• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.251-254
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• 1977

Pectin, hesperidin and naringin were extracted from hot air-dried peel ($60^{\circ}C$, 1 hr and air velocity 160 fpm) of citrus produced in Korea in order to see the amount of each component contained in the peel. Pectin was extracted by three different methods and the quality and contents of the pectins were determined respectively. 1. The pectin yield by the total pectic substance method was the highest (26.0% for unshiu (U) and 28.5% for natsudaidai (N) expectedly and the soluble pectic substance method the least (13.5%(U) and 15.6% (N)) The yield by method III (extraction by water at pH 1.5 followed by isopropanol precipitation) was intermediate (18.1% (U) and 20.8%(N)). Anhydrouronic acid (AUA) content was the highest (92.0% (U) and 90.3%(N)) in those by method III. The AUA contents of the other pectins were 80.0% for soluble pectin (for both U and N), 71.6% for the commercial pectin (Sunkist Groups Inc., U.S.A.), 58.0%(N) and 63.4%(U) for total pectic substance. 2. The methoxyl content of total pectic substance was the lowest (4.81%(U) and 4.88%(N)). However, there was no significant difference in methoxyl content among the rest which were found to have low levels(5.27-7.20%). 3. The pectin by method III gave the highest jelly strength. The commercial pectin, soluble pectice substance and total pectic substance were next in order. 4. The hesperidin content of unshiu was 5.07% (dry basis) and the naringin content of natsudaidai 3.03% (dry basis).

• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.63-68
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• 1998

Multiple shoots obtained in MS medium suppler with 5.0 mg/L BA though shoot-tip culture. The frequency of vitrified shoot was lower on Bacto-agar medium than on Gelrite as gelling agent. Addition of activated charcoal at concentrations of 0.1~0.3% reduced vitrification and markedly increased shoot growth, and formation and growth of roots, but significantly reduced the number of shoots formed. The ratio of fresh weight to dry weight was decreased by increasing light intensity and agar concentration. Eight-tenths times of macroelement of MS medium was observed to be effective for shoot formation. Addition of IAA effectively promoted shoot formation in both shoot tip and node-bud explants. Supplement of 5.0 mg/L BA, 0.3 mg/L IAA to MS medium was most effective in shoot proliferation on shoot tip and node-bud explants.Multiple shoots obtained in MS medium suppler with 5.0 mg/L BA though shoot-tip culture. The frequency of vitrified shoot was lower on Bacto-agar medium than on Gelrite as gelling agent. Addition of activated charcoal at concentrations of 0.1~0.3% reduced vitrification and markedly increased shoot growth, and formation and growth of roots, but significantly reduced the number of shoots formed. The ratio of fresh weight to dry weight was decreased by increasing light intensity and agar concentration. Eight-tenths times of macroelement of MS medium was observed to be effective for shoot formation. Addition of IAA effectively promoted shoot formation in both shoot tip and node-bud explants. Supplement of 5.0 mg/L BA, 0.3 mg/L IAA to MS medium was most effective in shoot proliferation on shoot tip and node-bud explants.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.579-585
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• 2012

This study was carried out to investigate the effect of potassium silicate on the growth and leaf epidermal characteristics of horticultural crops viz., begonia (Begonia semperflorens Link et Otto) 'Super Olympia Red' and 'Super Olympia Rose' and pansy (Viola ${\times}$ wittrockiana Hort.) 'Matrix White Blotch' and 'Matrix Yellow Blotch' in vitro. Seeds after germination were grown on a quarter strength MS medium supplemented with potassium silicate ($K_2SiO_3$) at 0, 100, 200, or $300mg{\cdot}L^{-1}$ and were maintained under a photoperiod of 16 hours at $25^{\circ}C$. Growth parameters such as plant height, root length, chlorophyll content, fresh, and dry weights have been recorded after a growth period of 58 days for begonia and 94 days for pansy. In begonia, fresh weight was significantly greatest in the $200mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment in both 'Super Olympia Red' and 'Super Olympia Rose'. In both pansy cultivars, fresh weight was the greatest in the $200mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment than other treatments. Chlorophyll content was significantly greater in the $100mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment for both the cultivars of begonia. Leaf area significantly increased with the higher concentrations of $K_2SiO_3$ treatment in both cultivars of pansy. Stomatal structures on the leaf epidermis were observed with scanning electron microscopy (SEM). In begonia 'Super Olympia Rose', the structure of stomata were more compact in size in the $300mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment than in the control. Similarly, in pansy 'Matrix White Blotch' the surface of stomata appeared to be smoother in the $300mg{\cdot}L^{-1}$ $K_2SiO_3$ treatment than those wrinkled appearance in the control. The surface of the leaf epidermis appeared to be compact due to Si deposition, and thus results indicated that Si positively affected the growth and biomass production of these species. Our data show that the effect of Si on growth parameters is strongly dependent on cultivar of the plant species tested.

• International Journal of Highway Engineering
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• v.3 no.4 s.10
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• pp.117-126
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• 2001

In this research, evaluation of adhesion in tension property of SBR-modified concrete to ordinary portland cement concrete was conducted with uniaxial direct tensile bond test which was proposed by Kuhlmann. A test set-up was fabricated in order to minimize the eccentric force by introducing a joint which might fully rotate. The main experimental variables were cement-latex ratios, surface preparations and moisture levels. The results obtained were as follows: The LMC specimen at 15% latex-cement ratio increased the adhesion in tension by range of 37% compared to that of conventional cement concrete. This might be due to latex film formed between cement paste and aggregate. The effects of surface preparation on bond of latex modified concrete to conventional concrete were significant at the conditions by sand paper and wire brush. A better bond could be achieved by rough surface rather than smooth. The saturated and surface dry (SSD) condition were considered to be the most appropriate moisture level followed by wet, finally by dry. Thus, a proper surface preparation and moisture level are quite necessity in order to obtain better bonding at LMC overlay.

• Geomechanics and Engineering
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• v.14 no.3
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• pp.247-255
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• 2018

Soil stabilization can make the soils becoming more stable by using an admixture to the soil. Lime stabilization enhances the engineering properties of soil, which includes reducing soil plasticity, increasing optimum moisture content, decreasing maximum dry density and improving soil compaction. Silica fume is utilized as a pozzolanic material in the application of soil stabilization. Silica fume was once considered non-environmental friendly. In this paper, the materials required are kaolin grade S300, lime and silica fume. The focus of the study is on the determination of the physical properties of the soils tested and the consolidation of kaolin mixed with 6% silica fume and different percentages (3%, 5%, 7% and 9%) of lime. Consolidation test is carried out on the kaolin and the mixtures of soil-lime-silica fume to investigate the effect of lime stabilization with silica fume additives on the consolidation of the mixtures. Based on the results obtained, all soil samples are indicated as soils with medium plasticity. For mixtures with 0% to 9% of lime with 6% SF, the decrease in the maximum dry density is about 15.9% and the increase in the optimum moisture content is about 23.5%. Decreases in the coefficient of permeability of the mixtures occur if compared to the coefficient of permeability of kaolin soft clay itself reduce the compression index (Cc) more than L-SF soil mix due to pozzolanic reaction between lime and silica fume and the optimum percent of lime-silica fume was found to be (5%+6%) mix. The average coefficient of volume compressibility decreases with increasing the stabilizer content due to pozzolanic reaction happening within the soil which results in changes in the soil matrix. Lime content +6% silica fume mix can reduce the coefficient of consolidation from at 3%L+6%SF, thereafter there is an increase from 9%L+6%SF mix. The optimal percentage of lime silica fume combination is attained at 5.0% lime and 6.0% silica fume in order to improve the shear strength of kaolin soft clay. Microstructural development took place in the stabilized soil due to increase in lime content of tertiary clay stabilized with 7% lime and 4% silica fume together.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.56-64
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• 2009

The purpose of this study was to investigate and develop an eco-friendly wood adhesive based on vegetable oil (especially soybean oil), the renewable and sustainable natural resources, using ozonification technology for the chemical structure modification. The soybean oil (SBO) was reacted with $O_3$ at the rate of 7.13 g/h for different times, 15 minutes, 30 minutes, 60 minutes, and 120 minutes. The investigation of the modified chemical structure of the ozonized SBOs were conducted using FT-IR, $^1H$-NMR, MALDI-TOF MS, and GC/MS. As ozonification time increased, the peak of the unsaturated double bonds was disappeared and aldehyde or carboxyl peak appeared because ozonification broke the oil into small molecules. The plywoods were made at $110^{\circ}C$ with 30 seconds/mm hot-press time using the different ozonized SBO/pMDI adhesives and were tested for the dry, wet, cyclic boil test according to the Korea Industrial Standard F3101 Ordinary plywood. The bond strengths gradually increased with increasing ozonification time. The weight ratio 1:1 (ozonized SBO/pMDI), all strengths in 15, 30 and 60 minuets, exceeded constantly the dry, wet, cyclic boiling standard requirement. The range of ozonification time and weight ratio can fulfil1 the requirment of the wet test standard were 30~60 minutes and more than 0.5 pMDI. From the comprehensive view on the results of above experiments, it could be confirmed through experiments that ozonized SBO/pMDI has characteristics of effective reactivity and wet stability showed as an excellent candidate of wood adhesive applications.

• Journal of the Korean Vacuum Society
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• v.17 no.3
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• pp.175-182
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• 2008

This study is concerned with the evaluation of the corrosion resistance of coated semiconductor equipment parts with various processes. To select the appropriate basis for evaluation, replacement parts were observed during the semiconductor manufacturing process. This study also ran a dry corrosion test using $Al_2O_3$, which is mostly used as a coating material. This test quantitatively measured the efficiency of coated parts. Surface morphology, leakage current and breakdown voltage were also evaluated. This study showed that a dry corrosion process led to the drop of electrical properties, for example, the leakage current increase and the dielectric strength decrease. The surface morphology test displayed that surface damage is largely dependent on the exposure time to corrosive environments. By using the values that changed during the corrosion process, it may be possible to contrive a method to evaluate the efficiency of coated parts with various processes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.550-556
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• 1992

Performance of a rice breeding line, Milyang 95 was evaluated at four cultural methods, direct seeding on dry soil covered by making ridges (DS ridged), direct seeding on dry soil covered by rotortilling (DS rotary), direct seeding on flooded soil (FS), and machine transplanting (MT). Days from seeding to emergence in both DS ridged and DS rotary was 15 days. The number of seedlings at DS ridged and DS rotary was lower than that at FS. Heading was earliest at MT, latest at DS rotary and DS ridged, and that at FS was between them. Days from seeding to heading was 115 days at MT, 94-95 days at DS ridged and DS rotary, and 87 days at FS. Lodging index was similar among the cultural methods and lodging was not occurred in the field although fresh weight of tillers and breaking strength at MT were higher than those of direct seedings. Yield and most of yield components were similar among the cultural methods although the number of spikelets per panicle at MT was higher and 1,000 grain weight at FS was lower compared to other cultural methods. Grain appearance (rusty, chalky abortive rice), protein and amylose contents and alkali digestibility were observed.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.126-131
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• 1997

This experiment was conducted to obtain the basic information on ability of germination at low temperature with 26 cultivars of Korea including USA cultivars and to identify the optimal sowing depth in dry-direct seeded rice. Varietal difference in germination rate and days to emergence at low temperature($13^{\circ}C$) was observed. Average germination was 81.2% and range of germination rate showed 64.3 to 94.8%. In days to germination there was varietal difference. Average days to germination was 17.4 days and those range showed 14 to 24days. Negative high correlation was observed between the ability of germination and days to germination. Considering germination and days to germination. Jakwangdo, Nagdongbyeo, Cheongmeongbyeo, Calom, Anjungbyeo, Gyehwabyeo, Daegwanbyeo, Dongjinbyeo and Seohaebyeo were selected as a adaptable cultivar. High correlation was observed among the lodging index and sowing depth, stem diameter, height of central gravity, breaking strength. Seedling emergence was increased and days to emergence was shortened at the seeding depth of 1 and 3cm. Lodging index was decreased as seeding depth was deep and so the reasonable seeding depth would be around 3cm in direct seeded rice.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.385-392
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• 2018

The slope stabilization analysis was performed by conducting survey and selecting the representative section in order to improve slope composition and management technology of masonry embankments in the quarry area, The mean slope of the masonry retain wall (A, B, C, D, E, F) was $38.5^{\circ}$, although the steep slope of the lowest slope (A) as $59^{\circ}$. The horizontal distance of the masonry embankments is 66.2 m and the slope height is 48.3 m. However, the inclination of the masonry embankments is relatively steep and visually unstable. The slope stability analysis for the slope stability analysis was taken into account during the drying and saturation. The slope stability analysis during saturation was performed by modeling the fully saturated slope. The strength constants of the ground were divided into two groups. The safety factor for dry period was 1.850 and the safety factor for rainy season was 1.333. The safety rate of dry period and rainy season was above 1.5 and 1.2. However, the weathered granite on the upper part of the masonry embankments at the time of heavy rainfall is considered to have a high risk of slope erosion and collapse. Therefore, it is considered necessary to take measures for stabilization through appropriate maintenance such as drainage installation.