• 한국지구과학회지
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• 제26권6호
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• pp.477-488
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• 2005

제7차 교육과정의 초등학교 ‘과학’ ‘실험관찰’ 교과서와 서로 다른 출판사의 중·고등학교 과학과 지구과학 I, II교과서, 각각 4권씩을 대상으로 교과서에 수록된 화석사진을 분석하여 화석의 종류, 산출지역과 척도의 표기에 대한 분석결과 다음과 같은 결론을 얻었다. 초등학교의 ‘과학’, ‘실험관찰’ 교과서에 수록된 화석사진의 종류는 32개였으며, 중학교 과학교과서 4권에는 50개, 그리고 고등학교 8권의 교과서에서는 109개였다. 그러나 화석사진에서 표현되는 과학적 정보는 부족하였다. 초등학교의 과학교과서와 실험관찰에서는 수록된 화석사진의 $68\%$에 산출지가 표기되어 있었으며, 척도가 표기된 화석사진은 전체의 $6\%$였다. 중학교와 고등학교 교과서의 경우, 전체 화석의 $40\%$와 $16\%$에 산출지가 표시되어 있으며, 척도는 14%와 18%만이 표기되어 있었다. 보다 효과적인 과학교육의 목표를 달성하기 위해 과학교과서에 수록된 화석사진에 산출지와 척도를 표기할 필요가 있다.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.1112-1118
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• 2014

In island and backcountry areas, electrical power is usually supplied by diesel generators. It is difficult for small scale diesel generators to have an economy of scale owing to the usage of fossil fuels to produce electricity. Also, there is a problem of carbon dioxide emissions that brings some environmental pollution to the entire region of the area. For solving those, this paper proposes a design method of autonomous micro-grid to minimize the fossil fuels of diesel generator, which is composed of diesel generator, wind turbine, battery energy storage system and photovoltaic generation system. The proposed method was verified through computer simulation and micro-grid operation system.

• Nuclear Engineering and Technology
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• 제39권1호
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• pp.1-8
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• 2007

Hydrogen and electricity are expected to dominate the world energy system in the long term. The world currently consumes about 50 million metric tons of hydrogen per year, with the bulk of it being consumed by the chemical and refining industries. The demand for hydrogen is expected to increase, especially if the U.S. and other countries shift their energy usage towards a hydrogen economy, with hydrogen consumed as an energy commodity by the transportation, residential and commercial sectors. However, there is strong motivation to not use fossil fuels in the future as a feedstock for hydrogen production, because the greenhouse gas carbon dioxide is a byproduct and fossil fuel prices are expected to increase significantly. An advanced reactor technology receiving considerable international interest for both electricity and hydrogen production, is the modular helium reactor (MHR), which is a passively safe concept that has evolved from earlier high-temperature gas-cooled reactor (HTGR) designs. For hydrogen production, this concept is referred to as the H2-MHR. Two different hydrogen production technologies are being investigated for the H2-MHR; an advanced sulfur-iodine (SI) thermochemical water splitting process and high-temperature electrolysis (HTE). This paper describes pre-conceptual design descriptions and economic evaluations of full-scale, nth-of-a-kind SI-Based and HTE-Based H2-MHR plants. Hydrogen production costs for both types of plants are estimated to be approximately $2 per kilogram.

• 한국관개배수논문집
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• 제17권2호
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• pp.82-94
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• 2010

Recently, biomass application for energy is getting more interests from many countries since biomass is widely available over the nation wide, whereas fossil fuels are produced in several limited regions. Recognizing the importance, government is promoting renewable energy use in Korea. The locational characteristics of the existing biomass potential directly can be used to decide scale of power plant for local agricultural facility. Although there are a few studies on feasible biomass potential in local areas, it is expected that both government and commercial sectors recognize the potential of biomass energy and the importance of reducing greenhouse gases. When planning biomass energy systems, biomass price is determined by the costs of collection, transportation, chipping, drying if required. In this paper investigates the economic and spatial characteristic of biomass location by land use map. However typical area of each categories in local region is not correct to agricultural census data. Therefore we concerned about how to calculate feasible biomass potential which it can be describing total amount of plant scale, and to match both of data. Even though its spatial distribution, in rural area in Korea, to expand biomass energy programs in the area, government serve to find areas of higher biomass production with suitable locations for plants to convert to bio-energy in order to increase the usage of renewable energy.

• 한국디지털건축인테리어학회논문집
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• 제13권2호
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• pp.5-16
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• 2013

With regard to the new town developments which have supplied lots of houses in a short period of time in Korea this study aims to evaluation and finding out problems of the developments finally to suggest the direction. A new town's competitiveness model set in the previous paper takes a role of research frame to recognize the problems and to show the direction. The model explains that new town's competitiveness is composed of 4 factors; Self-sufficiency, Innovativenss, Identity and Sustainability. Problems of the developments are as follows; incongruity of spatial structure especially in the capital region, deficiency of self-sufficiency resulted from single-use development, restriction on mixed development by a number of regulations in capital region, low business value, grand scale of land compensation, house oriented planning guidance, unfair share of infrastructure fee, and physical structure depending mainly on fossil energy. Based on this recognition this study conclusively suggests corresponding direction such as role performance as a means of urban growth management, promotion of quality of life by accumulating social capital, introduction of socially sustainable management program for the new towns, discovery and creation of town's value, reexamination of self-sufficiency's meaning or target, selective deregulation of metropolitan development, institutional strategy for cost reduction, changeover from house index to urban function oriented index, and pursuit of low-carbon green town.

• 한국미생물·생명공학회지
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• 제41권2호
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• pp.207-214
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• 2013

화석연료의 매장량 한계와 해로운 영향으로 인하여 이를 대신할 대체 에너지연구가 요구되고 있다. 최근, 미세조류를 통한 바이오에너지 생산이 주목을 받고 있으며, 도시하수를 영양원으로 이용하여 미세조류를 배양하는 것은 생산비용을 낮추는 좋은 대안이 될 수 있다. 본 연구에서는 옥외 수질정화 배양 시스템(Small Scale Raceway Pond; SSRP)을 이용하여 적용했다. 실험에 사용한 도시하수는 하수종말처리장의 1차 침전지를 거친 유입수를 이용하였으며, 토착 미세조류를 SSRP에서 배양하였다. 체류시간 6일 운전 후 TN, TP, $NH_3-N$의 평균 제거 효율은 77.77%, 63.55%, 89.02%로 각각 나타났다. 또한 미세조류 내의 지질함량은 평균 19.51%로 나타났으며, FAME는 주로 18:n인 linolenate, linoleate로 이루어져 있음을 확인하였다. 18S rRNA 유전자 분석과 현미경 관찰을 통하여 녹조류인 Chlorella와 Scenedesmus가 우점하는 것을 확인하였다. 이러한 결과를 통하여 도시하수는 미세조류 배양에 필요한 질소와 인을 제공할 수 있으며, 미세조류를 이용한 SSRP를 통하여 정화될 수 있는 가능성을 확인하였다. 또한 미세조류 배양을 통해 얻어진 바이오매스는 바이오디젤 전환을 통하여 상업화될 수 있는 가능성을 확인하였다.

• 환경생물
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• 제32권1호
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• pp.26-34
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• 2014

에너지 소비의 증가와 화석 연료의 감소로 인해 바이오디젤과 같은 재생 가능한 대체 에너지 자원이 관심을 받고 있다. 미세조류를 이용한 바이오디젤은 기존의 농작물과 경쟁하지 않는 것과 더불어 많은 장점을 갖고 있다. 본 연구에서는 미세조류 배양의 생산 비용 절감과 축산 폐수 처리라는 두 가지 목표를 충족시키지 위해 돈분 액체 비료를 사용하였다. 옥외 배양 시스템(Small Scale Raceway Pond; SSRP)과 희석된 돈분 액체 비료를 이용하여 단일 미세조류 Chlorella sp. JK2, Scenedesmus sp. JK10 과 혼합 토착 미세조류 CSS를 20일 동안 각각 배양하였다. 미세조류 혼합균주인 CSS의 바이오매스 생산과 지질 생산성은 각각 $1.19{\pm}0.09gL^{-1}$, $12.44{\pm}0.38mgL^{-1}day^{-1}$로 단일 종에 비해 2배 이상 높았다. 돈분 액체 비료의 TN, TP의 제거율 역시 혼합 토착 미세조류 CSS에서 93.6%, 98.5%로 단일 종의 이용에 비해 30%이상 높은 제거 효율을 보여주었다. 이를 통해 돈분 액체 비료는 미세조류 배양에 필요한 N과 P를 제공하며, 미세조류를 이용한 SSRP를 통하여 영양염류를 제거할 수 있는 가능성을 확인하였다. 또한 미세조류 배양을 위한 생산 비용의 감소로 경제성 있는 바이오디젤의 생산 가능성을 확인하였다.

• Corrosion Science and Technology
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• 제4권6호
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• pp.242-249
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• 2005

A lot of parts in FGD (Flue Gas Desulfurization) systems of fossil-fuel power plants show the environments in which are highly changeable and extremely acidic corrosive medium according to time and locations, e.g. in duct works, coolers and re-heaters etc. These conditions are formed when system materials are immersed in fluid that flows on them or when exhausted gas is condensed into thin layered acidic medium to contact materials of the system walls and roofs. These environments make troublesome corrosion and air pollution problems that are occurred from the leakage of the condensed solution. To cathodically protect the metallic structures in extremely acidic fluid, the properties of the protective coatings on the metal surface were very important, and epoxy Novolac coating was applied in this work. On the base of acid immersion tests, hot sulfuric acid decreased the hardness of the coatings and reduced greatly the content of $Na_2O$, $Al_2O_3$, and $SiO_2$ among the main components of the coating. A special kind of CP(Cathodic Protection) system has been developed and tested in a real scale of the FGD facility. Applied coating for this CP system was peeled off and cracked in some parts of the facility. However, the exposed metal surface to extremely acidic fluid by the failure of the coatings was successfully protected by the new CP system.

• 동력기계공학회지
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• 제15권5호
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• pp.16-21
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• 2011

The large scale decisive battle will be gradually reduced on the sea in the future and surface combatant ship installed advanced weapon units as well as propulsion system will be continuously increased. The high level of military technology leads to appear state-of-the-art weapon system using high power energy. As a results, fossil fuel powered main prime mover as diesel engine and gas turbine which are composed of mechanical propulsion system should be decreased from combatant ship in the near future. The new building naval combatant ship with the latest technology has electric based propulsion method of the hybrid type combined with mechanical and electrical drive. U.S. and Royal Navy, especially, select the integrated fully electric based propulsion system for the next generation combat ship and play an important roll for developing them. In this context, this paper was focused on the deduction of implications through analyzing the combatant ship propulsion system using diesel and gas turbine engine which are promoted on the worldwide.

• 한국정밀공학회지
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• 제30권2호
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• pp.137-142
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• 2013

The indiscriminate use of the fossil fuel has caused serious environmental pollutions such as the shortage of energy and global warming. Microalgae have being emphasized as $3^{rd}$ generation biomass which makes the carbon dioxide reduce effectively as well as produces the biofuel. Large scale production of microbial biomass by continuous culture is a quite challenging issue, because off-line optimization strategies of a microbial process utilizing a model-based scheme give rise to many difficult problems. In this paper, the static and simple control method which was able to be applied in time-variant growth environment and large scale of algae culture was studied. The significant disturbances in on-line measurement of cell density were reduced by Savitzky-Golay FIR smoothing filter. Dunaliella salina was cultivated continuously in a flat panel photobioreactor by the on-off control of the turbidostat process.