• Journal of Institute of Control, Robotics and Systems
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• v.11 no.10
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• pp.870-879
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• 2005

This paper presents that a transient response can be characterized by certain parameters which are correlated to characteristic polynomial coefficients. These are characteristic ratios and characteristic pulsatances by P. Naslin [4]. We have developed an approach to control directly the transient response. Firstly, speed of the response can be controlled by reconstruction form via multipliable characteristic pulsatances. Secondly, overshoot is controlled by reconstruction form via multipliable characteristic ratios. These formulas can be independently characterized by the system overshoot and the response time to a step input.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1143-1156
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• 2017

This paper describes recent development activities of the GENESIS code, which is a transport code for heterogeneous three-dimensional geometry, focusing on applications to reactor core analysis. For the treatment of anisotropic scattering, the concept of the simplified Pn method is introduced in order to reduce storage of flux moments. The accuracy of the present method is verified through a benchmark problem. Next, the iteration stability of the GENESIS code for the highly voided condition, which would appear in a severe accident (e.g., design extension) conditions, is discussed. The efficiencies of the coarse mesh finite difference and generalized coarse mesh rebalance acceleration methods are verified with various stabilization techniques. Use of the effective diffusion coefficient and the artificial grid diffusion coefficients are found to be effective to stabilize the acceleration calculation in highly voided conditions.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.129-139
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• 2018

The effects of N doping concentration and dopant moieties on the electrochemical properties of nanoporous graphene and their dependence on annealing temperature are investigated. Four types of N moieties - amide, amine, graphitic-N, and oxidized-N - are obtained, which transformed into pyridinic-N and pyrrolic-N upon annealing. The diffusion coefficient (D') of the ions in the electrode is the maximum at $400^{\circ}C$ because of a high level of N doping, whereas the second highest D0 value is obtained at $700^{\circ}C$ owing to a high level of reduction and N doping. The highest specific capacitance is obtained for the sample annealed at $400^{\circ}C$.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.731-736
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• 2006

Groundwater heat pump (GWHP) system has been expected to achieve the higher coefficient of performance (COP) and more energy-saving than the conventional air-source heat pump (ASHP) system. Its performance significantly depends on the characteristics of groundwater and the underground thermal properties. Furthermore, there is a large difference of COP in utilizing groundwater between as a heat resource and as a thermal storage medium. For properties of groundwater there is suitable utilizing system. However, many of GWHP systems have not been considered sufficiently such properties. This research describes optimization of GWHP system according to the properties of groundwater based on 3D numerical heat and water transport simulation.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1615-1617
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• 2009

The water resources project of 320 Ha second stage reclamation, in which including an University City, out of 800 Ha Ndata Farm, Malawa, had been under studied in this research. The challenge of C value of runoff coefficient was obtained as 0.8, by introducing the attenuation factors method, proposed by second author, an IDF dimensionless method customary used in Taiwan, proposed by the third author, is translated further to solve the project design rainfall; Rational Method, thus, obtains 11.5 CMS as the 5 year recurrence storage. The final job, completed by the third author's on-site performance, includs field alignments and discussions with the trustee, Malawa President H. E. Dr. Bingu Wa Mutharika, when a special concern of anti-theft. In order to provide sufficient supply up to an amount of 44,000 M3 during April to November, the sketch package includes 6 measurements: one water barrage, one sluice gate, one intake, one sediment reservoir, one water reservoir, and 3199 Km long gravity-driving hydraulic pipe.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.224-232
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• 1999

Latent heat storage system using micro-encapsuled phase change material is effective method for floor heating of house and building. The temperature profile in capsule block and flow rate of hot water are important parameters for the development of heat storage system. In the present study, a mathematical model based on 3-D, non-steady state, Navier-Stokes equations, scalar conservation equations and turbulence model ($\kappa$-$\varepsilon$), is used to predict the temperature profiles in capsule and the velocity vectors in hot water pipe. The multi-block grids and fine grids embedding are used to join the circle in hot water pipe and square in capsule block. The phase change process of the capsule is quite complex not only because the size of phase change material is very small, but also because phase change material is mixed with the cement to form thermal storage block. In calculation, it's assumed that the phenomena of phase change is limited only the thermal properties of phase change material and the change of boundary is not happened in capsule. The purpose of this study is to calculate the temperature profiles in capsule block and velocity vectors in hot water pipe using the numerical calculation. Two kinds of thermal boundary condition were considered, the first (case 1) is the adiabatic condition for the both outside surfaces of the wall, the second (case 2) is the case in which one surface is natural convection with atmosphere and another surface is adaibatic. Calculation results are shown that the temperature profile in capsule block for case 1 is higher than that for case 2 due to less heat loss in adaibatic surface. Specially, in the domain of near Y=0, the difference of temperature is greater in case 1 than in case 2. The detailed experimental data of capsule block on the temperature profile and the thermal properties such as specific heat and coefficient of heat transfer with the various temperature are required to predict more exact phenomena of heat transfer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.5
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• pp.467-472
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• 2013

A raw-water source heat pump equipped with a thermal storage tank was dynamically simulated by TRNSYS, and the results were verified by using the data from a heat pump installed in the Seongnam water treatment facility. The average coefficient of performance (COP) of the raw-water source heat pump based on simulation was 4.97 and 3.17 in the cooling and heating season, respectively. When the volume of the thermal storage tank was changed from 5 to $20m^3$, the highest COP was found at a size of $10m^3$. Considering the regional locations of raw-water source heat pumps at Seoul, Incheon, Gangneung, and Gwangju, Seoul showed the lowest electric power consumption in the cooling season and the highest in the heating season. When a comparison of the performance between the present system and that of a water-air heat pump was conducted, the present system showed lower electric power consumption by 25% than that of a water-air heat pump.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.130-136
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• 1986

'Shingo' pears were seal-packaged in polyethylene (PE) film with different thickness of 0.04. 0.06, 0.07, and 0.08mm and stored for five months in an experimental storehouse with the temperature varyine 0 to $7^{\circ}C$ and relative humidity varying 86 to 89%. The atmosphere in PE film bags was modified to 5-l4% oxygen with 3-5% carbon dioxide depending on the film thickness and the storage period. Packaging of pears with PE film effectively reduced the weight loss, which resulted in good appearance after 5 months' storage, while non-packaged pears showed a slight wilt. Decay occurrence was not significantly different among the treatments. but role browning occurred a little more in packaged lots than in non-packaged lot. The sensory panel rated the pears front 0.07mm-thick bag highest in flavor, texture, and juiciness, which might be due to the high sugar content and low titratable acidity. The firmness of pear flesh decreased with the stogare time and its change was found to be highly correlated with that of cellulase activity (correlation coefficient= -0.946). Thisresult indicated that cellulase might be one of the enzymes responsible for the softening of pear fruit during storage.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.643-649
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• 2004

Pork was cooked using three kinds of instrument [electric pill (EG) for 5min., microwave oven (MW) for 6min. and reheated using a MW] and then extracted with $80\%$ methanol. The Ames test was performed on the methanol extracts, employing the S. typhimurium tester strain, TA100. The methanol extract of cooked pork showed high mutagenicity ion the 5.0 mg/plate without the S9 mix, but a higher mutagenicity was induced with the S9 mix With increasing refrigeration $(4^{\circ}C)$ and freezing $(-18^{\circ}C)$ periods the extracts showed higher mutagenicities and TBA values, and the same results where shown with reheating. Correlations of the mutagenicity (-S9 mix) and rancidity of the pork cooked by EG, according to storage at and $-18^{\circ}C$ and reheated by MW (1 min), were r=0.85, 0.86, 0.98 and 0.83, respectively. When the MW was used for reheating, the refrigeration storage (r=0.98) showed a higher correlation coefficient than for that stored frozen (r=0.83). From the structure of cooked pork, as observed by SEM, many vapor pathways were viewed in the pork reheated using themicrowave oven.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.46-52
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• 2006

The effects of surface treatment on the hydrogen storage properties of a $Mg_2Ni$ alloy particle were investigated by the microvoltammetric technique, in which a carbon-filament microelectrode was manipulated to make electrical contact with the particle in a KOH aqueous solution. It was found that the hydrogen storage properties of $Mg_2Ni$ at room temperature were improved by the surface treatment with a nickel plating solution. The sodium salts(sodium phosphate and sodium dihydrogen citrate) contained in the nickel plating solution made the alloy form an amorphous-like state, resulting in an improved hydrogen charge/discharge capacity at room temperature as high as about 150[mAh/g] from the original value of 17[mAh/g]. Potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-8}{\sim}10^{-9}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process.