• 대한치과기공학회지
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• 제33권3호
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• pp.193-202
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• 2011

Purpose: The aim of this study was to evaluate the effect of pre-treatment of core and hydrothermal treatment on the bond strength and flexural strength of ceramic veneered zirconia. Methods: 3Y-TZP specimens(KaVo Zr, $25mm{\times}3mm{\times}1mm$)were prepared by five pre-treatment methods and divided into seven groups including control two groups, subsequently the specimens veneered with the E-MAX ceram according to manufacturer's information(total specimen thickness 1.5mm). Two groups from ceramic-zirconia specimens(n=105, n=15 per group)were assigned into two experimental fatigue conditions, namely storage in an autoclave at $134^{\circ}C$ for 5h, thermo-cycling(3,000cycles, between 5 and $55^{\circ}C$, dwell time 45s, transfer time 2s). A flexural strength test was performed in a universal testing machine(crosshead speed: 0.5mm/min). Data were statistically analyzed using one-way ANOVA and Tukey's test(${\alpha}$=0.05). Results: The ceramic-zirconia bond strength value for liner application group(LLW, $27.3{\pm}3.8$) were significantly lower than those of the pre-treatment groups($30.72{\pm}5.3$). The ceramic-zirconia bond strength and zirconia flexural strength was not affected by thermo-cycling(p>0.05), whereas it was affected by storage in an autoclave at $134^{\circ}C$ for 5h(p<0.05). Conclusion: The results indicated that the ceramic-zirconia bond strength and zirconia flexural strength was affected by low temperature degradation.

• 대한화학회지
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• 제19권3호
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• pp.156-162
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• 1975

메탄올 속에서 여러가지 치환기를 가진 아닐린과 염화메탄술포닐의 반응을 속도론적으로 연구한 결과 $S_N2 반응메카니즘으로 진행됨을 알았다. 아닐린의 치환기 효과는 Bronsted plot와 Hammett plot로 검토한 결과 직선관계를 얻었다. ${\beta}$값(${\beta}$=0.84)과 ${\rho}$값(${\rho}$=-2.46)으로 보아 전이상태에서 bond formation이 보다 진행된 상태임을 짐작 할수 있었다. 오르트 메틸아닐린의 반응속도는 아닐린의 오르토위치의 입체효과 때문에 아닐린의 메타, 파라치환체를 바탕으로 얻어진 Bronstedplot에서 벗어남을 보여주었다. 파라치환체에 있어서는 치환기의 electron donating ability가 증가함을 따라 ${\Delta}H^{\neq}$의 값은 감소하고 ${\Delta}S^{\neq}$의 값은 음의 값이 커지고 있음을 보여주었다.

• 한국항해학회지
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• 제5권2호
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• pp.49-58
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• 1981

One of the main purposes of the marine gyrocompass follow-up system is to preserve the sensitive part from the wandering error due to the frictional or torsional torque around the vertical axis. This error can be diminished through the rapid follow-up action, which minimizes the relative azimuthal angular displacement between the sensitive and follow-up parts and shortens the duration of the same displacement. But an excessive rapidity of the follow-up action would result in a sustained oscillation to the system. Therefore, to design a new type of the follow-up system, the theoretical annlysis of the problems concerned should be studied systematically by introducing the control theory. This paper suggest a concrete procedure for the optimal adjustment of the gyrocompass follow-up system, utilizing the mathematic model and the stability informations formerly investiaged by the author. For theoptimal determination of the adjustable paramfter K, the performance index(P.I.), ITSE(Intergral of the Time multiplied by the Squared Error) is proposed, namely, P.I. = $\int_{0}^{\infty} t \cdot e^{2}(t)dt$ where t is time and e(t) means control error. Then, the optimal parameter minimizing the performance index is calculated by means of Parseval's theorem and numerical computation, and the validity of the obtained optimal value of the parameter Ka is examined and confirmed through the simulations and experiments. By using, the proposed method, the optimal adjustment can be performed deterministically. But, this can not be expected in the conventional frequency domain analysis. While the Mps of the original system vary to the extent of from 0.98 to 46.27, Mp of the optimal system is evaluated as 1.1 which satisfies the generally accepted frequency domain specification.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.185-191
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• 2005

An experiment was conducted to study the effect of feeding ammoniated wheat straw treated with HCl on blood biochemical profiles in growing male buffalo (Bubalus bubalis) calves. Twenty-four growing male buffalo calves (one year of age, 88.54${\pm}$3.81 kg average body weight) were divided into three groups in a completely randomized design on the basis of their body weight. Animals in all the three groups were fed on concentrate mixture. In addition, they were offered wheat straw, ammoniated wheat straw (4% urea at 50% moisture level) and HCI treated ammoniated wheat straw (4% urea at 50% moisture level and HCl added to trap 30% of the NH3 evolved) in groups I, II and III, respectively for a period of 180 days, as per Kearl (1982) for body weight gain of 500 g/d. In all diets, concentrate:roughage ratio was fixed at 50:50 and were made isonitrogenous by adjusting CP levels of conc. mixtures. Blood was collected from jugular vein of each buffalo calf at the beginning and subsequently at two months interval of experimental feeding. Due to urea-ammoniation, the CP content of wheat straw increased from 2.90 to 6.96% and addition of HCl along with urea further increased the CP content to 10.09%. In all the three groups, the mean values of plasma glucose (mg %) and serum globulin (g %), showed a decreasing trend, while the mean value of serum TP (g %), serum A:G ratio, serum urea (mg %), serum creatinine (mg %), serum ALP (KA units), SGOT (units/ml.), SGPT (units/ml), serum T$_3$ and T$_4$ (ng/ml) showed an increasing trend with the advancement of feeding period. The cumulative period mean values of serum TP (6.15 to 6.20 g %), serum albumin (3.07 to 3.18, g %), serum globulin (2.98 to 3.09, g %), serum A:G ratio (1.03 to 1.10), serum ALP (23.15 to 23.63, KA units), serum T$_3$ (1.20 to 1.23 ng/ml) and serum T$_4$ (21.33 to 21.88 ng/ml) were comparable among the groups. The cumulative period mean plasma glucose (mg %) in group III (57.28) was similar to groups I (55.31) and II (59.41), however, the cumulative period mean plasma glucose in group II was significantly (p<0.01) higher than group I. The cumulative period mean serum urea (mg %) in group III (47.34) was significantly (p<0.001) higher than group I (38.38) and II (42.24), which were statistically alike. However, the cumulative period mean serum creatinine values (mg %) in groups II (1.43) and III (1.52) were similar and were significantly (p<0.01) higher than group I (1.24). The cumulative period mean SGOT (units/ml) in groups I, II and III was 91.71, 96.04 and 96.64, respectively. Similarly the cumulative period mean SGPT (units/ml) was 19.00, 19.93 and 20.01 in groups I, II and III, respectively. The cumulative period mean values of SGOT (p<0.05) and SGPT (p<0.001) in groups II and III were similar and were significantly higher than group I. The cumulative period mean serum T$_3$ and T$_4$ values in groups I (1.21 and 21.81), II (1.23 and 21.42) and III (1.20 and 21.33) were comparable. From the present study it may be concluded that feeding of AWS treated with and without HCI to growing male buffalo calves for 180 days had no significant adverse effect on blood biochemical profile.

• 한국수산과학회지
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• 제56권2호
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• pp.204-211
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• 2023

This study investigated the physicochemical properties and palatability-enhancing effects of the alcohol precipitate, in the enzymatic extracts of Sargassum confusum C. Agardh (SC), obsained using the crude enzyme of Shewanella oneidensis PKA 1008. We analyzed the oligosaccharides recovered from the alcohol precipitate using a thin-layer chromatography for SC-degrading extracts, pH, color, reducing sugar, and viscosity. Thin-layer chromatography showed that after treating with the crude enzyme for 60 h, the polysaccharides were degraded into tetramers, dimers, and trimers and pH increased in the alcohol precipitate (EtOH Sedi). In terms of color, the redness and yellowness of alcohol precipitate/supernatant (EtOH Sedi+Super) and the brightness of EtOH Sedi were the highest among enzyme treated for 0 h and 60 h, EtOH Sedi, and EtOH Sedi+Super. In the reducing sugar analysis, EtOH Sedi showed the lowest value of 13.63 ㎍/mL, and the lowest viscosity of 1.13. In terms of the sensory evaluation, EtOH Sedi+Super showed the highest value with respect to the overall preference. These results suggest that the crude enzyme of S. oneidensis PKA 1008 is effective at degrading polysaccharides, and its recovery increases the palatability of the alcohol precipitate.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1199-1203
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• 2010

Second-order rate constants ($k_N$) have been measured spectrophotometrically for Michael-type reactions of 1-(X-substituted phenyl)-2-propyn-1-ones (2a-f) with a series of alicyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The $k_N$ value increases as the incoming amine becomes more basic and the substituent X changes form an electron-donating group (EDG) to an electron-withdrawing group (EWG). The Br${\o}$nsted-type plots are linear with ${\beta}_{nuc}$ = 0.48 - 0.51. The Hammett plots for the reactions of 2a-f exhibit poor correlations but the corresponding Yukawa-Tsuno plots result in much better linear correlations with ${\rho}$ = 1.57 and r = 0.46 for the reactions with piperidine while ${\rho}$ = 1.72 and r = 0.39 for those with morpholine. The amines employed in this study are less reactive in MeCN than in water for reactions with substrates possessing an EDG, although they are ca. 8 pKa units more basic in the aprotic solvent. This indicates that the transition state (TS) is significantly more destabilized than the ground state (GS) in the aprotic solvent. It has been concluded that the reactions proceed through a stepwise mechanism with a partially charged TS, since such TS would be destabilized in the aprotic solvent due to the electronic repulsion between the negative-dipole end of MeCN and the negative charge of the TS. The fact that primary deuterium kinetic effect is absent supports a stepwise mechanism in which proton transfer occurs after the rate-determining step.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1153-1157
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• 2011

A kinetic study is reported for aminolysis of S-4-nitrophenyl X-substituted thiobenzoates 3a-g in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. Thiol esters 3a-g are 7.8-47.6 fold more reactive than the corresponding oxygen esters (i.e., 4-nitrophenyl X-substituted benzoates 1a-g). Such reactivity order appears to be in accordance with the expectation that 4-nitrothiophenoxide in 3a-g is a better nucleofuge than 4-nitrophenoxide in 1a-g since the former is 2.64 pKa units less basic than the latter. Hammett plot for the reactions of 3a-g exhibit poor correlation coefficients ($R^2$ = 0.977-0.986) with negative deviation by substrates possessing an electrondonating group (EDG), while the Yukawa-Tsuno plots result in excellent linear correlation ($R^2$ = 0.995-0.997) with ${\rho}$ = 0.93-1.23 and r = 0.57-0.67, indicating that the negative deviation shown by substrates possessing an EDG is caused by ground-state stabilization through resonance interactions but not due to a change in ratedetermining step upon changing the nonleaving-group substituent X. The ${\rho}$ value increases as the incoming amine becomes more basic and more reactive, indicating that the RSP is not operative in the current reactions.

• Asian-Australasian Journal of Animal Sciences
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• 제28권11호
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• pp.1551-1557
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• 2015

The missing heritability has been a major problem in the analysis of best linear unbiased prediction (BLUP). We introduced the traditional genome-wide association study (GWAS) into the BLUP to improve the heritability estimation. We analyzed eight pork quality traits of the Berkshire breeds using GWAS and BLUP. GWAS detects the putative quantitative trait loci regions given traits. The single nucleotide polymorphisms (SNPs) were obtained using GWAS results with p value <0.01. BLUP analyzed with significant SNPs was much more accurate than that with total genotyped SNPs in terms of narrow-sense heritability. It implies that genomic estimated breeding values (GEBVs) of pork quality traits can be calculated by BLUP via GWAS. The GWAS model was the linear regression using PLINK and BLUP model was the G-BLUP and SNP-GBLUP. The SNP-GBLUP uses SNP-SNP relationship matrix. The BLUP analysis using preprocessing of GWAS can be one of the possible alternatives of solving the missing heritability problem and it can provide alternative BLUP method which can find more accurate GEBVs.

• 한국약용작물학회지
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• 제23권5호
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• pp.406-413
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• 2015

Background : This study was carried out to investigate the changes to fatty acid, mineral, and ginsenosides contents in ginseng seed when they were stratified for different length of time and to determine whether variety had any effects on the changes. The aim was to improve the ginseng seed stratification process. Methods and Results : The ginseng varieties used were Geumpoong, Chunpoong, Yunpoong, and K-1. Stratifying periods treated on ginseng seed were 0, 20, 40, 60, 80, and 100 days. The main fatty acids of ginseng seed were oleic acid (C18 : 1, n9c) with a content of 78.40 - 79.20% followed by linoleic acid (C18 : 2, n6c). The main mineral in the seeds was potassium (K), at 1208.2 -1337.6 mg/100 g. The main ginsenosides in ginseng seed were ginsenoside Re and Rb1. Increasing the length of the stratification periods led to increases in oleic acid content (60 - 80 days), however after this the content declined. In contrast, linoleic acid content fell as the stratification period increased. K, P, Mg, Ca and Na content rose as the stratification period increased. The ginsenoside Re content of Chunpoong and K-1 cultivar seeds also rose as the stratification period increased which meant that total ginsenoside content increased. However, ginsenoside Re content rose in Geumpoong and Yunpoong seeds, but total ginsenoside content decreased as the stratification period increased. Conclusions : Some beneficial compound in ginseng seed rose as the stratification period increased. Therefore, ginseng seed stratification could improve the food value of ginseng.

• Archives of Plastic Surgery
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• 제47권1호
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• pp.9-14
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• 2020

Background Eyelids vary in morphology and structure depending on age, sex, and race. Usually, one-dimensional measurements are used to evaluate blepharoplasty outcomes. However, in recent years, three- or four- directional enlargements of the eyelid have been used for blepharoplasty in Asian patients, and the outcomes of techniques such as lateral canthoplasty or canthotomy and medial epicanthoplasty with increased scleral area cannot be analyzed using marginal reflex distance 1 or the area of corneal exposure. Therefore, we describe the use of a measurement method based on the eyeball exposure area (EEA). Methods To obtain normal EEA values by age and sex, 320 individuals were recruited. The participants were divided into eight age groups (n=40 in each group: female subjects, n=20; male subjects, n=20): 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-89 years. The EEA value was obtained by dividing the exposed area by the total eyeball area. The normal EEA values and differences in EEA according to age and sex were calculated. Results The mean EEA values for male and female subjects were 66.86% ±9.20% and 71.48%±10.48%, respectively. In each age group, the EEA values of females were higher than those of males. EEA decreased significantly with age in both male and female subjects (P<0.05). Conclusions We determined normal EEA values according to age and sex. EEA can be used as an indicator of the outcome of blepharoplasty.