• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.1
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• pp.36-42
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• 1997

The fiber wall filling(FWF) technology, which is based on Precipitatin of fillers in the micropores of the cell wall structure of never-dried chemical pulp fiber, has been developed to improve filling and loading process in papermaking. In presenting FWF technique here, micropores of pulp fiber are first impregnated with an ionic solution of water soluble salt and consecutively impregnated with the second salt solution. This procedure generates an insoluble precipitate within the micropores of cell wall by chemical interaction of these two ionic salt solutions This is the first attempts to use FWF technology for the quality of waste paper grade which is recycled in papermaking, even though this FWF technology has been impressively improved for never-dried chemical pulp in filling and loading process of papermaking. The precipitated amount of CaCO$_3$ and SrCO$_3$ reached 5-6% and 4-5% of the waste paper weight respectively, which was measured by ash content of the burned waste paper fiber. On the other way the precipitated amounts of those materials impregnated into never-dried chemical pulp fiber have reached 17-18% and 16-18% respectively. The micropore loading technique gives optical and physical properties to the handsheets formed with celt-wall-filled fibers which are better than those handsheet properties resulting from conventional loading. The papers made from the cell-wall-filled pulps are stronger than those with the customary location of filler between the fibers.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.226-233
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• 2013

In this study, In Laver's automatic drying device, laver thickness measurement and control devices that are associated with. Disconnect the water and steam, after put a certain amount of the mixture(water and laver) in the mold. In process, Laver of the size and thickness (weight) to determine, constant light source to detect and image LED Lamp occur Vision Sensor (Camera) prepare, then the values of these state of the image is transmitted in real time embedded computers. Built-in measurement and control with the purpose of the application of each of the channels separately provided measurements are displayed on a monitor, And servo signals sent to each of the channels and it become so set function should be. In this paper, the laver drying device, prior to the laver thickness measurement and control devices that rely on the experience of existing workers directly laver manually adjust the thickness of the lever, but the lever by each channel relative to the actuator by installing was to improve the quality. In addition, The effect of productivity gains and labor savings are.

• Korean Journal of Weed Science
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• v.15 no.2
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• pp.121-130
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• 1995

Greenhouse and laboratory studies were conducted to investigate allelopathic potential of some weed species on alfalfa(Medicago sativa L.) germination and seedling growth. In the comparison between top(leaves+stems) and root extracts, top extract exhibited greater allelopathic effects on alfalfa germination than that of root. The various weed species extract differently responded to alfalfa test species, WL-320, in terms of allelopathic effect. Top and root aqueous extracts of lambsquarter(Chenopodium album L.), giant foxtail(Setaria faberii Herrm.), redroot pigweed (Amaranthus retroflexus L.), velvetleaf(Abutilon theophrasti Medic.), crabgrass(Digitaria sanguinalis L.), canada thistle(Cirsium arvense L.) and prostrate knotweed(Polygonium aviculare L.) significantly inhibited germination, seedling length, weight, vigor, and rate of germination of alfalfa. The regression slopes of various top extracts showed that velvetleaf(b=3.69) extracts were the most inhibitory, while large crabgrass(b=2.39) extracts had the least allelopathic effect on alfalfa germination. Germination, seedling length and weight of alfalfa were inversely proportional to the concentration of dried velvetleaf extracts. Also, more of the toxic effects were observed from the dried extracts compared to the fresh extracts. Residue of velvetleaf inhibited significantly alfalfa emergence and survival percentage compared to the control. The emergence and survival percentage of alfalfa were 44%, 57% at 1.0% residue treatment, respectively. When weed residues were mixed with silica sand with incubation time, velvetleaf residue most inhibited alfalfa growth. The degree of inhibition increased as incubation time increased. An incubation for 72h caused the greatest inhibition of alfalfa growth. These results demonstrate the different allelopathic activity of weed species extracts on alfalfa and suggest that weed may affect alfalfa growth and development through the inhibitory effects of allelochemicals present in weed tissue.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.3
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• pp.403-411
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• 2001

The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. The brands studied were Unifil(GC, Japan), Palfique(Tokuyama Japan). Definite$Degussa-H\ddot{u}ls$ AG, Germany). Revolution(Kerr, U.S.A.). Preweighed discs of each brand were exposed 0.1N NaOH solution at $60^{\circ}C$. After 14 days they were removed, neutralized with HCl, washed with water and dried. Resistance to degradation was evaluated on the basis of following parameters: (a) mass loss(%) - determined from pre-and post-exposed specimen weights; (b) Si loss(ppm) - obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth$({\mu}m)$ - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were follows: 1. The mass loss of Unifil was 3.21%, it was the highest of materials. But, there was no significant difference among the materials. 2. The degree of degradation layer depth was $107.69\sim47.40{\mu}m$, the sequence of the degree pf degradation layer depth was in descending order by Unifil, Palfique, Revolution, Definite. There was significant difference among the materials except Palfique and Definite. 3. The Si loss of Paltique was 8940.0ppm, it was the highest. There was significant difference among the materials, except Revolution and Definite(p<0.05). 4. The correlation coefficient between mass loss and degradation depth was relatively high(r = 0.06, p<0.05). 5. There was no significant coefficient correlation between Si loss and mass loss, and/or the degree of degradation layer depth and Si loss. 6. When observed with SEM, destruction of bonding is observed between resin matrix and filler. Above results suggested that the hydrolytic degradation is considered as evaluation factor of composite resins.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.144-152
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• 2004

The aim of this study was to evaluate the resistance to degradation of three commercial compomers in an alkaline solution. Dyract(Dentsply), Elan(Kerr) and F-2000(3M) polyacid modified resin composites(compomers) were used in this study. The resistance to degradation was evaluated on the basis of mass loss(%), degradation $depth({\mu}m)$ and Si, Al, Ba loss(ppm). The results were as follows : 1. The mass loss of each brand was $1.42%{\sim}2.14%$ and there was no statistically significant difference of mass loss among Dyract, F2000 and Elan. 2. The degradation layer depth of each brand was $182.92{\sim}227.7{\mu}m$ and there was no statistically significant difference of degradation layer depth among Dyract, F2000 and Elan. 3. There was statistically significant differences in Si-loss and Al-loss among three compomers (p<0.05). Si loss was the highest value in Dyract and Al loss was the highest value in F2000. 4. There was statistically significant correlation between mass loss and degradation layer depth (r=0.60, p<0.05). 5. In SEM finding, there was some destruction of compomer matrix-filler interface in post-exposure specimen to NaOH solution. As the matrix decreased, the filler particles distinguished and the periphery of the filler particles appeared whitish color due to degradation.

• Culinary science and hospitality research
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• v.18 no.2
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• pp.182-196
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• 2012

This study investigates the optimal application of perilla leaves to fresh noodles in terms of a variety of beneficial effects and functions such as the anti-microbial function of the leaves. First, we measured the water contents of the fresh noodles and found that the ones added with 7% lyophilized perilla leaf extract showed the maximum water contents whereas the control noodles without perilla leaf extract the minimum. Increasing amount of raw perilla leaf extract or lysophilzed perilla leaves in the fresh noodles elevated the L value and significantly reduced the A value. The mass and volume of the fresh noodles were gradually decreased with raw perilla leaves added. Addition of raw perilla leaf extract and lyophilized perilla leaves decreased the turbidity of the fresh noodles. Hardness of the fresh noodles was increased by the addition of lyophilized Perilla leaves. Next, we tested the effect of the addition of sesame leaves on microbial growth. No microbes were found in the fresh noodles in the absence or presence of sesame leaves at day 0. When the noodles were stored for 3 days, the greatest number of bacteria was detected in the noodles without perilla leaves while addition of perilla leaves lowered the amount of bacteria in the noodles. We then performed the sensory test. For the raw perilla leaf extract addition, the noodles with 9% of extract exhibited the highest in appearance, flavor, color (6.47), texture (6.60), and overall acceptability (7.67). Texture was the highest in the ones with 3% (6.87) and 5% (6.20) of extracts added. Overall acceptability (7.07) was the best when 3% perilla leaves were added. Overall, 9% addition of raw perilla leaf extract or 3% addition of lysophilized perilla leaves showed optimal tastes.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.293-301
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• 2019

The experiment was conducted to determine the performance of DME combustion gas when used as a fuel for DME burner for raising temperature and $CO_2$ concentration in greenhouse and also to examine its effects on chlorophyll content, and fresh and dry weight of lettuce and Chinese cabbage. DME-1 and DME-2 treatments consisted of average DME flow quantity in duct were $17.4m^3min^{-1}$ and $10.2m^3min^{-1}$ respectively to greenhouse-1 and greenhouse-2 and no DME gas was supplied to greenhouse-3 which was left as control (DME-3). DME supply times were $0.5hr\;day^{-1}$, $1hr\;day^{-1}$, $1:30hrs\;day^{-1}$ and $2hrs\;day^{-1}$ on week 1, 2, 3, and 4 respectively. Chlorophyll content and fresh and dry weight of lettuce and Chinese cabbage were measured for each treatment and analyzed through analysis of variance with a significance level of P<0.05. The result of the study showed that $CO_2$ concentration increased up to 265% and 174% and the level of temperature elevated $4.8^{\circ}C$ and $3.1^{\circ}C$ in greenhouse-1 and 2, respectively as compared to greenhouse-3 due to application of DME combustion gas. Although, the same crop management practices were provided in greenhouse-1, 2 and 3 at a same rate, the highest change (p<0.05) of chlorophyll content, fresh weight and dry weight were found from the DME-1 treatment, followed by DME-2. As a result, DME combustion gas that raised the level of temperature and $CO_2$ concentration in the greenhouse-1 and greenhouse-2, might have an effect on growth of lettuce and Chinese cabbage. At end of experiment, the highest fresh and dry weight of lettuce and Chinese cabbage were measured in greenhouse-1 and followed by greenhouse-2. Similarly chlorophyll content of greenhouse-1 and greenhouse-2 were more compared to greenhouse-3. In general, DME was not producing any harmful gas during its combustion period, therefore it can be used as an alternative to conventional fuel such as diesel and liquefied petroleum gas (LPG) for both heating and $CO_2$ supply in winter season. Moreover, endorsed quantify of DME combustion gas for a specified crop can be applied to greenhouse to improve the plant growth and enhance yield.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.673-682
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• 2001

The use of resin composites has continued to increase over the last several years. In spite of their growing popularity, composites continue to exhibit a number of undesirable characteristics. One of the major deficiencies of composite restorative resins is their inadequate resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. This solution with a high concentration of hydroxyl ions is a convenient medium for accelerated degradation of silane coupling and filler particles. The brands studies were Definite($Degussa-H\ddot{u}ls$ AG, Germany), Prodigy(Kerr, USA), Pyramid(Bisco, USA) and Synergy(Coltene, Swiss). Preweighed discs of each brand were exposed to 0.1N NaOH solution at $60^{\circ}C$. After 14 days they were removed, neutralized with HCl, washed with water and dried. Resistance to degradation was evaluated on the basis of following parameters : (a) mass loss(%)-determined from pre-and post-exposed specimen weights : (b) Si loss(ppm)-obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation $depth({\mu}m)$-measured microscopically (SEM) from polished circular sections of exposed specimens. The results were follows: 1. Mass loss of Synergy was $1.24{\pm}0.002%$, it was the highest, there was no significant difference among the materials. 2. The degree of degradation layer depth of Synergy was $107.83{\pm}2.52{\mu}m$, it was the highest, there was no significant difference among any other materials than Synergy. 3. There was no difference among the four materials in Si loss. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.06, p<0.05). 5. There was no coefficient correlation between Si loss and mass loss, the degree of degradation layer depth and Si loss. 6. When observed with SEM, destruction of bonding is observed between resin matrix and filler.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.227-235
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• 2020

In this study, we discussed the limitations of gross alpha measurements for the characterization of radioactive wastes produced in nuclear facilities through experimental tests and Monte Carlo N-particle transport simulations. The determination of gross alpha is essential for the disposal of radioactive waste produced in nuclear facilities in Korea. The measurements of gross alpha are easy to perform and yield rapid analytical results, but it cannot be used for quantitative analysis. The error of counting efficiency for gross alpha with various masses of the deposit on planchets using KCl and ²⁴¹Am was determined. The relative deviation of the counting efficiency in samples having the same mass was 20%. Uranium was extracted from the soil through acid leaching and extraction chromatography, and the concentration of U determined by inductively coupled plasma-mass spectrometry (ICP-MS) was compared with the results for gross alpha. The gross alpha was underestimated by 50% compared to the U concentration by ICP-MS. The counting efficiency depended on the energy from the alpha emitters, which differed by up to three times in determination of the counting efficiency depending on the kinds of alpha radionuclides of interest. Therefore, the gross alpha is not compatible with the sum of radioactivity for each alpha emitter and is suitable as a screening method.

• Journal of Mushroom
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• v.15 no.2
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• pp.69-72
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• 2017

Diversification to develop oak pruned neck utilization technology reduction of operation cost of cheonma(Gastrodia elata) farmers is the purpose of this research, but the results of the experiment are as follows. The soil chemistry of the plantation was very weak in 2015 when the pH was 5.7, weakly acidic and EC was 0.41 (ds/m), but the faux spring area was very sunny, but at the end of May, early June, late July And so on were at a maximum temperature of $25^{\circ}C$ or more, and underground temperature fell below freezing in late January 2016. In the content of the survey of the harvested volume, treatment with a diameter of 6 to 10 cm appeared in 1,366 g total weight and in treated plots with a diameter of 20 cm or more, appeared in 1,542 g, confirming that the number and weight of the interspaces from the small neck is higher than the practice.