• Title/Summary/Keyword: DC21

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In vivo wear determination of novel CAD/CAM ceramic crowns by using 3D alignment

  • Aladag, Akin;Oguz, Didem;Comlekoglu, Muharrem Erhan;Akan, Ender
    • The Journal of Advanced Prosthodontics
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    • v.11 no.2
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    • pp.120-127
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    • 2019
  • PURPOSE. To determine wear amount of single molar crowns, made from four different restoratives, and opposing natural teeth through computerized fabrication techniques using 3D image alignment. MATERIALS AND METHODS. A total of 24 single crowns (N = 24 patients, age range: 18 - 50) were made from lithium disilicate (IPS E-max CAD), lithium silicate and zirconia based (Vita Suprinity CAD), resin matrix ceramic material (Cerasmart, GC), and dual matrix (Vita Enamic CAD) blocks. After digital impressions (Cerec 3D Bluecam, DentsplySirona), the crowns were designed and manufactured (Cerec 3, DentsplySirona). A dualcuring resin cement was used for cementation (Variolink Esthetic DC, Ivoclar). Then, measurement and recording of crowns and the opposing enamel surfaces with the intraoral scanner were made as well as at the third and sixth month follow-ups. All measurements were superimposed with a software (David-Laserscanner, V3.10.4). Volume loss due to wear was calculated from baseline to follow-up periods with Siemens Unigraphics NX 10 software. Statistical analysis was accomplished by Repeated Measures for ANOVA (SPSS 21) at = .05 significance level. RESULTS. After 6 months, insignificant differences of the glass matrix and resin matrix materials for restoration/enamel wear were observed (P>.05). While there were no significant differences between the glass matrix groups (P>.05), significant differences between the resin matrix group materials (P<.05) were obtained. Although Cerasmart and Enamic were both resin matrix based, they exhibited different wear characteristics. CONCLUSION. Glass matrix materials showed less wear both on their own and opposing enamel surfaces than resin matrix ceramic materials.

Volumetric analysis of normal condyles and those with disc displacement with reduction in the Indonesian population: A CBCT study

  • Nawawi, Azkya Patria;Rikmasari, Rasmi;Kurnikasari, Erna;Oscandar, Fahmi;Lita, Yurika Ambar
    • Imaging Science in Dentistry
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    • v.52 no.1
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    • pp.103-108
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    • 2022
  • Purpose: Disc displacement can cause resorption of the head of the condyle and affect its volume. This study analysed the volume of normal condyles and those with disc displacement with reduction (DDR) in cone-beam computed tomography (CBCT) scans from the Indonesian population. Materials and Methods: This study analysed 56 condyles (26 normal and 30 with DDR) from patients who visited the Oral and Maxillofacial Radiology Unit after being referred from the Prosthodontics Unit at Dental Hospital Universitas Padjadjaran from December 2020 to February 2021. Samples were divided into 2 groups (normal and DDR left and right-side condyles) based on the DC/TMD Axis 1 form through the clinical examination results. Both sample groups were exposed to CBCT radiation. The CBCT imaging results in the Digital Imaging and Communications in Medicine format were exported to the open-source ITK-SNAP format to determine condyle volume. Volumetric data from the cortical and trabecular areas of the right or left side condyles were arranged by sex. The independent t-test was used to determine the significance of differences with IBM SPSS version 21.0. Intra- and inter-observer reliability and validity were tested before determining the volume of the condyles. Results: Normal condyles and DDR condyles showed significant differences in volume (P<0.05). Significant differences were also seen in cortical (P=0.0007) and trabecular (P=0.0045) volumes. There was a significant difference in condylar volume based on sex. Conclusion: The normal condyle volume was significantly different from the DDR condyle volume in both sexes.

Effect of Ag interlayer on the optical and electrical properties of ZnO thin films (Ag 중간층 두께에 따른 ZnO 박막의 광학적, 전기적 특성 연구)

  • Kim, Hyun-Jin;Jang, Jin-Kyu;Choi, Jae-Wook;Lee, Yeon-Hak;Heo, Sung-Bo;Kong, Young-Min;Kim, Daeil
    • Journal of the Korean institute of surface engineering
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    • v.55 no.2
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    • pp.91-95
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    • 2022
  • ZnO single layer (60 nm thick) and ZnO with Ag interlayer (ZnO/Ag/ZnO; ZAZ) films were deposited on the glass substrates by using radio frequency (RF) and direct current (DC) magnetron sputter to evaluate the effectiveness of Ag interlayer on the optical visible transmittance and the conductivity of the films. In the ZAZ films, the thickness of ZnO layers was kept at 30 nm, while the Ag thickness was varied as 5, 10, 15 and 20 nm. In X-ray diffraction (XRD) analysis, ZnO films show the (002) diffraction peak and ZAZ films also show the weak ZnO (002) peak and Ag (111) diffraction peak. As a thickness of Ag interlayer increased to 20 nm, the grain size of the Ag films enlarged to 11.42 nm and the optical band gap also increased from 4.15 to 4.22 eV with carrier concentration increasing from 4.9 to 10.5×1021 cm-3. In figure of merit measurements, the ZAZ films with a 10 nm thick Ag interlayer showed the higher figure of merit of 4.0×10-3 Ω-1 than the ZnO single layer and another ZAZ films. From the experimental result, it is assumed that the Ag interlayer enhanced effectively the opto-electrical performance of the ZAZ films.

Effects of Platycodi Radix ethanol extract on ovalbumin-induced allergic responses in mice (난알부민 유도 알레르기 면역반응에 대한 길경(桔梗)에탄올추출물의 효능 연구)

  • Jung, Jin Ki;Kang, Seok Yong;Kim, Jinwoong;Lee, Sang Kook;Park, Yong-Ki
    • The Korea Journal of Herbology
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    • v.27 no.6
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    • pp.123-129
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    • 2012
  • Objectives : Allergy has been described as an inflammatory with hypersensitivity resulting from seasonal or perennial responses to specific allergens. The root of Platycodon grandiflorum (Jacq.) A. DC.(Platycodi Radix; Campanulaceae) has been traditionally used to treat chronic diseases such as bronchitis, asthma, pulmonary tuberculosis, inflammation and hyperlipidemia. In this study, we examined the effect of 70% ethanol extract of Platycodi Radix (PR-E) on ovalbumin (OVA)-induced airway inflammation in mice. Methods : Mice were sensitized and challenged by OVA inhalation to induced chronic airway inflammation, and then were intragastrically administered PR-E extract at doses of 50 and 200 mg/kg/day from days 21 to 30 consecutively. The levels of allergic mediators such as histamine, OVA-specific immunoglobulin (Ig) E, and cytokines such as IL-4 and IFN-${\gamma}$ were measured in the sera of mice by ELISA. The histological change of lung tissue was observed by hematoxylin and eosin (H&E) staining. Results : PR-E extract significantly decreased the serum levels of histamine, OVA-specific IgE, and Th2 cytokine, IL-4 compared with those in the OVA-induced group. PE-E extract significantly increased the serum level of Th1 cytokine, IFN-${\gamma}$. Based on lung histopathological studies, inflammatory cell infiltration and mucus hypersecretion were inhibited by PE-E extract administration compared to that in the OVA-induced group. Conclusions : These findings indicate that PE-E extract may be useful as an adjuvant therapy for the treatment of bronchial asthma.

The Crystal Structure of Cholesteryl Carbonates (콜레스테롤 카보네이트 결정구조에 관한 연구)

  • 박영자;신정미
    • Korean Journal of Crystallography
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    • v.7 no.1
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    • pp.8-19
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    • 1996
  • Cholestryl Methyl and Propyl Carbonate(CH3OCOOC27H45, C3H7OCOOC27H45) are monoclinic, space group P21, with a=17.014(1), b=7.682(1), c=10.612(1)Å, β=103.05(1)°, Z=2, V=1351.16Å3, Dc=1.09 g/cm3 for methyl carbonate, and with a=13.683(1), b=11.864(2), c=18.904(2)Å, β=106.30(1)°, Z=4, V=2945.4Å3, Dc=1.06 g/cm3, Dm=1.06 g/cm3 for propyl carbonate. The intensity data were collected on an Enraf-Nonius CAD-4 diffractometer with a graphite monochromated Cu-Kα radiation. The structure was solved by direct methods and refined by full matrix least-squares methods. The final R factor was 0.051 for 2323 observed reflections for methyl carbonate and 0.074 for 3323 observed reflections for propyl carbonate. Compared with other cholesteryl derivatives, the cholesteryl ring and tail region of the molecules are normal. The molecules are stacked in clearly separated layers. At center of the layer, there are cholesteryl-C(17) side chain interactions. The interface region between layers is occupied by the loosely packed methyl carbonate chains. The structure of cholesteryl propyl carbonates have two propyl carbonates have two molecules(A, B) that are not related by crystal symmetry and have their tetracyclic system almost parallel to each other. Cholesteryl-cholesteryl interactions between symmetry related A-molecules, and cholesteryl-C(17) side chain interactions between symmetry related B-molecules occur at the center of the layers and these molecules stack along 2₁ screw axes. There are also C(17)chain-carbonate chain and C(17)chain-C(17)chain interactions in the interface region between layers. There is efficient packing between cholesteryl ring systems in propyl carbonates. Temperature ranges of cholesteric mesophases of cholesteryl alkyl cargonates are narrow for methyl, pentyl and hexyl carbonates, and rather broader for ethyl and propyl carbonates. Cholesteryl-isotropic transitions change very little with chain length.

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Skewed Inheritance of EST-SSR Alleles in Reciprocal Crosses of Cut Roses (절화장미 품종간 정역교배에 있어서 EST-SSR 마커의 유전)

  • Kim, Jin-Ki;Ahn, Dong-Chun;Oh, Hye-Jeong;Kim, Kwang-Hwan;Choi, Young-Mi;Oh, Seung-Yong;Kang, Nam-Jun;Jeong, Byoung-Ryong;Kim, Zhoo-Hyeon;Park, Young-Hoon
    • Horticultural Science & Technology
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    • v.28 no.4
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    • pp.618-626
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    • 2010
  • Matroclinal inheritance of morphological characters in interspecific crosses of Rosa spp. can be influenced by cytoplasmic inheritance, apomixis, and asynaptic heterogamy. In asynaptic heterogamy, which is often observed from interspecific crosses of Rosa sect. $Caninae$, the polyploidy of the seed parent (especially for 5x=35) is recovered in the progeny through the pollens that include only a set of bivalents (x=7) and egg cells that contain a set of bivalents (x=7) and other univalents (3x=21). In this study, we investigated the causes of matroclinal offsprings observed from reciprocal crosses of tetraploid cut rose cultivars ($Rosa$ $hybrida$ L.) by analyzing EST-SSR marker distribution in the progeny populations. From EST-SSR marker analysis of eight offsprings per six reciprocal crosses among six cultivars, cases of cytoplasmic inheritance were not observed. Apomixis was also very rare as compared to the reports on interspecific crosses of sect. $Caninae$; only one apomitic plant was identified from the cross 'Redtem' ${\times}$ 'Red Sandra'. Although a clear-cut pattern of asynaptic heterogamy was not found, cultivar-specific marker transmission skewed to seed parent in four cultivars implied that genetic inheritance can be highly influenced by the seed parent depending on crosses among cut rose cultivars; especially, 10 out of 11 alleles specific to 'Yellow King' distributed in progenies at higher ratios when the cultivars were crossed as the seed parent.

A Study on PWM Speed Controller for Long line Fishing Motor (어로 작업용 연승기 전동기의 PWM 속도제어기에 관한 연구)

  • Vuong, Duc-Phuc;Bae, Cherl-O;Ahn, Byong-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.1
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    • pp.97-102
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    • 2015
  • The long line fishing machine is combined with motor and two disc rollers has used on the small size fishing-boat under 1 ton located in near Jeollanam-do seaside. The long line fishing motor is controlled only one direction because the fishing line is loaded heavily at pulling up. On this paper we made the long line fishing 400W power motor controller which it was usually applied under 1 ton fishing boat, and designed the controller using PWM chip, Half bridge driver and MOSFET for one direction motor control. Furthermore some user convenience devices were added like battery indicator and safety protection circuit for battery overdischarge and battery source wire mismatch connection. So we protected the battery from overdicharging when the battery voltage was below 11.5V and fishermen didn't need to worry about source lines misconnection anymore. We confirmed the test version of controller was the good working condition at land and sea.

Research on Broadband Millimeter-wave Cascode Amplifier using MHEMT (MHEMT를 이용한 광대역 특성의 밀리미터파 Cascode 증폭기 연구)

  • Baek, Yong-Hyun;Lee, Sang-Jin;Baek, Tae-Jong;Choi, Seok-Gyu;Yoon, Jin-Seob;Rhee, Jin-Koo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.4
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    • pp.1-6
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    • 2008
  • In this paper, millimeter-wave broadband MHEMT (Metamorphic High Electron Mobility Transistor) cascode amplifiers were designed and fabricated. The $0.1{\mu}m$ InGaAs/InAlAs/GaAs MHEMT was fabricated for cascode amplifiers. The DC characteristics of MHEMT are 670 mA/mm of drain current density, 588 mS/mm of maximum transconductance. The current gain cut-off frequency($f_T$) is 139 GHz and the maximum oscillation frequency($f_{max}$) is 266 GHz. To prevent oscillation of the designed cascode amplifiers, a parallel resistor and capacitor were connected to the drain of common gate device. By using the CPW (Coplanar Waveguide) transmission line, the cascode amplifier was designed and matched for the broadband characteristics. The designed amplifier was fabricated by the MHEMT MMIC process that was developed through this research. As the results of measurement, the amplifier was obtained 3 dB bandwidth of 50.37 GHz between 20.76 to 71.13 GHz. Also, this amplifier represents the S21 gain with the average 7.07 dB gain in bandwidth and the maximum gain of 10.3 dB at 30 GHz.

Chromaticity(b*), Sheet Resistance and Transmittance of SiO2-ITO Thin Films Deposited on PET Film by Using Roll-to-Roll Sputter System (롤투롤시스템을 이용하여 PET 필름위에 제조된 SiO2-ITO 박막의 색도(b*), 면저항과 투과도 연구)

  • Park, Mi-Young;Kang, Bo-Gab;Kim, Jung-Soo;Kim, Hye-Young;Kim, Hu-Sik;Lim, Woo-Taik;Choi, Sik-Young
    • Korean Journal of Materials Research
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    • v.21 no.5
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    • pp.255-262
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    • 2011
  • This paper has relatively high technical standard and experimental skill. The fabrication of TCO film with high transparency, low resistance and low chromaticity require exact control of several competing factors. This paper has resolved these problems reasonably well, thus recommended for publication. Indium tin oxide(ITO) thin films were by D.C. magnetron roll-to-roll sputter system utilizing ITO and $SiO_2$ targets of ITO and $SiO_2$. In this experiment, the effect of D.C. power, winding speed, and oxygen flow rate on electrical and optical properties of ITO thin films were investigated from the view point of sheet resistance, transmittance, and chromaticity($b^*$). The deposition of $SiO_2$ was performed with RF power of 400W, Ar gas of 50 sccm and the deposition of ITO, DC power of 600W, Ar gas of 50 sccm, $O^2$ gas of 0.2 sccm, and winding speed of 0.56m/min. High quality ITO thin films without $SiO_2$ layer had chromaticity of 2.87, sheet resistivity of 400 ohm/square, and transmittance of 88% and $SiO_2$-doped ITO Thin film with chromaticity of 2.01, sheet resistivity of 709 ohm/square, and transmittance of more than 90% were obtained. As a result, $SiO_2$ was coated on PET before deposition of ITO, their chromaticity($b^*$) and transmittance were better than previous results of ITO films. These results show that coating of $SiO_2$ induced arising chromaticity($b^*$) and transmittance. If the thickness of $SiO_2$ is controlled, sheet resistance value of ITO film will be expected to be better for touch screen. A four point probe and spectrophotometer are used to investigate the properties of ITO thin films.

A Study on the Volatile Constituents of the Water Dropwort (Oenanthe javanica DC) - according to extraction methods, parts and heating methods - (미나리의 향기성분에 관한 연구 -추출방법, 부위별 및 열처리방법에 따라-)

  • 이행재;고무석;최옥자
    • Korean journal of food and cookery science
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    • v.11 no.4
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    • pp.386-395
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    • 1995
  • This study was carried out to investigate the volatile constituents change according to extraction methods, parts and heating methods. The research results are as follows: 23 kinds of components were extracted by steam distillation method; 8 by head space method; 16 by ether extraction method; 9 by Tenax-GC. This fact indicated that volatile constituents differ depending upon the extracting method. When the volatile constituents were extracted by steam distillation method and analyzed by GC-MSD, the content of the volatile constituents was 41.71 mg% in the stem and 85.37 mg% in the leaf. A total of 23 components - 14 kinds of hydrocarbon, 5 of aldehyde, 4 of alcohol- were detected in the stem. A total of 31 components - 21 kinds of hydrocarbon, 5 of aldehyde, 4 of alcohol and 1 of ester were detected in the leaf. The leaf had comparatively more varied volatile constituents than the stem. In the stem, the octanal content was highest and the contents of limonene, sabinene, -terpinene and -myrcene were higher; in the leaf, the content of octanal was highest and the contents of isobicyclogermacrene, limonene, -farnesene, undecaethiol, -terpinene, sabinene, elemene, -myrcen were higher. These were the major volatile constituents of the water d.opwort. The volatile constituent formation changed as the water dropwort was heated. The volatile constituents of the water dropwort heated in 1000 $m\ell$ were the most similiar to those of the raw water dropwort, and volatile constituent content was highest.

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