• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• v.55 no.6
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• pp.588-595
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• 2018

This study has focused on evaluation of heavy metal contamination in seepage from 23 mine waste dumping sites in Korea. Seepage samples from the sites were taken and analyzed for heavy metals. The maximum levels (mg/L) in the samples were Al 53.98, As 16.19, Cd 1.15 Cu 37.30, Fe 28.64, Mn 39.00, Ni 0.097, Pb 0.750, and Zn 80.18. Among the sites, six mines were selected as continuous monitoring sites. As results of three months' monitoring of the sites, over the water guidelines for As, Cd, Cu, Fe, Mn, Zn and Al in seepage samples were found at two abandoned Au-Ag mines, Cd, Mn, Zn and Al at two Pb-Zn mines, and As, Fe and Mn at two other Fe-W mines. Therefore, those six mines need continuous monitoring on contamination assessment of seepage due to mining activities.

• (The)Study of the Eastern Classic
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• no.72
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• pp.365-400
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• 2018

The signs of $G{\bar{a}}nzh{\bar{i}}$(干支: the sexagesimal calendar system) almanac, which marked each year, month, day and time with 60 ordinal number marks made by combining 10 $Ti{\bar{a}}ng{\bar{a}}ns$(天干: the decimal notation to mark date) and 12 $D{\grave{i}}zh{\bar{i}}s$(地支 : the duodecimal notation to mark date), were used not only as the sign of the factors affecting the occurrence of a disease and treatment in the area of traditional oriental medicine, but also as the indicator of prejudging fortunes in different areas of future prediction techniques.(for instance, astrology, the theory of divination based on topography, four pillars of destiny and etc.) While theories of many future predictive technologies with this $G{\bar{a}}nzh{\bar{i}}$(干支) almanac signs as the standard had been established in many ways by Han dynasty, it is difficult to find almanac discussion later on the fundamental theory of 'how it works like that'. As for the method to mark the era of $Ti{\bar{a}}nt{\check{i}}l{\grave{i}}$(天體曆: a calendar made with the sidereal period of Jupiter and the Sun), which determines the name of a year depending on where $Su{\grave{i}}x{\bar{i}}ng$(歲星: Jupiter) is among the '12 positions of zodiac', there are three main ways of $$Su{\grave{i}}x{\bar{i}}ng-J{\grave{i}}ni{\acute{a}}nf{\check{a}}$$(歲星紀年法: the way to mark an era by the location of Jupiter on the celestial sphere), $$T{\grave{a}}isu{\grave{i}}-J{\grave{i}}ni{\acute{a}}nf{\check{a}}$$ (太歲紀年法: the way to mark an era by the location facing the location of Jupiter on the celestial sphere) and $$G{\bar{a}}nzh{\bar{i}}-J{\grave{i}}ni{\acute{a}}nf{\check{a}}$$(干支紀年法: the way to mark an era with Ganzhi marks). Regarding $$G{\bar{a}}nzh{\bar{i}}-J{\grave{i}}ni{\acute{a}}nf{\check{a}}$$(干支紀年法), which is actually the same way to mark an era as $$T{\grave{a}}isu{\grave{i}}-J{\grave{i}}ni{\acute{a}}nf{\check{a}}$$(太歲紀年法) with the only difference in the name, there are more than three ways, and one of them has continued to be used in China, Korea and so on since Han dynasty. The name of year of $G{\bar{a}}nzh{\bar{i}}$(干支) this year, 2018, has become $W{\grave{u}}-X{\bar{u}}$(戊戌) just by 'accident'. Therefore, in this discussion, the need to realize this situation was emphasized in different areas of traditional techniques of future prediction in which distinct theories have been established with the $G{\bar{a}}nzh{\bar{i}}$(干支) mark of year, month, day and time. Because of the 1 sidereal period of Jupiter, which is a little bit shorter than 12 years, once about one thousand years, 'the location of Jupiter on the zodiac' and 'the name of a year of 12 $D{\grave{i}}zh{\bar{i}}s$(地支) marks' accord with each other just for about 85 years, and it has been verified that recent dozens of years are the very period. In addition, appropriate methods of observing the the twenty-eight lunar mansions were elucidated. As $G{\bar{a}}nzh{\bar{i}}$(干支) almanac is related to the theoretical foundation of traditional medical practice as well as various techniques of future prediction, in-depth study on the fundamental theory of ancient $Ti{\bar{a}}nt{\check{i}}l{\grave{i}}$(天體曆) cannot be neglected for the succession and development of traditional oriental study and culture, too.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.356-359
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• 2004

Above all Ni-alloys Inconel 625 is used widely in plate of welding structural materials such as turbine case, a combustor of liner. In general, weldability of Inconel 625 is not well because of poorly liquids of weld metal also it have a broken probability oj the welding crack. In case of FCAW weld process, it is not easy to develope of welding materials, because it is possible only fillet welding at view position of look down except for butt welding. But recently, though it is more used by FCAW process, owing to welding materials worked at the vertical position. the study for FCAW weld of Inconel 625 is actively not yet worked. In this study, the weldability and weld characteristics(mechanical characteristics, corrosive property) of Inconel 625 are considered in FC4W weld associated with the several shielding gases$80\%Ar\;+\;20\%\;CO_2,\;50\%Ar\;+\;50\%\;CO_2,\;100\%\;CO_2$ in viewpoint of welding productivity. The results of impact test are follows; It was evaluated 70J at shielding gase of $100\%\;CO_2$, and obtained about 35J at the other shielding gases. If it was used for parts be required the impact value at the extremely low temperature, it is expected to have the advantage of using the $100\%\;CO_2$ shield gase than the others.

• Polymer(Korea)
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• v.32 no.4
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• pp.295-304
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• 2008

This study examined the oxidative polycondensation reaction of 2-[(pyridin-4-yl-) methyleneamino] pyridine-3-ol (2-PMAP) using air $O_2$ and NaOCl oxidants at various temperatures and times in aqueous alkaline and acidic media. Under these reactions, the optimum reaction conditions using air $O_2$ and NaOCl oxidants were determined for 2-PMAP. The number-average molecular weight ($M_n$), weight average molecular weight ($M_w$), and polydispersity index (PDI) values of O-2-PMAP synthesized in aqueous alkaline media were found to be 960, 1230, and $1.281\;g\;mol^{-1}$ using NaOCl, and 1030, 1520, and $1.476\;g\;mol^{-1}$ using air $O_2$, respectively. At the optimum reaction conditions, the yield of O-2-PMAP in aqueous alkaline media was 92.50% and 85.70% for air $O_2$ and NaOCl oxidants, respectively. The yield of O-2-PMAP in aqueous acidic media was 88.5% and 88.0% for NaOCl and air $O_2$ oxidants, respectively. O-2-PMAP was characterized by $^1H-$, $^{13}C$-NMR, FT-IR, UV-vis, SEC, and elemental analysis. TGA-DTA analysis revealed O-2-PMAP and its oligomer metal complex compounds, such as $Co^{+2}$, $Ni^{+2}$, and $Cu^{+2}$, to be stable against thermal decomposition and their weight losses at $1000^{\circ}C$ were found to be 73.0, 58.0, 53.5%, and 50.0%, respectively. In addition, the antimicrobial activities of the monomer and oligomer were tested against E. Coli (ATCC 25922), E. Faecelis (ATCC 29212), P. Auroginasa (ATCC 27853), and S. Aureus (ATCC 25923).

• Journal of the Korean Society for Heat Treatment
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• v.11 no.2
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• pp.140-149
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• 1998

The graphitization is affected by the addition of small amount of the elements, such as Si, Al, Ni, B, Cr and Mn etc. Boron is well known as the most effective element for the graphitization of cementite in high carbon steels. But a study on quantitative analysis of B effect on the graphitization is few reported. Therefore the effect of boron addition in Fe-0.65%C-1.0%Si-0.5%Mn steels on the graphitization is investigated quantitatively using hardness tester, optical microscope and scanning electron microscope, neutron induced microscopic radiography. The graphitization in high carbon steels is promoted with 0.003~0.005%B addition. But the graphitization in steels which has no boron takes long holding time at $680{\sim}720^{\circ}C$. The hardness of quenched steel containing 0.003%B is higher than that of 0.005%B added steel due to complete dissolution of fine graphites into the austenite. The 0.003%B added high carbon steel graphitized at $680^{\circ}C$ for 25hr is useful steel for the agricultural implements and automobile parts which needed a good formability and high hardness.

• Smart Structures and Systems
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• v.9 no.3
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• pp.231-251
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• 2012

The stochastic optimal control for a piezoelectric spherically symmetric shell subjected to stochastic boundary perturbations is constructed, analyzed and evaluated. The stochastic optimal control problem on the boundary stress output reduction of the piezoelectric shell subjected to stochastic boundary displacement perturbations is presented. The electric potential integral as a function of displacement is obtained to convert the differential equations for the piezoelectric shell with electrical and mechanical coupling into the equation only for displacement. The displacement transformation is constructed to convert the stochastic boundary conditions into homogeneous ones, and the transformed displacement is expanded in space to convert further the partial differential equation for displacement into ordinary differential equations by using the Galerkin method. Then the stochastic optimal control problem of the piezoelectric shell in partial differential equations is transformed into that of the multi-degree-of-freedom system. The optimal control law for electric potential is determined according to the stochastic dynamical programming principle. The frequency-response function matrix, power spectral density matrix and correlation function matrix of the controlled system response are derived based on the theory of random vibration. The expressions of mean-square stress, displacement and electric potential of the controlled piezoelectric shell are finally obtained to evaluate the control effectiveness. Numerical results are given to illustrate the high relative reduction in the root-mean-square boundary stress of the piezoelectric shell subjected to stochastic boundary displacement perturbations by the optimal electric potential control.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1229-1236
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• 2012

Our previous studies showed that kisspeptin-10 (Kp-10) injected in vivo can markedly increase lipid anabolism in liver of quails. In order to investigate the direct effect of Kp-10 on lipid metabolism of hepatocytes in birds, cells were separated from embryos livers and cultured in vitro with 0, 100 and 1,000 nM Kp-10, respectively. The results showed that after 24 h treatment, cells viability was not affected by 100 nM Kp-10, but showed a mild decrease with 1,000 nM Kp-10 compared to the control cells. Based on the results of the cell viability, 100 nM dosage of Kp-10 was selected for the further study and analysis. Compared with control cells, total cholesterol (Tch) contents in 100 nM treated cells were increased by 51.23%, but did not reach statistical significance, while the level of triglyceride (TG), high density of lipoprotein-cholesterol (HDL-C) and low density of lipoprotein-cholesterol (LDL-C) were significantly increased. Real-time PCR results showed that ApoVLDL-II mRNA expression had a tendency to increase, genes including sterol regulatory element-binding protein-1 (SREBP-1), acetyl coenzyme A carboxylase ${\alpha}$ ($ACC{\alpha}$), carnitine palmitoyltransferase 1 (CPT1), 3-hydroxyl-3-methylglutaryl-coenzyme A reductases (HMGCR) and stearyl coenzyme A dehydrogenase-1 (SCD1) mRNA in hepatocytes were significantly down-regulated by 100 nM Kp-10. However, contrary to its gene expression, SREBP-1 protein expression was significantly up-regulated by 100 nM Kp-10. Some of the significant correlations in mRNA expression were found between genes encoding hepatic factors or enzymes involved in lipid metabolism in liver of birds. These results indicate that Kp-10 stimulates lipid synthesis directly in primary cultured hepatocytes of chickens.

• Smart Structures and Systems
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• v.15 no.2
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• pp.447-468
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• 2015

Modal identification of civil engineering structures based on ambient vibration measurement has been widely investigated in the past decades, and a variety of output-only operational modal identification methods have been proposed. However, vibration modes, even fundamental low-order modes, are not always identifiable for large-scale structures under ambient vibration excitation. The identifiability of vibration modes, deficiency in modal identification, and criteria to evaluate robustness of the identified modes when applying output-only modal identification techniques to ambient vibration responses were scarcely studied. In this study, the mode identifiability of the cable-stayed Ting Kau Bridge using ambient vibration measurements and the influence of the excitation intensity on the deficiency and robustness in modal identification are investigated with long-term monitoring data of acceleration responses acquired from the bridge under different excitation conditions. It is observed that a few low-order modes, including the second global mode, are not identifiable by common output-only modal identification algorithms under normal ambient excitations due to traffic and monsoon. The deficient modes can be activated and identified only when the excitation intensity attains a certain level (e.g., during strong typhoons). The reason why a few low-order modes fail to be reliably identified under weak ambient vibration excitations and the relation between the mode identifiability and the excitation intensity are addressed through comparing the frequency-domain responses under normal ambient vibration excitations and under typhoon excitations and analyzing the wind speeds corresponding to different response data samples used in modal identification. The threshold value of wind speed (generalized excitation intensity) that makes the deficient modes identifiable is determined.

• Transactions on Electrical and Electronic Materials
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• v.16 no.6
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• pp.342-345
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• 2015

The n -type Hf_0.25Zr_0.25Ti_0.5NiSn_0.998Sb_0.002 Half-Heusler (HH) alloy composition was prepared by using the induction melting method in addition to the mechanical grinding, annealing, and spark plasma sintering processes. Analysis of X-ray diffraction (XRD) results indicated the formation of a pure phase HH structured compound. The electrical and thermal properties at temperatures ranging from room temperature to 718 K were investigated. The electrical conductivity increased with increasing temperatures and demonstrated nondegenerate semiconducting behavior, and a large reduction in the thermal conductivity to the value of 2.5 W/mK at room temperature was observed. With the power factor and thermal conductivity, the dimensionless figure of merit was increased with temperature and measured at 0.94 at 718 K for the compound synthesized by the induction melting process.

• Korean Journal of Plant Resources
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• v.16 no.1
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• pp.25-33
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• 2003

Different ages of the ginsengs were collected from the three soil areas, such as granite, phyllite and shale of Keumsan, with their field soils. Of the soils, phyllite and shale areas are high in the Ni, Cr, Co, Sc, V, As, Cu and Zn contents while the granite areas are low in the W, Pb, Th, U, Sn and Be contents. In the correlation coefficient of the soils, positive and negative relationships of the elements are mainly high in the shale and low in the granite area. Comparing between 2- and 3- year ginsengs, 2-year ginsengs are mainly high in most elements, especially for the granite and phyllite areas. In the regional comparisons among the same ages, the granite areas are mainly low and high in the shale area for the most of the elements. Comparisons among the parts of ginsengs suggest high contents in the most of the elements at the upper parts. In the comparisons between the top soils and ginseng compositions, top soils are mainly high and show similar increase/decrease trends between them. Following the transitional element contents, the granite area is best for the ginseng cultivation while , among the three areas, the shale area is worst.