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    Wyświetlanie 1-85 z 85
    Tytuł:
    Effects of PVA Polymer Type and Calcination Temperature on Synthesis of Nanocrystalline Yttria Powder by Polymer Solution Route
    Autorzy:
    Yang, Y.-K.
    Lee, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/356024.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    yttria
    PVA
    nanocrystalline
    synthesis
    nanowire
    Opis:
    Nano-sized yttria (Y2O3) powders were synthesized by a polymer solution route using polyvinyl alcohol (PVA) as an organic carrier. The PVA polymer affected the dispersion of yttrium ions in precursor sol. In this study, three kinds of PVA polymer (different molecular weight) were applied for synthesis of yttria powder. The PVA type as well as calcination temperature had a strongly influence on the particle morphology. Single crystal nano wire particles were observed at the temperature of polymer burn out range and the size was dependent on the PVA type. The stable, fully crystallized yttria powder was obtained through the calcination at 800°C for 1 h. The yttria powder prepared with the high weight PVA (MW: 153,000) revealed a particle size of 30 nm with a surface area of 18.8 m2/g.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1473-1476
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hearing impairment among Korean farmers, based on a 3-year audiometry examination
    Autorzy:
    Lee, S.
    Lee, K.
    Lee, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2082988.pdf
    Data publikacji:
    2019
    Wydawca:
    Instytut Medycyny Wsi
    Tematy:
    agriculture
    sensorineural hearing loss
    audiometry
    Opis:
    Introduction and objective. Work noise exposure among farmers can cause hearing loss. Farmers are exposed to hazardous noise from equipment and domestic animals, and experience high rates of noise-induced hearing loss. The aim of our study was to evaluate the hearing thresholds of farmers in Korea. This study is the first to evaluate hearing impairment in Korean farmers nationwide. There have been few studies that have performed audiometric testing to measure hearing impairment at the national level in Korea. Materials and method. Through the Farm Work Safety Model Project among the 40 villages in which inhabitants received health check-ups from 2006–2008, 2,027 people from 35 villages were targeted (957 people in 16 villages in 2006, 436 people in five villages in 2007, and 634 people in 14 villages in 2008) and underwent pure tone audiometry tests. 2,027 people from 35 villages underwent pure tone audiometry tests through the Farm Work Safety Model Project. The tests were conducted using a portable audiometer, and air conduction thresholds were determined. Results. Hearing impairment at 3kHz and above was more prevalent in men than in women. The prevalence of moderate- to-profound hearing impairment was 19.6% in the total study population and increased with age. Conclusions. It is proposed that the high prevalence rate of farmers’ hearing impairment may be due to excessive workplace noise. To manage farmers’ hearing health, precise evaluations of farmers’ hearing acuity and noise exposure on farms should be conducted. This study might be a stepping-stone to protect farmers’ hearing health.
    Źródło:
    Annals of Agricultural and Environmental Medicine; 2019, 26, 1; 148-153
    1232-1966
    Pojawia się w:
    Annals of Agricultural and Environmental Medicine
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Contamination of soil with heavy metals drained out from abandoned mines in the South-West region of Korea
    Autorzy:
    Kim, S.-D.
    Dho, H.-S.
    Lee, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/207493.pdf
    Data publikacji:
    2015
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    soil pollution
    abandoned mines
    arsenic
    heavy metals
    nickel
    soils
    zinc
    contamination level
    forest regions
    surface soil
    zanieczyszczenie gleby
    zlikwidowane kopalnie
    arsen
    metale ciężkie
    nikiel
    gleby
    cynk
    poziom zanieczyszczeń
    obszary leśne
    powierzchniowe warstwy gleby
    Opis:
    Contamination of soil with heavy metals drained out from twenty eight abandoned mines in the southwest regions of Korea has been investigated. Utilizing various statistical techniques, the goal was to evaluate and analyze pH and the contamination with Arsenic, and the following six heavy metals: cadmium, hydrargyrum, lead, nickel, chromium, and zinc. Contamination levels of heavy metals were determined depending on the depth of the soil. Results indicated that the subsoil and the surface soil both were strongly contaminated with lead and arsenic. Furthermore, the subsoil also contained much nickel. In forest regions, high levels of lead and arsenic, whereas in all regions high levels of zinc have been detected.
    Źródło:
    Environment Protection Engineering; 2015, 41, 3; 61-72
    0324-8828
    Pojawia się w:
    Environment Protection Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Ni Content on the Austenite Stability and Mechanical Properties of Nanocrystalline Fe-Ni Alloy Fabricated by Spark Plasma Sintering
    Autorzy:
    Park, D.
    Oh, S.-J.
    Shon, I.-J.
    Lee, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/352972.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Fe-Ni alloy
    austenite stability
    mechanical properties
    spark plasma sintering
    Opis:
    The mechanical behavior and the change of retained austenite of nanocrystalline Fe-Ni alloy have been investigated by considering the effect of various Ni addition amount. The nanocrystalline Fe-Ni alloy samples were rapidly fabricated by spark plasma sintering (SPS). The SPS is a well-known effective sintering process with an extremely short densification time not only to reach a theoretical density value but also to prevent a grain growth, which could result in a nanocrystalline structures. The effect of Ni addition on the compressive stress-strain behavior was analyzed. The variation of the volume fraction of retained austenite due to deformation was quantitatively measured by means of x-ray diffraction and microscope analyses. The strain-induced martensite transformation was observed in Fe-Ni alloy. The different amount of Ni influenced the rate of the strain-induced martensite transformation kinetics and resulted in the change of the work hardening during the compressive deformation.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1477-1480
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Additives on the Densification Processes and Properties of Silica-Based CMCs
    Autorzy:
    Ko, S.-Y.
    Yong, S.-M.
    Lee, S. J.
    Cheong, D.-I.
    Baek, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/355134.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    ceramic matrix composite
    CMC
    silica
    densification
    mechanical properties
    Opis:
    The effect of additives on the densification behavior and mechanical properties of pure and additive (Zr, B and Mg)-added silica ceramics were investigated for their application to the matrix phase of a silica fiber reinforced silica (SiO2 /SiO2f ) composite. The additives affected the rate of densification and crystallization (or transformation) of the amorphous silica. Among the compositions, pure silica ceramics sintered at 900°C for 1h showed the maximum flexural strength. Based on the results, SiO2 /SiO2f was fabricated by a repeated vacuum-assisted infiltration method followed by the heat treatment at 900°C for 1h. The relative density of the composite was 78.2% with a flexural strength of 22.4 MPa. Fractography revealed that the composite was damaged by strong bonding at the fiber/matrix interface and the fracture of fiber.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1485-1488
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effects of acute lipopolysaccharide-induced toxemia model on some neglected blood parameters
    Autorzy:
    Adam, G.O.
    Lee, H.R.
    Lee, S.J.
    Kim, S.J.
    Kim, G.B.
    Kang, H.S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2087627.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Toxemia
    lipopolysaccharide
    base excess
    pH
    animal model
    Źródło:
    Polish Journal of Veterinary Sciences; 2018, 21, 4; 665-671
    1505-1773
    Pojawia się w:
    Polish Journal of Veterinary Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Allometric scaling of marbofloxacin pharmacokinetics: a retrospective analysis
    Autorzy:
    Yohannes, S.
    Hossain, M.A.
    Kim, J.Y.
    Lee, S.J.
    Kwak, D.M.
    Suh, J.W.
    Park, S.C.
    Powiązania:
    https://bibliotekanauki.pl/articles/31939.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Opis:
    The association between physiologically dependent pharmacokinetic parameters (CLB, T1/2β, Vdss) of marbofloxacin and body weight was studied in eight animal species based on allometric equation Y = aWb, where ‘Y’ is the pharmacokinetic parameter, ‘W’ is body weight, ‘a’ is allometric coefficient (intercept) and ‘b’ is the exponent that describes relation between pharmacokinetic parameter and body weight. The body clearance of marbofloxacin has shown significant (P<0.0001) relation with size (Bwt) in various animal species. However, half-life and volume of distribution were not in association with body weight. Although half-life and volume of distribution were not in a good correlation with body weight, statistically significant association between the body clearance and body weight suggests validity of allometric scaling for predicting pharmacokinetic parameters of marbofloxacin in animal species that have not been studied yet. However further study considering large sample size and other parameters influencing pharmacokinetics of marbofloxacin is recommended.
    Źródło:
    Polish Journal of Veterinary Sciences; 2014, 17, 1
    1505-1773
    Pojawia się w:
    Polish Journal of Veterinary Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of applied frequency on microstructural and electrochemical characteristics of ceramic coating produced on Al-Mg alloy by pulsed plasma electrolytic oxidation
    Autorzy:
    Lee, J.
    Lee, S.
    Kim, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1155322.pdf
    Data publikacji:
    2016-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.16.Pr
    Opis:
    Plasma electrolytic oxidation (PEO) coating is gaining attention as a promising surface treatment technique for lightweight metals and alloys such as Al, Mg and Ti. The coating involves complex interactions among various process parameters including substrate composition, current modes and electrolyte composition. In this study, ceramic coating was produced in silicate based alkaline solution on Al-Mg alloy by pulsed PEO with different applied frequencies (100, 500, 1000, 2000 Hz). The resultant coating was characterized using FE-SEM, EDS and HR-XRD. The electrochemical characteristics of the PEO coating were also investigated in seawater solution. It was found that changing frequency in the PEO process had a prominent effect on both surface and cross-sectional morphology of the coating. The electrochemical studies indicated that the pulsed PEO have improved the corrosion resistance of the Al-Mg substrate. In particular, the applied frequency of 100 Hz has produced one order of magnitude lower corrosion current density than that of the Al-Mg substrate.
    Źródło:
    Acta Physica Polonica A; 2016, 129, 4; 753-758
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sensitizing Effects of Ti Alloying Contents on Damage Behavior of Austenitic Stainless Steel Exposed to Ultrasonic Vibratory Cavitation
    Autorzy:
    Lee, J.
    Kim, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1186947.pdf
    Data publikacji:
    2016-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    47.55.dp
    Opis:
    The cavitation damage characteristics of austenitic stainless steel with different concentrations of Ti were investigated. The microstructure of the alloys was observed with optical microscope to identify its correlation with cavitation resistance. Hardness of the alloys was measured to examine its contribution to cavitation damage. It was found that the microstructure played a more significant role in cavitation damage behavior of austenitic stainless steel with Ti than the hardness. The findings in this study revealed that Ti addition in austenitic stainless steel may present either a beneficial or detrimental effect on cavitation damage behavior, depending on the microstructural characteristics. In particular, Ti content of 1.0% represented the most deteriorated cavitation characteristics due to the formation of relatively coarse precipitates. Therefore, control of Ti concentration is essential for marine application of austenitic stainless steel.
    Źródło:
    Acta Physica Polonica A; 2016, 129, 4; 578-583
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Pre-Sintering on the Diffusion Treatment of HRE for Coercivity Enhancement of a NdFeB Sintered Magnet
    Autorzy:
    Lee, M. W.
    Lee, J. K.
    Jang, T. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/355250.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    grain boundary diffusion process
    GBDP
    NdFeB magnet
    coercivity
    pre-sintering
    Opis:
    We investigated the effect of pre-sintering process on the penetration behavior of Dy in a NdFeB sintered magnet which was grain boundary diffusion treated with Cu/Al mixed Dy source. The pre-sintering of a magnet was performed at 900°C in vacuum and then the pre-sintered body was dipped in the solutions of DyH2, DyH2 + Cu, and DyH2 + Al, respectively. The dipped pre-sintered body were then fully sintered 4 hours at 1060°C followed by a subsequent annealing. The pre-sintering apparently improved the diffusivity of Dy atoms. The penetration of Dy into the magnet extended almost to 2,000 μm from the surface, about four times deeper than that of the normally sintered and diffusion treated one, when the DyH2 + Al solution was used as a Dy source. However, the resulting increase of coercivity was about 4 kOe, somewhat lower than that of the normally treated one, mostly due to excessive oxide formation that hindered to make a continuous Nd-rich grain boundary phase and a core-shell type structure.
    Źródło:
    Archives of Metallurgy and Materials; 2019, 64, 2; 597-601
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Implementation of a Novel Audio Network Protocol
    Autorzy:
    Lee, J.
    Jeon, H.
    Choi, P.
    Kwon, S.
    Lee, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/178062.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    audio mixer
    AoIP
    audio over internet protocol
    DANTE
    SR System
    Opis:
    Recently, the rapid advancement of the IT industry has resulted in significant changes in audio-system configurations; particularly, the audio over internet protocol (AoIP) network-based audio-transmission technology has received favourable evaluations in this field. Applying the AoIP in a certain section of the multiple-cable zone is advantageous because the installation cost is lower than that for the existing systems, and the original sound is transmitted without any distortion. The existing AoIP-based technology, however, cannot control the audio-signal characteristics of every device and can only transmit multiple audio signals through a network. In this paper, the proposed Audio Network & Control Hierarchy Over peer-to-peer (Anchor) system enables all audio equipment to send and receive signals via a data network, and the receiving device can mix the signals of different IPs. Accordingly, it was possible to improve the system-application flexibility by simplifying the audio-system configuration. The research results confirmed that the received audio signals from different IPs were received, mixed, and output without errors. It is expected that Anchor will become a standard for audio-network protocols.
    Źródło:
    Archives of Acoustics; 2018, 43, 4; 637-645
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Immobilization of rambutan (Nephelium lappaceum) peel as a sorbent for Basic Fuchsin removal
    Autorzy:
    Lee, H.-J.
    Ong, S.-T.
    Powiązania:
    https://bibliotekanauki.pl/articles/207651.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    fuchsin
    Fourier transform infrared spectrophotometry
    FTIR
    Nephelium lappaceum
    fuksyna
    spektroskopia w podczerwieni z transformatą Fouriera
    Opis:
    The potential of rambutan (Nephelium lappaceum) peel as a low-cost adsorbent in an immobilized condition to remove Basic Fuchsin from aqueous solution was studied. The effect of initial dye concentration, contact time, pH and adsorbent dosage for the dye removal was studied at room temperature (26±2 °C). Infrared spectrum of rambutan peel indicates the presence of C–O, –OH and C=C functional groups. The adsorption rate was found to be high at the first 30 min and the process reached equilibrium after 3 h with more than 80% of dye being removed. The uptake of Basic Fuchsin was more promising at pH slightly above 7. The study of sorption model and kinetic model showed that the adsorption of Basic Fuchsin on rambutan peel conformed to the Freundlich isotherm and pseudo-second order kinetics with a high correlation coefficient, R,sup>2 > 0.98. This indicates the Basic Fuchsin adsorbs chemically on the heterogeneous surface of rambutan peel. The maximum adsorption capacity determined from the Langmuir isotherm was 108.696 mg/g. It seems that rambutan peel has the potential to substitute activated carbon as an alternative low-cost adsorbent in the treatment of the dye effluent.
    Źródło:
    Environment Protection Engineering; 2017, 43, 1; 169-181
    0324-8828
    Pojawia się w:
    Environment Protection Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    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
    Artykuł
    Tytuł:
    Crystallization Behavior of Zr62Al8Ni13Cu17 Metallic Glass
    Autorzy:
    Jo, M. S.
    Lee, J. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/353070.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    metallic glass
    crystallization
    kinetics
    amorphous
    Zr-based
    Opis:
    The crystallization behavior has been studied in Zr62Al8Ni13Cu17 metallic glass alloy. The Zr62Al8Ni13Cu17 metallic glass crystallized through two steps. The fcc Zr2Ni phase transformed from the amorphous matrix during first crystallization and then the Zr2Ni and residual amorphous matrix transformed into a mixture of tetragonal Zr2Cu and hexagonal Zr6Al2Ni phases. Johnson- Mehl-Avrami analysis of isothermal transformation data suggested that the formation of crystalline phase is primary crystallization by diffusion-controlled growth.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1023-1026
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Premixed combustion of acetylene-hydrogen fuel mixtures for thermodynamic state generation in a constant volume combustion vessel
    Autorzy:
    Johnson, S.
    Nesbitt, J.
    Lee, S. -Y.
    Naber, J. D.
    Powiązania:
    https://bibliotekanauki.pl/articles/242374.pdf
    Data publikacji:
    2009
    Wydawca:
    Instytut Techniczny Wojsk Lotniczych
    Tematy:
    combustion engine
    diesel engine
    combustion processes
    pressure vessel
    preborn
    Opis:
    Flammability limits and flame speeds of dilute-lean fuel mixtures of hydrogen (H2) and acetylem premixed with oxygen (02) and nitrogen (N2) were examined with a detailed kinetics model. These mixtures are used in a preburn in a constant volume combustion vessel to create elevated temperatures and pressures with gas compositions that represent the thermodynamic state in a diesel engine combustion chamber at fuel injection and auto ignition. A mixture of hydrogen and acetylene with combined atomic hydrogen to carbon ratio (HCR) of 1.85 was used to match that of typical diesel fuel and results are shown in comparison to a previously used mixture with a HCR of 1.17. The lower flammability limit (LFL) of the HCR 1.85 fuel mixture was found at an equivalence ratio of 0.235, while flame speed and adiabatic combustion temperatures were also predicted for post preburn product oxygen levels between O and 21 percent. Flame speeds were shown to decrease with a reduction in oxygen concentration, an increase in nitrogen dilution, while combustion temperatures increased over most of this range. Trends for this relation of flame speed and temperature are presented and a new premixed fuel mixture with an HCR of 1.85 is proposed.
    Źródło:
    Journal of KONES; 2009, 16, 2; 199-208
    1231-4005
    2354-0133
    Pojawia się w:
    Journal of KONES
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Boundary element modelling of wave diffraction by interaction with wave-offshore structure and dredged region
    Autorzy:
    Kim, S. D.
    Lee, H. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/259525.pdf
    Data publikacji:
    2010
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    Submarine pit
    Green function
    boundary integral approach
    breakwater
    Opis:
    The purpose of this study is to estimate the wave height at the front face of breakwater (Refracted breakwater and Straight breakwater), when dredging like the submarine pit is performed in the distant offshore from outer breakwater. The wave field of the problem is considered to be two dimensional planes and the configuration of the pit region is designated by a single horizontal long-rectangular system. The numerical approach uses the Green function based on the boundary integral approach. The results of the present numerical works are illustrated by applying the normal and inclined incidence. It is shown that in the case of normal incidence, the ratio of wave height reduction at the front face of both types of breakwaters is approximately more than 20% due to the effect of the submarine pit on the sea bed. Furthermore, regardless of the type of breakwater and the difference in incident wave angles, the ratio of wave height was shown to be reduced.
    Źródło:
    Polish Maritime Research; 2010, 2; 67-71
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Morphology Change Of Si Deposit In Molten Salt Electrorefining
    Zmiana morfologii osadu Si podczas elektrorafinacji w stopionych solach
    Autorzy:
    Ryu, H. Y.
    Kwon, S. C.
    Han, M. H.
    An, Y. S.
    Lee, J. S.
    Lee, J. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/354346.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    molten salt
    silicon
    morphology
    electrorefining
    current density
    sól stopiona
    krzem
    morfologia
    elektrorafinacja
    gęstość prądu
    Opis:
    The effects of processing parameters on the morphology change in a Si deposit recovered by means of molten salt electrorefining are evaluated using electrochemical techniques such as cyclic voltammetry and chronopotentiometry at 800°C. It was found that concentration of K2SiF6 and current density were important parameters in determining deposit size. Higher concentrations of K2SiF6 were effective in coarsening the silicon deposit and decreasing the cell potential. Silicon nanofiber was recovered at 5 wt% of K2SiF6 whereas dense particles were prepared at 30 and 50 wt% of K2SiF6. The morphology of the Si deposit was determined by the concentration of Si in the electrolyte which is related to the formation of crystal and growth of Si. The formation mechanism of the Si deposit was interpreted by using high resolution TEM as well as electrochemical properties.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1491-1497
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication of Mo-Si-B Intermetallic Compound Powders Under Different Heat Treatment Conditions
    Autorzy:
    Park, J. H.
    Lee, S.
    Kim, D.
    Kim, Y.
    Yang, S. H.
    Lee, S. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/353369.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Mo-Si-B alloys
    intermetallic compounds
    reitveld refinement
    T2 phase
    A15 phase
    Opis:
    In this research, we investigated the effects of reduction atmospheres on the creation of the Mo-Si-B intermetallic compounds (IMC) during the heat treatments. For outstanding anti-oxidation and elevated mechanical strength at the ultrahigh temperature, we fabricated the uniformly dispersed IMC powders such as Mo5SiB2 (T2) and Mo3Si (A15) phases using the two steps of chemical reactions. Especially, in the second procedure, we studied the influence of the atmospheres (e.g. vacuum, argon, and hydrogen) on the synthesis of IMCs during the reduction. Furthermore, the newly produced IMCs were observed by SEM, XRD, and EDS to identify the phase of the compounds. We also calculated an amount of IMCs in the reduced powders depending on the atmosphere using the Reitveld refinement method. Consequently, it is found that hydrogen atmosphere was suitable for fabrication of IMC without other IMC phases.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1509-1512
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Microstructure and Magnetic Properties of NdFeB Sintered Magnets Diffusion-Treated with Cu/Al Mixed Dyco Alloy-Powder
    Autorzy:
    Lee, M.-W.
    Bae, K.-H.
    Lee, S.-R.
    Kim, H.-J.
    Jang, T.-S.
    Powiązania:
    https://bibliotekanauki.pl/articles/353351.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Nd-Fe-B sintered magnets
    grain boundary diffusion process
    low melting point element
    DyCo alloy-powder diffusion
    Opis:
    We investigated the microstructural and magnetic property changes of DyCo, Cu + DyCo, and Al + DyCo diffusion-treated NdFeB sintered magnets. The coercivity of all diffusion treated magnet was increased at 880ºC of 1st post annealing(PA), by 6.1 kOe in Cu and 7.0 kOe in Al mixed DyCo coated magnets, whereas this increment was found to be relatively low (3.9 kOe) in the magnet coated with DyCo only. The diffusivity and diffusion depth of Dy were increased in those magnets which were treated with Cu or Al mixed DyCo, mainly due to comparatively easy diffusion path provided by Cu and Al because of their solubility with Ndrich grain boundary phase. The formation of Cu/Al-rich grain boundary phase might have enhanced the diffusivity of Dy-atoms. Moreover, relatively a large number of Dy atoms reached into the magnet and mostly segregated at the interface of Nd2 Fe14 B and grain boundary phases covering Nd2 Fe14 B grains so that the core-shell type structures were developed. The formation of highly anisotropic (Nd, Dy)2Fe14B phase layer, which acted as the shell in the core-shell type structure so as to prevent the reverse domain movement, was the cause of enhancing the coercivity of diffusion treated NdFeB magnets. Segregation of cobalt in Nd-rich TJP followed by the formation of Co-rich phase was beneficial for the coercivity enhancement, resulting in the stabilization of the metastable c-Nd2O3 phase.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1263-1266
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Characterization of Cu and Ni Nano-Fluids Synthesized by Pulsed Wire Evaporation Method
    Autorzy:
    Kim, H.-S.
    Yilmaz, F.
    Dharmaiah, P.
    Lee, D.-J
    Lee, T.-H.
    Hong, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/356475.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    pulsed wire evaporation
    nanofluid
    Cu
    Ni
    suspension stability
    dispersibility
    Opis:
    In the present work, Cu and Ni nanofluids were synthesized using the pulsed wire evaporation (PWE) method in the different aqueous medias, namely (ethanol and ethylene glycol), and the effects of the aqueous media on the dispersion state, stability, and particle size of nanoparticles were studied. The size and morphology of synthesized nano-particles were investigated by transmission electron microscopy (TEM). Also, the dispersion stability of the nanofluids was evaluated by turbiscan analysis. The TEM results showed that the nano-particles were spherical in shape, and the average particle size was below 100 nm. The average particle size of the Cu nano-particles was smaller than that of Ni, which was attributed to a difference in the specific sublimation energy of the elements. Moreover, ethylene glycol (EG) exhibited higher suspension stability than ethanol. Finally, the dispersion stability of Cu@EG displayed the highest value due to lower particle size and greater viscosity.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 999-1004
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Growth Break before Capping on Photoluminescence Dynamics of CdSe/ZnSe Self-Assembled Quantum Dots
    Autorzy:
    Nowak, S.
    Suffczyński, J.
    Goryca, M.
    Kossacki, P.
    Gaj, J.
    Lee, S.
    Furdyna, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1811967.pdf
    Data publikacji:
    2008-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    78.55.Et
    78.67.Hc
    81.07.Ta
    Opis:
    Influence of growth breaks before capping of CdSe self-assembled quantum dot layers on photoluminescence dynamics was examined in three samples. Short (5s) break resulted only in a small blue shift, caused probably by partial strain relaxation and/or Zn interdiffusion. Long (20 min) break induced a strong broadening and red shift of the spectra, combined with a dramatic slow down of the photoluminescence decays. The main result of the long break was identified as introduction of defects (impurities), which generate local electric fields and act as traps of photogenerated carriers.
    Źródło:
    Acta Physica Polonica A; 2008, 114, 5; 1267-1271
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    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
    Artykuł
    Tytuł:
    Vibrational Properties of Sundatang Soundboard
    Autorzy:
    Batahong, R. Y.
    Dayou, J.
    Wang, S.
    Lee, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/176904.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    sundatang
    frequency response function
    impact testing
    mode shape
    Opis:
    This paper presents the measurement of vibrational properties of sundatang soundboard. Sundatang is a plucked stringed traditional musical instrument that is popular among the Kadazandusun communities in Sabah, Malaysia. The vibrational properties of the soundboard are measured using CADA-X impact hammering system in a condition where the instrument is without any string. There are two types of sundatang used in this study; one made from acacia and the other from vitex wood. In this measurement, frequency response functions (FRFs) and modal parameters of the top plate and back plate of this instrument are obtained. It is found that in free edge, fundamental frequency of both plates of acacia sundatang is greater than the vitex sundatang in a range of 112 Hz to 230 Hz. However, in clamped edge (attached to its ribs), it was modified to a lower frequency and closer to each other in the range of 55 Hz to 59 Hz. Another finding is the detection of the excitation of similar mode shape at different resonance frequencies. This phenomenon is termed as Different State of Mode (DSM) which is observed may be because the number of testing points is not enough. Findings of this study provide important information to the study of quality development of this instrument.
    Źródło:
    Archives of Acoustics; 2014, 39, 2; 177-187
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    System Identification from Multiple-Trial Data Corrupted by Non-Repeating Periodic Disturbances
    Autorzy:
    Phan, M. Q.
    Longman, R. W.
    Lee, S. C.
    Lee, J. W.
    Powiązania:
    https://bibliotekanauki.pl/articles/908209.pdf
    Data publikacji:
    2003
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    automatyka
    robotyka
    system identification
    disturbance identification
    iterative learning control
    repetitive control
    interaction matrix
    Opis:
    Iterative learning and repetitive control aim to eliminate the effect of unwanted disturbances over repeated trials or cycles. The disturbance-free system model, if known, can be used in a model-based iterative learning or repetitive control system to eliminate the unwanted disturbances. In the case of periodic disturbances, although the unknown disturbance frequencies may be the same from trial to trial, the disturbance amplitudes, phases, and biases do not necessarily repeat. Furthermore, the system may not return to the same initial state at the end of each trial before starting the next trial. In spite of these constraints, this paper shows how to identify the system disturbance-free dynamics from disturbance-corrupted input-output data collected over multiple trials without having to measure the disturbances directly. The system disturbance-free model can then be used to identify the disturbances as well, for use in learning or repetitive control. This paper represents the first extension of the interaction matrix approach to the multiple-trial environment of iterative learning control.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2003, 13, 2; 185-192
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analyzing the factors affecting the safe maritime navigation for training apprentice officers
    Autorzy:
    Lee, M. K.
    Park, S. W.
    Park, Y. S.
    Park, M. J.
    Lee, E. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/116471.pdf
    Data publikacji:
    2019
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    maritime education and training (MET)
    safe maritime navigation
    training apprentice officers
    simulation based training
    ship maneuver simulation
    navigational safety
    safety at sea
    apprentice officer
    Opis:
    One of the primary factors that affect the safe maritime navigation is the insufficient experience and skill of an apprentice officer, which may be improved using simulation-based training by ensuring operational efficiency. This study aims to determine appropriate factors for achieving effective and intensive simulation-based training of apprentice officers and present the guidelines for such a training scheme. Initially, a marine traffic risk model, which interprets and accurately measures the risk of collision with other vessels, is analyzed to derive the most influential factors in safe navigation. Subsequently, simulation experiments are conducted by applying machine learning to verify the required safe navigation factors for effectively training the apprentice officers. As a result of the above analysis, it was confirmed that the factor affecting safe maritime navigation was the distance from other vessels. Finally, the differences between these distances in the simulations are analyzed for both the apprentice officers and the experienced officers, and the guidelines corresponding to both these cases are presented. This study has the limitation because of the difference between the ship maneuver simulation and the actual ship navigation. This can be resolved based on the results of this study, in combination with the actual navigation data.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 2; 393-399
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Biological Evaluation of Anodized Biodegradable Magnesium-Calcium Alloys
    Autorzy:
    Kim, J.
    Lee, J.
    Lee, K.
    Park, S.
    Lim, H.
    Park, C.
    Bae, J.
    Yun, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398763.pdf
    Data publikacji:
    2016-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    87.85.jj
    87.85.J-
    Opis:
    The objective of this study was to evaluate the biocompatibility of studied binary magnesium-calcium (Mg-Ca) alloys for biodegradable intraosseous implants. Mg is necessary for health and is a non-toxic biodegradable material that decomposes naturally in the body. Nevertheless, Mg has been implicated in problems including diminished physical properties and corrosion resistance when degradation is too rapid prior to bone healing. This study has explored the effect of Ca on the corrosion resistance and biological evaluation after anodizing treatment with different contents of Ca alloy. Binary Mg-0.5Ca, Mg-1Ca and Mg-5Ca alloys were prepared by the casting method under an argon atmosphere and cut into disc-shaped pieces. Pure Mg alloy was used as the control. Anodic oxidation was performed for 15 minutes at a voltage of 120 V using an electrolyte solution containing Ca gluconate, sodium hexametaphosphate, and sodium hydroxide at room temperature. Corrosion resistance was analyzed using a corrosion tester. After a hydrogen evolution test, the surface pattern and phase changes were observed on a scanning electron microscop (SEM) and energy dispersive spectroscop (EDS). Microscopic evaluation of the adhesion and cell biological functions of Mg was conducted by observing the response of human fetal osteoblastic 1.19 cells with regard to changes in surface film properties, depending on the amount of Ca. Our results support the view that in Mg-xCa alloys (x=0.5, 1, 5 wt.%) treated using anodic oxidation, the increasing Ca content controls the rate of decomposition and improves corrosion resistance.
    Źródło:
    Acta Physica Polonica A; 2016, 129, 4; 728-735
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of Localized Electric Field in the Type-II InAs/GaAsSb/GaAs Structure
    Autorzy:
    Lee, S.
    Kim, J.
    Yoon, S.
    Kim, Y.
    Honsberg, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398577.pdf
    Data publikacji:
    2016-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    78.66.Fd
    78.40.-q
    73.40.Lq
    73.50.Pz
    Opis:
    The effect of localized electric field (F) was investigated in the type-II InAs/GaAsSb/GaAs structures. To compare type-I to type-II, two types of samples with different Sb contents was grown by molecular beam epitaxy, whose Sb contents are 3% (type-I) and 16% (type-II), respectively. In the both samples, we performed excitation power dependent-photoreflectance at 10 K and the result showed that the period of the Franz-Keldysh oscillation, revealed above the band gap $(E_{g})$ of GaAs, was broadened in the only type-II system, which means that F was also increased because it is proportional to the period of the Franz-Keldysh oscillation while the period of the Franz-Keldysh oscillations stayed unchanged in type-I system. This phenomenon is explained by that the F was affected by the band bending effect caused by the spatially separated photo-excited carriers in the interface between GaAsSb and GaAs. The F changed linearly as a function of square root of excitation power as expected for the F. Moreover, F was calculated using fast Fourier transform method for a qualitative analysis, which is in a good agreement with the theory of triangular well approximation.
    Źródło:
    Acta Physica Polonica A; 2016, 130, 5; 1213-1216
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Time and Temperature Dependent Damage Characteristics of 5083 Al Alloy under Cavitation-Corrosion Condition
    Autorzy:
    Lee, S.
    Han, M.
    Jeong, J.
    Kim, M.
    Kim, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398766.pdf
    Data publikacji:
    2016-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    47.55.dp
    82.45.Bb
    Opis:
    Continuous efforts to construct high-speed and lightweight ship have been made to reduce cost against growing oil prices. In this context, aluminum has received attention as an alternative material for steel, for small and medium-sized ships. In an effort to extend service life of aluminum, various researches have been attempting to improve the corrosion resistance and anti-corrosion characteristics by applying heat treatment and alloying. The material, however, has a high probability of being attacked by corrosion and erosion, caused by high ship speed in severe marine environments. Cavitation damage is dependent on several important factors, such as shape of objects, surface roughness, rotation speed, fluid pressure and velocity. Vapor pressure, density and surface tension of fluid are also taken into account. In this study, an electrochemical cavitation erosion-corrosion experiment was conducted as a function of solution temperature and applied amplitude for 5083-O aluminum alloy used commercially as a hull material for a small sized ship. The result of the experiment revealed that the damage was accelerated due to synergistic effect of corrosion and erosion as the solution temperature was elevated, and that the weight loss showed a steady increase with increasing time of cavitation.
    Źródło:
    Acta Physica Polonica A; 2016, 129, 4; 747-752
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Integrated plant and pathogen‘omics approaches to understanding fungal diseases of wheat
    Autorzy:
    Rudd, J.J.
    Lee, W.-S.
    Hammond-Kosack, K.
    Kanyuka, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/81017.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    conference
    plant infection
    fungal disease
    wheat
    septoria tritici blotch
    intercellular pathogen
    leaf damage
    RNA sequence
    functional genomics
    Źródło:
    BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 3
    0860-7796
    Pojawia się w:
    BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Point-Contact Spectroscopy of Superconducting $MgCNi_3$ Single Crystals
    Autorzy:
    Pribulová, Z.
    Szabó, P.
    Kačmarčík, J.
    Samuely, P.
    Jang, D.
    Lee, H.
    Lee, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813611.pdf
    Data publikacji:
    2008-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    74.50.+r
    Opis:
    The first point-contact spectroscopy measurements on $MgCNi_3$ single crystals of very good quality are presented. The measurements have been performed in the temperature range from 1.5 K up to 10 K and at magnetic fields up to 6 T. The superconducting energy gap Δ of the system is found to be scattered between 1 and 1.2 meV which gives the 2Δ/k $T_c$ ratio between BCS weak-coupling value of ~3.5 and a strong coupling of about 4.2. The excess current evaluated in magnetic field indicates the presence of a single energy gap.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 1; 215-218
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Variable-Focus Fluid Lens Using an Electromagnetic Actuator
    Autorzy:
    Lee, J.
    Park, K.
    Choi, J.
    Kim, H.
    Kong, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1399681.pdf
    Data publikacji:
    2013-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    85.85.+j
    42.79.Bh
    Opis:
    A variable-focus fluid lens controlled by an electromagnetic actuator and its characteristics are presented in this paper. The repulsive force between an NdFeB magnet and a solenoid through electromagnetic induction causes deflections in the elastomeric membranes integrated in the lens resulting in a focal-length change. The controllability of the focal length of the fabricated lens with an aperture size of 2 mm was approximately from infinity to 15 mm (with input current of 100 mA). The actuator including the solenoid was carefully designed to avoid thermal crosstalk of the lens fluid and magnet from the electromagnetic induction of the solenoid. The settling time to form a convex shape of the lens membrane was approximately 2.5 ms at an input current of 20 mA.
    Źródło:
    Acta Physica Polonica A; 2013, 123, 2; 202-204
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    High Temperature Oxidation Property of SiC Coating Layer Fabricated by Aerosol Deposition Process
    Autorzy:
    Ham, G.-S.
    Kim, S.-H.
    Park, J.-Y.
    Lee, K.-A.
    Powiązania:
    https://bibliotekanauki.pl/articles/352142.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    silicon carbide
    aerosol deposition
    coating
    high temperature oxidation
    Opis:
    This study investigated the high temperature oxidation property of SiC coated layer fabricated by aerosol deposition process. SiC coated layer could be successfully manufactured by using pure SiC powders and aerosol deposition on the Zr based alloy in an optimal process condition. The thickness of manufactured SiC coated layer was measured about 5 μm, and coating layer represented high density structure. SiC coated layer consisted of α-SiC and β-SiC phases, the same as the initial powder. The initial powder was shown to have been crushed to the extent and was deposited in the form of extremely fine particles. To examine the high temperature oxidation properties, oxidized weight gain was obtained for one hour at 1000°C by using TGA. The SiC coated layer showed superior oxidation resistance property than that of Zr alloy (substrate). The high temperature oxidation mechanism of SiC coated layer on Zr alloy was suggested. And then, the application of aerosol deposited SiC coated layer was also discussed.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1347-1351
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    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
    Artykuł
    Tytuł:
    The effect of patterns on image-based modelling of texture-less objects
    Autorzy:
    Hafeez, J.
    Jeon, H.-J.
    Hamacher, A.
    Kwon, S.-C.
    Lee, S.-H.
    Powiązania:
    https://bibliotekanauki.pl/articles/221814.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    structure-from-motion
    feature detection
    patterns analysis
    3D reconstruction
    surface comparison
    Opis:
    The task of generating fast and accurate three-dimensional (3D) models of objects or scenes through a sequence of non-calibrated images is an active field of research. The recent development in algorithm optimization has resulted in many automatic solutions that can provide an accurate 3D model from texture-full objects. Structure-from-motion (SfM) is an image-based method that uses discriminative point-based feature identifier, such as SIFT, to locate feature points in the images. This method faces difficulties when presented with the objects made of homogenous or texture-less surfaces. To reconstruct such surfaces a well-known technique is to apply an artificial variety by covering the surface with a random texture pattern prior to the image capturing process. In this work, we designed three series of image patterns which are tested based on the contrast and density ratio which increases from the first to the last pattern within the same series. The performance of the patterns is evaluated by reconstructing the surface of a texture-less object and comparing it with the true data. Using the best-found patterns from the experiments, a 3D model of a Moai statue is reconstructed. The experimental results demonstrate that the density and structure of a pattern highly affects the quality of the reconstruction.
    Źródło:
    Metrology and Measurement Systems; 2018, 25, 4; 755-767
    0860-8229
    Pojawia się w:
    Metrology and Measurement Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication Of Zn4Sb3 Alloys By A Combination Of Gas-Atomization And Spark Plasma Sintering Processes
    Wytwarzanie i konsolidacja proszków stopowych zn4sb3 przez kombinację procesów atomizacji gazowej i spiekania
    Autorzy:
    Dharmaiah, P.
    Kim, H.-S.
    Lee, L. H.
    Hong, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/355894.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    gas atomization
    microstructure
    spark plasma sintering (SPS)
    X-ray diffraction
    atomizacja gazowa
    mikrostruktura
    SPS
    spiekanie plazmowe
    analiza rentgenowska (XRD)
    Opis:
    In this study, single phase polycrystalline Zn4Sb3 as well as 11 at.% Zn-rich Zn4Sb3 alloy having ε-Zn4Sb3 (majority phase) and Zn (minority phase) phases bulk samples produced by gas-atomization and subsequently consolidated by spark plasma sintering (SPS) process. The crystal structures were analyzed by X-ray diffraction (XRD) and cross-sectional microstructure were observed by the scanning electron microscopy (SEM). The internal grain microstructure of 11at.% Zn-rich Zn4Sb3 powders shows lamellar structure. Relative density, Vickers hardness and crack lengths were measured to investigate the effect of sintering temperature of Zn4Sb3 samples which are sintered at 653, 673 and 693 K. Relative density of the single phase bulk Zn4Sb3 sample reached to 99.2% of its theoretical density. The micro Vickers hardness of three different sintering temperatures were found around 2.17 – 2.236 GPa.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1417-1421
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An Experimental Study on the Determination of Optimal Lubrication Conditions in a High-Speed Spindle
    Autorzy:
    Park, S.-J.
    Hwang, Y.-K
    Lee, C.-M
    Powiązania:
    https://bibliotekanauki.pl/articles/971161.pdf
    Data publikacji:
    2009
    Wydawca:
    Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
    Tematy:
    optimal lubrication condition
    oil-air lubrication
    high speed spindle
    Opis:
    The heat generation inside spindles becomes a major factor that limits the allowable maximum rotational speed in machine tools and decreases the cutting quality. It is necessary to accurately estimate the temperature distribution in spindles caused by the heat generation in bearings and its heat transfer characteristics in order to perform the high-speed and high-precision in high-speed spindles. In addition, an accurate correction process is required according to the results of the estimation through investigating the thermal deformation error. A commercial program, MINITAB, was used to establish an experiment plan that analyzes the heat generation characteristics of the spindle system according to the operation and lubrication conditions of the spindle. Also, the change in the outer ring temperature of bearings was measured according to the experimental plan. After establishing a response surface model using the results of the experiment, the estimation equation of the quadratic polynomial model was proposed for determining the optimal lubrication condition. A verification experiment was applied to verify the accuracy of the experimental equation determined by the estimated regression model and the experimental value used in the estimation of the regression model.
    Źródło:
    Journal of Machine Engineering; 2009, 9, 2; 106-113
    1895-7595
    2391-8071
    Pojawia się w:
    Journal of Machine Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Aluminum Oxide Formation On Fecral Catalyst Support By Electro-Chemical Coating
    Powstawanie tlenku glinu na nośniku katalizatora FeCrAl przez osadzanie elektrochemiczne
    Autorzy:
    Yang, H. S.
    Jang, D. H.
    Lee, K. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/355942.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    FeCrAl
    catalyst support
    aluminum oxide formation
    PEO
    plasma electrolytic oxidation
    electrochemical coating
    nośnik katalizatora
    tlenek glinu
    plazmowe utlenianie elektrolityczne
    elektrochemiczne osadzanie
    Opis:
    FeCrAl is comprised essentially of Fe, Cr, Al and generally considered as metallic substrates for catalyst support because of its advantage in the high-temperature corrosion resistance, high mechanical strength, and ductility. Oxidation film and its adhesion on FeCrAl surface with aluminum are important for catalyst life. Therefore various appropriate surface treatments such as thermal oxidation, Sol, PVD, CVD has studied. In this research, PEO (plasma electrolytic oxidation) process was applied to form the aluminum oxide on FeCrAl surface, and the formed oxide particle according to process conditions such as electric energy and oxidation time were investigated. Microstructure and aluminum oxide particle on FeCrAl surface after PEO process was observed by FE-SEM and EDS with element mapping analysis. The study presents possibility of aluminum oxide formation by electro-chemical coating process without any pretreatment of FeCrAl.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1503-1506
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Experiments and simulations on the possibility of radiative contraction/collapse in the PF-1000 plasma focus
    Autorzy:
    Akel, M.
    Cikhardt, J.
    Kubes, P.
    Kunze, H.-J.
    Lee, S.
    Paduch, M.
    Saw, S. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/147275.pdf
    Data publikacji:
    2016
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    plasma focus
    radiative collapse
    radiation losses
    simulations
    Opis:
    Experimental studies of discharges in the plasma focus facility with neon filling and respective numerical simulations employing the radiative Lee code are reported. The pinch currents exceed the Pease-Braginskii current, which indicates that radiative losses are larger than heating and that contraction of the formed plasma should occur. Both of these effects were indeed observed. Parallel numerical simulations were crucial for the identifi cation of such an effect.
    Źródło:
    Nukleonika; 2016, 61, 2; 145-148
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication of AZ31/CNT Surface Nano-composite by Double-pass Friction Stir Processing
    Autorzy:
    Kim, J. Y.
    Hwang, J.-W.
    Kim, H. Y.
    Lee, S. M.
    Jung, W.-S.
    Byeon, J.-W.
    Powiązania:
    https://bibliotekanauki.pl/articles/355624.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    surface modification
    Double-pass Friction Stir Processing
    AZ31
    composite
    CNT
    Opis:
    Double-pass Friction Stir Processing (FSP) was applied to fabricate an AZ31/CNT nano-composite for surface hardening of lightweight structural components. The effects of double-pass FSP as well as groove depth (i.e., volume fraction of CNT) on the CNT distribution, dynamically recrystallized grain size, and resulting microhardness were studied. Double-pass FSP was performed for the CNT-filled plate-type specimen with different groove depths of 2, 3, and 4 mm. By applying double-pass FSP, the average size of CNT clusters decreased, implying a more homogeneous distribution. Compared with the FSPed specimen without CNT, grain size was refined from 19 μm to 3 μm and microhardness increased from 52 Hv to 83 Hv (i.e., 71% increase).
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1039-1042
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect Of DyMn Alloy-Powder Addition On Microstructure And Magnetic Properties Of NdFeB Sintered Magnets
    Wpływ dodatku proszku DyMn na mikrostrukturę i właściwości magnetyczne spiekanych magnesów NdFeB
    Autorzy:
    Lee, M.-W.
    Dhakal, D. R.
    Kim, T. H.
    Lee, S. R.
    Kim, H. J.
    Jang, T. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/357010.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Nd-Fe-B sintered magnets
    DyMn-alloy powder
    coercivity
    low melting point element
    magnesy spiekane
    proszek DyMn
    koercja
    elementy o niskiej temperaturze topnienia
    Opis:
    Micostructural change and corresponding effect on coercivity of a NdFeB sintered magnet mixed with small amount of DyMn powder was investigated. In the sintered magnet mixed with the DyMn alloy-powder Dy-rich shell was formed at outer layer of the main grains, while Mn was mostly concentrated at Nd-rich triple junction phase (TJP), lowering melting temperature of the Nd-rich phase that eventually improved the microstructural characteristics of the gain boundary phase. The coercivity of a magnet increased more than 3.5 kOe by the mixing of the DyMn alloy-powder.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1407-1409
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Microstructure Evolution of Ni-Based ODS Superalloy Powders During Horizontal Rotary Ball Milling
    Autorzy:
    Lee, H.-E.
    Kim, Y. S.
    Park, J. K.
    Oh, S.-T.
    Powiązania:
    https://bibliotekanauki.pl/articles/355552.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    high energy ball milling
    Ni-base ODS superalloy
    particle and crystalline size
    microstructure
    Opis:
    Microstructure evolution of Ni-based oxide dispersion-strengthened alloy powders with milling time is investigated. The elemental powders having a nominal composition of Ni-15Cr-4.5Al-4W-2.5Ti-2Mo-2Ta-0.15Zr-1.1Y2O3 in wt % were ball-milled by using horizontal rotary ball milling with the change of milling velocity. Microstructure observation revealed that large aggregates were formed in the early stages of ball milling, and further milling to 5 h decreased particle size. The average crystalline size, estimated by the peak broadening of XRD, decreased from 28 nm to 15 nm with increasing milling time from 1 h to 5 h. SEM and EPMA analysis showed that the main elements of Ni and Cr were homogeneously distributed inside the powders after ball milling of 5 h.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1253-1255
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Development of Ship Watch Keeping Supporting Aids
    Autorzy:
    Im, N.
    Kim, E. K.
    Han, S. H.
    Jeong, J. S.
    Lee, S. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/117602.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Ship Watchkeeping
    Deck Officers
    Navigation Visual Supporting System
    Intelligent Technology
    Dangerous Floating Objects
    Binocular Telescope
    laser distance measuring unit
    Sea Trial Test
    Opis:
    This study deals with the development of ship watch keeping supporting aids that will be useful for ship deck officers in recognizing navigational harmful obstacles such as sea marks and small floating objects on the sea. The developed watch keeping supporting aids is made up of four components; a composite video sensor to produce video signal, a laser distance measuring part, a Pan/Tilt part and a central control part. The system was installed in a ship in order to verify its performance of the recognition ability on the sea. The comparison was made between the recognition ability of the system and that of watch keeping deck officers’. The image from the watch keeping supporting system was found to be more recognizable than that of a binocular telescope within a 5 km distance. The newly suggested system is expected to be used to recognize small dangerous floating objects more easily when navigation deck officers have a duty of watch keeping for navigation especially near harbor area.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2013, 7, 4; 501-506
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Recovery Of Electrodic Powder From Spent Lithium Ion Batteries (LIBs)
    Odzysk proszku elektrodowego z zużytych akumulatorów litowo-jonowych
    Autorzy:
    Shin, S. M.
    Jung, G. J.
    Lee, W-J.
    Kang, C. Y.
    Wang, J. P.
    Powiązania:
    https://bibliotekanauki.pl/articles/354084.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    lithium ion battery
    electrodic powder
    cobalt
    lithium
    thermal treatment
    bateria litowo-jonowa
    proszek elektrodowy
    kobalt
    lit
    obróbka termiczna
    Opis:
    This study was focused on recycling process newly proposed to recover electrodic powder enriched in cobalt (Co) and lithium (Li) from spent lithium ion battery. In addition, this new process was designed to prevent explosion of batteries during thermal treatment under inert atmosphere. Spent lithium ion batteries (LIBs) were heated over the range of 300°C to 600°C for 2 hours and each component was completely separated inside reactor after experiment. Electrodic powder was successfully recovered from bulk components containing several pieces of metals through sieving operation. The electrodic powder obtained was examined by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and atomic absorption spectroscopy (AA) and furthermore image of the powder was taken by scanning electron microscopy (SEM). It was finally found that cobalt and lithium were mainly recovered to about 49 wt.% and 4 wt.% in electrodic powder, respectively.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1145-1149
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Surfactant Addition on Bi2Te3 Nanostructures Synthesized by Hydrothermal Method
    Autorzy:
    Dharmaiah, P.
    Lee, C. H.
    Madavali, B.
    Hong, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/351609.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    bismuth telluride
    hydrothermal synthesis
    spark plasma sintering
    thermoelectric materials
    X-ray diffraction
    Opis:
    In the present work, we have prepared Bi2Te3 nanostructures with different morphologies such as nano-spherical, nanoplates and nanoflakes obtained using various surfactant additions (EG, PVP, and EDTA) by a hydrothermal method. The shape of the nanoparticles can be controlled by addition of surfactants. The samples were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that the minority BiOCl phase disappears after maintained pH at 10 with EG as surfactant. SEM bulk microstructure reveals that the sample consists of fine and coarse grains. Temperature dependence of thermoelectric properties of the nanostructured bulk sample was investigated in the range of 300-450K. The presence of nanograins in the bulk sample exhibits a reduction of thermal conductivity and less effect on electrical conductivity. As a result, a figure of merit of the sintered bulk sample reached 0.2 at 400 K. A maximum micro Vickers hardness of 102 Hv was obtained for the nanostructured sample, which was higher than the other reported results.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1005-1010
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    AC Microcalorimetry of Superconducting $MgCNi_3$ Single Crystals
    Autorzy:
    Kačmarčík, J.
    Pribulová, Z.
    Samuely, P.
    Marcenat, C.
    Klein, T.
    Jang, D.
    Lee, H.
    Lee, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813689.pdf
    Data publikacji:
    2008-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    74.70.Ad
    74.25.Bt
    Opis:
    The low-temperature specific heat of single-crystal samples of superconducting $MgCNi_3$ with typical dimensions 200 μm were measured for the first time. A computer controlled ac microcalorimeter using an optical fiber and an infrared light-emitting diode as the heat source was used down to 2 K at magnetic fields up to 8 T. The specific heat data suggest a moderate coupling in $MgCNi_3$.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 1; 363-366
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Studies on the effect of coal particle size on biodepyritization of high sulfur coal in batch bioreactor
    Autorzy:
    Singh, S.
    Srichandan, H.
    Pathak, A.
    Gahan, Ch. S.
    Lee, S.
    Kim, D. J.
    Kim, B. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/778523.pdf
    Data publikacji:
    2015
    Wydawca:
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
    Tematy:
    biodepyritization
    coal
    pyrite
    stirred tank bioreactor
    Opis:
    The moderate thermophilic mix culture bacteria were used to depyritize the Illinois coal of varying particle sizes (-100 μm, 100-200 μm, +200 μm). Mineral libration analysis showed the presence of pyrite along with other minerals in coal. Microbial depyritization of coal was carried out in stirred tank batch reactors in presence of an iron-free 9K medium. The results indicate that microbial depyritization of coal using moderate thermophiles is an efficient process. Moreover, particle size of coal is an important parameter which affects the efficiency of microbial depyritization process. At the end of the experiment, a maximum of 75% pyrite and 66% of pyritic sulphur were removed from the median particle size. The XRD analysis showed the absence of pyrite mineral in the treated coal sample. A good mass balance was also obtained with net loss of mass ranging from 5-9% showing the feasibility of the process for large scale applications.
    Źródło:
    Polish Journal of Chemical Technology; 2015, 17, 1; 97-102
    1509-8117
    1899-4741
    Pojawia się w:
    Polish Journal of Chemical Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evaluation of Surface Characteristics and Physical Properties on Biodegradable Magnesium-Calcium Alloys by Anodic Oxidation
    Autorzy:
    Kim, J.
    Lee, J.
    Yang, H.
    Park, S.
    Lim, H.
    Oh, G.
    Yun, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1191716.pdf
    Data publikacji:
    2016-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    87.85.jj
    87.85.jc
    Opis:
    The purpose of this study was to determine the effect of calcium (Ca) on the surface characteristics and physical properties of magnesium-calcium alloys after anodization. A novel binary alloy Mg-xCa (in which x=0.5, 1, or 5 wt.%) was cast by combining magnesium (99.9%) and calcium (99.9%) in an argon gas (99.99%) atmosphere. A magnesium alloy rod having a diameter of 15 mm was cut into discs, each 2 mm thick. The specimens were subjected to anodic oxidation at 120 V for 15 minutes at room temperature in an electrolyte solution consisting of calcium gluconate, sodium hexametaphosphate, and sodium hydroxide. Surface and cross-sectional morphological changes were observed using scanning electron microscopy, and the microstructures and phases were detected by means of X-ray diffraction. Hardness and surface roughness were assessed by means of a Vickers hardness tester and a surface roughness meter, respectively. The results show that the physical properties of these magnesium-calcium alloys have been improved, because it was possible to control the dissolution rate according to the amount of calcium added.
    Źródło:
    Acta Physica Polonica A; 2016, 129, 4; 736-741
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    XANES Study of La$\text{}_{0.75-x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$ Solid Solutions
    Autorzy:
    Drozd, V. A.
    Pęka̶a, M.
    Liu, R. S.
    Lee, J.-F.
    Chen, J. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2046755.pdf
    Data publikacji:
    2006-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.47.Lx
    61.10.Ht
    Opis:
    A series of solid solutions La$\text{}_{0. 75-x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$ with 0.0≤x≤0.75 was prepared via carbonate precursor precipitation method. Final sintering was performed at 1250ºC in oxygen flow atmosphere. The samples obtained were characterized by scanning electron microscope, X-ray diffraction measurements. Oxygen stoichiometry was analyzed by iodometric titration method. X-ray absorption spectroscopic methods of Mn L-edge and Mn K-edge X-ray absorption near edge structure were used to study oxidation state of manganese in the solid solutions and elucidate features of their local crystal structure. Orthorhombic crystal structure characteristics of the solid solutions were refined by Rietveld method. An increase in oxygen deficiency and average manganese oxidation state were found to accompany Gd concentration increase in La$\text{}_{0.75-x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$. These results are consistent with Mn L-edge X-ray absorption near edge structure spectra, where a gradual change of Mn oxidation state with Gd concentration increase was detected. Origins of oxygen deficiency La$\text{}_{0.75- x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$ are discussed in terms of structural disorder caused by Gd substitution for La.
    Źródło:
    Acta Physica Polonica A; 2006, 109, 4-5; 583-589
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Exchange Coupling in Magnetic Semiconductor Multilayers and Superlattices
    Autorzy:
    Furdyna, J.
    Leiner, J.
    Liu, X.
    Dobrowolska, M.
    Lee, S.
    Chung, J.
    Kirby, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1426668.pdf
    Data publikacji:
    2012-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Pp
    61.05.fj
    75.47.De
    75.70.Cn
    Opis:
    The study of ferromagnetic semiconductors continues to be of great interest because of their potential for spintronic devices. While there has been much progress in our understanding of ferromagnetic semiconductor materials - particularly of the canonical III-V system $Ga_{1-x}Mn_xAs$ - many issues still remain unresolved. One of these is the nature of interlayer exchange coupling in GaMnAs-based multilayers, an issue that is important from the point of view of possible spintronic applications. In this connection, it is important to establish under what conditions the interlayer exchange coupling between successive GaMnAs layers is antiferromagnetic or ferromagnetic, since manipulation of such interlayer exchange coupling can then be directly applied to achieve giant magnetoresistance and other devices based on this material. In this review we will describe magneto-transport, magnetization, and neutron reflectometry experiments applied to two types of GaMnAs-based multilayer structures - superlattices and tri-layers - consisting of GaMnAs layers separated by non-magnetic GaAs spacers. These measurements serve to identify conditions under which AFM coupling will occur in such GaMnAs/GaAs multilayer systems, thus providing us the information which can be used for manipulating magnetization (and thus also giant magnetoresistance) in structures based on the ferromagnetic semiconductor GaMnAs.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 5-6; 973-980
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Compositional Dependence of Hardness of Ge-Sb-Se Glass for Molded Lens Applications
    Zależność stężeniowa twardości szkła Ge-Sb-Se do zastosowań na formowane soczewki
    Autorzy:
    Park, J. K.
    Lee, J. H.
    Shin, S. Y.
    Yi, J. H.
    Lee, W. H.
    Park, B. J.
    Choi, J. H.
    Kim, N. Y.
    Choi, Y. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/352228.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    chalcogenide glasses
    Ge-Sb-Se glass
    infrared lens
    molded lens
    infrared camera
    szkło
    Ge-Sb-Se
    soczewki formowane
    twardość szkła
    kamera termowizyjna
    Opis:
    Chalcogenide glass in the ternary Ge-Sb-Se system is inherently moldable, thus being considered as a strong candidate material for use in infrared-transmitting lens applications from the viewpoint of thermal and mechanical stability. In an effort to experimentally determine compositional region suitable for the molded lens applications, we evaluate its compositional dependence of hardness. Among the constituent atoms, Ge content turns out to exert a most conspicuous correlation with hardness. This phenomenological behavior is then explained in connection with the structural evolution that Ge brings about.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1205-1208
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study On The Electro-Refining Of Tin In Acid Solution From Electronic Waste
    Badanie elektrorafinacji cyny w roztworze kwasu z e-odpadów
    Autorzy:
    Son, S. H.
    Park, S. C.
    Kim, J. H.
    Kim, Y. H.
    Lee, M. S.
    Ahn, J.-W.
    Powiązania:
    https://bibliotekanauki.pl/articles/352665.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    electrorefining
    tin
    electronic waste
    recycling
    high purity
    elektrorafinacja
    cyna
    odpady elektroniczne
    recykling
    Opis:
    The tin metal could be retractable from wasted tin scrap, sludge, and wasted electroplated solution hydrometallurgical treatment, and purification process. In order to be used as resource of electronic devices, the retracted crude metal should be purified to the extent of higher than 99.9%. In this study, tin electro-refining process was performed to purify the casted tin crude metal at various experimental conditions: at the current density of 3, 5A/dm2, and in various electrolytes such as hydrochloric acid, sulfuric acid and methansulfonic acid. Additional experiment was conducted using Rotating Disk Electrode (RDE) in order to investigate the rate determining step of tin electro-refining process. The current efficiency, 65.6%, was achievable at the condition of current density, 5A/dm2, and in the electrolyte of Hydrochloric acid. During tin electro-refining process, impurity dissolved from tin crude metal into the electrolyte was analyzed using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), and the result showed the concentration of impurity metal gradually increased. Quantitative analysis on casted tin crude metal showed that it consists of tin with 93.9 wt.% and several impurity metals of Ag, Bi, Pb, Cu, and etc. After tin electro-refining process, the purity of tin increased up to 99.985 wt.%.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1217-1220
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect Of Different Mechanical Milling Processes On Morphology And Microstructural Changes Of Nano And Micron Al-Powders
    Wpływ różnych procesów mielenia na morfologię i mikrostrukturę nanometrycznych i mikronowych proszków Al
    Autorzy:
    Kim, H.-S.
    Madavali, B.
    Eom, T.-J.
    Kim, C.- M.
    Koo, J.-M.
    Lee, T. H.
    Hong, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/355715.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Al alloys
    high-energy ball milling
    low energy ball milling
    plastic deformation
    stopy Al
    wysokoenergetyczne mielenie kulkowe
    mielenie energooszczędne
    odkształcenia plastyczne
    Opis:
    In this research, effect of the various mechanical milling process on morphology and microstructural changes of nano and micron Al-powders was studied. The milling of Al-powders was performed by both high energy and low energy ball milling process. The influence of milling (pulverizing) energy on the structural changes of Al-powders was studied. Al-nanoparticles were agglomerated during the MA and its size was increased with increasing milling while micron Al-powder gets flattened shape during high energy ball milling due to severe plastic deformation. Meanwhile, structural evolution during high energy ball milling of the nano powder occurred faster than that of the micron powder. A slight shift in the position of X-ray diffraction peaks was observed in nano Al-powders but it was un-altered in macro Al-powders. The variation in lattice parameters was observed only for nano Al powders during the high energy ball milling due to lattice distortion.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1235-1239
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Aboveground biomass and vertical distribution of crown for Taiwan red cypress 20 years after thinning
    Autorzy:
    Yen, T.-M.
    Lee, J.-S.
    Li, Ch.-L.
    Chen, Y.-T.
    Powiązania:
    https://bibliotekanauki.pl/articles/41445.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Instytut Dendrologii PAN
    Opis:
    The aim of this study was to analyze the influence of thinning on the different growth stages of the Taiwan red cypress (Chamaecyparis formosensis Matsum) on the aboveground biomass allocation patterns and vertical distribution of foliage and branch biomass at the tree level. Although numerous studies in various fields have focused on the influence of thinning effects for Taiwan red cypress, few have assessed the aboveground biomass allocation of different growth stages, or conducted a long-term thinning observation. In this study, we examined 3 even-aged plantations in central Taiwan. In 1982, 3 stands, at ages 7, 15, 21 years, simultaneously began thinning trials. A thinning study was conducted once 20 years ago, and we assessed the long-term effects. The effects of thinning in each of the stands were analyzed and compared at the tree level 20 years later. Each component of the aboveground biomass (foliage, branches, and boles) increased with the thinning intensity, regardless of the age category of the trees; however, the crown mass/ aboveground tree mass appeared the same for each tree age category, regardless of the thinning intensity. We inferred that this phenomenon might result from the same proportional increase of crown mass and aboveground tree mass as the thinning intensity was increased. An allometric function was used to quantify the vertical distribution of the foliage and branch biomass; the results showed an increase in the accumulation of the branch biomass at lower heights following thinning, and the same trend was apparent in all 3 plantations.
    Źródło:
    Dendrobiology; 2013, 70
    1641-1307
    Pojawia się w:
    Dendrobiology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Manufacturing And High Temperature Oxidation Properties Of Electro-Sprayed Fe-24.5% Cr-5%Al Powder Porous Metal
    Wytwarzanie i wysokotemperaturowe utlenianie elektro-rozpylanego porowatego proszku Fe-24.5% Cr-5%Al
    Autorzy:
    Lee, K-A.
    Oh, J-S.
    Kong, Y-M.
    Kim, B-K.
    Powiązania:
    https://bibliotekanauki.pl/articles/350912.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    powder porous metal
    electro-spray process
    electric wire explosion
    Fe-24Cr-5Al
    high temperature oxidation
    porowaty proszek metalu
    elektrorozpylanie
    utlenianie wysokotemperaturowe
    Opis:
    Fe-Cr-Al based Powder porous metals were manufactured using a new electro-spray process, and the microstructures and high-temperature oxidation properties were examined. The porous materials were obtained at different sintering temperatures (1350°C, 1400°C, 1450°C, and 1500°C and with different pore sizes (500 μm, 450 μm, and 200 μm). High-temperature oxidation experiments (TGA, Thermal Gravimetry Analysis) were conducted for 24 hours at 1000°C in a 79% N2+ 21% O2, 100 mL/min. atmosphere. The Fe-Cr-Al powder porous metals manufactured through the electro-spray process showed more-excellent oxidation resistance as sintering temperature and pore size increased. In addition, the fact that the densities and surface areas of the abovementioned powder porous metals had the largest effects on the metal’s oxidation properties could be identified.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1169-1173
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication of a Spherical Titanium Powder by Combined Combustion Synthesis and DC Plasma Treatment
    Autorzy:
    Choi, S. H.
    Ali, B.
    Hyun, S. K.
    Sim, J. J.
    Choi, W. J.
    Joo, W.
    Lim, J. H.
    Lee, Y. J.
    Kim, T. S.
    Park, K. T.
    Powiązania:
    https://bibliotekanauki.pl/articles/356067.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    combustion synthesis
    DC plasma treatment
    titanium powder
    3D printing process
    combustion parameters
    Opis:
    Combustion synthesis is capable of producing many types of refractory and ceramic materials, as well as metals, with a relatively lower cost and shorter time frame than other solid state synthetic techniques. TiO2 with Mg as reductant were dry mixed and hand compacted into a 60 mm diameter mold and then combusted under an Ar atmosphere. Depending on the reaction parameters (Mg concentration 2 ≤ α ≤ 4), the thermocouples registered temperatures between 1160°C and 1710°C . 3 mol of Mg gave the optimum results with combustion temperature (Tc) and combustion velocity (Uc) values of 1372°C and 0.26 cm/s respectively. Furthermore, this ratio also had the lowest oxygen concentration in this study (0.8 wt%). After combustion, DC plasma treatment was carried out to spheroidize the Ti powder for use in 3D printing. The characterization of the final product was performed using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and N/O analysis.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1057-1062
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Preparation Of Fine Grained SiC At Reduced Temperature By Two-Step Sintering
    Wytwarzanie drobnoziarnistego SiC w obniżonej temperaturze przez dwuetapowe spiekanie
    Autorzy:
    Kim, K.-W.
    Oh, K.-S.
    Lee, H.
    Kim, B. S.
    Chung, T.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/353772.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    SiC
    liquid phase
    two step sintering
    coarsening
    hardness
    faza ciekła
    spiekanie dwuetapowe
    odporność
    twardość
    Opis:
    Two-step sintering route was applied for the densification SiC by promoting the role of liquid phase. The specimen contained 8 vol% of liquid phase composed of Al2O3 and Y2O3. The heating schedule consisted with initial rapid heating to 2000°C and immediate quenching to 1700 or 1750°C. By heating at elevated temperature, even distribution of the liquid phase was intended. The heat treatment at reduced temperature was to suppress the evaporative loss of the liquid and to secure the time for densification. The two-step sintering effectively suppressed loss of mass and coarsening. The resultant SiC was thus dense and was composed of fine grains exhibiting hardness of 2321 kgf/mm2.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1539-1542
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A Study On The Fabrication Of Iron Powder From Forging Scale Using Hydrogen
    Próby wytwarzanie proszku żelaza metodą redukcji zgorzeliny pochodzącej z procesów kucia za pomocą wodoru
    Autorzy:
    Shin, S. M.
    Lee, D.-W.
    Yun, J.-Y.
    Kang, Ch.-Y.
    Wang, J.-P.
    Powiązania:
    https://bibliotekanauki.pl/articles/350946.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    forging scale
    hydrogen partial pressure
    hematite
    iron powder
    kucie za pomocą wodoru
    hematyt
    redukcja zgorzeliny
    proszek żelaza
    Opis:
    This study was conducted to investigate the effect of hydrogen content, temperature, reaction time for the reduction of forging scale which is mainly composed of hematite (Fe2O3). All reductive reactions were performed over the temperature range of 700 to 1200°C as well as 0.1 to 1 atm of hydrogen partial pressures. The results showed that the mechanism for the reduction of iron oxides using hydrogen gas was not a simple process, but proceeded in multiple reduction stages thermodynamically. The iron oxide was almost completely reduced to metallic iron powder with 91 wt.% of iron content in the forging scale at 0.1 atm of hydrogen partial pressure. The content of iron was however found to be increased with increasing hydrogen partial pressure from 0.1 to 1 atm with regardless of temperatures. The metallic iron powder was obtained with the mean size of 100 μm and more porous structure was observed.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1547-1549
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Self-Consolidation and Surface Modification of Mechanical Alloyed Ti-25.0 at.% Al Powder Mixture by Using an Electro-Discharge Technique
    Autorzy:
    Chang, S. Y.
    Jang, H. S.
    Yoon, Y. H.
    Kim, Y. H.
    Kim, J. Y.
    Lee, Y. K.
    Lee, W. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/354212.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    sintering
    mechanical alloying
    powder consolidation
    intermetallic compounds
    titanium aluminides
    Opis:
    Electrical discharges using a capacitance of 450 μF at 0.5, 1.0, and 1.5 kJ input energies were applied in a N2 atmosphere to obtain the mechanical alloyed Ti3Al powder without applying any external pressure. A solid bulk of nanostructured Ti3Al was obtained as short as 160 μsec by the Electrical discharge. At the same time, the surface has been modified into the form of Ti and Al nitrides due to the diffusion process of nitrogen to the surface. The input energy was found to be the most important parameter to affect the formation of a solid core and surface chemistry of the compact.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1293-1297
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Oxidation Behavior of Steel with Cr Content and Water Flow Rate
    Autorzy:
    Kim, D.-J.
    Kim, K. M.
    Shin, J. H.
    Cheong, Y. M.
    Lee, E. H.
    Lee, G. G.
    Kim, S. W.
    Kim, H. P.
    Choi, M. J.
    Lim, Y. S.
    Hwang, S. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/351548.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    steel
    flow accelerated corrosion
    Cr content
    flow rate
    surface oxides
    Opis:
    Fast water flow facilitates ferrous ion transport leading to flow accelerated corrosion (FAC) of carbon steel and the possibility of a large accident through a failure of a secondary pipe in a nuclear power plant. Ion transport is directly linked to oxide properties such as the thickness, chemical composition and porosity. This work deals with a precise observation of the cross section of the corroded specimen focusing on an oxide passivity and its thickness using SEM (scanning electron microscope) and TEM (transmission electron microscope) as well as an apparent weight loss and a surface observation for the specimens corroded using a rotating cylindrical electrode autoclave system in pure water of pH 7 at 150°C having dissolved oxygen below 1 ppb within a flow rate range of 0 to 10 m/s. The Cr content in steel was changed from 0.02 to 2.4 wt%. Increasing the Cr content in the alloy, the FAC rate and oxide thickness decreased. The oxide porosity tends to decrease with the Cr content and immersion time owing to the development of Cr containing oxide. The oxidation behavior is not changed with the immersion time.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1383-1387
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Spontaneous Formation of Titanium Nitride on the Surface of a Ti Rod Induced by Electro-Discharge-Heat-Treatment in an N2 Atmosphere
    Autorzy:
    Lee, W. H.
    Yoon, Y. H.
    Kim, Y. H.
    Lee, Y. K.
    Kim, J. Y.
    Chang, S. Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/352477.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    titanium
    surface modification
    diffusion
    heat treatment
    XPS
    Opis:
    A single pulse of 2.0 to 3.5 kJ of input energy from a 450 mF capacitor was applied to a commercially pure Ti rod in a N2 atmosphere. The surface of the Ti rod transformed from TiO2 into titanium nitride in times as short as 159 msec, providing a bimodal morphology of the cross-section. A much higher value of hardness that was observed at the edge of the cross-section was attributed to nitrogen-induced solid-solution hardening that occurred during the electrical discharge process. The activation energy (Ea) for the diffusion process was estimated to be approximately 86.9 kJ/mol. Results show that the electrical discharge process is a possible potential method for the nitriding of Ti; advantages include a short processing time and control of the nitrided layer without dimensional changes.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1281-1285
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Low-velocity impact characteristics of composite plates with shape memory alloy wires
    Niskoprędkościowe charakterystyki uderzeniowe płyt kompozytowych zawierających włókna ze stopów z pamięcią kształtu
    Autorzy:
    Rim, M.-S.
    Kim, E.-H.
    Lee, I.
    Choi, I.-H.
    Ahn, S.-M.
    Koo, K.-N.
    Bae, J.-S.
    Roh, J.-H.
    Powiązania:
    https://bibliotekanauki.pl/articles/279293.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    shape memory alloy
    SMAHC
    composite
    low-velocity impact
    impact resistance
    Opis:
    To investigate impact characteristics of shape memory alloy hybrid com- posites (SMAHC), several experiments were performed. Tensile tests of shape memory alloy (SMA) wires were carried out to investigate thermomechanical properties, and low-velocity impact tests of SMAHC plates and conventional composite plates without SMAs at the critical energy level. low-velocity impact tests of several types of composite plates, including composite plates with embedded SMAs/Fe/Al wires and conventional composite plates, were also done. Results of these experiments show that embedding SMAs in a composite plate can improve the impact resistance. Lastly, low-velocity impact tests of SMAHC plates with SMA wires embedded at different positions through the thickness were performed in an effort to improve the impact resistance. Embedding SMA wires at a lower position in the composite plates was the most effective for improving the impact resistance.
    Do analizy charakterystyk uderzeniowych hybrydowych kompozytów SMAHC zwierających włókna SMA ze stopów wykazujących efekt pamięci kształtu przeprowadzono szereg badań eksperymentalnych. Przeprowadzono próby na rozciąganie włókien SMA w celu zbadania ich właściwości termomechanicznych oraz niskoprędkościowe testy uderzeniowe płyt SMAHC oraz konwencjonalnych płyt laminowanych przy energii krytycznej. Wykonano także testy dla płyt kompozytowych zawierających włókna SMA/Fe/Al. Rezultaty doświadczeń pokazały, że wbudowanie w strukturę laminatu włókien SMA może zwiększyć odporność kompozytu na obciążenie uderzeniowe. Opisano również badania eksperymentalne płyt SMAHC z włóknami SMA wbudowanymi na różnej głębokości. Wykazano, że najlepsze parametry posiadają kompozyty z włóknami umieszczonymi możliwie daleko od uderzanej powierzchni.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2011, 49, 3; 841-857
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Oxide Formation In Metal Injection Molding Of 316L Stainless Steel
    Tworzenie tlenków podczas wtryskiwania proszku stali nierdzewnej 316L
    Autorzy:
    Jang, J. M.
    Lee, W.
    Ko, S.-H.
    Han, C.
    Choi, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/351352.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    powder injection molding
    sintering
    316L stainless steel
    sintering atmosphere
    micro parts
    wtryskiwanie proszku
    spiekanie
    stal nierdzewna 316L
    mikro-część
    Opis:
    The effects of sintering condition and powder size on the microstructure of MIMed parts were investigated using water-atomized 316L stainless steel powder. The 316L stainless steel feedstock was injected into micro mold with micro features of various shapes and dimensions. The green parts were debound and pre-sintered at 800°C in hydrogen atmosphere and then sintered at 1300°C and 1350°C in argon atmosphere of 5torr and 760torr, respectively. The oxide particles were formed and distributed homogeneously inside the sample except for the outermost region regardless of sintering condition and powder size. The width of layer without oxide particles are increased with decrease of sintering atmosphere pressure and powder size. The fine oxides act as the obstacle on grain growth and the high sintering temperature causes severe grain growth in micro features due to larger amount of heat gain than that in macro ones.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1281-1285
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Thermal Conductivity and Microstructure of Copper Coated Graphite Composite by Spark Plasma Sintering Process
    Autorzy:
    Park, S. H.
    Kim, D. B.
    Lee, R. G.
    Son, I. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/355632.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    metal matrix composites
    thermal conductivity
    thermal expansion
    interfacial bonding
    spark plasma sintering
    Opis:
    This study focuses on the fabrication of thermal management material for power electronics applications using graphite flake reinforced copper composites. The manufacturing route involved electroless plating of copper in the graphite flake and sintering process are optimized. The microstructures, interface, thermal properties, and relative density of graphite/Cu composites are investigated. The relative density of the composites shows 99.5% after sintering. Thermal conductivities and coefficients of thermal expansion of this composites were 400-480 Wm-1K-1 and 8 to 5 ppm k-1, respectively. Obtained graphite nanoplatelets-reinforced composites exhibit excellent thermo-physical properties to meet the heat dispersion and matching requirements of power electronic devices to the packaging materials.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1303-1306
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Trace Elements (Co, Cr) on the Microstructure and Physical Properties of Al-Si-Cu-Mg-Fe Extruded Alloy
    Autorzy:
    Ahn, S. S.
    Sharief, P.
    Lee, C. H.
    Son, H. T.
    Kim, Y. H.
    Kim, Y. C.
    Hong, S.
    Hong, S. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/352787.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Al-Si alloy
    microstructure
    extrusion
    coefficient of thermal expansion
    trace elements
    Opis:
    Trace elements Co, Cr were added to investigate their influence on the microstructure and physical properties of Al-Si extruded alloy. The Co, Cr elements were randomly distributed in the matrix, forms intermetallic phase and their existence wereconfirmed by XRD, EDS and SEM analysis. With addition of trace elements, the microstructure was modified, Si particle size was reduced and the growth rate of β-(Al5 FeSi) phase limited. Compared to parent alloy, hardness and tensile strength were enhanced while the linear coefficient of thermal expansion (CTE) was significantly reduced by 42.4% and 16.05% with Co and Cr addition respectively. It is considered that the low CTE occurs with addition of Co was due to the formation of intermetallic compound having low coefficient of thermal expansion. The results suggested that Co acts as an effective element in improving the mechanical properties of Al-Si alloy.
    Źródło:
    Archives of Metallurgy and Materials; 2019, 64, 3; 857-862
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Carbon Co-Deposition During Gas Reduction of Water-Atomized Fe-Cr-Mo Powder
    Autorzy:
    Ali, B.
    Choi, S. H.
    Seo, S. J.
    Maeng, D. Y.
    Lee, C. G.
    Kim, T. S.
    Park, K. T.
    Powiązania:
    https://bibliotekanauki.pl/articles/352709.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    water atomization
    Fe-based powder
    oxide reduction
    powder metallurgy
    sinter-hardening alloys
    Opis:
    The water atomization of iron powder with a composition of Fe-3Cr-0.5Mo (wt.%) at 1600°C and 150 bar creates an oxide layer, which in this study was reduced using a mixture of methane (CH4) and argon (Ar) gas. The lowest oxygen content was achieved with a 100 cc/min flow rate of CH4, but this also resulted in a co-deposition of carbon due to the cracking of CH4. This carbon can be used directly to create high-quality, sinter hardenable steel, thereby eliminating the need for an additional mixing step prior to sintering. An exponential relationship was found to exist between the CH4 gas flow rate and carbon content of the powder, meaning that its composition can be easily controlled to suit a variety of different applications.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1119-1124
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An analysis on the thermal characteristics according to the viscosity of bearing lubricant and the cooling condition for the high speed motor spindle
    Autorzy:
    Choi, D. B.
    Lee, J. J.
    Kim, S. T.
    Kwon, H. D.
    Kim, C. Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/1429194.pdf
    Data publikacji:
    2008
    Wydawca:
    Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
    Tematy:
    high speed motor spindle
    thermal displacement cooling condition
    lubricant viscosity
    Opis:
    Thermal displacement of the high speed machine tools has a large influence on machining accuracy. The high speed motor spindle with many heat sources is widely used for the high speed machine tools recently. The important problem in this spindle is to reduce and minimize the thermal effects by motor and bearings. This paper presents the analysis on thermal characteristics for high speed motor spindle system with oil-air lubricated angular contact ceramic ball bearings and built-in motor. An analysis on the thermal characteristics of spindle is performed according to the cooling conditions and the viscosity of bearing lubricants by using finite element method. This results can be applied to the design and manufacturing for the high speed motor spindle.
    Źródło:
    Journal of Machine Engineering; 2008, 8, 4; 88-98
    1895-7595
    2391-8071
    Pojawia się w:
    Journal of Machine Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Surface Modification of Self-Consolidated Microporous Ti Implant Compacts Fabricated by Electro-Discharge-Sintering in Air
    Autorzy:
    Jo, Y. J.
    Yoon, Y. H.
    Kim, Y. H.
    Chang, S. Y.
    Kim, J. Y.
    Lee, Y. K.
    Van Tyne, C. J.
    Lee, W. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/356790.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    titanium
    implant
    porous
    sintering
    X-ray photoelectron spectroscopy (XPS)
    Opis:
    A single pulse of 0.75-2.0 kJ/0.7g of atomized spherical Ti powders from 300 mF capacitor was applied to produce a microporous Ti implant compact by electro-discharge-sintering (EDS). A solid core in the middle of the compact surrounded by a microporous layer was found. X-ray photoelectron spectroscopy was employed to study the surface characteristics of the EDS Ti compact and it revealed that Ti, C and O were the main constituents on the surface with a smaller amount of N. The surface was lightly oxidized and was primarily in the form of TiO2 resulting from the air oxidation during EDS processing. The lightly oxidized surface of the EDS compact also exhibited Ti nitrides such as TiN and TiON, which revealed that the reaction between air constituents and the Ti powders even in times as short as 128 msec.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1287-1291
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect Of The Desorption-Recombination Temperature On The Microstructure And Magnetic Properties Of HDDR Processed Nd-Fe-B Powders
    Wpływ temperatury desorpcji-rekombinacji na mikrostrukturę i właściwości magnetyczne proszków Nd-Fe-B przetwarzanych metodą HDDR
    Autorzy:
    Lee, J.-G.
    Cha, H.-R.
    Liu, S.
    Yu, J.-H.
    Baek, Y.-K.
    Kwon, H.-W.
    Powiązania:
    https://bibliotekanauki.pl/articles/353723.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Nd-Fe-B
    HDDR
    permanent magnet
    grain boundary
    metoda HDDR
    magnes trwały
    granica ziarna
    Opis:
    The effect of the desorption-recombination temperature on the microstructure and magnetic properties of hydrogenation-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders was studied. The NdxB6.4Ga0.3Nb20.2Febal (x=12.5-13.5, at.%) casting alloys were pulverized after homogenizing annealing, and then subjected to HDDR treatment. During the HDDR process, desorption-recombination (DR) reaction was induced at two different temperature, 810°C and 820°C. The higher Nd content resulted in enhanced coercivity of the HDDR powder, and which was attributed to the thicker and more uniform Nd-rich phase along grain boundaries. But this uniform Nd-rich phase induced faster grain growth. The remanence of the powder DR-treated at 820°C is higher than that DR-treated at 810°C. In addition, it was also confirmed that higher DR temperature is much more effective to improve squareness.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1499-1501
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Reaction Kinetics and Morphological Study of TiNb2O7 Synthesized by Solid-State Reaction
    Autorzy:
    Choi, S. H.
    Ali, B.
    Choi, K. S.
    Hyun, S. K.
    Sim, J. J.
    Choi, W. J.
    Joo, W.
    Lim, J. H.
    Lee, T. H.
    Kim, T. S.
    Park, K. T.
    Powiązania:
    https://bibliotekanauki.pl/articles/355326.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    solid state reaction
    kinetic analysis
    quantitative phase analysis
    TiNb2O7 synthesis
    Opis:
    Although TiNb2O7 is regarded as a material with high application potential in lithium-ion batteries (LIBs) and solid-oxide fuel cells (SOFCs), it has been difficult to find suitable cost-effective conditions for synthesizing it on a commercial scale. In this study, TiNb2O7 compounds were synthesized by a solid state synthesis process. For stoichiometrically precise synthesis of the TiNb2O7 phase, the starting materials, TiO2 and Nb2O5 were taken in a 1:1 molar ratio. Activation energy and reaction kinetics of the system were investigated at various synthesis temperatures (800,1000,1200, and 1400°C) and for various holding durations (1,5,10, and 20 h). Furthermore, change in the product morphology and particle size distribution were also evaluated as a function of synthesis temperature and duration. Additionally, quantitative phase analysis was conducted using the Rietveld refinement method. It was found that increases in the synthesis temperature and holding time lead to increase in the mean particle size from 1 to 4.5 μm. The reaction rate constant for the synthesis reaction was also calculated.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1051-1056
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Formation of Tungsten/Ammonium Perchlorate Composites and Their Reaction Kinetics
    Autorzy:
    Shim, H.-M.
    Lee, E.-A.
    Kim, J.-K.
    Kim, H.-S.
    Koo, K.-K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358373.pdf
    Data publikacji:
    2015
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    ammonium perchlorate
    composite
    thermal decomposition
    Opis:
    The reaction kinetics of tungsten nanoparticles/ammonium perchlorate (W/AP) composites, produced by a spray drying technique, were analyzed and compared with those of neat AP particles and aluminum nanoparticles/AP (Al/AP) composites. The W was found to raise the onset temperature of the thermal decomposition of AP by increasing the activation energy, whereas Al conversely lowered the onset temperature of AP due to the decreased activation energy. From the master plots of kinetic models with the experimental data, the Prout-Tompkins model and the 1-D diffusion controlled model were found to describe the low-temperature decomposition (LTD) and high-temperature decomposition (HTD), respectively, giving remarkable agreement with experimental curves for all heating rates. The presence of W was found to increase the HTD zone width compared with that of neat AP particles and Al/AP composites. Analysis of the average activation energy and pre-exponential factor showed that W increases the energy barrier and the frequency of occurrence of the reaction compared with that of neat AP particles at the LTD state, whereas W decreases both of them at the HTD state. The effect of Al was also shown to be similar to that of W, but the magnitudes of the variation in activation energy and the pre-exponential factor were relatively small.
    Źródło:
    Central European Journal of Energetic Materials; 2015, 12, 4; 703-722
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Self-Consolidation Mechanism of Ti5Si3 Compact Obtained by Electro-Discharge-Sintering Directly from Physically Blended Ti-37.5 At.% Si Powder Mixture
    Autorzy:
    Chang, S. Y.
    Cheon, Y. W.
    Yoon, Y. H.
    Kim, Y. H.
    Kim, J. Y.
    Lee, Y. K.
    Lee, W. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/353022.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    sintering
    mechanical alloying
    powder consolidation
    intermetallic compounds
    titanium silicide
    Opis:
    Characteristics of electro-discharge-sintering of the Ti-37.5at.% Si powder mixture was investigated as a function of the input energy, capacitance, and discharge time without applying any external pressure. A solid bulk of Ti5Si3 was obtained only after in less than 129 μsec by the EDS process. During a discharge, the heat is generated to liquefy and alloy the particles, and which enhances the pinch pressure can condensate them without allowing a formation of pores. Three step processes for the self-consolidation mechanism during EDS are proposed; (a) a physical breakdown of oxide film on elemental as-received powder particles, (b) alloying and densifying the consolidation of powder particles by the pinch pressure, and (c) diffusion of impurities into the consolidated surface.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1299-1302
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Tunneling Magnetoresistance in Ferromagnetic Junctions: Bias Dependence
    Autorzy:
    Barnaś, J.
    Lee, S. F.
    Holody, P.
    Schelp, L. F.
    Petroff, F.
    Fert, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1968769.pdf
    Data publikacji:
    1998-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.40.Gk
    73.40.Rw
    75.70.-i
    Opis:
    Electron tunneling between two ferromagnetic electrodes across an insulating barrier is analysed theoretically and experimentally. The barrier is either uniform or it includes a layer of small magnetic metallic particles. Particular attention is paid to the origin of the tunneling magnetoresistance and its bias dependence, as well as to the effects due to Coulomb blockade.
    Źródło:
    Acta Physica Polonica A; 1998, 93, 2; 387-391
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Oligonol prevented the relapse of dextran sulfate sodium-ulcerative colitis through enhancing Nrf2-mediated antioxidative defense mechanism
    Autorzy:
    Kim, K.-J.
    Park, J.-M.
    Lee, J.-S.
    Kim, Y.S.
    Kangwan, N.
    Han, Y.-M.
    Kang, E.A.
    An, J.M.
    Park, Y.K.
    Hahm, K.-B.
    Powiązania:
    https://bibliotekanauki.pl/articles/69501.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Fizjologiczne
    Tematy:
    ulcerative colitis
    inflammatory bowel disease
    oxidative stress
    oligonol
    polyphenol
    adaptive response
    quinone oxidoreductase
    relapse
    nuclear factor-kappaB
    tumour necrosis factor-alpha
    Źródło:
    Journal of Physiology and Pharmacology; 2018, 69, 3
    0867-5910
    Pojawia się w:
    Journal of Physiology and Pharmacology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    ZnO Nanorods on Nanofibrous ZnO Seed Layers by Hydrothermal Method and Their Annealing Effects
    Autorzy:
    Yim, K.
    Jeon, S.
    Kim, M.
    Kim, S.
    Nam, G.
    Lee, D.
    Kim, Jin
    Kim, Jong
    Leem, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1491348.pdf
    Data publikacji:
    2012-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.Dz
    81.15.Lm
    78.55.Et
    Opis:
    ZnO nanorods were grown by using the hydrothermal method on p-type Si (100) substrates with nanofibrous ZnO seed layers. Before the ZnO nanorods growth, nanofibrous ZnO seed layers were spin-coated onto the Si substrates. The structural and optical properties of ZnO nanorods were characterized by scanning electron microscopy, X-ray diffraction, and photoluminescence. The fibrous ZnO nanorods is possible due to the surface morphology of the nanofibrous ZnO seed layers. To investigate annealing effects of the ZnO nanorods, the post-annealing process was carried out at various temperatures ranging from 300 to 700C under argon conditions. The structural and optical properties of the ZnO nanorods were also affected by the post-annealing treatment.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 1; 214-216
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optical Properties of Multi-Stacked InAs Quantum Dots Embedded in GaAs/InGaAs Strained Layer and its Annealing Behaviors
    Autorzy:
    Kim, D.
    Kim, G.
    Jeon, S.
    Cho, M.
    Choi, H.
    Kim, M.
    Lee, D.
    Kim, J.
    Eom, G.
    Leem, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1537752.pdf
    Data publikacji:
    2010-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    78.67.Hc
    78.55.Cr
    81.05.Ea
    Opis:
    Multi-stacked InAs QDs embedded in ten periods of GaAs/$In_{0.1}Ga_{0.9}As$ strained layers were grown by MBE and their optical properties were investigated by using PL spectroscopy. For the QDs embedded in ten periods of GaAs/$In_{0.1}Ga_{0.9}As$ strained layers, the PL intensity is enhanced about 4.7 times and a narrower FWHM of 26 meV is observed compared to those of the conventional multi-stacked QDs. The PL spectra of the InAs QDs show blue-shifts of about 50 meV with increasing annealing temperature up to 850°C. At annealing temperature of 600°C, the FWHM of the PL peak is reduced to 16 meV and PL intensity is enhanced compared to those of the as-grown sample, which indicates improvement of size uniformity and crystal quality of the QDs.
    Źródło:
    Acta Physica Polonica A; 2010, 117, 6; 941-944
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Efficient online handwritten Chinese character recognition system using a two-dimensional functional relationship model
    Autorzy:
    Chang, Y. F.
    Lee, J. C.
    Mohd Rijal, O.
    Syed Abu Bakar, S. A. R.
    Powiązania:
    https://bibliotekanauki.pl/articles/908140.pdf
    Data publikacji:
    2010
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    2D
    współczynnik determinacji
    rozpoznawanie
    pismo odręczne
    pismo chińskie
    falka Haara
    model relacyjny
    2D functional classifier
    coefficient of determination
    handwritten Chinese character recognition
    Haar wavelet
    multidimensional functional relationship model
    Opis:
    This paper presents novel feature extraction and classification methods for online handwritten Chinese character recognition (HCCR). The X-graph and Y-graph transformation is proposed for deriving a feature, which shows useful properties such as invariance to different writing styles. Central to the proposed method is the idea of capturing the geometrical and topological information from the trajectory of the handwritten character using the X-graph and the Y-graph. For feature size reduction, the Haar wavelet transformation was applied on the graphs. For classification, the coefficient of determination [...] from the two-dimensional unreplicated linear functional relationship model is proposed as a similarity measure. The proposed methods show strong discrimination power when handling problems related to size, position and slant variation, stroke shape deformation, close resemblance of characters, and non-normalization. The proposed recognition system is applied to a database with 3000 frequently used Chinese characters, yielding a high recognition rate of 97.4% with reduced processing time of 75.31%, 73.05%, 58.27% and 40.69% when compared with recognition systems using the city block distance with deviation (CBDD), the minimum distance (MD), the compound Mahalanobis function (CMF) and the modified quadratic discriminant function (MQDF), respectively. High precision rates were also achieved.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2010, 20, 4; 727-738
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Heat Treatment on Microstructure and Impact Toughness of Ti-6Al-4V Manufactured by Selective Laser Melting Process
    Autorzy:
    Lee, K.-A.
    Kim, Y.-K.
    Yu, J.-H.
    Park, S.-H.
    Kim, M.-C.
    Powiązania:
    https://bibliotekanauki.pl/articles/354570.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    selective laser melting
    Ti-6Al-4V
    microstructure
    impact toughness
    heat treatment
    Opis:
    This study manufactured Ti-6Al-4V alloy using one of the powder bed fusion 3D-printing processes, selective laser melting, and investigated the effect of heat treatment (650°C/3hrs) on microstructure and impact toughness of the material. Initial microstructural observation identified prior-β grain along the building direction before and after heat treatment. In addition, the material formed a fully martensite structure before heat treatment, and after heat treatment, α and β phase were formed simultaneously. Charpy impact tests were conducted. The average impact energy measured as 6.0 J before heat treatment, and after heat treatment, the average impact energy increased by approximately 20% to 7.3 J. Fracture surface observation after the impact test showed that both alloys had brittle characteristics on macro levels, but showed ductile fracture characteristics and dimples at micro levels.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1341-1346
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Growth and Characterization of Indium-Doped Zinc Oxide Thin Films Prepared by Sol-Gel Method
    Autorzy:
    Kim, M.
    Yim, K.
    Kim, S.
    Nam, G.
    Lee, D.
    Kim, Jin
    Kim, Jong
    Leem, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1491351.pdf
    Data publikacji:
    2012-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.Dz
    81.20.Fw
    78.66.Hf
    Opis:
    Indium-doped ZnO thin films were deposited by sol-gel spin-coating method with various In content. The effects of In content on the structural and optical properties of the indium-doped ZnO thin films were investigated by scanning electron microscopy, X-ray diffraction, and UV-visible spectroscopy. The particle-like surface morphology and the crystallinity of the indium-doped ZnO thin films were affected by change in the In content, especially at the In content of 3 at.%. The values of direct band gap were decreased with increase in the In content. The width of localized states in the optical band gap of the indium-doped ZnO thin films were changed with In content and the Urbach energy $(E_{U})$ was changed inversely with optical band gap of the indium-doped ZnO thin films.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 1; 217-220
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Quantitative Analysis of Cryomilled Nanocrystalline Ti-6Al-4V Alloy Powder by X-Ray Diffraction
    Autorzy:
    Oh, M.
    Yu, H. K.
    Lee, J.-H.
    Oh, M. C.
    Jung, S.-H.
    Ahn, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/356265.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    nanocrystalline
    cryomilling
    Ti alloy
    X-ray diffraction
    size-strain plot method
    Opis:
    A nanocrystalline Ti alloy powder was fabricated using cryomilling. The grain size and lattice strain evolution during cryomilling were quantitatively analyzed using X-ray diffraction (XRD) based on the Scherrer equation, Williamson-Hall (W-H) plotting method, and size-strain (S-S) method assuming uniform deformation. Other physical parameters including stress and strain have been calculated. The average crystallite size and the lattice strain evaluated from XRD analysis are in good agreement with the result of transmission electron microscopy (TEM).
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1439-1442
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Self-Consolidation Mechanism Of Porous Ti-6Al-4V Implant Prototypes Produced By Electro-Discharge-Sintering Of Spherical Ti-6Al-4V Powders
    Mechanizm autokonsolidacji prototypów porowatych implantów wytworzonych przez spiekanie sferycznych proszków Ti-6Al-4V
    Autorzy:
    Lee, W. H.
    Jo, Y. J.
    Kim, Y. H.
    Jo, Y. H.
    Seong, J. G.
    Van Tyne, C. J.
    Chang, S. Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/356277.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Ti-6Al-4V
    implant
    porous
    sintering
    electrodischarge
    porowatość
    spiekanie
    proszki spiekane
    Opis:
    Electro-Discharge-Sintering (EDS) was employed to fabricate Ti-6Al-4V porous implant prototypes from atomized powders (100 – 150 μm), that were subjected to discharges of 0.75 to 2.0 kJ/0.7g-powder from 150, 300, and 450 μF capacitors. Both fully porous and porous-surfaced Ti-6Al-4V compacts with various solid core sizes were self-consolidated in less than 86 – 155 μsec. It is known that EDS can simultaneously produce the pinch pressure to squeeze and deform powder particles and the heat to weld them together. The formation of a solid core in these prototypes depends on the amounts of both the pinch pressure and heat generated during a discharge. The size of the solid core and the thickness of the porous layer can be successfully controlled by manipulating the discharge conditions such as input energy and capacitance.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1185-1189
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Argon Plasma in a New Process for Improving the Physical and Anti-bacterial Properties of Crosslinked Cotton Cellulose with Dimethyloldihydroxyethyleneurea-Maleic Acid
    Zastosowanie plazmy niskotemperaturowej w środowisku argonu w procesie obróbki tkanin bawełnianych sieciowanych za pomocą kwasu dimetylodihydroxyetylenourylomaleinowego dla polepszenia właściwosci fizycznych oraz antybakteryjnych
    Autorzy:
    Tsou, C H
    Suen, M C
    Tsou, C Y
    Chen, J C
    Yeh, J T
    Lin, S M
    Lai, Y C
    Hwang, J Z
    Huang, S H
    Hung, W S
    Hu, C C
    Lee, K R
    Lai, J Y
    Powiązania:
    https://bibliotekanauki.pl/articles/232331.pdf
    Data publikacji:
    2015
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
    Tematy:
    cotton
    plasma
    antibacterial
    crosslinking
    crosslink length
    crosslinks number per anhydroglucose
    surface distribution
    odour absorption
    bawełna
    plazma
    właściwości antybakteryjne
    sieciowanie tkanin bawełnianych
    kwas dimetylodihydroxyetylenourylomaleinowy
    odporności na zagniecenia
    pochłanianie zapachów
    żywica termoutwardzalna
    Opis:
    This study reports the findings of an argon (Ar) plasma treatment added to the traditional pad-dry-cure process between dry and cure treatments. This new process is called the "paddry-plasma-cure process". The crosslinking agent was a mixture of dimethyloldihydroxyethyleneurea (DMDHEU) and maleic acid (MA). Results show that Ar plasma treatment can increase the bonded crosslinking agent (i.e., the nitrogen content). The dry crease recovery angle (DCRA), wet crease recovery angle (WCRA), and tensile strength retention (TSR) of the pad-dry-plasma-cure finished fabrics were higher than those of traditional pad-dry-cure finished fabrics at a given nitrogen content. Additionally it was found that the number of crosslinks per anhydroglucose unit (CL/AGU) and the length of crosslinks of pad-dry-plasma-cure-finished fabrics were higher than that of traditional pad-dry-cure finished fabrics at the same resin concentration in the pad bath. DCRA, WCRA and TSR values of pad-dry-plasma-cure-finished fabrics were higher than those of pad-dry-curefinished fabrics at the same CL/AGU value. However, activation energies for the pad-dryplasma-cure process were higher than those for the pad-dry-cure process. The anti-bacterial ability and odour absorption of the pad-dry-plasma-cure and pad-dry-plasma-cure finished fabrics were higher than those for the pad-dry-cure finished fabrics. The surface distribution of crosslinking agents for the pad-dry-plasma-cure process was higher than that of the pad-dry-cure process. Thus the pad-dry-plasma-cure process is excellent for improving the physical properties, bacterial inhibition, and odour absorption of finished cotton fabrics and for decreasing their formaldehyde release.
    Artykułu odnosi się do problematyki możliwości i celowości wprowadzenia modyfikacji plazmowej w warunkach niskociśnieniowych i w środowisku argonu do konwencjonalnego procesu wykończenia przeciw mnącego z zastosowaniem reaktywnych żywic termoutwardzalnych. Badano kąt odprężenia na sucho i na mokro, i stwierdzono polepszenie właściwości odporności na zagniecenia w wyniku dodatkowego zastosowania plazmy. Badano również właściwości antybakteryjne i pochłanianie zapachów, które okazały się korzystniejsze dla dodatkowej obróbki plazmowej. W wyniku zmodyfikowanej obróbki uzyskano mniejsze wydzielanie formaldehydu z gotowej tkaniny.
    Źródło:
    Fibres & Textiles in Eastern Europe; 2015, 1 (109); 49-56
    1230-3666
    2300-7354
    Pojawia się w:
    Fibres & Textiles in Eastern Europe
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication and Characterization of GaN/Polymer Composite p-n Junction with PEDOT Nanoparticle Interface Layer
    Autorzy:
    Kim, M.
    Jin, S.
    Choi, H.
    Kim, G.
    Yim, K.
    Kim, S.
    Nam, G.
    Yoon, H.
    Kim, Y.
    Lee, D.
    Kim, Jin
    Kim, Jong
    Leem, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505152.pdf
    Data publikacji:
    2011-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.61.Ey
    81.15.Gh
    Opis:
    A heavily Si-doped GaN/polymer hybrid structure with p-type poly(3,4-ethylene-dioxythiophene):beta-1,3-glucan (PEDOT nanoparticle) interface layer has been fabricated. The Si-doped GaN thin film with carrier concentration of 1 × $10^{19} cm^{-3}$ was grown by metal-organic chemical vapor deposition. The PEDOT nanoparticle with various sizes ranging from 60 to 120 nm was synthesized via a miniemulsion polymerization process. The electrical conductivity of the PEDOT nanoparticle is less than 1.2 S/cm. The current-voltage (I-V) characteristic of the hybrid structure shows diode-like behavior. The I-V characteristic was examined in the framework of the thermionic emission model. The ideality factor of the structure without PEDOT nanoparticle interface layer is 12.9. However, the ideality factor of the hybrid structure with PEDOT nanoparticle interface layer is obtained as 1.9. The value of ideality factor is dramatically decreased by inserting the PEDOT nanoparticle interface layer.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 6; 875-879
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Warm Tensile Deformation Behavior and Constitutive Equation of Supersaturated Solid-Solutionized Al-9Mg Extruded Alloy
    Autorzy:
    Yang, Seung Y.
    Kim, Bong H.
    Lee, Da B.
    Choi, Kweon H.
    Kim, Nam S.
    Ha, Seong H.
    Yoon, Young O.
    Lim, Hyun K.
    Kim, Shae
    Kim, Young J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2048882.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    aluminum alloy
    Al-9Mg alloy
    tensile test
    constitutive equation
    Opis:
    In this paper, as a purpose to apply the supersaturated solid-solutionized Al-9Mg alloy to the structural sheet parts of automotive, tensile tests were conducted under the various conditions and a constitutive equation was derived from the tensile test results. Al-9Mg alloy was produced using a special Mg master alloy containing Al2Ca during the casting process and extruded into the sheet. In order to study the deformation behavior of Al-9Mg alloy in warm temperature forming environments, tensile tests were conducted under the temperature of 373 K-573 K and the strain rate of 0.001/s~0.1/s. in addition, by using the raw data obtained from tensile tests, a constitutive equation of the Al-9Mg alloy was derived for predicting the optimized condition of the hot stamping process. Al-9Mg alloy showed uncommon deformation behavior at the 373 K and 473 K temperature conditions. The calculated curves from the constitutive equation well-matched with the measured curves from the experiments particularly under the low temperature and high strain rate conditions.
    Źródło:
    Archives of Metallurgy and Materials; 2021, 66, 4; 1013-1018
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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