• 제목/요약/키워드: Synthesis

검색결과 20,327건 처리시간 0.053초

연구용 결정 성장 (Crystal Growth for the Research Purpose)

  • 허남정
    • 한국자기학회지
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    • 제21권3호
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    • pp.108-115
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    • 2011
  • 이 글에서는 응집물질물리 실험에 필수적인 소규모의 연구용 고순도 시료 제작에 있어 기본적인 사항들을 살펴본다. 연구자들이 쉽게 접근할 수 있는 시료 제작법들을 중심으로 제작 과정과 유의점등을 소개하려 한다. 가장 흔히 사용되는 고상소결법으로 부터 시작하여 다양한 환경에서 다결정 및 단결정 제작에 필수적인 석영관을 이용한 시료 제작에 대해 설명하고 단결정 제작의 기초와 다양한 단결정 성장법에 대해서도 전반적으로 소개하여 시료 제작을 처음 접하는 연구자들의 이해를 돕도록 한다.

원자력 이용 고체산화물 고온전기분해 수소 및 합성가스 생산시스템의 열역학적 효율 분석 연구 (A Study on Thermodynamic Efficiency for HTSE Hydrogen and Synthesis Gas Production System using Nuclear Plant)

  • 윤덕주;고재화
    • 한국수소및신에너지학회논문집
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    • 제20권5호
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    • pp.416-423
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    • 2009
  • High-temperature steam electrolysis (HTSE) using solid oxide cell is a challenging method for highly efficient large-scale hydrogen production as a reversible process of solid oxide fuel cell (SOFC). The overall efficiency of the HTSE hydrogen and synthesis gas production system was analyzed thermo-electrochemically. A thermo-electrochemical model for the hydrogen and synthesis gas production system with solid oxide electrolysis cell (SOEC) and very high temperature gas-cooled reactor (VHTR) was established. Sensitivity analyses with regard to the system were performed to investigate the quantitative effects of key parameters on the overall efficiency of the production system. The overall efficiency with SOEC and VHTR was expected to reach a maximum of 58% for the hydrogen production system and to 62% for synthesis gas production system by improving electrical efficiency, steam utilization rate, waste heat recovery rate, electrolysis efficiency, and thermal efficiency. Therefore, overall efficiency of the synthesis production system has higher efficiency than that of the hydrogen production system.

유전자 알고리즘을 이용한 분할 버스 아키텍처의 상위 수준 합성 (A genetic-algorithm-based high-level synthesis for partitioned bus architecture)

  • 김용주;최기영
    • 전자공학회논문지C
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    • 제34C권3호
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    • pp.1-10
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    • 1997
  • We present an approach to high-level synthesis for a specific target architecture-partitioned bus architecture. In this approach, we have specific goals of minimizing data transfer length and number of buses in addition to common synthesis goals such as minimizing number of control steps and satisfying given resource constraint. Minimizing data transfer length and number of buses can be very important design goals in the era of deep submicron technology in which interconnection delay and area dominate total delay and area of the chip to be designed. in partitioned bus architecture, to get optimal solution satisfying all the goals, partitioning of operation nodes among segments and ordering of segments as well as scheduling and allocation/binding must be considered concurrently. Those additional goals may impose much more complexity on the existing high-level synthesis problem. To cope with this increased complexity and get reasonable results, we have employed two ideas in ur synthesis approach-extension of the target architecture to alleviate bus requirement for data transfer and adoption of genetic algorithm as a principal methodology for design space exploration. Experimental results show that our approach is a promising high-level synthesis mehtodology for partitioned bus architecture.

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환경성 유해요인이 유전물질과 세포활성에 미치는 영향 V. CHO세포에서 세포주기에 따라 돌연변이원에 의해 유발된 DNA회복합성에 미치는 DNA중합효소의 역할 (Environmental Toxic Agents on Genetic Material and Cellular Ativity V. The Roles of DNA Polymerases on Mutagen-Induced DNA Repair Synthesis in Relation to Cell Cycle in Chinese Hamster Ovary Cells)

  • 엄경일;김춘광;신은주;문용석;이천복
    • 한국환경성돌연변이발암원학회지
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    • 제9권1호
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    • pp.23-32
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    • 1989
  • Chinese hamster ovary (CHO)-K1 cells echibited a differential sensitivity in the process of DNA repair synthesis induced by ethyl methanesulfonate (EMS) or bleomycin (BLM) in relation to cell cycle. Two assays were employed in this study: alkaline elution and unscheduled DNA synthesis. The post-treat-ment with aphidicolin (APC), an inhibitor of DNA polymerase alpha, inhibited DNA repair synthesis induced by EMS in G2 phase, while APC did not show any effect on BLM-induced DNA repair synthesis in all phases. On the other hands, the 2', 3'-dideoxythymidine (ddTTP), an inhibitor of DNA polymerase beta, inhibited DNA repair synthesis induced by EMS or BLM in both of G1 and G2 phases. These results suggested that the involvement of DNA polymerase alpha and beta in DNA repair was dependent on cell stage or used chemical agent.

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분석과 종합문제의 분류 기준에 대한 연구 -러시아 구세프의 수학교과서를 중심으로- (A study on the classification standards of the problem of analysis and synthesis)

  • 권영인;서보억
    • 한국수학교육학회지시리즈E:수학교육논문집
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    • 제20권2호
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    • pp.231-248
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    • 2006
  • 수학적인 사고에는 여러가지 유형이 있는데 그 중에서 가장 기본이 되는 사고유형이 분석과 종합이다. 이러한 사고유형을 담고 있는 분석과 종합문제는 수학문제의 가장 중요한 근간이라고 할 수 있다. 이러한 분석과 종합문제에 대한 체계적인 분석과 구체적인 논의를 위해 러시아의 구세프 교수가 편찬한 수학교과서를 중심으로 이러한 두 가지 유형의 문제에 대한 분석을 실시한다. 또한, 역사적으로 제시되어진 분석과 종합에 대한 다양한 문헌연구를 통해 두 가지 사고유형의 분류에 대한 기본적인 기준을 설정하고, 이를 바탕으로 분석문제와 종합문제에 대한 구체적인 분류기준을 제시하고자 한다.

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전역좌표계에 근거한 부분구조합성법과 국부좌표계에 근거한 부분구조합성법의 비교 (Comparison of Substructure Synthesis Methods based on Global and Local Coordinates)

  • 곽문규;나성수;배병찬
    • 한국소음진동공학회논문집
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    • 제16권7호
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    • pp.712-719
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    • 2006
  • This paper is concerned with the comparison of substructure synthesis methods based on global and local coordinates. The substructure synthesis methods based on the global coordinates were first proposed for the dynamic analysis of complex structure and the substructure synthesis method based on the local coordinates was proposed to solve the dynamic problem of tree-like structure. However, the conceptual difference between two methods in solving the dynamic problem has never been explained. In this paper, a structure consisting of two beams is considered to show the conceptual difference of two methods. The dynamic formulation shows the characteristics and differences of two methods explicitly. The procedure for choosing proper substructure modes in each method is also explained in detail. In addition, the advantage of the substructure synthesis method based on the local coordinate system is discussed based on the numerical example. Numerical examples show how two methods are applied to the addressed problem.

Regulation of Chlorophyll-Protein Complex Formation and Assembly in Wheat Thylakoid Membrane

  • Guseinova, I.M.;Suleimanov, S.Y.;Aliev, J.A.
    • BMB Reports
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    • 제34권6호
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    • pp.496-501
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    • 2001
  • Lincomycin, an inhibitor of plastid protein synthesis, was found to block the synthesis of apoprotein P700 with a molecular mass of 72 kDa and the assembly of the Chl a-protein of PS I. Synthesis of the polypeptides of 48, 43.5, and 32 kDa of the PS II complex is also suppressed. This process is accompanied by the disappearance of the PS Two reaction center Chl a at 683 nm, and of the PS One reaction center Chl a at 690, 696, and 705 nm on the fourth derivative of the absorption spectra at 77K. Lincomycin does not affect the synthesis of LHC subunits. It increases the content of the two main Chl forms of LHC at 648 nm (Chl b) and 676 nm (Chl a). The low-temperature fluorescence ratio F736/F685 is also increased. However, the effect of cycloheximide (an inhibitor of cytoplasmic protein synthesis) leads to the reduction of polypeptides of the light-harvesting Chl a/b-protein complex in the range of 29.5-22 kDa. Under these conditions, the relative amount of Chl b and the F736/ F685 fluorescence ratio decrease significantly. This is obviously the result of blocking the LHC I and LHC II synthesis. At the same time rifampicin and actinomycin D (inhibitors which block transcription in chloroplast and nuclear genome, respectively) inessentially affect the characteristics of these complexes.

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Utilization of Substrate for the In vitro Lipid Synthesis in the Adipose Tissue of Hanwoo Steers

  • Song, M.K.;Sohn, H.J.;Hong, S.K.;Kim, H.C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권11호
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    • pp.1560-1563
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    • 2001
  • An ability to utilize the substrates (acetate, glucose and lactate) in the lipid synthesis was measured in vitro with the adipose tissues of 4 locations (subcutaneous, SUBC; intramuscular, INTR; tail and kidney, KIDN) in 12 Hanwoo (Korean native cattle) steers (26 and 28 months of ages, mean body weight 638.6 kg). The rates of lipid synthesis from acetate were higher than those from glucose in SUBC and ITRA adipose tissues, respectively. In contrast, the rates of lipid synthesis from glucose were higher than those from acetate in the adipose tissues of tail and KIDN, respectively. Lactate utilization was lowest in all the locations while that of acetate or glucose had the different trends of utilization in the lipogenesis. The rate of lipid synthesis from acetate was highest in the SUBC adipose tissue but was lowest in the KIDN while that from glucose was also higher in the SUBC adipose tissue than in the other tissue locations. The rate of lipid synthesis from lactate, however, was highest in the tail adipose tissue among the locations.

Short-Cut Pathway to Synthesize Cellulose of Encysting Acanthamoeba

  • Moon, Eun-Kyung;Kong, Hyun-Hee
    • Parasites, Hosts and Diseases
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    • 제50권4호
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    • pp.361-364
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    • 2012
  • The mature cyst of Acanthamoeba is highly resistant to various antibiotics and therapeutic agents. Cyst wall of Acanthamoeba are composed of cellulose, acid-resistant proteins, lipids, and unidentified materials. Because cellulose is one of the primary components of the inner cyst wall, cellulose synthesis is essential to the process of cyst formation in Acanthamoeba. In this study, we hypothesized the key and short-step process in synthesis of cellulose from glycogen in encysting Acanthamoeba castellanii, and confirmed it by comparing the expression pattern of enzymes involving glycogenolysis and cellulose synthesis. The genes of 3 enzymes, glycogen phosphorylase, UDP-glucose pyrophosphorylase, and cellulose synthase, which are involved in the cellulose synthesis, were expressed high at the 1st and 2nd day of encystation. However, the phosphoglucomutase that facilitates the interconversion of glucose 1-phosphate and glucose 6-phosphate expressed low during encystation. This report identified the short-cut pathway of cellulose synthesis required for construction of the cyst wall during the encystation process in Acanthamoeba. This study provides important information to understand cyst wall formation in encysting Acanthamoeba.

부분 구조 모드 합성법 및 유전 전략 최적화 기법을 이용한 비부합 절점을 가진 구조물의 구조변경 (Structural Dynamics Modification of Structures Having Non-Conforming Nodes Using Component Mode Synthesis and Evolution Strategies Optimization Technique)

  • 이준호;정의일;박윤식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.651-659
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    • 2002
  • Component Mode Synthesis (CMS) is a dynamic substructuring technique to get an approximate eigensolutions of large degree-of-freedom structures divisible into several components. But, In practice. most of large structures are modeled by different teams of engineers. and their respective finite element models often require different mesh resolutions. As a result, the finite element substructure models can be non-conforming and/or incompatible. In this work, A hybrid version of component mode synthesis using a localized lagrange multiplier to treat the non-conforming mesh problem was derived. Evolution Strategies (ESs) is a stochastic numerical optimization technique and has shown a robust performance for solving deterministic problems. An ESs conducts its search by processing a population of solutions for an optimization problem based on principles from natural evolution. An optimization example for raising the first natural frequency of a plate structure using beam stiffeners was presented using hybrid component mode synthesis and robust evolution strategies (RES) optimization technique. In the example. the design variables are the positions and lengths of beam stiffeners.

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