• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.113-122
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• 2000

The reinforced composte resin as the esthetic operative material continuously has been studied because the porcelain fused metal prosthesis is widely used for its excellent esthetics, rigidity and marginal integrity, but it has low fracture resistance against the tensile strength and stress, attrition of the opposite teeth. The reinforced composite resin is well adapt with the dental alloy but it is low the shear bond strength with the dental alloy vs the porcelain fused metal prosthesis, and then has been studied continuously. The purpose of the study was to examine how metal was the higher shear bond strength among the dental alloy was used to the reinforced composite resin and to find the effect that the particle size of sandblasting influenced the shear bond strength. We built up the reinforced composite resin with 4 mm in diameter, 3 mm in height on circular alloy with 5 mm in diameter, 2 mm in height. Type II gold, type IV gold, and Ag-Pd alloy was used as alloys and $50{\mu}m$, $110{\mu}m$, $250{\mu}m$ of the particle size was sandblasted at each alloy in bonding between alloy and resin. We made 90 secimens of 10 per each group and we measured the shear bond strength using the Instron($M100EC^{(R)}$, Mecmesin Co., England). The obtained results were as follows : 1. In comparison among each alloys, Ag-Pd alloy had the highest shear bond strength and the shear bond strength was decreased significantly in the sequence of the type II gold and type IV gold(P<0.001). 2. In comparison according to the size of sandblasting particle, (1) In Ag-Pd alloy, shear bond strength was decreased in the sequence of $110{\mu}m$, $250{\mu}m$, $50{\mu}m$ and there were significant difference in all the group. (P<0.05) (2) In type II gold, it was decreased in the sequence of $250{\mu}m$, $50{\mu}m$, $110{\mu}m$ and there were significant difference. (P<0.05) (3) In type IV gold, it was decreased in the sequence of $110{\mu}m$, $50{\mu}m$, $250{\mu}m$. There were significant difference between the group of $110{\mu}m$ and $50{\mu}m$, the group of $110{\mu}m$ and 250, but there were no significant difference in the group of $50{\mu}m$ and $250{\mu}m$. 3. The highest shear bond strength according to the size of sandblasting particle was $110{\mu}m$ in Ag-Pd alloy and type IV gold, $250{\mu}m$ in type II gold.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.262-268
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• 2005

Intoxication of murine macrophages (RAW 264.7) with the anthrax lethal toxin (LeTx 100 ng/ml) results in profound alterations in the host cell gene expression. The role of LeTx in mediating these effects is unknown, largely due to the difficulty in identifying and assigning function to individual proteins. In this study, we have used two-dimensional polyacrylamide gel electrophoresis to analyze the protein profile of murine macrophages treated with the LeTx, and have coupled this to protein identification using MALDI-TOF mass spectrometry. Interpretation of the peptide mass fingerprint data has relied primarily on the ProFound database. Among the differentially expressed spots, cleaved mitogen-activated protein kinase kinase (Mek1) and glucose-6-phosphate dehydrogenase were increased in the LeTx treated macrophages. Mek1 acts as a negative element in the signal transduction pathway, and G6PD plays the role for the protection of the cells from the hyper-production of active oxygen. Our results suggest that this proteomic approach is a useful tool to study protein expression in intoxicated macrophages and will contribute to the identification of a putative substrate for LeTx.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.1
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• pp.20-25
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• 1989

This experiment was carried out in order to know the decreasing causes of plant density and its relations with pasture productivity by the times of established pasture. The results were summarized as follows, 1. The yield components of dead plant can be used to estimate the changes of pasture productivity by the times of established pasture. 2 . The number of dead plants(PD) showed a quadraticalrelation with mean dry weight of dead plant $W/pl.)$ by the times of established pasture. 3. Relationship between relative number of tillers per dead plant to mean number of tillers of adjacent plants (RNT) and relative ratio of number of tillers per dead plant to number of tillers of plants in the 1st cutting (RNDT) showed highly positive significant correlation in 1 and 3 years old pasture. 4. Less than 100 of RNT were 79.5 %, 71.4 % and 100 % of dead plants in 1, 3 and 5, and 7 years old pasture, respectively. 5. Not exceeding values of RNDT to MRRNT were 89.7 %, 71.4 % and 100 % of dead plants in 1, 3 and 5, and 7 years old pasture. 6 . The values of 79.5 %, 57.2 % and 100 % of dead plants in 1, 3 and 5, and 7 years old pasture were not exceeding to MRRNT and less than 100 of RNT. 7. From the results described above, it was discussed that the relative number of tillers per dead plant(RNT) should be described not absolute deaeasing causes of plant density in 1 and 3 yars old pasture. But, the total number of dead plants in 5 and 7 years old pasture were absolutely influenced by RNT and MRRNT.

• Journal of The Korean Association For Science Education
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• v.5 no.1
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• pp.63-79
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• 1985

The purpose of our survey study was to investigate the status on perception and actual state toward science educational evaluation and objectives of middle school science teachers in Pusan. The perception and actual state were surveyed by the questionaire which was developed by Jong-Ok Woo et. al. We developed two kinds of questionaire. One is designed to use Likert type scale and is composed of two main category(SE; Science educational evaluation, SO; Science educational objectives) which contains 21 question items, and the other has 16 question items From 313 science teacger's responses of 75 middle schools in pusan, the tendency. of total(SE+SO) and each sub category, and the contrast with their background and actual state were analized by SPSS program of KAIST. Some results of our survey study can be summarized as follows; 1. Total tendency of science educational evaluation(SE) and objectives(SO) of middle school science teachers in pusan shows a positive and right tendency of conception in general(m-85.8/100). 2. Tendency of SE(m-87.8/100) are slightly higher than SO(m-81.7/100). At the level of 5% significance, there are correlated but shows low correlation (r=0.12(4). 3. In each correlation toward total tendency(SE+SO), SE is highly correlated(r-0.8486) but SO is moderately correlated(r=0.6297) at the level of 0.1% significance. 4. Tendencies of 5sub category (PE, PC, PD, PO, PB) shows considerably right tendencies (m=$73.4/100{\sim}92.7/100$), there are moderately correlated foward total tendency(SE+SO) at the level of 0.1% significance (r=$0.49{\sim}0.60$). 5. At the level of 5%significance, total means are no differences which their background(Sex, Final alma mate, Major, Difference of training), but there is differences to teaching career at the level of 5% significance.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.309-316
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• 2006

Three sex pheromone components (cis-8-dodecenyl acetate (Z12Ac), trans-8-dodecenyl acetate (E12Ac), cis-8-dodecenol (Z12OH)) of the Oriental fruit moth, Grapholita molesta, were chemically synthesized. Especially to increase the composition of cis-stereoisomer, a triple bond intermediate was hydrogenated at $-20^{\circ}C$ with catalytic $Pd/BaSO_{4}$. The resulting product consisted of the acetates with a stereoisomer ratio in 92:8 (Z:E). The biological activity of the synthesized pheromone compounds was analyzed both in male responses and orientation disruption. The indoor pheromone effect was determined by male flight behavior showing wing movement in response to lure. Different mixtures of the synthetic pheromone components were prepared by mixing acetate and alcohol components in 100:0, 99:1, and 90:10 (g/g) and tested with a comparison of a standard commercial pheromone lure. The highest pheromone effect was observed in only acetate mixture (100:0) and the effect was reduced with the addition of the alcohol component. This indoor pheromone effect could be observed in field monitoring trial, in which 100:0 mixture showed the highest trap catches. Orientation disruption assay was conducted indoor by using a cage, in which the center had a commercial lure on sticky plate and the four candidates were placed at 6 cm away from the central lure on each of four directions. Test males were released to the arena during overnight (12 h) and then the caught males on the sticky plate were counted. The synthesized pheromone as well as the commercial pheromone showed 100% orientation disruption. However, the orientation disruption effect was reduced with decrease in the number of the surrounding disrupting pheromone baits. These results clearly suggest that the synthesized sex pheromone of G. molesta is biologically active and can be used for field mating disruption.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.266-272
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• 1994

An essential ingredient in precision machining is a positioning system that responds quickly and precisely to very small input signal. In this paper, two different positioning systems were presented fot the precision positioning control. The one is a friction drive system, the other is a ballscrew system. The friction drive system was composed of an air sliding guide and a friction drive. The ballscrew system was made of a ballscrew and a linear guide. Nonlinear behaviors of the given systems tend to make the system inaccurate. The paper looked at the phenomena that has caused the positioning error. These apparently nonlinear phenomena can be attributed mainly to the presence of the nonlinear friction and slip effect plus the dynamic change from the microdynamic to the macrodynamic and form the macrodynamic to the microdynamic. For the control of the positioning system, the control algorithm based on a neural network is suggested. The FEL(Feedback Error Learning) controller can learn the inverse dynamics of a nonlinear system by using the neural network controller, and stabilize the system by a linear controller. In the experiment, PTP control is implemented withen the maximum error of 0.05 .mu.m ~0.1 .mu. m when i .mu.m step reference input is applied and that of maximum 1 .mu. m when 100 .mu.m step reference input is given. Sinusoidal inputs with the amplitude of 1 .mu.m and 100 .mu. m are used for the tracking control of the positioning system. Experimental results of the proposed algorithm are shown to be superior to those of conventional PD controls.

• Analytical Science and Technology
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• v.8 no.4
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• pp.435-442
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• 1995

A matrix modification was studied for the determination of trace bismuth in water samples by graphite furnace atomic absorption spectrophotometry. The type and quantity of modifiers as well as the use of auxiliary modifiers were investigated to realize the efficient modification. Palladium was chosen as a single modifier. By the addition of palladium($5{\mu}g/mL$) to 100 ng/mL bismuth solution, the temperatures could be raised from $500^{\circ}C$ to $1,300^{\circ}C$ for the charring and from $2,000^{\circ}C$ to $2,200^{\circ}C$ for the atomization as well as the sensitivity and reproducibility were improved. The absorbance of bismuth was maximum and not changed in the range of Pd $3-25{\mu}g/mL$. And several materials were examined as an auxiliary modifier. The mixed solution of $1{\mu}g/mL$ palladium and $200{\mu}g/mL$ nickel have raised the temperatures as with $5{\mu}g/mL$ palladium only. The maximum absorbance of bismuth was shown in the nickel concentration range of $100-300{\mu}g/mL$ in $1{\mu}g/mL$ palladium modified system. With such optimum conditions, the trace amount of bismuth in several water samples could be determined by a calibration curve method, and good recoveries were also obtained.

• Journal of the Korean institute of surface engineering
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• v.25 no.4
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• pp.189-206
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• 1992

The effect of activation and electroless nickel plating conditions on contact properties was investi-gated for selective electroless nickel plating of Si wafers in order to obtain an optimum condition of con-tact hole filling. According to RCA prosess, p-type silicon (100) surface was cleaned out and activated. The effects of temperature, DMAB concentration, time, and strirring were investigated for activation of p-type Si(100) surface. The optimal activation condition was 0.2M HF, 1mM PdCl2, 2mM EDTA,$ 70^{\circ}C$, and 90sec under ultrasonic vibration. In electroless nickel plating, the effect of temperature, DMAB concentra-tion, pH, and plating time were studied. The optimal plating condition found was 0.10M NiSO4.H2O, 0.11M Citrate, pH 6.8, $60^{\circ}C$, 30minutes. The contact resistance of films was comparatively low. It took 30minutes to obtain 1$\mu\textrm{m}$ thick film with 8mM DMAB concentration. The film surface roughness was improved with decreasing temperature and decreasing pH of the plating solution. The best quality of the film was obtained at the condition of temperature $60^{\circ}C$ and pH 6.0. The micro-vickers hardness of film was about 800Hv. Plating rate of nickel on the hole pattern was slower than that of nickel on the line pattern.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2377-2379
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• 1999

In order to analyze failure rates of underground transmission power cable systems in Korea, the survey has been performed for the failure cases of cables, joints, and terminations in CV, OF and POF cable systems which occurred from 1983 to 1998. During 16 years, the failure cases due to trips of the systems were 47 among the total 108 cases, These 47 cases could be divided into internal reasons(manufacture/installation, corrosion and degradation) of 16 cases and external reasons (external mechanical damages, lightning, fire. etc.) of 31 cases. For the 154 kV cable systems during 12 years from 1987 to 1998, total failure rate was 0.0057 [case/100C-km/year] and internal reason failure rate was 0.0020 [case/100C-km/Year], which is similar to those of foreign countries. Also, the many cases of internal reason failures occurred in the early stage after the operations due to incorrect installations. This implies that the installation process is very important and some diagnostic tests such as PD measurement are needed besides after laying test.

• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.43-48
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• 2009

Salmonella enterica serovar Gallinarum is the causative agent of fowl typhoid (FT) and Salmonella enterica serovar Pullorum is pullorum disease (PD), a severe systemic disease of chick and it has the same antigenic fomula, the close relation but distinct pathogen. The traditional bacteriologic and serologic methods routinely used but tedious, time consuming. some of biochemical differences are helpful in differentiating the two organisms, however variation in the characteristics of some strains can be observed. During 2006 to 2008, there was isolated 30 strains. The biochemical characteristics of S. Gallinarum was nonmotile, fermentation of dulcitol, maltose but positive arginine (6.6%), lysine (83.3%) and arabinose (20.0%). The antimicrobial susceptibility test showed 100% sensitive to amikacin, ampicillin, amoxicillin/clavulanic acid and florfenicol, but resistant to penicillin (100%) and erythromycin (60.0%). This PCR method can be applied in the diagnosis between S. Gallinarum and S. Pullorum.