrate(24.71%)$\geq$ferrous sulfate(19.67%) when 100ppm iron was used. In separate experiments, iron fortified milks with each iron sources were gavaged into iron deficient rats. When 25ppm iron was added to milk, the order of iron absorption was ferrous sulfate(12.52%)>ferrous lactate(8.07%)>ferric citrate(6.52%) (p<0.05). When 100ppm iron was added to milk, absorption rate was decreased compared to the treatments with added 25ppm of iron. Absorption rate of ferrous sulfate(5.34%) from milk added 100ppm iron was highly lowered, but ferric citrate(6.45%) was not significantly changed. The absorption rate of ferrous lactate(5.82%) was 70% of 25ppm iron added milk.

• Journal of Animal Science and Technology
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• 제58권12호
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• pp.42.1-42.8
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• 2016

Background: Deficiency of macro and micro-minerals in the ration of dairy cows adversely affects growth, milk production and reproduction efficiency. It is essential to examine mineral concentrations in feeds offered to dairy cows in practical farms. Methods: Two villages from each taluka were selected at random for taking representative samples of feeds, forages and hair. Within the village, help was sought from village milk producers and district animal husbandry officer for identification of 4 to 5 farmers and collection of representative samples. All the samples were processed and analyzed for chemical composition as well as major macro and micro-minerals, using Inductively Coupled Plasma-Optical Emission Spectrometer. Results: Ca content in wheat straw (0.29%), crushed maize (0.02%) and wheat bran (0.12%) was found to be below the critical level (0.30%). The P content in concentrate ingredients was high (0.26-0.96%), but low in dry roughages (0.06-0.12%). Cereal straws (0.14%) and grains (0.12%) were deficient in Mg. Feeds and forages were found to be adequate in K (1.50%). Cereals straws were found to be deficient in S (0.11%). Greens were good source of Cu (12.02 ppm). Wheat straw was found to be low in Zn (18 ppm), but high in Mn (225 ppm) and Fe (509 ppm). Local grasses and azolla green were found to be rich source of Co (>1.00 ppm). Se (0.63 ppm) was present in appreciable quantities in most of the feedstuffs. Conclusions: From the present study, it was apparent that the feeds and forages available in the state of Jharkhand may not meet the requirements for Ca, P, Mg, Cu, Zn and Co in order to sustain a milk production of ~10 kg/day. Therefore, it is necessary to supplement these deficient minerals through area specific mineral mixture in the ration of dairy cows for improving productivity and reproduction efficiency.

• Structural Engineering and Mechanics
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• 제67권2호
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• pp.207-217
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• 2018

In past years, numerous problems have vexed engineers with regard to buckling, corrosion, bending, and overloading in damaged steel structures. This article sets out to investigate the possible effects of carbon fiber reinforced polymer (CFRP) and steel plates for retrofitting deficient steel square hollow section (SHS) columns. The effects of axial loading, stiffness, axial displacement, the position and shape of deficient region on the length of steel SHS columns, and slenderness ratio are examined through a detailed parametric study. A total of 14 specimens was tested for failure under axial compression in a laboratory and simulated using finite element (FE) analysis based on a numerical approach. The results indicate that the application of CFRP sheets and steel plates also caused a reduction in stress in the damaged region and prevented or retarded local deformation around the deficiency. The findings showed that a deficiency leads to reduced load-carrying capacity of steel SHS columns and the retrofitting method is responsible for the increase in the load-bearing capacity of the steel columns. Finally, this research showed that the CFRP performed better than steel plates in compensating the axial force caused by the cross-section reduction due to the problems associated with the use of steel plates, such as in welding, increased weight, thermal stress around the welding location, and the possibility of creating another deficiency by welding.

• Computers and Concrete
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• 제8권2호
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• pp.193-206
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• 2011

The use of Carbon Fiber Reinforced Polymers (CFRP) to strengthen reinforced concrete beams under bending and shear has gained rapid growth in recent years. The performance of shear strengthened beams with externally bonded CFRP laminate or fabric strips is raising many concerns when the beam is loaded under cyclic loading. Such concerns warrant experimental, analytical and numerical investigation of such beams under cyclic loading. To date, limited investigations have been carried out to address this concern. This paper presents a numerical investigation by developing a nonlinear finite element (FE) model to study the response of a cantilever reinforced concrete T-beam strengthened in shear with side bonded CFRP fabric strips and subjected to cyclic loading. A detailed 3D nonlinear finite element model that takes into account the orthotropic nature of the polymer's fibers is developed. In order to simulate the bond between the CFRP sheets and concrete, a layer having the material properties of the adhesive epoxy resin is introduced in the model as an interface between the CFRP sheets and concrete surface. Appropriate numerical modeling strategies were used and the response envelope and the load-displacement hysteresis loops of the FE model were compared with the experimental response at all stages of the cyclic loading. It is observed that the responses of the FE beam model are in good agreement with those of the experimental test. A parametric study was conducted using the validated FE model to investigate the effect of spacing between CFRP sheets, number of CFRP layers, and fiber orientation on the overall performance of the T-beam. It is concluded that successful FE modeling provides a practical and economical tool to investigate the behavior of such strengthened beams when subjected to cyclic loading.

• Asian-Australasian Journal of Animal Sciences
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• 제3권1호
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• pp.15-20
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• 1990

The nutritional status of trace minerals in cattle of Java in Indonesia was investigated by evaluating Cu, Fe, Mo, Zn and Mn concentrations in diets and livers, and Cu and Zn concentrations in blood plasma. Investigations were conducted on Jonggol (West Java), Malang (East Java) and Mojokerto (East Java) in both the rainy and the dry seasons in 1988. In Jonggol, low Cu concentrations in diets showing 7.1 mg/kg in the rainy season and 10.9 mg/kg in the dry season were observed and all plasma samples showed Cu concentrations below the critical level ($0.65{\mu}g/ml$). Thirty percent of the liver samples in Malang and 54% of those in Mojokerto showed lower Cu concentrations than the critical level (75 mg/kg on a dry matter basis). Fe concentrations in diets from the three regions showed a wide variation of values ranging from 249 to 30,000 mg/kg. A large amount of Fe was accumulated in livers from Malang and Mojokerto, giving average concentrations of 498 mg/kg. Zn concentration in diet and plasma samples were close to the borderline and some Zn concentration in these samples showed deficient levels. Mo and Mn concentrations in diets and livers showed normal levels.

• 한국식품영양과학회지
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• 제24권6호
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• pp.848-858
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• 1995

본 연구는 만성적인 에탄올 급여에 의한 조직내 항산화 영양소 함량의 변화에 대하여 비타민 A의 형태별 급여효과를 조사하고자 실시되었다. 실험동물은 Sprague-Dawley종 숫컷 흰쥐를 사용하였으며 에탄올 공급과 동시에 비타민 A 결핍군(FE), ${\beta}-carotene$ 섭취군(${\beta}E$), retinyl acetate 섭취군(RE) 그리고 13-cis-retinoic acid 성취군(RAE)과 에탄올 대신 동일 열량을 sucrose으로 공급 시킨 각각의 pair-fed군 등 모두 8군으로 나누어 7주 동안실섬 식이를 공급하였다. 항산화 영양소로 비타민 E, C, glutathione 그리고 무기질 함량의 분석을 통해서 에탄올에 의해 변화되는 생체내 항산화 영양소 상태와 이에 비타민 A의 형태별 급여 효과를 조사하여 다음과 같은 결과를 얻었다. 혈장내 ${\alpha}-tocopherol$ 함량은 에탄올­ 급여로 감소되었으나 간 조직내에서는 ${\beta}-carotene$ 섭취군만이 낮은 함량을 보였다. 그러나 간 조직내 tocopheryl acetate 함량은 pair-fed군에 비해서 에탄올 급여로 현저히 저하되었다. 혈장과 간 조직내에서 에탄올 급여에 의한 비타민 E 함량 감소는 retinyl acetate 공급으로 그 감소 정도가 가장 저하되었다. 혈장내 총 비타민 C 함량은 에탄올 급여와 동시에 ${\beta}-carotene$이나 retinyl acetate 섭 취군이 pair-fed군에 비해서 낮았으며 환원형과 산화형 비타민 C 함량비는 에탄올 급여로 낮았으나 ${\beta}-carotene$ 섭취시킨 군만이 높게 나타났다. 간 조직내 총 비타민 C 함량은 13-cis-retinoic acid 섭취군을 제외한 전 군에서 에탄올 급여로 증가하였으여 환원형과 산화형 비타민 C 비는 에탄올 급여군 중 ${\beta}-carotene$을 섭취시켰을 때 가장 높았다. 간 조직내 총 glutathion 함량은 에탄올 공급군과 pair-fed군 사이에 유의적인 차이를 보이지 않았으나 환원형과 산화형의 함량비에서는 에탄올과동시에 retinyl acetate나 13-cis-retinoic acid 섭취군에서 pair-fed군에 비해 높았다. 혈장내 Zn, Cu, Se, Fe 함량은 에탄올 급여군과 pair-fed군 사이에 일정한 경향을 보이지 않았으나 간 조직내 Zn, Cu 함량은 에탄올 급여로 감소된 반면 Fe 함량은 증가되었다. 이러한 결과들로 보아 에탄올은 체내 항산화 영양소 상태의 변화를 초래하며 비타민 A의 공급여부 뿐만 아니라 형태별 섭취에 의해서 항산화 영양소 상태가 변화될 수 있는 것으로 나타났다. 그러나 생체내 항산화 영양소들은 서로 상쇄, 상승 혹은 길항작용을 통해서 상호영향을 미치므로 각각의 항산화 영양소 상태 변화에 대한 정확한 기전 규명을 위해서는 다각적인 연구가 요구된다고 볼 수 있다. 그러나 지질과산화물의 함량과 체내 항산화 영양소 상태는 상호관련성이 있었으며 본 실험에서 에탄올 공급에 의한 항산화 영양소 함량의 감소는 대체로 비타민 A를 retinyl acetate 형태로 섭취시켰을 때 다소 경감되는 것으로 나타났다.

• Journal of Preventive Medicine and Public Health
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• 제37권4호
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• pp.329-336
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• 2004

Objectives : Iron (Fe) is an essential element in biological processes; however excessive Fe is harmful to human health. Some air pollutants contain a high level of Fe, and the human lung could therefore be over-exposed to Fe through inhaled air pollutants. This study was performed to investigate the role of metal transporters (divalent metal transporter 1, DMT1, and metal transporter protein 1, MTP1) in the lung under the environments of Fe deficiency in the body and Fe over-exposure in the lung. Methods : Rats were fed Fe deficient (FeD, 2-6 mg Fe/kg) or Fe supplemented (FeS, 120 mg Fe/kg) diet for 4 weeks, followed by a single intratracheal instillation of ferrous sulfate at low (10 mg/kg) or high (20 mg/kg) dose. Fe concentration was analyzed in the serum, lung and liver, and histopathological findings were observed in the lung at 24 hours after Fe administration. The level of DMT1 and MTP1 expression in the lung was analyzed by RT-PCR. Also, the effect of Fe deficiency in the body was evaluated on the level of Fe concentration and metal transporters compared to FeS-diet fed rats at the end of 4-week FeD or FeS diet. Results : The 4-week FeD diet in rats induced an Fe deficiency anemia with decreased serum total Fe, increased unsaturated Fe binding capacity and hypochromic microcytic red blood cells. The concentration of Fe in the lung and liver was lower in the FeD-diet fed rats than in the FeS-diet fed rats. The level of metal transporters mRNA expression was higher in the FeD-diet fed rats than in the FeS-diet. The concentration of Fe in the lung was increased in a dose-dependent pattern after intratracheal instillation of Fe into the rats, while the level of Fe in the serum and liver was not increased in the low-dose Fe administered rats. Therefore, DMT1 and MTP1 mRNA was highly expressed in both FeD-diet and FeS-diet fed rats, after intratracheal instillation of Fe. Conclusions : DMT1 and MTP1 mRNA were more highly expressed in FeD-diet fed rats than in FeS-diet fed rats. The over-exposure of Fe intratracheally induced high expression of metal transporters and increased Fe deposition in the lung in both FeD-diet and FeS-diet fed rats, but did not increase the Fe level of the serum and liver in low-dose Fe administered rats. These results suggest that the role of metal transporters in the lung might be different in a part from the duodenum under the environment of over-exposure to Fe.