• Title/Summary/Keyword: hexagonal

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Facile Preparation of Pyrene-templated Hexagonal-shaped Gold Nanoplates

  • Lim, Eun-Kyung;Jang, Eunji;Haam, Seungjoo;Huh, Yong-Min
    • Applied Science and Convergence Technology
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    • v.23 no.1
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    • pp.48-53
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    • 2014
  • We have formulated hexagonal-shaped gold nanoplates in a single-step for photothermal therapy that gold ions to gold particles using pyrenyl dextran as reducible stabilizer and template. They exhibit anisotropic structure with broad surface plasmon resonance (SPR) band into near-infrared (NIR) spectrum enabling photothermal therapy. These gold nanoplates are also confirmed biocompatibility and high uptake efficiency due to binding with dextran molecules on the surface of gold nanoplates and cells. From in vitro phtothermal ablation study under NIR laser, gold nanoplates have the potential to use as photothermal agents.

A Hybrid DTC-DSC Drive for High Performance Induction Motor Control

  • Jidin, Auzani;Idris, Nik Rumzi Nik;Yatim, Abdul Halim Mohamed;Sutikno, Tole;Elbuluk, Malik E.
    • Journal of Power Electronics
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    • v.11 no.5
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    • pp.704-712
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    • 2011
  • This paper describes a hybrid induction motor drive system incorporating DTC-hysteresis and Direct Self Control (DSC) schemes to achieve excellent dynamic performance. The control scheme is switched from a circular to a hexagonal flux locus whenever a dynamic condition is encountered. On the other hand, when the motor operates under steady state conditions, a circular flux locus is used. Without major modifications to the simple structure of a basic DTC, hexagonal flux locus operation is established by modifying the flux error status, before it is fed to the look-up table. The feasibility of the proposed hybrid scheme to achieve excellent control performance is verified by experimental results.

Chemical Composition and Thermal Changes of Natural Pyrrhotite

  • Moon-Young Kim;Hong-Ja Shin
    • Journal of the Mineralogical Society of Korea
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    • v.3 no.2
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    • pp.65-71
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    • 1990
  • Compositions and thermal changes of pyrrhotites from Ohtani and Uljin mines were examined by Arnold's method and DTA analysis. The results are as follow: 1) The compositions of hexagonal type pyrrhotite are in some range from 47.23-47.42 atom.% Fe in the Ohtani mine, and 47.40-47.64 atom.% Fe in the Uljin mine. 2) The compositions of hexagonal pyrrhotite with exsoluted lamellae of monoclinic pyrrhotite are in 47.35-47.50 atom.% Fe in the Ohtani mine, and 47.15-47.40 atom.% Fe in the Uljin mine. This fact does not agree with phase diagrams of Fe-S system shown by Nakazawa and Morimoto(1970) and Sugaki and Shima(1977). 3) DTA data show two endothermic peak corresponding to ${\gamma}$ and $\beta$ transformation. Sturctural conversions from order(intermediate) to disorder(high) forms occur at about $300^{\circ}C$ for hexagonal type and further lower temperature with increasing Fe-content.

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Crystal Chemistry of Hexagonal 7$\AA$ Phyllomanganate Minerals (7$\AA$ 층상구조형 산화망간 광물의 결정화학)

  • 김수진
    • Journal of the Mineralogical Society of Korea
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    • v.3 no.1
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    • pp.34-43
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    • 1990
  • Crystal-chemical study of hexagonal 7$\AA$ phyllomanganate minerals reveals that they have hexagonal layer structures with variable c dimensions which depend on the nature of interlayer cations and content of water molecules between edge-sharing [MnO6] octahedral layers. Approximately one out of nine octahedral sites is statistically vacant, leading to the general unit cell formula R2xMn4+1-xO2.nH2O, where R=Ca, Mn2+, Mg, K, Na;x=0.09-0.14 ; n-0.37-0.84. Z=1. The minerals of this formula fall under the name of rancieite group. It includes Ca-diminant (rancieite), Mn2+-dominant (takanelite), Na-dominant (birnessite), and Mg-dominant members. Minerals of the rancieite group occur predominantly in two different hydration states, i.e., n shows the values around 0.35 and 0.75. It is suggested that minerals of higher hydration state be called as species(i.e., rancieite, etc.) and those of lower hydration state be called as dehydrated varieties(i.e., dehydrated rancieite,etc.).

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High pressure X-ray diffraction study on a graphite using Synchrotron Radiation (고압하에서 방사광을 이용한 흑연에 대한 연구)

  • Kim, Young-Ho;Na, Ki-Chang
    • The Journal of the Petrological Society of Korea
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    • v.3 no.1
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    • pp.34-40
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    • 1994
  • High pressure X-ray diffraction study was carried out on a graphite to investigate its compressibility as well as any possible phase transition to the hexagonal diamond structure at room temperature. Energy dispersive X-ray diffraction method was introduced using a Mao-Bell type diamond anvil cell with Synchrotron Radiation. Polycrystalline sodium chloride was compressed together with graphite for the high pressure determinations. Because of the poor resolution of the X-ray diffraction pattern of graphite, its compressibility was estimated to be almost same as that of NaCl by graphite (002) X-ray diffraction peak only. An observation of any new peak from a possible hexagonal diamond phase seems very unplausible for its definite identification based on the present data. Alternative approaches such as an Wiggler Radiation source as well as a Large Volume high pressure apparatus will be necessary for the detailed studies on a graphite in future.

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Design of a Polarization Splitter Based on a Dual-core Hexagonal-shaped Photonic Crystal Fiber

  • Jegadeesan, Subramani;Dhamodaran, Muneeswaran;Azees, Maria;Murugan, Arunachalam
    • Current Optics and Photonics
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    • v.3 no.4
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    • pp.304-310
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    • 2019
  • In this paper, a microstructured, hexagonal-shaped dual-core photonic crystal fiber (PCF) is proposed. The proposed structure has specific optical properties to obtain high birefringence and short coupling length, for different values of structural parameters varied over a wide range of wavelength. The properties are analyzed using a solid core of silica material. The proposed structure is implemented as a polarization splitter with splitting length of 1.9 mm and a splitting ratio of -34.988 dB, at a wavelength of 1550 nm. The obtained bandwidth in one band gap of about 81 nm. The numerical analysis ensures that the performance of the proposed polarization splitter is better than that of existing ones.

OPTIMIZATION OF STOCK MANAGEMENT SYSTEM WITH DEFICIENCIES THROUGH FUZZY RATIONALE WITH SIGNED DISTANCE METHOD IN SEABORN PROGRAMING TOOL

  • K. KALAIARASI;N. SINDHUJA
    • Journal of applied mathematics & informatics
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    • v.42 no.2
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    • pp.379-390
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    • 2024
  • This study proposes a fuzzy inventory model for managing large-scale production, incorporating cost considerations. The model accounts for two types of expenditure scenarios-parametric and exponential. Uncertainty surrounds holding costs, setup costs, and demand rates. The approach considers a supply chain system with a complex manufacturing process, factoring in transportation costs based on the quantity of goods and distance between the supplier and retailer. The initial crisp model is then transformed into a fuzzy simulation, incorporating specific fuzzy variables affecting inventory costs. The proposed method significantly reduces overall inventory costs for the entire supply chain. Retailer demand is linked to inventory levels, and vendor/distributor storage deteriorates over time. The fuzzy condition assumes hexagonal variables for all associated factors. The study employs the signed distance method for defuzzification to determine the optimal order quantity with hexagonal fuzzy numbers. Mathematical examples are provided to illustrate the practicality of the proposed approach.

Studies on the Transovarial Transmission of Cytoplasmic Polyhedrosis Virus with Reference to the Phenomena of Induction, Interference and Virulence Enhancement in the Silkworm, Bombyx mori (가잠 세포질다각체 바이러스의 유발, 간섭 및 병원성 증진현상에 의한 경난전달에 관한 연구)

  • 임종성
    • Journal of Sericultural and Entomological Science
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    • v.16 no.2
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    • pp.55-75
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    • 1974
  • Transovarial transmission of cytoplamic polyhedrosis virus in the silkworm was studied by observing the phenomena of induction, interference and virulence enhancement in the larvae from moths inoculated with hexagonal Polyhedra of cytoplasmic polythedrosis virus. The experimental results obtained are as followings. 1. The effect of inoculation with tetragonal polyhedra of cytoplasmic polyhedrosis virus on the rate of infective induction with hexagonal polyhedron virus and with hexagonal plus tetragonal polyhedron viruses in the larvae from moths infected with hexagonal polyhedron virus was studied. Infection rate was higher by 40 to 60 percent in the larvae from infected female group than in tile larvae from noninfected female group. 2. In the studies of the effect of formalin-feeding on the induction of infection with hexagonal polyhedron virus, infection rate was higher by 40 percent in the larvae from infected female group than in the larvae from noninfected female group. However, there was no significant difference in the infection rates between the two formalin-concentration groups. 3. The effect of cold treatment on the induction of infection with hexagonal polyhedron virus was studied. Infection rate was higher by 50 percent in the larvae from infected female group than ill the larvae from noninfected female group. No difference was found in the infection rates of the two treatment groups of 12 and 48 hours. 4. The phenomena of induction and interference were studied by observing rate of infection with hexagonal polyhedron virus induced by the inoculation with tetragonal polyhedron virus. The degree of interference of primary hexagonal polyhedron virus by secondary tetragonal Ployhedron virus was increased as the dosage of secondary virus was increased. At the concentration of 1${\times}$10$\^$8/m1 of the secondary virus, the degree of interference was similar to. that of control group. On the other hand, infection with tetragonal polyhedron virus at low concentration was interfered by the primary virus. At the concentration of 1N10f/m1 of tetragonal polyhedron virus, however, the rate of infection with tetragonal polyhedron virus was increased sharply, which is still lower by 30 percent than that of control group. 5. In the studies of induction and virulence enhancement, based on the 1ate of mixed infection with hexagonal and tetragonal polyhedron viruses, the highest difference of infection rate between experimental group and control group exceeded 40 percent when the concentration of tetragonal polyhedron virus was 1${\times}$10$\^$7/m1. However, the infection rate of control group was not affected by concentrations of tetragonal polyhedron virus.

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Analysis of Light Transmittance according to the Array Structure of Collagen Fibers Constituting the Corneal Stroma (각막실질 콜라겐섬유의 배열구조에 따른 광투과율 분석)

  • Lee, Myoung-Hee;Kim, Young-Chul
    • The Korean Journal of Vision Science
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    • v.20 no.4
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    • pp.561-568
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    • 2018
  • Purpose : The size and regular array of the collagen fibers in the corneal stroma have very close correlation with transparency. Simulation was carried out to investigate the change of light transmittance according to the array structure and collagen fiber layer thickness. Methods : The collagen fibers in corneal stroma were arranged in regular hexagonal, hexagonal, square and random shapes with OptiFDTD simulation software, and the light transmittance was analyzed. In square array, the light transmittance according to the density change was confirmed by when the number of collagen fibers in the simulation space was the same and the light transmittance was examined when the number and density of collagen fibers were changed. Results : When the number of collagen fibers is the same, the density becomes smaller and the thickness of the fibrous layer becomes thicker in order of arrangement of square, regular hexagonal, random and hexagonal. As a result of measuring the light transmittance by changing the array structure, the light transmittance measured at the detector at the same position was almost similar regardless of the array structure. In the detectors D0, D1, D2 and D3, the maximum transmittance is shown in square, hexagonal and square, regular hexagonal and regular hexagonal array structure, and the minimum transmittance is hexagonal, random, hexagonal and square, and square array structure. However, the difference between the maximum transmittance and the minimum transmittance was almost the same within 1%. When the number of collagen fibers was the same, the light transmittance of the rectangular array structure decreased with increasing fiber layer thickness. And as the thickness increased, the light transmittance decreased more when the number of collagen fibers decreased. Conclusion : Even though the collagen array structure changed, the light transmittance is almost similar regardless of the arrangement structure. However, as the array structure was changed, the thickness of the collagen fiber layer changed, and as the thickness increased, the light transmittance decreased. In other words, the transparency of the corneal stroma is more closely related to the thickness of the fibrous layer than the array of collagen fibers.

Space Group $R\={3}c$ = $R\={3}2/c$(167) and the Crystal Structure of Tris(1,2,3,4-tetraphenylbuta-1,3-dienyl)cyclotriphosphazene (Space Group $R\={3}c$(167)과 Tris(1,2,3,4-tetraphenylbuta-1,3-dienyl)cyclotriphosphazene의 結晶構造)

  • Kim, Young-Sang;Ko, Jae-Jung;Kang, Sang-Ook;Lee, Young-Joo;Kang, Eu-Gene;Han, Won-Sik;Park, Young-Soo;Suh, Il-Hwan
    • Korean Journal of Crystallography
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    • v.15 no.1
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    • pp.9-17
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    • 2004
  • There are 25 space groups in the trigonal system. Eighteen out of them have a lattice letter P displaying only hexagonal axes, wherease the remaining seven rhombohedral space groups R3(146), $R\={3}$(148), R32(155), R3m(160), R3c(161), $R\={3}m$(166) and $R\={3}c$(167) are described with two corrdinate systems, first with hexagonal axes having three lattice points (0, 0, 0), (2/3, 1/3, 1/3), (1/3, 2/3, 2/3) and second with primitive rhombohedral axes. In this paper, the space group $R\={3}c$ is discussed and the crystal structure of a compound, tris(1,2,3,4-tetraphenylbuta-1,3-dienyl)cyclotriphosphazene, $C_{84}H_{60}N_3P_3$, belonging to the space group $R\={3}c$ is elucidated with both hexagonal and rhombohedral cells.