• 한국건설관리학회논문집
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• 제10권5호
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• pp.95-103
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• 2009

하천시설공사의 경우, 비정형적인 하천공사의 특성과 개략 공사비 산정을 위한 기준단가의 부재와 기본 설계단계 부재에 따른 가용정보의 부족 및 변동의 가능성 등의 특정으로 개략공사비 산정에 많은 어려움이 존재한다. 기존의 하천공사의 개략공사비 산정은 하천제방의 대표 단면의 물량 산출을 통한 대표 단면 공사비 산정 후, 이에 단순히 연장(m)을곱하는 방식을 적용하고 있다. 본 연구에서는 체계적인 개략공사비 산정 방법론이 존재하지 않는 하천공사의 개략공사비 산정 방법론을 제시하는데 있어, 기본설계가 없는 하천시설물공사의 특성을 고려해 기획단계에서의 개략공사비 산정 모델을 개발하고자 한다. 이를 통해 국가예산이 투입되는 공공공사에서 국가예산의 낭비를 방지하고, 보다 체계적이고 정확한 공사비 산출을 가능하게 하고자 한다.

• 대한환경공학회지
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• 제32권10호
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• pp.928-935
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• 2010

폐 목재 소각 보일러 배가스로부터 질소산화물을 저감하기 위하여 설치된 선택적촉매환원 공정의 시운전 중에 전단에 설치된 여과포의 일부 소실이 발생되었다. 여과포 소실에 따른 불완전 연소 가스는 2단으로 설치된 저온 탈질촉매 표면을 미연탄소로 침적시켜 촉매의 탈질 효율을 급격히 저감시켰다. 활성 저하의 원인 분석을 위하여 XRD, EDX, BET, TGA, SEM 등 다양한 특성 분석을 실시하였다. 재생 방법으로 산 세척, 초음파 수 세척, 공기 중 소성의 방법을 적용한 결과, 공기분위기에서 $450^{\circ}C$로 2시간 소성하는 것이 최적조건 임을 밝혀내었다. 재생된 촉매는 2 cm ${\times}$ 2 cm ${\times}$ 10 cm(촉매 무게 10 g) Honeycomb 촉매 시료를 이용하여 활성을 측정한 결과 사용 전 촉매와 동일한 수준의 활성인 $180^{\circ}C$에서 NOx저감 효율 100%를 나타내었다.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2006년도 춘계임시총회 및 제27회 학술발표대회
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• pp.78-85
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• 2006

In textile industries, waste effluent containing zinc is generated during the manufacture of rayon yarn from the wood pulp or cotton linters. Due to the strict environmental regulations and the presence of toxic metallic and other constituents, the discharge of industrial effluents in the sewage or disposal of solid sludge as landfill is restricted. Before recycling of zinc as zinc sulphate solution to the spinning-bath of the rayon manufacturing plant the zinc sulphate solution must be free from calcium, which is deleterious to the process as gypsum precipitates with the increase in concentration and forms scale in the bath. In the present work an attempt has been made to develop a process following solvent extraction technique using thiophosphinic extractants, Cyanex 272 and 302 modified with isodecanol and diluted in kerosene to recover zinc from rayon effluent. Various process parameters viz. extraction of zinc from different concentration of solution, distribution ratio, selective extraction, O/A ratio on extraction and stripping from the loaded organic, complex formation in the organic phase etc. have been studied to see the feasibility of the process. The extractant Cyanex 302 has been found selective for the recovery of 99.99% of zinc from the effluent above equilibrium pH 3.4 maintaining the O/A ratio of 1/30 leaving all the calcium in the raffinate. It selectively extracted zinc in the form of complex $[R_{2}Zn.3RH]_{org}$ and retained all the calcium in the aqueous raffinate. The zinc from the loaded Cyanex 302 can be stripped with 10% sulphuric acid at even O/A ratio of 10 without affecting the stripping efficiency. The stripped solution thus obtained could be recycled in the spinning bath of the rayon plant. The raffinate obtained after the recovery of zinc could be disposed safely without affacting environment.

• 패션비즈니스
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• 제18권3호
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• pp.73-90
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• 2014

Paper, once known and used only as a medium for printing or handicrafts, is now being used in new fields including artistic clothing, and an environment-friendly material for fashion, while the functionality of its formative characteristics and esthetics have been newly highlighted. On this basis, this study performed a content analysis of paper couture and categorization of types of paper modeling techniques based on 904 paper couture submitted to paper fashion shows, exhibitions and contest exhibits from 2001 to 2013. Analysis results showed that paper textile types were most common at 86.64%, while techniques using laminating, bonding, overlapping or paper as-is represented 62.17%. Expressive techniques in which paper was cut or torn and attached to paper clothing was 11.62%, paper folding was 5.75%, drawing and coloring 4.65%, and finally, paper cutting was 2.65%. Meanwhile, among paper modeling techniques using paper yarn textiles, a paper weaving technique was 6.75%. Moreover, other techniques in which paper modeling techniques or subsidiary clothing was blended were 3.65%, and Dak peeling textiles were 1.33%. Paper paste moulding textiles types represented 1.44%, above all papier $m{\hat{a}}ch{\acute{e}}$ techniques of 0.55% and creasing and holding techniques were 0.88%. Paper is sufficient to express the artists' creativity as well as having qualities as an artistic medium, such as variability through combined use with other materials, variation in form, suitability for reuse of waste paper, and environmental friendliness. Also, various paper modeling techniques can be blended with textiles for a generalized technology that overcomes the limits of paper and textiles.

• 한국수산과학회지
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• 제25권3호
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• pp.205-218
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• 1992

미소조류의 응용연구 추세를 1970년을 기준으로 양분하여 조사하였다 전반기(1970년 이전)에는 배양한 미소조류 세포체 자체를 이용하기 위한 연구가 많다. 이 때에는 유용생물의 먹이, 식용단백질, 생물비료, 유기물 폐수처리 등의 분야를 주된 연구 대상으로 삼았다. 1970년 이후(후반기)에는 미소조류 세포체의 대량생산 방식을 탈피하여, 미소조류의 세포대사 특성물질 중 유용성분을 생산하기 위한 연구가 급격히 증가하고 있다. 즉, 비타민, 아미노산, 베타 카로틴, phycofluor, 약제성분, 생물활성물질, 수소가스 및 중수소 화학물질 등 단가가 매우 높은 천연순물질의 생산을 목표로 하여 연구력을 집중하는 추세이다. 국내의 관련 연구분야는 아직 초기단계에 있다고 판단된다. 미소조류 응용분야의 미래가능성으로 보아, 국내의 관련연구 수준을 시급히 향상시킬 필요가 있다. 이를 위해 국내에서 순수분리한 미소조류의 clonal culture를 관리하는 체계를 우선적으로 구축하여야 한다.

• 한국환경과학회지
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• 제15권1호
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• pp.33-43
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• 2006

Revetment Mattress/Filter is the porous structure filled fillers in meshed structure so that it cail use the fillers of various sizes and form various pores. The porous structure of the Mattress/Filter increases drainage so that it decreases the energy and erosion of flow therefore the tractive force is decreased and the erosion of revetment is mitigated. The filler of Mattress/Filter uses gravels, waste concretes and slags so that the surface is rough and the roughness coefficient increases and the increase of the roughness coefficient decreases flow velocity and tractive force. On the other hand Mattress/Filter and vegetation are combined so that the increase of roughness coefficient and flow velocity still more progress therefore the effect of decrease of tractive force is increased after a few months have passed since the Mattress/Filter is constructed so that the vegetation is developed and be stabilized. The vegetation channel of Mattress/Filter is set tip and the inspection comes into operation by varing flowrate and vegetation spacing to examine these characters of the Mattress/Filter The coefficient of flow velocity U/U*' is decreased exponentially as vegetation esity aH' or $\lambda$ is increased and the coefficient of friction f is increased as vegetation desity aH' is increased but decreased as the coefficient of flow velocity U/U*' is increased. The effective tractive force $F_0$ is decreased exponentially as the vegetation desity aH' is increased. From the inspection the results are obtained that the porous and vegetation structure of the revetment Mattress/Filter system increases the coefficient of friction of revetment so that flow velocity and effective are decreased therefore greatly contributes the stability of the revetment.

• Nuclear Engineering and Technology
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• 제34권1호
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• pp.42-59
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• 2002

In order to transmute long-lived radioactive nuclides such as transuranics(TRU), Tc-99, and I- l29 in LWR spent fuel, a preliminary conceptual design study has been performed for the accelerator driven subcritical reactor system, called HYPER(Hybrid Power Extraction Reactor) The core has a hybrid neutron energy spectrum: fast and thermal neutrons for the transmutation of TRU and fission products, respectively. TRU is loaded into the HYPER core as a TRU-Zr metal form because a metal type fuel has very good compatibility with the pyre- chemical process which retains the self-protection of transuranics at all times. On the other hand, Tc-99 and I-129 are loaded as pure technetium metal and sodium iodide, respectively. Pb-Bi is chosen as a primary coolant because Pb-Bi can be a good spallation target and produce a very hard neutron energy spectrum. As a result, the HYPER system does not have any independent spallation target system. 9Cr-2WVTa is used as a window material because an advanced ferritic/martensitic steel is known to have a good performance under a highly corrosive and radiation environment. The support ratios of the HYPER system are about 4∼5 for TRU, Tc-99, and I-129. Therefore, a radiologically clean nuclear power, i.e. zero net production of TRU, Tc-99 and I-129 can be achieved by combining 4 ∼5 LWRs with one HYPER system. In addition, the HYPER system, having good proliferation resistance and high nuclear waste transmutation capability, is believed to provide a breakthrough to the spent fuel problems the nuclear industry is faced with.

• 한국수소및신에너지학회논문집
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• 제30권3호
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• pp.282-288
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• 2019

When liquefied natural gas (LNG) is vaporized to form natural gas for industrial and household consumption, a tremendous amount of cold energy is transferred from LNG to seawater as a part of the phase-change process. This heat exchange loop is not only a waste of cold energy, but causes thermal pollution to coastal fishery areas by dumping the cold energy into the sea. This project describes an innovative new design for reclaiming cold energy for use by cold storage warehouses (operating in the 35 to $62^{\circ}C$ range). Conventionally, warehouse cooling is done by mechanical refrigeration systems that consume large amounts of electricity for the maintenance of low temperatures. Here, a closed loop LNG heat exchange system was designed (by simulator) to replace mechanical or vapor-compression refrigeration systems. The software PRO II with PROVISION V9.4 was used to simulate LNG cold energy, gas re-liquefaction, and the vaporized process under various conditions. The effects on sensible and latent heats from changes to the array type of heat exchangers have been investigated, as well as an examination of the optimum.

• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1540-1553
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• 2019

A nuclear power plant (NPP) is a highly complex system-of-systems as manifested through its internal systems interdependence. The negative impact of such interdependence was demonstrated through the 2011 Fukushima Daiichi nuclear disaster. As such, there is a critical need for new strategies to overcome the limitations of current risk assessment techniques (e.g. the use of static event and fault tree schemes), particularly through simulation of the nonlinear dynamic feedback mechanisms between the different NPP systems/components. As the first and key step towards developing an integrated NPP dynamic probabilistic risk assessment platform that can account for such feedback mechanisms, the current study adopts a system dynamics simulation approach to model the thermal dynamic processes in: the reactor core; the secondary coolant system; and the pressurized water reactor. The reactor core and secondary coolant system parameters used to develop system dynamics models are based on those of the Palo Verde Nuclear Generating Station. These three system dynamics models are subsequently validated, using results from published work, under different system perturbations including the change in reactivity, the steam valve coefficient, the primary coolant flow, and others. Moving forward, the developed system dynamics models can be integrated with other interacting processes within a NPP to form the basis of a dynamic system-level (systemic) risk assessment tool.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.395-408
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• 2018

Even after the Fukushima nuclear accident in 2011, the rate of production of electric energy using nuclear energy is increasing, but there is a great danger such as the radioactive waste produced when using nuclear power, the catastrophic accident of nuclear power plant, and connection with nuclear weapons. In particular, Cs present in the ionic form of alkaline elements has a long half-life (30.17 years) because it is readily absorbed by the organism and emits intense gamma rays, thus presenting a serious radiation hazard. Therefore, it must be completely removed before it can be released into the natural ecosystem, because it can adversely affect not only humans but also natural ecosystems. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. In addition, researches have been doing to synthesize magnetic materials with adsorbents such as HCF and PB, and it shows a great effect in the removal rate of Cs present in wastewater or the maximum Cs adsorption amount. In particular, when a magnetic material was applied, excellent results were obtained in which only Cs was selectively removed from other cations. However, new problems such as applicability in the sea where Cs is directly released, applicability in various pH ranges, and failure to preserve the magnetizing force possessed by the magnetic body have been found. However, researches using ferromagnetic field with stronger magnetic properties than those of magnetic bodies is considered to be insufficient. Therefore, it is considered that if the researches combining the ferromagnetic field with the magnetization ability and functional adsorbents more actively, the radioactive material Cs which adversely affects the natural ecosystem can be effectively removed.