• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.96-103
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• 1996

The objectives of this study were to examine the biodegradation of phenol using the anaerobic fluidized bed reactor(AFBR). Mixed microorganisms were selected from the anaerobic digestion tank, and could be adapted to high concentration of phenol by increasing the phenol concentration 600-3600 mg/l step by step. The results were summarized as follows: 1. The average removal efficiency of phenol was 90%, decreased by increasing concentration of phenol, and then a shock range was 1200~2400 ppm. 2. The production rate of biogas in overall limits was proportional to the concentration of influent phenol. 3. At steady state, compositions of gases were $CH_4$ 55~60%, $C0_2$ 34~43%, respectively. These were similar to that of the theoretical estimates. 4. The production rates of biogas and methane per the molarity of phenol removed were linearly increased, 56.45 l gas/mol-phenol and 29.20 l $CH_4/mol$-phenol. Using this biogas, the recoverable energy was 269.1 kcal/mol phenol. It was 120.2 kcal/g-COD, transforming into the chemical oxygen demand. 5. The bulk of microorganisms existed in suspended section of fluidized bed with type of biofilm and its concentration was 340 mg/g-media. In conclusion, the anaerobic treatment of pure phenol was possible and its removal efficiency, introducing the AFBR, was successful. Also toxic organic compound such as phenol was biodegradable and was recoverable as resource of energy.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.4
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• pp.101-107
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• 2009

The energy efficiency of existing lighting appliances has continuously been improving due to the government aid such as rebate programs and information of energy saving, etc. However, the usage pattern of lighting appliance at this moment has more been increasing higher illumination and indirect lighting method according that the taste of customers has changed variously. This paper estimates the economic evaluation and simulation for FPL45[W] lamp & ballast instead of FPL55 lamp & ballast in order to study the governmental support to demand side management.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.386-390
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• 2007

By use of a simple two-point extrapolation scheme estimating the correlation energies of the molecules along with the basis sets specifically targeted for extrapolation, we have shown that the MP2 basis set limit binding energies of large hydrogen-bonded complexes can be accurately predicted with relatively small amount of computational cost. The basis sets employed for computation and extrapolation consist of the smallest correlation consistent basis set cc-pVDZ and another basis set made of the cc-pVDZ set plus highest angular momentum polarization functions from the cc-pVTZ set, both of which were then augmented by diffuse functions centered on the heavy atoms except hydrogen in the complex. The correlation energy extrapolation formula takes the (X+1)-3 form with X corresponding to 2.0 for the cc-pVDZ set and 2.3 for the other basis set. The estimated MP2 basis set limit binding energies for water hexamer, hydrogen fluoride pentamer, alaninewater, phenol-water, and guanine-cytosine base pair complexes of nucleic acid by this method are 45.2(45.9), 36.1(37.5), 10.9(10.7), 7.1(6.9), and 27.6(27.7) kcal/mol, respectively, with the values in parentheses representing the reference basis set limit values. A comparison with the DFT results by B3LYP method clearly manifests the effectiveness and accuracy of this method in the study of large hydrogen-bonded complexes.

• New & Renewable Energy
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• v.3 no.3
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• pp.28-35
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• 2007

In this study, the wave power resources at the three locations [Sokcho, Hupo, and Onsan] on the east coast of Korea were estimated by using the field measurement data and were compared with the results of previous researches. It was found that seasonal variation of the wave power is very significant on the east coast of Korean peninsula. The wave power was the smallest in the summer season at all the locations. At Hupo and Onsan, the highest value of the monthly-averaged wave power was observed in September, probably because the pathways of typhoon in September were close to both locations. At the northest location, Sockcho, in contrast, the monthly highest value of the wave power appeared in January, probably owing to the influence of storm waves driven by Donghae twister. The estimated annual average wave power was 4.5 kW/m at Sokcho, which was about two times larger than those at other two locations. It is noteworthy that this result is completely different from past researches based on wave hindcasting data. In addition, the estimates of wave power by the past researches seemed to be smaller than those of the present study, especially at the northern region of the east coast.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.10
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• pp.399-409
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• 2006

This paper presents a novel method for satisfying the thermal comfort of indoor environment and reducing the summer peak demand power by minimizing the power consumption for an Air-conditioner within a space. Korea Electric Power Corporation (KEPCO) use the fixed duty cycle control method regardless of the indoor thermal environment. However, this method has disadvantages that energy saving depends on the set-point value of the Air-Conditioner and direct load control (DLC) has no net effects on Air-conditioners if the appliance has a lower operating cycle than the fixed duty cycle. In this paper, the variable duty cycle control method is proposed in order to compensate the weakness of conventional fixed duty cycle control method and improve the satisfaction of residents and the reduction of peak demand. The proposed method estimates the predict mean vote (PMV) at the next step with predicted temperature and humidity using the back propagation neural network model. It is possible to reduce the energy consumption by maintaining the Air-conditioner's OFF state when the PMV lies in the thermal comfort range. To verify the effectiveness of the proposed variable duty cycle control method, the case study is performed using the historical data on Sep. 7th, 2001 acquired at a classroom in Seoul and the obtained results are compared with the fixed duty cycle control method.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.1
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• pp.137-151
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• 1988

Thurbulent thermal convection between two plates, bottom plate is at higher temperature $T_{h}$ and the upper plate is at lower temperature $T_{i}$ is numerically investigated. Model equations are abridged Reynolds stress equations; full Reynolds stress equations are simplified to yield algebraic relations in case of mean square velocity fluctuations in vertical and horizontal directions. Boundary conditions for turbulent kinetic energy k and mean square temperature variance .thera.$^{2}$oner bar at the plate surfaces are set to be zero and those of dissipation rate of turbulent kinetic energy .epsilon. and dissipation rate of mean square temperature variance .epsilon.$_{\theta}$ are assumed at first grid point nearest to the boundary surfaces, whose values are approximated by inviscid estimates. Results show that temperature profiles are in good agreement with experimental data except transition region, in which temperature is over-predicted. Such discrepancy becomes larger as the Rayleigh number becomes smaller. Nusselt numbers, which are calculated from the temperature gradients at the boundary surfaces, are also in good agreement with experimental data.a.a.

• Smart Media Journal
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• v.8 no.4
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• pp.72-79
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• 2019

The automated demand response (DR) program encourages consumers to participate in grid operation by reducing power consumption or deferring electricity usage at peak time automatically. However, successful deployment of the automated DR program sphere needs careful assessment of appliances load profile (ALP). To this end, the recent method estimates frequency, consistency, and peak time consumption parameters of the daily ALP to compute their potential score to be involved in the DR event. Nonetheless, as the daily ALP is subject to varying with respect to the DR time ALP, the existing method could lead to an inappropriate estimation; in such a case, inappropriate appliances would be selected at the automated DR operation that effected a consumer comfort level. To address this challenge, we propose a more proper method, in which all the three parameters are calculated using ALP that overlaps with DR time, not the total daily profile. Furthermore, evaluation of our method using two public residential electricity consumption data sets, i.e., REDD and REFIT, shows that our energy management systems (EMS) could properly match a DR target. A more optimal selection of appliances for the DR event achieves a power consumption decreasing target with minimum comfort level reduction. We believe that our approach could prevent the loss of both utility and consumers. It helps the successful automated DR deployment by maintaining the consumers' willingness to participate in the program.

• Macromolecular Research
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• v.17 no.8
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• pp.603-608
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• 2009

Novel ultra-high molecular weight polyethylene (UHMWPE)/zirconia composites were previously prepared by the in situ polymerization of ethylene using a Ti-based Ziegler-Natta catalyst supported on to the surface of zirconia, as a bearing material for artificial joints. Tribological tests revealed that a uniform dispersion of zirconia in UHMWPE markedly increased the wear resistance. The effects of zirconia content on the oxidation behavior of the ${\gamma}$-ray-treated UHMWPE/zirconia composite surfaces were examined. The oxidation index that estimates the oxidation degree as the content of total carbonyl compounds was monitored using Fourier transform infrared spectroscopy-attenuated total reflectance. The changes in the surface composition due to the oxidation were confirmed by electron spectroscopy for chemical analysis. The extent of oxidation decreased with increasing zirconia content, which was attributed to the increased crystallinity as well as the decreased polymer portion of the UHMWPE/zirconia composites.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2910-2917
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• 2020

Digital light processing three-dimensional (3D) printing technique is a powerful tool to rapidly manufacture plastic scintillators of almost any shape or geometric features. In our previous study, the main properties of light output and transmission were analyzed. However, a more detailed study of the other properties is required to develop 3D printed plastic scintillators with expectable and reproducible properties. The 3D printed plastic scintillator displayed an average decay time constants of 15.6 ns, intrinsic energy resolution of 13.2%, and intrinsic detection efficiency of 6.81% for 477 keV Compton electrons from the ¹³⁷Cs γ-ray source. The 3D printed plastic scintillator showed a similar decay time and intrinsic detection efficiency as that of a commercial plastic scintillator BC408. Furthermore, the presented estimates for the properties showed good agreement with the analyzed data.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1625-1629
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• 2009

The new paradigm called 'Low Carbon Green Growth' involved in reducing greenhouse gas is on the rise as a critical issue worldwide. The essential of Kyoto protocol issued in 1997 is to achieve the sustainable economic growth environments by converting existing production system to eco-friendly one. The protocol imposes the liability to reduce greenhouse gas to the countries joined to it. The paradigm is directly involved in the energy consumption and environmental pollution caused by construction activities. Value Engineering which are mainly applied in the design phase in practice is a measure to improve the value of a constructed facility by analyzing and/or appraising the functions and costs of it. However, an appropriate method which assesses eco-friendliness of constructed facility has not been propose by researchers. This paper proposes a method which assesses the performance involved in eco-friendliness of constructed facility using Value Engineering (VE) in the design phase. The method estimates the environmental cost relative to the amounts of energy consumption and environmental pollution occurred over the entire project life cycle. The database called "Life Cycle Inventory DB", which stores information about the amounts of environmental pollution, is used. The algorithm which retrieves the amounts of environmental pollutions from the DB and converts them into environmental costs is developed. The algorithm is implemented into a system which quantifies the eco-friendliness of constructed facility in the design phase using VE.