• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.303-314
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• 2002

This study was performed to evaluate the usability of Er:YAG laser for periodontal therapy. Forty dental root slabs ($5{\times}5{\times}2mm^3$) were prepared from human periodontally diseased extracted teeth and grouped into 4 groups: 1) control (root planing only), 2) root planing and irradiated with laser at 30mJ, 3) root planing and irradiated with laser at 60mJ, and 4) root planing and irradiated with laser at 100mJ. The root slabs were embedded in resin block before laser treatment. Er:YAG laser was irradiated under water irrigation with the tip held perpendicular to the root surface in contact mode. After Er:YAG laser irradiation or planing on the root surface, morphological changes have been observed under SEM, and the micro-hardness and Ca/P ratio were compared. 1. In the Control group, the root surface showed the directional change caused by root planing instrumentation, and the presence of smear layer, and no exposure of dentinal tubule was observed. Laser irradiated group showed surface changes with rough dentin surface of niche and depression and dentinal tubule exposure by the elimination of smear layer. 2. The micro-hardness of root surface in the laser irradiated group was higher than the control group. The higher energy output was applied, the higher micro-hardness on root surface was resulted. 3. The higher energy output was applied, the higher Ca/P ratio was observed. The higher Ca/P ratio in 60mJ group and 100mJ group was statistically significantly compared to the control group and the 30mJ group. These results suggest that Er:YAG laser irradiation on the periodontally diseased root surface could remove smear layer and increase the micro-hardness on root surface and Ca/P ratio which contribute to enhance the acid resistance of periodontally treated root surface.

• Journal of Korean Society of Forest Science
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• v.56 no.1
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• pp.66-76
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• 1982

Soil harness represents such physical properties as porosity, amount of water, bulk density and soil texture. It is very important to know the mechanical properties of soil as well as the chemical in order to research the fundamental phenomena in the growth and the distribution of tree roots. The writer intended to grip soil hardness by soil layer and also to grasp the root distribution and the correlation between soil hardness and the root distribution of Pinus riguda Mill. planted on the denuded hillside with sooding works by soil layer on soil profile. The site investigated is situated at Peongchang-ri 13, Kocksung county, Chon-nam Province. The area is consisted of 3.63 ha having on elevation of 167.5-207.5 m. Soil texture is sandy loam and parant rock in granite. Average slope of the area is $17^{\circ}-30^{\circ}$. Soil moisture condition is dry. Main exposure of the area is NW or SW. The total number of plots investigated was 24 plots. It divided into two groups by direction each 12 plots in NW and SW and divided into three groups by the position of mountain plots in foot of mountain, in hillside, and in summit of mountain, respectively. Each sampling tree was selected as specimen by purposive sampling and soil profile was made at the downward distance of 50cm form the sampling tree at each plot. Soil hardness, soil layer surveying, root distribution of the tree and vegetation were measured and investigated at the each plot. The soil hardness measured by the Yamanaka Soil Hardness Tester in mm unit. the results are as follows: 1) Soil hardness increases gradually in conformity with the increment of soil depth. The average soil indicator hardness by soil layer are as follows: 14.6mm in I - soil layer (0-10cm in depth from soil surface), 16.2mm in II - soil layer (10-20cm), 17.2 in III - soil layer (20-30cm), 18.3mm in IV - soil layer(30-40cm), 19.8mm in V - soil layer (4.50mm). 2) The tree roots (less than 20mm in diameter) distribute more in the surface layer than in the subsoil layer and decrease gradually according to the increment of soil depth. The ratio of the root distribution can be illustrated by comparing with each of five soil layers from surface to subsoil layer as follows: I - soil layer; 31%, II - soil layer; 26%, III - soil layer; 18%, IV - soil layer; 12%, V - soil layer; 13%, 3) Soil hardness and tree root distribution (less than 20mm in diameter) of Pinus rigida Mill. correlate negatively each other; the more soil hardness increases, the most root distribution decreases. The correlation coefficients between soil hardness and distribution of tree roots by soil layer are as follows: I - soil layer; -0.3675 (at the 10% significance level), II - soil layer; -0.5299 (at the 1% significance level), III - soil layer; -0.5573 (at the 2% significance level), IV - soil layer; -0.6922 (at the 5% significance level), V - soil layer; -0.7325 (at the 2% significance level). 4) the most suitable range of soil hardness for the growth of Pinus rigida Mill is the range of 12-14.9mm in soil indicator hardness. In this range of soil indicator hardness, the root distribution of this tree amounts to 41.8% in spite of 33% in soil harness and under the 20.9mm of soil indicator hardness, the distribution amounts to 93.2% in spite of 82% in soil hardness. Judging from above facts, the roots of Pinus rigida can easily grow within the soil condition of 20.9mm in soil indicator hardness. 5) The soil layers are classified by their depths from the surface soil.

• Journal of Ginseng Research
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• v.19 no.3
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• pp.287-290
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• 1995

This study was conducted to elucidate the effect of physical properties of soil in nursery bed with different densities on growth of ginseng seedling. Stem length, leaf length and leaf width of ginseng seedling showed the decreasing tendency with increasing the hardness of the nursery soil. Fresh root weight per seedling and number of available seedlings were increased significantly with decrease of the soil hardness. For solid, liquid phases, bulk density and hardness of soil, negative correlations were shown in stem length, leaf length, leaf width, root weight per seeding, and number t of available seedlings. On the other hand, gas phase, air permeability and porosity of soil had positive correlations with stem length, leaf length, leaf width, root weight per seedling and number of available seedlings. Key words Yang-Jik nursery, ginseng seedling, soil physical properties.

• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.315-324
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• 2002

The purpose of this in vitro study was to evaluate the efficiency of Er:YAG laser on calculus removal and the morphologic changes and hardness of the irradiated surface at different power settings. This experiment used human teeth which were extracted due to periodontal disease and had a band of calculus. Forty root slabs ($5{\times}5mm$) were made and divided into control group and irradiated groups. Experimental groups were as follows; Control group (root planing), Group1 (irradiated with laser at 30mJ), Group2 (irradiated with laser at 60mJ), Group3 (irradiated with laser at 100mJ). Twelve root slab embedded in resin block were used in each group. Er:YAG laser was applied under water irrigation with the tip held perpendicular to the root surface in contact mode. The treatment time was measured until the calculus was removed completely under naked eyes. The efficiency of calculus removal was evaluated by the time for removal. Morphological changes of laser irradiated site were observed under SEM and the surface hardness was measured using a VH tester. The results were as follows; 1. The efficiency of laser scaling was increased with increasing the energy level of irradiation(p<0.05). 2. The morphological changes such as carbonization, crater and scale-like defects in the irradiated root surface were frequently observed with increasing the energy level. 3. The surface hardness tended to increase at 60mJ and 100mJ irradiated groups than that of control group. From the results evaluting on the efficiency, morphological change and surface hardness, lower energy level was suggested for the clinical application of the Er:YAG laser in scaling.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.47-55
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• 2011

Cicada is a very familiar insect to people but habitat characteristics of them are not well known. To investigate habitat characteristics of cicada nymph, plant species, plant cover, soil hardness, accumulated organic mass, organic content in soil, and root density were investigated at 11 sites in an apartment complex garden in Seoul. Selected sites had different densities of cicada nymph case above the ground. Density of cicada nymph case was positively correlated with accumulated organic mass, organic content in soil, and root density and negatively correlated with soil hardness. Even though shrub coverage was not linearly correlated with the density of cicada nymph case, 80% cover of shrub was necessary for the high density of them. Data in this study suggested that organic matter in addition to root density be the primary limitation factor of cicada nymph and high amount of litter-fall decrease soil hardness through the increase of soil organic matter. This study suggests that the density of cicada nymph can be managed through organic content in soil.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.217-222
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• 1995

Experiments were conducted to study the effect of IBA, mineral stone and stem hardness on rooting characteristics in mature Aloe vera plant. The rooting ability in matured Aloe vera was of highly significance when the amount of IBA treatment was increased to 5.000mg/l. The treatment of IBA 5.000mg/l, together with mineral stone(v/w 1.5 times), gave more root number, the length and the dry weight of root were, also, higher in semihard wood cutting than soft wood cutting in matured Aloe vera.

• Food Science and Preservation
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• v.16 no.1
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• pp.53-59
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• 2009

The purpose of this research is to develop bellflower (Platycodon grandiflorum) root and lotus (Nelumbo nucifera) root Jeonggwa as a health food. The quality characteristics of Jeonggwa to which 0-8% (w/w) of Omija (Schizandra chinensis Baillon) water extract was added were investigated. The moisture contents of bellflower root Jeonggwa were 14.9-18.0%, where as that of lotus root Jeonggwa was 6.9-8.4%. The acidity of bellflower root Jeonggwa was 0.477-0.585% and that of lotus root Jeonggwa was 0.513-0.572%; values increasing levels of Omija extract. The lightness (L) and yellowness (b) values of bellflower root Jeonggwa decreased with increasing amounts of Omija extract, and the lightness (L), redness (a) and yellowness (b) values of lotus root Jeonggwa decreased with increasing Omija extract concentration (p<0.05). In mechanical tests with bellflower root Jeonggwa, the highest values of hardness and strength were seen at 2% (w/w) extract, of cohesiveness were seen with 4-8%, of springiness with 2-6%, of gumminess with 6-8%, and of brittleness with 4-6% (all p<0.01). In mechanical tests with lotus root Jeonggwa, the highest values of hardness and springiness were at 0 and 6% extract, respectively, whereas strength, gumminess and brittleness were at 6-8% Omija extract (all p<0.01). In sensory evaluation, the highest acceptability of bellflower root Jeonggwa was seen with 4% extract and that of lotus root Jeonggwa was seen with 2% extract.

• Culinary science and hospitality research
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• v.16 no.1
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• pp.180-190
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• 2010

This study investigates the quality characteristics of mung bean starch Jelly by addition of different ratios of white lotus(Nelumbo nucifera) root powder during 5 days of storage at $4^{\circ}C$. The moisture content of the samples ranged from 86.78 to 88.88%. The L value of the samples decreased as the amount of white lotus root powder increased; however, the a value and b value were significantly(p<0.05) increased. For the sensory evaluation, color and taste were decreased as the amount of white lotus root powder increased. Flavor and shine were not significantly different among the samples. And clarity and elasticity were highest in the sample with no powder and 5% of white lotus root powder. Hardness was decreased(p<0.05) as the amount of white lotus root powder increased. Overall acceptability was highest when using 0% and 5%. Texture profiles of hardness decreased as the amount of white lotus root powder increased. Hardness, gumminess, chewiness were found to drop significantly(p<0.05) after one day of storage. Cohesiveness was not significantly different among the samples according to the amounts of white lotus root powder. Adhesiveness was not significantly different in 0, 5, 10, and 15% of white lotus root powder. Syneresis was increased during the storage period. From the result, the most advisable mixture ratio of mung bean starch jelly with white lotus root powder was 19 g of mung bean starch, 1g of white lotus root, 0.1 g of salt and 160 mL of water.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.4
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• pp.516-523
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• 2010

This study was conducted to investigate the physicochemical and sensory characteristics of tofu prepared with the addition of lotus root powder (LRP). The moisture, crude ash, carbohydrate, crude protein, and crude lipid contents of the lotus root powder were 8.29%, 4.73%, 30.66%, 47.84%, and 8.48%, respectively. The yield rate of the tofu did not differ significantly according to the level of added LRP; however, there was a significant decrease in pH and a significant increase in acidity. The L and b values of the tofu decreased as the amount of LRP in the formulation increased, whereas the a value increased. Furthermore, hardness and cohesiveness increased significantly as the level of LRP increased. In sensory evaluation, LRP tofu had low scores in air cell size and a beany smell, but high scores in hardness. In terms of overall acceptability, the preferred tofu samples were the control and that containing 0.3% lotus root powder.

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.143-149
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• 2009

The objective of this study was to evaluate the quality characteristics of lotus root Dasik prepared by different additions of lotus root powder (0%, 20%, 40%, 60%, 80%). As the level of lotus root powder in the formulation increased, the moisture contents of samples increased. Also, the L-, a-, and b-values of samples significantly decreased as the amount of lotus root powder increased. According to the results for mechanical characteristics, hardness, gumminess, springiness, cohesiveness, and chewiness decreased, whereas adhesiveness increased, as the amount of lotus root powder increased. The sensory evaluation results showed that the 40% lotus root sample received the highest preference scores; therefore, the 40% lotus root Dasik prepared with 60 g of flour, 40 g of lotus root powder, and 80 g of honey was chosen as the superior product.