• Title/Summary/Keyword: Oxidization

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A Study on Removal of Organic Matter and Chromaticity from Urine Using Chemical Oxidization Process (화학적 산화공정을 이용하여 소변의 색도 및 유기물 처리를 통한 재이용 기술 연구)

  • Shin, Sung-Hoon;Jung, Jong-Tai;Cho, Yong-Chul
    • Journal of Korean Society of Water Science and Technology
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    • v.26 no.6
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    • pp.109-115
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    • 2018
  • This study was conducted to solve the water shortage problem by reclaiming urine from homes or public places and using it as cleaning water for toilets. The process used in this experiment is a chemical oxidation process combining ozone, hydrogen peroxide, and UV. We set the key substance that is to be removed as chromaticity and conducted the experiment to remove it. If the quantity or concentration of injected ozone, UV, and hydrogen peroxide is insufficient, then the chromaticity will initially increase due to low oxidizing power, and will later decrease. In addition, the efficiency of removing chromaticity appeared to be higher, depending on the quantity of ozone injected, for medium concentrated urine than highly concentrated urine. However, the absolute quantity of removed chromaticity was about 68% higher for highly concentrated urine, when 16 g/hr of ozone was injected. The higher the pH level, the reaction time and efficiency of removing chromaticity were higher, and in normal conditions, in reference to a pH of 8.55, there was a 6% difference in efficiency between a pH level of 5.05 and a pH level of 10.12. Finally, when processing urine through an ozone-only process, COD decreased steadily over time, but DOC did not decrease. This is because ozone reacts selectively with organic matter.

Electrochemical Synthesis of Metal-organic Framework (전기화학적 방법을 통한 금속 유기 골격체 합성)

  • Moon, Sanghyeon;Kim, Jiyoung;Choi, Hyun-Kuk;Kim, Moon-Gab;Lee, Young-Sei;Lee, Kiyoung
    • Applied Chemistry for Engineering
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    • v.32 no.3
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    • pp.229-236
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    • 2021
  • During the last two decades, metal-organic frameworks (MOFs) have been drawn attention due to their high specific surface area, porosity, and catalytic activities that allow to use in many applications such as sensor, catalysis, energy storage, etc. To synthesize MOFs hydrothermal or solvothermal method were generally used. However, these methods require high-cost equipment and long time-spend for the synthesis with multi-step process. In contrast, electrochemical synthesis has been considered as a simple and easy process under the ambient conditions. In this review, we described the mechanism of electrochemical MOFs synthesis by the number of configured electrodes system, with the recent reports of various applications.

Anti-Melanogenic Effect of Thymol, a Major Odorant in Essential Oils of Family Lamiaceae (꿀풀과 식물 정유의 주성분인 Thymol의 미백활성에 관한 연구)

  • Choi, Deok-Gyun;Park, Chan Ik;Lee, Sun-Mi;Baek, Jeong-In
    • The Korea Journal of Herbology
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    • v.34 no.4
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    • pp.19-25
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    • 2019
  • Objectives : Thymol (2-isopropyl-5-methylphenol), a natural monoterpenoid phenol, is one of the major odorant constituents found in natural essential oils of various herbal plants, such as Thymus quinquecostatus and Thymus vulgaris. Multiple biological activities of thymol, including antioxidative, antimicrobial, and anti-inflammatory effects, have been reported in numerous in vitro studies, and recently it was suggested that thymol may could inhibit oxidization of L-dihydroxyphenylalanine (L-DOPA) to dopaquinone required in melanogenesis pathway, as an antioxidant. Methods : MTT assay was performed to test the cytotoxic effect of thymol in B16F10 cells. Inhibitory effect of thymol to tyrosinase activities were examined using both mushroom tyrosinase and intracellular tyrosinase. Expression level of tyrosinase in B16F10 cells were investigated by western blot analysis. Results : The cell viability was decreased by thymol treatment in dose-dependant manner, leading significant cytotoxicity in 500 and $1000{\mu}M$ thymol-treated groups. In the alpha-melanocyte stimulating hormone (${\alpha}$-MSH)-induced melanogenesis, administration of thymol significantly decreased extracellular (secreted) melanin content in dose-dependent manner. Cellular tyrosinase activity assay and western blot analysis of intracellular tyrosinase showed that thymol has a strong anti-melanogenic effect by inhibition of tyrosinase activity and by decreasing expression of tyrosinase that contribute to melanin synthesis in the B1610 cells. Conclusions : As the first functional study that prove anti-melanogenic effect of thymol and its underlying mechanism in the living cells, our study suggests the applicability of fragrance as the functional materials of cosmetics or health supplement, not as just an additive.

Study on Antioxidant Effect of Hoveniae Semen cum Fructus and Hoveniae Ramulus on Liver Cells Isolated from Oxidatively Stressed Rat (산화동물 모델 흰쥐 간세포에 대한 지구자(枳椇子)와 지구지(枳椇枝)의 항산화 효과 연구)

  • Choi, Jeong-Kook;Han, Hyo-Sang;Lee, Young-Jong
    • The Korea Journal of Herbology
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    • v.24 no.3
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    • pp.129-138
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    • 2009
  • Objectives : The Objective of this study is to compare the anti-oxidative effect of the Hoveniae Semen cum Fructus (HScF) to that of Hoveniae Ramulus (HR) in vivo. Methods : The extracts of HScF and HR were tested in vivo for their anti-oxidative effects. SD Rats were injected with the AAPH (2.2'-azobis (2-aminodinopropane) hydrochloride) to induce the acute oxidization stress, and the oxidized rats were administered with the HScF and HR decoction orally. The RBC, WBC and PLT populations in plasma, and the blood chemistry levels of the rats were measured to observe the overall changes in the blood. The anti-oxidative effects of the HScF and HR decoctions were investigated on the liver tissues of the oxidated rats. Results : 1. Thrombocyte decreased significantly in the group medicated with HScF. 2. Blood glucose increased significantly in the group medicated with HR. 3. SOD activity increased significantly in both the group medicated with HScF and that with HR. 4. NO concentration decreased significantly in both the group medicated with HScF and that with HR. 5. The catalase content increased significantly in both the group medicated with HScF and that with HR. Conclusions : The HScF and HR extracts have an anti-oxidative effect.

Experimental Investigation on the Compression Behavior of Concrete Filled Circular FRP Tubes (콘크리트 충전 FRP 원통관의 압축거동에 관한 실험적 연구)

  • Joo, Hyung-Joong;Lee, Seung-Sik;Kim, Young-Ho;Park, Jong-Hwa;Yoon, Soon-Jong
    • Composites Research
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    • v.21 no.3
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    • pp.24-30
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    • 2008
  • Durability problems may arise in the concrete, which is one of the major construction materials, used in the construction field. Bridge piers and foundation piles are usually made with concrete and they are exposed to the moisture and hence the durability of the concrete reduced significantly due to oxidization of re-bar and icing of concrete. To mitigate such problems, FRP tube has been developed and the concrete filled FRP tube (CFFT) has been investigated to find the confinement effect which is provided additionally. It was reported that if the concrete is wrapped with FRP, strength and chemical resistance are improved significantly. In order to apply such a member in the construction field, structural behavior and applicable design guideline or design criteria must be thoroughly investigated. In the experimental investigation, the results are compared with the previous research results and the relationship which can predict the ultimate strength and strain is suggested. In addition, some comments found at the compression tests are given briefly.

HPLC-MS/MS Detection and Sonodegradation of Bisphenol A in Water (HPLC-MS/MS를 이용한 Bisphenol A 분석 및 초음파에 의한 분해 특성 조사)

  • Park, Jong-Sung;Yoon, Yeo-Min;Her, Nam-Guk
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.6
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    • pp.639-648
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    • 2010
  • The optimal conditions for the analysis of BPA by HPLC-MS/MS was investigated and the ultrasound degradation capacity of the BPA, with the goal to establish the proper directions for analyzing infinitesimal quantities of BPA by HPLC-MS/MS was examined. The MDL and LOQ of BPA analyzed by HPLC-MS/MS were measured 0.13 nM and 1.3 nM respectively, its sensitivity about 620 and 32 times greater than HPLC-UV (MDL: 81.1 nM, LOQ: 811 nM) and FLD (MDL: 4.6 nM, LOQ: 46 nM). In other words, the new method enables the analysis of BPA with the accuracy up to one 1,180th of the amount specified in U.S. EPA guideline for drinking water. Degradation rate of BPA by ultrasound measured over 95% under 580 kHz and 1000 kHz frequency within 30 minutes of treatment, whereas the rate showed some decrease at 28 kHz frequency. At 580 kHz of ultrasound has proven to be the most effective among others at degradation rate and $k_1$ value, so we concluded that this frequency of ultrasound creates hospitable condition for the combined process of degradation by pyrolysis and oxidization. With the addition of 0.01 mM of $CCl_4$, BPA with the initial concentration of 1 ${\mu}M$ was degraded by more than 98% within 30 minutes, the $k_1$ value measured 5 minutes and 30 minutes into the experiment both showed increases by 1.4 and 1.1 times, respectively, compared with BPA without $CCl_4$. It is also found that the main degradation mechanism of BPA by ultrasound is oxidization process by OH radical, based on the fact that the addition of 10 mM of t-BuOH decreased the rate of BPA degradation by around 60%. However, 33% of BPA degradation rate obtained with the addition of t-BuOH implies further degradation done by pyrolysis or other sorts of radical beside OH radical.

Effect of Taeeumjoweetang on the Body Composition, Serum Lipid Level and Antioxidant Enzyme Activity of Obese Female College Students (태음조위탕의 적용이 태음인 비만여대생의 신체조성, 혈청지질농도 및 혈중 항산화 효소에 미치는 효과)

  • Kim, Hye-Ju;Ahn, Hong-Seok;Oh, Eun-Ha;Kim, Young-Locke
    • Journal of Sasang Constitutional Medicine
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    • v.23 no.3
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    • pp.391-401
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    • 2011
  • 1. Objectives: Though the eating habits have improved and the living method has become convenient according to the economic growth thanks to the modern industrialization, because of the lack of exercise, obesity, wrong eating habits and stress etc, various symptoms of disease of adults are on the rise. This is the phenomenon that happens as the eating life has become life in the West along with the inundation of the western culture in our society. In this perspective, there has been many various clinical research that's been proceeded so far about the physical constitution and obesity, but there has been little research on the objective analysis of the clinical research about the alimentotherapy using taeeumjoweetang. 2. Methods: In this research we have checked the weights, fat rates, fat weight, abdominal fat rate, blood pressure, and BMI over the objects of the women that were diagnosed as lunisolar system as their physical constitution, and assessed the paramecium lipid, in-blood antioxidation enzyme and the damage of oxidization in the urine by physical constitution-specific of the body shapes that were determined by BMI. The statistical analysis of the current research was processed by using of SPSS 17.0 program. We have figure out statistical amounts such as the arithmetic average, average deviation rate and percentage number. Fro the verification of he significancy of each elements, we have used the paired t-test, ANOVA, Chi-square test at the level of p<0.05. 3. Results and Conclusions: Their characteristics are age $21.20{\pm}1.35$, height $160.30{\pm}6.11cm$, weight $64.66{\pm}8.72kg$, fat rates are $35.97{\pm}4.87%$, fat amount $23.40{\pm}5.48$, abdominal fat rate $0.823{\pm}0.03$, BMI $25.12{\pm}2.79kg/m^2$, and systolic blood pressure $111.60{\pm}10.28mmHg$ and diastolic blood pressure $68.60{\pm}7.43mmHg$ and we have let them take the medicine twice a day for 8 weeks. The clinical result for the Cholesterol, Triglyceride, HDL-cholesterol, LDL-cholesterol, SGOT, SGPT, of the object people was that for the function of the liver, the result of the SGOT and SGPT test was $17.16{\pm}3.05$, $15.00{\pm}2.99IU/L$, which was a decrease, and had statistical meaning, but for the SGOT, though the figure reduced to $11.92{\pm}4.61$, $10.80{\pm}3.07$, it had no statistical meaning. For the whole cholesterol level, the figure reduced to $169.00{\pm}19.95$, $160.08{\pm}22.52$ mg/dL and had statistical significance(p<0.05). Neuter fat number, Triglyceride has slightly increased to $67.52{\pm}36.32$, $68.08{\pm}47.33$ mg/dL but did not have any statistical meaning. The antioxdant enzyme marker standard marker, SOD has increased to $2.52{\pm}0.73$, $2.86{\pm}0.60U/ml$, and had statistical significance(p<0.01). Catalase also increased by $0.63{\pm}0.18$, $1.07{\pm}0.25mmol/ml$ and had statistical meaning(p<0.01). GPx also increased to $204.76{\pm}32.64$ nmol/ml and had statistical meaning(p<0.01). But, for the Total antioxidant, though it has raised to $1.51{\pm}0.26$, $1.57{\pm}0.17nmol/{\mu}l$, it did not have any statistical meaning. MDA of oxidative stress marker has decreased to $1.70{\pm}0.68{\mu}g/ml$, $1.21{\pm}0.50{\mu}g/m$ and had statistical significance(p<0.01). 8-OHdG also decreased $3.35{\pm}0.95ng/ml$, $2.21{\pm}0.50ng/ml$ and had statistical meaning(p<0.01). In this research, we have analyzed the various markers relating to BFM and changes in oxidative enzyme in blood by takingtaeeumjoweetang. Taeeumjoweetang has the positive effect on inbody antioxidant system and reducing the content of cholesterol, which is proven to help losing weight and improving hyperlipidemia statistically. With this research, we hope to improve the lifestyle of those who are either obese or need to manage their dietary habits, and also to become the touchstone of integrating Oriental Medicine with the science of food & nutrition.

Magnetic Tunnel Junctions with AlN and AlO Barriers

  • Yoon, Tae-Sick;Yoshimura, Satoru;Tsunoda, Masakiyo;Takahashi, Migaku;Park, Bum-Chan;Lee, Young-Woo;Li, Ying;Kim, Chong-Oh
    • Journal of Magnetics
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    • v.9 no.1
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    • pp.17-22
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    • 2004
  • We studied the magnetotransport properties of tunnel junctions with AlO and AlN barriers fabricated using microwave-excited plasma. The plasma nitridation process provided wider controllability than the plasma oxidization for the formation of MTJs with ultra-thin insulating layer, because of the slow nitriding rate of metal Al layers, comparing with the oxidizing rate of them. High tunnel magnetoresistance (TMR) ratios of 49 and 44% with respective resistance-area product $(R{\times}A) of 3 {\times} 10^4 and 6 {\times} 10^3 {\Omega}{\mu}m^2$ were obtained in the Co-Fe/Al-N/Co-Fe MTJs. We conclude that AlN is a hopeful barrier material to realize MTJs with high TMR ratio and low $R{\times}A$ for high performance MRAM cells. In addition, in order to clarify the annealing temperature dependence of TMR, the local transport properties were measured for Ta $50{\AA} /Cu 200 {\AA}/Ta 50 {\AA}/Ni_{76}Fe_{24} 20 {\AA}/Cu 50 {\AA}/Mn_{75}Ir_{25} 100 {\AA}/Co_{71}Fe_{29} 40 {\AA}/Al-O$ junction with $d_{Al}= 8 {\AA} and P_{O2}{\times}t_{0X}/ = 8.4 {\times} 10^4$ at various temperatures. The current histogram statistically calculated from the electrical current image was well in accord with the fitting result considering the Gaussian distribution and Fowler-Nordheim equation. After annealing at $340^{\circ}C$, where the TMR ratio of the corresponding MTJ had the maximum value of 44%, the average barrier height increased to 1.12 eV and its standard deviation decreased to 0.1 eV. The increase of TMR ratio after annealing could be well explained by the enhancement of the average barrier height and the reduction of its fluctuation.

Interface Functional Materials for Improving the Performance and Stability of Organic Solar Cell (유기태양전지의 효율 및 수명 향상을 위한 기능성 계면 소재 연구)

  • Hong, Kihyon;Park, Sun-Young;Lim, Dong Chan
    • Applied Chemistry for Engineering
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    • v.25 no.5
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    • pp.447-454
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    • 2014
  • Organic solar cells (OSCs) have intensively studied in recent years due to their advantages such as cost effectiveness and possibility of applications in flexible devices. In spite of the high power conversion efficiency (PCE) of 10 %, the OSCs still have a draw back of their low environmental stability due to the oxidization of aluminum cathode and etching of transparent conducting oxide as electrode. To solve these problems, the inverted structured OSCs (I-OSCs) having greatest potential for achieving an improvement of device performances are suggested. Therefore, there are a lot of studies to develope of interface layer based on organic/inorganic materials for the electron transport layer (ETL) and passivation layer, significant advancements in I-OSCs have driven the development of interface functional materials including electron transport layer. Recent efforts to employing 2D/3D zinc oxide (ZnO) based ETL into I-OSCs have produced OSCs with a power conversion efficiency level that matches the efficiency of ~9 %. In this review, the technical issues and recent progress of ZnO based ETL in I-OSCs to enhancement of device efficiency and stability in terms of materials, process and characterization have summarized.

Effect of Interfacial Bonding on Piezoresistivity in Carbon Nanotube and Reduced Graphene Oxide Polymer Nanocomposites (탄소나노튜브 및 환원된 산화그래핀과 고분자간 계면결합력이 나노복합재의 압전 거동에 미치는 영향)

  • Hwang, Sang-Ha;Kim, Hyeon-Ju;Sung, Dae-Han;Jung, Yeong-Tae;Kang, Ku-Hyek;Park, Young-Bin
    • Journal of Adhesion and Interface
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    • v.13 no.3
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    • pp.137-144
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    • 2012
  • Chemical functionalization of carbon nanomaterials (CNMs) is generally carried out for increasing interfacial adhesion between filler and polymer matrix for CNM-polymer nanocomposites. The chemically functionalized CNTs can produce strong interfacial bonds with many polymers, allowing CNT based nanocomposites to possess high mechanical and functional properties. Hence, increased surface adhesion can be measured indirectly by observing increased mechanical properties. However, there is a more direct way to observe interfacial bonds between polymer and CNM by measuring piezoresistivity behavior so that we can imagine the behavior of CNM particles in polymer matrix under deflection. Fuctionalization of MWCNT and rGO was carried out by oxidization reaction of MWCNT and rGO with $H_2SO_4/HNO_3$ solution. Electrical resistivities of MWCNT-PMMA and rGO-PMMA composites were decreased after functionalization because of the destructive fuctionalization process. Meanwhile, piezoresistivities of functionalized CNM-PMMA composites showed more sensitive behavior under the same deflection as compared to pristine CNM-PMMA composites. Therefore, mobility of CNM in polymer matrix was found to be improved with chemical functionalization.