• Fisheries and Aquatic Sciences
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• v.22 no.10
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• pp.23.1-23.10
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• 2019

Background: Taurine is a conditional essential amino acid for fish. A study was conducted to investigate the compensating effect of supplemental taurine in diets for red seabream (Pagrus major) on impaired growth performance by fish meal (FM) replacement with soybean meal (SM) at low water temperature (14.15 ± 1.95 ℃). Methods: A FM-based diet was considered as a high FM diet and three other experimental diets were formulated to replace FM with SM by 20, 35, or 50% (HFM, SM20, SM35, or SM50, respectively) without taurine and other four diets were formulated by adding 1% taurine to the diets (HFM-T, SM20-T, SM35-T, or SM50-T, respectively). Triplicate groups of fish (108.9 ± 1.58 g/fish) were distributed into 24 polyvinyl circular tanks (215 L) with 20 fish per tank and fed one of the diets to satiation for 20 weeks. Results: Growth performance and feed utilization of red seabream were significantly improved by the dietary taurine supplementation. SM20-T and SM35-T diets increased fish growth that are comparable to HFM diet. Feed intake, feed conversion ratio, and protein efficiency ratio of fish fed SM20-T and SM35-T diets were not significantly different from those of HFM group. Dietary taurine supplementation in each FM replaced group numerically increased innate immunity of the fish. Lysozyme and superoxide dismutase activities were significantly decreased in fish fed SM35, SM50, and SM50-T diets compared to those of fish fed HFM diet while they were not significantly lower in SM20, SM20-T, SM35, and SM35-T groups. Glutathione peroxidase activity was significantly lower in fish group fed SM50 diet while SM50-T group did not significantly lower compared to that of HFM group. The relative expression level of hepatic IGF-1 mRNA was improved in fish fed taurine-supplemented diets compared to their respective SM diets. Conclusions: Growth performance and feed utilization of red seabream can be accelerated or restored by 1% taurine supplementation when they are fed high level of SM up to 35% in diets during low water temperature season.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.9
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• pp.657-662
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• 2022

In this paper, the calculation using simulation and two measurement methods for G/T of the telemetry are analyzed. Antenna gain and noise temperature are calculated by using ICARA and Antenna Noise Temperature Calculator. System G/T were calculated by using Antenna gain/noise temperature, LNA gain/noise temperature, cable loss. The first G/T measurement method is Y-factor measurement method, which is to calculate G/T by comparing LNA noise temperature and a signal level difference when an antenna and a 50ohm termination are respectively connected to an LNA input terminal Second method is Solar calibration measurement method that is to calculate G/T by comparing noise level difference when looking at the sun and lowest level point. Finally, the accuracy was reviewed by comparing the G/T calculation results with the two measurement methods, and the optimal measurement method according to antenna performance and operating environment was presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.105-111
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• 2006

The aircraft engine is to generate thrust for the maneuver of aircraft and to provide the power to the related hydraulic system and electrical system. Since the power provided to the systems is extracted from the high pressure compressor of aircraft engine, the extracted power is called horsepower extraction (HPX). If the HPX provided from the engine is smaller than the HPX required from the related systems, there could be abnormal engine behavior, like engine rollback or stall. Analysis on comparing the required HPX and the engine HPX capability had been performed during the T/A-50 FSD (Full Scale Development) period. The analysis results make the engine schedule changed, and T/A-50 flight test has been performed with the changed engine schedule. The analysis results and changing the engine control schedule were verified to be valid with the flight test results.

• Journal of Korean Society on Water Environment
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• v.24 no.4
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• pp.499-503
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• 2008

In order to control the non-point source pollution, a vegetative filter strips (VFS) was set up and the site-monitoring was performed. The objective of this study is to investigate the influence of the plant coverage on treatment efficiency of total nitrogen (T-N) and total phosphorus (T-P) using vegetative filter strips. According to the results, it seemed that the treatment efficiencies of T-N and T-P were closely related with the plant coverage ratio. The results showed that treatment efficiency of T-P average 50% at higher than 50% of the plant coverage and 20~23% at lower than 50% of the plant coverage. Also, the treatment efficiency of T-N increased with the increase of the plant coverage ratio.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.11
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• pp.106-112
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• 1992

In this paper, we analyze the structure characteristics of $As_{40}Se_{50-x}S_{x}Ge_{10}$ system bulk and thin films. As the results of XRD patterns, it identified amorphous state. In order to find the glass transition temperature($T_g$), crystallization($T_c$) and melting point ($T_m$)of bulk sample, it ascertained that TS1gT is 238$^{\circ}C$ in $As_{40}Se_{15}S_{35}Ge_{10}$, and 231$^{\circ}C$ in $As_{40}Se_{25}S_{25}Ge_{10}$ & $As_{40}Se_{50}Ge_{10}$ following the thernal analysis by DSC, DTA, & TGA method. Also it was confirmed the phase seperation of continuous phase and dispertion phase by the optical texture of polarizing microscope and $T_g$ near 20$0^{\circ}C$ in thin film. Therefore, it was found that it occurs the phase seperation of Ge-rich dontinuous phase and Se-rich dispersion phase following the EDS analysis of thin film and the surface SEM photograph.

• Bulletin of the Korean Mathematical Society
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• v.50 no.5
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• pp.1587-1598
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• 2013

In this paper, we obtain some gradient estimates for positive solutions to the following nonlinear parabolic equation $$\frac{{\partial}u}{{\partial}t}={\triangle}u-b(x,t)u^{\sigma}$$ under general geometric flow on complete noncompact manifolds, where 0 < ${\sigma}$ < 1 is a real constant and $b(x,t)$ is a function which is $C^2$ in the $x$-variable and $C^1$ in the$t$-variable. As an application, we get an interesting Harnack inequality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.305-312
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• 1997

Juveniles of black seabream, Acanthopagrus schlegeli were fed with the diets containing 0, 10, 20, 50 and 100 ppm of 3,5,3'-triiodo-1-thyronine $(T_3)$ respectively to assess the effect of this hormone on skeletal development and the change of physiological conditions for 50 days. $(T_3)$ treatment lasted for initial 40 days. Fish were fed the prescribed diet by hand to satiation in $2\~4$ times per day. After an initial 40 days period, skeletal development and abnormality were examined, and after a 50 days period, food intake, hepatosomatic index (HSI), thyroid cell height (TCH) and body proximate composition were also examined. Although toed intake was not different among 0, 10 and 20 ppm, the food intake of black seabream fed with the diets containing 50 and 100 ppm of $T_3$was significantly lower than those of 10 ppm. After the initial 40 days of $T_3$ administration, $T_3$ increased the relative growth of operculum, head, caudal fin and pectoral fin to body length, resulting in severe morphological abnormalities at the highest dose. Black seabream treated with 50 and 100 ppm of $T_3$ had abnormal shapes such as lordosis and opercular curl. The HSI parameters were reversely correlation with the dietary concentration of $T_3$. After the initial 40 days of this experiment, atrophy of thyroid gland was observed in fish administered with 50 and 100 ppm of $T_3$. On the 50th day of this experiment, atrophy of thyroid gland was observed only in the group administered with 100 ppm of $T_3$, and no difference was observed on TCH among the rest fours of experimental groups. At the end of the experiment the whore body proximate analyses indicated that there were significant effects of $T_3$ level on moisture, protein, lipid and ash contents.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.279-286
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• 2011

The effect of allelochemicals on growth, root nodule nitrogen fixation activity, and ion patterns of soybeans were investigated. We prepared 50 g/L (T50), 100 g/L (T100), and 200 g/L (T200) extract concentrations by soaking fresh red pine needles in a nutrient solution. Adding needles to the nutrient solution increased the content of total phenolic acids, osmolality, and total ions. The total phenolic content in the T50, T100, and T200 extracts were $206{\pm}12.61$, $335{\pm}24.16$, and $603{\pm}12.30$ mg gallic acid equivalents, respectively. The $K^+$, $Mg^{2+}$, $Ca^{2+}$, and $PO_4^{3-}$ content increased by adding needles to the nutrient solutions, whereas $SO_4^{2-}$ content decreased. The growth inhibition of soybeans was proportional to the needle extract concentrations, and the T100 and T200 concentrations resulted in remarkable growth inhibition. On day 20 after treatment, dry weight and nitrogen fixation activity of the root nodules were reduced by the T100 and T200 treatments, whereas the T50 treatment was not difference from the control. After day 10, total ion content in all treatment groups was not different in comparison with the control. However, total ionic content in all treatment groups decreased significantly compared with that in the control after day 20. The lowest total ion value was found for the T200 concentration. The T200 treatment also resulted in significantly reduced $SO_4^{2-}$ content. The amounts of $Mg^{2+}$, $Ca^{2+}$, and $Mn^{2+}$ were higher than those of the control for the T50 treatment on day 10 and for T100 on day 20 after treatment. A significant increase in osmolality was observed in the T200 treatment on day 10 and in the T100 treatment on day 20. These results suggest that under severe allelochemical stress conditions, a remarkable reduction in nodule formation, nitrogen fixation activity, and ion uptake eventually resulted in a decrease in leaf production. Furthermore, increased $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Mn^{2+}$, and osmolality in soybeans exposed to lower concentrations of allelochemicals than the critical stress level helped overcome the stress.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.138-142
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• 2005

Adenosine and GABA are known to be major inhitory neurotransmitters in the central nervous system and its receptors mediate various neurophamacological effects including cardiovascular modulatory effects. Inhibitory cardiovascular effects induced by intrathecal (i.t.) administration of adenosine $A_1$ receptor agonist and its modulation by cyclic AMP was suggested by our previous report. In this experiment, we examined the modulation of cardiovascular effects of adenosine $A_1$ receptor and adenosine $A_2$ receptor by $GABA_B$ receptors antagonist in the spinal cord. I.t. administration of 10 nmol of $N^6$-cyclohexyladenosine (CHA, an adenosine $A_1$ receptor agonist), I.t. administration of 2 nmol of 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA, an adenosine $A_2$ receptor agonist), pretreatment with 5-aminovaleric acid (a $GABA_B$ receptor antagonist, 50 nmol, i.t.) prior to administration of CHA and pretreatment with 5-aminovaleric acid (a $GABA_B$ receptor antagonist, 50 nmol, i.t.) prior to administration of CPCA were performed in anesthetized, artificially ventilated Sprague-Dawley rats. I.t. administration of 50 nmol of 5-aminovaleric acid significantly attenuated the inhibitory cardiovascular effects of CHA but did not attenuated the inhibitory cardiovascular effects of CPCA. It is suggested that cardiovascular responses of adenosine $A_1$ receptor is modulated by $GABA_B$ receptor and adenosine $A_2$ receptor is not modulated by $GABA_B$ receptor in the spinal cord.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.369-378
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• 2012

This study was performed out to investigate the influence of the mixed application of chemical fertilizer (CF) and liquid swine manure (LSM) on the growth characteristics, dry matter yield, amino acids, minerals, and free sugars in cultivating silage corn on paddy soils. The field experiment was designed in a randomized block design of 3 repetitions with CF 100% treatment (C), CF 70% + LSM 30% treatment (T1), CF 50% + LSM 50% treatment (T2), CF 30% + LSM 70% treatment (T3), and LSM 100% treatment (T4). At this time, the application of LSM was based solely on the nitrogen. Ear length, ear circle, stem diameter, and stem hardness of the silage corn did not show significant differences between treatments. Fresh yield, dry matter yield and TDN yield were highest in T3, whereas the lowest in C treatment (p<0.05). Crude protein, crude fat, and crude ash content were significantly higher in T1, C, and T4 treatment, respectively (p<0.05). However, NDF, ADF and crude fiber content did not show significant difference between treatments. The total mineral content decreased significantly (p<0.05) as the LSM application rate increased. Total composition amino acid content was higher in the order of T1 > T2 > C > T4 > T3 treatment (p<0.05). Free sugar content was higher in the order of T1 > T3 > T4 > T2 > C treatment (p<0.05). Based on the above results, suggests that the mixed application of chemical fertilizer 30~50% and LSM 50~70% (T2 and T3) is the most effective, considering the yield performance and the content of sugar degree and free sugar affecting silage.