• Restorative Dentistry and Endodontics
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• 제15권1호
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• pp.97-105
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• 1990

When conventional root canal treatment is failed or contraindicated, retrograde root canal filling following apicoectomy is a valuable procedure, aimed at hermetically sealing the root canal against leakage of irritants from the canal into the periapical tissue. In this in vitro investigation, to analyze apical microleakage electrochemically in teeth with different retrograde filling materials and preparation types, single - rooted tooth was cut 2mm from the apex and each Class I and Slot preparation was prepared. Experimental groups : Group 1. Amalgam filling with cavity varnish in Class I preparation Group 2. Scotchbond 2+Silux filling in Class I preparation Group 3. Gutta percha filling with ZOE cement in Class I preparation Group 4. Amalgam filling with cavity varnish in Slot preparation Group 5. Scotchbond 2+Silux filling in Slot preparation Each specimens was immersed in 1% solution of KCl, and applied a potential of 9V external power supply. Measurements of the current flow were obtained at 1, 2, 3, 7, 9, 12, 14, 18, 21, 25 and 28 day after immerson. Marginal microleakage were compared and evaluated. The results were as follows ; 1. The group filled with composite resin with dentin bonding agent shows lower apical microleakage value than the group filled with amalgam following varnish application (P<0.01). 2. In the group filled with gutta percha, apical microleakage value was the hightest 3. There was no significant difference between Class I cavity and Slot type cavity regardless of the used materials.

• International Journal of Ocean System Engineering
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• 제1권3호
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• pp.136-143
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• 2011

In this paper, three-dimensional free-surface flows are simulated by using two different numerical methods, the constrained interpolation profile (CIP)-based and finite volume (FV)-based methods. In the CIP-based method, the governing equations are solved on stationary staggered Cartesian grids by a finite difference method, and an immersed boundary technique is applied to deal with wave-body interactions. In the FV-based method, the governing equations are solved by applying collocated finite volume discretization, and body-fitted meshes are used. A free-surface boundary is considered as the interface of the multi-phase flow with air and water, and a volumeof-fluid (VOF) approach is applied to trace the free surface. Among many variations of the VOF-type method, the tangent of hyperbola for interface capturing (THINC) and the compressive interface capturing scheme for arbitrary meshes (CICSAM) techniques are used in the CIP-based method and FV-based method, respectively. Numerical simulations have been carried out for dam-breaking and wave-body interaction problems. The computational results of the two methods are compared with experimental data and their differences are observed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권10호
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• pp.485-491
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• 2006

This paper describes that the distribution of electromagnetic field occurred by PD(Partial Discharge) pulse was calculated with simulation program and characteristics of calibration and PD pulses measured with folded dipole types sensors were analyzed. As the distribution of electromagnetic field in simulation was very random the wide band measuring methods were good. Therefore three folded dipole antenna types sensors which had different their widths were designed and made. The signal according to direction and distance between sensor and pulse source in these sensor was measured and the spectrum of surface PD were acquired in the experiment of model transformer. In this result the characteristics of sensor which had middle width was better than others and the main spectrum of PD signals in surface discharge were existed in around 220MHz, 320MHz and from 450MHz to 750MHz.

• 대한조선학회논문집
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• 제56권6호
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• pp.541-549
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• 2019

In the present study, we investigated planing forces of supercavitated bodies by using the supercavitation shape produced by the disk type cavitator. The cavity shapes are observed to find the immersion draft and planing angle when the stern of the supercavitated body is partially immersed in the water. To make the planing the angle-of-attack (AOA) of the supercavitated body is varied statically against the main flow and the planing tests are carried out for different body shapes that are changed systematically. The drag, lift and pitch moment acting on the body are measured to understand the relation between the planing force and the immersion draft of the supercavitated body. It is found that the planing force increased in general linearly with the immersion draft ratio and the planing angle is certainly not proportional to the immersion draft ratio.

• Restorative Dentistry and Endodontics
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• 제26권6호
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• pp.492-498
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• 2001

The purpose of this study was to evaluate four different composite resins in vitro for microleakage in Class II box type restorations that have gingival margins apical to the cementoenamel junction. Forty caries free extracted human molars were used in this study. The Class II cavities were prepared 1.0mm below cementoenamel junction with a #701 carbide bur. The teeth were randomly divided into four groups, each group comprising 20 treated cavities according to adhesives and filling materials ; Group 1: Scotchbond Multipurpose/Z 100. Group 2: Ariston Liner/Ariston pHc, Group 3: One Step/Pyramid, Group 4: Prime & Bond NT/SureFil. To simulate the clinical situation during restoration placement, a restoration template was fabricated and composite resin was filled using a three sited light-curing incremental technique. The specimens were stored in the 100% humidity for 7 days prior to thermocycling. The specimens were immersed in 2% methylene blue dye solution for 24 hours and then embeded in transparent acrylic resin and sectioned mesiodistally with a diamond wheel saw. The degree of marginal leakage was scored under the stereomicroscope($\times$20) and the data were analyzed by Kruskal Wallis test and Mann Whitney test. (omitted)

• Restorative Dentistry and Endodontics
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• 제17권1호
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• pp.181-190
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• 1992

The purpose of this study was to estimate the contents of the residual monomers, such as Bis-GMA and TEGDMA. In this study, materials used were six kinds of anterior and posterior visible light-cured resins. Resins were placed in disk-shaped Teflon mold (8.5mm in diameter, 2.0mm in thickness), and cured for 20 seconds with visible light source attached wide diameter lightguide. The specimens were immersed in 10ml ethanol and stored for 5 days at $37^{\circ}C$. The concentration of residual monomers in eluate solution was analysed by HPLC, and the following results are obtained. 1. The residual Bis-GMA and TEGDMA were detected in all materials used, and the ranges of quantity of the residual Bis-GMA was 0.101-1.236 wt% and that of TEGDMA was 0.230-5.794 wt%.2. The contents of residual TEGDMA was detected higher than that of residual Bis-GMA (P < 0.01). 3. The content of residual monomers was detected to be highest in Bis-Fil M as microfilled type. 4. In most of the materials used, there was no significant difference in the contents of residual monomers between anterior and posterior light-cured resins.

• Corrosion Science and Technology
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• 제18권5호
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• pp.168-174
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• 2019

The sol-gel methodology has been applied successfully in the synthesis of a novel hybrid coating based on dimethoxymethyl-n-octadecylsilane precursor. The newly synthesized parent coating was functionalized further with two commercially-available corrosion-inhibitive pigments Moly-$white^{(R)}$ 101-ED and Hfucophos $Zapp^{(R)}$, applied to mild steel panels, and immersed continuously in 3.5% NaCl electrolytic solution for 288 h. The corrosion protection performance of the prepared functional coatings was evaluated using electrochemical impedance spectroscopy (EIS) and DC polarization techniques. An enhancement in the barrier properties has been revealed from the electrochemical characterization data of the hybrid films, in comparison with untreated mild steel substrates following long-term immersion in 3.5% NaCl. The corrosion resistance properties of the newly developed coatings over mild steel substrates found to be largely dependent on the type of the loaded inhibitive pigment in which the Moly-white inhibitor has a positive impact on the corrosion protection performance of the parent coating, while an opposite behavior was observed upon mixing the base polymeric matrix with the commercially-available Zapp corrosion inhibitor.

• 한국광학회지
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• 제1권1호
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• pp.73-86
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• 1990

The technique of Spectroscopic Ellipsometry (SE) has been examined with emphasis on its inherent sensitivity to the existence of thin films or surface equivalents. A brief review of related theories like the Fresnel reflection coefficients, the effect of a multilayer upon reflectivities, together with the validity of the effective medium theory and the modelling procedure, is followed by a short description of the experimental setup of a rotating polarizer type SE as well as the necessful expressions which lead to tan and cos. Out of its numerous, successful applications, a few are exampled to convince a reader that SE can be applied to a variety of research fields related to surface, interface and thin films. Specifically, those are adsorption and/or desorption on metals or semiconductors, oxidation process, formation of passivation layers on an electrode, thickness determination, interface between semiconductor and its oxide, semiconductor heterojunctions, surface microroughness, void distribution of dielectric, optical thin films, depth profile of multilayered samples, in-situ or in-vitro characterization of a solid surface immersed in electrolyte during electrochemical, chemical, or biological treatments, and so on. It is expected that the potential capability of SE will be widely utilized in a very near future, taking advantage of its sensitivity to thin films or surface equivalents, and its nondestructive, nonperturbing characteristics.

• 셀메드
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• 제12권1호
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• pp.5.1-5.8
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• 2022

Ābzan(sitz bath or hydration therapy) is one of the important and widely practised methods of regimenal therapy used for local evacuation or diversion of morbid humours described for various diseases in Unani system of medicine. Itis a type of bath in which hips and buttocks are immersed in water, either plain or medicated for therapeutic effects. Thus, it serves as an important and effective external mode of treatment. It has been successfully practised by Greeko-Arab physicians in the management of almost all types of gynaecological disorders like genital prolapse, leucorrhoea, pruritus vulvae, menstrual disorders, infertility, pelvic inflammatory diseases etc, but its efficacy has been proved in very few gynaecological diseases only. Hence, there is a need for systemic review to investigate the effectiveness of sitz bath in gynaecological disorders to generate scientific based evidence for the clinician as well as for common public. Based on the available literature, this review article suggests that the sitz bath has a scientific evidence-based effect in treating gynaecological diseases.

• 농업과학연구
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• 제15권1호
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• pp.82-94
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• 1988

이 논문(論文)은 기포(起泡)모르터의 제특성(諸特性)에 관(關)한 기초자료(基礎資料)를 제공(提供)하고져 수행(遂行)되었는 바, 이 연구(硏究)를 통(通)하여 얻어진 결과(結果)를 요약(要約)하면 다음과 같다. 1. 각(各) 기포(氣泡)모르터에서 물-시멘트비는 당배합비(富配合比)일수록, 기포제(起泡劑) 및 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 감소(減少)하였으며, 보통(普通)시멘트 모르터에 비(比)하여 혼합기포주입형(混合氣泡注入型)은 1.6~53.1%, 사전기포주입형(事前氣泡注入型)은 4.4~24.1%의 물-시멘트비(比)가 감소(減少)되었다. 2. 각(各) 기포(氣泡)모르터의 밀도(密度)는 빈배합(貧配合)일수록, 기포제(起泡劑) 및 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 작게 나타났으며, 밀도(密度)의 감소율(減少率)은 당배합(富配合)일수록, 기포제(起泡劑) 및 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 크게 나타났다. 3. 기포(起泡)모르터는 보통(普通)시멘트 모르터에 비(比)하여 혼합기포주입형(混合氣泡注入型)은 38.8~55.9%, 사전기포주입형(事前氣泡注入型)은 9.7~23.6%의 자중감소(自重減少)를 보였다. 4. 각(各) 기포(起泡)모르터의 급수율(吸水率)은 빈배합(貧配合)일수록, 기포제(起泡劑) 및 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 높게 나타났으며, 흡수율(吸水率)의 증가율(增加率)은 당배합(富配合)일수록, 기포제(起泡劑) 및 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 크게 나타났다. 5. 72시간(時間) 수침(水浸)에서 각(各) 기포(氣泡)모르터의 흡수율(吸水率)은 보통(普遇)시멘트 모르터에 비(比)하여 혼합기포주입형(混合氣泡注入型)은 3.41~5.85배(倍)로 나타났으며, 사전기포주입형(事前氣泡注入型)은 1.05~1.55배(倍)로 나타났으며, 흡수율(吸水率)의 변화율(變化率)은 모두 수침초기(水浸初期)에 높게 나타나는 경향(傾向)을 보였다. 6. 각(各) 기포(氣泡)모르터의 각(各) 강도(强度)는 빈배합(貧配合)일수록, 기포제(起泡劑) 및 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 작게 나타났으며, 각(各) 강도(强度)의 감소율(減少率)은 빈배합(貧配合)일수록, 기포제(起泡劑)나 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 크게 나타났다. 7. 기포(氣泡)모르터는 보통(普通)시멘트 모르터에 비(比)하여 재령(材齡) 28일(日)에서 혼합기포주입형(混合氣泡注入型)은 77.0~92.8%, 사전기포주입형(事前氣泡注入型)은 36.7~74.4%의 강도감소(强度減少)를 보였고, 각(各) 기포(氣泡)모르터의 각(各) 강도간(强度間)의 상관관계(相關關係)는 직선형(直線形)으로 나타났으며 고도(高度)의 유의성(有意性)이 인정(認定)되었다. 8. 각(各) 기포(氣泡)모르터의 공기량(空氣量)은 빈배합(貧配合)일수록, 기포제(起泡劑)나 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 크게 나타났으며, 공기량(空氣量)이 증가율(增加率)은 당배합(富配合)일수록, 기포제(起泡劑)나 기포(氣泡)의 첨가량(添加量)이 증가(增加)할수록 높게 나타났다. 9. 기포(氣泡)모르터의 공기량(空氣量)은 보통(普通)시멘트 모르터에 비(比)하여 혼합기포주입형(混合氣泡注入型)은 26.0~63.8배(倍), 사전기포주입형(事前氣泡注入型)은 5.8~17.7배(倍)를 보였다. 10. 각(各) 기포(氣泡)모르터에서 밀도(密度)와 흡수율(吸水率), 압축강도(壓縮强度) 및 공기량(空氣量)과의 상관관계(相關關係)는 매우 높은 유의성(有意性)을 보였고, 배합비(配合比)와 기포제(起泡劑) 및 기포(氣泡)의 첨가량(添加量)에 따라 밀도(密度), 흡수율(吸水率), 제강도(諸强度) 및 공기량(空氣量)을 추정(推定)할 수 있는 다중회귀방정식(多重回歸方程式)을 유도(誘導)하였으며 각(各) 방정식(方程式)은 고도(高度)의 유의성(有意性)이 인정(認定)되었다.