• Title/Summary/Keyword: synthesis methods

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Comparison of Component Mode Synthesis and Substructure Synthesis Methods (구분모드합성법과 부분구조합성법의 비교)

  • Kwak, Moon-K.;Na, Sung-Soo;Bae, Byung-Chan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.1348-1353
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    • 2006
  • This paper is concerned with the comparison of component mode synthesis md substructure synthesis methods. Those two methods were developed for the dynamic analysis of complex structure. However, the difference between two methods in solving the dynamic problem has never been explained. In this paper, a structure consisting of two beams is considered for the application of two methods. The dynamic formulation shows the characteristics and differences of two methods. The procedure for choosing proper substructure modes in each method is explained in detail. In addition, the advantage of the substructure synthesis method is discussed based on the numerical example. Numerical examples show how two methods are applied to the addressed problem.

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Recent Developments in Synthesis of Colloidal Quantum Dots (콜로이드 양자점 합성의 다양한 연구 개발 동향)

  • Jung, Jae-Yong;Hong, Jong-Pal;Kim, Young-Kuk
    • Journal of Powder Materials
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    • v.25 no.4
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    • pp.346-354
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    • 2018
  • Over the last decade, the study of the synthesis of semiconductor colloidal quantum dots has progressed at a tremendous rate. Colloidal quantum dots, which possess unique spectral-luminescent characteristics, are of great interest in the development of novel materials and devices, which are promising for use in various fields. Several studies have been carried out on hot injection synthesis methods. However, these methods have been found to be unsuitable for large-capacity synthesis. Therefore, this review paper introduces synthesis methods other than the hot injection synthesis method, to synthesize quantum dots with excellent optical properties, through continuous synthesis and large capacity synthesis. In addition, examples of the application of synthesized colloid quantum dots in displays, solar cells, and bio industries are provided.

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

  • Kwak, Moon-K.;Na, Sung-Soo;Bae, Byung-Chan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.7 s.112
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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.

Combinatorial Solid Phase Peptide Synthesis and Bioassays

  • Shin, Dong-Sik;Kim, Do-Hyun;Chung, Woo-Jae;Lee, Yoon-Sik
    • BMB Reports
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    • v.38 no.5
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    • pp.517-525
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    • 2005
  • Solid phase peptide synthesis method, which was introduced by Merrifield in 1963, has spawned the concept of combinatorial chemistry. In this review, we summarize the present technologies of solid phase peptide synthesis (SPPS) that are related to combinatorial chemistry. The conventional methods of peptide library synthesis on polymer support are parallel synthesis, split and mix synthesis and reagent mixture synthesis. Combining surface chemistry with the recent technology of microelectronic semiconductor fabrication system, the peptide microarray synthesis methods on a planar solid support are developed, which leads to spatially addressable peptide library. There are two kinds of peptide microarray synthesis methodologies: pre-synthesized peptide immobilization onto a glass or membrane substrate and in situ peptide synthesis by a photolithography or the SPOT method. This review also discusses the application of peptide libraries for high-throughput bioassays, for example, peptide ligand screening for antibody or cell signaling, enzyme substrate and inhibitor screening as well as other applications.

Cyclic Peptides as Therapeutic Agents and Biochemical Tools

  • Joo, Sang-Hoon
    • Biomolecules & Therapeutics
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    • v.20 no.1
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    • pp.19-26
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    • 2012
  • There are many cyclic peptides with diverse biological activities, such as antibacterial activity, immunosuppressive activity, and anti-tumor activity, and so on. Encouraged by natural cyclic peptides with biological activity, efforts have been made to develop cyclic peptides with both genetic and synthetic methods. The genetic methods include phage display, intein-based cyclic peptides, and mRNA display. The synthetic methods involve individual synthesis, parallel synthesis, as well as split-and-pool synthesis. Recent development of cyclic peptide library based on split-and-pool synthesis allows on-bead screening, in-solution screening, and microarray screening of cyclic peptides for biological activity. Cyclic peptides will be useful as receptor agonist/antagonist, RNA binding molecule, enzyme inhibitor and so on, and more cyclic peptides will emerge as therapeutic agents and biochemical tools.

Modal Analysis of Plate by Substructure Synthesis Method (부분구조합성법을 이용한 판의 모우드해석)

  • Jung, Jae-Hoon;Jee, Tae-Han;Park, Young-Pil
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.6
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    • pp.65-74
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    • 1994
  • Various substructure synthesis methods, such as component mode synthesis, building block analysis and reduced impedance method, are studied for the determination of vibration characteristics of plate problems. Comparisons are made for each methods in terms of accuracy and computational efficiency. Following conclusions are made from the results of computer simulations and experiments. i) The computation time of component mode synthesis is much shorter than that of whole structure analysis. The natural frequencies of lower modes obtained from component mode synthesis are almost same as those obtained from whole structure analysis, but in higher modes the differences between those two methods are increases. ii) The transfer function obtained from building block analysis is same as that obtained from the finite element method. iii) Same transfer functions can be obtained by the reduced impedance method. The computation time of reduced impedance mathod is shorter that that of general finite element method, but for the solutions in broad frequency band it requires long calculation time.

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Synthesis of 2-Aroyloxyacetophenones as Intermediates for Flavone Synthesis (Flavone의 합성 중간체인 2-Aroyloxyacetophenone류의 새로운 합성법)

  • Song, Gyu-Yong;Ahn, Byung-Zun
    • YAKHAK HOEJI
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    • v.38 no.1
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    • pp.1-5
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    • 1994
  • We have synthesized some 2-(2-benzyloxybenzoyloxy)-and 2-(2,6-dibenzyloxybenzoyloxy)-acetophenones as intermediates for flavone synthesis. The reaction of polyoxygenated 2-hydroxyacetophenones with 2-benzyloxybenzoic acid or 2,6-dibenzyloxybenzoic acid in the presence of dicyclohexylcarbodiimide and p-dimethylaminopyridine resulted in a good yield$(70{\sim}89%)$ of 2-(2-benzyloxybenzoyloxy)-acetophenones or 2-(2,6-dibenzyloxybenzoyloxy) acetophenones under milder conditions and in shorter time than the previous methods. This new methods using benzoic acids instead of benzoyl chlorides saves one reaction step of acid chlorination in comparision of the previous methods.

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A Study on the Vibration Characteristics of Weaving Machine Structure using Component Mode Synthesis (부분구조합성법을 이용한 제직기 구조물의 진도특성에 관한 연구)

  • 권상석;김병옥;전두환
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.535-539
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    • 2001
  • In these days. the finite element method(FEM) is a very common method for not only a simple vibration analysis but also the optimization of structures. Since the finite element model may contain thousands of degree of freedom, the eigensolutions require extreme computing power, which will result in a serious time-consuming problem. Thus, many researchers have challenged to find more improved modeling techniques and calculating methods to overcome such problems. The Guyan reduction method and the substructure synthesis method are typical examples of such methods. Of the substructure synthesis method, the component mode synthesis method (CMS) is widely used for dynamic analysis of structure. In this study. for the efficient analysis of jet loom structure. Component Mode Synthesis was carried out. The results of the finite element program developed are compared with those of the commercial package program ANSYS for the validation of the program. The results obtained by the program showed a good agreement with those of ANSYS. The program will be further refined and verified by test to yield more accurate results.

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A Brief review of Aragonite Precipitated Calcium Carbonate (PCC) Synthesis Methods and Its Applications

  • Ramakrishna, Chilakala;Thenepalli, Thriveni;Ahn, Ji Whan
    • Korean Chemical Engineering Research
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    • v.55 no.4
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    • pp.443-455
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    • 2017
  • This article provides an exclusive overview of the synthesized aragonite precipitated calcium carbonate and its applications in various fields. The last decade has seen a steady increase in the number of publications describing the synthesis, characterization and applications of calcium carbonate morphologies. Mainly, two kinds of processes have been developed for the synthesis of aragonite precipitated calcium carbonate under controlled temperature, concentrations and aging, and the final product is single-phase needle-like aragonite precipitated calcium carbonate formed. This review is mainly focused on the history of developed methods for synthesizing aragonite PCC, crystal growth mechanisms and carbonation kinetics. Carbonation is an economic, simple and ecofriendly process. Aragonite PCC is a new kind of functional filler in the paper and plastic industries, nowadays; aragonite PCC synthesis is the most exciting and important industrial application due to numerous attractive properties. This paper describes the aragonite PCC synthetic approaches and discusses some properties and applications.

Effects of Ball Milling for Elemental Powders on Ni-Al based Intermetallics Coating on Mild Steel through Induction Heating Process (Ni-Al계 금속간화합물의 고주파 연소합성코팅에 미치는 볼 밀링의 영향)

  • Lee, Han-Young;Park, Won-Kyu
    • Tribology and Lubricants
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    • v.33 no.6
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    • pp.296-302
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    • 2017
  • Ball milling of elemental powders in advance and using an induction heating system for intermetallic coatings are known to enhance the reactivity of combustion synthesis. In this work, the effects of simultaneously applying these two incentive methods on the properties of intermetallic coatings are studied. Ni-Al powder compacts ball-milled with three different ball-to-powder weight ratio mixtures are synthesized and coated on mild steel by combustion synthesis in an induction heating system. Consequently, similar to an electrical heating system, the positive effects of ball milling on the combustion synthesis are confirmed in the induction heating system. The enhancement in synthetic reactivity achieved by applying the two incentive methods at the same time is greater than that by applying each incentive method separately. In particular, the enhancement is remarkable at low reaction temperature. However, there are limitations to improving the reactivity by simultaneously applying the two incentive methods to the combustion synthesis, unlike the reaction temperature. The microstructure and hardness of the coating layer are both influenced by the ball-charging ratio employed in the ball-milling process.