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Pohang, South Korea

Yoon J.-H.,Hanbat National University | Shim S.-R.,Hanbat National University | An Y.S.,Kolon Global Corporation | Lee K.H.,Hanbat National University
Energy and Buildings | Year: 2013

In this study, a mock-up facility equipped with both BIPV windows and normal clear windows was installed to carry out the actual measurement of long-term surface temperature characteristics as the preliminary step for analyzing the impact of the surface temperature rise of thin film BIPV modules on the PV performance. The measurement was carried out for clear double windows and BIPV double windows simultaneously for each inclined angle (0°, 30°, and 90°) for one year, and various statistical analyses were carried out for the collected annual surface temperature data to investigate the surface temperature characteristics of BIPV windows. The analysis result shows that the temperature of windows applied on the vertical plane rises significantly during the winter season, and the temperature of windows applied on the horizontal plane and the inclined plane rises significantly during the summer season with high solar altitude. Regarding indoor surface temperature of windows which is closely related with the thermal comfort of indoor occupants, the surface temperature of BIPV windows with low solar heat gain coefficient was 1 °C lower than that of normal windows during the day time in summer season and was approximately 2 °C higher during the night time in winter season due to the thermal insulation effect. © 2013 Elsevier B.V.

Kim K.-Y.,Gwangju Institute of Science and Technology | Chae K.-J.,Kolon Global Corporation | Choi M.-J.,Gwangju Institute of Science and Technology | Yang E.-T.,Gwangju Institute of Science and Technology | And 2 more authors.
Chemical Engineering Journal | Year: 2013

A new flow-through type microbial fuel cell (MFC) system was developed for practical application as a wastewater treatment process. The ultrafiltration MFC (UF-MFC), which has a UF membrane instead of an expensive cation exchange membrane (CEM) as a separator, was designed to continuously filter the anode chamber solution to cathode chamber via UF membrane. Through the UF-MFC system, high-quality effluent and electricity generation can be simultaneously achieved by the two different wastewater treatment processes applied, e.g., a biological organic pollutant removal in the anode chamber by electrochemically active bacteria and a physical filtration by UF membrane. The maximum power density of the UF-MFC was 53.5mW/m2, lower than the power density shown by comparison with a Nafion based two-chambered MFC (55.7mW/m2). However, the UF-MFC continuously produced high-quality effluent that did not need further post-treatment processes, showing a high and stable COD removal efficiency (>90%), and high rejection rate for total coliform (>97%) and suspended solids during 20d operation. This study confirmed that UF-MFC s could be a promising technology for both of efficient wastewater treatment and energy recovery from wastewater in future wastewater treatment plants. © 2012 Elsevier B.V.

Tran N.T.,Sejong University | Tran T.K.,Ho Chi Minh City University of Technology and Education | Jeon J.K.,Kolon Global Corporation | Park J.K.,Sejong University | Kim D.J.,Sejong University
Cement and Concrete Research | Year: 2016

The fracture energy of ultra-high-performance fiber-reinforced concrete (UHPFRC) at high strain rates (5-92 s-1) was investigated, and specimens with 1-1.5% fibers exhibited very high fracture energy (28-71 kJ/m2). Evaluation of the rate effects on the UHPFRC fracture resistance, including fracture strength (ft), specific work-of-fracture (WS), and softening fracture energy (WF), indicated that ft and WS were highly sensitive to strain rate, whereas WF was not. The effects of fiber type, volume content, specimen shape and fiber blending on the fracture resistance at high and static strain rates differed significantly: 1) smooth fibers exhibited higher ft and WS at high rates than twisted fibers; 2) higher fiber volume content did not clearly generate higher WS and WF at high rates; 3) notched specimens generally exhibited higher fracture resistance than un-notched samples at both static and high rates; and 4) UHPFRC blending two fibers produced higher WS and WF than UHPFRC with mono fiber at high rates. © 2015 Elsevier Ltd.

Lee K.-I.,Ajou University | Yeom D.,Ajou University | Kim E.-J.,Kolon Global Corporation
Journal of Asian Architecture and Building Engineering | Year: 2013

As quality of life has become a center of attention internationally, studies on comfortable indoor environments have been actively conducted. Particularly, the number of patients suffering from indoor air quality related diseases such as atopic dermatitis and new house syndrome have increased and the average time spent indoors these days is more than half a day, so counter solutions have been attempted in the field of architecture, such as using eco-friendly and ecological materials. With this background, this research aimed to verify the effect of rice hull insulation on the indoor environment, which is widely used in rural areas. To do this, two real-scale mock-ups with rice hull insulation and polystyrene insulated panels, which is the construction generally used in rural areas, were constructed and analyzed, and the effect of rice hull insulation on an indoor environment was verified.

Chae K.-J.,Korea Maritime and Ocean University | Kim I.-S.,Korea Maritime and Ocean University | Ren X.,Beijing University of Civil Engineering and Architecture | Cheon K.-H.,Kolon Global Corporation
Energy Conversion and Management | Year: 2015

A micro-hydropower (MHP) system with a flow-variable turbine was tested for over one year to investigate its applicability for small-scale municipal wastewater treatment plants (WWTP) with severe flow fluctuations. The applied MHP was designed as a semi-Kaplan, equipped with only adjustable turbine blades without guide vanes, hence it is simple in its mechanical structure and is inexpensive while providing high-level performance. To exploit as much hydro-energy as possible, a maximum water level tracking control scheme in the forebay tank was employed and the turbine blade angle was accurately adjusted corresponding to the oncoming flow rate, which allows water to hit the blade in the best direction for maximum efficiency. Despite its micro-scale (12.3 kW at design conditions of 4.30 m net head and 0.35 m3/s flow rate), the applied MHP can work stably over a wide range of flows from 57% to 123% of the rated design flow, with the highest turbine efficiency of 91.3% and its corresponding overall electric efficiency of 80.3%. Even as the flow rate decreases to 23% of the design flow, the turbine still runs but at relatively lower efficiencies. Because of wide flow adjustability, the tested MHP can generate power even at extreme flow rates so that an almost complete amount (95.8%) of WWTP's total effluent was used to produce 68.1 MW h annually. In addition, as compared with similar WWTP-based hydropower systems in South Korea, the tested MHP achieved 1.78-2.80 times higher normalized electricity in both flow rate and net head, indicating a more efficient use of the flow and head. These results should draw new interest in the WWTP-based MHP, which was considered unfeasible in the past in Korea due to its low efficiency. © 2015 Elsevier Ltd. All rights reserved.

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