• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.1
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• pp.39-44
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• 2005

A sheet type of green body was made with the mixture of 60 wt% red clay, 20 wt% fly ash, and 20 wt% stone sludge. Indentations were made on the surfaces of sheets to investigate fracture rate of 1 to 5 mm artificial light-weight aggregates by various drying, breaking, and forming methods. Drying methods of green bodies were natural, electric oven, microwave, and fast drying by torch. Breaking methods of green bodies were ballmill Ⅰ, ballmill Ⅱ, free dropping in the box, and mechanical breaking with roller mill. The depth and width of indent on the surface of the sheet were varied and the thickness of green bodies was also changed to investigate effects of indentation on fracture rates. The highest fracture rate of 42 % among the various drying methods was obtained by microwave drying for 210 sec and the highest fracture rate of 65 % among the various breaking method was obtained by ballmill Ⅱ method. In forming method, an yield of larger aggregates than Ф = 5 mm decreased and that of smaller aggregates than Ф = 5 mm in creased with increasing depth of indentation (only in 3 mm thick green body)and with increasing thickness of green body. The size of aggregates was most homogeneous (by judging from the measurement of aspect ratio of 1 to 5 mm aggregates.) when 3 mm thick green body was rapidly dried by torch and was broken by ballmill Ⅱ method.

• Journal of Wetlands Research
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• v.13 no.1
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• pp.95-104
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• 2011

This study was implemented to select the suitable site for Palustrine Wetland at habitat restoration for Oriental stork, red species and top-level predator in ecosystem. The evaluation items was fitted by review the antecedent studies on the suitable site selection model and evaluation items of wetland. The study sites were setted in $5,884,800m^2$ area including Yesan-gun Dae-ree, in which Oriental stork' park will be located, through DEM(Digital Elevation Model) watershed analysis. The thematic map by valuation items with secure of water resource, soil, topography, distance between roads, houses, etc., land using, wildlife corridor, and type of water resource was prepared using GIS program. The sites with high evaluation score were selected as suitable creation sites for wetland through overlapping those maps. Total 8 sites with over 18 point were selected. The characteristics of selected sites show that the soil are consisted of clay, the connectivity is valued high with surface water, the slope are gentle, and the connectivity is good with surroundings ecosystem. The result of water quality analysis, which was implement to survey available water resources and develop the solution of problem of water environment, showed that water quality at Salmok reservoir and Bogang reservoir is generally good, but the water quality at stagnant water body rising out from groundwater is not good. This study has limit to select the suitable sites of wetland only by analyzing physiotherapy environment in study area. Hereafter, the study is need to examine closely enhancement effects of biological diversity through investigation of biotic environment.

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.173-179
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• 2017

This study investigated the effect of bamboo salt (BS) on body gain, feed intake, meat composition, and blood characteristics of broiler chicks. BS was processed by roasting salt at $1,200{\sim}1,300^{\circ}C$ in a bamboo container, with the open end plugged with red clay. In total, 120 broiler chicks were assigned to four treatments. Each treatment was triplicated, with 10 chicks in each treatment group. The supplementation levels of the three BS-treated feeds were 0.1, 0.2, and 0.3%. Body weight gain slightly increased in broiler chicks fed diets supplemented with BS compared to that of the control during the overall test period. However, no significant differences were observed among treatments. Feed intake was also not significantly different among treatments. Feed efficiency was significantly (p<0.05) improved in broiler chicks fed diets supplemented with BS compared to that of the control. Body weight gain was more positively affected by the dietary BS supplement at the beginning of the experimental period than toward the end. Water intake was positively correlated with the dietary 0.3% BS level (p<0.05). Breast meat composition and cholesterol levels were also not affected by BS supplementation. The total protein, albumin, glutamic oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), and total cholesterol levels in the blood were not significantly different among treatments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.605-610
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• 2001

To suppress the gas forming caused by some yeast in the pack of traditional kochujang prepared at Sunchang area, which is the most severe problem during distribution of commercial products, mustard or horseradish powder as natural preservatives was mixed to the ingredients of kochujang and left for fermentation in clay pot as commercial scale for 180 day. The composition changes including quality and gas formaing in the kochujang containing those additives were monitored physicochemically and organoleptically. The fermented kochujang containing those additives were monitored physicohemically and organoleptically. The fermented kochujang containing 0.6% of horseradish showed lower organic acid content than that of the control but amino type nitrogen content, which is one of the important quality reference of kochujang, was higher in the one containing 0.6% natural preservatives. No color changed in the kochujang containing mustard but L and a value were increased in the kochujang containing horseradish. No difference of free reducing sugars was showed by the addition of those natural preservatives and the addition of 0.6% horseradish to kochujang had completely stopped gas forming during fermentation. The overall quality of the kochujang containing 0.6% horseradish was superior than that of the other treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.98-104
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• 2001

Cultivation area of the plastic film-house has been continuously increased with the increase of consumers' income. Intensive land use without fallowing or crop rotation caused severe problem such as salt accumulation in soils and in turn retarded growth and low productivity. This study was carried out to solve them derived from longterm intensive farming practices. Seven farmers who are practicing plastic film-house cultivation were recommended for case study by municipal government and selected for their excellency of cultivation and soil management. The cultivation periods of these systems were in the range of 5 to 40 years in the regions mainly located in alluvial soil cultivated with cucumber, tomato and red pepper. The soils texture of the excellent farmers' fields were silt loam or sandy loam, ranged from 7 to 15 percents of clay contents. Soil bulk density, depth of plowing layer and soil aggregates contents of the farmers' soils were 0.89, 23.1 cm, 61.6% whereas those in neighboring soils were 1.10, 17.8 cm, 54.2 %, respectively. And pH, OM and $NO_3-N$ of the farmers' soils also were better than those of neighboring soils. There was no difference in population densities of nematode between the good farmers' and neighboring soils, but actinomyces and Fusarium densities of recommended farmers' soils were better than neighboring soils. The major farming practices by the good farmers were characterized by deep plowing with flooding, amendment of crude organic matter, and reduction of chemical fertilizer application before transplanting, and also drip irrigation and liquid manure application after planting. They also conducted solar sterilization with or without flooding, removal of plastic films during rainy days and culturing rice or corn as rotation crops to avoid the problems mentioned above.

• Journal of Bio-Environment Control
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• v.10 no.1
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• pp.36-41
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• 2001

This experiment was carried out to investigate temperature distribution in the double layer plastic greenhouse and chilling injury to watermelons grown during a cold season. Temperatures on eastern and western sides were about 6.2% and 14.7%, respectively, lower than that of central section in a south-north oriented greenhouse. Daily mean temperature in the northern part was about 1-2$^{\circ}C$ higher than that in the southern part of the greenhouse. In terms of vertical temperature distribution inside the greenhouse, temperature at ground surface was approximately 1$^{\circ}C$ lower during the day and 0.5$^{\circ}C$ higher during the night than that in the upper part, 2m from the ground surface. Leaf mould medium kept higher ground temperatures as compared to sandy soil, red clay soil, and in the northern and southern sides as compared to the central part of the greenhouse. A symptom of chilling injury on leaves was upward curling, followed by chlorosis and necrosis. A severe symptom of chilling injury to plants was the breakdown of vascular bundles. Root growth was more susceptible than stem or leaf growth to low temperatures. At 3$0^{\circ}C$, main and lateral roots grew vigorously, while lateral root growth was inhibited at 22$^{\circ}C$ and root growth was stopped at 14$^{\circ}C$ and 6$^{\circ}C$. Small and puffy fruits with dark green surface were produced at low temperatures. In cold season cultivation of watermelons, it is suggested that plants be transplanted in the central part and train to sides of the greenhouse in order to reduced chilling injuries.

• Korean Journal of Heritage: History & Science
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• v.45 no.3
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• pp.194-211
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• 2012

Pung-nap mudcastle has brought wide attention to archaeologists since scientific studies were carried out on the various types of building sites and excavated potteries related to A period of Baekje Kindom when it sat Hansung as the capital. It is identified that clay from Ra-No.19 site of Pung-Nap mudcastle has different from compositions that of residential soil. From archaeological point of view, it is believed that the the soil was a source material for potteries due to the appropriate viscosity and inclusions. Mineralogical and geochemical studies show that the compositions between the source material and randomly chosen two potteries from the same site are similar. Behavior pattern classification of major, trace and rare elements provides also very similar result. Artificial specimen has been made at different temperature in order to estimate firing temperature of the potteries by means of various kinds of instrumental application. As a result of the study, it is believed that the firing temperature of the red and brown pottery was $550{\sim}600^{\circ}C$ and $900{\sim}1,000^{\circ}C$ respectively.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.150-171
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• 2013

The most important part of conservation treatment of murals is to preserve them against the risk of a damage by injecting fixative into them when the painting loses its cohesion or powderization of pigments occurred due to occurrence of cracks inside the painting layer. However, studies on the stability of fixative used for painting layers of murals are still insufficient. This study manufactured a mural as a specimen and colored it with four kinds of pigments including oyster shell white, cinnabar, malachite and red clay and applied four kinds of fixative, including, Paraloid $B-72^{(R)}$, Caparol-$binder^{(R)}$, glue and Hydoxypropyl $cellulose^{(R)}$. artificially generated environmental changes in temperature, humidity and ultraviolet rays which may occur after the completion of conservation treatment. Then the changes in physical properties were observed in multifaceted ways such as color stability, contact angle, brilliance, adhesive strength and surface. As a result, this study found that ultraviolet rays and hot?humid environment have a large impact on color stability causing changes in brightness and chroma of all painting layers where the fixative were applied, except for oyster shell white and are considered the main factors of decomposition by accelerating the aging process of fixatives applied. In comparison to the synthetic resins that were also tested in this study, the traditional glue showed satisfactory results in terms of color stability and influence preservation and the hydrophile property. As it showed exceptionally outstanding adhesive strength in all painting layers in the aspect of adhesive strength, it is considered to be highly stabile for the fixation treatment of painting layers of mural.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.45-45
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• 2019

This experiment was carried out using artificial clay and LED in the plastic film house (irradiation time: 08:00~18:00/day). Seedlings (n = 63 per $3.3m^2$) of ginseng was planted on May 17, 2018. LED was combined with red and blue light in a 3:1 ratio and irradiated with different light intensity. The average air temperature from April to September was $12.3^{\circ}C$ $-26.0^{\circ}C$ and it was the the highest at $26.0^{\circ}C$ in August. The test area where fluorescent lamp was irradiated tended to be somewhat higher than the LED irradiation area. The chemical properties of the test soil are as follows. pH levels was 5.3~5.5, EC levels 0.45~0.52 dS/m and OM levels 33~37%. The total nitrogen content was 0.35~0.47% and the available $P_2O_5$ contents was 13.7~16.0 mg/kg, which was lower than the suitable level of 70~200 mg/kg. Exchangeable cations K and Mg contents were within acceptable ranges, but the Ca contents was $28{\sim}38cmol^+/kg$ levels higher than the permissible level ($2{\sim}6cmol^+/kg$). Germination of ginseng leaves took 8~9 days and the overall germination rate was 70~75%. The photometric characteristics of LED light intensity are as follows. The greater the light intensity, the higher the PAR (Photosynthetic Action Radiation) value, illuminance and solar irradiation. Photosynthetic rate was also increased with higher light intensity was investigated at $1.7{\sim}3.2{\mu}mol\;CO_2/m^2/s$. Leaf temperature ($23.7{\sim}24.8^{\circ}C$) by light intensity was the same trend. The growth of aerial parts (plant height etc.) were generally excellent when irradiated with 3 times the light intensity, the growth of the ginseng aerial parts were excellent as follows. The plant height was 42.6 cm, stem length was 25.2 cm, leaf length was 9.6 cm and stem diameter was 5.0 mm. The growth of underground part (root length etc.) was the same, and the root length was 24.4 cm, the tap root length was 6.0 cm, diameter of taproot was 18.2 mm and the fresh root weight was 17.2 g. There were no disease incidence such as Alternaria blight, Gray mold and Anthracnose. Disease of Damping off occurred 2.2~3.6% and incidence ratio of rusty root ginseng was 14.6~20.7%. Leaf discoloration rate was 13.7~48.9% and increased with increasing light intensity. Ginsenoside content of ginseng by light intensity is under analysis.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.2
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• pp.128-140
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• 1982

The distribution and practical classification of sandy paddy soils, which have the most extensive acreage among low productive paddy soils in Korea and have distinctive improvement effects, were studied to propose a tentative new classification system of sandy textured paddy soils as a means of improving the "Paddy Soil Type Classification" scheme used. The results are summarized as follows; 1. The potential productivity of sandy textured paddy soils was about 86% of normal paddy and the coefficient of variation was relatively high indicating that the properties of soils included were not sufficiently homogeneous. 2. As the poorly drained and halomorphic (> 16 mmhos/cm of E.C. at $25^{\circ}C$) sandy soils are not included in the "Sandy Soil" type according to the criteria of "Soil Type Classification", the recommendation of "adding clay earth" become complicated, and the soil type have to change when the salts washed away or due to ground water table fluctuations. 3. Coarse textured soils were entirely included in the "Sandy Soils" in the tentative criteria of sandy soil classification proposed, and the sandy soils were subdivided into 4 subtypes that is "Oxidized leaching sandy paddy", Red-ox. intergrading sandy paddy", "Reduced accumulating sandy paddy" and "Reduced halomorphic sandy paddy". The system of sandy soil classification proposed were consisted of following categories; Type (Sandy paddy)-Sub-type (4)-Texture family (5)-Soil series (48). 4. The variation of productivities according to the proposed scheme was more homogenized than that of the present device. 5. The total extent of sandy paddy soils was 409, 902 ha (32.3% of total paddy) according to the present classification system, but the extent reached 492,983 ha (38.9%) by the proposed system. The provinces of Gyeong-gi (88.923ha), Jeon-bug (69.717 ha), Gyeong-bug (55.390 ha) have extensive acreage of sandy paddy soils, and the provinces that had high ratio of sandy paddy soils were Gang-weon (58.9%), Gyeong-gi (50.5%), Chung-bug (48.5%), Jeon-bug (41.0%) etc. The ratio was increased by the proposed scheme, e.g. 71.4% in the case of Gang-weon prov. 6. According to the suitability group of paddy soils, the sandy soils mostly belong to 3 class (69.1%) and 4 class (29.2%). Coarse loamy textural family (59.2%) and coarse silty (16.1 %) soils were dominantly distributed. 7. The "Red-ox. intergrading subtype" of sandy paddy pertinent to 49.6% (245,012 ha) while the "Oxidized leaching sub-type" reaches to 33.5% (64,890 ha) and the remained 16.9% (83,081ha) belong to "Reduced accumulating sub-type (14.0%) and "Reduced halomorphic sub-type (2.9%)" according to the proposed scheme.