• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.1
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• pp.48-55
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• 1989

This experiment was conducted to investigate the effect of animal stable manure on the dry matter yield, botanical composition, crude protein content rates, in vitro digestibility and soil characters with treatments, which were divided into cattle manure, swine manure and poultly excreta of 375 and 750kg/lOa, respectively. The results obtained were summarized as follows: 1. A comparison made on the grass yield for one year period following the termination of the experiment did not indicate any signification in the yield of dry matter difference between chemical fertilizer treatment and 750kg/10a of organic manure. 2. Botanical composition was not shown an increasing of weed or bare land in organic manure of 375 and 750kg/lOa application during the whole period of growth. 3. Crude protein content and in vitro digestibility were shown an increasing tendency according to the increase of organic manure application. 4. Crude protein yield in organic manure of 750kg/10a was not a large difference compared with chemical fertilizer treatment. 5. Soil composition of organic manure had higher than the soil composition of chemical fertilizer treatment, which was shown an increasing tendency according to the increase of organic manure. 6. Therefore, It was suggested that the effect of organic manure on dry matter yield, botanical composition was similar to chemical fertilizer treatment and soil composition of organic manure had higher organic matter, available phosphate, potassium and C.E.C than the soil composition of chemical fertilizer treatment.

• The Korean Journal of Food And Nutrition
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• v.29 no.2
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• pp.153-161
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• 2016

This study investigated the chemical composition of Solidago virga-aurea var. asiatica Nakai essential oils collected using different extraction methods. The essential oils obtained by simultaneous steam distillation extraction (SDE) and hydrodistillation extraction (HDE) methods from the aerial parts of Solidago virga-aurea var. asiatica Nakai were analyzed by GC and GC-MS. Ninety-nine volatile flavor compounds were identified in the essential oil produced from Solidago virga-aurea var. asiatica Nakai using the SDE method. These compounds were classified into eight categories in terms of chemical functionality: 26 hydrocarbons, 8 aldehydes, 36 alcohols, 7 ketones, 12 esters, 5 oxides and epixides, 4 acids, and a miscellaneous one. Spathulenol (15.66%) was the most abundant compound. Ninety-eight compounds including of 35 hydrocarbons, 6 aldehydes, 29 alcohols, 6 ketones, 10 esters, 4 oxides and epixides, 7 acids, and a miscellaneous one were identified in the essential oil from the plant using the HDE method. Hexadecanoic acid (24.74%) was the most abundant compound. The chemical composition of Solidago virga-aurea var. asiatica Nakai essential oils extracted by SDE and HDE methods are characterized by high content of sesquiterpene alcohols and acids, respectively. The extraction methods may be influenced in the chemical composition of natural plant essential oils.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.5
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• pp.207-215
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• 2010

This study was carried out for the purpose of obtaining the basic data for identifying the origin of amethyst. For this, the three dimensional shapes of inclusions contained in various amethyst were observed with Stereo Zoom microscope. The shape and chemical composition of cross section of solid inclusion and the chemical composition of evaporite were investigated by SEM-EDS. The evaporite is made from evaporating of liquid inclusion which is flowed out of amethyst sample by decompressing. Lastly, The trace mineral composition of amethyst was investigated by ICP-AES after digesting the amethyst sample with HF-$H_2SO_4$ solution.

• Macromolecular Research
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• v.16 no.3
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• pp.231-237
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• 2008

Biodegradable poly($\varepsilon$-caprolactone-co-L-lactide)-b-poly(ethylene glycol) (PCLA-b-PEG) copolymers were synthesized via solution polymerization by varying the feed composition of $\varepsilon$-caprolactone ($\varepsilon$-CL) and L-lactide (LLA) ($\varepsilon$-CL: LLA= 10:0, 7:3, 5:5, 3:7, 0: 10). The feed ratio based on weight is in accordance with the copolymer composition except for the case of $\varepsilon$-CL: LLA=3:7 (C3L7), which was verified by $^1H$-NMR. Two different approaches were used for the exceptional case, which is an extension of the reaction time or the sequential introduction of the monomer. A copolymer composition of $\varepsilon$-CL: LLA=3:7 could be obtained in either case. The chemical microstructure of PCLA-b-PEG was determined using the $^{13}C$-NMR spectra and the effect of the sequential structure on the thermal properties and crystallinity were examined. Despite the same composition ratio of the copolymer, the microstructure can differ according to the reaction conditions.

• Journal of the Korean Electrochemical Society
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• v.23 no.1
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• pp.18-23
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• 2020

Antimony telluride (Sb_xTe_y) thin films were synthesized by an electrodeposition method with a control of applied potential at room temperature. Characterization of electrical and thermoelectric properties such as conductivity, Seebeck coefficient, and power factor (P.F.) were conducted as a function of the chemical composition of the electrodeposited films. Morphology of thin films were dense and uniform and the composition was tailored from 25 to 60 at.% of the Sb content by altering the applied potential from -0.13 to -0.27 V (vs. SCE). The conductivity of the films were ranged from 2 × 10^-4 ~ 5 × 10^-1 S/cm indicating their amorphous behavior. The meaured Seebeck coefficient of films were relatively high compared to that of bulk single cyrstal Sb_xTe_y due to their low carrier concentration. The variation of the Seebeck coefficient of the films was also related to the change of chemical composition, showing the power factor of ~10 ㎼/mK².

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.561-562
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• 2006

The effect of chemical composition of the sintering atmosphere on density, microstructure and mechanical properties of Fe-3%Mn-(Cr)-(Mo)-0.3%C steels is described. Pre-alloyed Astaloy CrM and CrL, ferromanganese and graphite were used as the starting powders. Following pressing in a rigid die, compacts were sintered at 1120 and $1250^{\circ}C$ in atmospheres having different $H_2/N_2$ ratio and furnace cooled to room temperature. It has been found that the atmosphere composition has negligible effect on the as-sintered properties of the investigated materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.71-82
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• 1969

The present investigations were carried out with the purpose of making clear the fundamental features of the seasonal variations in chemical composition of the brown algae. Three species of samples, Ecklonia cava, Sargassum sagamianum and Hizikia fusiforme have been analyzed monthly for their contents of total ash, crude protein, alginic acid, mannitol, and laminarin over a year period. Three kinds of samples were collected from the same locality, situated on the southern coast of the Che-ju Island, from September 1966 to August 1967. In addition, the comparative analysis was made on fronds and stipes of the plant for their chemical composition. The results obtained are summarized as follows: 1, In general, the three species examined underwent a similar mode of seasonal variation, and no essential difference was detected among them. 2. The chemical composition of the plant exhibited a considerable difference between the species. The content of total ash in H. fusiforme was remarkably higher than those in the two other species respectively. The alginic acid content was relatively high in S. sagamianum and low in H. fusiforme. The contents of crude protein, mannitol and laminarin were appreciably high in E. cava and low in H. fusiforme in general. 3. The most outstanding feature in the seasonal variation was that, in general, the total ash, crude protein, and alginic acid contents were at a maximum in the winter months while laminarin and mannitol contents were at a minimum. The converse was true in summer. Total ash-Maximum values were observed from December to February and minimum from August till October. Crude Protein-All species exhibited maxima in January and February, and minima from August to October. Alginic acid-Maximum contents occured from January to March and minimum from September to November. Mannitol-The maximum content of mannitol was In May and lune and minimum in January, February and March. Leminerin-Maximum content was in September and October, and minimum in January and February. 4. The wide seasonal variation in chemical constitution occured in the fronds, but the stipes showed a slight seasonal variation. In the chemical composition, the stipe was high in alginic acid, low in mannitol and laminarin. The reverse was in the frond.

• Journal of Biosystems Engineering
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• v.30 no.4 s.111
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• pp.235-241
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• 2005

For better and large utilization of rice husk, the production and consumption status, differences in chemical composition and heating value due to region and variety, and thermogravimetric characteristic of rice husk were studied. In addition, the differences in chemical composition due to region and variety and the crystallization characteristic of rice husk ash were also studied. Approximately 800,000 M/T of rice husk was produced per year in Korea, which is about $18\%$ of the paddy production by weight. Noticeable varietal and regional difference pattern in chemical composition was not found among the domestic rice husk samples. Their average ash content and higher heating value were $16.4\%$ and 16,660 kJ/kg by dry basis, respectively. A relation seemed to exist between the carbon content and higher heating value. Noticeable difference pattern in chemical composition was not found among the domestic rice husk ash samples. The $SiO_2$ contents were a little low, the maximum being $92.9\%,$ and the contents of major components such as CaO, MgO, and $K_2O$ were also lower compared with foreign rice husk ash due to the deficiency of compost matters in domestic soils. Thermogravimetry study showed the thermal decomposition of rice husk started at about $250^{\circ}C,$ followed by relatively fast combustion of combustible gas until the temperature rose to $350^{\circ}C.$ After $350^{\circ}C,$ combustion of the carbon component proceeded relatively slowly as the temperature increased. Therefore, the ignition temperature of the rice husk could be estimated around $300^{\circ}C$. Crystallization of $SiO_2$ in the rice husk ash was found from the combustion temperature of $750^{\circ}C$ and became distinctly when the combustion temperature exceeded $900^{\circ}C$. The ash became darker with $SiO_2$ crystallization.

• Journal of the Korean institute of surface engineering
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• v.5 no.2
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• pp.1-4
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• 1972

We have studied about the optimum chemical etching and sensitizing conditions of the plating on plastics. As specimen 'Mitzubishi Nobren MM2A' was used. The results were as follow. 1) The optimum chemical etching conditions. Etched the specimens for $10{\sim}40$ minutes at $70{\sim}80^{\circ}C$ with the etching solution of table 1, and for $10{\sim}15$ minutes at $65{\sim}70^{\circ}C$ with the etching solution of table 2 Table 1. Etching solution (I) Composition : $H_2SO_4(95%)-Component : 250 ml, Composition : $H_3PO_4(85%)$ - Component : 75ml, Composition : $K_2Cr_2O_7$ - Component : 12.5g, 2) The optimum sensitizing conditions. Sensitized the specimens for $60{\sim}90$ seconds at $25^{\circ}C$ with the sensitizing solution of table 3 Table 2. Etching solution (II) Composition : $H_2SO_4(95%)$ - Component : 22.5ml, Composition : $H_3PO_4(85%)$ - Component : 15ml, Composition : $CrO_3$ - Component : 105g, Composition : Water - Component : 150 ml, Table 3. Sensitizing solution Composition : $SnCl_2$ - Component : 9g, Composition : HCl(35%) - Component : 36ml, Composition : Water - Component : 300 ml

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.49-53
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• 1996

This experiment was carried out to study the effect of oxygen on chemical composition and physical properties of tobacco leaves during flue-curing. The results obtained were as follows: Starch content decreased and sucrose content increased with increasing oxygen supply during curing. Glucose and fructose of the cured leaves showed high content at the 5-10% oxygen supply. Amino-N and nitrate-N increased with increasing oxygen supply. Total nitrogen and NH4-N showed the lowest value at the 5-10% and 10-15% oxygen supply in the cutters and leaf, respectively. Chlorophyll and chlorogenic acid increased, and total volatile base decreased with increasing oxygen supply. The activity of α-amylase increased at the latter period of flue-curing, and the maximum activity point were delayed 12 hours with increasing oxygen supply. Shatter index of cured leaves decreased with increasing oxygen supply. It was desirable to supply oxygen during flue-curing for the improvement of chemical and physical properties such as starch, total sugar, chlorogenic acid, and shatter index of cured leaves.