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Development of Graphene Nanocomposite Membrane Using Layer-by-layer Technique for Desalination (다층박막적층법을 이용한 담수화용 그래핀 나노복합체 분리막 개발)

  • Yu, Hye-Weon;Song, Jun-Ho;Kim, Chang-Min;Yang, Euntae;Kim, In S.
    • Membrane Journal
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    • v.28 no.1
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    • pp.75-82
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    • 2018
  • Forward osmosis (FO) desalination system has been highlighted to improve the energy efficiency and drive down the carbon footprint of current reverse osmosis (RO) desalination technology. To improve the trade-off between water flux and salt rejection of thin film composite (TFC) desalination membrane, thin film nanocomposite membranes (TFN), in which nanomaterials as a filler are embeded within a polymeric matrix, are being explored to tailor the separation performance and add new functionality to membranes for water purification applications. The objective of this article is to develop a graphene nanocomposite membrane with high performance of water selective permeability (high water flux, high salt rejection, and low reverse solute diffusion) as a next-generation FO desalination membrane. For advances in fabrication of graphene oxide (GO) membranes, layer-by-layer (LBL) technique was used to control the desirable structure, alignment, and chemical functionality that can lead to ultrahigh-permeability membranes due to highly selective transport of water molecules. In this study, the GO nanocomposite membrane fabricated by LBL dip coating method showed high water flux ($J_w/{\Delta}{\pi}=2.51LMH/bar$), water selectivity ($J_w/J_s=8.3L/g$), and salt rejection (99.5%) as well as high stability in aqueous solution and under FO operation condition.

The Change of Tissue Lipid Levels and Fatty Acid Compositions by Alloxan-induced Diabetes in Rats (Alloxan 유도 당뇨성 흰쥐에서 조직 중 지질 수준 및 지방산 조성 변화에 관한 연구)

  • Lee, Joon-Ho;Jun, In-Nyo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.8
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    • pp.1273-1278
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    • 2004
  • The change of tissue lipid levels and fatty acid compositions in alloxan-induced diabetes was studied in rats (SD, male) in order to examine the pathway of diabetic complications. Rats were injected with alloxan 20 mg/kg BW or 40 mg/kg BW to induce diabetes. In rats injected with alloxan (40 mg/kg BW), the body weight was significantly decreased, food intake and liver weight per 100 g (BW) were significantly increased, compared with other groups. The blood glucose levels were apparently elevated as about 2 times in rats injected with alloxan (40 mg/kg BW) than the other groups. The concentrations of serum total cholesterol, triglyceride and HDL-cholesterol were not significantly different among the groups. However, the levels of serum triglyceride tended to increase according to amount of alloxan injected. Liver cholesterol levels were significantly decreased in rats injected with alloxan (40 mg/kg BW) compared with other groups, but triglyceride levels of those were not significantly different among groups. Concerning the fatty acid compositions of serum, liver, kidney, spleen phosphatidylcholine, the percentage of linoleic acid in rats injected with alloxan (40 mg/kg BW) was significantly increased, while that of arachidonic acid was significantly decreased compared with the other groups. Therefore, the ratios of arachidonic/linoleic acid in tissue phosphatidylcholine tended to be low in rats injected with alloxan (40 mg/kg BW) and especially significant low levels were found in serum and spleen. Thus, it was suggested that insulin deficiency can affect on fatty acid biosynthesis and induce diabetic complications.

Evidence Suggesting that the Deposition of Pigments into Yolks is Independent of Egg Production: Enhanced Pigmentation of Yolks by Feeding Hens with Canthaxanthin Biosynthesized by Microbials (난황 내 색소의 축적은 산란율과 무관함을 제시하는 증거: 균체가 생성하는 Canthaxanthin의 급여에 의해 강화된 난황의 착색)

  • Kim, Ji-Min;Kim, Jong-Jin;Lee, Shi-Hyoung;Choi, Yang-Ho
    • Korean Journal of Poultry Science
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    • v.38 no.3
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    • pp.239-245
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    • 2011
  • Pigments in the diet affect yolk colors. Due to variations in both the bioavailability of pigments in chickens and their amounts occurring in the feed ingredients, concern about egg quality arises in terms of yolk color. In this study, the effects of pigments, produced through cell culture in the laboratory, on yolk colors were determined for 4 weeks in laying hens receiving one of the 6 dietary treatments: control diets containing 1) no synthetic pigments (CON); 2) canthaxanthin (4 ppm) purchased from BASF (BASF); 3) cultured cells so that the diet had canthaxanthin at 4 ppm (CX); 4) cultured cells so that the diet had lycopene at 30 ppm (LP); 5) canthaxanthin (4 ppm) that was purified from cultured cells (SPCX); or 6) lycopene (30 ppm) that was purified from cultured cells. Relation between deposition of pigments into yolks and egg production was also tested. Yolk color of eggs from chickens fed dietary CX was significantly enhanced, which was slightly but significantly below that of BASF. Results from other treatments were lower than those of CX. Deposit rates of pigments into yolks were: BASF > CX > SPCX > LP > SPLP. The amounts of pigments, with the exception of SPLP, in feed were not changed during the storage for 4 weeks at $25^{\circ}C$. Egg production rates varied among treatments during the initial phase of the study but became relatively uniform at the later stage, except for CON and LP groups. The results of the present study indicate that the deposition of pigments into yolks is independent of egg production.

ON THE OCEANOGRAPHIC CONDITIONS OF OYSTER FARMAING AREA NEAR CHUNGMU (충무부근 굴 양식어장의 환경에 관하여)

  • LIM Du Byung;CHO Chang Hwan;KWON Woo Sup
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.8 no.2
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    • pp.61-67
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    • 1975
  • Oceanographic conditions of the coastal water around Chungmu, one of the most important oyster farming areas in Korea, were studied from May to November in 1974 to find out the environmental influence to oyster farming. Six localities, Goseong Bay, Jaran Bay, off Saryangdo, Hansilpo, Tong-yeong Bay and Juklimpo were selected for monthly oceanographic observation and biological sampling. Flood current running westward brings saline water from the south-east and ebb current brings the low salinity water of Jinju Bay into this area. The waters in Juklimpo, Hansilpo and Tong-yeong Bay are slightly cooler and more saline than the waters in Goseong Bay, Jaran Bay and off Saryangdo. The amount of dissolved oxygen is lowest in September and Hansilpo has the least oxygen during summer. Silicate content is lower in waters of Tong-yeong Bay, Juklimpo and off Saryangdo than those of Goseong Bay, Hansilpo and Jaran Bay. Suspended matter in this area ranges from 7.4 to 16.6 mg/l and scarce in Jaran Bay, Juklimpo and off Saryangdo. Chlorophyll a shows large seasonal variation and local fluctuation. Composition of phyto-plankton reveals the difference between the waters of Goseong Bay, Jaran Bay and off Saryangdo and the waters of Hansilpo, Tong-yeong Bay and Juklimpo. The growth of oyster was good in Juklimpo, Tong-yeong Bay and Goseong Bay and worst in Hansilpo. The highest mortality was observed $82\%$ in the waters off Saryangdo.

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태양계의 물: 기원과 진화

  • Choe, Byeon-Gak;Choe, Hye-Rim
    • 한국지구과학회:학술대회논문집
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    • 2005.09a
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    • pp.3-8
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    • 2005
  • 지구는 현재 태양계에서 액체 상태의 물이 표면에 존재하는 유일한 천체이다. 하지만, 고체 또는 기체 상태의 물은 태양계의 다른 행성이나, 위성, 소행성, 혜성 등에도 풍부하게 존재하고 있다. 풍부한 액체 상태의 물은 지구 표면에서 일어나고 있는 기후의 변화, 해류의 이동, 퇴적 및 침식 작용, 화산활동과 같은 여러 지구과학적 현상에 밀접하게 관여하고 있을 뿐 아니라 생명의 탄생과 진화에도 매우 중요한 역할을 하였다. 현재 지구 표면에 액체 상태의 물이 존재할 수 있는 이유는 태양으로부터의 거리, 지구의 조성 및 크기 등과 관련된 지구 표면의 물리-화학적 조건이 액체 상태의 물이 존재할 수 있는 조건과 일치하고 있기 때문이다. 이와는 달리 지구보다 태양에 더 가깝게 위치하고 있고, 두터운 이산화탄소 대기를 갖고 있어 표면의 온도가 매우 높은 금성의 경우 H2O는 기체 상태로 존재하며, 지구보다 더 멀리 떨어져 있고 희박한 대기를 갖고 있는 화성의 경우에는 현재 H2O가 고체 즉 얼음의 형태로 존재한다. 태양계를 탄생시킨 태양계 성운에서는 압력이 너무 낮아 액체 상태의 물이 존재할 수 없으며, 고온에서는 기체 상태로 매우 낮은 저온에서는 얼음의 형태, 또는 함수 광물 내에 포함되어 존재할 수 있다. 지구와 같은 규모의 행성은 비교적 중력이 작아 태양계 성운의 기체를 거의 끌어들이지 못했다. 따라서 현재 지구에 존재하는 물은 대부분은 고체 상태로 지구에 집적되었을 것이다. 하지만 지구가 탄생한 위치에서 초기 태양계의 온도는 얼음이 형성되기에는 너무 높았기 때문에 좀 더 먼 곳에서(현재의 목성 위치보다 바깥쪽)에서 생성된 얼음 즉, 혜성이 태양계 안쪽으로 들어와 지구에 물을 공급했거나 함수광물을 포함하고 있는 소행성(예를 들어 CI chondrites와 같은 조성의)이 물을 가져왔을 것으로 생각되고 있다.서의 활성화는 어미 변환과 관련된 영역이라기보다는 산출시 관련되는 articulation, motor coordinate관련 영역으로 추정되고, 측두엽의 활성화는 형태소, 의미 관련 지식의 data base로 추정된다. 또한 우반구 전두엽 부분에서 관찰된 활성화는 억제관련 영역으로 짐작된다.러한 동물실험이 그 기초를 제공해 줄 수 있을 것이다. 또한 행동성향 및 기억의 종류에 따른 약물효과의 차이는 기억과 관련된 질병인 알츠하이머 환자에 있어 개개인에게 맞는 적절한 특징적인 치료약물이 존재할 것이라는 가능성을 제공해줄 뿐만 아니라 학습과 기억력 증진 효과를 기대해 볼 수 있을 것이라고 생각된다. 및 지역산업발전의 기획${\sim}$조정기구로서, 선진국의 지역발전기구(Regional Development Agency : RDA)인 지역전략산업기획단이 2002년도부터 산업자원부와 9개 시도에 의해 설립되어 지역네트워크의 활성화와 클러스터의 형성 촉진을 하게 되었고 2004년도에는 13개시도로 확대${\sim}$운영되고 있고, 지역특화사업(H/W)과 지역산업기술개발과제(S/W)와 함께 패케지 형태로 지원되며, 주요역할은 크게 지역산업의 정책기획 분야와 평가관리, 지역혁신역량 조사 및 DB구축 등으로 구분된다. 그중에서도 권역별, 지역별, 지역산업진흥사업 육성과 중장기 산업발전계획을 수립하기 위하여 지역혁신역량을 바탕으로 한 지역 Technology Road Map(TRM)작성사업은 전국공통의 1단계 사업으로 실시 ?榮쨉?, 2005년 3월 기준으로 9개 지역(강원, 대전, 충남, 충북, 경북, 울산, 전남, 전북, 제주) 26개 산업분야를 대상으로 23개가 완료된 상황이다. 이를 근거로 한 지역정책과 R&D 과제 및 필요 인프라의 도출이 체계적으로 구축되어 지역산업 발전을 위한

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Development of an Assembly-type Liquid Level Control Experimental Equipment and a Hands-on Activity Task for Vocational High School 'Chemical Process Maintenance Operation' Subject (특성화고 '화학공정유지운영' 교과를 위한 조립형 액위제어 실험장치 및 체험활동과제 개발)

  • Jung, Eun-Suk;Lee, Kyung Taek
    • 대한공업교육학회지
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    • v.45 no.2
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    • pp.1-20
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    • 2020
  • The purpose of this study is to develop an assembly-type liquid level control experimental equipment and a hands-on activity task that can be applied to the class so that students studying the chemical industry can easily understand the liquid level control. For this purpose, the content elements related to liquid level control in the chemical industry practice course of the 2015 revised curriculum was analyzed, a hands-on activity task with an assembly-type liquid level control experimental equipment was and developed. And then, expert verification was also performed and the hands-on activity task was applied to 19 students of S meister high school. The results obtained through this are as follows. First, the existing completion-type liquid level control experimental equipment was explored, and based on this, a new assembly-type liquid level control experimental equipment that can be assembled by students and used for practices was designed and manufactured. Second. by analyzing the contents of the NCS-based 'Chemical Process Maintenance Operation' practical course of the 2015 revised curriculum, learning contents related to level control were extracted. Among the contents related to the level control, the practice with understanding the process flow chart, manufacturing the level control experimental equipment, measuring the flow rate, and checking the level control phenomenon were conducted with the assembly-type liquid level control experimental equipment to systematically learn the level control.

Feasibility of Analyzing Soil Organic Carbon Fractions using Mid-Infrared Spectroscopy (중적외선분광분석법을 이용한 토양 유기 탄소 분획 분석)

  • Hong, Seung-Gil;Shin, JoungDu;Park, Kwang-Lai;Lee, Sang-Beom;Kim, Jinho;Kim, Seok-Cheol;Shiedung, Henning;Amelung, Wulf
    • Journal of the Korea Organic Resources Recycling Association
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    • v.23 no.3
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    • pp.85-92
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    • 2015
  • For concerning the climate change issues, the carbon sequestration and importance of soil organic matter are receiving high attention. To evaluate carbon sequestration in soil is important to determine the soil organic carbon (SOC) fractions such as WESOC (Water extractable soil organic carbon), and $CO_2$ emission by soil microbial respiration. However, the analyses for those contents are time-consuming procedure. There were studied the feasibility of MIRS (Mid-Infrared Spectroscopy), which has short analysis time for determining the WESOC and an incubated carbon in this study. Oven-dried soils at $100^{\circ}C$ and $350^{\circ}C$ were scanned with MIRS and compared with the chemically analyzed WESOC and cumulative carbon dioxide generated during 30, 60, 90, and 120 days of incubation periods, respectively. It was observed that an optimized determination coefficient was 0.6937 between WESOC and untreated soil processed by spectrum vector normalization (SNV) and 0.8933 between cumulative $CO_2$ from 30 days incubation and soil dried at $350^{\circ}C$ after subtracting air-dried soil processed by 1st derivatives. Therefore, it was shown that Quantification of soil organic carbon fractions was possibility to be analyzed by using MIRS.

Analysis of Consistency and Accuracy for the Finite Difference Scheme of a Multi-Region Model Equation (다영역 모델 방정식의 유한차분계가 갖는 일관성과 정화성 분석)

  • 이덕주
    • Journal of Korea Soil Environment Society
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    • v.5 no.1
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    • pp.3-12
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    • 2000
  • The multi-region model, to describe preferential flow, is an equation representing solute transport in soils by dividing soil into numerous pore groups and using the hydraulic properties of the soil. As the model partial differential equation (PDE) is solved numerically with finite difference methods. a modified equivalent partial differential equation(MEPDE) of the partial differential equation of the multi-region model is derived to analyze the accuracy and consistency of the solution of the model PDE and the Von Neumann method is used to analyze the stability of the finite difference scheme. The evaluation obtained from the MEPDE indicated that the finite difference scheme was found to be consistent with the model PDE and had the second order accuracy The stability analysis is performed to analyze the model PDE with the amplification ratio and the phase lag using the Von Neumann method. The amplification ratio of the finite difference scheme gave non-dissipative results with various Peclet numbers and yielded the most high values as the Peclet number was one. The phase lag showed that the frequency component of the finite difference scheme lagged the true solution. From the result of the stability analysis for the model PDE, it is analyzed that the model domain should be discretized in the range of Pe < 1.0 and Cr < 2.0 to obtain the more accurate solution.

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Development of an Average Green Time Estimation Model for Proper Evaluation of Traffic Actuated Operation (감응식 신호운영의 평가를 위한 평균녹색시간 추정모형 개발)

  • KIM, Jin Tae;CHANG, Myungsoon;SON, Bongsoo;DOH, Tcheol Woong
    • Journal of Korean Society of Transportation
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    • v.20 no.3
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    • pp.159-168
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    • 2002
  • The Highway Capacity Manual(HCM) suggests estimating the average green time for the performance evaluation of the traffic actuated operation and Provides the average green time estimation model. However, the model provides with much room for improvements. This document proposes a new analytical model that overcomes the shortage of the HCM model. The average green times estimated by the HCM model and the proposed model were compared. A computer program using the proposed model was coded for the study, while the ACT348 program was used for the implementation of the HCM model Through the comparison study based on the 1,196 hypothetical simulation data surrogating field data, it was found that the average green times estimated by the proposed model yields much nicer one-to-one linear relationship to the simulation results than the ones from the HCM model in both exclusive-only and shared-permitted cases. The R2 values of the proposed and the HCM models with those cases are 0.90 and 0.56, and 0.86 and 0.57, respectively.

Effects of Acidification on Physical and Organoleptic Properties of Soybeans (산절임이 콩의 물리적, 관능적 특성에 미치는 영향)

  • 여경은;최희숙;김동원;김주숙;김우정
    • The Korean Journal of Food And Nutrition
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    • v.16 no.4
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    • pp.410-416
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    • 2003
  • Three varieties of soybean were acidified by soaking in two kinds of vinegar which were persimmon vinegar and brewed vinegar. Chemical properties of soaking solution and physical and organoleptic properties of soybean during soaking at room temperature for 8 days were studied. The soybeans were acidified in vinegar solution at room temperature for 8 days. The results showed that soybean weight was rapidly increased until first two days and then gradually increased thereafter. Increase in total acidity and sugar concentration and decrease in pH of vinegar solution were also measured during initial soaking stage. The changes in pH and acidity were more significant in brewed vinegar than those in persimmon vinegar, The L values of persimmon vinegar solution after soaking the soybean were relatively lower than that of brewed vinegar. The a values of the vinegar solution used for black beans were increased while that of the vinegar solution used for white beans were decreased, The flavor and texture of acidified bean in persimmon vinegar were more soft and less benny than those acidified in vinegar. However sourness of the acidified beans in persimmon vinegar was much softer higher to those values of brewed vinegar.