• Solar Energy
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• v.12 no.3
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• pp.28-36
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• 1992

The performance of a latent heat storage system using a thermosyphon as the heat transfer device between the heat source and the phase change material was investigated experimentally. In order to increase the effective conductivity of the phase change material, layers of copper wire mesh were immersed in the paraffin wax(Sunoco P-116) in such a way that they also may be considered as fins of the thermosyphon. The important results are as follows : (1) The void space of the wire mesh allowed the convection to occur, thus enhanced the performance of the system : (2) The increase of the number of layer of wire mesh increased the conduction heat transfer. However, it also had adverse effect of subduing convective motion of liquid wax : and (3) Overall heat transfer coefficient and thermosyphon conductance increased with the increase of the number of layer of wire mesh, whereas the heat transfer coefficient between the thermosyphon and the wax decreased.

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.121-129
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• 2000

The thermal performance of a flat evaporator for capillary pumped loop (CPL) applications was investigated. Two to four layers of coarse wire screen wicks were placed onto the heated surface to provide irregular passages for vapor flow. The evaporator and condenser were separated by a distance of 1.2 m and connected by individual liquid and vapor lines. The wall material was copper and the working fluid was ethanol. The experimental facility utilized a combination of capillary and gravitational forces for liquid return, and distribution over the evaporator surface. The tubing used for vapor and liquid lines was 9.35 mm or less in diameter and heat was removed from the condenser by convection of air. A heat flux of up to $4.9{\times}10^4$ $W/m^2$ was applied to a flat evaporator having dimensions of 100 mm by 200 mm, 20 mm thick. The thermal resistance of the system as well as the temperature characteristics of the system was investigated as the evaporator heat flux and the condenser cooling capacity varied. The performance of the evaporator and effect of condenser cooling capacity were analyzed and discussed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.148-148
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• 2016

디스플레이 시장이 rigid에서 flexible로 변화하기 시작하면서 유연 투명전극 소재에 대한 수요가 증가하고 있다. 투명전극으로 대표되는 Indium Tin Oxide(ITO)는 고투과 저저항의 장점을 가지지만 유연성이 떨어져 이를 대체 할 투명전극 소재로 Metal mesh, Ag nano-wire, CNT, Graphene, Conductive polymer 등에 대한 응용 연구가 활발히 진행되고 있다. 본 연구에서는 Metal mesh 용 Cu thin film 형성을 위해 플라즈마 표면처리 기술로 플라스틱 기판과 Cu 박막 사이의 밀착력을 향상시키고자 공정 연구를 수행하였다. 고품질의 Cu thin film 제작을 위해 양산용 roll to roll 장비를 이용하였고, 선형이온소스를 적용하여 플라즈마 표면처리를 수행하였다. 이후 마그네트론 스퍼터링을 통해 Ni buffer layer 및 Cu 박막 증착 공정을 in-situ로 진행하였다. 이러한 공정을 통해 제작한 Cu thin film의 밀착력을 평가하기 위해 cross cut test(ASTM D3359)를 수행하였다. 그 결과 플라스틱 기판과 Cu 금속 박막 사이의 밀착력이 0B에서 5B까지 향상된 것을 확인하였고, 플라즈마 표면처리 공정을 통해서 저항 또한 감소되는 결과를 얻을 수 있었다. 본 연구를 통해 polyethylene terephthalate(PET)뿐만 아니라 polyimide(PI) 기판 상에서도 플라즈마 표면처리를 통해 금속 박막의 밀착력이 향상되는 결과를 확인하였으며, flexible copper clad laminate (FCCL) 같은 유연 정보 소자 분야에 응용 가능할 것으로 기대된다.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.259-265
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• 1982

We have designed a new type of bubble oxygenator (KOREA-KIM VENOTHERM OXYGENATOR) made of PVC sheet and deforming mesh incorporated in the heat exchanger, and evaluated in experimental animal for the analysis of it`s efficiency. The Oxygenator has low priming volume with high flow rate up to 6 L/rain, and efficiency of heat exchanger was excellent as 1-$1.5^{\circ}C.$ using total cardiopulmonary bypass method under moderate to deep hypothermia. Average priming volume of 1317 ml with 30% hemodilution method was perfused with an average of 1.1-3.0 L/min.$M^2$of arterial blood and pure oxygen at a rate of 2-3.4 L/min for 49.6 minutes continuously in average. During total cardiopulmonary bypass, average $PaO_2$ was $159.8{\pm}60$mmHg, $PaCO_2$ $41.0{\pm}3$mmHg respectively under $SaO_2$ over 96% with systolic arterial pressure of 70 mmHg and CVP of 5-10 cm$H_2O$. Plasma free Hemoglobin was $7.0{\pm}4$ mg/dl with 25% drop of hemoglobin and hematocrit at the end of cardiopulmonary bypass. This KKV Oxygenator was observed to have excellent capabillty of oxygen and carbon dioxide gas transfer with small amount of blood trauma, and the efficiency of heat exchanger was satisfactory during cooling and rewarming of the bubbled blood. Disadvantages have included the somewhat poor deforming effect due to loose PVC fiber mesh, the extracompact character of Teflon filters, and the rough inner surface of the heat exchanger copper pipes.

• Journal of Mechanical Science and Technology
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• v.19 no.4
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• pp.1036-1043
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• 2005

Concentric annular heat pipes (CAHP) were fabricated and tested to investigate their thermal characteristics. The CAHPs were 25.4 mm in outer diameter and 200 mm in length. The inner surface of the heat pipes was covered with screen mesh wicks and they were connected by four bridge wicks to provide liquid return path. Three different heat pipes were fabricated to observe the effect of change in diameter ratios between 2.31 and 4.23 while using the same outer tube dimensions. The major concern of this study was the transient response as well as isothermal characteristics of the heat pipe outer surface, considering the application as uniform heating device. A better performance was achieved as the diameter ratio increased. For the thermal load of 180 W, the maximum temperature difference on the outer surface in the axial direction of CAHP was $2.3^{\circ}C$ while that of the copper block of the same outer dimension was $5.9^{\circ}C.$ The minimum thermal resistance of the CAHP was measured to be $0.004^{\circ}C/W.$ In regard to the transient response during start-up, the heat pipe showed almost no time lag to the heat source, while the copper block of the same outer dimensions exhibited about 25 min time lag.

• Resources Recycling
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• v.25 no.1
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• pp.3-9
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• 2016

The leaching behavior of gold from waste CPU chip using Iodide/Iodine solution was studied. The direct leaching of gold with Iodide/Iodine solution for CPU chip under the size of 150 mesh showed leaching ratio of 20%. It was assumed that the copper film was produced on the gold particle during grinding process and the copper film prevents lodine/Iodide solution from contacting with leachable gold. Meanwhile, the extraction of gold was improved to 90% by pretreatment process with $HNO_3$ solution. In order to explain the result, EDS and ICP analysis for the leaching residue were conducted. It was found that the copper coated on the surface of the gold particle was removed about 80% by $HNO_3$, resulting in the increment of gold leaching rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.530-536
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• 2021

This paper presents the performance measurement results of a hybrid sheet with both shielding and heat dissipation functions developed by laminating copper mesh sheets and natural graphite sheets, which are used widely as electromagnetic shielding and heat-dissipating materials in electronic devices, without a pressure-sensitive adhesive (PSA). The results were compared by measuring the vertical and horizontal thermal conductivity with two other products to confirm the heat dissipation performance. A radiation emission test confirmed the electromagnetic shielding performance using a 3m electromagnetic anechoic chamber according to the CISPR 11 standard. In the case of vertical thermal conductivity, the proposed hybrid sheet was approximately 8.63 times higher than that of an aluminum sheet with heat dissipation coating and 18.7 times higher than that of a copper sheet laminated with artificial graphite with PSA. The proposed hybrid sheet was approximately 0.64 times that of the sheet, and approximately 1.76 times that of the heat-dissipated aluminum sheet in case of horizontal thermal conductivity. Measurements after applying each sheet in the same heat source revealed the proposed hybrid sheet to have the best heat dissipation performance. The radiation emission test showed that significantly radiation noise had been removed.

• Resources Recycling
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• v.28 no.2
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• pp.31-39
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• 2019

The pelletizing of printed circuit board (PCB) sludge was researched for copper recovery in pyrometallurgical process. This pelletizing was carried out by using self-manufactured compression-type apparatus after pre-treatments (drying, water scrubbing, size classification) were proceeded. The physical properties (compression strength and drop-breakage test) were tested with a change of sludge sizing and the number of compression. In the case of using the undersized sludge of #140, its properties were improved to 0.6 MPa and 9.3 times. Moreover, they increased to 0.82 MPa and 19.0 times by using the #140 ~ 325 sludge. These imply that the packing density increases due to the elimination of large-sized sludge (#140), and also the weight of required binder decreases by the removal of fine-sized sludge (#325).

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2124-2129
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• 2007

A VCHP was fabricated and tested for its thermal performance. The container was made of copper, and the working fluid was water. STS-316 screen of mesh number 100 was inserted as a capillary structure. As a baseline performance, a normal heat pipe of the same dimensions was tested in advance to compare with VCHP, where an inert gas container was attached. The outer diameter of the heat pipe was 12.8 mm and the total length was 600 mm. The evaporator and the condenser lengths were both 200 mm. The thermal load ranged from 20 to 300W. Typical result revealed that the operating temperature of the VCHP stayed almost constant, while that of the normal heat pipe varied as much as 40$^{\circ}C$. Therefore, it was demonstrated that the VCHP is very effective for temperature control of heat-dissipating devices.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.572-578
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• 2001

This study is to research the heat transfer characteristics in copper-water heat pipes with screen wick, #100. Recently, the semiconductor capacity of an electronic unit has been larger, on the contrary, its size is smaller than before. As a result, a high-performance cooling system is needed. Experimental variables are inclination angle and temperature of cooling water. The distilled water was used for the working fluid. At a inclination angle ${-6}^{\circ}$, #100 2layer screen mesh is shown the best heat transfer performance.