• Asian-Australasian Journal of Animal Sciences
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• v.33 no.11
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• pp.1848-1857
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• 2020

Objective: An experiment was designed to determine if behaviour traits expressed by twin- and triplet-bearing lambs and their dams at 3 to 18 hours of age (after the immediate ewe-lamb bonding had occurred) were associated with lamb survival to weaning. Methods: The behaviour of twin and triplet lambs and their dams was assessed in the paddock at 3 to 18 hours after birth. Observations were made of the number of high- and low-pitched bleats, time to stand, make contact with dam, suck from dam and follow dam were recorded for each lamb. The maternal behaviour score of each dam was assessed. A random sub-sample of lambs were assessed during a maternal-recognition test at 12 or 24 hours of age. Traits included time spent standing, sitting, walking, time taken to reach the ewes and time spent with the ewes as well as the number of high- and low-pitched bleats emitted by the lamb. Results: In the paddock, for each additional second required for twin-born lambs to follow their dam, lambs were 1.004 (95% confidence interval [CI] 1.000 to 1.008) times more likely to survive to weaning (p<0.05). The opposite relationship, however, was seen in triplet lambs. For each additional second required for triplet-born lambs to follow their dam, lambs were 0.996 (95% CI 0.993 to 0.999) times as likely to survive to weaning (p<0.05). During the maternal recognition test, twin-born lambs were 0.989 (95% CI 0.979 to 1.000) times as likely to survive to weaning for every additional second they took to reach the contact zone (p<0.05). Similarly, triplet-born lambs were 0.994 (95% CI 0.989 to 0.999) as likely to survive for every additional second they took to reach their dam (p<0.05). Conclusion: All ewe behaviours and the majority of lamb paddock and test behaviours were not associated with the survival of twin- or triplet-born lambs and, therefore, are of little use as indicators of lamb survival to weaning.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.426-437
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• 2005

Statement of problem : Although zirconium oxide ceramics are more and more commonly used in restorative dentistry, for many clinical applications only limited data can be found in the literature. However it is quite clear that hydrofluoric acid etching is impossible with zirconia ceramics. Therefore, other bonding techniques are required in order to lute these materials adhesively. Purpose : The purpose or this study was to evaluate the effects of surface treatments on shear bond strengths between two resin cements and a zirconia ceramic. Materials and methods : Experimental industrially manufactured yttrium-oxide-partially-stabilized zirconia ceramic discs (Adens, Korea) were used for this study. The ceramic specimens divided into five experimental groups and a control group (as received). Five surface treatments were studied 1) sandblasting with 110$\mu$m $Al_2O_3$ at 3 bars pressure 13 seconds at a distance of 10 mm, 2) flame-treated with the Silano-Pen for 5 $s/cm^3$, 3) grinding with a diamond bur. 4) sandblasting + Silano-Pen treatment, 5) diamond bur preparation + Silano-Pen treatment. Acrylic plastic tube (5 mm in height and 3 mm in diameter) were filled with composite to fabricate composite cylinders The composite cylinders were bonded to the ceramic specimens with either Superbond C&B or Panavia F resin luting agents. All cemented specimens were tested under shear loading until fracture on universal testing machine at a crosshead speed 1mm/min; the maximum load at fracture was recorded. Sheat bond strength data were analyzed with oneway analysis of variance and Tukey HSD tests (P<.05). Treated ceramic surfaces and fracture surfaces after shear testing were examined morphologically using scanning electron microscope. Results: Ceramic surface treatment with Silano-Pen after sandblasting improved the bond strength of Superbond C&B resin cement. Supevbond C& B resin cement at Silano-Pen aiker sandblasting($27.4{\pm}3.8MPa$) showed statistically higher shear bond strength than the others. Conclusion: Within the limitation of this study, Superbond C& &B resin cement are suitable for cementation of zirconia ceramics and flame-treated with the Silano-Pen after sandblasting is required to enhance the bond strength.

• Polymer(Korea)
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• v.33 no.1
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• pp.79-83
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• 2009

Thin electric insulation layers were coated on aluminum plates and aluminum condenser cases by plasma polymerization of HMDSO+$O_2$. Electric resistances of the films were higher than 1.0 M$\Omega$ if they are thicker than 0.5 ${\mu}m$ independently of the type of films but their surface morphologies and adhesion strengths were dependent on the process conditions. Deposition rate and adhesion strength of the films were dependent on $O_2$/HMDSO flow ratio and discharge power. The best result was obtained at $O_2$/HMDSO flow ratio of 4 and discharge power of 60 W. Adhesion strength could also be highly improved if aluminum was pre-treated in boiling water for 30 min through the formation of Al-O-Si bonding between the film and the aluminum surface. The coated films showed excellent chemical and thermal resistances.

• Journal of Korean Dental Science
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• v.2 no.2
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• pp.5-11
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• 2009

Objectives : This study investigated the hypothesis that the dentin bond strength of self-etching adhesives (SEAs) may be improved by applying a coat of hydrophobic, neutral adhesive resin in addition to SEA. Method and Materials : The bond strengths of two SEAs - Experimental SEA (EX) and Adper Prompt (AP) - were measured with three bonding protocols. The D/E resin of All-Bond 2 was applied as the hydrophobic, neutral adhesive. Clearfil SE Bond (SE, self-etching primer system) and All-Bond 2 (AB, total etching system) were used as references. The following protocols were used: (1) EX1 (EX 1 coat); (2) EX2 (EX 2 coats); (3) EX+ (EX 1 coat + D/E resin); (4) AP1 (AP 1 coat); (5) AP2 (AP 2 coats); (6) AP+ (AP 1 coat + D/E resin); (7) SE (SE primer + SE bond); (8) SE+ (SE primer + D/E resin); (9) AB (etching + AB primer + D/E resin). Filtek Z250 composite resin was built up and the microtensile bond strength (MTBS) values of the specimens were compared. The fractured surfaces were observed using SEM. Results : When SEA was used as self-etching primer and hydrophobic, neutral adhesive was applied as well, MTBS was significantly higher than that when either one coat or two coats of SEA only were used (p < 0.05). Conclusion : The hydrophobic, neutral adhesive improved the integrity of the bonded interface obtained with SEA.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3135-3141
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• 2013

This study derives the optimal conditions for design parameters of clinch stud with high torque resistance and bonding force by using FE simulation and Taguchi method. Maximum forming load and filled rate of material are considered as objective functions. Height and depth of groove with diameter and depth of lobe are chosen as design parameters. These control factors and the friction considered as noise factor are combined by orthogonal array. Forming load and filled rate are evaluated through the simulation. Simulation results are analyzed by using the ratio of signal to noise through Taguchi method. From these results, their optimal combination conditions are proposed. In the order of the most important parameter which affects filled rate, there are the height of lobe, the height of groove, the radius of lobe and the depth of groove.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.2
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• pp.49-53
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• 2018

Recently, technologies for integrating various devices such as a flexible device, a transparent device, and a MEMS device have been developed. The key processes of heterogeneous device manufacturing technology are chip or wafer-level bonding process, substrate grinding process, and thin substrate handling process. In this study, the effect of Si substrate grinding process on the electrical properties of tin oxide thin films applied as transparent thin film transistor or flexible electrode material was investigated. As the Si substrate thickness became thinner, the Si d-spacing decreased and strains occurred in the Si lattice. Also, as the Si substrate thickness became thinner, the electric conductivity of tin oxide thin film decreased due to the lower carrier concentration. In the case of the thinner tin oxide thin film, the electrical conductivity was lower than that of the thicker tin oxide thin film and did not change much by the thickness of Si substrate.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.5
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• pp.206-210
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• 2018

Two kinds of bioactive glass were coated on the Ti6Al4V alloy by the enameling technique. In order to reduce the thermal stress due to the difference in expansion coefficient with the alloy with the secondary coating forming hydroxyapatite, the difference in expansion coefficient between the alloy and the two glasses was adjusted at $2{\times}10^{-6}/^{\circ}C$ intervals. FE-SEM and EDS analysis showed that good adhesion was formed between the Ti6Al4V alloy and the primary coating by diffusion bonding. After immersion in SBF solution, it was confirmed from FT-IR that hydroxycarbonate apatite formed in the secondary coating was not different from bulk bioactive glass.

• Restorative Dentistry and Endodontics
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• v.27 no.6
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• pp.622-631
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• 2002

To understand the recent characteristics of the papers published in the Journal of Korean Academy of Conservative Dentistry(JKACD), All the papers in the JKACD of 1992 to 2001 were analyzed. A total of 513 papers were classified according to its type, fold and subject of the study, school and the number of authors, references, and written language. The results were as follows ; 1 According to the type of the paper, 506(98.6%) were original articles, 3(0.6%) were review articles, and 4(0.8%) were case reports. 2. Anual proportion of papers in the fold of operative dentistry was similar to that of endodontics 3. In the field of operative dentistry, esthetic restorative materials and bonding to tooth constituted major subjects of the studies. In the field of endodotics, pulp biology was prominent and canal shaping, endodontic microbiology and canal obturation were steadily reported. 4. According to author's school, similar number of papers were published in the field of operative den tistry and endodontics in general. However, some schools showed preponderances. 5. Most studies were done by two or more authors. Studies published by two authors were most 6. Fifty(9.7%) papers were done in collaboration with workers of the other field. 7. Average number of references cited in the papers was 41.2, including domestic references of 1.8. 40.7% of the papers was shown to cite no domestic papers at all. 8. Twenty-eight(5.5%) papers were written in English, with increasing ratio.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.2
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• pp.133-141
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• 2004

Statement of problem : Porcelain restorations are widely used in restorative dentistry with a high degree of general success. However, porcelain is brittle and may fracture intraorally. Sometimes a repair may be attempted using composite resin and bonding system available. Color stability of porcelain repair resins affects esthetics and prognosis of prosthesis, so that provides important criteria for the choice of porcelain repair resins. Purpose : The purpose of this study was to investigate the color stability of composite resins used widely as porcelain repair system. Materials and method : Composite resins used for this study were Carisma(Kulzer, Germany), Tetric ceram(Ivoclar, Liechtenstein), Filtek Z250(3M, USA), and Arabesk Top(VOCO, Germany). Thirty disc-shaped specimens($10{\times}2mm$) were fabricated from each composite resin. Color changes of specimens after treatment using thermocycling system(KD-TCS30, Kwang-duk F.A. Korea) and after immersion in methylene blue(0.05% by Wt) were measured with colorimeter(Model Tc-6Fx, Tokyo Denshoku Co.) and obtained data were analyzed. Results and Conclusion: The results obtained from this study were as fo11ows. 1. The color change of Filtek Z250 was lesser than those of Tetric ceram and Arabesk Top after thermocycling (12000 times). 2. All of the composite resins in this study showed increase of color change according to increase of thermocycling frequency. 3. After treatment with methylene blue, the color change of Arabesk Top was greater than those of Carisma and Tetric ceram, and Tetric ceram was more stable than others.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.511-516
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• 2013

The thickness and deflection of melting parts of the glass edge reach the biggest effect on the intensity and thermal insulation performance. During the sealing process using a hydrogen mixed gas torch, the thickness and the deflection effect of the edge part are affected by process parameters. In order to analyze the correlative relationship of the thickness prediction and the deflection of the edge part according to the process parameters, data was obtained by conducting sealing experiments. The main effects and interaction effects of process parameters for the thickness and the shape of the glass edge parts were analyzed through the design of experiment. A mathematical experiment equation that can predict the thickness and deflection of the edge part according to the process parameters was developed by conducting multiple regression equations.