• Title/Summary/Keyword: synthetic solution

검색결과 611건 처리시간 0.025초

MLE type MBBR을 이용한 페놀화합물 함유폐수의 처리특성 (Characteristics of Phenolic Wastewater Treatment using Moving Bed Biofilm Reactor in the MLE Process)

  • 김문호;오성모;배윤선;박철휘
    • 상하수도학회지
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    • 제21권5호
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    • pp.521-529
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    • 2007
  • Nutrient removal from synthetic wastewater was investigated using a MLE (Modified-Ludzack Ettinger) type MBBR (Moving Bed Biofilm Reactor), with different phenol ($C_6H_5OH$) concentrations, in order to determine the inhibition effects of phenol on biological nutrient removal and the biodegradation of phenolic wastewater. The wastewater was prepared by mixing a solution of molasses with known amounts of phenol and nutrients. The experiments were conducted in a lab-scale MLE type MBBR, operated with four different phenol concentrations (0, 67, 100 and 168mg/L) in the synthetic feed. Throughout the experiments, the ratio of the phenolic COD concentration to the total COD was varied from 0 to 1. Throughout batch test, the SNR (Specific Nitrification Rate) and SDNR (Specific Denitrification Rate) were significantly influenced by changes of the phenol concentration. Phenol was inhibitory to the nitrification/denitrification process, and showed greater inhibition with higher initial phenol concentrations. The SNR observed with 0, 67, 100 and 168mg phenol/L were very different like 10.12, 6.95, 1.51 and $0.35mg\;NH_{3^-}N/gMLVSS$ hr, respectively. Similarly, the SDNR observed at 0, 67, 100 and 168mg phenol/L were different like 0.322, 0.143, 0.049and 0.006mgN/gMLVSS day, respectively.

(2-(2,6-디클로로페닐)아미노)페닐 아세트산나트륨의 합성 (The Synthesis of Sodium (2-(2,6-Dichlorophenyl)Amino)Phenyl Acetate)

  • 황선원;정노희;남기대
    • 공업화학
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    • 제5권3호
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    • pp.413-418
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    • 1994
  • (2-(2, 6-디클로로페닐)아미노)페닐 아세트산나트륨의 합성단계를 줄이고 각 단계별 합성수율을 향상시켰다. 합성은 4단계로 하였으며 출발물질은 2,6-디클로로아닐린과 모노브로모벤젠을 사용하였다. 첫단계인 Ullmann반응은 구리촉매를 3회 분할 첨가하여 80%의 수율로 진행시켰고, 아실화와 프리델-크라프트 반응도 효율적으로 단순화하였다. 최종 반응생성물인 디클로페낙은 클라이젠 용액을 사용하여 제3단계에서 얻은 1-(2, 6-디클로로페닐)-2-인돌리논을 가수분해함으로써 97%의 수율로 얻었다.

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A106 GrB강 용접부의 염수중 부식피로특성 (Corrosion Fatigue Characteristics of A106-GrB Steel Weldments in NaC1 solution)

  • 김철한
    • 한국생산제조학회지
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    • 제6권3호
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    • pp.65-72
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    • 1997
  • The horizontal corrosion fatigue tester has been developed for investigating environmental strength. Using this tester, we investigated about corrosion fatigue caracteristics for A106-Gr B steel weldments in 3.5% synthetic seawater and room temperature. Considered parameter is only frequency of 1, 3 and 5Hz.. and Corrosion fatigue crack length was measured by DC potential difference method. From the results, we could find that the horizontal corrosion fatigue tester could be well applied to estimation of fatigue strength. and, In case of 5Hz., corrosion fatigue crack growth pate of A106-Gr B steel weldment was transgranular, and of 1 and 3Hz. showed that transgranular and interfranular was mixed. Also, Material constants of corrosion fatigue crack growth estimated in each frequency were C=9.33$\times$$10^{-9}$ and m=2.93 in 1Hz., C=9.77$\times$$10^{-10}$ and m=3.47 in 3Hz., C=1.02$\times$$10^{-10}$ and m=4.05 in 5Hz

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SYNTHETIC DEVELOPMENT OF NEW 1$\beta$-SUBSTITUTED CARBAPENEMS

  • Nagao, Yoshimitsu
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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    • pp.34-35
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    • 1993
  • The Development of new asymmetric induction methods useful for syntheses of biologically active natural products and drugs, using C4-chiral 1,3-th-iazolidine-2-thiones, has been a recent focus of interest. 1-8) The present account describes the significance of particular heterocycles in the synthetic development of new 1${\beta}$-substituted carbapenems. A fungal metabolite, (+)-thienamycin (1) has attracted one's attention as a hopeful candidate for new-generation antibiotic drugs because of its strong antimicrobial activities and wide antimicrobial spectra due to the extensive inhibition against various ${\beta}$-lactamases. However, it has been serious problems toward a practically useful drug that (+)-thienamycin is fairly labile in the solution and can be metabolized by renal dehydropept- idase-I (DHP-I). Recently, a Merck Sharp & Dohme research group exploited a non-natural ${\beta}$-lactam, imipenem (2) which has been appeared in the drug market as the first carbapenem-type antibiotic drug. 9) However 2 must be used with a DHP-I inhibitor, cilastatin sodium (3).9) Thus, a 1,${\beta}$-methyl- carbapenem derivative 4 has been disclosed by the same group. 10) It seems to be more hopeful candidate as a new-generation antibiotic because it can directly resist against metabolism by the renal DHP-1 without an enzyme inhibitor 3. 10)

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Graphene Oxide as a Novel Nanoplatform for Direct Hybridization of Graphene-SnO2

  • Park, Hun;Han, Tae Hee
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3269-3273
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    • 2013
  • Graphene oxide (GO) has been of particular interest because it provides unique properties due to its high surface area, chemical functionality and ease of mass production. GO is produced by chemical exfoliation of graphite and is decorated with oxygen-containing groups such as phenol hydroxyl, epoxide groups and ionizable carboxylic acid groups. Due to the presence of those functional groups, GO can be utilized as a novel platform for hybrid nanocomposites in chemical synthetic approaches. In this work, GO-$SnO_2$ nanocomposites have been prepared through the spontaneous formation of molecular hybrids. When $SnO_2$ precursor solution and GO suspension were simply mixed, $Sn^{2+}$ was spontaneously formed into $SnO_2$ nanoparticles upon the deoxygenation of GO. Through further chemical reduction by adding hydrazine, reduced GO-$SnO_2$ hybrid was finally created. Our investigation for the electrocapacitive properties of hybrid electrode showed the enhanced performance (389 F/g), compared with rGO-only electrode (241 F/g). Our approach offers a scalable, robust synthetic route to prepare graphene-based nanocomposites for supercapacitor electrode via spontaneous hybridization.

2점지지계류를 활용한 심해 부유체의 다점지지계류 개념설계 (Conceptual Design of Deep-sea Multi-Point Mooring by using Two-Point Mooring)

  • 박인규;김경무
    • 대한조선학회논문집
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    • 제45권4호
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    • pp.462-467
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    • 2008
  • In this paper, we investigated the design method of mooring system in ultra deep sea and carried out the conceptual design for offshore West Africa oil field in ultra deep sea of 3000 meters. Recently, it was feasible to design and install the offshore floating structures in deep sea of up to 2000 meters. Due to the simplicity, two-point mooring design is fully utilized. Force-excursion curves are throughly examined to find out the feasibility of various combinations of mooring lines. Free length and pretension effects are discussed. It is found that composite materials including synthetic fiber rope may be good solution for ultra deep sea mooring design.

한국 해군의 함대합성훈련(FST) 적용 연구 (A Study on the FST Applications of Korean Navy)

  • 전태보;박창호
    • 한국시뮬레이션학회논문지
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    • 제25권3호
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    • pp.29-39
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    • 2016
  • 전투력 향상을 위해서는 전장환경에 부합하는 훈련체계의 구축 및 적응 노력이 무엇보다도 중요하다. 본 연구에서는 시뮬레이션 기반의 훈련 체계인 FST (Fleet Synthetic Training)에 대한 고찰 및 한국 해군 측면의 분석을 수행하고 정책적인 제안을 도출하였다. 먼저, FST의 개념 및 현재 우리 해군의 훈련체계에 대한 전반적인 실태를 고찰하였다. 객관적인 전략 및 제안의 도출을 위하여 우리 군의 내부 역량과 FST 측면의 환경에 대한 SWOT 분석을 수행하였다. 한국 해군이 나아갈 방안으로 현재 진행중인 함대들의 통합전술재박훈련 체계를 중심으로 단계적이고 점진적인 접근을 통한 FST의 체계 정착이 제시되었다.

층상 이중 수산화물 나노물질의 성장 제어기술 연구동향 (Recent Development in Fabrication and Control of Layered-Double Hydroxide Nanostructures)

  • 전찬우;박일규
    • 한국분말재료학회지
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    • 제25권6호
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    • pp.514-522
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    • 2018
  • Layered-double hydroxide (LDH)-based nanostructures offer the two-fold advantage of being active catalysts with incredibly large specific surface areas. As such, they have been studied extensively over the last decade and applied in roles as diverse as light source, catalyst, energy storage mechanism, absorber, and anion exchanger. They exhibit a unique lamellar structure consisting of a wide variety of combinations of metal cations and various anions, which determine their physical and chemical performances, and make them a popular research topic. Many reviewed papers deal with these unique properties, synthetic methods, and applications. Most of them, however, are focused on the form-factor of nanopowder, as well as on the control of morphologies via one-step synthetic methods. LDH nanostructures need to be easy to control and fabricate on rigid substrates such as metals, semiconductors, oxides, and insulators, to facilitate more viable applications of these nanostructures to various solid-state devices. In this review, we explore ways to grow and control the various LDH nanostructures on rigid substrates.

Image-to-Image Translation with GAN for Synthetic Data Augmentation in Plant Disease Datasets

  • Nazki, Haseeb;Lee, Jaehwan;Yoon, Sook;Park, Dong Sun
    • 스마트미디어저널
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    • 제8권2호
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    • pp.46-57
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    • 2019
  • In recent research, deep learning-based methods have achieved state-of-the-art performance in various computer vision tasks. However, these methods are commonly supervised, and require huge amounts of annotated data to train. Acquisition of data demands an additional costly effort, particularly for the tasks where it becomes challenging to obtain large amounts of data considering the time constraints and the requirement of professional human diligence. In this paper, we present a data level synthetic sampling solution to learn from small and imbalanced data sets using Generative Adversarial Networks (GANs). The reason for using GANs are the challenges posed in various fields to manage with the small datasets and fluctuating amounts of samples per class. As a result, we present an approach that can improve learning with respect to data distributions, reducing the partiality introduced by class imbalance and hence shifting the classification decision boundary towards more accurate results. Our novel method is demonstrated on a small dataset of 2789 tomato plant disease images, highly corrupted with class imbalance in 9 disease categories. Moreover, we evaluate our results in terms of different metrics and compare the quality of these results for distinct classes.

The theranostic roles of extracellular vesicles in pregnancy disorders

  • Saadeldin, Islam M.;Tanga, Bereket Molla;Bang, Seonggyu;Fang, Xun;Yoon, Ki-Young;Lee, Sanghoon;Cho, Jongki
    • 한국동물생명공학회지
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    • 제37권1호
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    • pp.2-12
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    • 2022
  • Extracellular vesicles (EVs) are nanovesicles that carry bioactive cargoes of proteins, lipids, mRNAs, and miRNAs between living cells. Their role in cellular communication has gained the attention of several research reports globally in the last decade. EVs are critically involved in sperm functions, oocyte functions, fertilization, embryonic development, and pregnancy. The review summarizes the state-of-the-art of EVs research in the diagnostic and therapeutic (theranostic) potentials of the EVs during the pregnancy that might provide a solution for gestational disturbances such as implantation failure, maternal health problems, gestational diabetes, and preeclampsia. EVs can be found in all biological fluids of the fetus and the mother and would provide a non-invasive and excellent tool for diagnostic purposes. Moreover, we provide the current efforts in manufacturing and designing targeted therapeutics using synthetic and semi-synthetic nanovesicles mimicking the natural EVs for efficient drug delivery during pregnancy.