• Analytical Science and Technology
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• v.37 no.5
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• pp.295-305
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• 2024

5-Hydroxymethyl-2-furaldehyde (5-HMF) is considered one of the main quality indexes of various food products. Its metabolism in humans can potentially lead to carcinogenic compounds. Metallic ions such as Zn, Mg, Mn, and Fe have been reported to enhance 5-HMF formation. Recently, studies on adsorbents that can extract specific organic and inorganic substances with one adsorbent have been conducted. However, simultaneous analysis of organic and inorganic materials typically requires distinct pre-treatment and analytical methods, which increase a lot of labor and cost. In this study, hybrid imprinted polymer (HIP) by mixing 5-HMF imprinted polymer (FIP) and zinc ion imprinted polymer (ZIIP) were generated to extract two analytes, Zn ion and 5-HMF, simultaneously. Physicochemical characterization of HIP was conducted by Fourier-transform infrared spectroscopy, scanning electron microscopy, and sorption tests. Extraction conditions including adsorbent mixing ratio, adsorbate mixing range, and equilibrium time were optimized. Freundlich adsorption model was as the best-fitting isotherm model to elucidate the adsorption mechanism. Affinity of Zn ion and 5-HMF on HIP was superior to non-HIP. In conclusion, HIP showed reasonable feasibility that could be used as an adsorbent to be used for simultaneous extraction of organic and inorganic compounds present in the sample.

• Analytical Science and Technology
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• v.5 no.4
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• pp.401-408
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• 1992

The ion-selectrodes based on calcium ferrite were prepared by mixing calcium oxide with ferric oxide on molar ratio of 0.6:1.4, 0.8:1.2, 1.0:1.0, respectively. The specimens were sintered at $1400^{\circ}C$ for 2hrs in $O_2$ and for 20min in $H_2$ atmosphere. The selectrode sintered in hydrogen atmosphere showed better responded potential and wider range of responded concentration than selectrode sintered in oxygen atmosphere. The ion-selectrodes base on calcium ferrite(0.6:1.4 molar ratio.) showed the highest potential to bivalent cations such as $Ca^{2+}$, $Ba^{2+}$, $Mg^{2+}$, $Zn^{2+}$ and halogen anions such as $I^-$, $Br^-$ in the range of $10^{-1}{\sim}10^{-7}M$. It showed good agreement with theoretical nernstian values.

• Journal of Surface Science and Engineering
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• v.41 no.3
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• pp.121-128
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• 2008

High strength 7xxx aluminum alloys have been applied to automotive bump back beam of the some limited model for light weight vehicle. The aluminum bump back beam is manufactured through extrusion, bending and welding. The residual stress given on these processes combines with the corrosive atmosphere on the road spreaded with corrosive chemicals to melt snow to occur the stress corrosion cracking. The composition of commercial 7xxx aluminum has Zn/Mg ratio about 3 and Cu over 2 wt% for better strength and stress corrosion cracking resistivity. But this composition isn't adequate for appling to the automotive bump back beam with high resistance to extrusion and bad weldability. In this study the composition of 7xxx aluminum alloy was modified to high Zn/Mg ratio and low Cu content for better extrusion and weldability. To estimate the resistivity against stress corrosion cracking of this aluminum alloy by slow strain rate test, the corrosion atmosphere and strain rate separate the stress corrosion cracking from conventional corrosion must be investigated. Using 0.6 Mol NaCl solution on slow strain rate test the stress corrosion cracking induced fracture was not observed. By adding 0.3% $H_2O_2$ and 0.6M $Na_2SO_4$ to 1M NaCl solution, the corrosion potential and current density of polarization curve moved to active potential and larger current density, and on the slow strain rate test the fracture energy in solution was lower than that in pre-exposure. These mean the stress corrosion cracking induced fracture can be estimated in this 1M NaCl + 0.3% $H_2O_2$ + 0.6M $Na_2SO_4$ solution. When the strain rate was below $2{\times}10^{-6}$, the stress corrosion cracking induced fracture start to be observed.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1072-1080
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• 2005

The extraction characteristics of heavy metals(HM) from a contaminated soil at existing lead smelters were investigated with ethylene diamine tetraacetic acid(EDTA), citrate and HCl as washing solutions. EDTA was more effective for Pb than for other heavy metals. As the mol ratio of EDTA/HM increased, the removal efficiency of heavy metals became higher. When the mol ratio of EDTA/HM approached to 6.5, it removed Pb most effectively. Citrate was effective especially in extracting Zn. The removal efficiency of HCl was comparatively high in almost all heavy metals, and at 0.3N concentration it was the highest. After soil washing process by the use of EDTA, the great part of exchangeable fractions and most of heavy metals of weakly adsorbed like carbonate fraction were extracted. For washing with citrate and HCl, four heavy metals showed the similar exchange of chemical partitioning and the exchangeable fractions of Pb which has weakly adsorbed to soil were more increased than before the process. As removal efficiency of citrate washing process depends upon the distribution of non-detrital fractions, so it can be contended that only the amount of non-detrital fractions could be removed from all the heavy metal content. EDTA and HCl could remove most of non-residual fractions in all heavy metals except Zn. As a result of EDTA washing, toxicity characteristic leaching procedure(TCLP) concentration of the processed soil met the USEPA Pb limit of 5.0 mg/L.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.574-580
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• 1994

The effect of dietary zinc(Zn) levels on cadmium (Cd)-induced hepatotoxicity was studied in serum and liver of rats. Adult male Spraque-Dawley rats were fed on diets containing one of three levels of zinc carbonate(0, 56, $560\mu\textrm{g}/kg$ diet) and Cd-treated groups were administrated oral intubation with cadmium chloride 95.0 mg/kg of body weight) at the sametime once a week. Net weight gain (NWG), feed intake (FI) and feed effciiency ratio (FER) in Zn deficiency groups significantly decreased as compared to that of control and excessive groups. Cd oral intubation caused a decrease in NWG and FI but an increase in Zn deficiency group in FER. GSH-Px, GST and catalase activity showed significant decrease in Zn deficiency and Zn excessive group. LPO content in liver significantly increased in Zn deficiency group. Cd oral intubation increased the content of LPO in Zn deficiency group as compared to control. GSH content and GST activity of hepatic tissue significantly decreased in Zn deficiency and excessive group. The activity of AST and ALT in serum were markedly increased in Zn deficiency, Zn excessive and Cd-treated groups. LDH and ALP activities significantly increased in Cd-treated group while ALP activity decreased by Zn deficiency. It was observed that the livers of rats exposed to Cd and Zn excessive group showed a marked increase of hepatic enzyme as compare to only Cd-treated in rats.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.215-232
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• 2020

The study area of Nokjeonri in Yeongwol belongs to the Taebaeksan Mineralized District. Ca and Mg skarn and related ore mineralization are developed in the Pungchon formation along the contact with the Imog granite. Ca skarn hosted in limestone mostly comprises garnet and pyroxene. Mg skarn developed in dolomite includes olivine and serpentine. Magnetite-hematite and pyrrhotite(±scheelite)-pyritegalena-sphalerite were mineralized during early and late stage, respectively. Garnet compositions are dominated by andradite series in proximal area and grossular series in distal area. Pyroxene compositions correspond to diopside series in majority. These compositional changes indicate that the fluids varied from oxidizing condition to reducing condition due to increased reaction with carbonated wall rocks as the fluids moved from the granite to a distal place. Fe₂O₃ and MgO concentrations of magnetite are higher in Mg skarn than those in Ca skarn, while FeO shows opposite trend. The Zn/Fe ratio of sphalerite increases with distance from the Imog granite. The δ³⁴S values of sulfide minerals are similar to those of the Imog granite, indicating magmatic origin in ore sulfur. Mineralization was established in the order of skarn, oxide and sulfide minerals with decreasing temperature and oxygen fugacity and increasing sulfur fugacity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.183-192
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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 $70\%$ for main element and $10\%$ for other 3 elements, respectively. 1. The contents of N-compounds in forages tended to be in inverse proportion to the yields. In the Mn/Zn trial, the 0/l00 to white clover resulted in the relatively high contents of soluble N-compounds and low ratio of pure protein/soluble N-compounds in company with a severe yield decrease. 2. In the Fe+Cu/Mn+Zn trial, the 0/100 and 100/0 resulted in the somewhat high contents of N-compounds in white clover. It was likely to be caused by the concentration effect derived from yield decrease. In addition, the 100/0 resulted in the relatively high content of soluble N-compounds and low ratio of pure protein/soluble N-compounds. The protein synthesis in white clover was likely to be negatively influenced by the 100/0. 3. In the Fe/Mn/Cu/Zn trial, white clover showed the low contents of crude and pure protein at the 1st cut. It was likely to be caused by the unbalanced mutual ratios derived from the high application levels of each single element. 4. In white clover at the 5th cut, the 0/100 of Mn/Zn and 100/0 of Fe+Cu/Mn+Zn resulted in the relatively high content of K. It was likely to be caused by the concentration effect derived from yield decrease.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.123-126
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• 2010

The purpose of present study was to analyze mineral contents in various tissues and investigate theirs relation with bone mineral density (BMD) in rats. Fifteen Sprague-Dawley rats were fed standard diet for 4 weeks. Body weight gain, feed intake, and feed efficiency ratio were 41.00 g/week, 171.15 g/week, and 0.24 respectively. Among 12 minerals in serum, Ca is the highest with 6.86 mg/dl. Serum Mg, Se, and Cu were 2.52 mg/dl, 0.23 mg/dl and 0.22 mg/dl respectively. Mg contents in liver, spleen, and kidney were $246.36\;{\mu}/g$, $105.01\;{\mu}/g$, and $273.38\;{\mu}/g$ respectively. Tibia contents of Ca, Mg, Zn, Fe and V were 194.91 mg/g, 23.10 mg/g, 0.60 mg/g, 0.35 mg/g and 0.14 mg/g respectively. BMDs of right tibia and spine were 122.04 mg/cm and $153.61\;mg/cm^2$. There were significantly positive correlations between tibia BMD and Se (p<0.05), tibia BMD and V (p<0.01), spinal BMD and V(p<0.05), respectively. It's expected that these results are used as a reference data in following study to elucidate physiological function of minerals.

• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.1-7
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• 1997

This study was performed to find out the mineral cycles of manganese and zinc in dynamic grassland ecosystems in a steady state condition at the northwest side on Mt. Kwanak. The experimental results may be summarized on the communities of a Zoysia japonica and a Miscanthus sincnsis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, manganese and zinc was greater quantity in a Miscanthus sincnsis than in a Zoysia japonica on Mt. Kwana For the case of steady procluction and release, the ratio of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants of Mn and Zn of the litter were 0.19 and 0. 14 in the Zoysia japon- ica grassland, and were 0.44 and 0.41 in a Miscanthus sincnsis grassland, respectively. The halftimes of Mn and Zn required for the release or accumulation of the litter on the grassland were 3. 65 and 4.95 years in the Zoysia japonica, and were 1.57 and 1.69 years in the Miscanthus sincnsis, respectively. The amounts of annual cycles for Mn and Zn in the grassland ecosystem under the steady-state conditions were 58.60 and 21.46 mg /$m^2$ in a Zoysia japonica, and were 372.12 and 321.49 ing /m$^2$ in a Miscanthus sincnsis grassland. Key words: Zoysia japonica. Miscanthus sincnsis, Mt. Kwanak, Manganese, Zinc, Mineral cycles.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.3
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• pp.403-409
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• 2018

Objective: The present study was conducted to investigate the effects of a lipid-coated zinc oxide (ZnO) supplement Shield Zn (SZ) at the sub-pharmacological concentration on intestinal morphology and gene expression in weanling pigs, with an aim to gain insights into the mechanism of actions for SZ. Methods: Forty 22-day-old weanling pigs were fed a nursery diet supplemented with 100 or 2,500 mg Zn/kg with uncoated ZnO (negative control [NC] or positive control [PC], respectively), 100, 200, or 400 mg Zn/kg with SZ for 14 days and their intestinal tissues were taken for histological and molecular biological examinations. The villus height (VH) and crypt depth (CD) of the intestinal mucosa were measured microscopically following preparation of the tissue specimen; expression of the genes associated with growth and immune function was determined using the real-time quantitative polymerase chain reaction. Results: There was no difference in daily gain, gain:feed, and diarrhea score between the SZ group and either of NC and PC. The VH and VH:CD ratio were less for the SZ group vs NC in the jejunum and duodenum, respectively (p<0.05). The jejunal mucosal mRNA levels of insulin-like growth factor (IGF-I) and interleukin (IL)-10 regressed and tended to regress (p = 0.053) on the SZ concentration with a positive coefficient, respectively, whereas the IL-6 mRNA level regressed on the SZ concentration with a negative coefficient. The mRNA levels of IGF-I, zonula occludens protein-1, tumor necrosis $factor-{\alpha}$, IL-6, and IL-10 did not differ between the SZ group and either of NC and PC; the occludin and transforming growth $factor-{\beta}1$ mRNA levels were lower for the SZ group than for PC. Conclusion: The present results are interpreted to suggest that dietary ZnO provided by SZ may play a role in intestinal mucosal growth and immune function by modulating the expression of IGF-I, IL-6, and IL-10 genes.