• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.3
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• pp.158-168
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• 2015

To create an ultra-high vacuum state at the KSTAR, the temperature of plasma facing component and vacuum vessel should be maintained at $300^{\circ}C$ and $110^{\circ}C$ respectively at a baking phase. The purpose of this research is obtaining the target baking temperatures. Experiments were performed to investigate the temperature characteristics of PFC and VV at the baking phase. Thermal network analysis was used to find heat transfer rates among PFC, VV and other components, and this analysis was verified by using the experimental data. The required heating energy of the PFC and the heating and cooling energy of the VV for the target baking temperatures were found to be 346 kW, 28 kW, and 136 kW, respectively.

• Progress in Superconductivity and Cryogenics
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• v.6 no.2
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• pp.11-14
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• 2004

YBCO thin films have good characteristics for current limiting materials due to compact size and high current carrying capability. But the irregularities and the extreme thin thickness of YBCO films cause some difficulties in simultaneous quench and thermal shock protection. In order to solve these problems, vertical magnetic field generated from solenoid coil was applied to the YBCO element. And also to minimize the inductance caused by the serial connection of magnetic field source with superconducting elements, magnetic field source was separated from the power lines adapting protective current transformer. In this study, electric field-current (E-I) and quench characteristics of YBCO films were analyzed both by electrical measuring method and observations of bubble propagation. From the experiment results, it was revealed that the magnetic fields generated by surrounding coil could induce the uniform quench distribution for all stripes of current limiting units and finally simultaneous quenches were realized in all serial connection of YBCO elements. In addition, the separation of magnetic field source form electrical network could be good solution for simultaneous quench of YBCO films without any unnecessary effect caused by serial connection.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.5
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• pp.604-611
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• 2004

Simulation of three-dimensional turbulent flow with LES and DNS lakes much time and expense with currently available computing resources and requires big computing resources especially for high Reynolds number. The emerging alternative to provide the required computing power and working environment is the Grid computing technology. We developed the CFD code which carries out the parallel computing under the Grid environment. We constructed the Grid environment by connecting different PC-cluster systems located at two different institutes of Pusan National University in Busan and KISTI in Daejeon. The specification of PC-cluster located at two different institutes is not uniform. We run our parallelized computer code under the Grid environment and compared its performance with that obtained using the homogeneous computing environment. When we run our code under the Grid environment, the communication time between different computer nodes takes much larger time than the real computation time. Thus the Grid computing requires the highly fast network speed.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.131-136
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• 2004

The effects of salt concentration and heating conditions on the thermal gelation properties of surimi produced from mechanically deboned chicken meat (MDCM) were investigated. Chicken surimi was manufactured by washing (MDCM: 0.5% NaCl=1:4), standing, straining and centrifuging. The fat, water-soluble protein and heme pigment in the MDCM were removed by increasing washing cycles. The compressive force of the chicken surimi increased as the concentration of salt was increased from 0% to 5%. Total gel strength of the surimi measured by texture profile analysis showed a maximum in the range 3-5% NaCl. Microstructural analysis showed that the unfolding network structure of the surimi gel began to appear at NaCl concentrations>2%. The optimum heating condition for gelation was $90^{\circ}C$ for 40 min as this resulted in maximum values for measures of gel strength including compressive force, hardness, fracturability, adhesiveness, springiness, gumminess, chewiness and resilience. Chicken surimi gel formed by cooking at a heating rate of $1^{\circ}C/min$ to $90^{\circ}C$ showed better a texture than gels produced at $1.85^{\circ}C/min$. Our result show that a lower rate of heating improves chicken surimi gelation.

• Annual Conference of KIPS
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• 2016.10a
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• pp.874-875
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• 2016

This paper proposes the architecture and major functionalities of IT converged smart outdoor exercise equipment and health cashback system. It provides basic information such as date, time, weather information, and display the amount of exercise, thermal images for monitoring the change of user's body temperature and health cashback point. The amount of exercise is transferred to a health cashback server via mobile communication network and the server provides the exercise history and health cashback point. Also, as additional public services, a fine dust alarm light and an emergency alarm function are embedded. The proposed IT converged smart outdoor exercise equipment will be a reference model for studying and commercializing the next generation product.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.229-230
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• 1998

Triblock copolymers from poly(ethylene glycol) (PEG) and D,L-lactide or $\varepsilon$-carprolactone were synthesized to prepare semi-interpenetrating polymer network (semi-IPN) with chitosan by U.V. irradiation method. Then, solute permeation through these semi-IPNs hydrogels were investigated. The structures of semi-IPNs were confirmed by FT-IR spectroscopy and wide angle X-ray diffractometer (WAXD). Equilibrium water content (EWC) of these hydrogels was in the range of 67-75%. The crystallinity, thermal properties and mechanical properties of semi-IPNs hydrogels were studied. All the hydrogels revealed a remarkable decrease in crystallinity as compared with PEG macromer itself. The tensile strengths of semi-IPNs hydrogels in dry state were rather high, but those of hydrogels in wet state decreased drastically. The permeabilities of solutes of hydrogels followed the swelling behaviors and were regulated by solute size.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.167-171
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• 2012

Ag- and Pd-loaded $SnO_2$ nanowire network sensors were prepared by the growth of $SnO_2$ nanowires via thermal evaporation, the coating of slurry containing $SnO_2$ nanowires, and dropping of a droplet containing Ag or Pd nanoparticles, and subsequent heat treatment. All the pristine, Pd-loaded and Ag-loaded $SnO_2$ nanowire networks showed the selective detection of $C_2H_5OH$ with low cross-responses to CO, $H_2$, $C_3H_8$, and $NH_3$. However, the relative gas responses and gas selectivity depended closely on the catalyst loading. The loading of Pd enhanced the responses($R_a/R_g$: $R_a$: resistance in air, $R_g$: resistance in gas) to CO and $H_2$ significantly, while it slightly deteriorated the response to $C_2H_5OH$. In contrast, a 3.1-fold enhancement was observed in the response to 100 ppm $C_2H_5OH$ by loading of Ag onto $SnO_2$ nanowire networks. The role of Ag catalysts in the highly sensitive and selective detection of $C_2H_5OH$ is discussed.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.182-188
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• 2014

Three new transition metal complexes based on Ozagrel $[Cu(Ozagrel)]_n$ (1), $[Zn(Ozagrel)(Cl)]_n$ (2), ${[Mn_2-(Ozagrel)(1,4-ndc)_2]{\cdot}(H_2O)}_n$ (3), (Ozagrel = 3-(4-((1H-imidazol-1-yl)methyl)phenyl)acrylic acid; 1,4-ndc = 1,4-Naphthalenedicarboxylic acid) have been hydrothermally synthesized and characterized by elemental analyse, IR, TG, PXRD, electrochemical analysis and single crystal X-ray diffraction. X-ray structure analysis reveals that 1 and 3 are 3D coordination polymers, while complex 2 is a two-dimensional network polymer, the 2D layers are further packed into 3D supramolecular architectures that are connected through hydrogen bonds. The electrochemistry of 1-3 was studied by cyclic voltammetry in methanol and water using a glassy carbon working electrode. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1603-1606
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• 2009

A new 1D oxalato bridged compound Ni(en)(ox)-2$H_2$O, (ox = oxalate; en = ethylenediamine) has been hydrothermally synthesized and characterized by single crystal X-ray diffraction, IR spectrum, TG analysis, and magnetic measurements. In the structure the Ni atoms are coordinated with four oxygen atoms in two oxalate ions and two nitrogen atoms in one ethylenediamine molecule. The oxalate anion acts as a bis-bidentate ligand bridging Ni atoms in cis-configuration. This completes the infinite zigzag neutral chain, [Ni(en)(ox)]. The interchain space is filled by water molecules that link the chains through a network of hydrogen bonds. Thermal variance of the magnetic susceptibility shows a broad maximum around 50 K characteristic of one-dimensional antiferromagnetic coupling. The theoretical fit of the data for T > 20 K led to the nearest neighbor spin interaction J = -43 K and g = 2.25. The rapid decrease in susceptibility below 20 K indicate this compound to be a likely Haldane gap candidate material with S = 1.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.345-354
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• 2009

Sulfonated poly(ether sulfone)s (PESs) with a network structure were prepared by heat-induced crosslinking of the allyl-terminated telechelic sulfone polymers using a bisazide and their structure was analyzed by $^1H$ NMR. Having both uniform distribution of the hydrophilic conductive sites and controlled hydrophobic nature by minimized crosslinking, the crosslinked polymer (PES-60) membrane offered excellent proton conductivity at high temperature with a good thermal stability. In addition, selectivity of the crosslinked membrane (PES-60) was more than three times than that of Nafion$^{(R)}$.