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11.
Isamu Ogura Naomi Hashimoto Mari Kotake Hiromu Sakurai Atsuo Kishimoto Kazumasa Honda 《Aerosol science and technology》2014,48(7):758-767
A simple sampling method to collect aerosol particles for transmission electron microscope (TEM) analysis was developed by R’mili and others in 2013. The method involves passing air through a holey carbon film-coated copper mesh TEM grid (holey carbon grid) and sampling particles by filtration. In this study, we proposed a modified calculation method to represent the collection efficiencies of holey carbon grids, taking into consideration the porosity of the copper mesh. We then evaluated the particle collection efficiencies of holey carbon grids both theoretically and experimentally. We tested the collection efficiency of two types of holey carbon grids, with nominal pore sizes of 1.2 and 0.6 μm, using particles of monodispersed polystyrene latex (PSL) and potassium chloride. The overall collection efficiency of each grid (Egrid) was determined by the downstream/upstream concentration ratio measured by condensation particle counters (CPCs). In addition, for PSL particles, the collection efficiency of the holey carbon film (Efilm) was determined by the ratio of the number of particles on the film (counted on a scanning electron microscope) to the number of inflow particles (counted by a CPC). We compared model calculations against the experimental results obtained in this study and those reported by R’mili and others in 2013. These data showed that the calculated Egrid values were in reasonably good agreement with the experimental Egrid values. However, although the model calculation indicated that Efilm ≈ Egrid, there was an inconsistency between the experimental Efilm and Egrid, which requires further investigation in order to determine its cause.
Copyright 2014 American Association for Aerosol Research 相似文献
12.
Grimshaw Andrew Morgan Mark Merrill Duane Kishimoto Hiro Savva Andreas Snelling David Smith Chris Berry Dave 《Computer》2009,42(2):27-34
To expand the use of distributed computer infrastructures as well as facilitate grid interoperability, OGSA has developed standards and specifications that address a range of scenarios, including high-throughput computing, federated data management, and service mobility. 相似文献
13.
Teruhisa Horita Haruo Kishimoto Katsuhiko Yamaji Manuel E. Brito Yueping Xiong Harumi Yokokawa 《Journal of power sources》2009,193(1):180-184
Reactivity of oxide scale on Fe-Cr alloy with Na-containing gases was examined to estimate the stability against sodium (Na): vapors of NaCl and Na2SO4 exposures with air flow at 1073 K. The identified reaction phases were Cr-Mn spinel, Cr2O3, and alloy from the X-ray diffraction of surface with no Na-reaction products. However, the protective oxide scales (Mn-Cr spinel and Cr2O3 layers) on the Fe-Cr alloy were partially decomposed by reacting with Na to form Na-compounds inside the oxide scale/alloy interfaces. In some parts, anomalous oxide scales were found around the oxide scale/Fe-Cr alloy interfaces, with forming Na-rich compounds: the compounds were distributed inner parts of oxide scales around oxide scale/alloy interfaces. The stability of oxide scales and degradation were discussed based on the observed distribution of elements. 相似文献
14.
The fluoride adsorption onto the hydroxide flocs of Al(III), Fe(III), or a mixture of the two was studied. The optimum pH was influenced by the flocs’ solubility and surface charge. Although the Al(III) hydroxide flocs had a maximum adsorption capacity at the equilibrium concentration of 8 mg-F/L, the two-stage adsorption process revealed that the mixture of the Al(III) and Fe(III) hydroxide flocs required the smallest adsorbent dose as the concentration changed from 40 to 8 mg-F/L. Thus, the simultaneous dosing of Al(III) and Fe(III) combined with a two-stage adsorption process appears to be an effective option for fluoride removal. 相似文献
15.
Noriya Izu Haruo Kishimoto Takahisa Omata Kousuke One 《Science and Technology of Advanced Materials》2013,14(2):397-404
Tetragonal CaF2-related-type t′-/Ce0.5Zr0.5)O2 phase was reduced at 773 K ≤ Tred. ≤ 1073 K to prepare precursors with various oxygen compositions: Ce2Zr2O712d /0.111 < δ < 0.379). Metastable tetragonal t′meta-(Ce0.5Zr0.5)O2 phases were prepared by oxidizing in O2 at 873 K the precursors, and subjected to evolved oxygen gas analysis by heating the samples at a constant rate. When the precursor was prepared at Tred: ? 773 K; i.e. δ ? 0:379; the oxygen release behavior of the tetragonal phase agreed approximately with that of the t′. For δ < 0.29, distinct features of the t′meta-(Ce0.5Zr0.5)O2 appeared in the XRD results and Raman spectra. The temperature exhibiting the maximum release rate of oxygen from the t′meta became lower with decreasing the d value. It could be concluded that the thermodynamic behavior of the t′meta is related closely to the precursor composition and becomes more unstable with decrease in the δ value. The t′ and t′meta phases with disordered arrangement of Ce and Zr ions may belong to the same space group; nevertheless, difference in the random arrays of the Ce and Zr ions was suggested on the basis of the present experimental results. 相似文献
16.
O.A. Plaksin Y. Takeda H. Amekura K. Kono N. Kishimoto 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2006,250(1-2):220-224
Optical transmission and ion-induced photon emission of SiO2 (silica glass), LiNbO3 and Al2O3 were measured during implantation of 60-keV Cu− or Au− ions. Conditions of stability of metal nanocomposites were determined and represented with the help of nonequilibrium phase diagrams. Formation of structures dynamically stable under ion bombardment diminished the efficiency of ion implantation for further accumulation of implants as in nanoparticles. Contributions from various radiation-induced processes (sputtering, radiation-induced diffusion, atomic collisions, electronic excitations, etc.) to formation of nanocomposites were evaluated. 相似文献
17.
Y. Takeda O.A. Plaksin J. Lu K. Kono N. Kishimoto 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2006,250(1-2):372-376
Optical nonlinearity and dispersion were studied for Cu nanoparticle composite. Negative Cu− ions with 60 keV were applied for implanting into SrTiO3 at a flux of 10 μA/cm2 up to a total fluence of 1 × 1017 ions/cm2. The steady-state optical spectrum of Cu-implanted SrTiO3 showed a surface plasmon resonance resulting from the formation of nanoparticles. Transient transmission and reflection were measured by the pump–probe method with a femtosecond laser system. Optical nonlinearity originated from Cu:SrTiO3 nanoparticle composite and from SrTiO3 matrix overlap, in measured transient spectra. The nonlinear component of Cu:SrTiO3 composite was extracted from the transient spectra with the difference of time response. Nonlinear dielectric coefficient and dispersion around the surface plasmon resonance were derived from extracted transient spectra. The dispersion was compared with a local electric field factor. 相似文献
18.
Nutritional state modulates the cell size of the fission yeast Schizosaccharomyces pombe, such that cells grown in rich medium are larger in size than those in poor medium. This signal is transduced partly through the cyclic AMP-dependent protein kinase cascade. However, little is known about how cyclic AMP interacts with the central cell cycle machinery, Cdc2, the cyclin-dependent kinase that induces mitosis. We show here that cyclic AMP regulates mitosis and cell size, in part, through regulation of protein stability of the Cdc2-activating phosphatase, Cdc25. However, our analysis demonstrates that cyclic AMP can negatively regulate mitosis independently of dephosphorylation of Cdc2 at Tyr(15). 相似文献
19.
Propagation of indentation fracture was firstly monitored on -SiC ceramics through a current drop accompanied by the decrease in current conduction area. The current decrease ratio before and after indentation during the constant voltage application was proportional to the crack area formed. However, during the indentation, the current anomalously increased even though the indentation crack propagated. This phenomena is probably due to the piezoresistance effect which has already reported in SiC single crystal. When bending stress was applied to -SiC ceramics, the current increase ratio was proportional to the bending strain. A fracture foreseeing system is proposed for -SiC ceramics in which initial crack monitoring without stress application and bending strain monitoring utilizing the piezoresistance effect are combined. 相似文献
20.