• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.208-208
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• 2013

• Journal of the Korean institute of surface engineering
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• v.44 no.3
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• pp.75-81
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• 2011

Growth behaviors of iron-nitride on S45C steels at low pressure gas nitriding were examined. Surfaces of the steels covered with fine and porous oxide during the pre-oxidation using $N_2O$ gas. Well faceted particles connected with them were observed after 1 min nitriding. They grew steadily and filled inter-pores during additional nitriding process. From the X-ray diffraction analysis, ${\gamma}'$-iron nitride was dominantly formed at the initial stage but the amount of ${\varepsilon}$-iron nitride was rapidly increased as nitriding treatment time. The porous layer was formed on the particles and thickened up to half of nitride layer after 60 min nitriding. The observed growth behaviors were discussed in internal stress related with volume expansion involved in transforming from iron to iron-nitrides.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.178-184
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• 2007

In the present work, the vermicomposting index was investigated using leakage water from sludge to develop the process of mechanization and automation in the earthworm-cast treatment. The in situ sewage sludge was used batch and continuous experiments. Due to different treatment processes, the physico-chemical characteristics of liquid extracted from sludge was the similar change pattern. However, some items, such as Oxidation Reduction Potential (ORP), pH, Electrical Conductivity (EC) and $NH_3-N$, showed the distinct changes between pre- and post-vermicomposting. Also, The ORP and EC were the best parameters for the vermicomposting index. These results offered that the present vermicomposting technology was an actual earthworm-cast treatment.

• CELLMED
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• v.8 no.3
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• pp.11.1-11.6
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• 2018

In vitro anti-obesity effects of anti-cancer (AC) functional kimchi in differentiated 3T3-L1 adipocytes were studied. We constructed three experimental groups: Control, standardized kimchi (SK), and AC functional kimchi (A-FK) that included active ingredients and Lactobacillus plantarum. Kimchi extracts did not show any cytotoxicity in pre-adipocytes in the concentration range of 1 - 5 mg/mL. A-FK significantly reduced fat droplet formation and absorbance in differentiated 3T3-L1 adipocytes, as shown by Oil red O staining, compared to Control and SK (P < 0.05). SK and A-FK reduced adipo-/lipogenesis related genes such as $C/EBP{\alpha}$, SREBP-1, LPL, and $LXR{\alpha}$ compared to Control (P < 0.05). Especially, A-FK more greatly reduced SREBP-1 and LPL compared to SK (P < 0.05). A-FK up-regulated the ${\beta}$-oxidation related gene CPT-1c and down-regulated the pro-inflammatory cytokine IL-6 compared to Control (P < 0.05). Based on the results, A-FK exhibited anti-obesity effects by inhibiting fat droplet formation and adipo-/lipogenesis related genes by regulating the ${\beta}$-oxidation related gene CPT-1c and pro-inflammatory cytokine IL-6. In previous studies, A-FK kimchi already exhibited a strong anti-cancer effect. These results indicate that A-FK increased anti-obesity activity in this model system due to its functional ingredients and anti-cancer functionality.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.597-609
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• 2020

Accident Tolerant Fuels have been widely studied since the Fukushima-Daiichi accident in 2011 as one of the options on how to further enhance the safety of nuclear power plants. Deposition of protective coatings on nuclear fuel claddings has been considered as a near-term concept that will reduce the high-temperature oxidation rate and enhance accidental tolerance of the cladding while providing additional benefits during normal operation and transients. This study focuses on experimental testing of Zr-based alloys coated with Cr-based coatings using Physical Vapour Deposition. The results of long-term corrosion tests, as well as tests simulating postulated accidents, are presented. Zr-1%Nb alloy used as nuclear fuel cladding serves as a substrate and Cr, CrN, Cr_xN_y layers are deposited by unbalanced magnetron sputtering and reactive magnetron sputtering. The deposition procedures are optimized in order to improve coating properties. Coated as well as reference uncoated samples were experimentally tested. The presented results include standard long-term corrosion tests at 360℃ in WWER water chemistry, burst (creep) tests and mainly single and double-sided high-temperature steam oxidation tests between 1000 and 1400℃ related to postulated Loss-of-coolant accident and Design extension conditions. Coated and reference samples were characterized pre- and post-testing using mechanical testing (microhardness, ring compression test), Thermal Evolved Gas Analysis analysis (hydrogen, oxygen concentration), optical microscopy, scanning electron microscopy (EDS, WDS, EBSD) and X-ray diffraction.

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.273-281
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• 2020

Constructing and making highly active and stable nanostructured Pt-based catalysts with ultralow Pt loading are still electrifying for electrochemical applications such as water electrolysis and fuel cells. In this study, MoO₃ ribbons (RBs) of few micrometer in length is successfully synthesized via hydrothermal synthesis. Subsequently, 3-dimentional (3D)-silicate layer for about 10 to 15 nm is introduced via chemical deposition onto the pre-formed MoO₃ RBs; to setup the platform for Pt metaldots (MDs) deposition. In comparison with the bare MoO₃ RBs, the MoO₃-Si has served as a efficient solid-support for stabilizing and accommodating the uniform deposition of sub-2 nm Pt MDs. Such a structural design would effectively assist in improving the electronic conductivity of a fabricated MoO₃-Si-Pt catalyst towards MOR; the interfaced, porous and 3D silicate layer has assisted in an efficient mass transport and quenching the poisonous CO_ads species leading to a significant electrocatalytic performance for MOR in alkaline medium. Uniformly decorated, sub-2 nm sized Pt MDs has synergistically oxidized the MeOH in association with the MoO₃-Si solid-support hence, synergistic catalytic activity has been achieved. Present facile approach can be extended for fabricating variety of highly efficient Metal Oxide-Metal Nanocomposite for energy harvesting applications.

• Membrane and Water Treatment
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• v.11 no.4
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• pp.257-274
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• 2020

There are many previous review articles are available to summarize either the characterization methods of effluent organic matter (EfOM) or the individual control treatment options. However, there has been no attempt made to compare in parallel the physicochemical treatment options that target the removal of EfOM from biological treatments. This review deals with the recent progress on the characterization of EfOM and the novel technologies developed for EfOM treatment. Based on the publications after 2010, the advantages and the limitations of several popularly used analytical tools are discussed for EfOM characterization, which include UV-visible and fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), size exclusion chromatography (SEC), and Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS). It is a recent trend to combine an SEC system with various types of detectors, because it can successfully track the chemical/functional composition of EfOM, which varies across a continuum of different molecular sizes. FT-ICR-MS is the most powerful tool to detect EfOM at molecular levels. However, it is noted that this method has rarely been utilized to understand the changes of EfOM in pre-treatment or post-treatment systems. Although membrane filtration is still the preferred method to treat EfOM before its discharge due to its high separation selectivity, the minimum requirements for additional chemicals, the ease of scaling up, and the continuous operation, recent advances in ion exchange and advanced oxidation processes are greatly noteworthy. Recent progress in the non-membrane technologies, which are based on novel materials, are expected to enhance the removal efficiency of EfOM and even make it feasible to selectively remove undesirable fractions/compounds from bulk EfOM.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.723-731
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• 2013

This study provides a comparative analysis of the effects of pre-slaughter penetrative and non-penetrative stunning and post-slaughter stunning on meat quality attributes in longissimus lumborum (LL) and semitendinosus (ST) muscles in heifers. Ten animals were assigned to each of four treatment groups: i) animals were subjected to conventional Halal slaughter (a clean incision through the structures at the front of the upper neck - the trachea, oesophagus, carotid arteries and jugular veins) and post-cut penetrating mechanical stun within 10 to 20 s of the neck cut (Unstunned; US); ii) high power non-penetrating mechanical stunning followed by the neck cut (HPNP); iii) low power non-penetrating mechanical stunning followed by the neck cut (LPNP); and iv) penetrative stunning using a captive bolt pistol followed by the neck cut (P). For each carcass, muscle samples were removed within 45 min of slaughter, portioned and analysed for pH, cooking loss, water holding capacity (WHC), tenderness (WBS), lipid oxidation (TBARS) and color, over a two week storage period. Stunning did not affect pH and cooking loss. Significant differences in water holding capacity, tenderness, lipid oxidation and color were present at different storage time points. HPNP stunning resulted in lower WHC and color values, particularly lightness ($L^*$), higher TBARS values and peak force values compared with those stunned using LPNP, P and US. These adverse effects on quality were mostly encountered in the ST muscle. In conclusion, the meat quality achieved using P, LPNP and US treatments was comparable, and no treatment stood out as considerably better than another.

• BMB Reports
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• v.34 no.6
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• pp.544-550
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• 2001

In pre-transplant total-body irradiation (TBI), the lung is a critical dose-limiting organ. Also, the possible role of oxidative stress was suggested in the development of TBI-induced lung damage. This study explores the association between TBI-induced oxidative stress and the induction of lung pathogenesis by investigating TBI-induced oxidative stress in the lungs of male C57BL/6 mice after a single dose of 10 Gy TBI. We showed significant increases of reactive oxygen species (ROS) formation and lipid peroxidation, and also a depletion and oxidation of glutathione after TBI. There is evidence that pretreatment with 1,10-phenanthroline (o-phen) significantly reduces oxidative stress in the lung. This indicates that the TBI-induced ROS generation involves a metal-catalyzed Fenton-type reaction. A pretreatment of buthionine sulfoximine (BSO) augmented the glutathione depletion and oxidation, but had no effect on the ROS formation and lipid peroxidation up to 6 h after TBI. Histopathological features that are consistent with pneumonitis were observed in the BSO pretreated-mice 1 week after irradiation. The results suggest that TBI-induced oxidative stress in the lung involves a generation of ROS through a Fenton-type reaction. Also, glutathione plays an important inhibitory role in the radiation-induced lung pathogenesis by participating in the self-amplifying cascade subsequent to the ROS generation by irradiation.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.80-80
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• 2017

Titanium and its alloys that have a good biocompatibility, corrosion resistance, and mechanical properties such as hardness and wear resistance are widely used in dental and orthopedic implant applications. However, they do not form a chemical bond with bone tissue. Plasma electrolytic oxidation (PEO) that combines the high voltage spark and electro-chemical oxidation is a novel method to form ceramic coatings on light metals such as tita-nium and its alloys. This is an excellent re-producibility and economical, because the size and shape control of the nano-structure is relatively easy. Silicon (Si), manganese (Mn), and magne-sium (Mg) have a useful to bone. Particularly, Si has been found to be essential for normal bone, cartilage growth, and development. Mn influences regulation of bone remodeling be-cause its low content in body is connected with the rise of the concentration of calcium, phosphates and phosphatase out of cells. Pre-studies have shown that Mg plays very im-portant roles in essential for normal growth and metabolism of skeletal tissue in verte-brates and can be detected as minor constitu-ents in teeth and bone. In this study, Electrochemical behavior of plasma electrolytic oxidized films formed in solution containing Mn, Mg and Si ions were researched using various experimental in-struments. A series of Si-Mn-Mg coatings are produced on Ti dental implant using PEO, with the substitution degree, respectively, at 5 and 10%. The potentiodynamic polarization and AC impedance tests for corrosion behav-iors were carried out in 0.9% NaCl solution at similar body temperature using a potentiostat with a scan rate of 1.67mV/s and potential range from -1500mV to + 2000mV. Also, AC impedance was performed at frequencies anging from 10MHz to 100kHz for corrosion resistance.