• Title/Summary/Keyword: branching surface

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Two new species of genus Luffariella (Dictyoceratida: Thorectidae) from Korea

  • Sim, Chung Ja;Lee, Kyung Jin;Kim, Young A
    • Journal of Species Research
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    • v.6 no.2
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    • pp.190-194
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    • 2017
  • Two new species of the genus Luffariella (Dictyoceratida: Thorectidae), L. tubula n. sp. and L. koreana n. sp. were collected from Jeju-do, Korea. These species differ significantly from the previously reported five species in terms of shape and skeletal structure. L. tubula n. sp. has two categories in thickness of secondary fibres which were different from other species. L. koreana n. sp. is very similar to L. variabilis from Tahiti in skeletal structure, but differs in sponge shape with irregular branching and indistinct surface conules. Primary fibres of the two new species are separated from secondary and tertiary fibres.

Loss of HCN from the Pyrimidine Molecular Ion: A Computational Study

  • Yim, Min Kyoung;Jung, Sun Hwa;Kim, Myung Soo;Choe, Joong Chul
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4098-4102
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    • 2012
  • The potential energy surface (PES) for the loss of HCN from the pyrimidine molecular ion has been explored using quantum chemical calculations. Possible reaction pathways to form five $C_3H_3N^{+{\bullet}}$ isomers have been obtained with Gaussian 4 model calculations. The rate constant for the HCN loss and the product branching ratio have been calculated using the Rice-Ramsperger-Kassel-Marcus theory on the basis of the obtained PES. The resultant rate constant agrees with the previous experimental result. By a kinetic analysis, it is proposed that the formation of $CH=CHC{\equiv}NH^{+{\bullet}}$ is favored near the dissociation threshold, while the formation of $CH=CHN{\equiv}CH^{+{\bullet}}$ is favored at high energies.

Displacement Properties of Nano Structure Dendrimer

  • Song Jin-Won;Lee Kyung-Sup;Lee Woo-Ki;Choi Young-Il;Yoon Suk-Am;Choi Chung-Seog
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.1
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    • pp.28-32
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    • 2005
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

Displacement Current Properties for Nano Structure Dendrimer (나노구조 덴드리머의 변위전류 특성)

  • Song, Jin-Won;Choi, Yong-Sung;Lee, Woo-Ki;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.05a
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    • pp.52-54
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multi layers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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Fracture Toughness and Crack Growth Resistance of the Fine Grain Isotropic Graphite

  • Kim, Dae-Jong;Oh, Seung-Jin;Jang, Chang-Heui;Kim, In-Sup;Chi, Se-Hwan
    • Carbon letters
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    • v.7 no.1
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    • pp.19-26
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    • 2006
  • Three point bending tests of single edge notched beam (SENB) specimens were carried out to evaluate the fracture behavior of the fine-grain isotropic nuclear grade graphite, IG-11. To measure the crack initiation point and the subsequent crack growth, the direct current potential drop (DCPD) method and a traveling microscope were used. The effects of test variables like initial crack length, specimen thickness, notch type and loading rate on the measured fracture toughness, $K_Q$, were investigated. Based on the test results, the ranges of the test variables to measure the reliable fracture toughness value were proposed. During the crack growth, the rising R-curve behavior was observed in IG-11 graphite when the superficial crack length measured on the specimen surface was used. The increase of crack growth resistance was discussed in terms of crack bridging, crack meandering, crack branching, microcracking and crack deflection, which increase the surface energy and friction force.

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A Study on Electrical Properties of Dendrimer (덴드리머의 전기적 특성 연구)

  • Choi, Yong-Sung;Song, Jin-Won;Lee, Woo-Ki;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1330-1332
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The agobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the Presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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Photo Stimulus Displacement Properties of Nano structure Organic Ultra Thin Films (나노구조 유기초박막의 광자격 변위특성)

  • Song, Jin-Won;Cho, Su-Young;Choi, Young-Il;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2004.11a
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    • pp.209-211
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    • 2004
  • In the Langmuir-Boldgett(LB) technique, a monolayer on the water surface is transferred on to a substrate, which is raised and dipped through the surface, and one can obtain multilayers in which constituent molecules periodically are arranged in layer. The LB technique has attracted considerable interest in the fabrication of electrical and electronic device, e.g.. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules sharacterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends, which distinguishes dendrimers from conventional starlike polymers and microgels. Azobenzene dendrimer is one of the dendritic macromolecules that includes the azo-group which exhibits a photochromic character. Due to the presence of the charge transfer part, the azo-group, and having a rod-shaped structure, these compounds are expected to have the potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give a pressure stimulation into organic thin films and detect the induced displacement current.

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Displacement Current Characteristics of Nano-Structural Dendrimer (나노구조 덴드리머의 변위전류 특성)

  • Song, Jin-Won;Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.358-359
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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Effects of $N_2/H_2$ plasma treatments on enhancement of neuronal cell affinity on single-walled carbon nanotube paper scaffolds

  • Yoon, Ok-Ja;Lee, Hyun-Jung;Jang, Yeong-Mi;Kim, Hyun-Woo;Lee, Won-Bok;Kim, Sung-Su;Lee, Nae-Eung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.393-393
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    • 2010
  • The biocompatibility of materials used for biomedical applications depends on chemical composition, mechanical stiffness, surface energy, and roughness. The plasma treatment and etching process is a very important technology in the biomedical fields due to possibility of controlling the surface chemistry and properties of materials. In this work, $N_2/H_2$ plasma were treated on single-walled carbon nanotubes (SWCNTs) paper and characterization of treated SWCNTs paper was carried out. Also we investigated neurite outgrowth from SH-SY5Y on treated SWCNTs paper. The results indicated that $N_2/H_2$ plasma-modified SWCNTs paper enhanced neuronal cell adhesion, viability, neurite outgrowth and branching in vitro and exerted a positive role on the health of neural cells.

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Generation of Triangular Mesh of Coronary Artery Using Mesh Merging (메쉬 병합을 통한 관상동맥의 삼각 표면 메쉬 모델 생성)

  • Jang, Yeonggul;Kim, Dong Hwan;Jeon, Byunghwan;Han, Dongjin;Shim, Hackjoon;Chang, Hyuk-jae
    • Journal of KIISE
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    • v.43 no.4
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    • pp.419-429
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    • 2016
  • Generating a 3D surface model from coronary artery segmentation helps to not only improve the rendering efficiency but also the diagnostic accuracy by providing physiological informations such as fractional flow reserve using computational fluid dynamics (CFD). This paper proposes a method to generate a triangular surface mesh using vessel structure information acquired with coronary artery segmentation. The marching cube algorithm is a typical method for generating a triangular surface mesh from a segmentation result as bit mask. But it is difficult for methods based on marching cube algorithm to express the lumen of thin, small and winding vessels because the algorithm only works in a three-dimensional (3D) discrete space. The proposed method generates a more accurate triangular surface mesh for each singular vessel using vessel centerlines, normal vectors and lumen diameters estimated during the process of coronary artery segmentation as the input. Then, the meshes that are overlapped due to branching are processed by mesh merging and merged into a coronary mesh.