• Journal of Magnetics
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• v.16 no.3
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• pp.271-275
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• 2011

This paper proposes a magnetoelectric (ME) composite transducer structure consisting of a magnetostrictive H-type Fe-Ni fork substrate and piezoelectric PZT plates. The fork composite structure has a higher ME voltage coefficient compared to other ME composite structures due to the higher quality (Q) factor. The ME sensitivity of the fork structure reaches 12 V/Oe (i.e., 150 V/cm Oe). The fork composite with two PZT plates electrically connected in series exhibits over 5 times higher ME voltage coefficient than the output of the rectangle structure in the same size. The experiment shows the composite of a Fe-Ni fork substrate and PZT plates has a significantly enhanced ME voltage coefficient and a higher ME sensitivity relative to the prior sandwiched composite laminates. By the use of a lock-in amplifier with 10 nV resolution, this transducer can detect a weak magnetic field of less than $10^{-12}$ T. This transducer can also be designed for a magnetoelectric energy harvester due to its passive high-efficiency ME energy conversion.

• Journal of Nutrition and Health
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• v.32 no.8
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• pp.855-863
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• 1999

This study was performed to investigate the effect of dietary protein level throughout gestation and lactation on milk composition and on postnatal growth in infants, using rats as an animal model. Female Sprague-Dawley rats were provided with either high(25% ISP(Isolated Soy Protein)diet) or low protein diet(10% ISP diet) throughout gestation and lactation. Milk samples were taken for analysis from the lactating rats at days of 7, 14, 21, of lactation. Dams and some pups were killed after 4 weeks from parturtion (Experiment 1). Pups from dams of each diet groups were randomly selected and reared with 25% or 10% ISP diet for 4 more weeks (Experiment 2). In experiment 1, maternal protein intake and body weight gain throughout gestation and lactation was higher in 25% ISP group. Serum protein, Ca, Fe, Zn, K concentrations were significantly higher in 25% ISP group. There was no difference in birth weight between two groups, however the mean body weight at 4 weeks postpartum were significantly higher in 25% ISP group. Serum profiles of pups at weaning were similar to that of dams. Milk compositions were changed during lactation processes and were affected by dietary protein level. Lactose and Ca, Cu, Fe concentrations in milk were higher in 25% ISP group, whereas, lipid, triglyceride were higher in 10% ISP group. In experiment 2, food intake was higher in milk were higher in 25% ISP group but was unaffected by pup's dietary protein level after weaning. The weights of liver and kidney were affected by maternal protein intake. The weight of intestine was affected by pup's dietary protein level after weaning. The weight of femur and scapula were affected by maternal protein intake. There were no differences between four groups in serum profiles. Therefore, as mentioned above, it seemed that the effect of maternal protein malnutrition to fetus was able to be overcome to some extent by high protein diet intake after weaning. In conclusion, 1) Dietary protein level throughout gestation and lactation affected both nutritional status of dams and pups and milk composition: 25% ISP groups supported better nutritional status than 10% ISP group 2) It seemed that effect of dietary protein level after weaning on pups was able to be overcome the influence of maternal diet in fetus to some extent.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.602-609
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• 1997

The seed formation and growth of $\alpha$-ferric oxyhydroxide with aerial oxidative precipitation from aqueous solution of ferrous sulfate with KOH, NaOH, $Na_2CO_3$ and $K_2CO_3$ as precipitants have been studied by free pH drift experiment. It has been shown that all precipitants give same particle formation and growth path, and average particle length from KOH and NaOH as precipitants was about 1.5 times shorter than that of $K_2CO_3$ and $Na_2CO_3$. When initial mole ratio, $R_o=[Fe^{2+}]_o/[OH^-]_o$ of KOH was decreased the particle was grown oxyhydroxide seed growth from aqueous solution of ferrous sulfate with KOH has been studied. The influence of the air flow rate, reaction temperature and initial mole ratio, $R_o=[Fe^{2+}]_o/[OH^-]_o$, on the kinetics of seed growth are investigated by static pH experiment. The oxidation rate of seed growth increased with increase in the air low rate, reaction temperature and initial mole patio. The activation energy of seed growth is 16.16 KJ/mol and the rate equation of seed growth can be written as follows: $-\frac{d[Fe^{2+}]}{dt}=1.46{\times}10^4[P_{o2}]^{0.66}[OH^-]^{2.19}exp(-\frac{16.16}{dt})$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2771-2778
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• 2009

This study was performed to solve the problem of the 2nd contamination and excessive treatment cost by determining proper quantity of hydrogen peroxide, iron catalyst, mixing method, and input mode that should be provided when Fenton oxidation (this is mostly applied to small contaminated areas such as service station sites) is applied to the excavated and diesel-contaminated soil. Soil artificially contaminated with 10000mg/kg of diesel was used for the experiment. In the batch test, diesel removal seemed to increase as the concentration of hydrogen peroxide increases. When iron catalyst was added, removal efficiency of diesel was much higher than the time when hydrogen peroxide was added solely. The removal efficiency showed greater when Fe(III) was added compared to Fe(II). Column experiment was executed on the basis of results of the batch test to investigate adequate reagent mixing and input methods. The highest efficiency was acquired in the case of separate input mode. Also, it was found that when inputting Fe(III) iron catalyst and separately inputting hydrogen peroxide after dividing the bundle in the column, removal efficiency was 92.8%, which was 9 times greater than that of the first method, 10.5%, when only hydrogen peroxide was added. Thus, it is expected that if the result of this research is applied to Fenton oxidation for the remediation of soil contaminated by diesel, the problem of the 2nd contamination and excessive treatment charge caused by excessive addition of hydrogen peroxide and iron catalyst could be solved.

• Journal of the Korean Magnetics Society
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• v.14 no.5
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• pp.192-195
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• 2004

Magnetic properties by exchange biased perpendicular magnetic anisotropy in [Pd(0.8 nm)/Co(0.8 nm)]$_{5}$/FeMn(15 nm) multilayers deposited by dc magnetron sputtering system are investigated. As inserted Pd layer of interface between [Pd/Co] multilayer and FeMn film, the Hex of perpendicular anisotropy was improved from 127 Oe to 145 Oe. But result of an experiment by thermal stability, the Hex of the case that an inserted layer was inserted in decreased from low 20$0^{\circ}C$ in about 5$0^{\circ}C$ more if not inserted. If Ta was a buffer layer, the experiment results along material of buffer layer, the H$_{ex}$ obtained the largest 127 Oe. And if Pd was a buffer layer, H$_{ex}$ obtained the largest 169 Oe. Also, the Hc in buffer layer of Ta and Pd obtained the largest 203 Oe and 453 Oe, respectively.

• Journal of Soil and Groundwater Environment
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• v.27 no.4
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• pp.49-62
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• 2022

The magnesium and iron-based layered double hydroxide (Mg-Fe LDH) was synthesized by the co-precipitation process and the bead type LDH (BLDH, 5~6 mm in diameter) was manufactured by using the Mg-Fe LDH and the starch as a binder. To evaluate the feasibility of the BLDH as the As stabilizer in the soil, various experiments were performed and the As stabilization efficiency of the BLDH was compared to that of powdered type LDH (PLDH, <149 ㎛ in diameter). For the As sorption batch experiment, the As sorption efficiency of both of the PLDH and the BLDH showed higher than 99%. For the stabilization experiment with soil, the As extraction reducing efficiency of the PLDH was higher than 87%, and for the BLDH, it was higher than 80%, suggesting that the BLDH has similar the feasibility of As stabilization for the contaminated soil, compared to the PLDH. From the continuous column experiments, when more than 7% BLDH was added into the soil, the As stabilization efficiency of the column maintained at over 91% for 7 pore volume flushing (simulating about 21 months of rainfall) and slowly decreased down to 64% after that time (to 36 months) under the non-equilibrium conditions. Results suggested that more than 7% of BLDH added in As-contaminated soil could be enough to stabilize As in soil for a long time. The main As fixation mechanisms on the LDH were also identified through the X-ray fluorescence (XRF), the X-ray diffraction (XRD), and the Fourier transform infrared (FT-IR) analyses. Results showed that the LDH has enough of an external surface adsorption capacity and an anion exchange capability at the interlayer spaces. Results of SEM/EDS and BET analyses also supported that the Mg-Fe LDH used in this study has sufficient porous structures and outer surfaces to fix the As. The reduction of carbonate (CO₃^2-) and sulfate (SO₄^2-) anions in the LDH after the reaction between As and the LDH was observed through the FT-IR, the XRF, and the XRD analyses, suggesting that the exchange of some of these anions with the arsenate (H₂AsO₄^- or HAsO₄^2-) occurs at the LDH interlayers during the stabilization process in soil.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.3
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• pp.38-46
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• 2023

In this study, a bearing test was performed and analytically evaluated to evaluate the bearing performance according to the application of the aluminum stiffener in round-end concrete. In the bearing strength test, the change in bearing performance due to the aluminum stiffener using the aluminum form for manufacturing concrete with round-end, and the steel anchor bolts for member movement and assembly was confirmed. The FE analysis model was identically configured to the experimental conditions, and the result was compared with the experiment. Also, the crack patterns and stress behavior were confirmed. In addition, the effect of strength change of the aluminum stiffener on the round-end concrete was also evaluated analytically. The bearing strength of the round-end concrete increased by about 20% due to the aluminum stiffener, and it was confirmed that the steel anchor bolt did not affect the bearing strength. The maximum load and crack patterns shown as a result of FE analysis were similar to those of the experiment. As a result of FE analysis according to the strength change of the aluminum stiffener, the maximum load change according to the increase and decrease of the strength of the aluminum stiffener by 10% and 20% was evaluated to have no significant effect at a maximum of about 4% compared to before the strength change.

• Analytical Science and Technology
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• v.21 no.4
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• pp.332-337
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• 2008

Purification of silica mineral was compared with various leaching methods such as shaking, stirring, ultrasonic with 2.5% HF/HCl solution. Among them, ultrasonic method showed a best leaching effect. From the leaching experiment, Na, K, Fe, Al exist as the major impurity elements. The removal rate of Al, Fe showed little difference with various leaching methods but Ca, Mn, Na were very different. Four kinds of silica mineral (>99% purity) after physical purification treatment were used for ultrasonic leaching experiment. Among them IN-Si had a highest impurity removal rate. Ca, Cr, K, Zn were removed above 80% using ultrasonic leaching method and Fe was also removed above 60%. But Al showed 10~60% removal rate with different samples.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.105-114
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• 2004

This pot experiment was. conducted to investigate the effects of systematic variation application of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover. The treatments of systematic variation were 0/100, 25/75, 50/50, 75/25, and 100/0％ in the Fe/Cu(trial-1), Mn/Zn(trial-2), and Fe + Cu/Mn + Zn(trial-3), respectively. The treatments of Fe/Mn/Cu/Zn(trial-4) were composed of 70％ in main element and 10％ in other 3 elements, respectively. 1. In general, the unbalanced applications of Fe and Mn resulted in the Mn and Fe deficiencies(chlorosis) on white clover, respectively, because of the antagonism between Fe and Mn. In white clover, the traits of growth, root/nodule, and flowering, which were influenced by the systematic variation of Fe, Mn, Cu, and Zn, were closely correlated to each other. In the Fe/Cu trial, the 0/100 and 25/75 induced a Fe-deficiency on white clover, and the 0/100 also showed poor root growth and flowering. In addition, the 50/50 and 75/25 showed an early flowering of white clover. 2. In the Mn/Zn trial, the 0/100 induced a severe Mn-deficiency(chlorosis) on white clover. The 25/75 and 50/50, however, diminished the chlorosis symptom. The 75/25 and 100/0 showed generally good root growth and flowering of white clover. 3. In the Fe + Cu/Mn + Zn trial, the 0/100 induced a Fe-deficiency, and the 100/0 induced a Mn-deficiency on white clover, which were correlated to the poor root growth and flowering. The 75/25 showed good root growth and flowering of white clover. 1be flowering of white clover tended to be more influenced by the Fe + Cu than by the Mn + Cu ratios. 4. In the Fe/Mn/Cu/Zn trial, the Fe and Mn deficiencies on white clover, which were influenced by the Mn and Fe treatments, also occurred. The Cu and Zn-deficiency symptoms, however, were not recognized. General differences have been showed in the numbers of flowers as following orders; Zn > Cu > Mn > Fe - 70% treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.281-292
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• 2004

This pot experiment was conducted to investigate the effects of systematic variation appling of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover, The treatments of systematic variation were 0/100. 25/75, 50/50. 75/25, and $100/0\%$ in the Fe/Cu, Mn/Zn, and Fe+Cu/Mn+Zn trials, respectively. The treatments of Fe/Mn/Cu/Zn trial were $70\%$ in main-element and $10\%$ in other 3sub-elements. 1 . General differences had been showed in the relative contents, uptake amounts, and mutual ratios of Fe, Mn, Cu, and Zn between orchardgrass and white clover. The effects of Fe application on the all traits were generally insignificant. The Mn and Cu applications, however, showed consistent differences in the all traits. At the high relative content of Mn in the forages influenced by the Mn application, the relative contents of Fe, Cu and Zn were greatly decreased without the significant differences in common content. 2. The increase of uptake amount of each micronutrient was not positively correspond to the yield increase. In some cases, the uptake amount of micronutrient was greatly increased without the significant increase of yield. At the Mn application, the Mn uptake amount was relatively much more increased than increase of the yield. The uptake amount of each element was significantly increased by the application with Mn and Cu. However, it was not in the case of Fe and Zn. 3. The mutual ratios of micronutrients were more influenced by the applications of Mn and Cu, especially Mn, than those by the applications of Fe and Zn. In the Fe/cu trial, the ratios of Fe/Cu showed 6.0~ 10.5 in orchardgrass and 10.2~ $16.4\%$ level of difference in white clover. In the Fe+Cu/Mn+Zn trial, the ratios of Mn/Cu, Mn/Zn, and Fe/Mn were greatly influenced by the treatments. It has been also found that the poor growth of white clover was caused by the unbalanced ratios of Fe/Mn, and it tended to be enhanced by the good applications and mutual ratios of other elements.