• The korean journal of orthodontics
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• v.33 no.5 s.100
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• pp.359-370
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• 2003

The purpose of this study was to evaluate the bond strength of orthodontic brackets bonded to metal bar with chemically cured adhesive (Ortho-one, Bisco Co, USA) in various types and directions of force application. Three types of metal bracket with different bracket base configurations; Micro-Loc base(Tomy Co, Japan), Chessboard base(Daesung Co, Korea), Non-etched Foil-Mesh base(Dentaurum, Germany); were used in this study. Peel, shear, tensile bond strengths were measured by universal testing machine and compared each other. The peel force directions applied were $0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;60^{\circ},\;75^{\circ},\;90^{\circ}$ And then, in consideration of the different surface area of the bracket bases, the bond strength Per unit area were calculated and compared. The results obtained were summarized as follows: 1. The bond strengths according to the types and the directions of the forces were greatest at the shear forces in all three bracket base configuration groups(p<0.01). 2. As the peel force direction grew higher in degree, peel bond strength decreased. The Patterns of peel bond strength change according to force direction was similar in all three bracket base configurations. The minimum bond strength was 60 degree-peel bond strengths in all three bracket base configurations. 3. In Micro-Loc base group, minimum peel bond strength$(_{60}PBS)$ was in $29\%$ level of shear bond strength and $52\%$ level of tensile bond strength. In Chessboard base group, $_{60}PBS$ was in $34\%$ level of shear bond strength and $61\%$ level of tensile bond strength. In Non-etched Foil-Mesh base group, $_{60}PBS$ was in $34\%$ level of shear bond strength and $55\%$ level of tensile bond strength. 4. The bond strengths per unit area were lowest in Non-etched Foil-Mesh base group and highest in Chessboard base group(p<0.05). However, there were no differences in shear bond strength, tensile bond strength, $75^{\circ}\;and\;90^{\circ}$ per unit area between Micro-Loc and Chessboard base groups.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.47-55
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• 2009

This study was carried out to investigate the effects of spider-derived protease [Arazyme (AZ)] supplementation on egg production, egg quality, cecal microflora and viscosity of intestinal contents in laying hens at the late production. A total of two hundred, 59-wks-old, Hy-Line Brown layers were divided into four groups, placed into 5 replicates per group (50 birds per group) and fed one of four diets containing 0.05, 0.075 or 0.1% AZ or control for 5 wks. The results showed that egg weight in group fed the diet containing 0.05% AZ was significantly higher than those of other groups (P<0.05). There were no significant differences in egg interior and eggshell qualities among the groups. The serum parameters such as total cholesterol, the levels of GOT and GPT were not influenced by AZ feeding. There were no significant differences in the cecal number of total microbes, Coliforms and lactic acid bacteria among the groups. The viscosity and ammonia concentration of intestinal contents in the groups fed AZ were significantly reduced compared to those of the control (P<0.05). In conclusion, laying hens fed AZ supplemented diet improved egg weight as compared with that of control. In addition, the AZ supplemented diet reduced the viscosity and ammonia concentration of intestinal contents, reflecting a significant feed enzyme effect.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.9-15
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• 1995

This study was carried out to investigate the effects of the optimal fertilizer application levels and planting space at different seeding parts on Chinese yam from 1992 to 1993. The results obtained was as follows： The earlist day to emergence was 42~56 days at tuber section, 37~46 days at an aerial tuber, and 50~56 days at an exposed parent material. in turn. The days to emergence were delayed by increasing fertilizer application levels. In the growth of the under-ground parts, vine length was increased in a tuber section, aerial tuber, and an exposed parent material in turn. The tuber section by 60${\times}$20cm at planting space, 56-56-64 Kg/10a at fertilizer application levels was appeared to be good growth among underground parts. As planted close, the growth of tuber section was decreased. The totoal yield was appeared to be increased about 19% in a tuber section planted as 30${\times}$20cm compared with 60${\times}$20cm. In an exposed parent ma-terial, the planting space, 30${\times}$15cm, was increased 10% compared with 45${\times}$15cm, and in an aerial tuber, the planting space, 10${\times}$10cm, was increased about 10% comparing 30${\times}$10cm. Fertilization level(N-$P_2O_2K_2O$) in 56-56-64Kg/10a was increased 39 to 47% comparing 28-28-32 Kg/10a. And the heavy dressing and the close planting space were appeared to be produced the highest yield. In considering commercial quality, the optimal combination between seeding parts and planting space is recommended to improve commercial qualities and high yield.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.215-221
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• 2008

Effects of light generated by LEDs on shoot growth and rooting of Tsuru-rindo(Tripterospermum japonicum) were evaluated. Apical shoots(one or two node with 3-4 leaves) were cultured on MS basal medium with 3% sucrose and maintained for four weeks under five different light qualities: fluorescent lamp(F), 100% red LED(R), 70% red LED+30% blue LED(R7B3), 50% red LED+50% blue(R5B5), or 100% blue LED(B). Rooting was promoted by both red light and fluorescent lamp, and the effect was further promoted under the ventilation. Red light enhanced shoot node elongation, whereas blue light appeared to suppress it. Growth of shoots and leaves were enhanced under the ventilation irrespective of the different light qualities. Under the ventilated condition, total fresh weight of plants was highest in R7B3 LED as 257.7 mg per plant. Dry matters, which are used for index of plant growth, were lowest under red light, whereas it was highest under blue light. The dry matter was inclined to getting higher by ascending the ratio of blue light and red light. Total chlorophyll content was highest in both R7B3 LED and R5B5 LED under ventilation as 29.5 and 31.2, respectively. Above results suggest that light quality optimization could be an important factor to foster in vitro growth of the species. Ventilation treatment appeared to be another important factor to induce normal shoot growth and rooting.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.72-79
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• 2018

Purpose: The purpose of this study was to compare flexural strength and elastic modulus of several splinting materials dependent on water absorption. Materials and Methods: Three different materials; LightFix, G-FIX, G-aenial Universal Flo; were used in this study. Thirty rectangular bar specimens ($25{\times}2{\times}2mm$) of each materials were prepared. Fifteen specimens of each materials were stored in 100% relative humidity atmosphere, $37^{\circ}C$ for 24 hours. The other specimens were stored in distilled water, $37^{\circ}C$ for 30 days. Flexural strength and elastic modulus were calculated using Universal testing machine. One-way ANOVA and Scheffe's post hoc test at 95% level of significance were used on all test results. Results: In LightFix, flexural strength and elastic modulus were significantly decreased after aging. In G-FIX, there was no significant change in flexural strength and elastic modulus after aging. In G-aenial Universal Flo, flexural strength was significantly decreased, but elastic modulus did not change significantly. Statistical analysis reveals that flexural strength and elastic modulus increased in the order of LightFix, G-FIX, G-aenial Flo in both 24 hours and 30 days. Conclusion: It could be deduced from this study that flexural strength and elastic modulus of some resins could be changed when it aged in oral environment. Thus this should be considered when choosing a resin to perform a resin-bonded splint.

• Journal of Environmental Policy
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• v.5 no.1
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• pp.45-70
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• 2006

China has achieved great economic growth above 9% annual since it changed to more of a market economy system by its reform and open-door policy. At the same time, China has experienced severe ecological deterioration, such as air and water pollutions caused by its rapid urbanization and industrialization. China is now confronted with environmental pollution and ecological deterioration at a critical point, at which economic development in China is limited. Moreover, environmental problems in China have become a lit fuse for social fluctuation beyond pollution problems. The root and background of environmental problems in China, firstly, are its government's lack of understanding of these problems and incorrect economic policies affected by political and ideological prejudice. Secondly, the plundering of resources, 'the principle of development first' which didn't consider environmental sustainability is another source of environmental deterioration in China. In addition, a huge population and poverty in China have increased the difficulty in solving its environmental problems, and in fact have accelerated them. The Chinese government has established many environmental laws and institutions, increased environmental investments, and is enlarging the participation of NGOs and the general public in some limited scale to solve its environmental problems. However, it has not obtained effective results because of the lack of environmental investments owing to the government's limit of the development phase, a structural limit of law enforcement and local protectionism, and the limit of political independency in NGOs and the lack of public participation in China. It seems that China remains in the stage of 'economic development first, environmental protection second', contrary to its catch-phrase of 'the harmony between economic development and environmental protection'. China is now confronted with dual pressure both domestically and abroad because of deepening environmental problems. There are growing public's protests and demonstrations in China in response to the spread of damage owing to environmental pollution and ecological deterioration. On the other hand, international society, in particular neighboring countries, regard China as a principal cause of ecological disaster. In the face of this dual pressure, China is presently contemplating a 'recycling economy' that helps sustainable development through the structural reform of industries using too much energy and through more severe law enforcement than now. Therefore, it is desirable to promote regional cooperation more progressively and practically in the direction of building China's ability to solve environmental problems.

• Korean Journal of Animal Reproduction
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• v.23 no.4
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• pp.313-321
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• 1999

The purpose of these study was to investigate the use of a glass micropipette (GMP) as a vessel for vitrification of bovine IVP blastocysts, to compare the post-thaw survival rates of bovine blastocysts frozen in GMP with those frozen in OPS that have been previously investigated, and to improve the hatching rate following vitrification with GMP method. The GMP vessel permits higher freezing and warming rate than the OPS due to the higher heat conductivity of the glass and lower mass of the solution that contains the embryos. Groups of three bovine IVP blastocysts were sequentially placed into vitrification solution before being loaded into either the OPS or GMP vessels and immersed into L$N_2$within 20 to 25 sec. Post-thaw blastocysts were serially washed in 0.25 and 0.15 M sucrose in HM and TCM-199 for each 5 min, respectively, and then cultured in TCM 199 supplemented with 10% FCS for 24 h. The rate of blastocyst re-expanding did not significantly different for OPS (75.9%) and GMP (80.0%) methods (P＞0.05). The hatching rates in OPS (34.1%) and GMP (37.5%) methods were significantly lower than that in control group (54.3%) (P＞0.05). In addition, the rate of blastocyst re-expanding was significantly lower if blastocysts were vitrified in the wide portion of the micropipette rather than the narrow portion of the micropipette (83.3 vs 56.7%) (P＞0.05), even though three blastocysts were loaded per vessel. The hatching rate in 0.05% pronase solution treatment for 30, 60 and 90 see (45.9, 54.7 and 57.5%) were significantly higher than that in control (35.0%), even though there was not significantly different between 30 see and control. These results indicate that both vitrification vessels can provide high survival rates of bovine IVP blastocysts. However, the GMP vessel has the advantage over the OPS, in that the former does not need a cap to protect the vessel from floating after immersion in L$N_2$. The location of the embryos (narrow or wide portion of immersion) were considered to be limiting factors to the viability of bovine IVP embryos. The exposing in 0.05% pronase solution for 60 or 90 see can increase hatching rates of post-thaw bovine IVP blastocysts.

• Journal of Animal Science and Technology
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• v.51 no.1
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• pp.53-60
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• 2009

Thirty one Hanwoo steers were used in a completely randomized design experiment to see the effects of concentrate feeding method (group vs. individual feeding) and age at slaughter (26 vs. 28 months of age) on growth performance, feed intake and carcass characteristics. Steers were randomly assigned to one of four groups, G26 (group feeding slaughtered at 26 months of age), G28 (group feeding slaughtered at 28 months of age), I26 (individual feeding slaughtered at 26 months of age) or I28 (individual feeding slaughtered at 28 months of age). Amount of concentrate were restricted to 1.5% of BW for the growing period and 1.8% of BW for the early fattening period in both groups. For the late fattening period, concentrate were given ad libitum for G26 and G28, but were given up to 1.7% of BW for I26 and I28. Average daily gains were higher in individual feeding groups (I26 and I28) than those in group feeding groups (G26 and G28) for the early fattening period (p<0.05). ADGs were higher in group feeding groups than those in individual feeding groups (p<0.05). Concentrate intake in individual feeding groups tended to be higher compared to that in group feeding groups for the early fattening period, but tended to be higher in group feeding groups compared to that in individual feeding groups for the late fattening period. Feeding method or slaughter age had no significant effects on carcass characteristics, yield grade and quality grade. Shear force and tenderness of longissmus muscle were higher in groups slaughtered at 28 months of age than in groups slaughtered at 26 months of age (p<0.05). Feeding method or slaughter age had no effects on cooking loss, water holding capacity, juiciness, flavor, moisture, protein and fat of longissmus muscle.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.83-88
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• 2016

In this study, previously reported surplus solar energy-related study result and current status of fan coil unit (FCU) for cooling and heating installed in the current sites were briefly examined and then a method to determine the number of FCUs required to recover surplus solar energy was schematically proposed to provide basic data for researchers and technical engineers in this field. The maximum, mean, and minimum outside temperatures during the experiment period were about $28.2^{\circ}C$, $4.4^{\circ}C$, and $-11.5^{\circ}C$, respectively. The horizontal surface solar radiation level outside the greenhouse was in a range of $0.8-20.5MJ{\cdot}m^{-2}$ and mean and total solar radiation were $10.8MJ{\cdot}m^{-2}$ and $1,187.5MJ{\cdot}m^{-2}$. The mean temperature and relative humidity in the greenhouse during the daytime were in a range of 18.8-45.5 and 53.5-77.5%. The total surplus solar energy recovered from the greenhouse during the experiment period was approximately 6,613.4MJ, which could supplement about 6.7% of the total heating energy 98,600.2 MJ. In addition, the number of FCUs installed for heating varies case to case, although similar FCUs are used. Thus, it is necessary to study the installation height, orientation and installation distance as well as the appropriate number of FCUs from the efficient and economical viewpoints. The required numbers of FCUs for surplus solar energy recovery were 8.4-10.9units and 6.1-8.0units based on air mass and circular flow rate that passed through the FCUs. Considering calculation methods and the risks such as efficiency and use environments of FCUs, it was found that about nine units (one unit per $24m^3$ approximately) needed to be installed. The required number of FCUs for surplus solar energy recovery was around one unit per $24m^3$ approximately.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.785-792
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• 2006

The characteristics of alcohol fermentation using sweet persimmon juice were studied in static fermentation in an effort to develop new types of functional wine. The yeast strain Saccharomyces cerevisiae KCCM 12650 was selected for use in the fermentation of sweet persimmon juice. Attempts were made to modify the sweet persimmon juice in order to find suitable conditions for alcohol fermentation. The modified sweet persimmon juice (pH 4.0) that was most suitable for alcohol fermentation contained $24^{\circ}Brix$ of sugar supplemented with sucrose as a carbon source and 0.5 g/L of $(NH_4)_2HPO_4$ as a nitrogen source. After 5 days of fermentation at $25^{\circ}C$, 12.8% of alcohol was produced from the modified juice and its pH was slightly decreased to 3.9. Browning of the wine was observed during storage due to the oxidation of phenolic compounds. The initial browning of 0.08% at $OD_{420}$ after fermentation increased to 0.40 during storage for 11 weeks at room temperature. The addition of $K_2S_2O_5$ was effective in delaying the browning of the wine. The browning of the wine decreased to 0.25 at $OD_{420}$ with the addition of 200 mg/L of $K_2S_2O_5$. The wine produced in this study contained some organic acids such as malic acid (6.82% g/L) and succinic acid (1.40 g/L), some minerals such as $K^+$ (947.8 mg/L) and $Mg^{2+}$ (36.4 mg/L), as well as soluble phenolics (779 mg/L of gallic acid equivalent). Schisandra fruit was added to the sweet persimmon juice during alcohol fermentation in order to improve the sour taste and flavor. The best sensory quality (taste, flavor, and color) was obtained by adding 0.5% schisandra fruit.