Autor: Cho, H. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Improvement of Microwave Absorbance of Polymer Composites of W-Type Hexaferrite Powders by Attachment of Frequency Selective Surface
Autorzy:: Cho, H.-S.
Kim, S.-S.
Powiązania:: https://bibliotekanauki.pl/articles/352824.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: frequency selective surface
microwave absorbers
hexaferrite powders
polymer composites
Opis:: This work investigates the effect of a frequency selective surface (FSS) composed of a regular array of square loop elements on the absorption properties of grounded ferrite composites. Polymer matrix composites of CoZnW hexaferrite powders having small magnetic loss were used as the substrate material. Computational tools were used to model the interaction between electromagnetic waves and materials and determine the reflection coefficient. Reflection loss and bandwidth were greatly improved by attaching an FSS with controlled electrical resistance (R) onto the grounded ferrite composites. For the FSS with R = 800 Ω, the minimum reflection loss decreased to –25 dB at 10 GHz and the bandwidth was broadened to 7.5-12.5 GHz with respect to –10 dB reflection loss.
Źródło:: Archives of Metallurgy and Materials; 2017, 62, 2B; 1325-1328
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: A New 3D Sensor System by Using Virtual Camera Model and Stereo Vision for Mobile Robots
Autorzy:: Lee, H.
Kim, M. N.
Cho, H.
Powiązania:: https://bibliotekanauki.pl/articles/384962.pdf
Data publikacji:: 2008
Wydawca:: Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:: virtual camera model
stereo vision
Opis:: So many researches have been conducted to develop 3D sensing method for mobile robots. Among them, the optical triangulation, a well-known method for 3D shape measurement, is also based on active vision sensing principle for mobile robot sensor system, so that the measurement result is robust to illumination noises from environments. Due to this advantage it has been popularly used. However, to obtain the 3D information of environment needs a special scanning process and scanning actuators need. To omit this scanning process multi-line projection methods have been widely researched. However, they suffer from an inherent limitation: The results of multi-line projection method commonly have measurement errors because of 2 -ambiguity caused by regularly repeated multiline laser pattern. In this paper, to overcome 2 -ambiguity effectively, we introduce a novel sensing method for a 3D sensing system using multi-line projection and stereo cameras, based on the virtual camera model and stereovision algorithm. To verify the efficiency and accuracy of the proposed method, a series of experimental tests is performed.
Źródło:: Journal of Automation Mobile Robotics and Intelligent Systems; 2008, 2, 4; 38-44
1897-8649
2080-2145
Pojawia się w:: Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Electron impact excitation and dissociation of halogen-containing molecules
Autorzy:: Kitajima, M.
Suzuki, R.
Tanaka, H.
Pichl, L.
Cho, H.
Powiązania:: https://bibliotekanauki.pl/articles/148521.pdf
Data publikacji:: 2003
Wydawca:: Instytut Chemii i Techniki Jądrowej
Tematy:: crossed beam experiment
dissociation
dissociative attachment
differential cross section
electron impact
Opis:: A systematic analysis of the absolute differential cross sections (DCSs) for electron scattering by halogen-containing molecules CF3X (X = H, F, Cl, Br, I) has been performed with impact energy and scattering angle ranging from 1.5 to 100 eV and 15 to 130°, respectively. Three of the results of these experiments are described in the present report. Firstly, a clear difference is demonstrated in the elastic-scattering cross section angular distributions of polar and nonpolar molecules with the substitution of one of the F atoms in CF4 for a H, Cl, Br or I atom. Secondly, vibrational excitation spectra of the unresolved composite modes (mainly CF3 stretching) for CF3X reveal a common broad structure in the region from 7 to 9 eV due to shape resonance. The third result presented is the observation of a low-lying electronic state of CF3Cl, CF3Br, and CF3I. This feature is enhanced at lower incident energies and larger scattering angles. Also discussed are some preliminary results on the formation of negative and neutral fragments from SiF4 and CH4 by electron impact.
Źródło:: Nukleonika; 2003, 48, 2; 89-93
0029-5922
1508-5791
Pojawia się w:: Nukleonika
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Effect Of Carbon Nanotubes On The Properties Of Spark Plasma Sintered ZrO2/CNT Composites
Wpływ nanorurek węglowych na właściwości spiekanych metodą sps kompozytów ZrO2/CNT
Autorzy:: Shim, D. H.
Jung, S. S.
Kim, H. S.
Cho, H.
Kim, J. K.
Kim, T. G.
Yoon, S. J.
Powiązania:: https://bibliotekanauki.pl/articles/351266.pdf
Data publikacji:: 2015
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: CNT
ZrO2
composite
SPS
kompozyty
Opis:: Zirconia matrix ZrO2/CNT composite materials reinforced with multiwall carbon nanotubes were fabricated using a spark plasma sintering technique. The effects of the amount of CNTs addition, sintering temperature and sintering pressure on the properties of the resulting ZrO2/CNT composites were examined. 0 to 9 vol. % CNTs were dispersed in zirconia powder, and the resulting mixture was sintered. The electrical conductivity, hardness, flexural strength, and density were measured to characterize the composites. The friction and wear properties of the composites were also tested. The flexural strength and friction coefficient of the composites were improved with up to 6 vol.% of CNT addition and the flexural strength showed a close relationship with the relative density of the composite. The electrical conductivity increased with increasing proportion of the CNTs, but the efficiency was reduced at more than 6 vol.% CNTs.
Źródło:: Archives of Metallurgy and Materials; 2015, 60, 2B; 1315-1318
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Fabrication and Characterization of CoCrFeNiMn High Entropy Alloy Powder Processed by Gas Atomization
Autorzy:: Park, T. G.
Lee, S. H.
Lee, B.
Cho, H. M.
Choi, W. J.
Kim, B. S.
Shin, K. S.
Kim, T.-S.
Powiązania:: https://bibliotekanauki.pl/articles/353649.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: high entropy alloy
gas atomization
spark plasma sintering
CoCrFeNiMn
Opis:: In this study, precisely controlled large scale gas atomization process was applied to produce spherical and uniform shaped high entropy alloy powder. The gas atomization process was carried out to fabricate CoCrFeNiMn alloy, which was studied for high ductility and mechanical properties at low temperatures. It was confirmed that the mass scale, single phase, equiatomic, and high purity spherical high entropy alloy powder was produced by gas atomization process. The powder was sintered by spark plasma sintering process with various sintering conditions, and mechanical properties were characterized. Through this research, we have developed a mass production process of high quality and spherical high entropy alloy powder, and it is expected to expand applications of this high entropy alloy into fields such as powder injection molding and 3D printing for complex shaped components.
Źródło:: Archives of Metallurgy and Materials; 2018, 63, 2; 1055-1059
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Multistep Heat-Treatment Effects on Electrospun Nd-Fe-B-O Nanofibers
Autorzy:: Jeon, E. J.
Eom, N. S. A.
Lee, J.
Lee, B.
Cho, H. M.
On, J. S.
Choa, Y.-H
Kim, B. S.
Powiązania:: https://bibliotekanauki.pl/articles/354311.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: Nd-Fe-B
nanofibers
electrospinning
heat treatment
Opis:: Neodymium-Iron-Boron (Nd-Fe-B) magnets are considered to have the highest energy density, and their applications include electric motors, generators, hard disc drives, and MRI. It is well known that a fiber structure with a high aspect ratio and the large specific surface area has the potential to overcome the limitations, such as inhomogeneous structures and the difficulty in alignment of easy axis, associated with such magnets obtained by conventional methods. I n this work, a suitable heat-treatment procedure based on single-step and multistep treatments to synthesize sound electrospun Nd-Fe-B-O nanofibers of Φ572 nm was investigated. The single-step heat-treated (directly heat-treated at 800°C for 2 h in air) samples disintegrated along with the residual organic compounds, whereas the multistep heat-treated (sequential three-step heat-treated including three steps;: dehydration (250°C for 30 min in an inert atmosphere), debinding (650°C for 30 min in air), and calcination (800°C for 1 h in air)) fibers maintained sound fibrous morphology without any organic impurities. They could maintain such fibrous morphologies during the dehydration and debinding steps because of the relatively low internal pressures of water vapor and polymer, respectively. In addition, the NdFeO₃ alloying phase was dominant in the multistep heat-treated fibers due to the removal of barriers to mass transfer in the interparticles.
Źródło:: Archives of Metallurgy and Materials; 2018, 63, 3; 1433-1437
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Anther and microspore cultures of barley and wheat
Autorzy:: Kasha, K J
Ziauddin, A
Cho, U H
Simion, E
Petroski, R
Cistue, L
Powiązania:: https://bibliotekanauki.pl/articles/2046611.pdf
Data publikacji:: 1997
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: transformation
isolated microspore
doubled haploid
wheat
microspore culture
barley
anther culture
Opis:: This paper briefly cites the various procedures for the production of doubled haploids in barley and wheat. Various associated terms are defined and the factor involved in haploid production are outlined. Isolated microspore cultures offer some advantages over anther culture. Our current procedures for isolated microspore culture of barley and wheat are presented and compared.
Źródło:: Journal of Applied Genetics; 1997, 38, 4; 373-380
1234-1983
Pojawia się w:: Journal of Applied Genetics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Fabrication of Porous Silica Fibers by Electrospinning for Sound Absorbing Materials
Autorzy:: Cho, Y.-S.
Lee, H. J.
Powiązania:: https://bibliotekanauki.pl/articles/353561.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: electrospinning
porous silica fiber
thermal insulator
sound absorption
Opis:: Macroporous silica fibers having spherical cavities were fabricated by electrospinning using the spinning solution prepared from the mixed dispersion of tetraethylorthosilicate (TEOS) and polystyrene nanospheres as precursor and sacrificial templates, respectively, by injection through metallic nozzle. By applying electric field, the electro-spun fibers obtained by evaporation-driven self-assembly were collected on flat substrate or rotating drum, followed by the removal of the templates by calcination. The sound absorption coefficient of the porous fibers was measured by impedance tube, and the measured value was larger than 0.9 at high frequency region of incident waves. The surface of the resulting fibers was modified using fluorine-containing silane coupling agent to produce superhydrophobic fibrous materials to prevent the infiltration of humidity.
Źródło:: Archives of Metallurgy and Materials; 2018, 63, 3; 1497-1502
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: A Fatigue Fracture Study on TDCB Aluminum Foam Specimen of Type Mode III Bonded with Adhesive
Autorzy:: Lee, J. H.
Cho, J. U.
Powiązania:: https://bibliotekanauki.pl/articles/356731.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: aluminum foam
fatigue fracture
fatigue analysis
load
Mode III type
specimen thickness
Opis:: This paper studies the characteristics of junction structure of closed-cell type aluminum foam, which is generally used as a shock absorber. TDCB specimens were designed for mode III type with thickness as a variable and performed a fatigue experiment on them by thickness. As the result, the load value of all specimens peaks under 0 to 25 cycles and decreases as the cycles increase. As the specimen thickens by 10 mm, the maximum load value is 1.2 times. When the thickness increases by 20 mm, the maximum value increases by 1.5 times. This study result can be utilized by investigating the mechanical characteristics of TDCB specimens for mode III type under fatigue loading conditions systematically and efficiently.
Źródło:: Archives of Metallurgy and Materials; 2017, 62, 2B; 1359-1362
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Experimental Study On Fracture Property Of Double Cantilever Beam Specimen With Aluminum Foam
Doświadczalne badanie pękania mimośrodowo rozciąganej próbki z bocznym karbem wykonanej z piany aluminiowej
Autorzy:: Kim, Y. C.
Choi, H. K.
Cho, J. U.
Powiązania:: https://bibliotekanauki.pl/articles/351465.pdf
Data publikacji:: 2015
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: aluminium foam
double cantilever beam
fracture energy
adhesively bonded structure
piana aluminiowa
podwójna belka wspornikowa
energia pękania
Opis:: This study aims to investigate double cantilever beam specimen with aluminum foam bonded by spray adhesive to investigate the fracture strength of the adhesive joint experimentally. The fracture energy at opening mode is calculated by the formulae of British Engineering Standard (BS 7991) and International Standard (ISO 11343). For the static experiment, four types of specimens with the heights (h) of 25 mm, 30 mm, 35 mm and 40 mm are manufactured and the experimental results are compared with each other. As the height becomes greater, the fracture energy becomes higher. After the length of crack reaches 150 mm, the fracture energy of the specimen (h=35 mm) is greater than that of the specimen (h=40 mm). Fatigue test is also performed with DCB test specimen. As the height decreases, the fracture energy becomes higher. By the result obtained from this study, aluminum foam with adhesive joint can be applied to actual composite structure and its fracture property can possibly be anticipated.
Źródło:: Archives of Metallurgy and Materials; 2015, 60, 2B; 1151-1154
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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