• 한국도로학회논문집
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• 제3권4호
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• pp.105-116
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• 2001

본 연구는 주물고사를 이용한 아스팔트 콘크리트와 주물고사의 물리적 화학적 특성을 비교 분석하는 것이다. 주물고사의 아스팔트 콘크리트 적용성을 평가하기 위하여 XRF, SEM, 제타전위를 측정하여 주물고사의 물리 화학적 특성을 알아보았다. 주물고사 아스팔트 콘크리트의 박리저항성을 향상시키기 위하여 박리방지제(소석회(Hydrated lime), 액상박리방지제)를 사용하였다. 그리고 주물고사 아스팔트 콘크리트 혼합물의 인장특성과 내구성 향상을 위하여 LDPE를 사용하였다. 또한 주물고사 아스팔트 콘크리트의 공용성을 알아보기 위하여 간접인장강도, 수분취약성시험, 동결 융해시험, 반복주행시험을 수행하였다. 시험결과 주물고사 아스팔트 콘크리트의 역학적 특성이 일반 아스팔트 콘크리트에 비해 같거나 향상되는 것으로 나타났다. 따라서 주물고사를 아스팔트 콘크리트에 재활용할 수 있다는 결론을 얻었다.

• 자원리싸이클링
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• 제19권1호
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• pp.57-65
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• 2010

최근, 인쇄회로기판 제조공정으로부터 유가자원을 회수하고자 하는 연구가 활발히 진행되고 있다. 인쇄회로기판의 드릴가공 받침대로 사용한 후 폐기되는 백보드 소재활용과 소형화, 고 신뢰성화에 따른 유가금속인 금 회수가 필수적이다. 특히 이동통신용 전자부품의 핵심소재로 사용되는 인쇄회로기판부품에는 최소 0.03 ${\mu}m$에서부터 최대 50 ${\mu}m$ 두께로 금이 도금되어 있다. 금, 원자재, 약품 값 폭등으로 생산현장의 유가자원 활용이 중요한 과제로 대두되면서 유가자원 활용을 위한 경쟁이 가속화되는 추세다. 본고에서는 인쇄회로기판 제조공정에서 발생하는 폐백보드 및 금의 회수에 대한 기술동향을 제공함으로써 유가자원 활용 산업발전에 기여하고자 하였다.

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.454-458
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• 2017

$Bi_2Te_3$-based alloys have been intensively investigated as active materials for thermoelectric power generation devices from low-temperature (< $250^{\circ}C$) waste heat. In the present study, we fabricated Pb-doped, p-type $Bi_{0.48}Sb_{1.52}Te_3$ polycrystalline bulks by using meltsolidification and spark plasma sintering techniques, and evaluated their thermoelectric transport properties in an effort to develop optimized composition for low-temperature power generation applications. The electronic and thermal transport properties of $Bi_{0.48}Sb_{1.52}Te_3$ could be manipulated by Pb doping. As a result, the temperature for a peak thermoelectric performance (zT) gradually shifted toward higher temperatures with Pb content, suggesting that thermoelectric power generation efficiency can be enhanced by controlled Pb doping.

• 자원리싸이클링
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• 제26권4호
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• pp.9-18
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• 2017

최근 전자산업의 급격한 성장으로 전자부품스크랩의 발생량 역시 빠르게 증가하고 있다. 특히 전자부품스크랩의 구성부품 중 인쇄회로기판(PCB)은 금, 은, 구리, 주석 및 니켈 등 일반금속부터 귀금속 및 희소금속까지 포함하고 있는 중요한 재활용 대상이다. 하지만 국내에는 일부 대기업을 중심으로 한 PCB 처리 및 재활용 기술이 상용화되어 있으며 그 외 처리량에 대해서는 정확하게 집계되지 않고 있는 실정이다. 이에 따라 몇몇 도시광산 업체 및 연구소, 대학교를 중심으로 기존 대기업 중심의 상용화 공정 외에 PCB로부터 유가금속을 회수하고 원료로 재사용하는 연구가 진행되고 있다. 따라서 본 연구에서는 국내의 폐 PCB의 처리 및 회수현황과 재활용 기술 동향을 분석하였고, 이를 통해 PCB 폐자원의 자원순환 활성화에 기여하고자 하였다.

• International Journal of Air-Conditioning and Refrigeration
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• 제12권1호
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• pp.1-9
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• 2004

The purpose of the present study is to examine the heat transport limitations in a screen mesh heat pipe for electronic cooling by theoretical analysis. Diameter of pipe was 6mm, and mesh numbers were 50, 100, 150, 200 and 250, and water was investigated as working fluid. According to the change of mesh number, wick layer, inclination and saturation temperature, the maximum heat transport limitations by capillary, entraintment, sonic and boiling were analyzed by a theoretical design method of heat pipe, including capillary pressure, pumping pressure, liquid friction coefficient in wick, vapor friction coefficient, etc. Based on the results, the capillary limitation in a small diameter of heat pipe is largely affected by mesh number and wick layer. Mesh number of 250 is desirable not to be used in pipe diameter of 6 mm, because capillary heat transport limitation decreases by the abrupt increase of liquid friction pressure due to the small liquid flow area. For the heat transport of 15 watt in 6mm diameter pipe, mesh number of 100 and one layer is an optimum wick condition, which thermal resistance is the smallest.

• International Journal of Air-Conditioning and Refrigeration
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• 제12권1호
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• pp.21-29
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• 2004

This paper is to study the heat transfer performance of the copper-water heat pipe with screen wicks. Recently, the semiconductor capacity of an electronic unit becomes larger, but its size becomes much smaller. As a result, a high- performance cooling system is needed. Experimental variables are inclination angles, temperatures of cooling waters and the mesh number of screen wicks. The distilled water was used as a working fluid. Based on the experimental results, when the copper-water heat pipe of 6mm diameter is used at the top heat mode, the heat transfer performance of 100 mesh 2 layers heat pipe is better than that of 150 and 200 mesh. The thermal resistance of the two layers with the 100-mesh screen was 0.7-$0.8^{\circ}C$/W.

• ETRI Journal
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• 제38권4호
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• pp.787-797
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• 2016

Mining, construction, and other special vehicles for heavy use are designed to work under high-performance and off-road working conditions. The driving and executive mechanisms of the support structures and superstructures of these vehicles frequently operate under high loads. Such high loads place the equipment under constant risk of an accident and can jeopardize the dynamic stability of the machinery. An experimental investigation was conducted on a refuse collection vehicle. The aim of this research was to determine the working conditions of a real vehicle: the kinematics of the waste container, that is, a hydraulic rotate drum for waste collection; the dynamics of the load manipulator (superstructure); the vibrations of the vehicle mass; and the strain (stress) of the elements responsible for the supporting structure. For an examination of the force (weight) on the rear axle of a heavy vehicle, caused by its own weight and additional load, a universal measurement system is proposed. As a result of this investigation, we propose an alternative system for continuous vehicle weighing during waste collection while in motion, that is, an on-board weighing system, and provide suggestions for measuring equipment designs.

• 한국염색가공학회지
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• 제17권4호
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• pp.21-26
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• 2005

A combination separation system is composed of three parts, simple microfiltration unit for the pretreatment of real waste IPA, pervaporation unit with plate and frame type module(the effective membrane area 9,040$cm^2$), and simple ultrafiltration unit as a refiner. Utrafiltration module with hollow fiber membrane(MWCO 10,000) used to purify waste aqueous IPA solution. In addition, the flux of $CMPA-K^+$ composite membrane for waste aqueous IPA solution was very steady-state with long experiment time(30 days). And the standard deviation($\sigma$) was 0.152 and then the coefficient of variation($CV\%$)was 10.82 The IPA concentration on the membrane performance using pervaporation module system could be increased from $89.85wt(\%)$ to more than $99.90wt\%$ in about 8hr at operation temperature of $70^{\circ}C$ using the pervaporation module system. Therefore, a combination separation process system of simple filtration and pervaporation was very effective for the purpose of the IPA purification and reuse front industrial electronic components cleaning process.

• 산업기술연구
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• 제31권A호
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• pp.53-57
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• 2011

Recently due to dramatically increasing demand of liquid crystal display (LCD) panel in IT industry, the used LCD panel glass has been wasted from electronic items, and also panel glass of poor quality during manufacturing process. The wasted LCD panel glass was crushed in the range of 0.42 to 2mm and evaluated for its usefulness as a aggregate in production of cement concrete brick. Cement concrete specimens with various mixing ratios of weathered granite soil, LCD panel glass and cement were cured in wetness for 7 days at $40^{\circ}C$ and then tested for uniaxial comprehensive strength (UCS)(KS F 4004 method). Specimen with a mixing ratio, 1:6:3, of weathered granite, LCD panel glass and cement, respectively, showed the highest average in the UCS test($26.51N/mm^2$). It is much higher than that of commercial brick without glass($17.00N/mm^2$). Conclusively waste LCD panel glass can be reutilized economically as a raw building material of good quality.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.944-949
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• 2018

The mass attenuation coefficients (${\mu}/{\rho}$) of food waste samples (pomegranate peel, acorn cap, lemon peel, mandarin peel, pumpkin peel, grape peel, orange peel, pineapple peel, acorn peel and grape stalk) have been measured employing a Si(Li) detector at 13.92, 17.75, 20.78, 26.34 and 59.54 keV. Also, the theoretical values of the mass attenuation coefficients have been evaluated utilizing mixture rule from WinXCOM program. The results showed that the lemon peel has the highest values of ${\mu}/{\rho}$ among the selected samples. From the obtained mass attenuation coefficients, we determined some absorption parameters such as effective atomic number ($Z_{eff}$), electron density ($N_E$) and molar extinction coefficient (${\varepsilon}$). It was found that the $Z_{eff}$ values of all food wastes lie within the range of 4.034-7.595, whereas the $N_E$ of the studied food wastes was found to be in the range of $0.301-1.720{\times}10^{25}$ (electrons/g) for present energy region.