• Environmental Engineering Research
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• v.12 no.1
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• pp.30-35
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• 2007

Fenton system using homogeneous iron catalyst is very powerful in the degradation of organic compounds, but has a disadvantage to remove Fe ions from water after wastewater treatment. Thus, iron catalyst was bounded to support such as inorganic and polymer materials. The PVP supporting iron catalyst showed a good catalytic performance in degradation of phenol contained in waste water and iron catalyst supported on ${SO_4}^{2-}$ type PVP (KEX 511) showed the best catalytic performance. Also, reaction kinetic study was carried out in this system. Reaction constants on various catalysts was obtained from the pseudo first order equation. Reaction rate constants with the heterogenized $FeCl_2/PVP$ catalyst is a three-fold smaller than that of $FeCl_2$ catalyst.

• Journal of the Korean Society for Heat Treatment
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• v.31 no.3
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• pp.120-125
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• 2018

The PMMA composited material mixed with alumina studied to find the optimal condition, the adequate ratio of mixing, for the associated mechanical properties such as anti-corrosive, weatherproof performance. The 80% of hardness and 52% of scratch coefficient improved according to increasing ratio of alumina, which is mostly 3 times higher than that of pure PMMA, on other hand 16% of tensile strength and 35% of flexural strength has lost while alumina was adding in. The most proper ratio, having the best availability in substantial production, of composite between pure PMMA and alumina is determined as 93 wt. % vs 7 wt. %. Results of related five properties had estimated by using of a pentagram.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.425-429
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• 2009

The protection for copper tarnish was developed by surface treatment method and volatile corrosion inhibiting (VCI) technology. The performance of surface treatment and VCI material is also examined in simulated test environment. Benzotriazole (BTAH) solution that contained molybdate showed best performance than others. Usage of VCI materials with surface treatment was more effective. The protection film foamed on the surface of copper was investigated by auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). Molybdate does not participate in the formation of the protective film but promotes the passivation effect. This facilitates the stabilization of the cuprous oxide film, and strengthens the adsorption of BTAH.

• Korean Journal of Medicinal Crop Science
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• v.19 no.4
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• pp.233-237
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• 2011

This study was carried out to investigate the seedling establishment and yield of direct-sown Platycodon grandiflorus seeds cultured by three ridge width, 0.4, 0.8, and 1.2 m and four mulching materials, rice straw, rice bran, black plastic film, and no mulching in upland. Seedling establishment rate (70%) was the highest in rice straw mulched plot of 500 seeds/$m^2$ sowed and root yield after one year was also the highest in rice straw mulched treatment and followed by rice bran, no mulching, and black plastic film treatment. In this result, ridge width 120cm and rice straw mulching combined treatment was best for getting the highest seedling establishment ratio and seedling numbers per area. However, ridge width and mulching materials should be considered soil moisture content and weed population for saving labor cost.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.412-417
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• 2015

The purpose of this study is to treat the ballast water by shear stress without an environmental pollution and to find out the optimal treatment conditions. The ballast water problem is issued up as the trade activated and the cargos mobilized. To improve this problem, International Marine Organization(IMO) make the rule about the ballast water treatment with specific restrictions. Although many countries have been studying about the ballast water treatment technology, there is almost no technology that can treat the microorganisms under $50{\mu}m$ without any secondary pollution. In this study, we tried to treat ballast water by applying shear stress as the physical treatment for the sterilization and tried to find out the optimal conditions including the 100% sterilizing rate and the best economic condition.

• Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.231-242
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• 2022

Effect of different concentrations of hypotaurine (HTU) on melanosis and quality of shrimps during 10 d storage in ice were studied. During refrigeration, the total plate count and total volatile basic nitrogen of shrimps treated with 20 g/L HTU were the lowest, and the hardness and microstructure were the best. Moreover, the score of melanoses, pH and total bile acid of shrimps treated with 20 g/L HTU were also low. Sensory evaluation showed that HTU treatment could make the shelf life of shrimps 3-4 days longer compared with the control. Based on the above physical and chemical indexes, 20 g/L HTU showed great potential as a safe inhibitor in the treatment of shrimps' melanosis.

• Archives of Plastic Surgery
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• v.50 no.4
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• pp.331-334
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• 2023

Historically, the approach to any reconstructive challenge, whether intentionally or intuitively, can be seen to follow distinct guidelines that could aptly be called "reconstructive metaphors." These have been intended to inform us as to the "what, "when" and "where" this attempt can best be achieved. Yet the "how" or means to accomplish this goal, usually also intuitively well understood, in a similar vein can now be expressed to be within our "reconstructive toolbox." The latter will distinctly mirror our individuality and contain not only the various hardware that we deem essential, but also the means to access whatever technology we may be comfortable with. No toolbox, even if overflowing will ever be full, as potential options and the diversity they represent surely approaches infinity. But the truly excellent reconstructive surgeon will know when their toolbox is in any way lacking, and fears not remedying that deficiency even if the talents of another colleague must be sought, so as always to ensure that the patient will obtain the best appropriate treatment!

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3787-3800
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• 2023

Reactivity Initiated Accident (RIA) scenarios require special attention using advanced simulation techniques due to their complexity and importance for nuclear power plant (NPP) safety. While the conservative approach has traditionally been used for safety analysis, it may lead to unrealistic results which calls for the use of best estimate plus uncertainty (BEPU) approach, especially with the current advances in computational power which makes the BEPU analysis feasible. In this work an Uncontrolled Control Element Assembly (CEA) Withdrawal at Full Power accident scenario is analyzed using the BEPU approach by loosely coupling the thermal hydraulics best-estimate system code (RELAP5/SCDAPSIM/MOD3.4) to the statistical analysis software (DAKOTA) using a Python interface. Results from the BEPU analysis indicate that a realistic treatment of the accident scenario yields a larger safety margin and is therefore encouraged for accident analysis as it may enable more economic and flexible operation.

• Journal of Electrochemical Science and Technology
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• v.15 no.1
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• pp.178-189
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• 2024

This work aims to investigate the efficiency of electrocoagulation (EC) of pistachio processing industrial wastewater (PPIW) using the continuous EC process. The tubular reactor made of stainless steel with an internal diameter of 60 mm was used as a cathode electrode. The effect of some parameters was examined on the removal of chemical oxygen demand (COD) and total phenols (TP) removal efficiency. The influences of the initial pH of wastewater (from 4 to 8), flow rate (from 25 to 125 mL/min), current density (from 7 to 21 mA/cm²), and supporting electrolyte type (NaCl, NaNO₃, and Na₂SO₄), supporting electrolyte concentration (from 10 to 100 mg/L NaCl) on removal efficiency were investigated to determine the best experimental conditions. The examination of the physico-chemical parameters during the EC treatment showed that the best removal efficiency was obtained under conditions where the flow rate was 25 mL/min (20 min reaction time), the pH value was 5.2, and the current density was 21 mA/cm² has set. Under these experimental conditions, COD and TP removal efficiency were found to be 75% and 97%, respectively, while energy consumption was 18.5 kW h/m³. The study results show that the EC can be applied to PPIW pre-treatment.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.5
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• pp.513-518
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• 2004

The effect of polyethylene film(PE) packaging of golden mushroom wrapped with Korean paper containing 20% mica powder on the changes in weight, color, texture, PPO activity, number of total microbe(TM) and sensory quality during storage at 10℃ were investigated. The experiments were divided to 3 groups(control; only PE packaging, KP; PE packaging wrapped with Korean paper up and down of the sample, KPM; PE packaging with Korean paper containing 20% mica powder up and down of the sample). The weight of the mushroom in the KPM was the lowest until 9 days-storage, but the weight was the highest at 15 days-storage, showing 12.5% higher against the initial weight. L* values of the mushrooms in the control and KP treatment were decreased, but the value in the KPM treatment was maintained as the same of the initial value during storage. The increasing rate of a* and b* values in the all plots during storage was the lowest in KPM and in order of KPM