• Journal of the Korean Chemical Society
• /
• v.47 no.3
• /
• pp.199-205
• /
• 2003

Complexes of uranyl ion $UO^{+2}_2$with Schiff-bases obtained by condensing glycylglycine with salicylaldehyde; 2-hydroxy-1-naphthaldehyde, 2,3-dihydroxybenzaldehyde, and 2,4-dihydroxybenzaldehyde have been synthesized and characterized through elemental analysis, conductivity measurements, magnetic susceptibility determinations, u.v., i.r. and $^1H$ nmr spectra as well as d.t.a., t.g. and d.s.c. techniques. Structures and mechanisms of thermal decomposition are proposed.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2006.04a
• /
• pp.1048-1055
• /
• 2006

Two ways can be used for dynamic condensation of viscously damped structural models. One is reducing the model in physical space at first and then transferring it to state space. The other is ,condensing the model in state space directly. Two iterative schemes for each way are given respectively. Hence four iterative schemes for dynamic condensation of nonclassically damped models are discussed in this paper. A high building with a tuned mass damper is applied to show the efficiency of these schemes.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.1283-1287
• /
• 2009

In this study, an analysis was performed on an evaporative steam generator (concentrator), where natural circulation convective boiling occurs on tube-side by condensing hot steam on shell-side. Existing correlations on two-phase pressure drop, boiling or condensation heat transfer were used for the analysis. The effect of number of tubes, tube length, etc. on thermal performance was investigated. Simulation results reveal that steam generation rate increases almost proportionally to the tube length, or number of tubes. It is also shown that water circulation rate decreases as tube length increases.

• Textile Coloration and Finishing
• /
• v.3 no.3
• /
• pp.23-28
• /
• 1991

Poly(1, 4-cyclohexanedimethylene/ethylene terephthalate), PCET was prepared by condensing 1, 4-cyclohexanedimethanol(CHDM) and ethylene glycol with dimethylterephthalate(DMT), and some thermal properties of PCET were studied by DSC at a heating rate $20^{\circ}C$min. On increasing the CHDM content in PCET up to 20 mole%/DMT, the glass transition temperature(Tg) decreased a little and the crystallizability reduced sharply, and from 20 to 50 mole %/DMT the $T_g$ did not changed and the crystallization temperature was not detected. But on increasing the CHDM content above 70 mole %/DMT the TEX>$T_g$/ and the melting temperature increased.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.11a
• /
• pp.260-263
• /
• 2007

The importance of natural light in building is known by all of us who experienced dark rooms. The sunlight system is very important from energy saving and human welfare point of view. The system consists of light-collecting module, light -transporting module and light-emitting module. The light-collection is used light reflection mirror, a prism for lighting bent, and lens for light condensing. The transportation of collected sunlight is used polished duct, tube, pipe and specially used fiber optic cable. This paper investigate research and development trends of sunlight system for advanced product.

• Journal of Advanced Marine Engineering and Technology
• /
• v.22 no.6
• /
• pp.871-879
• /
• 1998

The refrigerator consists of many components such as compressor condenser expansion valve evaporator and the cabinet which filled by urethane foam. In this paper the heat leakage of refriger-ator is measured by the new experiment method which is different from a present method, The devi-ation of the UA(overall heat transfer coefficient times area) between the simulation and experiments is about 7-8%. Using the modeling of various components of refrigeration system a performance analysos of CFC 12 and HFC 134a is performed numerically on the UA. As the results of this study according to increase the heat leakage the refrigeration load and mass flow rate of refrigerant are increased. And the increase of the mass flow rate results in the increase of the condensing and evapo-rating temperature. Therefore according to increase of the heat leakage the COP leads to increase because the increase of refrigeration capacity is larger than the increase if compressor power.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.1-6
• /
• 2000

In this study, We evaluated the Performance of PFC and the system performance of large size air-conditioner applying to outdoor condenser. PFC can meet the same cooling capacity in 40.42% of volume to fin-tube condenser. Although the fin-tube condenser requires 3600g of refrigerant charging, PFC requires 1700g, 1800g, 1900g, 2000g refrigerant charging for each 2.0mm, 2.5mm, 3.0mm and 3.5mm fin pitches. Difference of condensing and evaporation pressure is the biggest point 2.0mm fin pitch and the smallest point 2.5mm fin pitch.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.700-705
• /
• 2003

The general cooling tower is a device for making a cooling water in refrigerant condensers or industrial process heat exchangers. The present cooling tower have defects with noises, complicated structure and environmental problems. In this paper, we constituted a new water cooling system by using a evaporating latent heat in an enclosed tank, and this system is consisted of an enclosed vacuum tank and water driving ejector system. Several experimental cases were carried out for improvement methods of high vacuum pressure and water cooling characteristics. The ejector performance was tested in case of water temperature variations that flows in the ejector. Based on the vacuum pressure by water driving ejector, the water cooling characteristics were investigated for the vaporized air condensing effects.

• 한국연소학회:학술대회논문집
• /
• 2012.04a
• /
• pp.89-91
• /
• 2012

In this study, an investigation into the gas interchangeability and combustion characteristics of natural gas with various compositions was performed. In order to suggest the appropriateness of gas interchangeability using the specific gravity(SG) and the Wobbe index(WI) values, combustion characteristics, which include incomplete combustion and flame lifting, were measured and observed for the upper and lower limits using the gas-oven as a domestic partial-premixed type appliance and the condensing boiler as a domestic premixed type appliance.

• Biomolecules & Therapeutics
• /
• v.6 no.3
• /
• pp.256-260
• /
• 1998

-7-o-p-Fluorobenzoylchrysin was synthesized by condensing p-flouorbenzoic acid with chrysin in organic solvent, and its structure was identified by NMR, MS, UV, and IR. We also investigated the physicochemical properties, hypoglycemic effect, and the quantitative analysis method of this compound. The correlation coefficient of calibration curve on this compound was approximately 0.9945 by absorption spectrophotometry and 0.9989 by high perfornance liqid chromatography 7-o-p-Fluorobenzoylchrysin was resolved in 6.014 min by reversed-phase HPLC column with solvents consisting of methanol (80%) and 10mM phosphoric acd. Its blood glucose inhibition rate is 20.7%.