• Resources Recycling
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• v.12 no.4
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• pp.20-29
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• 2003

In order to efficiently recycle the waste solution resulting from shadow mask processing, nano-sized Ni-ferrite powder was fab-ricated through spray pyrolysis process. The average particle size of the powder was below 100nm. In this study, the effects of the reaction temperature. the concentration of raw material solution and the injection speed of solution on the properties of powder were respectively investigated. As the reaction temperature increased from $800^{\circ}C$ to $1100^{\circ}C$, average particle size of the powder significantly Increased and power structure became more solid, whereat its specific surface area was greatly reduced. Formation rate and crystallization of($NiFe_2$$O_4$) phale increased along with the temperature rise. As the concentrations of iron and nickel components in wastere solution increased, particle size of the powder became larger, particle size distribution became more irregular, and specific surface area was reduced. Formation rate and crystallization of $NiFe_2$$O_4$ phase increased significantly along with the increase of the concentration of solution. As the inlet speed of solution increased, particle size of the powder became larger, particle size distribution became wider, specific surface area was reduced and powder structure became less solid. As the inlet speed of solution decreased, formation rate and crystallization of $NiFe_2$$O_4$ phase significantly increased.

• Journal of the Korean Vacuum Society
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• v.19 no.5
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• pp.377-384
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• 2010

Many routes have been developed for the synthesis of signle-walled carbon nanotubes (SWCNTs). We spun fibers of SWCNTs directly from vertical furnace using a liquid source of carbon and an iron-contained molecule. The solution was prepared by ethanol as a carbon source, in which ferrocene as a catalyst, thiophene were dissolved. It was then injected from the top of the furnace into hot zone with hydrogen as a carrier gas. We successfully synthesized high-quality SWCNTs by adjusting the various experimental conditions, such as concentration of ferrocene, solution injection rate, concentration of thiophene, and hydrogen flow rate. Measurement of Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy were carried out to find the optimized conditions. The synthesized SWCNTs (1.16~1.64 nm) appeared a bundle structure and well-aligned parallel to the direction of furnace. These results also provide an simple way for high-quality SWCNTs mass production and fabricating direct spining SWCNTs fiber. It will allow one-step production of SWCNTs fiber with potentially excellent properties and wide-range applications.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.1-6
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• 1993

The activity change of mulberry seeds protease was compared during germination for 5 days at 28$^{\circ}C$ in the dark place after daily hormone injection of different concentration. The protease from germinated mulberry seeds for 4 days was partially purified and the enzyme characteristics was investigated. The protease activity of mulberry seeds treated by hormone was highest with 10 $\mu$m GA3 followed by 10 $\mu$M zeatin and 10 $\mu$M kinetin. The protease activity of mulberry seeds was increased by 14% with 10ml agar culture that control at 4th day of germination. The protease from mulberry seeds was purified 313 fold by DEAE-Toyo-pearl 650M, Butyl-Toyopearl, Hydrozylapatite and Toyopearl HW 55M. After purification, the specific activity of the enzyme was 175 units/mg. Optimum pH and temperature of protease from mulberry seeds was 5.0 and 37$^{\circ}C$, respectively. The protease was stable below 37$^{\circ}C$ and the enzyme activity was decreased by 50%, when incubated at 52$^{\circ}C$ for 10minutes. The protease activity of mulberry seeds was inhibited by metal ions such as mercury, iron, zinc, copper, but activited by magnesium, choromium, aluminium ions. The Km value of the protease was 0.89mM with azocasein as a subscribe.

• Animal Bioscience
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• v.35 no.10
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• pp.1616-1627
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• 2022

Objective: This work was conducted to investigate the effects of oxidative stress on meat quality, mitochondrial function, calcium metabolism and ferroptosis of broilers. Methods: In this study, a total of 144 one-day-old male Ross 308 chicks were divided into 3 groups (control group, saline group, and hydrogen peroxide [H₂O₂] group) with 6 replicates of 8 broilers each. The study lasted for 42 d. The broilers in the saline and H₂O₂ groups were intraperitoneally injected with 0.75% saline and 10.0% H₂O₂ on the 16th and 37th day of the experimental period respectively, the injection volumes were 1.0 mL/kg of broiler body weight. On the 42nd day of the experimental period, two chicks were randomly selected from each cage, a total of thirty-six chicks were stunned by electric shock and slaughtered to collect breast muscle samples. Results: The H₂O₂ exposure reduced pH value, increased drip loss and shear force of breast meat (p<0.05), impaired the ultrastructure and function of mitochondria. The H₂O₂ exposure damaged the antioxidant system in mitochondria, excessive reactive oxygen species carbonylation modified calcium channels on mitochondria, which impaired the activities of key enzymes on calcium channel, resulted in the increased calcium concentration in cytoplasm and mitochondria (p<0.05). In addition, the H₂O₂ exposure increased the iron content and lipid peroxidation (p<0.05), which induced ferroptosis. Conclusion: Oxidative stress could impair meat quality by causing mitochondrial dysfunction, resulting in calcium metabolism disorder and ferroptosis.

• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.31-40
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• 2010

Purpose : To compare the relative values of various fast breath-hold imaging sequences for superparamagnetic iron-oxide (SPIO)-enhanced hepatic MRI for the assessment of solid focal lesions with a 3T MRI unit. Materials and Methods : 102 consecutive patients with one or more solid malignant hepatic lesions were evaluated by spoiled gradient echo (GRE) sequences with three different echo times (2.4 msec [GRE_2.4], 5.8 msec [GRE_5.8], and 10 msec [GRE_10]) for $T2^*$-weighted imaging in addition to T2-weighted turbo spin echo (TSE) sequence following intravenous SPIO injection. Image qualities of the hepatic contour, vascular landmarks and artifacts were rated by two independent readers using a four-point scale. For quantitative analysis, contrast-to-noise ratio (CNR) was measured in 170 solid focal lesions larger than 1 cm (107 hepatocellular carcinomas, nine cholangiocarcinomas and 54 metastases). Results : GRE_5.8 showed the highest mean points for hepatic contour, vascular anatomy and imaging artifact presence among all of the subjected sequences (p<0.001) and was comparable (p=0.414) with GRE_10 with regard to lesion conspicuity. The mean CNRs were significantly higher (p<0.001) in the following order: GRE_10 ($24.4{\pm}14.5$), GRE_5.8 ($14.8{\pm}9.4$), TSE ($9.7{\pm}6.3$), and GRE_2.4 ($7.9{\pm}6.4$). The mean CNRs of CCCs and metastases were higher than those of HCCs for all imaging sequences (p<0.05). Conclusion : Regarding overall performances, GRE using a moderate echo time of 5.8 msec can provide the most reliable data among the various fast breath-hold SPIO-enhanced hepatic MRI sequences at 3T unit despite the lower CNR of GRE_5.8 compared to that of GRE_10.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.2
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• pp.111-123
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• 2022

Carbonate green rust (CGR) and sulfate green rust (SGR) commonly occur in nature. In this study, CGR and SGR were synthesized through co-precipitation, and their formation mechanisms and physicochemical properties were investigated. X-ray diffraction (XRD) and Rietveld refinement showed both CGR and SGR with layered double hydroxide structure were successfully synthesized without any secondary phases under each synthetic condition. Refined structural parameters (unit cell) for two green rusts were a (=b) = 3.17 Å and c = 22.52 Å for CGR and a (=b) = 5.50 Å and c = 10.97 Å for SGR with the crystallite size 57.8 nm in diameter from (003) reflection and 40.1 nm from (001) reflections, respectively. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) results showed that both CGR and SGR had typical hexagonal plate-like crystal morphologies but their chemical composition is different in the content of C and S. In addition, Fourier transform infrared (FT-IR) spectroscopy analysis revealed that carbonate (CO₃^2-) and sulfate (SO₄^2-) molecules were occupied as interlayer anions of CGR and SGR, respectively. These SEM/EDS and FT-IR results were in good agreement with XRD results. Changes in the solution chemistry (i.e., pH, Eh and residual iron concentrations (Fe(II):Fe(III)) of the mixed solution) were observed as a function of the injection time of hydroxyl ion (OH^-) into the iron solution. Three different stages were observed in the formation of both CGR and SGR; precursor, intermediator, and green rust in the formation of both CGR and SGR. This study provides co-precipitation methods for CGR and SGR in a way of the stable synthesis. In addition, our findings for the formation mechanisms of the two green rusts and their physicochemical properties will provide crucial information with researches and industrials in utilizing green rust.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.980-987
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• 2003

In this report, we investigated the detoxication effects of Saururus chinenis, Geranium nepalense, Lonicera japonica, Cassia obtusifolia, Glycyrrhiza uralensis, or their mixtures by employing acute toxicity tests for nicotine and dioxin. When fatal doses $(LD_{100}\;=\;42\;mg/kg)$ of nicotine were injected into the abdominal cavities of ICR mice, those treated with OHEM showed delayed paralysis, half the duration of hyperactivity, and a 73 % survival rate. The results revealed the strong detoxicating effects of the mixtures. We also measured the amount of the degradation product of nicotine and cotinine in humans. Consumption of OHEM promoted (he more specific) the metabolic pathways of nicotine, increasing continine excretion by 1.5 times. As a result the amount of cotinine in urine was reduced to less than 5% after treatment with OHEM. In order to test the toxicity of dioxin, we used TcnN(SD)BR rats exposed to TCDD. While TCDD treatment reduced the blood levels of hemoglobin and platelet, OHEM consumption relieved these effects and, furthermore, helped to recover the number of platelet to the normal level (p<0.05). Moreover, neutrophils (%) and monocytes (%), which were reduced by the injection of TCDD, recovered to normal levels upon treatment with OHEM. The amount albumin reduced by TCDD (p<0.05) normalized, while the activities of GOT and GTP increased by TCDD were reduced. Increases in total cholesterol and neutral fatty acids induced by TCDD were also reduced by OHEM injection (p<0.05). In the kidney, TCDD-induced rises in creatinine were suppressed by OHEM treatment, while decreases in iron levels from TCDD were raised to normal. The treatment of TCDD had more toxic effects in the blood and pancreas than on the liver, kidney and heart. On the other hand, the detoxication of OHEM had significant effects on the liver and pancreas. The normalization by OHEM of various clinical abnormalities induced by TCDD demonstrates the detoxicating effect of OHEM that ameliorates systemic metabolism not properly functioning.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.687-694
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• 2020

Two oxidizing agents (KMnO4, H2O2), and one neutralizing agent (NaOH) were applied to evaluate Mn removal in mine drainage. A Mn2+ solution and artificial mine drainage were prepared to identify the Fe2+ influence on Mn2+ removal. The initial concentrations of Mn2+ and Fe2+ were 0.1 mM and 1.0 mM, respectively. The injection amount of oxidizing and neutralizing agents were set to ratios of 0.1, 0.67, 1.0, and 2.0 with respect to the Mn2+ mole concentration. KMnO4 exhibited a higher removal efficiency of Mn2+ than did H2O2 and NaOH, where approximately 90% of Mn2+ was removed by KMnO4. A black MnO2 was precipitated that indicated the oxidation of Mn2+ to Mn4+ after an oxidizing agent was added. In addition, MnO2 (pyrolusite) is a stable precipitate under pH-Eh conditions in the solution. However, relatively low removal ratios (6%) of Mn2+ were observed in the artificial mine drainage that included 1.0 mM of Fe2+. The rapid oxidation tendency of Fe2+ as compared to that of Mn2+ was determined to be the main reason for the low removal ratios of Mn2+. The oxidation of Fe2+ showed a decrease of Fe concentration in solution after injection of the oxidizing and neutralizing agents. In addition, Mn7+ of KMnO4 was reduced to Mn2+ by Fe2+ oxidation. Thus, the concentrations of Mn increased in artificial mine drainage. These results revealed that the oxidation method is more effective than the neutralization method for Mn removal in solution. It should also be mentioned that to achieve the Mn removal in mine drainage, Fe2+ removal must be conducted prior to Mn2+ oxidation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.529-536
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• 2011

In this study, we confirmed that the SWRO(Sea Water Reverse Osmosis) production water has more hard corrosiveness than the tap water by fundamental experiment. According to the result, the target of this study was aimed at developing maintenance and anti-corrosion method. In the early stages of the research, batch tests using mild steel coupons and electrochemical experiments were applied to compare the corrosiveness between SWRO production water and the tap water. After then, two corrosion control methods for SWRO production water were applied. Liquid lime($Ca(OH)_2$) and Carbon Dioxide($CO_2$) were inserted and compared with the combination of liquid lime with phosphate corrosion inhibitor and carbon dioxide. The water qualities were evaluated through LSI(Langelier Saturation Index) and proper injection ratio was deduced by the result. Since then, simulated loop system test were performed to evaluate anti-corrosion effect depending on corrosion inhibitors. Subsequently, carbon steel pipes equipped at the loop system were detached for SEM, EDX and XRD analysis to acquire quantitative and qualitative data of the major corrosion products inside the pipes. In conclusion, the controled groups with anti-corrosion techniques applied were effective by appearing 97.4% and 90.9% of improvements in both case of liquid lime and the liquid lime with a phosphate corrosion Inhibitor. furthermore, major components of scale were iron oxides, on the other hand, protective effect of film formation by calcium carbonate($CaCO_3$) could be confirmed.

• Journal of Nutrition and Health
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• v.39 no.5
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• pp.433-443
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• 2006

The effects of Allium vegetables on blood glucose levels and lipid metabolism in streptozotocin (S12) induced diabetic rats were investigated. Diabetes mellitus was induced by S1'2 injection (45 mg/kg 5.w.) into the tail vein. Sprague-Dawley rats weighing $220\;{\pm}\;10\;g$ were randomly assigned to 7 groups: normal, S1'2-control and five Allium groups (Allium cepa, Allium fistulosum, Allium sativum, Allium tuberosum and Allium victorialisL Normal and S12control groups were fed an AIN-93 diet and five Allium groups were fed a modified diet containing. 10% Allium powder each for 4 weeks. Body weight, diet intake, food efficiency ratio (FER) and organ weights- were monitored. Activities of aspartate aminotransferase (AST) & alanine aminotransferase (ALT) were observed: Plasma lev~ls of glucose, free fatty acid, triglyceride and HDL-cholesterol were analyzed. Levels of glycogen, cholesterol and triglyceride in liver were determined. Levels of malondialdehyde (MDA) in liver, lung, kidney, and pancreas were assayed. The hepatic contents of chromium (Cr) , iron (Fe), zinc (Zn) and manganese (Mu) were measured. The Allium sativum group had weight gain and suppressed a hypertrophy of the kidney significantly. The activity of ALT was significantly lowered in the diabetic groups except Allium sativum group compared to STZ-control group. The Allium sativum and Allium tuberosum groups showed the hypoglycemic effects at 4 weeks. There were no significant differences between the control and all the other diabetic groups in the plasma levels of cholesterol, HDL-cholesterol, triglycerides and free fatty acids. Most of the Allium groups except Allium fistulosum were observed significantly lowered level of MDA in the lung compared to STZ-control group. The diabetic rats fed the Allium cepa and Allium sativum have shown significantly lowered hepatic Zn contents. The results suggested that the intake of the Allium vegetables may be effective in the antihyperglycemia by lowering blood glucose levels.