• Title/Summary/Keyword: growth reaction

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Chemical Reaction of Pentacene Growth on Hybrid Type Insulator by Annealing Temperature (하이브리드 타입 절연막 위에서 열처리 온도에 따른 펜타센 생성과 관련된 화학반응)

  • Oh Teresa
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.2 s.344
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    • pp.13-17
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    • 2006
  • Pentacene channel for organic thin film transistor was deposited on the SiOC film by thermal evaporation. The growth of pentacene is related with the Diels-Alder reaction and the nucleophilic reaction by the thermal induction. The surface is an important factor to control the recursive Diels-Alder reaction for growing of pentacene on SiOC far The terminal C=C double bond of pentacene molecule was broken easily as a result of attack of the nucleophilic reagents on the surface of SiOC film. The nucleophilic reaction can be accelerated by increasing temperature on surface, and it maks pentacene to grow hardly on the SiOC film with a flow rate ratio of $O_2/(BTMSM+O_2)=0.5$ due to its inorganic property. The nucleophlic reaction mechanism is $SN_2(bimolecular nucleophilic substitution)$ type.

Growth of Nano- and Microstructured Indium Nitride Crystals by the Reaction of Indium Oxide with Ammonia

  • Jung, Woo-Sik;Ra, Choon-Sup;Min, Bong-Ki
    • Bulletin of the Korean Chemical Society
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    • v.26 no.9
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    • pp.1354-1358
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    • 2005
  • Nano- and microstructured indium nitride crystals were synthesized by the reaction of indium oxide ($In_2O_3$) powder and its pellet with ammonia in the temperature range 580-700 ${^{\circ}C}$. The degree of nitridation of $In_2O_3$ to InN was very sensitive to the nitridation temperature. The formation of zero- to three-dimensional structured InN crystals demonstrated that $In_2O_3$ is nitridated to InN via two dominant parallel routes (solid ($In_2O_3$)-to-solid (InN) and gas ($In_2O$)-to-solid (InN)). The growth of InN crystals with such various morphologies was explained by the vapor-solid (VS) mechanism where the degree of supersaturation of In vapor determines the growth morphology and the vapor was mainly by the reaction of $In_2O$ with ammonia and partially by sublimation of solid InN. The pellet method was proven to be useful to obtain homogeneous InN nanowires.

Crystal Growing of NaX type Zeolite

  • Ha, Jong-Pil;Seo, Dong-Nam;Kim, Seong-Yong;Jung, Mi-Jeong;Moon, In-Ho;Cho, Sang-Joon;Park, Hyun-Min;Kim, Ik-Jin
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1999.06a
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    • pp.351-360
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    • 1999
  • A large NaX type zeolite crystal of a uniform particle size of 20${\mu}{\textrm}{m}$ are grown with various H2O content by hydrothermal reaction and added seed crystal (2~3 ${\mu}{\textrm}{m}$) to reactant solution as a function of different adding seed levels from 3 to 15 %. The result that increased purity of NaX zeolite above 95% and homogeneity of crystal size by increasing adding seed levels, also decreased crystallization time. It was explained that adding seed to synthesis solution leaded out increase of surface area of physical contact reaction and directed growth of seed crystal, so more rapid consumption of reaction gel as increase seeding levels.

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Growth mechanism of InP and InP/ZnS synthesis using colloidal synthesis (반응 용기법을 이용한 InP/ZnS 양자점 합성과정에서 InP 코어의 성장기구)

  • Seo, Han wook;Jeong, Da-woon;Lee, Bin;Hyun, Seoung kyun;Kim, Bum Sung
    • Journal of Powder Materials
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    • v.24 no.1
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    • pp.6-10
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    • 2017
  • This study investigates the main growth mechanism of InP during InP/ZnS reaction of quantum dots (QDs). The size of the InP core, considering a synthesis time of 1-30 min, increased from the initial 2.56 nm to 3.97 nm. As a result of applying the proposed particle growth model, the migration mechanism, with time index 7, was found to be the main reaction. In addition, after the removal of unreacted In and P precursors from bath, further InP growth (of up to 4.19 nm (5%)), was observed when ZnS was added. The full width at half maximum (FWHM) of the synthesized InP/ZnS quantum dots was found to be relatively uniform, measuring about 59 nm. However, kinetic growth mechanism provides limited information for InP / ZnS core shell QDs, because the surface state of InP changes with reaction time. Further study is necessary, in order to clearly determine the kinetic growth mechanism of InP / ZnS core shell QDs.

Monoclonal Antibody Refolding and Assembly: Protein Disulfide Isomerase Reaction Kinetics

  • Park, Sun-Ho;Ryu, Dewey D.Y.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.2
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    • pp.59-63
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    • 2003
  • The protein disulfide isomerase (PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody (Mab) refolding and assembly which accompanies disulfide bend formation. The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb in-termediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant fur a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

Monoclonal Antibody Refolding and Assembly: Protein Disulfide Isomerase Reaction Kinetics

  • Park, Sun-Ho;Ryu, Dewey D.Y.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.1 no.1
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    • pp.13-17
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    • 1996
  • The protein disulfide isomerase(PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody(MAb) refolding and assembly which accompanies disulfide bond formation The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb intermediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant for a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

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The Effect of Electrical Stimulation on Bacterial Growth (전기자극이 세균성장에 미치는 영향)

  • Park Young-Han;Kim Jin-Sang;Park Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.6 no.1
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    • pp.109-119
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    • 1994
  • The study was carried out to investigate the change of bacterial growth in vitro according to polarity, current intensity and time, to prepare the basic data for electrotherapy and clinical research. The Gram positive Staphylococcus aureus and Gram negative Escherichia coli 1mm infect wound were cultured in Trypticase Soy Brath and Trypticase Soy Agar. The results were as followings. 1. The current stimulated group was changed in bacterial growth according to polarity, current intensity and time respectively. 2. The bacteriolytic effect revealed in the anode but the inhibitory effect of bacterial growth revealed in the cathode. 3. The lumber of E. coli reduced after 6-hours but the numbers of S. aureus reduced after 2 hours in Trypticase Soy Brath. 4. The anode showed acid reaction and cathode showed alkaline reaction in Trypticase Soy Agar.

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New Self-Directed Growth Mechanism of Molecular Lines across the Dimer Rows on H-terminated Si(001) Surface

  • Choi, Jin-Ho;Cho, Jun-Hyung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.301-301
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    • 2011
  • We present theoretical investigations of the self-assembled growth of one-dimensional (1D) molecular lines directed across the dimer rows on the H-terminated Si(001) surface [1]. Based on density-functional theory calculations, a new growth mechanism of the 1D acetylacetone line is proposed [2], which involves the radical chain reaction initiated at two dangling-bond sites on one side of two adjacent Si dimers. It is also enabled that, if an H-free Si dimer were employed as the initial reaction site, a 1D acetylacetone line can grow along the dimer row. Our findings represent the first insight into the growth of 1D molecular lines not only across but also along the dimer rows on the H-terminated Si(001) surface.

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THIN FILM GROWTH AND SURFACE REACTION ON H-TERMINATED SILICON SURFACE

  • Yasuda, Yukio;Zaima, Shigeaki
    • Journal of the Korean institute of surface engineering
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    • v.29 no.5
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    • pp.407-414
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    • 1996
  • We have investigated the effects of H atoms on thin film growth processes and surface reactions. In the oxidation of Si, Si surfaces are passivated against the $O_2$ adsorption by terminating dangling bonds with H atoms. Moreover, the existence of Si-H bonds on Si(100) surfaces enhances the structural relaxation of Si-O-Si bonds due to a charge transfer from Si-Si back bonds. In the heteroepitaxial growth of a Si/Ge/Si(100) system, H atoms suppress the segregation of Ge atoms into Si overlayers since the exchange of Ge atoms with Si atoms bound with H must be accompanied with breaking of Si-H bonds. However, 3-dimensional island growth is also promoted by atomic H irradiation, which is considered to result from the suppression of surface migration of adsorbed reaction species and from the lowering of step energies by the H termination of dangling bonds.

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Effect of Electrochemical Redox Reaction on Growth and Metabolism of Saccharomyces cerevisiae as an Environmental Factor

  • Na, Byung-Kwan;Hwang, Tae-Sik;Lee, Sung-Hun;Ahn, Dae-Hee;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.17 no.3
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    • pp.445-453
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    • 2007
  • The effect of an electrochemically generated oxidation-reduction potential and electric pulse on ethanol production and growth of Saccharomyces cerevisiae ATCC 26603 was experimented and compared with effects of electron mediators (neutral red, benzyl viologen, and thionine), chemical oxidants (hydrogen peroxide and hypochlorite), chemical reductants (sulfite and nitrite), oxygen, and hydrogen. The oxidation (anodic) and reduction (cathodic) potential and electric pulse activated ethanol production and growth, and changed the total soluble protein pattern of the test strain. Neutral red electrochemically reduced activated ethanol production and growth of the test strain, but benzyl viologen and thionine did not. Nitrite inhibited ethanol production but did not influence growth of the test strain. Hydrogen peroxide, hypochlorite, and sulfite did not influence ethanol production and growth of the test strain. Hydrogen and oxygen also did not influence the growth and ethanol production. It shows that the test strain may perceive electrochemically generated oxidation-reduction potential and electric pulse as an environmental factor.