• Progress in Superconductivity and Cryogenics
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• v.21 no.2
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• pp.22-25
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• 2019

The superconducting magnetic separation system has been developing to separate the iron oxide scale from the feed water of the thermal power plant. The accumulation in the boiler lowers the heat exchange rate or in the worst case damages it. For this reason, in order to prevent scale generation, controlling pH and redox potential is employed. However, these methods are not sufficient and then the chemical cleaning is performed regularly. A superconducting magnetic separation system is investigated for removing iron oxide scale in a feed water system. Water supply conditions of the thermal power plant are as follows, flow rate 400 t / h, flow speed 0.2 m / s, pressure 2 MPa, temperature $160-200^{\circ}C$, amount of scale generation 50 - 120 t / 2 years. The main iron oxide scale is magnetite (ferromagnetic substance) and its particle size is several tens ${\mu}m$. As the first step we are considering to introduce the system to the chemical cleaning process of the thermal power plant instead of the thermal power plant itself. The current status of development will be reported.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.4
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• pp.320-329
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• 2019

This study was performed by the numerical approach to investigate chemical behaviors of homogeneous syngas ($CO/H_2$) with nitric monoxide (NO) in pressurized oxy-fuel conditions. Hydrogen had a dominant effect to the ignition delay time of syngas due to the fast chemistry of its oxidation. Combustion was promoted by NO at the low temperature region. It was by the additional heat release through NO oxidation and production and consumption of major radicals related to the ignition. Two stage ignition behavior was shown in the pressurized condition by the accumulation of $H_2O_2$ produced from $HO_2$ radical. Additional NO oxidation was induced by the pressurized oxy-fuel condition to produce $NO_2$.

• Korean Journal of Materials Research
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• v.29 no.6
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• pp.378-384
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• 2019

Ice accumulation on Aluminum Conductor Steel Reinforced(ACSR) cable during winter is an important matter in terms of safety, economy, and efficient power supply. In this work, the ice adhesion strengths of ACSR cable oxidized during different periods(7 years oxidized and 15 years oxidized) are evaluated. At first, a plate type dry oxidation standard specimen, whose surface characteristics are similar to those of ACSR cable, is prepared. Dry oxidation standard specimens are heat-treated at $500^{\circ}C$ for 20, 60, and 120 minutes in order to obtain different degrees of oxidation. After the dry oxidation, surface properties are analyzed using contact angle analyzer, atomic force microscopy, spectrophotometer, and gloss meter. The ice adhesion strengths are measured using an ice pull-off tester. Correlations between the surface properties and the ice adhesion strength are obtained through a regression analysis indicating a Boltzmann equation. It is revealed that the ice adhesion strength of 15-year oxidized ACSR cable is approximately 8 times higher than that of ACSR-bare.

• Korean Journal of Heritage: History & Science
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• v.36
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• pp.157-179
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• 2003

The smith's tool is a tool used for the forging that directly heat-treats and treats ironware. Smith's tools have been thus far excavated from 58 archaeologic sites in Korea, which include 46 hammers, 40 nippers, 5 tweezers, 17 chisels, and 12 anvils, totaling to 120 items. The historic sites from which smith's tools have been excavated indicate 2 sites in Nangnang, 6 in Goguryo, 30 in Silla, 3 in Baekjae, 15 in Gaya, and other 2 sites. Those smith's tools excavated from tumuli in the Three Kingdoms period in Korea are known to be those from the Silla and Gaya areas, and some have been found in the Goguryo and Baekjae areas but require more accumulation of artifacts. Furthermore, the result of having investigated those smith's tools burnt with the corpse in tumulus revealed that smith's tool owners are classified into the blacksmiths who were directly engaged in manufacture and the ruling class who controlled them. Moreover, the smith's tools excavated from large-sized tumulus are presumed to have the potential that symbolically exhibits smithy-iron working, as compared with other funerary objects. Key words: smith's tool, blacksmith, manager.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.357-371
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• 2016

Buildings in the city acts as a cause of distorted wind direction, wind speed, causing the stagnation of the air flow. In the recent trend of climate change can not but consider the temperature rise of the urbanization. This study was aimed to analyze the thermal comfort of planetary boundary layer in different artificial constructions areas which has a direct impact on urban climate, and estimating the warming phenomena. Envi-met model was used to consider the urban structure associated with urban growth in order to precisely determine the impact of the building on the city weather condition. The analyzed values of thermal comfort index were temperature, wind speed, horizontal and vertical turbulent diffusivity. In particular, analysis of the PPD(Predicted Percentage of Dissatisfied) represents the human thermal comfort. In this study, by adjusting the arrangement and proportion of the top floor building in the urban it was found that the inflow of the fresh air and cooling can be derived low PPD. Vertical heat flux amount of the city caused by climate change was a factor to form a high potential temperature in the city and the accumulation of cold air does not appear near the surface. Based on this, to make the city effectively respond to climate change may require a long-term restructuring of urban spatial structure and density management.

• Food Science and Industry
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• v.50 no.1
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• pp.26-35
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• 2017

Obesity is a worldwide problem that is associated with metabolic disorders. Obesity is caused by the accumulation of an abnormal amount of body fat in adipose tissue. Adipose tissue is a major metabolic organ, and it has been classified as either white adipose tissue (WAT) or brown adipose tissue (BAT). WAT and BAT are characterized by different anatomical locations, morphological structures, functions, and gene expression patterns. WAT is mainly involved in the storage and mobilization of energy in the form of triglycerides. On the other hand, BAT specializes in dissipating energy as heat through uncoupling protein-1 (UCP-1)-mediated non-shivering thermogenesis. Novel type of brown-like adipocyte within WAT called beige/brite cells was recently discovered, and this transdifferentiation process is referred to as the "browning" or "britening" of WAT. Recently, Brown fat and/or browning of WAT have been highlights as a new therapeutic target for treatment of obesity and its related metabolic disorders. Here, we describe recent advances in the study of BAT and browning of WAT, focusing on proteomic approaches.

• The Journal of Korean Medicine
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• v.41 no.4
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• pp.100-105
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• 2020

A 25-year-old male presented with influenza-like symptoms and took Western anti-inflammatory analgesic drugs for 2 days. The symptoms aggravated, so the patient decided to rely on Korean medicine (KM). Based on the highly elevated hepatic enzymes (AST 4,621 IU/L and ALT 2,763 IU/L) with a positive result of anti-HAV IgM, he was diagnosed with hepatitis A. The patient was hospitalized and given herbal drugs (Chunggan-plus extract, Innae-Tang) and acupuncture, according to symptom differentiation, the accumulation of damp heat (濕熱蘊結)". The subjective symptoms (fatigue, nausea, gastric discomfort) including jaundice and dark urine as well as laboratory abnormalities gradually improved gradually in 10 hospital days, and the patient completely recovered in 25 days as an out-patient. This case presents a classic case of severe hepatitis A in 2019 Korean outbreak, and is informative to physicians for diagnosis and treatment in the traditional Korean medicine field.

• Journal of the Society of Disaster Information
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• v.10 no.4
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• pp.583-597
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• 2014

Fire caused by heater has various causes as many as the types of heater. also, lots of damage of human life and property loss are caused, since annually continuous fire accident by heater in traditional market is frequently occurring. There are not many cases of fire due to heater in most of residential facilities such as general house, apartments, etc., because they are supplied with heating boiler, however the restaurant, store and office of the market, sports center, factory, workplace, etc. still use heater, e.g. oilstove, electric heater, etc., so that they are exposed to fire hazard. Also, when investigating the number of fire due to heater, it was analyzed to occur in order of home boiler, charcoal stove, oilstove, gas heater/stove, electric stove/heater, the number of fire per human life damage was analyzed in order of gas heater/stove, oil heater/stove, electric heater/stove, briquette/coal heater. Also, gas and oil related heater were analyzed to have low frequency, however, with high fire intensity. Therefore, this research aimed at considering more scientific fire inspection and identification approach by reenacting and reviewing fire outbreak possibility caused by combustibles' contact and conductivity under the normal condition and abnormal condition in respect of ignition hazard, i.e. minimum ignition temperature, carbonization degree and heat flux along with it, due to oilstove and electric stove, which are still frequently used in public use facility, traditional market, and, of which actual fire occurrence is the most frequent. As the result of reenact test, ignition hazard appeared very small, as long as enough heat storage condition is not made in both test objects(oilstove/electric stove), however carbonization condition was analyzed to be proceeded per each part respectively. Eventually, transition to fire is the ignition due to heat storage, so that it was analyzed to ignite when minimum heat storage temperature condition of fire place is over $500^{\circ}C$. Particularly, in case of quartz pipe, the heating element of electric stove, it is rapidly heated over the temperature of $600^{\circ}C$ within the shortest time(10sec), so that the heat flux of this appears 6.26kW/m2, which was analyzed to result in damage of thermal PVC cable and second-degree burn in human body. Also, the researcher recognized that the temperature change along with Geometric View Factor and Fire Load, which display decrease of heat, are also important variables to be considered, along with distance change besides temperature condition. Therefore, the researcher considers that a manual of careful fire inspection and identification on this is necessary, also, expects that scientific and rational efforts of this research can contribute to establish manual composition and theoretical basis on henceforth fire inspection and identification.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.308-314
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• 2005

Both high glucose and glucose degradation products (GDP) have been implicated in alterations of peritoneal membrane structure and function during long-term peritoneal dialysis (PD). The present study examined the role of GDP including methylglyoxal (MGO), acetaldehyde, and 3,4-dideoxyglucosone (3,4-DGE) in HPMC activation with respect to membrane hyperpermeability or fibrosis. The role of reactive oxygen species (ROS) and activation of protein kinase C (PKC) in GDP-induced HPMC activation were also examined. Using M199 culture medium as control, growth arrested and synchronized HPMC were continuously stimulated by MGO, acetaldehyde, and 3,4-DGE for 48 hours. Vascular endothelial growth factor (VEGF) was quantified as a marker of peritoneal membrane hyperpermeability and fibronectin and heat shock protein 47 (hsp47) as markers of fibrosis. Involvement of ROS and PKC was examined by the inhibitory effect of N-acetylcystein (NAC) or calphostin C, respectively. MGO significantly increased VEGF (1.9-fold), fibronectin (1.5-fold), and hsp47 (1.3-fold) secretion compared with control M199. NAC and calphostin C effectively inhibited MGO-induced VEGF upregulation. Acetaldehyde stimulated and 3,4-DGE inhibited VEGF secretion. Fibronectin secretion and hsp47 expression in HPMC were not affected by acetaldehyde or 3,4-DGE In conclusion, MGO upregulated VEGF and fibronectin secretion and hsp47 expression in HPMC, and PKC as well as ROS mediate MGO-induced VEGF secretion by HPMC. This implies that PKC activation and ROS generation by GDP may constitute important signals for activation of HPMC leading to progressive membrane hyperpermeability and accumulation of extracellular matrix and eventual peritoneal fibrosis.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.39-41
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• 2008

The yeast Saccharomyces cerevisiae has been shown to contain three isoforms of citrate synthase (CS). The mitochondrial CS, Cit1, catalyzes the first reaction of the TCA cycle, i.e., condensation of acetyl-CoA and oxaloacetate to form citrate [1]. The peroxisomal CS, Cit2, participates in the glyoxylate cycle [2]. The third CS is a minor mitochondrial isofunctional enzyme, Cit3, and related to glycerol metabolism. However, the level of its intracellular activity is low and insufficient for metabolic needs of cells [3]. It has been reported that ${\Delta}cit1$ strain is not able to grow with acetate as a sole carbon source on either rich or minimal medium and that it shows a lag in attaining parental growth rates on nonfermentable carbon sources [2, 4, 5]. Cells of ${\Delta}cit2$, on the other hand, have similar growth phenotype as wild-type on various carbon sources. Thus, the biochemical basis of carbon metabolism in the yeast cells with deletion of CIT1 or CIT2 gene has not been clearly addressed yet. In the present study, we focused our efforts on understanding the function of Cit2 in utilizing $C_2$ carbon sources and then found that ${\Delta}cit1$ cells can grow on minimal medium containing $C_2$ carbon sources, such as acetate. We also analyzed that the characteristics of mutant strains defective in each of the genes encoding the enzymes involved in TCA and glyoxylate cycles and membrane carriers for metabolite transport. Our results suggest that citrate produced by peroxisomal CS can be utilized via glyoxylate cycle, and moreover that the glyoxylate cycle by itself functions as a fully competent metabolic pathway for acetate utilization in S. cerevisiae. We also studied the relationship between Cit1 and apoptosis in S. cerevisiae [6]. In multicellular organisms, apoptosis is a highly regulated process of cell death that allows a cell to self-degrade in order for the body to eliminate potentially threatening or undesired cells, and thus is a crucial event for common defense mechanisms and in development [7]. The process of cellular suicide is also present in unicellular organisms such as yeast Saccharomyces cerevisiae [8]. When unicellular organisms are exposed to harsh conditions, apoptosis may serve as a defense mechanism for the preservation of cell populations through the sacrifice of some members of a population to promote the survival of others [9]. Apoptosis in S. cerevisiae shows some typical features of mammalian apoptosis such as flipping of phosphatidylserine, membrane blebbing, chromatin condensation and margination, and DNA cleavage [10]. Yeast cells with ${\Delta}cit1$ deletion showed a temperature-sensitive growth phenotype, and displayed a rapid loss in viability associated with typical apoptotic hallmarks, i.e., ROS accumulation, nuclear fragmentation, DNA breakage, and phosphatidylserine translocation, when exposed to heat stress. Upon long-term cultivation, ${\Delta}cit1$ cells showed increased potentials for both aging-induced apoptosis and adaptive regrowth. Activation of the metacaspase Yca1 was detected during heat- or aging-induced apoptosis in ${\Delta}cit1$ cells, and accordingly, deletion of YCA1 suppressed the apoptotic phenotype caused by ${\Delta}cit1$ mutation. Cells with ${\Delta}cit1$ deletion showed higher tendency toward glutathione (GSH) depletion and subsequent ROS accumulation than the wild-type, which was rescued by exogenous GSH, glutamate, or glutathione disulfide (GSSG). Beside Cit1, other enzymes of TCA cycle and glutamate dehydrogenases (GDHs) were found to be involved in stress-induced apoptosis. Deletion of the genes encoding the TCA cycle enzymes and one of the three GDHs, Gdh3, caused increased sensitivity to heat stress. These results lead us to conclude that GSH deficiency in ${\Delta}cit1$ cells is caused by an insufficient supply of glutamate necessary for biosynthesis of GSH rather than the depletion of reducing power required for reduction of GSSG to GSH.