• Journal of the Korean Society of Food Science and Nutrition
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• v.2 no.1
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• pp.1-21
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• 1973

The muscle of abalone, Notohaliotis discus (REEVE), and top-shell, Turbo cornutus Solander, were examined for protein composition. Then paramyosins which are known as one of the important structural protein of the muscle fibrils were isolated from the both muscle and their physico-chemical properties such as solubility, salting-out behaviour, intrinsic viscosity, ATPase activity, etc. involving amino acid composition and N-terminal amino acid residues were investigated to elucidate phylogenie characteristics more intensively from the viewpoint of comparative biochemistry. The analysis of protein composition resulted in the following estimations: abalone muscle; water-soluble protein of 22 %, salt-soluble protein, 34%, alkali-soluble protein, 20%, and stroma protein, 24%, and top-shell muscle; water-soluble protein of 16%, salt-soluble protein, 30%, alkali-soluble protein, 29%, and stroma protein, 25%, respectively. It is demonstrated in sedimentation analysis that paramyosin and myosin-actomyosin account for approximately 65% and 35% of the salt-soluble protein of abalone, and that the composition of both sediments in top-shell was approximately 70% and 30%, respectively. The ultracentrifugally homogenous paramyosins isolated essentially according to Bailey's ethanol-dried method from both of the muscle showed a $S^{\circ}_{20,w}$ of 3. 14s for abalone and a $S^{\circ}_{20,w}$ of 3.50s for top-shell. The both paramyosins were commonly rich in arginine, aspartic acid, and glutamic acid, while scarcely contained proline and tryptophan, in rough accord with the other paramyosins thus far reported. It is clear that these gastropod paramyosins showed of having the characteristic N-terminal amino acid residues such as N-aspartic acid, N-valine, N-serine, and N-threonine in common. The abalone paramyosin completely salted in with KCl beyond $0.35{\mu}$ and the top-shell paramyosin beyond $0.30{\mu}$. The abalone paramyosin was salted-out between 18% and 30% saturation of ammonium sulphate and the top-shell paramyosin between 22% and 29% saturation. The intrinsic viscosities at abalone and top-shell paramyosins at $25^{\circ}C$ were estimated respectively to be 3.1 dl/g and 2.6 dl/g showing somewhat higher than the values for some other paramyosins from lamellibranchs. In regard with the ATPase activity, the para myosin specimens did not exhibit any significant activity over through the pH conditions of 5 to 9.5. irrespective of the presence of $Ca^{++}$ or $Mg^{++}$. So was the case with the abalone paramyosin prepared by a slightly modified Bailey's wet-extraction method.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.1
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• pp.29-35
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• 1999

Soil structure and organic matter have been known to strongly affect water flow and solute transport, yet little information is available concerning soil hydraulic properties related to soil physical and chemical properties in the forest site. The purpose of this study was to quantify the spatial variability and spatial correlation of the measured parameter values from the plots established with the rainfall simulator on Japanese larch(Larix leptolepis) dominated site in Kwangju. Kyunggi-Do. Measurement of soil water flux and retention were made with the inherent soil texture, soil structure, and organic matter. The method was based on the observation that when water was applied at a constant rate to the soil surface on each plot. The method was simple to apply and consists of following steps: (i) Wet the soil from a rainfall simulator with several known discharge rates on a relatively leveled soil surface with and without organic matter. (ii) Once the borders of the ponded zone were steady, saturated hydraulic conductivity( $K_{s}$) and the matric flux function(F) was evaluated from a regression of flux vs. the reciprocal of the ponded area. A conductivity of the form $K_{i+}$$_1$ $_{c}$= $K_{i}$( $_{c}$) [1-d /dz] where flux continuity implies. For this, continuity of matric potential at the interface at all times are as follows: $_1$( $Z_{c}$) = $_2$( $Z_{c}$) = $_{c}$ for steady state intake from water ponded on the soil surface. Results of this investigation showed the importance of understanding spatial variability in wide differences of water retention and saturated hydraulic conductivity with respect to pore geometry and organic matter contents which influenced the water flux throughout the soil profile.l profile.ile.

• The Journal of Korean Academy of Prosthodontics
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• v.19 no.1
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• pp.17-27
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• 1981

This study was conducted to determine the chemical composition and the mechanical properties of four commercially available low gold-based crown and bridge alloy produced in Korea. Four dental casting gold-silver-palladium alloys, i.e., A, B, C and D (code of alloys) were selected for the evaluation of chemical composition, ultimate tensile strength, elongation. values and Vickers hardness. The chemical composition of test specimens was analyzed by both emission spectrography and wet gravitation method with a 1.5gm of low gold ingot. The tensile properties and Vickers hardness was determined with cast specimens treated in following three conditions; as-cast, softening heat treatment and hardening heat treatment. The tensile testing bars were cast in accordance with the model designed by Gettleman and Harrison (1969) which was modified from the A. D. A. Specification No. 14 for dental chromium-cobalt casting alloy. Nine tensile test specimens were made from a split silicone mold for each of the test alloys to the size of 2.5mm in diameter and a gauge length of 10mm. All four alloys were handled in accordance with conventional methods used in Type III gold alloys. Ultimate tensile strength and elongation were measured on an Instron Universal Tensile Testing Machine (Model 1125, Japan) operated at a crosshead rate of 0.1cm/min. Elongation values were measured using Digital Measuring Microscope (MS-152, FUSOH, Japan). Vickers hardness was determined with a Vickers Hardness Tester (Model VKH-l, Japan) at a 1.0kg load on a mounted tensile test specimen. The following results were obtained from this study; 1. All tested alloys were composed of Au, Ag, Pd, Cu, Zn and Fe in common. The composition rate of gold for all four alloys was found in the range of $42{\sim}47$ weight % as shown below. Alloy A; Au 45%, Ag 40.2%, Pd 5.76%, others 9.04%. Alloy B; Au 47.1%, Ag 29.03%, Pd 6.98%, others 16.92%. Alloy C; Au 45%, .Ag 26.9%, Pd 6.83%, others 21.07%. Alloy D; Au 41.8%, Ag 34.4%, Pd 6.95%, others 16.85%. 3. The ultimate tensile strength of the four alloys was in the range of $31{\sim}82kg/mm^2$. The test results were shown in the below order from the highest value; As-cast condition; D, B, C, A. Softening heat treament; B, C, D, A. Hardening heat treatment; D, B, C, A. 4. The test :results of the elongation rate for each alloy were in the range of $0.5{\sim}18%$. The test results were shown in the below order from the highest value; As-cast condition; A, D, B, C. Softening heat treatment; A, C, D, B. Hardening heat treatment; C, D, B, A. 5. Vickers hardness for each of the four alloys was in the range of $120{\sim}230$. The test results were shown in the below order from the highest value; As-cast condition; C, B, D, A Softening heat treatment; D, B, C, A. Hardening heat treatment; D, A, C, B. 6. There were no differences in the physical properties between as-cast condition and softening heat treatment.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.1
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• pp.9-13
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• 2018

In this work, we investigated the variation of optical characteristics with the thickness of bulk GaN grown by hydride vapor phase epitaxy(HVPE) to evaluate applicability as GaN substrates in fabrication of high-brightness optical devices and high-power devices. We fabricated 2-inch GaN substrates by using HVPE method of various thickness (0.4, 0.9, 1.5 mm) and characterized the optical property with the variation of defect density and the residual stress using chemical wet etching, Raman spectroscopy and photoluminescence. As a result, we confirmed the correlation of optical properties with GaN crystal thickness and applicability of high performance optical devices via fabrication of homoepitaxial substrate.

• Journal of Environmental Science International
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• v.12 no.4
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• pp.461-467
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• 2003

This study was conducted to provide the basic information to know reasonable method f3r the removal and treatment of municipal solid wastes(MSWs). MSWs four different sources(apartment residence, commerce, office/industry) in Daegu city were collected, and bulk density, physical composition, moisture, combustible, ash, elements and heating values were investigated. The values of bulk density were at range of 0.30∼0.41ton/m$^3$. The percentages of foods, papers, vinyls/plastics, textiles, rubbers/leathers, metals and glasses/ceramics of wet muncipal solid wastes from three sources except office/industry were at range of 27.3∼46.4%, 21.2∼38.4%, 10.3∼11.9%, 3.8∼5.2%, 0.5∼1.7%, 6.9∼8.7% and 1.9∼2.6% respectively. The percentages of papers, foods, vinyls/plastics, textiles, rubbers/leathers, metals and glasses/ceramics of dry muncipal solid wastes from three sources except office/industry were at range of 21.1∼40.4%, 14.2∼30.1%, 15.2∼17.8%, 4.0∼6.0%, 0.9∼2.8%, 12.2∼14.1% and 3.1∼3.7％ respectively. The moisture contents of foods, woods, textiles and papers in wastes were at range of 65.7∼76.2%, 34.6∼50.0%, 22.2∼44.8 and 30.6∼44.4% respectively. The carbon contents of vinyls/plastics, rubbers/leathers, textiles, woods, papers and foods in wastes were at range of 75.88∼79.87%, 58.24∼70.74%, 45.23∼51.63%, 42.29∼45.58%, 40.19∼48.4% and 25.86∼36.25% respectively. The low heating values of foods, papers, woods, textiles, rubbers/leathers and vinyls/plastics by Dulong's law were at range of 178∼1,353kcal/kg, 770∼1,660kcal/kg, 995∼1,629kcal/kg, 2,133∼2,432kca1/kg, 4,200∼7,275 kcal/kg and 6,384∼8,722kcal/kg respectively, and the high heating values of them were at range of 782∼2,056 kcal/kg, 2,459∼3,314kca1/kg, 3,056∼3,592kcal/kg, 4,381∼5,087kca1/kg, 5,005∼8,066kca1/kg and 10,032∼10,739 kcal/kg respectively.

• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.245-250
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• 1977

Experiment were conducted to find out the effective drying method of citrus peel produced in Korea by varying the temperature of hot air, surface area of peels, peels from several citrus varieties and physicochemical treatment of the peel. 1. About $3{\sim}6\;days$ were required to reduce the moisture level of the peel from 70%(wet basis) to 20% at room temperature without forced convection. 2. Drying was speeded up until the temperature of hot air reached $60^{\circ}C$. Beyond that no significant increase in drying rate was observed. About 50 minutes were needed to reduce the moisture level (dry basis) to below 10% at $60^{\circ}C$ by forced convection 3. When the peel surface area was increased twice by cutting the peel into 256 fractions, the overall drying time (the time required to reduce the moisture level to 10%, dry basis) was shortened to 15 minutes from 50 mintes of the original peel. 4. No significant difference in drying rate was observed among the peels from several citrus varieties except Shaddock jabon and Citrus ponki tanaka, which dried more slowly than others. 5. Treatment of $Ca(OH)_2$ and the pressing of the peel before drying were effective in drying only when the initial moisture content was substantially higher.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.418-418
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• 2008

The electrochemical etching of silicon in HF-based solutions is known to form various types of porous structures. Porous structures are generally classified into three categories according to pore sizes: micropore (below 2 nm in size), mesopore (2 ~ 50 nm), and macropore (above 50 nm). Recently, the formation of macropores has attracted increasing interest because of their promising characteristics for an wide scope of applications such as microelectromechanical systems (MEMS), chemical sensors, biotechnology, photonic crystals, and photovoltaic application. One of the promising applications of macropores is in the field of MEMS. Anisotropic etching is essential step for fabrication of MEMS. Conventional wet etching has advantages such as low processing cost and high throughput, but it is unsuitable to fabricate high-aspect-ratio structures with vertical sidewalls due to its inherent etching characteristics along certain crystal orientations. Reactive ion dry etching is another technique of anisotropic etching. This has excellent ability to fabricate high-aspect-ratio structures with vertical sidewalls and high accuracy. However, its high processing cost is one of the bottlenecks for widely successful commercialization of MEMS. In contrast, by using electrochemical etching method together with pre-patterning by lithographic step, regular macropore arrays with very high-aspect-ratio up to 250 can be obtained. The formed macropores have very smooth surface and side, unlike deep reactive ion etching where surfaces are damaged and wavy. Especially, to make vertical microwire or nanowire arrays (aspect ratio = over 1:100) on silicon wafer with top-down photolithography, it is very difficult to fabricate them with conventional dry etching. The electrochemical etching is the most proper candidate to do it. The pillar structures are demonstrated for n-type silicon and the formation mechanism is well explained, while such a experimental results are few for p-type silicon. In this report, In order to understand the roles played by the kinds of etching solution and mask patterns in the formation of microwire arrays, we have undertaken a systematic study of the solvent effects in mixtures of HF, dimethyl sulfoxide (DMSO), iso-propanol, and mixtures of HF with water on the structure formation on monocrystalline p-type silicon with a resistivity with 10 ~ 20 $\Omega{\cdot}cm$. The different morphological results are presented according to mask patterns and etching solutions.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.239-244
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• 2000

Synthesis and high temperature phase stability of $_{1+x}$ Co$_{y}$ Mn$_{2-y}$ $O_4$(0$\leq$x$\leq$0.2,y=0,1/9,1/6) spinel, both the excess lithium and cobalt added, have been studied. The spinel was prepared by oxalate precipitation method as the wet chemical process. Oxalate derived spinel was synthesized by heating of precipitates at temperature lower than $600^{\circ}C$. As a result of the TG-DTA and XRD analysis of prepared and quenched powders, it was found that reversible phase transitions started at temperatures $T_1$, $T_2$및 $T_{2'}$. The transitions involved weight (oxygen) loss and gain during heating and cooling. The effects of Li excess and Co doping on the spinel lattice constant, phase stability and transition temperatures of the prepared powders are investigated. This study would provide important data for determining the spinel preparation process such as synthesis temperature and cooling speed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.57-63
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• 2011

Changes in food preferences and dietary habits of Korean prone to decrease consumption of the traditional energy source, rice. The exceeding condition of rice production in Korea is now not only impacting on the profit structure of farmers but also threatening food security. Although there have been several efforts to increase rice consumption rate, by developing various processed foods using rice flour, grain hardness of rice has been the most significant limiting factor. In this study, we addressed the suitability of the Namil(SA)-flo1, a mutant rice line has floury endosperm, in terms of producing rice flour by using dry-milling method, which is lower cost and more eco-friendly than other available methods such as wet-milling. Rice flour of the Namil(SA)-flo1 exhibited superior physico-chemical characteristics to any other check varieties including the wild type, Namil, in terms of distribution of granule sizes and content of damaged starch.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.61-69
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• 1995

It is hard to synthesize pure $BaTiO_3$ from $BaCO_3$ and $TiO_2$ in solid reaction for the activity of BaO and secondary phase. For this reason, the wet chemical techniques have been studied. Starting material which was used in these methods were expensive and the properties of powder which was synthesized in same defined. So, some process have been studying again to improve soild reaction method. This study which was one of those was to defin the forming mechanism of $Ba_2TiO_4$ and to control some condition of $Ba_2TiO_4$. The synthesis temperature of $BaTiO_3$ in solid reaction was near $1120^{\circ}C$. The quantity and forming temperature of $Ba_2TiO_4$ could be controlled by atmosphere heat treatment. $Ba_2TiO_4$ was related to expansion in Ba-rich region of $BaTiO_3$. $BaTiO_2O_5$ and $BaTiO_3O_7$ was reason to expand in Ti-rich region. The dielectrics of $CeAIO_3$ which was synthesized and sintered in reduction atmosphere and $BaTiO_3$ system were affected by $CeO_2$ which was formed for the decomposition of $CeAIO_3$ heat treatment in air.