• Journal of Hydrogen and New Energy
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• v.28 no.2
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• pp.156-165
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• 2017

This study quantitatively assessed the environmental impacts of fuel cell (FC) systems by performing life cycle assessment (LCA) and analyzed their energy efficiencies based on energy return on investment (EROI) and electrical energy stored on investment (ESOI). Molten carbonate fuel cell (MCFC) system and polymer electrolyte membrane fuel cell (PEMFC) system were selected as the fuel cell systems. Five different paths to produce hydrogen ($H_2$) as fuel such as natural gas steam reforming (NGSR), centralized naptha SR (NSR(C)), NSR station (NSR(S)), liquified petroleum gas SR (LPGSR), water electrolysis (WE) were each applied to the FCs. The environmental impacts and the energy efficiencies of the FCs were compared with rechargeable batteries such as $LiFePO_4$ (LFP) and Nickel-metal hydride (Ni-MH). The LCA results show that MCFC_NSR(C) and PEMFC_NSR(C) have the lowest global warming potential (GWP) with 6.23E-02 kg $CO_2$ eq./MJ electricity and 6.84E-02 kg $CO_2$ eq./MJ electricity, respectively. For the impact category of abiotic resource depletion potential (ADP), MCFC_NGSR(S) and PEMFC_NGSR(S) show the lowest impacts of 7.42E-01 g Sb eq./MJ electricity and 7.19E-01 g Sb eq./MJ electricity, respectively. And, the energy efficiencies of the FCs are higher than those of the rechargeable batteries except for the case of hydrogen produced by WE.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.23-24
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• 2006

We have synthesized electroluminescence materials. including [2-(2-hydroxyphenyl)benzoxazole] (Zn(HPB)$_2$), [(2-(2-hydroxyphenyl)benzoxazole)(8-hydoxyquinoline)] (Zn(HPB)q) and [(1, 10-phenanthroline)(8-hydroxyquinoline)] Zn(phen)q. The ionization potential (IP) and electron affinity (EA) of each Zn-complex was measured using cyclic-voltammetry (C-V). Basing on the consideration of matched in the energy levels of the materials. We investigated the electron transporting properties of Zn(HPB)q and Zn(phen)q compared with $Alq_3$, and also we investigated the hole blocking properties of Zn(HPB)$_2$, compared with BCP. As a result, we used Zn-complex to enhance the performance of OLED. Therefore, we demonstrate that Zn(HPB)q and Zn(phen)q are useful as an electron transporting material. Zn(HPB)$_2$ is also good a hole blocking material.

• New & Renewable Energy
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• v.4 no.3
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• pp.5-14
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• 2008

The target for the reduction of $CO_2$ emissions, as specified in the Kyoto Protocol, can only be achieved by an extended use of renewable fuels and the increasing of the energy efficiency. The energy generation from waste gases with a reasonable content of methane like biogas can significantly contribute to reach this target. A further reduction of greenhouse gas emissions is possible by increasing the electrical efficiency using progressive technologies. Fuel cells can be highly energy conversion devices. Utilizing biogas as the fuel for fuel cell systems offers an option that is technically feasible, potentially economically attractive and greenhouse gas neutral. High temperature fuel cells that are able to operate with carbon monoxide in the feed are well suited to these applications. Furthermore, because they do not require noble metal catalysts, the cost of high-temperature fuel cells has the greatest potential to become competitive in the near future compared to other types of fuel cells.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.27-29
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• 1994

Recently, the energy situation in Korea has been significantly changed. Rapid increase in electricity demand, tremendous financial need for new power plant construction, and environmental problem have led to search for more efficient energy production and energy conservation technologies. Due to the potential energy and cost savings to both electric utilities and industries, cogeneration will play an important role in the electric power and thermal energy supply in the future. In this study, we present the COGENMASTER computer model for optimal system configuration and economic analysis of cogeneration system. We also present several case studies with this module to analyze Korean cogeneration market. The result of this study will be useful to utility and industrial cogeneration planners for rapid analysis of cogeneration's value under a broad range of scenarios.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.37-44
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• 2022

Plug-in Hybrid electric vehicles (PHEV) show great potential to reduce gas emission, improve fuel efficiency and offer more driving range flexibility. Moreover, PHEV help to preserve the eco-system, climate changes and reduce the high demand for fossil fuels. To address this; some basic components and energy resources have been used, such as batteries and proton exchange membrane (PEM) fuel cells (FCs). However, the FC remains unsatisfactory in terms of power density and response. In light of the above, an electric storage system (ESS) seems to be a promising solution to resolve this issue, especially when it comes to the transient phase. In addition to the FC, a storage system made-up of an ultra-battery UB is proposed within this paper. The association of the FC and the UB lead to the so-called Fuel Cell Battery Electric Vehicle (FCBEV). The energy consumption model of a FCBEV has been built considering the power losses of the fuel cell, electric motor, the state of charge (SOC) of the battery, and brakes. To do so, the implementing a reinforcement-learning energy management strategy (EMS) has been carried out and the fuel cell efficiency has been optimized while minimizing the hydrogen fuel consummation per 100km. Within this paper the adopted approach over numerous driving cycles of the FCBEV has shown promising results.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.157-159
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• 1993

Recently, in the industrial applications, accurate arc control for welding machine are developed. This paper describes arc control of inverter-fed arc welding machine, and efficiency of inverter-fed arc welding machine. It is shown that the arc pressure and are stiffness of the pulse arc nay be as much as several times that of the equivalent dc are. Finally, the theoretical predictions are compared with test. The potential of such a welding machine is also described.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.309-310
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• 2007

Spacecrafts such as most of commercial satellites that are operating in the geostationary orbit can be subjected to intense irradiation by charged particles. The surface made of dielectric materials can therefore become probable sites for damaging electrostatic discharges. Thanks to a specially equipped chamber, the spatial environment can be reproduced experimentally in the laboratory. In this paper, the behavior of high energy electrons injected in polymers such as PolyMethylMetaAcrylate (PMMA) and Kapton is studied. Results obtained by surface potential technique, pulse-electro acoustic device and a cell based on the split Faraday cup system are analyzed and discussed.

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.205-211
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• 2010

Effects of operating parameters on electrical properties and ozone generation of Plasma Gun for ballast water treatment were investigated in a laboratory scale experiment. Electrical discharges and ozone generation initiated with applying voltages higher than discharge onset value. Ozone concentration was almost linearly increased with the increase of applied voltage. The optimum electrode gap distance which gave the optimum energy efficiency of ozone generation was 1.95 mm in the experimented apparatus. The effect of inner electrode material on the electrical energy transfer was negligible, however, the difference of electrical and thermal conductivities between electrode materials significantly influenced the ozone generation. In a constant geometrical structure, the electrical energy density played an important role in the ozone generation. The increase of oxygen content in the feeding gas enhanced the ozone generation by lowering ionization potential and promoting ozone source.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.87-106
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• 2024

Vehicle-to-Home (V2H) and Home Centralized Photovoltaic (HCPV) systems can address various energy storage issues and enhance demand response programs. Renewable energy, such as solar energy and wind turbines, address the energy gap. However, no energy management system is currently available to regulate the uncertainty of renewable energy sources, electric vehicles, and appliance consumption within a smart microgrid. Therefore, this study investigated the impact of solar photovoltaic (PV) panels, electric vehicles, and Micro-Grid (MG) storage on maximum solar radiation hours. Several Deep Learning (DL) algorithms were applied to account for the uncertainty. Moreover, a Reinforcement Learning HCPV (RL-HCPV) algorithm was created for efficient real-time energy scheduling decisions. The proposed algorithm managed the energy demand between PV solar energy generation and vehicle energy storage. RL-HCPV was modeled according to several constraints to meet household electricity demands in sunny and cloudy weather. Simulations demonstrated how the proposed RL-HCPV system could efficiently handle the demand response and how V2H can help to smooth the appliance load profile and reduce power consumption costs with sustainable power generation. The results demonstrated the advantages of utilizing RL and V2H as potential storage technology for smart buildings.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.331-334
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• 2000

The organic electroluminescent(EL) device has gathered much interest because of its large potential in materials and simple device fabrication. We fabricated EL devices which have a blended single emitting layer containg poly(Nvinylcarbazole)[PVK] and poly(3-dodecylthiophene)[P3DoDT]. The molar ratio between P3DoDT and PVK changed with 1:0, 2:1 and 1:1. To improve the external quantum efficiency of EL devices, we applied insulating layer, LiF layer between polymer emitting layer and AI electrode. All of the devices emit orange-red light and it's can be explained that the energy transfer occurs from PVK to P3DoDT. Within the molar ratio 1:0, 2:1 and 1:1, the energy transfer was not saturated, which results in the not appearance of PVK emission in the blue region. In the voltage-current and voltage-light power characteristics of devices applied LiF layer, current and light power drastically increased with increasing with applied voltage. In the consequence of the result, the light power of the device have a molar ratio 1:1 with LiF layer was about 10 times larger than that of the device without PVK at 6V.