• Nuclear Engineering and Technology
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• 제55권8호
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• pp.3046-3053
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• 2023

Radon is a naturally occurring carcinogenic agent, poses a serious health hazard when inhaled or ingested in significant amounts. The water of the Padma river will be used as a tertiary coolant for the soon-to-be-commissioned 'Rooppur Nuclear Power Plant'. Hence, it is important to assess the radiological status of the river prior to the commission of this power plant. Therefore, for the first time, 25 samples of water were collected from various locations of the Padma River and analyzed for radon concentration using the RAD H₂O (DURRIDGE) radon monitoring device. The radon concentrations were found in the range from 0.077 ± 0.036 to 0.494 ± 0.211 Bq/L with a mean of 0.250 ± 0.093 Bq/L. All the concentrations were found to be below the recommended limits of WHO (100 Bq/L) and USEPA (11.1 Bq/L). The mean annual effective dose due to the radon exposure via inhalation and ingestion pathways were 0.638 µSv/y and 0.629 µSv/y, respectively, which were all well below the annual effective dose recommended by WHO (0.1 mSv/y). Since Bangladesh lacks a national safety limit of radon in water, this pioneering study provides baseline data on radon levels for the environment around Rooppur Nuclear Power Plant.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1377-1384
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• 2018

Accurate measurement of the absorbed dose and the effective dose is required in dental panoramic radiography involving relatively low energy with a rotational X-ray tube system using long exposures. To determine the effectiveness of measuring the irradiation by using passive dosimetry, we compared the entrance skin doses by using a radiophotoluminescent glass dosimeter (RPL) and an optically stimulated luminescence detector (OSL) in a phantom model consisting of nine and 31 transverse sections. The parameters of the panoramic device were set to 80 kV, 4 mA, and 12 s in the standard program mode. The X-ray spectrum was applied in the same manner as the panoramic dose by using the SpekCalc Software. The results indicated a mass attenuation coefficient of $0.008226cm^2/g$, and an effective energy of 34 keV. The equivalent dose between the RPL and the OSL was calculated based on a product of the absorbed doses. The density of the aluminum attenuators was $2.699g/cm^3$. During the panoramic examination, tissue absorption doses with regard to the RPL were a surface dose of $75.33{\mu}Gy$ and a depth dose of $71.77{\mu}Gy$, those with regard to the OSL were surface dose of $9.2{\mu}Gy$ a depth dose of $70.39{\mu}Gy$ and a mean dose of $74.79{\mu}Gy$. The effective dose based on the International Commission on Radiological Protection Publication 103 tissue weighting factor for the RPL were $0.742{\mu}Sv$, $8.9{\mu}Sv$, $2.96{\mu}Sv$ and those for the OSL were $0.754{\mu}Sv$, $9.05{\mu}Sv$, and $3.018{\mu}Sv$ in the parotid and sublingual glands, orbit, and thyroid gland, respectively. The RPL was more effective than the OSL for measuring the absorbed radiation dose in low-energy systems with a rotational X-ray tube.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.291-295
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• 2009

As a reasonable energy policy has become required because of consuming substantial amounts of oil than others, the studies on energy consumption are in work for energy savings of buildings that spend up to 24% of total energy consumption. However, there aren't basic data on energy consumption and installationregulations for effective equipments in energy guzzled buildings. The best plan to reduce the building energy consumption is that the insulation performance should be improved because the insulation and airtight of building envelopes have an effect on the energy consumption basically. Thus, we should prepare the alternatives to improve insulation performance of envelopes and the efficiency of insulation performance of the window for reducing energy consumption.

• 자원ㆍ환경경제연구
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• 제12권2호
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• pp.275-298
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• 2003

본 연구에서는 탄소세와 에너지세의 부과가 우리나라의 에너지수요에 미치는 영향과 두 조세의 정책효과를 META Net모형을 이용하여 분석한다. 본 연구는 CGE 모형이나 거시계량모형을 이용한 기존 연구와는 달리 상향모형인 META Net모형을 이용하여 탄소세와 에너지세가 우리나라의 에너지시스템에 미치는 영향을 비교분석하였다. 연구결과에 의하면 일정한 온실가스 감축량을 달성하는데 있어 탄소세가 에너지세보다 비용효과적이지만 국내 기후정책수단으로 에너지세 역시 중요한 정책수단임을 알 수 있다. 에너지세의 경우에 탄소세에 비해 에너지소비가 더 크게 감소하기 때문에 에너지절약과 에너지효율기술 개발의 더 큰 유인을 제공한다. 또한 에너지세는 주어진 탄소감축량을 에너지 열량 기반의 조세를 통해 달성하기 때문에 탄소세에 비해 에너지가격을 크게 상승시켜 탄소세에 비해 조세수입이 더 크다. 따라서 에너지세의 도입은 관련 기술개발에 대한 유인을 제공하는 동시에 그 개발에 필요한 재원을 조달하는 적절한 방법이 될 수 있을 것이다.

• 한국콘텐츠학회논문지
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• 제21권10호
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• pp.422-433
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• 2021

신재생 에너지에 관한 적극적 사업 참여가 필요한 현 시점에서, 신재생 에너지 사업 참여의 성장동력과 내실있는 추진전략에 대한 기초정보가 필요하였다. 이에 따라 본 연구는 다층모형을 활용한 신재생 에너지 사업참여 로드맵에 미치는 영향 요인을 분석하여, 신재생 에너지 사업 참여 활성화를 위한 기초정보를 제공하고자 하였다. 본 연구결과, 실효성있는 신재생 에너지 사업 참여 로드맵을 달성하기 위해서는 업종별 신재생 에너지사업 참여 요소의 재정립이 필요함을 살펴볼 수 있다. 구체적으로 살펴보면, 사업의 주도 단체, 이익배분 방식, 녹색산업 금융지원, 사업 시행 방식, 발전소 위치, 포괄적 장기전략 등의 적절한 대응방안 마련이 필요하고, 관련 산업의 육성을 촉진할 수 있는 제도적 접근이 필요할 것임을 발견하였다. 무엇보다 실효성있는 신재생에너지 사업 참여 로드맵을 달성하기 위해서는 국가경제에의 부담을 최소화하면서 신재생에너지의 보급을 확대하고 관련 산업의 육성을 촉진할 수 있는 제도적 접근이 필요함을 시사하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.135-147
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• 2015

Remediation of metal(loid)s-contaminated sites is crucial to protect human and ecosystem. Solidification and stabilization of metal(loid)s by the binder amendment is one of the cost-effective technologies. In this study, metal (loid)s in various field-contaminated soils obtained from steel-making, metal refinery and mining tillage were immobilized by the application of single binders such as diammonium phosphate (DAP), lime, and ladle slag. The efficiency of solidification and stabilization was evaluated by Toxicity Characteristic Leaching Procedure (TCLP) and the Standard, Measurements and Testing programme of European Union (SM&T) extraction processes. In terms of TCLP extraction, the binder was effective in order of lime > DAP > ladle slag. All binders were highly effective in the immobilization of Pb, Zn, Cu, Ni, and Cd. The increased immobilization efficiency is attributed to the increase in the Step III and IV fractions of the SM&T extraction. Lime and ladle slag were highly effective in the immobilization of the metal(loid)s, however, As release increased with DAP due to competition between the phosphate originated from DAP and arsenate. A further study is needed for the better immobilization of multi metal(loid)s using binary binders.

• Progress in Superconductivity
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• 제13권2호
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• pp.133-138
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• 2011

To reduce the processing cost of the single grain REBCO (RE: Rare-earth elements) bulk superconductors, a cost-effective process should be developed. One possible way of developing the cost-effective process is the use of low-cost precursor powders. In this study, the single grain YBCO superconductors were fabricated using a home made powder. $YBa_2Cu_3O_{7-y}$ (Y123) powders were synthesized at $850-900^{\circ}C$ in air by the powder calcination method with repeated crushing and heat treatment steps. The processing parameters for the fabrication of single grain Y123 bulk superconductors, $T_{max}$ (maximum temperature), $T_p$ (peritectic temperature) and a cooling rate through $T_p$ were optimized. To enhance the flux pinning capacity of the single grain Y123 samples, $Y_2BaCuO_5$ (Y211) particles were dispersed in the Y123 matrix by adding $Y_2O_3$ powder to the calcined Y123 powder. Applying the optimized processing condition, the single grain Y123 superconductors with $T_c=91\;K$ and $J_c=1.5{\times}10^4\;A/cm^2$ at 2 T were successfully fabricated using a home made powder. The levitation forces and trapped magnetic field at 77 K measured using a Nd-B-Fe permanent magnet of 5300 G were 47 N and 3000 G, respectively, which are comparable to those obtained for the samples fabricated using a commercial grade Y123 powders.

• 한국방사선학회논문지
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• 제9권6호
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• pp.375-379
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• 2015

이 연구의 목적은 다종에너지 X선 빔의 유효에너지를 결정하는데 있다. 80 kVp X선 빔에 대한 알루미늄의 반가층은 광자극형광나노닷선량계들(OSLnDs)을 사용하여 측정하였다. 선감쇠계수(${\mu}$)는 측정된 반가층을 사용하여 계산하였다. 그리고 질량감쇠계수(${\mu}/{\rho}$)는 알루미늄의 밀도로 선감쇠계수를 나누어 얻었다. 얻어진 질량감쇠계수의 유효에너지($E_{eff}$)는 미국표준기술연구소(NIST)에서 주어진 알루미늄의 광자에너지들에 대한 X선질량감쇠계수들의 자료를 사용하여 결정하였다. 결과로서, 반가층, 선감쇠계수 및 질량감쇠계수는 각각 2.262 mmAl, $3.06cm^{-1}$, $1.114cm^2/g$이다. 그리고 유효에너지는 29.79 keV에서 결정되었다.

• Nuclear Engineering and Technology
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• 제26권2호
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• pp.285-293
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• 1994

압축 벤토나이트에서 핵종이동은 확산에 의해 지배된다. 국산 벤토나이트에 대한 음이온핵종의 확산 특성 규명을 위해서 요오드이온을 대상으로 관통확산실험을 수행하였다. 대상매질은 동해안 지역의 벤토나이트를 사용하였으며, 실험용액은 합성 모의지하수에 I-125를 첨가하여 사용하였다. 압축 벤토나이트의 충전밀도는 1.2, 1.4, 1.7Mg/㎥등 세가지로 하였다. 요오드이온의 겉보기확산계수와 유효확산계수는 충전밀도가 증가함에 따라 감소하였고, 이들 확산계수의 값은 각자 3.80-7.12$\times$$10^{-11}$ $m^2$/s와 1.25-7.97$\times$$10^{-12}$ $m^2$/s의 범위에 있었다. 실험결과, 겉보기확산계수는 벤토나이트의 공극구조에 의존하였으며, 유효확산계수는 공극구조는 물론 핵종확산이동에 이용된 유효공극율에 의해 좌우되었다. 본 연구에서 얻어진 결과는 처분장안전성평가의 기초자료로 활용될 것이다.

• 지식경영연구
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• 제9권4호
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• pp.51-63
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• 2008

Effective energy consumption now becomes one of the area of knowledge management which potentially gives global impact. It is considerable for the energy management to optimize the usage of energy, rather than decreasing energy consumption at any cases. To resolve these challenges, an intelligent and personalized system which helps the individuals control their own behaviors in an optimal and timely manner is needed. So far, however, since the legacy energy management systems are nation-wide or organizational, individual-level energy management is nearly impossible. Moreover, most estimating methods of energy consumption are based on forecasting techniques which tend to risky or analysis models which may not be provided in a timely manner. Hence, the purpose of this paper is to propose a novel individual-level energy management system which aims to realize timely and personalized energy management based on context-aware computing approach. To do so, an index model for energy consumption is proposed with a corresponding service framework.