• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.4
• /
• pp.558-563
• /
• 2013

The present study was conducted to estimate energy requirements for maintenance in laying hens by using indirect calorimetry and energy balance. A total of 576 28-wk-old Nongda-3 laying hens with dwarf gene were randomly allocated into four ME intake levels (86.57, 124.45, 166.63 and 197.20 kcal/kg body weight $(BW)^{0.75}$ per d) with four replicates each. After a 4 d adaptation period, 36 hens from one replicate were maintained in one of the two respiration chambers to measure the heat production (HP) for 3 d during the feeding period and subsequent 3 d fast. Metabolizable energy (ME) intake was partitioned between heat increment (HI), HP associated with activity, fasting HP (FHP) and retained energy (RE). The equilibrium FHP may provide an estimate of NE requirements for maintenance (NEm). Results showed that HP, HI and RE in the fed state increased with ME intake level (p<0.05). Based on the regression of HP on ME intake, the estimated ME requirements for maintenance (MEm) was 113.09 kcal/kg $BW^{0.75}$ per d when ME intake equals HP. The FHP was decreased day by day with the lowest value on the third day of starvation. Except for lowest ME intake level, the FHP increased with ME intake level on the first day of starvation (p<0.05). The FHP at the two higher ME intake levels were greater than that at the two lower ME intake levels (p<0.05) but no difference was found between the two lower ME intake levels. Linear regression of HP from the fed state to zero ME intake yielded a value of 71.02 kcal/kg $BW^{0.75}$ per d, which is higher than the extrapolated FHP at zero ME intake (60.78, 65.23 and 62.14 kcal/kg $BW^{0.75}$ per d for the first, second and third day of fasting, respectively). Fasting time, lighting schedules, calculation methods and duration of adaptation of hens to changes in ME intake level should be properly established when using indirect calorimetry technique to estimate dietary NE content, MEm and NEm for laying hens.

• BMB Reports
• /
• v.28 no.5
• /
• pp.408-413
• /
• 1995

Decrease in the amount of cotyledonary spermidine in Glycine max under anaerobic conditions related to an increase in spermidine dehydrogenase. Under the same conditions, no enzymatic activity of diamine oxidase was observed. Exposure of Glycine max both to spermidine and 1,3-diaminopropane under anaerobic conditions resulted in a decrease in spermidine contents. Correlated with the decrease in spermidine contents, there was a drastic increase in spermidine dehydrogenase. The molecular weight of the purified enzyme estimated by Sephacryl S-300 gel column and SDS gel electrophoresis were 130,000 dalton and 65,000 dalton, respectively, indicating that the enzyme is a dimer. The optimal pH for activity was 9.3. The $K_m$ value for spermidine was 0.61 mM. Neither metal ions nor polyamine and derivatives affected enzymatic activity, but the enzyme was inhibited by DTNB, NEM and PCMB, suggesting that a cysteine residue of the enzyme is associated with or involved in enzyme activity. To our knowledge, this is the first report describing properties of the enzyme from plants. Considered together, the data in this paper indicate that both spermidine and 1,3-diaminopropane, novel activators, enhance the spermidine dehydrogenase activity and control the intracellular spermidine contents.

• The Journal of Korean Medicine
• /
• v.24 no.4
• /
• pp.34-42
• /
• 2003

This study was designed to investigate the modulation of the Corydalis tuber on glycine-activated ion current in rat periaqueductal gray (PAG) neurons. Aqueous extract from Corydalis tuber has been widely used for pain control such as dysmenorrhea, irregular menstruation or amenorrhea with abdominal cramping, neuralgia, headache and gastrointestinal spasm. The PAG region of the brain is known to be involved heavily with nociception. Modulation of the Corydalis tuber on glycine-induced ion current in rat periaqueductal gray (PAG) neurons was studied by a nystatin-perforated patch-clamp technique. High concentrations of Corydalis tuber elicited ion current, which was suppressed by strychnine application. Low concentrations of Corydalis tuber reduced glycine-induced ion currents in the PAG neurons. Inhibitory action of Corydalis tuber on glycine-activated ion current was reduced by treatment with naltrexone, a non- selective opioid antagonist. Application of N-methylmalemide (NEM), a sulfhydryl alkylating agent, also reduced the inhibitory action of Corydalis tuber on glycine-activated ion current in the PAG neurons. These results suggest that the inhibitory effect of Corydalis tuber on glycine-activated ion current in the PAG neurons is one of the analgesic mechanisms of the Corydalis tuber, which may activate descending pain control system in PAG neurons.

• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.1
• /
• pp.59-66
• /
• 1995

Energy obtained by grazing cattle in oil palm plantations is usually used for maintenance of body functions, the construction of body tissues and pregnancy, the synthesis of milk and the conversion to mechanical energy used for activities such as walking, eating and others. In this study, attempt was made to estimate metabolizable energy (ME) requirement of grazing cattle. Models of ME requirement (MER) for maintenance, gain, pregnancy, lactation and activities were developed. ME system and units were used because of wide recognition. Estimation of ME intake in grazing cattle was expressed as MEVI = $14.58{\times}VI{\times}DMD$, and under grazing condition MEVI = $MER_i$. MER was expressed as a function of net energy(NER, MJ) required for the i'th body function. Coefficient of efficiency for conversion of ME into net energy(ki) was adopted from literatures. Quantifying of ME requirement for Kedah-Kelantan cattle under grazing condition was made by using equation MERM = NEM / kn. The estimated values of MER for Kedah-Kelantan cattle is quite reasonable if compared with other estimates as reported in literatures from stall-fed animals. Dynamic MER models for grazing herd was developed in order to estimate ME requirement for maintenance and productions. These ME requirement models can be used for prediction of energy utilization pattern of the herd in the grazing systems.

• The Korean Journal of Physiology and Pharmacology
• /
• v.6 no.2
• /
• pp.63-70
• /
• 2002

Cholinergic modulation of GABAergic spontaneous miniature inhibitory postsynaptic currents (mIPSCs) by the activation of muscarine receptors was investigated in mechanically dissociated rat nucleus basalis of the Meynert neurons using the conventional whole-cell patch recording configuration. Muscarine $(10{\mu}M)$ reversibly and concentration-dependently decreased mIPSC frequency without affecting the current amplitude distribution. Muscarine action on GABAergic mIPSCs was completely blocked by $1{\mu}M$ methoctramine, a selective $M_2$ receptor antagonist, but not by $1{\mu}M$ pirenzepine, a selective $M_1$ receptor antagonist. NEM $(10{\mu}M),$ a G-protein uncoupler, attenuated the inhibitory action of muscarine on GABAergic mIPSC frequency. Muscarine still could decrease GABAergic mIPSC frequency even in the $Ca^{2+}-free$ external solution. However, the inhibitory action of muscarine on GABAergic mIPSCs was completely occluded in the presence of forskolin. The results suggest that muscarine acts presynaptically and reduces the probability of spontaneous GABA release, and that such muscarine-induced inhibitory action seems to be mediated by G-protein-coupled $M_2$ receptors, via the reduction of cAMP production. Accordingly, $M_2$ receptor-mediated disinhibition of nBM neurons might play one of important roles in the regulation of cholinergic outputs from nBM neurons as well as the excitability of nBM neurons themselves.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05c
• /
• pp.423-428
• /
• 1996

The feasibility study on burning Am-241, 243 and Cm-244 nuclides in a conventional PWR (Pressurized Water Reactor) was carried out by using the TRIFON code that was developed by the Institute of Theoretical and Experimental Physics in Russia in 1992. TRIFON code uses updated ABBN Russian nuclear cross section library. The reference reactor is the Korea nuclear power plant unit 8 (YGN 2). The burning effect of Am-241, 243 and Cm-244 nuclides was studied with UO$_2$(3.5 w/o)fuel assembly and MOX (4.44 w/o) fuel assembly. The loaded mass ratio of Am-241, 243 and Cm-244 nuclides was obtained from the mass ratio of Am-241, 243 and Cm-244 nuclides in 10 year cooling spent fuel with average discharge burnup of 33 GWD/MTU. The effective transmutation rates of Am-241, 243 and Cm-244 nuclides in UO$_2$ fuel assembly were found to be higher than those in MOX fuel assembly. The result from TRIFON code was compared to that from CASMO-3/NEM-3D code system. For more reliable calculation of transmutation for MA(Minor Actinides) more sophisticated decay chain scheme of MA should be investigated and nuclear cross section library of MA should be considerably improved.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.13 no.4
• /
• pp.410-414
• /
• 2013

We report the wet etching of titanium nickel (TiNi) films for the production of nano-electro-mechanical (NEM) device. $SiO_2$ and $Si_3N_4$ have been selected as sacrificial layers of TiNi metal and etched with polyethylene glycol and hydrofluoric acid (HF) mixed solution. Volume percentage of HF are varied from 10% to 35% and the etch rate of the $SiO_2$, $Si_3N_4$ and TiNi are reported here. Within the various experiment results, 15% HF mixed polyethylene glycol solution show highest etch ratio between sacrificial layer and TiNi metal. Especially $Si_3N_4$ films shows high etch ratio with TiNi films. Wet etching results are measured with SEM inspection. Therefore, this experiment provides a novel method for TiNi in the nano-electro-mechanical device.

• Nuclear Engineering and Technology
• /
• v.31 no.4
• /
• pp.401-407
• /
• 1999

We have performed two experiments in the fast critical assembly BFS to measure the effective delayed neutron fraction $\beta$$_{eff}$ values and compared the results to validate the $\beta$$_{eff}$ computation code, BETA-K. Measurements of $\beta$$_{eff}$ were carried out in a metallic plutonium core and a metallic uranium core with Cf$^{252}$ source pseudo-reactivity method. Fission integrals and correction factors, which were used to obtain the experimental $\beta$$_{eff}$ values, were calculated by using the LMR core design computation code system of KAERI. BETA-K has been developed consistently with the hexagonal Nodal Expansion Method (NEM) and it used delayed neutron data of ENDF/B-VI. By comparing the computed $\beta$$_{eff}$ values with the measured ones, we found that the results from BETA-K agreed with the experimental values within the experimental error bound.ror bound.

• Structural Engineering and Mechanics
• /
• v.88 no.5
• /
• pp.439-449
• /
• 2023

Non-linear vibration characteristics of functionally graded CNT-reinforced composite (FG-CNTRC) cylindrical shell panel on elastic foundation have not been sufficiently examined. In this situation, this study aims at the profound numerical investigation of the non-linear vibration response of FG-CNTRC cylindrical panels on Winkler-Pasternak foundation by introducing an accurate and effective 2-D meshfree-based non-linear numerical method. The large-amplitude free vibration problem is formulated according to the first-order shear deformation theory (FSDT) with the von Karman non-linearity, and it is approximated by Laplace interpolation functions in 2-D natural element method (NEM) and a non-linear partial derivative operator H_NL. The complex and painstaking numerical derivation on the curved surface and the crucial shear locking are overcome by adopting the geometry transformation and the MITC3+ shell elements. The derived nonlinear modal equations are iteratively solved by introducing a three-step iterative solving technique which is combined with Lanczos transformation and Jacobi iteration. The developed non-linear numerical method is estimated through the benchmark test, and the effects of foundation stiffness, CNT volume fraction and functionally graded pattern, panel dimensions and boundary condition on the non-linear vibration of FG-CNTRC cylindrical panels on elastic foundation are parametrically investigated.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.380-381
• /
• 2011

전력거래소는 2014년 나주본사이전 이후 1억kW 대용량 전력계통을 운영하기 위한 차기 계통운영시스템(이하 차기EMS) 구축을 계획하고 있다. EMS(Energy Management System)는 전국의 발, 변전소에서 계통정보를 실시간으로 취득하여 전력계통을 감시하며, 연료비 기반의 최적 경제점을 찾아 발전기를 제어하고, 전력계통을 수식화한 상태추정 결과를 기반으로 상정사고분석, 고장전류계산 등 전력계통운영을 위한 종합시스템이다. 국내 EMS의 역사는 1979년 미국의 L&N 시스템 도입을 시작으로 1988년 일본의 Toshiba EMS, 2001년 Alstom사의 NEMS를 구축하여 현재 운영중에 있다. 하지만, 외산 제품 도입에 따른 기술이전, 유지보수의 어려움을 타개하기 위해 2004년 한국형 EMS(이하 K-EMS) 연구개발계획을 수립하고 전력거래소를 주축으로 한 산학연을 구성하여 2010년 K-EMS 개발을 성공적으로 완료하였다. 차기 EMS는 국내 기술력으로 개발된 정부연구과제 성과물인 K-EMS를 기반으로 구축이 이루어지며, 총 3년간의 개발 및 시험과정을 거쳐 실계통운영을 담당할 예정이다. 차기EMS가 설치되어 운영예정인 급전소는 전력수급 균형유지와 발전소 운영 총괄 지휘 및 765kV, 345kV 송전망 운영역할을 담당할 나주급전소와 154kV 비수도권 송전망 운영을 담당할 천안급전소, 154kV 수도권 송전망 운영을 책임질 서울급전소 이상 3곳이다. 차기EMS는 발전 및 송, 변전 설비의 대형화, 다양한 FACTS 설비, 신재생에너지원으로 대표되는 분산전원의 등장과 같은 급변하는 전력계통 변화에 능동적인 역할을 성공적으로 수행할 것으로 기대하고 있다.