• Title/Summary/Keyword: Specific energy input

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The Impact of Population Aging on Energy Use and Carbon Emissions in Korea (인구 고령화가 에너지 사용과 탄소 배출에 미치는 영향)

  • Kim, Dong Koo;Park, Sunyoung
    • Journal of Environmental Policy
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    • v.13 no.2
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    • pp.99-129
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    • 2014
  • This research estimates the impact of population aging on energy use and carbon emissions by energy sources and by industrial sectors in Korea until 2035. For the estimation, the structural change in household consumption expenditure identified by the age-specific consumption pattern was analyzed in conjunction with energy and environment input-output tables. The estimation result presents that, despite the population aging, energy use and carbon emissions induced by household consumption continue to increase until 2026, and then that elevated levels of energy use and carbon emissions will be maintained for a considerable period of time. According to the estimation by energy sources, the use of natural gas will show substantial increase while the use of crude oil will switch to a downturn at a relatively early period. According to the estimation by industrial sectors, carbon emissions in the sectors with relatively high consumption share of old households such as medical health, dwelling, lighting, heating, air-conditioning, and food will have substantial increase, whereas those in the sectors associated with education, transport, catering, and accommodation services will turn downward relatively early. In addition, the study analyzes through policy simulation the impact of aging-related policy similar to the basic pension system, which is recently being discussed for legislation, on energy use and carbon emissions.

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Sonochemical Effects using Multi-stepped Ultrasonic Horn (다단 혼 형태의 초음파 장비를 이용한 초음파 화학적 효과 연구)

  • Choi, Jongbok;Lee, Seongeun;Son, Younggyu
    • Journal of Soil and Groundwater Environment
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    • v.25 no.4
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    • pp.58-66
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    • 2020
  • Since the typical horn-type ultrasonic equipment induces a reaction at the probe tip, the sonochemical reaction has a limitation that it occurs only in a specific area. As one of the ways to overcome this limitation, an ultrasonic device with multi-stepped horn equipped with several oscillators has been developed. The objective of this study was to investigate the sonochemical effects induced by acoustic cavitation system in 20 kHz multi-stepped ultrasonic horn using calorimetry, KI dosimetry and the luminol test. The sonochemical effects of multi-stepped ultrasonic horn were compared with that of the typical horn-type 20 kHz ultrasonic device. The effect of immersion depth and power on the sonochemical reaction was investigated in the ultrasonic system with multi-stepped ultrasonic horn. Higher calorimetric energy was obtained at higher immersion depth and power conditions. Sonochemical effects increased significantly when using the high immersion depth and input power. However, as the input power increased, the cavitation reaction zone concentrated around the ultrasonic horn. Additionally, the experiments to examine the effect of liquid temperature was conducted. The smaller sonochemical reaction was obtained for the higher liquid temperature. The effect on temperature seems to be closely related to liquid conditions such as viscosity and vapor pressure of water.

Evaluation of Energy Production for a Small Wind Turbine by Considering the Geometric Shape of the Deokjeok-Do Island (덕적도 지형을 고려한 소형풍력발전기 발전량 평가)

  • Jang, Choon-Man;Lee, Sang-Moon;Jeon, Wan-Ho;Lim, Tae-Gyun
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.6
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    • pp.629-635
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    • 2014
  • This paper presents annual energy production (AEP) by a 1.5kW wind turbine due to be installed in Deokjeok-Do island. Local wind data is determined by geometric shape of Deokjeok-Do island and annual wind data from Korea Institute of Energy Research at three places considered to be installed the wind turbine. Numerical simulation using WindSim is performed to obtain flow pattern for the whole island. The length of each computation grid is 40 m, and k-e turbulence model is imposed. AEP is determined by the power curve of the wind turbine and the local wind data obtained from numerical simulation. To capture the more detailed flow pattern at the specific local region, Urumsil-maul inside the island, fine mesh having the grid length of 10m is evaluated. It is noted that the input data for numerical simulation to the local region is used the wind data obtained by the numerical results for the whole island. From the numerical analysis, it is found that a local AEP at the Urumsil-maul has almost same value of 1.72 MWh regardless the grid resolutions used in the present calculation. It is noted that relatively fine mesh used for local region is effective to understand the flow pattern clearly.

Effects of Feed Moisture on the Physicochemical Properties of Extruded Corn Fibers (수분주입량에 따른 압출성형 옥수수 섬유질의 물리화학적 특성)

  • Kim, Cheol-Hyun;Ryu, Gi Hyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.3
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    • pp.427-433
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    • 2013
  • This study was designed to examine changes in the physicochemical properties of extruded corn fibers with different amounts of feed moisture (30, 40, and 50%). The screw speed and die temperature were fixed to 200 rpm and $140^{\circ}C$, respectively. The crude ash, fat, and protein in corn fiber decreased from the extrusion process. The insoluble dietary fiber in corn fibers decreased, while soluble dietary fiber increased at a feed moisture of 30%. The specific length of the extruded corn fiber increased while the specific mechanical energy input, density, breaking strength, and elastic modulus decreased. The water absorption index (WAI) and reducing sugar content of the corn fibers did not significantly change, but the water soluble index (WSI) decreased as the feed moisture content of the corn fiber increased. On the other hand, the WAI of de-starched corn fiber decreased while WSI and reducing sugars increased as the feed moisture content of the corn fiber increased.

A Method for Estimating Input-output Tables with Disaggregated Sector (부문 분리된 산업연관표 추계방법)

  • Kiho Jeong
    • Environmental and Resource Economics Review
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    • v.31 no.4
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    • pp.849-864
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    • 2022
  • In case of a specific sector being divided into sub-sectors, this study presents a process for estimating an input-output table, which is frequently used as basic data in fields of energy and environment economics. RAS method, which is universally used for this case, requires information on production, intermediate input sum, and intermediate demand sum for each sector in the new table. But in many cases, it is difficult to secure information on intermediate demand sum by sector. This study suggests a process for estimating a new input-output table without using information of intermediate demand sum in the case of sector separation, under the assumption that information of production value and intermediate input sum by sector are available. The key idea is that the values of many elements in the input-output table after disaggregation are the same as those in the table before disaggregation and that the sum of the elements after disaggregation, equals the values of the elements before disaggregation. The process of estimating the intemediate transaction matrix or the input coefficient matrix is presented by using these information instead of intermediate demand sum information. A small-scale simulation shows that the average error rate of the process proposed in this study is about 11.23% in estimating input coefficients, which is smaller than the 11.30% estimation error of RAS using the information of intermediate demand sum. However, since it is known in the literature that using additional information does not always improve estimation performance compared to not using it, additional research on various simulations is needed to apply the method of this study to reality.

Analysis of the Protective Distance of Low-Voltage Surge Protective Device(SPD) to Equipment (저압용 서지 보호 장치(SPD)의 보호 거리 해석)

  • Lee, Jung-Woo;Oh, Yong-Taek
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.4
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    • pp.28-34
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    • 2012
  • Installing surge protection devices for a low-voltage system is important to ensure the survival of electric or electronic devices and systems. If surge protection devices (SPD) are installed without consideration of the concept of lightning protection zones, the equipment to be protected might be damaged despite the correct energy coordination of SPDs. This damage is induced by the reflection phenomena on the cable connecting an external SPD and the load protected. These reflection phenomena depend on the characteristics of the output of the external SPD, the input of the loads, and the cables between the load and the external SPD. Therefore, the SPD has an effective protection distance under the condition of the specific load and the specific voltage protection level of SPD. In this paper, PSCAD/EMTDC software is used to simulate the residual voltage characteristics of SPD Entering the low-voltage device. And by applying a certain voltage level, the effective protection distances of SPD were analyzed according to the each load and length of connecting cable, and the effectiveness of SPD were verified.

The Analysis on the Relationship between R&D Productivity of Renewable Energy and Emission Trading Scheme; Using OECD Patent Data (신재생에너지의 R&D 생산성과 배출권거래제의 연관관계 분석: OECD 특허데이터를 중심으로)

  • Kim, Suyi
    • Environmental and Resource Economics Review
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    • v.22 no.1
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    • pp.53-76
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    • 2013
  • This paper analyzed on the relationship between R&D productivity of renewable energy and the Emissions Trading Scheme using OECD's country-specific patents and R & D input data. We empirically tested whether this R & D productivity has been substantially improved before and after the implementation of the emissions trading scheme and whether emission trading scheme has been promoted technology progress of renewable energy. Analytical methods used in this study, Negative Binomial Models which was proposed by Hausman et al. (1984). According to the results of this analysis, the R & D productivity of renewable energy was improved by emissions trading scheme, which was statistically significant at the 99% confidence interval [CI]. The R&D productivity of renewable energy was higher in Annex I countries. This research is significant in that R&D productivity was analyzed in associated with the emission trading scheme rather than it was analyzed by simply comparing R&D productivity.

Construction and Evaluation of Scaled Korean Side Impact Dummies

  • Kim, Seong-Jin;Kwon Son;Park, Kyung-Hyun
    • Journal of Mechanical Science and Technology
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    • v.17 no.12
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    • pp.1894-1903
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    • 2003
  • It is necessary to have a dummy that describes the anthropometry of a victim with accuracy. This study presents three scaled side impact dummies constructed for the use of MADYMO. They represent five, fifty and ninety-five percentile Korean males ranged from the age of 25 through 39. Thirty-five anthropometric data were used to scale input files required for MADYSCALE. Geometries, inertia, joints and other parameters for dummies were scaled based on the configurations of EuroSID-1. This study proposes the lateral impact response requirements for head, thorax and pelvis of Korean side impact dummies. A lateral drop impact test was conducted for the head at the height of 200 mm. Lateral pendulum impact tests were also carried out for thorax and pelvis at three specific impact velocities. All these test results were obtained from simulation based on MADYMO. All the procedures of the three tests followed the requirement of ISO/TR 9790.

Investigating Buck DC-DC Converter Operation in Different Operational Modes and Obtaining the Minimum Output Voltage Ripple Considering Filter Size

  • Babaei, Ebrahim;Mahmoodieh, Mir Esmaeel Seyed;Sabah, Mehran
    • Journal of Power Electronics
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    • v.11 no.6
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    • pp.793-800
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    • 2011
  • This paper investigates the operational modes of buck dc-dc converters and their energy transmission methods. The operational modes of such converters are classified in two types, discontinuous conduction mode (DCM) and continuous conduction mode (CCM). In this paper, the critical inductance relation of DCM and CCM is determined. The equations of the output voltage ripple (OVR) for each mode are obtained for a specific input voltage and load resistance range. The maximum output voltage ripple (MOVR) is also obtained for each mode. The filter size is decreased and the minimum required inductance value is calculated to guarantee the minimization of the MOVR. The experimental and simulation results in PSCAD/EMTDC prove the correctness of the presented theoretical concepts.

Enhanced performance at an early state of hydrocarbon selective catalyst reduction of NOx by atmospheric pressure plasma

  • Nguyen, Duc Ba;Heo, Il Jeong;Mok, Young Sun
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.372-379
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    • 2018
  • The improvement of $NO_x$ reduction by $Ag/{\gamma}-Al_2O_3$ with a hydrocarbon ($n-C_7H_6$) in the early state was investigated in a packed-bed dielectric barrier discharge plasma reactor. The results revealed that the combination of plasma with the catalyst enhanced $NO_x$ reduction efficiency at low operating temperatures, depending on the temperature and specific input energy. To sum up, the poor performance of the catalytic $NO_x$ reduction at low temperatures in the early stage before reaching thermochemical steady state can be greatly compensated for by using the atmospheric-pressure plasma generated in the catalyst bed.