• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.545-552
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• 2008

The purpose of this study was to evaluate the influence of sodium ascorbate on microtensile bond strengths of total-etching adhesive system to pulp chamber dentin treated with NaOCl. Pulp chambers of extracted human non-caries permanent molars were treated as follows: group 1, with 0.9% NaCl; group 2, with 5.25% NaOCl; group 3, with 5.25% NaOCl and 10% sodium ascorbate for 1min; group 4, with 5.25% NaOCl and 10% sodium ascorbate for 1 min and 10ml of water; group 5, with 5.25% NaOCl and 10% sodium ascorbate for 5 min; group 6, with 5.25% NaOCl and 10% sodium ascorbate for 5 min and 10ml of water; group 7, with 5.25% NaOCl and 10% sodium ascorbate for 10 min; group 8, with 5.25% NaOCl and 10% sodium ascorbate for 10 min and 10ml of water. Treated specimens were dried, bonded with a total-etching adhesive system (Single bond), restored with a composite resin(Z250) and kept for 24h at 100% humidity to measure the microtensile bond strength. NaOCl-treated group (group 2) demonstrated significantly lower strength than the other groups. No significant difference in microtensile bond strengths was found between NaCl-treated group (group 1) and sodium ascorbatetreated groups (group 3-8). The results of this study indicated that dentin treated with NaOCl reduced the microtensile bond strength of Single bond. Application of 10% sodium ascorbate restored the bond strength of Single bond on NaOCl-treated dentin. Application time of sodium ascorbate did not have a significant effect.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.625-628
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• 2015

POLARBEAR is a ground-based experiment located in the Atacama desert of northern Chile. The experiment is designed to measure the Cosmic Microwave Background B-mode polarization at several arcminute resolution. The CMB B-mode polarization on degree angular scales is a unique signature of primordial gravitational waves from cosmic inflation and B-mode signal on sub-degree scales is induced by the gravitational lensing from large-scale structure. Science observations began in early 2012 with an array of 1.274 polarization sensitive antenna-couple Transition Edge Sensor (TES) bolometers at 150 GHz. We published the first CMB-only measurement of the B-mode polarization on sub-degree scales induced by gravitational lensing in December 2013 followed by the first measurement of the B-mode power spectrum on those scales in March 2014. In this proceedings, we review the physics of CMB B-modes and then describe the Polarbear experiment, observations, and recent results.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.520-527
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• 2008

Purpose: This study was conducted to evaluate the shear bond strength of composite resin to dentin when etched with laser instead of phosphoric acid. Material and methods: Recently extracted forty molars, completely free of dental caries, were embedded into acrylic resin. After exposing dentin with diamond saw, teeth surface were polished with a series of SiC paper. The teeth were divided into four groups composed of 10 specimens each; 1) no surface treated group as a control 2) acid-etched with 35%-phosphoric acid 3) Er:YAG laser treated 4) Er,Cr:YSGG laser treated. A dentin bonding agent (Adapter Single Bond2, 3M/ESPE) was applied to the specimens and then transparent plastic tubes (3 mm of height and diameter) were placed on each dentin. The composite resin was inserted into the tubes and cured. All the specimens were stored in distilled water at $37^{\circ}C$ for 24 hours and the shear bond strength was measured using a universal testing machine (Z020, Zwick, Germany). The data of tensile bond strength were statistically analyzed by one-way ANOVA and Duncan's test at ${\alpha}$= 0.05. Results: The bond strengths of Er:YAG laser-treated group was $3.98{\pm}0.88$ MPa and Er,Cr:YSGG laser-treated group showed $3.70{\pm}1.55$ MPa. There were no significant differences between two laser groups. The control group showed the lowest bond strength, $1.52{\pm}0.42$ MPa and the highest shear bond strength was presented in acid-etched group, $7.10{\pm}1.86$ MPa (P < .05). Conclusion: Laser-etched group exhibited significantly higer bond strength than that of control group, while still weaker than that of the phosphoric acid-etched group.

• The Korean Society of Law and Medicine
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• v.10 no.2
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• pp.253-286
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• 2009

Die $\ddot{a}$mrztliche Behandlung des Patienten durch den Arzt geschieht im Rahmen eines Rechtsverh$\ddot{a}$ltnisses. Das Arzt-Patienten-Rechtsverh$\ddot{a}$ltnis stellt regelm$\ddot{a}$ssig der Arztvertrag oder Behandlungsvertrag dar. Arzt und Patient schliessen einen Arztvertrag ab. Grunds$\ddot{a}$tzlich verbindet der Arztvertrag die Partner pers$\ddot{o}$nlich. Aber minderj$\ddot{a}$hrige Patienten sind gesch$\ddot{a}$ftsunf$\ddot{a}$hig oder in der Gesch$\ddot{a}$ftsf$\ddot{a}$higkeit beschr$\ddot{a}$nkt. Minderj$\ddot{a}$hrige Patienten verm$\ddot{o}$gen also allein grunds$\ddot{a}$tzlich keine wirksamen Willenserkl$\ddot{a}$rungen abzugeben und somit keine wirksamen Arztvertr$\ddot{a}$ge zu schliessen. Arztvertr$\ddot{a}$ge von minderj$\ddot{a}$hrigen Patienten sind nur bei Einwilligung der gesetzlichen Vertreter wirksam. Vom Abschluss des Arztvertrags ist deutlich die Einwilligung zur Behandlung zu unterscheiden. Die Einwilligung ist kein Rechtsgesch$\ddot{a}$ft. Die Einwilligung durch die Eltern erfolgt nur solange der minderj$\ddot{a}$hrige Patient nicht reif genug ist, die Entscheidung selbst zu treffen. Jugendlicher Patient ist z.B. in der Lage, die Einwilligung selbst zu geben, sofern er Wesen, Bedeutung und Tragweite der Behandlung zu verstehen vermag. Der Vorschriften des KBGB zur Gesch$\ddot{a}$ftsf$\ddot{u}$hrung ohne Auftrag gelten, wenn der Arzt einen Bewusstlosen versorgt. Nach $\S$734 KBGB erfolgt die Gesch$\ddot{a}$ftsf$\ddot{u}$hrung ohne Auftrag dann zu Recht, wenn sie dem Interesse und dem wirklichen oder mutmasslichen Willen des Patienten entspricht. Der Patient kann aus einem Ausland stammen. F$\ddot{u}$r ausl$\ddot{a}$ndische Patienten gilt generell das koreanische Recht. Grunds$\ddot{a}$tzlich sollte man einen des Koreanischen nicht m$\ddot{a}$chtigen Ausl$\ddot{a}$nder nach M$\ddot{o}$glichkeit in seiner Sprache aufkl$\ddot{a}$ren und dann den Arztvertrag abschliessen. Aufgrund der Privatautonomie kann jeder Patient frei entscheiden, ob, mit wem und wor$\ddot{u}$ber er einen Arztvertrag abschliesst. Deswegen ist auch der Wille des Anh$\ddot{a}$ngers vom Sekten und abweichenden Lebensauffassung grunds$\ddot{a}$tzlich zu ber$\ddot{u}$cksichtigen. Zum Beispiel handelt der Zeuge Jehovas auf eigene Gefahr, wenn er eine notwendige Behandlung ablehnt. Aber die Freiheit, eine gebotene Behandlung abzulehnen, kann in Konflikt mit dem Schutz des minderj$\ddot{a}$hrigen Patienten gelangen. Sobald die sektiererische oder abweichende Haltung droht, einen minderj$\ddot{a}$hrigen Patienten zu gef$\ddot{a}$hrden, hat das elterliche Sorgerecht einzuschr$\ddot{a}$nken.

• Restorative Dentistry and Endodontics
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• v.29 no.4
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• pp.386-398
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• 2004

Objectives: The purpose of this study was to observe the reaction kinetics and the degree of polymerization of composite resins when cured by different light sources and to evaluate the effectiveness of the blue Light Emitting Diode Light Curing Units (LED LCUs) compared with conventional halogen LCUs. Materials and Methods: First, thermal analysis was performed by a differential scanning calorimeter (DSC). The LED LCU (Elipar Freelight, $320{\;}mW/\textrm{cm}^2$) and the conventional halogen LCU (XL3000, $400{\;}mV/\textrm{cm}^2$) were used in this study for curing three composite resins (SureFil, Z-250 and AEliteFLO). Second. the degree of conversion was obtained in the composite resins cured according to the above curing mode with a FTIR. Third, the measurements of depth of cure were carried out in accordance with ISO 4049 standards. Statistical analysis was performed by two-way ANOVA test at 95% levels of confidence and Duncan's procedure for multiple comparisons. Results: The heat of cure was not statistically different among the LCUs (p > 0.05). The composites cured by the LED (Exp) LCUs were statistically more slowly polymerized than by the halogen LCU and the LED (Std) LCU (p < 0.05). The composite resin groups cured by the LED (Exp) LCUs had significantly greater degree of conversion value than by the halogen LCU and the LED (Std) LCU (p =0.0002). The composite resin groups cured by the LED (Std) LCUs showed significantly greater depth of cure value than by the halogen LCU and the LED (Exp) LCU (p < 0.05).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.2919-2924
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• 2011

The automatic drawer is used to absorb the movement shock and adjust its velocity when it opens and closes. The tube in shock-absorber is the cylindrical case which surrounds its parts and is made of acetal. The purpose of this study is to determine the quality stability of the tube in the shock-absorber in injection molding process. The tube which had been manufactured in the process with 4 cavity cooling unit was used. In this study, the analysis and test are carried out to determine its quality stability. Which are the quality analysis with numerical simulation and performance tests of the tube compared with one of foreign make. It is calculated that the injection press is 87.6 MPa and the deflections in X, Y, Z directions are ranged in 0.07~1.00 mm. When the researched tube is compared with the foreign made tube, the maximum bending compressive load is 231 kgf higher, average axial compressive load is 0.05 kgf higher, and the roughness(Ra) on the inner surface is $0.02\;{\mu}m$. lower. In the result, it is known that the quality of researched tube in injection mold process is stable and its performance is superior.

• Korean Journal of Environment and Ecology
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• v.27 no.3
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• pp.369-380
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• 2013

This study was carried out to provide basic data for conservation management of Pinus densiflora forest and to predict ecological succession tendency by analyzing plant community structure and change of Pinus densiflora community structure for twenty two years in Yongmun-sa (Temple) Valley, Yangpyeong-gun. According to the analysis of actual vegetation, Pinus densiflora community accounted for 51.3% of the total vegetation in the area. Nineteen plots were classified into four community types. The Shannon's species diversity index (H') showed from 0.5110 to 1.3101. There were distributed Pinus densiflora in age from 48 to 89, Quercus serrata in age from 31 to 63, Carpinus laxiflora in age from 26 to 61. According to the analysis of the change for twenty-two years, Pinus densiflora community was maintained or decreased and competitive species (Quercus serrata, Carpinus laxiflora, Carpinus cordata) were increased. The ecological succession tendency was predicted Pinus densiflora community develop into Quercus serrata, lastly into Carpinus laxiflora and Carpinus cordata.

• Journal of Ecology and Environment
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• v.44 no.1
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• pp.8-25
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• 2020

Background: Species of the genera Eucalyptus, Cupressus, and Pinus are the most widely planted tree species in the country in general and in Chilimo dry Afromontane forest in particular. Eucalyptus covers 90% of the total planted forest area in the country. However, only limited information exists in the country regarding aboveground biomass (AGB), belowground biomass (BGB), growth, and yield. This study was conducted to assess the variables on 25 and 30 years of age for three planted species: Cupressus lusitanica, Eucalyptus saligna, and Pinus patula in Chilimo plantation forest, in the Central Highlands of Ethiopia. A two-times inventory was conducted in 2012 and 2017. A total of nine square sampled plots of 400 ㎡ each, three plots under Cupressus lusitanica, 3 Eucalyptus saligna, and 3 Pinus patula were used for data collection. Data on height, diameter, soil, and tree stumps were collected. Percent C, % N, and bulk density was performed following chemical procedure. Results: The aboveground biomass ranged from 125.76 to 228.67 t C ha^-1 and the basal area and number of stems from 3.76 to 25.50 ㎡ ha^-1 and 483 to 1175 N ha^-1, respectively. The mean annual basal area and volume increment were between 0.97 and 1.20 ㎡ ha^-1 year^-1 and 10.79 and 16.22 ㎥ ha^-1 year^-1. Both carbon and nitrogen stock of the planted forest was non-significant among the tree species. Conclusion: The aboveground biomass, growth, and yield significantly varied among the species. Cupressus lusitanica had the highest aboveground biomass, volume, and basal area, while Eucalyptus saligna had the lowest value. To a depth of 1 m, total carbon stored ranged from 130.13 to 234.26 t C ha^-1. The total annual carbon sequestration potential was 12,575.18 t CO₂ eq. Eucalyptus has the highest carbon stock density and growth rate than other species.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.40-54
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• 2017

The mound grave of Korean traditional funeral culture is a unique habitat which is a Zoysiagrass lawn being sustainable in proper management. We phytosociologically described an unusual Zoysiagrass vegetation with Gueldenstaedtia verna by the Zürich-Montpellier School's method and analyzed eco-floristic characteristics. A new association, Gueldenstaedtio-Zoysietum japonicae ass. nov. hoc loco, was identified and subdivided into festucetosum ovinae, typicum, and trifolietosum repensae. The subassociations were distinguished by the difference in species composition resulting from site accessibility and lawn management method. The association was assigned as not only a regional but also a locally-limited vegetation type, which distributes on a particular microhabitat with strong continentality in the Daegu regional subdistrict of Bioclimatological division. The Zoysiagrass vegetation of Korea was considered as a continental type apparently different from the oceanic type of Zoysion japonicae (Miscanthetea sinensis, Caricetalia nervatae). Mound graves in Korea should be acknowledged as a meaningful habitat for the in-situ conservation of biodiversity and phytocoenosen, despite being a secondary grassland of Gueldenstaedtio-Zoysietum japonicae.

• Journal of the Korean Geophysical Society
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• v.3 no.4
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• pp.269-280
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• 2000

Rail vibration in city zone is becoming a serious environmental problem. In order to make a reduction plan for rail vibration, the research was conducted in which many experiments to measure actual rail vibration along the railroad through the central Deajeon area. A digital vibration level meter was used to measure rail vibration. Vibration levels of Z-axis were measured at every second for the duration of the train passing. The measuring station was placed at every 5m for the distance of 55m. A total of 353 different sets of vibration level were obtained. The signals were processed to get $L_{10}$ value and analyzed in terms of distance, train velocity, and number of trains. As a result, it has been found that rail vibration exceed the allowable vibraton limit of 60 dB, at the point of 25 m far from the railroad center, which is regulated by the las of vibration and noise. Train velocity was found to affect a little for vibration level within the zone. It was also found that a trench installed along a railroad could reduce vibration level up to approximately 10 percent. A model test was conducted to investigate the influence of the location and size of trench, on the transfer of vibration. A heavy steel ball was used to generate vibrations. On the basis obtained from this study, it could be concluded that the application of distance-attenuation and the installment of a trench along railroad could be applied as a reduction plan for rail vibration. Because limitions might exist to depend on the effect of distance attenuation, trenchs excavated along a railroad might be suggested as the most efficient solution to reduce railroad vibration.