• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.761-769
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• 2011

The objective of this study was to investigate the physicochemical properties of Korean traditional soy sauces made with soybeans sown in different producing regions(Hadong, Paju) and in different seeding periods(late-May, mid-June, late-June). The total acidity, salt content, chromaticity, browning, amino nitrogen content and the reducing sugar content of the soy sauce samples were compared. It was found that the total acidity level and the amino nitrogen contents were significantly lower in the soy sauce made with mid-June soybeans, and that these properties increased as the sauce aged. Salt content increased with the aging period regardless of the region of production. The reducing sugar content of Paju soy sauce was the highest in late -June, and for the Hadong region, highest in late-May. The sauce made with Hadong soy beans showed an increase in reducing sugar content positively correlated with the aging period. Reducing sugar content in the samples of Paju soy sauce decreased up to 60 days of aging, but increased after this point. In Paju soy sauce, the brightness(L value) was significantly higher in mid-June, and the Hadong variant it was higher in late -May. The yellowness(b value) at the beginning of the aging process was high in late -June for Hadong soy sauce, but overall it was higher in the mid-June period. The more matured soy sauce samples were darker and showed both higher a and b values. The browning was the lowest in the mid -June regardless of the regions and it increased with the aging period regardless of the production regions. The salt, amino nitrogen contents, browning and yellowness showed significant correlations among the samples. In conclusion, the seeding period of soy beans may affect the characteristics of produced soy sauce alongside the aging conditions.

• Journal of the Korean Ceramic Society
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• v.21 no.1
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• pp.11-18
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• 1984

$eta$-Sialon synthesis was investigated via the simultaneous reduction and nitridation of Hadong Pink Kaolin using the graphite as a reducing agent at 135$0^{\circ}C$ under 80% $N_2-20%H_2$ atmosphere. When Hadong Pink Kaolin-graphite-silicon nitride seed(molar ratio ; $SiO_2:C:Si_3N_4$=1;3.5:0.05) mixture was heated at 135$0^{\circ}C$ for as long as 20h in 80%$N_2-20%H_2$ atmosphere a homogeneous $eta$-Sialon$(Si_{3.5}Al_{2.5}O_{2.5}N_{2.5})$ was mainly formed together with a small amount of $\alpha$-$Si_3N_4$.

• Journal of the Mineralogical Society of Korea
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• v.2 no.1
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• pp.11-17
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• 1989

The kaolin deposits in Hadong-Sancheong area, have been formed by supergene weathering of anorthositic rocks including anorthosite, leucogabbro, and gabbro. Kaolin consists chiefly of halloysite(10$\AA$) and kaolinite with other minerals such as illite, vermiculite, plagioclase, hornblende, quartz amorphous materials(allophane and siica), goethite, and hematite. Goethite and hematite are the major coloring agents of the reddish brown and other colored kaolins. Other common accessory minerals are magnetite, ilmentite, anatase, gibbsite, I/S, C/V, chlorite, lithiophorite, and birnessite. Paragonite, dravite, laumontite, clinozoisite, muscovite, scolecite, stellerite are locally found. Al substitution of Fe in goethite and hematite decreases from the surface zone toward the deeper zone. The kaolin deposits show three horizontal zoning; the upper reddish brown, middle pink, and lower white zones. All the zones are characterized by somewhat different mineralogy. The factors for the formation of kaolin deposits in Hadong-Sancheong area are 1) the presence of anorthositic rocks, 2) the low flat or gentle topography, 3) the favorable climate, and 4) the long-continued preservation of kaolins with-out erosion.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.56-61
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• 1999

The Simulation of Boiler System for Hadong Fossil power plant has been made by Korea Electric Power Research Institute (KERRI) in an attempt to develop Windown NT based full scope replica simulator for Hadong Fossil power plant, 500MWe once-through boiler. In the project KERRI developed Once Through, Super Critical type Boiler System, the core part of the Simulation and integrated the system with other process systems such as BOP System, and AUX System. This paper is to introduce the basic concept of the simulation for the Boiler System. It will also introduce PRO-TRAX System, for used as a modeling tool.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.204-204
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• 2000

This paper describes the development of training simulator for Hadong fossil Power Plant. The simulator was developed to train operator, test new control Logic and evaluate alternative operating procedure for expert engineer of control system. The most control logics such as Siemens TELEPERM ME and GE Mark V are translated directly from microprocessors. Those HMI are also directly emulated. The simulation was performed by ProTRAX modeling software. The paper discusses the configuration of simulator and the simulation results of 30%, 50%, 75% and 100% normal rate load test.

• Journal of the Korean Ceramic Society
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• v.15 no.1
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• pp.21-27
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• 1978

Hadong Kaolin (Halloysite) was granulated cylindrically and treated with 1N aqueous sodium hydroxide solution for 6-48 hrs at 60-10$0^{\circ}C$. The crystalling structure of surface of the products was studied by X-ray powder diffraction method. The reaction rate of halloysite to sodium A zeolite showed a gradual decrease from surface to inner layer. At the surface layer, the reaction mechanism was observed as first order consecutive reaction as follows: halloysitelongrightarrowamorphous aluminosilicatelongrightarrowsodium A zeolitelongrightarrowhydroxysodalite By applying the above reaction mechanism, the rate constants and activation energies was measured.

• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.98-104
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• 1999

The characteristics of the populations of shortnecked clam (Ruditapes philipinarum) originated from three different seed-production sites, Hadong, Kochang and Ulsan along the coast of Korea, were analysed by the morphological differences and the random amplified polymorphic DNA (RAPD) profiles. The morphology of the shell and survival rate for each population were also investigated 13-months after transplantation to a farming site in Shinsung. The morphology of the populations from Hadong and Kochang showed significant differences (P<0.05), but one year after transplantation to Shinsung, the morphology of these three populations was no longer significantly different (P>0.05). The template DNA for RAPD was efficiently extracted from the digestive diverticula of the clams. Up to 13 of amplified fragments were detected using arbitrary primers. Within the species of R. philipinarum, the genetic similarities ranged from 0.196 to 0.259. The populations from Hadong and Ulsan showed the highest similarity. The survival rates of the populations from Hadong $(69.4\%)$ and Ulsan $(63.8\%)$ were higher than that from Kochang $(41.7\%)$ 13-months after transplantation. From the RAPD analysis, it could be used as one of the primary criterion in determining which shellfish populations among various seed-production sites tend to be genetically similar and more adaptable and transplantable to a farming site.

• Journal of the Korean Wood Science and Technology
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• v.39 no.4
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• pp.370-380
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• 2011

This study was carried out to investigate the properties of soils in the sampling green tea farms and the chemical constituents of the green tea leaves at the 3 harvest stages (Ujeon ${\rightarrow}$ Sejag ${\rightarrow}$ Jungjag). The results as follows; The properties of the soils were sandy loam, loam, well drained and fertile-rich in phosphoric acids in general. The contents of chlorophyll, tannin, vitamin-c and total catechin were increased as harvest periods getting late but the contents of total nitrogen, free amino acids, theanine, caffeine were decreased on the reverse. The inorganic constituents Mg, Ca and Mn were increased as harvest periods getting late but the Na, K, B contents were decreased on the reverse. The contents of the total nitrogen, chlorophyll, total free amino acid, theanine, caffeine and total catechin and Na, Mg, Ca, B and Se were insignificant differences between Ujeon and Sejag.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.49-61
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• 2012

This study was carried out to investigate the chemical composition and the inorganic constituents of the green tea at the 3 picking periods (Ujeon, Sejag, Jungjag) in Hadong. The results as follows ; The contents of chlorophyll, tannin, vitamin-c and total catechin were increased as picking periods increased but the contents of total nitrogen, total free amino acids, theanine and caffeine were decreased on the reverse. The inorganic constituents Mg, Ca and Mn were increased as picking periods getting late but the Na, K, B contents were decreased on the reverse. The contents of the total nitrogen, chlorophyll, total free amino acid, theanine, caffeine and total catechin and Na, Mg, Ca, B and Se were insignificant differences between Ujeon and Sejag.

• Economic and Environmental Geology
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• v.52 no.2
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• pp.141-158
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• 2019

The quantity of heavy metals in agricultural surface and subsurface soils around coal-fired power plants located in Samcheonpo and Hadong, Gyeongnam Province, were determined. The analytical results for 48 and 61 soils in Samcheonpo and Hadong, respectively, showed that the concentrations of Cu, Hg, Ni, Pb, and Zn were below the warning criteria regulated by Korean Soil Conservation Act; however, Cd in 38 and 13 soils in Samcheonpo and Hadong, respectively, exceeded the criterion. As a result of calculation of the geoaccumulation index and the enrichment factor, the soils were extremely contaminated with Cd and such high loading of Cd to the soils was due to anthropogenic source(s). Sequential extraction of the soils, however, showed that heavy metals including Cd existed as hardly extractable phases, which represented a low bioavailability of the heavy metals. Our results indicated that Cd contamination around the coal-fired power plants was due to artificial source(s) and may unlikely deteriorate nearby ecosystems.