• Asian-Australasian Journal of Animal Sciences
• /
• 제16권12호
• /
• pp.1725-1731
• /
• 2003

Effect of strategically supplemented pregnancy allowance was ascertained during different phases of gestation on the reproductive performance of does. Gravid does (18) were allotted to 3 dietary treatments HH, HL and LH in a completely randomized block design. All does were provided wheat straw ad libitum and supplemented with concentrate mixture at the rate of $20g/kgW^{0.75}$ from 0-60 days post-mating. Subsequently, HH group was given concentrate at the rate of $40g/kgW^{0.75}$ from 61 d post-mating to term. HL group was offered concentrate from 61-90 d post-mating and 121d post mating to term at the rate of $20g/kgW^{0.75}$ and from 91-120 d post-mating at the rate of $40g/kgW^{0.75}$. LH group was provided with concentrate from 61 to 120 d post-mating and 121 to term at the rate of 20 g and $40g/kgW^{0.75}$, respectively. Mean total dry matter and concentrate intake ($g/kgW^{0.75}$) was significantly higher on HH in comparison to comparable intake of HL and LH treatments, however, wheat straw followed the reverse trend. Haematological and biochemical parameters except serum glucose, total serum protein and A:G ratio did not differ significantly among dietary treatments. The gross gain in weight, products of pregnancy at 21 weeks of gestation, pregnant does average daily gain, birth weight of kids and survivability of kids were significantly lower in treatment HL in comparison to comparable values for HH and LH treatments. The net gain in gravid does was significantly higher in treatment HH than the comparable values obtained in HL and LH treatments. The last month of pregnancy was found to be nutritionally most sensitive period of gestation for native goats.

• Nuclear Engineering and Technology
• /
• 제39권2호
• /
• pp.123-128
• /
• 2007

In order to apply a static fault-tree (FT) method to a system or a plant whose configuration changes dynamically, condition gates and a post processing method are used to effectively accommodate these changes. An operator's performance change, which can be caused by these configuration changes, should also be considered to assess the risk to a plant in a more realistic manner. This study aims to develop an integrated framework to accommodate various configuration changes and their effect on an operator’s performance by using the FT model. We applied a condition-based human reliability assessment (CBHRA) method to consider various conditions endured by an operator. That is, we integrated the CBHRA method with the conventional post processing method for modeling the system configuration changes. The effect of the condition monitoring systems installed in a plant is also considered. In this study, we show an example application of the integrated framework to a probabilistic safety assessment for the shutdown phase of a nuclear power plant.

• 산업공학
• /
• 제21권1호
• /
• pp.120-130
• /
• 2008

In this paper, we develop a transportation planning system for the mail transportation network, which consists of 25 mail centers and one mail exchange center. The main functions of the system are adjustment of transportation plan, creation of new transportation plan, and calculation of expected exchange mail volume which are transported through mail exchange center. We develop an adjusting algorithm which gives a new transportation plan by deleting, adding or changing the current routes. The algorithm based on the transportation results of current transportation plan and mail volume data. We design and implement a planning system by installing the algorithm as the planning engine. For the practical use, the system is connected to the information system of Korea Post, PostNet.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
• /
• pp.88-93
• /
• 1994

The mechanisms controlling the intensity and duration of synaptic transmission are numerous. Once an action potential reaches a nerve terminal, the stored neurotransmitters are released in a quantum fashion into the synaptic cleft. At that point neurotransmitters can act on post-synaptic receptors to elicit an action on the post-synaptic cell or net at so-called auto-receptors that are located on the presynaptic side and which often regulate the further release of the neutotransmitter. Whereas the action of the neurotransmitter receptors is regulated by desensitization phenomenon, the major mechanism by which the intensity and duration of neurotransmitter action is presumably regulated by either its degradation or its removal from the synaptic cleft. In the central nervous system, specialized proteins located in fe plasma membrane of presynaptic terminals function to rapidly remove neurotransmitters from the synaptic cleft in a sodium chloride-dependent fashion. These proteins have been referred to as uptake sites or neurotransmitter transporters. Once taken up by the plasma membrane transporters, neurotransmitters are repackaged into secretory vesicles by distinct transporters which depend on a proton gradient.

• Nuclear Engineering and Technology
• /
• 제43권6호
• /
• pp.489-498
• /
• 2011

UK National Nuclear Laboratory's (NNL's) version of the ENIGMA fuel performance code is described, including details of the development history, the system modelled, the key assumptions, the thermo-mechanical solution scheme, and the various incorporated models. The recent development of ENIGMA in the areas of whole core analysis and dry storage applications is then discussed. With respect to the former, the NEXUS code has been developed by NNL to automate whole core fuel performance modelling for an LWR core, using ENIGMA as the underlying fuel performance engine. NEXUS runs on NNL's GEMSTONE high performance computing cluster and utilises 3-D core power distribution data obtained from the output of Studsvik Scandpower's SIMULATE code. With respect to the latter, ENIGMA has been developed such that it can model the thermo-mechanical behaviour of a given LWR fuel rod during irradiation, pond cooling, drying, and dry storage - this involved: (a) incorporating an out-of-pile clad creep model for irradiated Zircaloy-4; (b) including the ability to simulate annealing out of the clad irradiation damage; (c) writing of additional post-irradiation output; (d) several other minor modifications to allow modelling of post-irradiation conditions.

• Nuclear Engineering and Technology
• /
• 제51권6호
• /
• pp.1650-1657
• /
• 2019

Fluidelastic instability and nonlinear dynamics of tube bundles is a key issue in a steam generator. Especially, once the post-instability motion of the tube becomes larger than the clearance gap to other tubes, effective contact or impact between the tubes under consideration and the other tube inevitable. There is seldom theoretical analysis to the nonlinear dynamic characteristics of a tube array in two-phase flow. In this paper, experimental and numerical studies were utilized to obtain the critical velocity of the flow-induced instability of a rotated triangular tube array. The calculation results agreed well with the experimental data. To explore the post-instability dynamics of the tube array system, a Runge-Kutta scheme was used to solve the nonlinear governing equations of tube motion. The numerical results indicated that, when the flow pitch velocity is larger than the critical velocity, the tube array system is undergoing a limit cycle motion, and the dynamic characteristics of the tube array are almost similar for different void fractions.

• Nuclear Engineering and Technology
• /
• 제55권2호
• /
• pp.408-420
• /
• 2023

Beryllium oxide (BeO) is being re-emphasized and utilized in Micro Modular Reactors (MMR) because of its prominent nuclear and high temperature properties in recent years. The implications of the research about effects of neutron irradiation on the microstructure and properties of BeO are significant. This article comprehensively reviews the effects of neutron irradiation on BeO and proposes the maximum permissible neutron doses at different temperatures for BeO without cracks in appearance according to the data in the previous literature. This maximum permissible neutron dose value has important reference significance for the experimental study of BeO. The effects of neutron irradiation on the thermal conductivity and flexural strength of BeO are also discussed. In addition, microstructure evolution of irradiated BeO during post-irradiation annealing is summarized. This review article has important implications for the application of BeO in MMR.

• 전자공학회논문지A
• /
• 제31A권2호
• /
• pp.104-115
• /
• 1994

This paper presents the design of a placement sysyem integrated in PCB design system. to get an optimal component positioning from part and net list. Unplaced components are placed in initial process using modified cluster development algorithm and are swapped in improvement process using the GFDR(Generalized Force Directed Relaxation) algorithm. The result is optimized in post process by component rotating or pin/gate swapping. Experimental results shwo that the placement system produces manufacturable layouts which are optimal in terms of total routing length.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.407-408
• /
• 2006

Dimensional precision is a critical parameter in net shape processing of ferrous PM components. Sinter-hardening alloys undergo a transformation from austenite to martensite. Martensite formation expands the sintered compact, while tempering hardened steels results in shrinkage. In addition, martensitic regions with high Cu and C contents may contain large amounts of retained austenite. The presence of martensite and retained austenite, in addition to the tempering step, all play a role in the final dimensions of a component. This paper investigates the dimensional and microstructural changes to two sinter-hardening grades through different post-sintering thermal treatments.

• 한국수소및신에너지학회논문집
• /
• 제28권1호
• /
• pp.30-39
• /
• 2017

Interests in fuel cell based power generation systems are on the steady rise owing to various advantages such as high efficiency, ultra low emission, and potential to achieve a very high efficiency by a synergistic combination with conventional heat engines. In this study, the performance of a hybrid system which combined a molten carbonate fuel cell (MCFC) and an indirectly fired micro gas turbine adopting carbon dioxide capture technologies was predicted. Commercialized 2.5 MW class MCFC system was used as the based system so that the result of this study could reflect practicality. Three types of ambient pressure hybrid systems were devised: one adopting post-combustion capture and two adopting oxy-combustion capture. One of the oxy-combustion based system is configured as a semi-closed type, while the other is an open cycle type. The post-combustion based system exhibited higher net power output and efficiency than the oxy-combustion based systems. However, the semi-closed system using oxy-combustion has the advantage of capturing almost all carbon dioxide.