• Restorative Dentistry and Endodontics
• /
• 제24권3호
• /
• pp.482-489
• /
• 1999

The purpose of this study was to compare sealing ability between lateral condensation and continuous wave of condensation in depend of root canal curvature. In this study, we divided fifty-six human molar teeth into two group in depend of Schneider method, and then subdivided them into four experimental group (each group is composed of twelve teeth) by canal curvature and obturation method, and eight teeth were served as positive and negative controls. Specimens were prepared by Quantac 2000 series file and obturated by lateral condensation or System B. Specimens were immersed in india ink for 7 days, decalcified by 10% nitric acid, dehydrated by 75, 95 and 100% alcohol in order, cleared by methyl salicylate and then measured of dye penetration with stereomicroscope(${\times}6.5$ magnification) and Image Pro plus. The data were analyzed stastically by one-way ANOVA and Scheffe test. The data were as follows: 1. The mean leakage was $0.725{\pm}1.167$ for group A, $0.813{\pm}0.921$ for group B, $0.809{\pm}0.997$ for group C, $1.111{\pm}1.147$ for group D, but no significant difference among them(p>0.05). 2. Lateral condensation had better sealing ability than continuous wave of condensation, but no significant difference among them(p>0.05). 3. There was no significant difference between root canal curvature degree and microleakage(p>0.05).

• Restorative Dentistry and Endodontics
• /
• 제9권1호
• /
• pp.59-68
• /
• 1983

The purpose of this study was to examine the influence of canal irrigants and the method of canal filling on the quality of canal obturation. Sixty extracted human teeth with single root were selected and divided into three different groups; In group I (control); 5 cc normal saline irrigated after each instrumentation In group II; 2.5 cc-3% NaOCl in combination with 2.5 cc-3% $H_2O_2$ In group III; RC-Prep in combination with 5 cc-3% NaOCl All specimens were cleaned, shaped(#50 file size), irrigated and obturated by lateral condensation and automated thermatic condensation filling method of gutta-percha and AH-26. After all the specimens were immersed in 2% methylene blue dye solution in $37^{\circ}C$ for 7 days and the degree of dye penetration into the canals observed by magnifying glass(${\times}$20) and reflected light microscope The results were as follows: 1. All the the teeth showed some degree of the dye penetration. 2. There were no significant difference among three groups in the degree of the dye penetration in each canal filling method. 3. There were no significant difference of the dye penetration between each canal filling method in group I. 4. There were no statistically significant difference of the dye penetration between each canal filling method in group II and group III, but lateral condensation group was showed slightly more than automated thermatic condensation group.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.104-109
• /
• 2001

The time to measure the size distribution using Condensation Nuclei Counter(CNC) and Differential Mobility Analyzer(DMA) can be shortened by classifying particles ramping the DMA voltage exponentially and continuously. In measurement, particles sampled at different time are mixed together going through sampling tube and CNC. Because the size distribution is inversed by using detector responses to sampling time intervals in this accelerated method, the mixing effects give inversion errors to the size distribution. The mixing effects can be considered by appling the transfer function with mixing effects to the data inversion. The inversion considering this effects gives birth to the size distribution shifted to the opposite direction of the size scanning.

• 설비공학논문집
• /
• 제17권4호
• /
• pp.303-311
• /
• 2005

The problem of conjugate laminar film condensation of the pure saturated vapor in forced flow over a flat plate has been investigated as boundary layer solutions. A simple and efficient numerical method is proposed for its solution. The interfacial temperature is obtained as a root of 3rd order polynomial for laminar film condensation, and it is presented as a function of the conjugate parameter. The momentum and energy balance equations are reduced to a nonlinear system of ordinary differential equations with four parameters: the Prandtl number, Pr, Jacob number, $Ja^{\ast}$, defined by an overall temperature difference, a property ratio R and the conjugate parameter ${\zeta}$. The approximate solutions thus obtained reveal the effects of the conjugate parameter.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.631-636
• /
• 2007

Eigenvalue reduction schemes approximate the lower eigenmodes that represent the global behavior of the structures. In the, we proposed a two-level condensation scheme(TLCS) for the construction of a reduced system. In first step, the of candidate elements by energy estimation, Rayleigh quotient, through Ritz vector calculation, and next, the primary degrees of freedom is selected by sequential elimination from the degrees of freedom connected the candidate elements in the first step. In the present study, we propose TLCS combined with iterative improved reduced system(IIRS) to increase accuracy of higher modes intermediate range. Also, it possible to control the accuracy of the eigenvalues and eigenmodes of the reduced system. Numerical examples demonstrate performance of proposed method.

• Mass Spectrometry Letters
• /
• 제9권1호
• /
• pp.37-40
• /
• 2018

Farinomalein is a maleimide-bearing compound well known for its anti-fungal activity. In the present study, synthesis of farinomalein is achieved via Stobbe condensation followed by Haval-Argade contrathermodynamic rearrangement. Kinetically driven Stobbe condensation followed by condensation with beta-alanine reveals formation of two isomers of farinomalein. This article describes application of LC-MS/MS in structure elucidation of farinomalein 1 and its isomers 2 and 3 encountered in its synthesis. The proposed distinct fragmentation pathway is supported by rational organic reaction mechanism. These fragmentation pathways are significant for analytical method development of farinomalein in near future. The structures of farinomalein 1 and its isomers 2 and 3 have been assigned undisputedly.

• 한국환경과학회지
• /
• 제31권1호
• /
• pp.43-50
• /
• 2022

In this paper, lysimeter was installed to analyze the moisture fluctuations on the surface of a forest. The weight of the soil was measured, and the moisture fluctuations were calculated through the difference in weight over time. The amount of dew condensation on the surface of the ground was about 2-7 mm. January experienced the most dew condensation (7.2 mm). It was found that about 43 mm of dew condensation was generated over one year. To analyze the characteristics of evapotranspiration in the forest, the evapotranspiration on the surface was measured by the lysimeter method and the evapotranspiration on the upper part of the canopy was measured by the eddy covariance method. These results were compared and analyzed. Until mid-October, the evapotranspiration of the forest was active, and the amount of evapotranspiration on the top of the canopy was higher than the amount on the surface. Thereafter, the amount of evapotranspiration on the top of the canopy decreased due to the lowering of temperature and net-radiation. The amount of evapotranspiration on the surface and above the canopy showed the same tendency.

• Bulletin of the Korean Chemical Society
• /
• 제31권5호
• /
• pp.1301-1304
• /
• 2010

The Indium modified mesoporous zeolite AlMCM-41 were synthesized by hydrothermal method and characterized by powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) techniques. The Knoevenagel condensation of aldehyde with malononitrile or ethyl cyanoacetate was carried out at reflux condition in ethanol by using heterogeneous In/AlMCM-41 catalyst. This method is fast, efficient, easy work-up and eco-friendly to afford the corresponding Knoevenagel adducts. The catalyst was recovered and reused for several cycles with consistent activity.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.579-584
• /
• 2001

Agglomerated and nonagglomerated SiO2 particles are synthesized in furnace by the electrohydrodynamic spraying method and the vapor feeding method for the test particle generator this study. These polydispersed particles are classified with DMA to extract equal mobility particles. Then these particles are introduced into CNC (Condensation Nuclei Counter) to see the pulse height using Multi-channel Analyzer. The response characteristics of these two kinds of particles in CNCs (TSI CNC 3022 and 3025A) have been studied as a function of particle size using mono disperse particles classified by DMA. The results show that the higher drag resistance particles, so called agglomerated particles have generated a lower CNC pulse height than the spherical particles for these two different CNCs, which means the nonagglomerated particles may start to grow larger than the agglomerated particles.

• 한국전산유체공학회지
• /
• 제17권4호
• /
• pp.9-15
• /
• 2012

Thermal model reduction algorithms and techniques are introduced to condense a huge satellite panel thermal model into the simplified model on the purpose of calculating the thermal responses of a satellite on orbit. Guyan condensation algorithm with the substitution matrix manipulation is developed and the mathematical procedure is depicted step by step. A block-form LU decomposition method is also invited to compare the developed algorithm. The constructed reduced thermal model induced from the detailed model based on a real satellite panel is satisfying the correlation criterion of ${\pm}2^{\circ}C$ for the validity accuracy. Guyan condensation algorithm is superior to the block-form LU decomposition method on computation time.