• Title/Summary/Keyword: precursors

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Interaction of a Kinesin Superfamily Protein 1A (KIF1A) with Calmodulin

  • Seog, Dae-Hyun
    • Journal of Life Science
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    • v.12 no.2
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    • pp.43-46
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    • 2002
  • Kinesin Superfamily Protein 1A (KIF1A) is an anterograde monomeric motor transporting a subset of synaptic vesicle precursors and plays an important role in neuronal function and survival. Here, f have used the yeast two-hybrid system to identify the proteins that interacts with the tail region of KIF1A. Calmodulin was found to interact specifically with the tail region of KIF1A. Calmodulin regulates many diverse cellular functions by modulating the activity of the proteins that interact with it. KIF1A interacts with calmodulin in the yeast two-hybrid assay, which is proved by immunoprecipitation with calmodulin in brain fraction. These results indicate that KIF1A is associated with calmodulin, suggesting that calmodulin may be a key role in the regulation of anterograde transport of synaptic 1 vesicle precursors.

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Experiment on the Anomalous Animal Behaviors by Electric Field Effects for detecting Earthquake Precursors (지진전조현상 파악을 위한 전기장 효과에 의한 동물 이상 행동 실험)

  • 경재복;윤장근
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.57-64
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    • 2001
  • There are some previous reports that some animals such as rats and birds move in a large group and act abnormally to avoid the large earthquake. This study is to experimentally testify what relations exist between the anomalous animal behavior and electric field effect, which is reported due to the piezoelectric effects in a basement rock before earthquake occurrences. When electric field is applied to the whole bottom of the cage, they show nervous behaviors such as grooming, washing their faces, standing on legs or running around in panic to avoid the electric field. When more strong electric field is applied, they jump with shrieking and mount on the electric line. The rat shows more sensitive anomalous behavior than the bird. Even though the current to the experimental birds and rats is just a few $\mu$A, they react in various ways. The anomalous animal behaviors under the small ground electric field may have some relations to the actual phenomena before great earthquake. This kind of study is quite worthy for the understanding of earthquake precursors.

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Development of an Accident Sequence Precursor Methodology and its Application to Significant Accident Precursors

  • Jang, Seunghyun;Park, Sunghyun;Jae, Moosung
    • Nuclear Engineering and Technology
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    • v.49 no.2
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    • pp.313-326
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    • 2017
  • The systematic management of plant risk is crucial for enhancing the safety of nuclear power plants and for designing new nuclear power plants. Accident sequence precursor (ASP) analysis may be able to provide risk significance of operational experience by using probabilistic risk assessment to evaluate an operational event quantitatively in terms of its impact on core damage. In this study, an ASP methodology for two operation mode, full power and low power/shutdown operation, has been developed and applied to significant accident precursors that may occur during the operation of nuclear power plants. Two operational events, loss of feedwater and steam generator tube rupture, are identified as ASPs. Therefore, the ASP methodology developed in this study may contribute to identifying plant risk significance as well as to enhancing the safety of nuclear power plants by applying this methodology systematically.

Synthesis of novel disperse dyes derived from phthalimide containning diester groups and their dyeing properties

  • Choi, Jae-Hong;Choi, Jong-Yun;Lee, Hyun-Young;Kwon, Oh-Tak
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2009.03a
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    • pp.45-46
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    • 2009
  • In this study, 12 azo disperse dyes based on phthalimide were synthesized including their precursors. The chemical structures of the dyes and the corresponding precursors were analyzed by the GC-MASS, $^1H$ NMR spectra and elemental analysis. The dyeability on PET, such as step dyeing and build-up properties and color fastness were examined using conventional exhaust dyeing procedures.

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Mesodermal Patterning in Ascidian Embryos

  • 김길중
    • Proceedings of the Korean Society of Embryo Transfer Conference
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    • 2002.11a
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    • pp.37-42
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    • 2002
  • In ascidians, a primitive chordate, maternal cytoplasmic factors and inductive interactions are involved in the specification of cell fate in early embryos. The larval structure of ascidians is relatively simple, and the major mesodermal tissues of the tadpole larva are notochord, muscle and mesemchyme. Formation of muscle cells is a cell-autonomous process, and localized maternal macho-1 mRNA specify muscle fate in the posterior marginal zone of the early embryo. In contrast, inductive influence from endoderm precursors plays important roles in the specification of notochord and mesenchyme fates. FGF-Ras-MAPK signaling is involved in the induction of both tissues. The difference in responsiveness of the posterior mesenchyme and anterior notochord precursors is caused by the presence or absence of the posterior-vegetal egg cytoplasm, respectively. In these cases, directed signal may polarizes the responding cells and cause asymmetric cell divisions that operate in both the anterior and posterior regions.

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Low Temperature Synthesis of Willemite Powder (Willemite 분말의 저온합성)

  • Son, Se-Gu;Lee, Ji-Hyeon;Lee, Jeong-Mi;Kim, Young-Do
    • Journal of the Korean Ceramic Society
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    • v.45 no.7
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    • pp.401-404
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    • 2008
  • Willemite ($Zn_2SiO_4$) are a wide range of applications such as a phosphor host and an important crystalline phase in glass ceramics, electrical insulators, glazes, and pigments. In this study, Willemite precursors were synthesized with zinc silicate gels from mixture of zinc nitrate solution and various sodium silicate solution by the geopolymer technique. To examine the crystallization behavior, precursors were have been monitored by the XRD. A pure willemite phase was obtained at $900^{\circ}C$. TEM investigations revealed that the sample with 50 nm particle size was obtained via heat-treated at $900^{\circ}C$ for W-3.

The Fabrication of Low Cost High Temperature Superconducting Tape (저비용 고온초전도 선재 제조 연구)

  • 한상철;성태현;한영희;이준성;이영우;정년호;김상준
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2000.02a
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    • pp.85-88
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    • 2000
  • Cu-free Bi-Sr-Ca-O powder mixtures were screen-printed on Cu tapes and heat-treated at 850-$870^{\circ}C$ for several minutes in air, oxygen, nitrogen and low oxygen pressure. Cu-free precursors were composed of Bi_{x}$SrCaO_{y}$ (x=1.2-2). In order to obtain the optimum heat-treatment condition, we studied on an effect of the precursor composition, the printing thickness and the heat-treatment atmosphere on the superconducting properties of Bi2212 films and the reaction mechanism of their rapid formation. Microstructures and phases of thick films were analyzed by optical microscope and XRD. The electric properties of superconducting films were examined by the four probe method. At heat-treatment temperature, the thick films were in a partially molten state by liquid reaction between CuO in the oxidized copper tape and the precursors which were printed on Cu tapes.

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Synthesis of Cobalt Oxide Film by Thermal Decomposition for Potential Various Applications

  • Han, Seong Ho;Park, Bo Keun;Son, Seong Uk;Kim, Chang Gyoun;Chung, Taek-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.365.1-365.1
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    • 2014
  • Cobalt oxide has excellent various properties such as high catalytic activity, antiferromagnetism, and electrochromism. So cobalt oxides offer a great potential for their applications in the various areas such as optical gas sensor, catalysts for oxidation reaction, electrochromic devices, high temperature solar selective absorbers, magnetic materials, pigment for glasses and ceramics, and negative electrodes for lithium-ion batteries. We have synthesized novel cobalt complexes by simple reaction of cobalt bistrimethylsilylamide as a starting material with a lot of conventional ligands as potential cobalt oxide precursors. The studies include the facile preparation, structural characterization, and spectroscopic analysis of the new precursors. We are making efforts to grow cobalt oxide thin films using cobalt complexes newly synthesized in this study using deposition techniques.

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Synthesis and Characterization of New Nickel Sulfide Precursor

  • Lee, Sang Chan;Park, Bo Keun;Chung, Taek-Mo;Hong, Chang Seop;Kim, Chang Gyoun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.365.2-365.2
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    • 2014
  • Nickel sulfide (NiS) has been utilized in optoelectronic applications, such as transformation-toughening agent for materials used in semiconductor applications, catalysts, and cathodic materials in rechargeable lithium batteries. Recently, high quality nickel sulfide thin films have been explored using ALD/CVD technique. Suitable precursors are needed to deposit thin films of inorganic materials. However, nickel sulfide precursors available for ALD/CVD process are very limited to nickel complexes with dithiocarbamate and alkanethiolate ligands. Therefore, it is essential to prepare novel nickel sulfide suitable for ALD/CVD precesses. Herein we report on the synthesis and characterization of new nickel sulfide complex with designed aminothiolate ligand. Furthermore thin films of NiS have been prepared on silicon oxide substrates by spin coating nickel precursor 10 wt% in THF. The novel complex has been characterized by means of 1H-NMR, elemental analysis, thermogravimetric analysis (TGA), X-ray Diffraction (XRD) and scanning electron microscope (SEM).

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Characterization of (Y,Gd) $BO_3$:Eu Phosphors Prepared by Urea Hydrolysis Method

  • Park, Jung-Min;Kim, Chang-Hae;Jung, Ha-Kyun;Park, Hee-Dong;Park, Yoon-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.792-794
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    • 2002
  • Uniform cylinder-shaped precursors for (Y,Gd)$BO_3$:Eu phosphors were prepared by urea hydrolysis reaction. After heating the precursors at lower temperature than general synthetic methods, the phosphor powders were well dispersed and held their original shapes. Their emissions under vacuum-ultraviolet (VUV) excitation appeared with the peaks at 593nm due to magnetic dipole transition from $^5D_0$ to $^7F_1$, 612nm and 627nm due to electric dipole transition from $^5D_0$ to $^7F_2$

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