• Journal of the Korean Wood Science and Technology
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• 제41권5호
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• pp.447-455
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• 2013

Hemicellulose extract obtained by pre-pulping extraction of woodchips, is very diluted acidic in nature. The major component responsible for this weak acidity is acetic acid, present in levels up to 5~10 g/L. Here, we report an exploratory study on the extract upgrading by reactive solvent extraction of acetic acid as well as ASPEN simulation. In this study, liquid-liquid equilibria for the ternary systems (water + acetic acid + ethyl acetate) were measured at the temperature of 298.15 K and 10 (pH = 2.02), 5 (pH = 2.17), and 1 (pH = 2.48) percent of acetic acid samples were used to carry out liquid-liquid extraction studies using ethyl acetate. In a one-stage batch experiment, 96.0% of acetic acid could be extracted for the solvent when the ratio of organic-to-aqueous phases is 4:1. For simulation results, they were used to estimate the interaction parameters between each of the three compounds of the systems studied for the NRTL and UNIQUAC models. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models.

• 자원리싸이클링
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• 제28권2호
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• pp.3-13
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• 2019

알루미늄은 지각 구성 원소 중 실리콘에 이어 두 번째로 풍부한 금속원소이다. 알루미늄은 가볍고, 전기전도도가 우수하고, 내식성이 우수하지만 산소와의 친화력이 강한 특성을 가지고 있다. 그러나 알루미늄의 1차 지금을 제조하기 위해서는 다량의 에너지를 소비한다. 한편 알루미늄 스크랩을 리사이클링하면 1차 지금 생산과 비교하여 에너지 및 환경부하를 저감할 수 있다. 그러나 알루미늄 스크랩 중의 불순물 제거가 곤란하여 재생되는 양은 한정되어 있다. 본 논문에서는 알루미나의 제조부터 스크랩 처리 및 용융까지의 알루미늄 생산 및 리사이클링 공정에 대하여 고찰하였다.

• Ocean Systems Engineering
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• 제13권1호
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• pp.79-95
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• 2023

An onshore dismantling yard is an important part in the supply chain of the offshore oil and gas decommissioning industry. However, despite having more than 500 offshore structures to be decommissioned in the Southeast Asia region, there are a very limited number of well-equipped dismantling yards to fully execute the onshore dismantling. Recent investigations discovered that shipbuilding and offshore structure fabrication yards are still potential options for upgrades to include dismantling. Despite the huge potential opportunities from upgrading to dismantling, research studies on this area are relatively scarce, and most past studies mainly focused on the North Sea region. To date, the potential opportunities of Southeast Asia and Malaysia yards to develop onshore dismantling capability are still unclear. The aim of this study is to identify the criteria to develop a technical preparedness checklist to evaluate an onshore dismantling yard; consequently, this will assist with assessing and bridging the gaps and identify the opportunity of developing an onshore dismantling yard in Southeast Asia region. Requirements for onshore dismantling and related rules and regulations have been investigated and summarized in the form of checklist. Findings from this study can help local oil and gas operators to pursue more local solutions and resilient supply chain performance.

• 유기물자원화
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• 제28권4호
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• pp.43-52
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• 2020

멤브레인을 이용한 기체 분리 기술이 발전함에 따라 분리 과정을 설명하기 위해 다양한 수학적 모델을 개발하고 적용해 왔다. 본 연구에서는 셀룰로오스 아세테이트(CA) 중공사 분리막을 제조하여 실험에 사용하였다. 메탄, 질소, 산소 및 이산화탄소 순수가스를 이용하여 투과도를 측정하고, 향류 흐름 모델(Counter-current model)을 적용하여 실험데이터와 비교/해석하였다. CA 막에 대한 이산화탄소와 메탄의 투과도는 각각 25.82 GPU와 0.65 GPU로 나타났다. CO2/CH4 선택도는 39.7이었다. 순수가스 테스트 후 세 가지 모의 혼합가스에 대한 분리 테스트를 수행하였으며, 다양한 stage-cut 조건에서 투과된 가스의 농도를 측정하였다. 실험으로 얻은 데이터를 향류 흐름 모델로 비교한 결과 상당히 일치하는 것으로 나타났으며, CA 멤브레인 모듈을 사용한 바이오가스 분리를 수학적 모델로 구현할 수 있었다. 또한 유한차분법(FDM)을 적용하여 멤브레인에서 바이오가스의 분리 거동을 유추할 수 있었다. 향후 향류 흐름 모델은 바이오가스 분리 공정을 위한 모델로서 활용 가능할 것으로 기대된다.

• 에너지공학
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• 제16권2호
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• pp.83-92
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• 2007

석유자원 고갈에 따른 대체에너지 개발의 필요성과 더불어 온실가스인 $CO_{2}$ 저감 등 높은 환경개선 효과로 인하여 새로운 청정연료로 바이오매스로부터 제조되는 BTL(Biomass to Liquid)-디젤에 대한 관심이 유럽을 중심으로 크게 증가하고 있다. 본 논문에서는 BTL-디젤 기술 개발 현황 및 BTL 공정의 세부 공정기술들을 조사하였다. BTL 공정은 바이오매스 전처리 및 가스화, 합성가스 정제, F-T(Fischer-Tropsch) 합성 및 upgrading 공정 등으로 나눌 수 있으며, BTL 만의 차별적 기술로 합성가스 제조를 위한 가스화 공정과 함성가스 조성 조절을 포함하는 BTL 공정에 최적화된 F-T 합성 촉매 개발이 매우 중요하다. 대표적인 BTL 기술로 독일의 Choren 사는 Carbo-V 가스화 기술을 개발하여 세계 최초로 BTL 공정 상업화를 이루었으며, 네덜란드의 ECN은 tar와 BTX를 제거하기 위한 독자적인 OLGA 기술을 개발하여 가스화 시스템과 연계한 공정을 개발하였다. 또한 미국과 일본 등 많은 나라에서 경쟁적으로 기술개발을 재촉하고 있는 상황이다. 국내의 경우 이에 대한 연구는 전무하나 국내 에너지 안보를 위한 에너지 Mix 정책과 지구온난화 등 환경문제에 대응하기 위하여 BTL 기술 개발은 매우 중요한 의미를 가질 수 있으므로 독창적 기술의 선점이 매우 중요할 것으로 판단된다.

• 한국실내디자인학회논문집
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• 제38호
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• pp.3-13
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• 2003

Now that 15 years have passed since its introduction to 4 year college in Korea and we have 51 majors in the field of Intoner design established at 47 universities as of 2003, we are in the position to seek the improvement of its educational qualify. With a view to provide data for the setup of proper educational purpose, it has classified their divisions(departments) according to their major names and belonged colleges of the universities and considered their geographical distributions, groupings of curriculum, their framing and features of a standard curriculum. 1)Divisions of the universities where the major of interior design belongs are divided into three categories of design division (design 8t arts, arts), home economics division (home economics, natural science) and architectural division. For the development of the major, universities to which circumstances permit are recommended to establish an independent college of interior design following the . cases in the US. 2) Geographical preponderance of interior design major on Seoul and Gyeongsang Province is desired to be improved. 3) Curriculum of interior design, which is classified into introduction, history of interior design, theory of interior design, design of interior space, digital technology, design elements of inner space, technology of interior design, behavior of environmental psychology, design management and other subjects, was made into a table by divisions. To sum up, curriculum of interior design concentrates on basic design theory throughout all divisions. In connection with the selection of division by high school-graduates or their parents, design division is recommended for those who desire to major in design elements and design management, home economics division for those who desire to major in space design and behavior of environmental psychology and architectural division for those who desire to major in Interior space design, interior design technology and regulations. 4) This research can contribute to the settlement of desirable curriculum for the interior design education, thus upgrading the education level of the major in Korea.

• Environmental Engineering Research
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• 제22권1호
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• pp.19-30
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• 2017

Direct catalysis of vapors from vacuum pyrolysis of biomass was performed on MCM-41 to investigate the effects of operating parameters including catalyzing temperature, catalyzing bed height and system pressure on the organic yields. Optimization of organic phase yield was further conducted by employing response surface methodology. The statistical analysis showed that operating parameters have significant effects on the organic phase yield. The organic phase yield first increases and then decreases as catalyzing temperature and catalyzing bed height increase, and decreases as system pressure increases. The optimal conditions for the maximum organic phase yield were obtained at catalyzing temperature of $502.7^{\circ}C$, catalyzing bed height of 2.74 cm and system pressure of 6.83 kPa, the organic phase yield amounts to 15.84% which is quite close to the predicted value 16.19%. The H/C, O/C molar ratios (dry basis), density, pH value, kinematic viscosity and high heat value of the organic phase obtained at optimal conditions were 1.287, 0.174, $0.98g/cm^3$, 5.12, $5.87mm^2/s$ and 33.08 MJ/kg, respectively. Organic product compositions were examined using gas chromatography/mass spectrometry and the analysis showed that the content of oxygenated aromatics in organic phase had decreased and hydrocarbons had increased, and the hydrocarbons in organic phase were mainly aliphatic hydrocarbons. Besides, thermo-gravimetric analysis of the MCM-41 zeolite was conducted within air atmosphere and the results showed that when the catalyst continuously works over 100 min, the index of physicochemical properties of bio-oil decreases gradually from 1.15 to 0.45, suggesting that the refined bio-oil significantly deteriorates. Meanwhile, the coke deposition of catalyst increases from 4.97% to 14.81%, which suggests that the catalytic activity significantly decreases till the catalyst completely looses its activity.

• 한국지반공학회논문집
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• 제29권6호
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• pp.77-86
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• 2013

연약지반위에 성토를 할 경우 초기 비배수 상태 뿐만 아니라 압밀 과정 중에도 큰 변형이 발생한다. 기존의 미소변형률 이론은 변형률이 작고 초기의 기하학적인 형상이 변형과정 동안 변하지 않는다고 가정하므로 큰 변형이 유발되는 지반공학 문제들을 해석하기 위해서는 대변형 해석을 수행하여야 한다. 힘평형 방정식과 유체 연속방정식이 결합된 압밀지배 방정식을 Updated-Lagrangian 형태로 수식화하고, Jaumann stress rate을 이용하여 역학적 구성관계를 표현하였다. 그리고 Nagtegaal이 제안한 회전을 고려한 구성관계를 적용하여 Newton의 반복과정을 통한 해의 수렴성과 정확도를 향상시켰다. 개발된 대변형 압밀해석 프로그램을 검증하기 위하여 켄틸레버보와 이차원 압밀문제를 해석하였다. 수치해석 결과는 큰 변형률과 기하학적 회전을 포함하는 대변형 문제를 효과적으로 묘사할 수 있음을 보여주었다. 기존의 미소변형이론에 근거한 유한요소 프로그램은 제안한 방법을 통하여 대변형 해석 프로그램으로 용이하게 전환될 수 있다.

• 환경영향평가
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• 제21권6호
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• pp.903-916
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• 2012

We need to use aesthetic landscape assessment(ALA) as the means of riparian buffer zone(RBZ) management. This study verified the political validity of designation policy of RBZ and land purchase policy. The purpose of this study was to propose RBZ landscape management strategies through ALA of RBZ in Gyeongan Stream for the better attractive and healthy riparian landscapes. The natural type landscape units(LUs) covered 40.9% of the entire area and the cultivated land type LUs covered 20.58%. Landscape assessment consisted of landscape quality and landscape integration assessment. The criteria for assessing landscape quality(LQ) were naturalness, interest, uniqueness, and landscape function. LQ was ranked into five grades using a matrix. The landscape integration assessment consisted of an inner integration assessment in each LU and outer integration assessment among LUs. To review the propriety of designating the riparian area and the riparian ecological belt, differences in ecological appraisal and aesthetic valuation were reviewed through a t-test, Oneway ANOVA, and logistic analysis. The results of ALA, 29.15% of the entire area scored at grade 1 in LQ, while 31.95% scored at grade 5, indicating that grade 5 areas occupied a high share. Surveyed areas were divided into designated RBZ and undesignated RBZ. Results indicated that designated RBZ scored grade 1 in LQ took up 33.2% of the total, significantly higher than the 23.3% taken up by undesignated RBZ. When examined according to buffer distance, grade 1 areas within 50m took up 50.2% of the total area, lower than the 32.7% at buffer distances of 500m-1km. Results indicated a 1% statistically significant difference. Accordingly, analysis was undertaken for the expansion of designation of the riparian area and the selection of appropriate land for formation of a riparian ecological belt, and was designated at priority 1 and 2 for land purchase. This study can also contribute to the formation of a riverine eco-belt through discovery of design factors for upgrading the ecology, aesthetics, and landscape of the riparian area and application in determining land purchase priorities.

• 수산해양교육연구
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• 제17권2호
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• pp.193-208
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• 2005

The object of this study is to provide a framework of increasing the effectiveness of the R&D planning of experts in fisheries and the education of students with the theoretical background and analytical skills through the adoption of technology roadmapping process in the marine production industry. The study was conducted by fact-finding surveys and the response content for surveys obtained from each expert advisor in the field of fisheries and maritime affairs such as fishery industries, some government organizations and research institutes including the Ministry of Maritime Affairs and Fisheries (MOMAF), National Fisheries Research and Development Institute (NFRDI) and fisheries-related universities was analyzed. The major implementation tasks to effectively achieve the basic goals of technology roadmap for short and middle-term research and development in the fisheries production field are as follows: 1. Research in order to achieve the realization of community-based resource management fisheries or fishermen-oriented co-management fisheries with paradigm shift in fisheries management. 2. Research in order to derive the construction of cost reducing and manpower saving systems in fishery-related science, technology and engineering. 3. Research in order to create the high value-added fisheries products with a focus on the upgrading of processing, freezing and refrigerating facilities, the reduction of logistics costs and the minimization of distribution steps. 4. Research in order to achieve the realization and development of environmental-friendly fisheries and internationally competitive fisheries through restructuring the entire fishing industries, in particular, small-scale fisheries. 5. Research in order to achieve the effective utilization of fisheries resources with a new creation of clean and living marine environment by fisherman under the balanced management and protection of marine living resources and fishing grounds.