• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.708-722
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• 2010

This study was carried out to classify vegetation structure of the Hyangjeokbong in the Deogyusan National Park using the gradient analysis and phytosociological method. The vegetation was classified into Quercus mongolica community(Rhododendron schlippenbachii subcommunity, typical subcommunity), Q. serrata community, Q. variabillis community, Pinus densiflora community, Cornus controversa community, Fraxinus mandshurica community and Taxus cuspidata community. Ecological characteristics such as species composition, layer structure, vegetation ratio, and the distribution of individual trees by DBH(diameter at breast height) were significantly different among communities. The order of important value of the forest community with DBH 2cm above plants was Q. mongolica(81.2), F. mandshurica, Q. serrata, P. densiflora, Acer pseudosieboldianum, Q. variabillis, Rhododendron schlippenbachii, C. controversa, T. cuspidata. Distribution of DBH of Q. mongolica and Q. serrata had suggesting a continuous domination of these species over the other species for the time being. In contrast, F. mandshurica appeared limited to the valley of the sheet and a higher frequency of young individuals, suggesting a continuous domination of these species the development of a climax forest terrain. P. densiflora and T. cuspidata had suggesting a continuous domination of these species over the other species for the time being in maintain. Q. variabilis and C. controversa had a formality distribution, suggesting a continuous domination of these species over the other species for the time being. This study examined the correlation between each community and the environment according to DCCA ordination. The Q. mongolica community and T. cuspidata community predominated in the highest elevation habitats which had few moisture, Ca and in the low pH. The Q. serrata community mainly occurred in the low elevation habitats which had many moisture. P. densiflora community predominated in the middle elevation and south-facing slope habitats which had few moisture, Ca and in the low pH. F. mandshurica community predominated in the low elevation habitats which had many moisture, Ca and pH.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.82-89
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• 2010

An experiment was conducted to determine the influence of dietary inorganic (copper sulfate) and organic (copper proteinate) forms of copper and energy level on performance and nutrient utilization of broiler chickens. Two hundred day-old commercial Vencobb broiler chicks were purchased and randomly distributed to 20 cages of 10 birds each. These replicates were randomly assigned to one of five treatments in a (($2{\times}2$)+1) factorial arrangement. These two factors were sources of Cu ($CuSO_{4}$ vs. Cuproteinate) and dose of Cu supplements (200 mg and 400 mg/kg dietary dry matter) and the control (no supplemental Cu). After the starter period (up to 3 weeks), from d 22 onwards another factor i.e. energy at two levels (2,900 vs. 2,920 kcal/kg diet) was introduced with the previous factorial arrangements by subdividing each replicate into two equal parts, for two energy levels, without disturbing the dose and source of Cu supplement. Cu-salt supplementation linearly increased (p<0.01) live weight (LW), live weight gain (LWG) and feed conversion ratio (FCR) at 3 weeks, whereas cumulative feed intake (CFI) was unaffected (p>0.05). LWG and FCR were higher (p<0.01) in Cu-proteinate supplemented birds compared to $CuSO_{4}$ supplementation. A linear dose response (p<0.01) of Cu was found for the performance of broiler chickens. Birds having a higher energy level in the finisher stage increased (p<0.01) LWG and FCR. Cumulative feed intake was similar (p>0.05) across the groups up to the 5th week. Cu-proteinate increased performance of broiler chickens compared to $CuSO_{4}$. Dose of supplemental Cu-salt irrespective of source showed a linear response (p<0.01) for performance. Supplementation of Cu-proteinate increased metabolizability of DM (p<0.01), NFE (p<0.05), total carbohydrate (p<0.01) and OM (p<0.01) at the starter period. Increased dose of Cu-salt linearly increased (p<0.01) metabolizability of DM, CP, CF, NFE and OM. Higher energy level in the diet improved DM (p<0.05), EE (p<0.01), NFE (p = 0.01), total carbohydrate (p<0.01) and OM (p<0.01) metabolizability. Cu-proteinate supplementation showed better nutrient utilization compared to CuSO4. Dose of Cu linearly increased DM, CP, EE, NFE, total carbohydrate and OM metabolizability. CF metabolizability was unaffected (p>0.05) among the treatments. In conclusion, dietary supplementation of Cu-salt more than the requirement may improve performance and nutrient utilization in broiler chickens even with a high energy finisher diet. Cu-proteinate showed better performance and nutrient utilization compared to $CuSO_{4}$.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.156-161
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• 2013

We fabricated transparent conductive electrodes with silver (Ag) nanofibers by electrospinning process. Ag nanofibers have high aspect ratio and fused junctions which result in low sheet resistance. Electrospinning is a fast and efficient process to fabricate continuous one-dimensional (1D) nanofibers. Ag/polymer ink were prepared in polymer matrix solution by a sol-gel method. Then, Ag/polymer nanofibers precursors are heated at $200{\sim}500^{\circ}C$ in air for 2 h to eliminate partially the polymers. The topographical features of the Ag nanofibers were characterized by FE-SEM, and the electrical property was analyzed through I-V measurement system. Finally, optical property was measured using UV/VIS spectroscopy. The transparent conductive electrodes with Ag nanofibers exhibited a sheet resistance (Rs) of $250{\Omega}/sq$ at a transparency (T) of 83%. Transparent conductive films, contain the Ag nanofibers as conductive materials, have good electrical, optical, and mechanical properties. Therefore, it is expected to be useful for the application of flexible display in the future.

• Nuclear Engineering and Technology
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• v.28 no.5
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• pp.458-466
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• 1996

The effects of dopants on the modification of microstructure of UO$_2$ and UO$_2$-4wt%CeO$_2$ sintered pellets have been studied in hydrogen and $CO_2$/CO mixture atmospheres by using $Ta_2O_5$, TiO$_2$ and $Nb_2O_5$ as sintering additives. The dopant were added as oxide powders and homogenized by attrition milling. The mixed powders were pressed, and then sintered in hydrogen at 1$700^{\circ}C$ , or in oxidizing atmosphere using Controlled $CO_2$/CO mixtures at 125$0^{\circ}C$. Both density and microstructure of UO$_2$ are modified by the addition of dopants in reducing atmosphere. The sintered density is increased with $Ta_2O_5$ addition up to 0.33wt% and subsequently decreased with higher content of the additive. The effect on the densification and the gain growth are apparent with the addition of 0.24wt% $Nb_2O_5$. With 0.lwt% titania and 0.6wt% $Ta_2O_5$, the sintered density is decreased, but the grain size is increased. In oxidizing atmosphere, the grain sizes for UO$_2$ doped with the above additives are smaller than that for pure UO$_2$. The grain size of Ta or Nb-doped UO$_2$ is decreased with increasing $CO_2$/CO ratio, but that of pure UO$_2$or T-doped UO$_2$ is increased. A large portion of second phases is observed in UO$_2$ doped with 0.lwt% TiO$_2$ sintered in hydrogen atmosphere, while, in $CO_2$/CO atmospheres, the second phases or dopant agglomerates are not observed. For UO$_2$-4wt%CeO$_2$ mixed oxide, the effect of additives on the gain growth is not so much as that for the pure UO$_2$. This is attributed to the formation of clusters by dopant cations and Ce ions, so that the additives contribute to a lesser exent to the grain growth for the mixed oxide.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.377-383
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• 2006

The purpose of the present study was to examine the pharmacokinetic characteristics of arsenic hexaoxide($As_4O_6$), a novel anticancer compound, after i.v. bolus and oral administration in rats. We developed an ICP-Mass based method to analyze arsenic hexaoxide levels in plasma, bile, urine, feces, and tissue and validated the method. Arsenic hexaoxide rapidly disappeared from the plasma by 10 min($\alpha$ phase) after i.v. administration, which was followed by the late disappearance in the $\beta$ phase. The mean plasma half-lives($t_{1/2}$) of arsenic hexaoxide at the a and $\beta$ phase when administered at a dose of 5 mg/kg were 1.57 and 29.8 min, respectively. The maximum plasma concentration($C_{max}$) was 230 ng/mL, after oral administration of arsenic hexaoxide at a dose of 50 mg/kg. The bioavailability, which was calculated from the dose-adjusted ratio, of the oral administered arsenic hexaoxide was 1.61%. Of the various tissues tested, arsenic hexaoxide was mainly distributed in the spleen, lung, liver and kidney after oral administration. Arsenic hexaoxide levels in the spleen or lung at 24 hr after oral administration were higher than those of maximum plasma concentration($C_{max}$). The cumulative amounts of arsenic hexaoxide found in the urine by 48 hr after the administration of 50 mg/kg were 5-fold higher than those in the bile. However, the cumulative amounts in the feces were 10-fold higher compared with those of urine, suggesting that arsenic hexaoxide is mostly excreted in the feces. In conclusion, our observations indicated that arsenic hexaoxide was poorly absorbed from the gastro-intestinal tract to the blood circulation and transferred to tissues such as the spleen and lung at 24 hr after oral administration. Moreover, the majority of arsenic hexaoxide appears to be excreted in the feces by 48 hr after oral administration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.24-25
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• 2006

SmBCO coated conductors were successfully fabricated using EDDC (Evaporation using Drum in Dual Chambers) deposition system that is a bath type co-evaporation system for fabrication of superconducting tape and divided into two chambers named evaporation chamber and reaction chamber. To obtain long and high quality superconducting coated conductor, it is very important to secure the uniformity of all the deposition parameters m the deposition system such as deposition temperature, oxygen partial pressure, compositional ratios and so on. Therefore, we investigated the distribution of the parameters along the axis of the drum m EDDC on which tapes were wound helically. When the temperature on the middle point of deposition zone was $700^{\circ}C$, that on the edge of deposition zone was $675^{\circ}C$. When the thickness of SmBCO layer on the middle point of deposition zone was 1063 nm, that on the edge of deposition zone was 899 nm. The partial pressure of oxygen was 5 mTorr in the reaction chamber while that was $7{\times}10^{-5}$Torr in the evaporation chamber. The composition ratio of Sm:Ba:Cu, that was measured by EDX, was very uniform along the axis of the drum. Under these deposition conditions, critical current distribution along the drum axis was 175 A/cm, 190A/cm, 217.5 A/cm, 182.5 A/cm, 175 A/cm with the interval of 9 cm between samples. It means that the EDDC system has the potential of fabricating (100m, 200A) class coated conductor.

• Clean Technology
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• v.17 no.2
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• pp.166-174
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• 2011

The xAl-yCe oxide catalysts with different mol ratios of Al/(Al+Ce) were prepared by a co-precipitation method and Pt supported on xAl-yCe oxide catalysts were synthesized by an incipient wetness impregnation method. The catalysts were characterized by X-ray Diffraction (XRD), $N_2$ sorption, and $H_2$/CO-temperature programmed reduction ($H_2$/CO-TPR) to correlate with catalytic activities in co oxidation. Among the catalysts studied here, Pt/1Al-9Ce oxide catalyst showed the highest activity in dry and wet reaction conditions and the catalytic activity showed a typical volcano-shape curve with respect to Al/(Al+Ce) mol ratio. When the presence of 5% water vapor in the feed, the temperature of $T_{50%}$ was shifted ca. $30^{\circ}C$ to lower temperature region than that in dry condition. From CO-TPR, the desorption peak of $CO_2$ on Pt/1Al-9Ce oxide catalyst showed the highest value and well correlated the catalytic performance. It indicates that the Pt/1Al-9Ce oxide catalyst has a large amount of active sites which can be adsorbed by co and easy to supplies the needed oxygen. In addition, the amount of pentacoordinated $Al^{3+}$ sites obtained through $^{27}Al$ NMR analysis is well correlated the catalytic performance.

• Advances in pediatric surgery
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• v.19 no.2
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• pp.81-89
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• 2013

The purposes of this study was to describe the clinical correlation of mass size and gestational age, prognostic factors in sacrococcygeal teratoma (SCT) at a tertiary pediatric surgery, University of Ulsan College of Medicine and Asan Medical Center (AMC), Seoul, Korea. Fifty five patients admitted to the AMC with a SCT between May 1989 and April 2013 were included in this retrospective review. Mean follow up was 861 days. Mean maternal age at delivery was $30{\pm}2.7$ year, mean gestational age (GA) was $36.9{\pm}3.6$ wks, and preterm delivery was 21.8%. Birth body weight was $3182{\pm}644$ g and male vs. female ratio was 1:2.05. We can't find significant difference between Caesarean section and maternal age at delivery (p =0.817). But, caesarean section was favored by gestational age (p = 0.002), larger tumor size (p =0.029) or higher tumor weight fraction rate to birth body weight (p =0.024). Type I was 13, II 21, III 17, and IV 3 according to Altman et al. classification. The tumor component was predominantly cystic(> 50%) in 73.1 %. And the majority histological classification of tumors were mature teratoma (70.3%). The motality rate was 5.5%. Three patients expired because of postpartum bleeding, post-op bleeding related complication such as DIC. SCT recurred in four patients. The interval between first and second operation was $206.2{\pm}111.0$ d (range 53~325 d). In two patients, serum AFP levels were elevated at a regular checkup without any symptom, and subsequent imaging studies revealed SCT. The most common cause of death was bleeding and bleeding related complication. So Caesarean section and active peripartum and perioperative management will be needed for huge solid SCT. In the case of Yolk sac tumor or huge immature teratoma, possibility of recurrence have to be always considered, so follow up by serial AFP and MRI is important for SCT management.

• Advances in pediatric surgery
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• v.12 no.1
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• pp.53-69
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• 2006

This is a survey on congenital posterolateral diaphragmatic hernia, conducted by the Korean Association of Pediatric Surgeons(KAPS). A registration form for each patient during the 5-year-period between 1998 and 2002 and a questionaire were sent to each member. Twenty-ninemembers in 22 institutions returned completed forms. The average number of patients per surgeon was 1.4 cases a year. The male to female ratio was 1.64: 1, and annual incidencewas 1/14,522 live births. In this review, factors influencing survival in congenital posterolateral diaphragmatic hernia were age at admission, birth weight, time of antenatal diagnosis, birth place, Apgar score, onset time of symptoms and signs, preoperative cardiopulmonary resuscitation, associated anomalies of themusculoskeletal system, central nervous system, or chromosomes, preoperative stabilization, levels of preoperative $FiO_2$, pH, and $AaDO_2$, perioperative complications, bilaterality of defect, size of the defect, and presence or absence of hernia sac.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.263-271
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• 2006

This experiment was conducted to evaluate the effects of dietary Hwangto on growth performance and body composition in broiler chicks. A total of 216 one-day old 'Ross' broilers were assigned to 6 treatments in a completely randomized design. The six dietary treaoents were control no Hwangto added and diets containing 0.5, 1.0, 2.0, 4.0 and 8.0% of Hwangto supplementation. The weight gain of broilers tended to reduce with increasing level of Hwangto. However, there were no significant differences in feed intake and feed conversion ratio of broilers fed control and diets containing different level of Hwangto supplementation (P>0.05). There were no significant differences in TBA value of meat from broilers fed control and Hwangto supplemented diets (P>0.05). The meat cholesterol content was significantly lower in Hwangto treatment than of the control (P>.0.05). $NH_3$ concentration in feces was reduced in all Hwangto treatments (P<0.05). The Mg and Mn concentrations of meat we.e significantly higher in 8.0% Hwangto treatment than that of the control (P<0.05). The large intestine weight was significantly reduced in 2.0, 4.0 and 8.0% treatments (P<0.05).