• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.15 no.2
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• pp.196-203
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• 1986

The melting phenomena of horizontal cylindrical ice-bar immersed in water and air concentrically in the cylinder are experimentally investigated for the temperature range from $3.5^{\circ}C\;to\;2.5^{\circ}C$. The shapes of the melting ice-bar are recorded photographically by the shadowgraph method. The shadowgraphs of the melting ice-bar show that water adjacent to the bar flows upward for the temperature range from $3.5^{\circ}C\;to\;5.8^{\circ}C$ while above $5.8^|\circ}C$ the flow is downward direction. The local and average Nusselt numbers are obtoined with the recorded shadowgraphs and comparator. Melting shapes of the ice-bar in the air show the vortex motion in the bottom portion of the bar, whereas no vortex motion appears in the bottom portion when the bar is melted in the water.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.239-242
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• 2001

Melting and crystallization are not reversible because supercooling is always needed for crystal growth. But, recently reversible melting and crystallization phenomena in semi-crystalline polymers, based on modulated differential scanning calorimetry(MDSC) with quasi-isothermal experiment mode were observed in the melting range and continuously proved by others. (omitted)

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.43-49
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• 2005

Social interest and request about low pollution waste treatment process are growing and gasification melting method, as a new technology concept, is risen. The necessity of engineering analysis to determine design standards and operation condition is required. In this study, the objective and function of components and operation process of various gasification melting furnaces such as shaft type, fluidized bed and Rotary Kiln type gasification melting furnace are reviewed and the design standard and operation range of gasification melting furnace are determined by inspecting the change of output and operation condition with input condition change.

• Journal of Welding and Joining
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• v.16 no.3
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• pp.148-156
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• 1998

The purpose of this study is to investigate the characteristics of Pb-Free Sn-2%Ag-Bi solder alloys. The solder alloys used in this study is Sn-2%Ag-(3,5,7,9%) Bi It is examined that their properties such as melting range, wettability, microstructure, microhardness, and tensile property. The addition of Bi(3,5,7,9%) lowered the melting point of the solder and the melting range was 196~203$^{\circ}C$. The wettability of the solder as equal to that of Sn-37% Pb solder. The morphology of structure did not change largely by addition of Bi. But the structure of cellular dendrite of linear type displayed. The tensile strength of the solder was superior to that of Sn-37%Pb solder. But the elongation was inferior to that of Sn-37%Pb solder. The hardness of Sn-2%Ag solder was tow times and that of Sn-2%Ag-Bi solder was three times of that in Sn-37%Pb solder. But the effect of increment of Bi content did not change largely.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.30-33
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• 2001

Melting is one of the most effective treatments for stabilizing heavy metals and also creates high value by-products. In this study, authors evaluated the leaching characteristics of heavy metals in melting slag obtained from incinerator ashes. In order to evaluate the environmental compatibility of the recycled melting slag, the samples analysed various leaching tests of heavy metals were raw incinerator ashes, melting slag and the construction materials recycled from melting slag. As the results: (1) The leaching concentrations of tile melting slag were lower than those of the raw incinerator ashes in the experiment performed in accordance with Korea Standard Leaching Test (KSLT). (2) The result of leaching test with the method of RG Min-StB 93. FGSV Forschungsgesellschaft fur Stra $\beta$ en- und Verkehrswesen) met the requirements in German. (3) The compressive strengths of mortar samples used for evaluating the feasibility of recycling the melting slag as construction materials also showed the suitable range for recycling (4) Melting slag was considered the stable materials with respect to the chemical stability against chemical solutions with various pH conditions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.7
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• pp.919-927
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• 1997

The main purpose of this study is to determine bifurcation as the primary instability of a glass melting furnace. Steady-state and unsteady characteristics of natural convection in the partially open cavity as appeared in a glass melting furnace is investigated by using numerical analysis. Three types of convection, such as steady laminar, unsteady periodic or unsteady quasi-periodic convection may occur according to the temperature difference between upper two isothermal surfaces along the depth of cavity in a glass melting furnace. In the temperature difference of 150-900 K between batch and free surface, the larger the temperature difference, the weaker the convection strength and unsteadiness. Since the glass viscosity is increasing exponentially in the lower temperature, the batch freezes the thermofluidic field especially below the surface of it. If the depth of cavity is 0.5 m, the bifurcation to time-dependent natural convection may occur in the range of 60-650 K. If that is 1.0 m, it may occur in the whole range of temperature difference.

• Fashion & Textile Research Journal
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• v.11 no.3
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• pp.474-480
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• 2009

The purpose of this study is to prepare the hardness of polyester(PET) fabric by thermal bonding with low melting component of bicomponent fiber and to describe the change of physical properties of thermal bonded PET fabrics. The PET fabrics were prepared with regular PET fiber as warp and bicomponent fiber as weft. The bicomponent fiber of sheath-core type were composed with a regular PET core and low melting PET sheath. The thermal bonding of PET fabric was carried out in pin tenter from 120 to $195^{\circ}C$ temperature range for 60 seconds. In this study, we investigated the physical properties and melting behavior of PET fiber and the effect of the temperature of the pin tenter on the thermal bonding, mechanical properties. Melting peak of warp showed the thermal behavior of general PET fiber. However, melting peak of weft fiber(bicomponent fiber) showed the double melting peak. The thermal bonding of the PET fabric formed at about temperature of lower melting peak. The optimum thermal bonding conditions for PET fabrics was applied at $190{\sim}195^{\circ}C$ for 60seconds by pin tenter. On the other hand, the tensile strength of the PET fabric decreased with an increasing temperature of thermal bonding.

• Journal of the Korean Ceramic Society
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• v.15 no.2
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• pp.72-78
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• 1978

The vapor pressure of the high melting point oxides, MgO, $Cr_2O_3$, and $MgCr_2O_4$ were measured over the temperature range 1300 to 175$0^{\circ}C$ under vacuum <$10^{-5}$ torr by the Langmuir and the Knudsen method. The Langmuir vapor pressure was increased with elevating temperature and with increasing porosity of the specimen. The difference between the vapor preseures measured by the Langmuir and the Knudsen method was decreased with elevating temperature and the Langmuir vapor pressure finally reached the Knudsen vapor pressure at the melting point when extrapolated. The vapor pressure of other important oxides with high melting points, i.e., $Al_2O_3$, $ThO_2$, $Yb_2O_3$ and $Y_2O_3$ were cited from the references. The Langmuir and the Knudsen vapor pressure of these oxides also showed the same results, i.e., they showed the same value at their melting points.

• KIEAE Journal
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• v.12 no.4
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• pp.97-104
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• 2012

A phase-change material is a substance with a high heat of fusion which, melting and freezing at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid. Therefore, PCMs are classified as latent heat storage (LHS) units. The purpose of this study is to analyze PCM wallboard design parameters using dynamic energy simulation. Among the factors of PCM, melting temperature, latent heat, phase change range, thermal conductivity are very important element to maximize thermal energy storage. In order to analyze these factors, EnergyPlus which is building energy simulation provided by department of energy from the U.S is used. heat balance algorithm of energy simulation is conduction finite difference and enthalpy-temperature function is used for analyzing latent heat of PCM. The results show that in the case of melting temperature, the thermal energy storage could be improved when the melting temperature is equal to indoor surface temperature. It seems that when the phase change range is wide, PCM can store heat at a wide temperature, but the performance of heat storage is languished.

• Journal of Power System Engineering
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• v.10 no.1
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• pp.34-40
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• 2006

The snow melting system by electric heating wires which is adopted in this study is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow accumulated on it. The system is designed to increase traffic safety and capacity. The electric heating wires are buried under paved road at a certain depth and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, and installation place where the system applies. It is tried to figure out that the appropriate range of required heat capacity and installation depth and intervals for solving snowdrifts and freezing problems with the minimum electric power consumption. The most important factors to design the system are calculation of heating capacity depending on weather condition and depth and interval of the electric heating wires depending on air condition respectively. The study were performed under the range of the air temperatures($-2^{\circ}C,\;-5^{\circ}C,\;-8^{\circ}C$), the intervals of the electric heating wires(70mm, 100mm, 125mm), and the installation depths(50mm, 70mm, 100mm). The ready made commercial program package was used to verify the experimental results.