• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.319-324
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• 2014

The wafer carrier is made of PP, PC, PE resin which have excellent heat and chemical resistance and electrical properties. However, particle generation has become a problem due to static electricity generated in the carrier. Some conductive material such as carbon black (CB) and carbon fiber (CF) are added for the purpose of anti-static, however, additional for motility and particle contamination problems due to high carbon content occurs. In this paper, the electrical characteristics and workability are observed and compared by adding low Carbon Nono Tube(CNT) to each PP, PC and PE resin to solve the problem.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.495-498
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• 2001

The distribution line through which electricity is supplied from substation to customer generally varies by underground line and overhead line. In contrast that the underground line is shielded, the overhead lines do not have the shield layer. To overcome this weak point of the overhead lines, the aerial bundled cable(ABC) connection systems have been developed. The basic concept of the ABC connection system is the application of the underground cable system containing complete shield layer to the overhead cable system. The ABC system is the innovative technologies which enable the prevention of electric shocks, reduction of the maintenance charge and damage of the cable. This paper give a full detail of vertical connection system applied within a country.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.31-34
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• 2007

Fuel cell with high electric efficiency has many probabilities of commercial use. Especially, polymer electrolyte or proton exchange membrane fuel cell (PEMFC) which is a low operating temperature and has less influence on $CO_2$ concentration is considered the power generation system of small building and household. We calculated the optimal operational plans of 1 kW household PEMFC power system based on daily electric and heat demand patterns of various size of apartments. Calculated results show that the economic feasibility of PEMFC power system is very sensitive to the cost policy of electricity and natural gas.

• Membrane Journal
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• v.29 no.6
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• pp.323-328
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• 2019

It is a highly important problem for mankind to supply sufficient energy, which has been connected to production and supply of electricity. In terms of the problems, this study fabricated a new sort of solid polymer electrolyte membrane for supercapacitors. The fabricated electrolyte employed grafting poly(oxyethylene methacrylate) (POEM) side chain on poly(vinyl alcohol) (PVA) main chain by free-radical polymerization. It is the first time to utilize PVA-g-POEM graft copolymer as an electrolyte membrane for supercapacitor. The chain behavior of PVA was transformed by grafting POEM side chains, which was analyzed by FT-IR spectra. Also, the capacitance performances of fabricated supercapacitors were explored by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and ragone plot. We suggest a new point, the grafting of the electrolyte of supercapacitor in this study.

• Polymer(Korea)
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• v.39 no.2
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• pp.353-358
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• 2015

Aqueous-based, environmentally friendly photocurrent generation has been highlighted to produce electricity by mimicking photosynthesis in nature. We fabricated a photocurrent generation system using a conjugated oligoelectrolyte (COE) assembled in lipid vesicles and a fluorescence dye, and investigated the fluorescence resonance energy transfer (FRET) between two species and the influence of FRET on the photocurrent generation. The FRET efficiency from the electron donor, COE, to the electron acceptor, the dye, increased with the dye concentrations, but the photocurrent increased and then decreased with the dye concentrations. We discussed about the role of FRET and electron shuttles over the variation of photocurrent.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.297.2-297.2
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• 2013

Scavenging electricity from wasteful energy resources is currently an important issue and piezoelectric nanogenerators (NGs) based on zinc oxide (ZnO) are promising energy harvesters that can be adapted to various portable, wearable, self-powered electronic devices. Although ZnO has several advantages for NGs, the piezoelectric semiconductor material ZnO generate an intrinsic piezoelectric potential of a few volts as a result of its mechanical deformation. As grown, ZnO is usually n-type, a property that was historically ascribed to native defects. Oxygen vacancies (Vo) that work as donors exist in ZnO thin film and usually screen some parts of the piezoelectric potential. Consequently, the ZnO NGs' piezoelectric power cannot reach to its theoretical value, and thus decreasing the effect from Vo is essential. In the present study, c-axis oriented insulator-like sputtered ZnO thin films were grown in various temperatures to fabricate an optimized nanogenerator (NGs). The purity and crystalinity of ZnO were investigated with photoluminescence (PL). Moreover, by introducing a p-type polymer usually used in organic solar cell, it was discussed how piezoelectric passivation effect works in ZnO thin films having different types of defects. Prepared ZnO thin films have both Zn vacancies (accepter like) and oxygen vacancies (donor like). It generates output voltage 20 time lager than n-type dominant semiconducting ZnO thin film without p-type polymer conjugating. The enhancement is due to the internal accepter like point defects, zinc vacancies (VZn). When the more VZn concentration increases, the more chances to prevent piezoelectric potential screening effects are occurred, consequently, the output voltage is enhanced. Moreover, by passivating remained effective oxygen vacancies by p-type polymers, we demonstrated further power enhancement.

• Membrane Journal
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• v.32 no.5
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• pp.336-347
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• 2022

Reverse electrodialysis (RED) is one of the promising eco-friendly renewable energy technologies which can generate electricity from the concentration difference between seawater and freshwater by using ion-exchange membranes as a diaphragm. The ion-exchange membrane is a key component that determines the performance of RED, and must satisfy requirements such as low electrical resistance, high permselectivity, excellent durability, and low manufacturing cost. In this study, pore-filled anion-exchange membranes were fabricated using porous polymer substrates having various thicknesses and porosity, and the effects of ion-exchange polymer composition and membrane thickness on the power generation performance of RED were investigated. When the electrical resistance of the ion-exchange membrane is sufficiently low, it can be confirmed that the RED power generation performance is mainly influenced by the apparent permselectivity of the membrane. In addition, it was confirmed that the apparent permselectivity of the membranes can be improved through IEC, crosslinking degree, membrane thickness, surface modification, etc., and the optimum condition must be found in consideration of the trade-off relationship with electrical resistance.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.202-207
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• 2023

In the case of driving water electrolysis by receiving surplus electricity from solar and wind power generation, operation and stopping must be repeated according to weather fluctuations. When the PEMWE(Polymer Electrolyte Membrane Water Electrolysis) is driven and stopped, the PEM fuel cell is in the same state as the PEM fuel cell due to the residual hydrogen and oxygen, and the high potential of the water electrolysis formed during operation is highly likely to cause degradation of the electrode and membrane even during stopping. In this study, in order to check how much degradation of the electrode and membrane progresses during the repeated driving/shutdown process of PEM water electrolysis, the performance decrease was measured by changing the number of driving/shutdown for 144 hours. Changes in electrode catalyst active area, hydrogen permeability and fluorine emision rate of membranes were analyzed to measure changes in the properties of electrodes and polymer membranes. Overall, the PEMWE performance decreased as the number of stops increased. When stopped 5 times in 144 hours, the IrO_x catalyst activity decreased by more than 30%, and the hydrogen permeability increased by 80%, confirming that both the electrode and the membrane were deteriorated.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.667-672
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• 2023

This study proposes polymer electrolyte membrane fuel cell (PEMFC) based cogeneration system for greenhouse heating and cooling. The main scope of this study is to examine the proposed cogeneration system's suitability for the 660 m²-class greenhouse. A 25 kW PEMFC system generates electricity for two identical air-cooled heat pumps, each with a nominal heating capacity of 70 kW and a cooling capacity of 65 kW. Heat recovered from the fuel cell supports the heat pump, supplying hot water to the greenhouse. In cooling mode, the adsorption system provides cold water to the greenhouse using recovered heat from the fuel cell. As a result, the cogeneration system satisfies both heating and cooling capability, performing 175 and 145 kW, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.5
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• pp.481-494
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• 2005

The monitoring of persistent organic pollutants (POPs) in the atmosphere is a basis for the study of the fate of POPs in multimedia environments. Recently, passive air samplers (PASs) for POPs have been developed. In this paper, we deal with the principle, properties, and applications of the PAS. The principle of PAS, which has no pump, is physical sorption of semi-volatile organic chemicals on various sorbent materials. The PAS is much smaller than a high-volume air sampler and does not need electricity. These properties of the PAS make it possible to conduct various-scaled environmental monitoring all over the world including the Arctic and Antarctic, but the major disadvantage of PAS is its long sampling periods up to 2 years. To date, four kinds of PAS have been developed: polyurethane foam (PUF), polymer-coated glass (POG), semi-permeable membrane devices (SPMDs), and XAD resin-based PAS. Among them, SPMDs have been commercialized and are most widely used now. Meanwhile, the POPs emitted from China have a large potential to influence the levels and fates of POPs in Korea. Since characteristics of PAS are quite useful to monitor long-range transport of POPs, the use of PAS is highly recommended.