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121.
The external egg morphology of two stored-product pests, Stegobium paniceum and Lasioderma serricorne, is presented herein based on optical and scanning electron microscope micrographs. The diagnostic characteristics of the eggs of the pests, including the presence or absence of a micropyle, are described and discussed. Overall, several notable differences were observed between the eggs of these species in regard to their shape, size and surface structures. 相似文献
122.
Dynamic response characteristics of seismic isolation systems for building structures 总被引:1,自引:0,他引:1
Isolation is an effective method of reducing effects of seismic events on building structures. Steel-reinforced elastomeric
isolator (SREI) is one kind of isolation system which is used extensively, but there are some problems associated with its
use, such as cost and weight. Fiber-reinforced elastomeric isolator (FREI) has been developed in an attempt to solve the problems
of high cost and heavy weight for SREI. In this study, mechanical properties for the SREI and the FREI are investigated. Systematic
dynamic response analyses are performed for three different models such as a fixed based, an SREI based and an FREI based
low-story building structures. Two-dimensional and three-dimensional dynamic response analysis results for each model are
compared in terms of displacement, drift, acceleration and shear force in this study. In the two-dimensional dynamic response
analysis, the SREI and the FREI based structures are proven to be the more effective isolation systems against seismic events
by comparing with the fixed based one. As a result, the FREI has shown better isolation performances than that of the SREI.
Furthermore, to extract the characteristics of the FREI on building structure resisting the seismic effects, two models of
three-dimensional framed structure with fixed bases and FREI isolated bases are built, respectively. After the dynamic response
analysis of these two structures subjected to bi-directional ground motions, the analyzed results are compared with each other.
It is shown that the FREI could effectively absorb the seismic energy, and decreases the destructive effects acting on a building
structure due to ground horizontal motions that could occur in an earthquake.
This paper was recommended for publication in revised form by Associate Editor Seockhyun Kim
Beom-Soo Kang received his B.S. in Mechanical Engineering from Pusan National University in 1981 and his M.S. in Aerospace Engineering
from KAIST in 1983, Korea, respectively. He then received his Ph.D. from the University of California at Berkeley, USA, in
1990. Dr. Kang is currently a Professor at the Department of Aerospace Engineering at Pusan National University in Busan,
Korea. His research interests include seismic isolation, materials processing, FEM and flexible forming technology.
Tae-Wan Ku received his B.S., M.S. and Ph.D. in Aerospace Engineering from Pusan National University, Korea, in 1997, 1999 and 2003,
respectively. Dr. Ku is currently a research professor at the Department of Aerospace Engineering at Pusan National University
in Busan, Korea. His research interests include multi-stage deep drawing, flexible forming technology, and forming limit surface
theory. 相似文献
123.
Iwona Kuźniarska-Biernacka Ana R. Silva Ana P. Carvalho João Pires Cristina Freire 《Catalysis Letters》2010,134(1-2):63-71
The chiral Mn(III) salen complex (C1) was immobilised onto a natural clay (BEN) and a porous clay heterostructure (PCH) functionalised with 3-aminopropyltriethoxysilane (APTES). FTIR, XPS and Mn chemical analysis confirm the C1 anchorage in both materials, but with higher efficiency in BEN_APTES clay. The catalytic activity of C1@BEN_APTES and C1@PCH_APTES, was assessed in the epoxidation of styrene (sty) and ∝-methylstyrene (∝-Mesty) using NaOCl and m-chloroperoxybenzoic acid (m-CPBA)/N-methylmorpholine-N-oxide (NMO). Both materials behave as moderate catalysts, show high epoxide selectivity but low enantiomeric excesses. In the case of sty epoxidation with m-CBPA/NMO the C1@PCH_APTES catalyst showed the highest catalytic activity, whereas in ∝-Mesty epoxidation, the C1@PCH_APTES catalyst, although leading to lower substrate conversion than the BEN analogue, presented the lowest complex leaching. In all cases, the oxidant NaOCl had some destructive effect in the hybrid catalysts, highlighting the importance of a careful choice of catalyst and oxidant system. 相似文献
124.
Marie Kubešová Jan Ku?era 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,654(1):206-212
For many years the well-established Kayzero for Windows software for neutron activation analysis (NAA) using k0 standardization was the only commercial program available. Recently, the freeware k0-IAEA software has been launched by the International Atomic Energy Agency (IAEA). The software is based on an adapted Høgdahl convention in which the cadmium cut-off energy from the k0-formulas is removed. The holistic approach of γ-ray spectra evaluation is used which minimizes the user's interaction with the software.Several certified reference materials were analyzed with the k0-IAEA and Kayzero for Windows software using the same gamma-ray spectra obtained from several irradiation and counting modes. The results obtained were compared and evaluated in terms of precision, accuracy and detection limits. The work-flow procedures performed by the two software packages and the results obtained are discussed. 相似文献
125.
Chan-Li HsuehCheng-Hong Liu Bing-Hung ChenMing-San Lee Cheng-Yen ChenYu-Wen Lu Fanghei TsauJie-Ren Ku 《Journal of power sources》2011,196(7):3530-3538
Hydrolysis of sodium borohydride (NaBH4) is a promising method for on-board hydrogen supply to polymer electrolyte membrane fuel cells (PEMFC). This article presents an attempt to design a novel solid-state NaBH4 composite, which is made up of NaBH4 powder, Co2+/IR-120 catalyst and silicone rubber, for hydrogen generator. The silicone rubber can act as a stabilizer in the solid-state NaBH4 composite because of its surface hydrophobicity leading to reduced diffusion rate of water into the composite. The solid-state NaBH4 composite can produce hydrogen stably near 25 mL min−1 for at least 2 h without employment of any mechanical control system. Using the hydrogen generated from the solid-state NaBH4 composite, a 2 W PEMFC stack is successfully operated to power a cellular phone. 相似文献
127.
Mechanical properties and durability of PMMA impregnated mortar 总被引:1,自引:0,他引:1
Priya Nair Du Hyun Ku Chul Woo Lee Jung Soon Park Hun Young Park Won Mook Lee 《Korean Journal of Chemical Engineering》2010,27(1):334-339
Polymer impregnated concrete (PIC) is known to exhibit better strength and durability characteristics than the other classes
of polymer cement composites. In the work described herein the monomer was impregnated into cement mortar and polymerized
by two methods — the conventional thermal method and using microwaves. The mechanical properties and durability characteristics
of the samples and on exposure to chemical environments were then evaluated. The above studies revealed that the strengths
of PIC specimens were almost 2–3 times better than those of conventional cement mortars. The chemical resistance was also
found to be superior even on prolonged exposure to the chemical media. This may be attributed to the protective layer formed
by the polymer on the cement mortar, which prevents the external chemical media from interacting with the cement particles.
The properties of the PIC specimens prepared by both methods have also been compared and discussed in this paper. 相似文献
128.
The present article deals with fictitious domain methods for numerical realization of scalar variational inequalities with the Signorini type conditions on the boundary. Two variants are introduced and analyzed. A discretization is done by finite elements. It leads to a system of non-smooth, piecewise linear equations. This system is solved by the semismooth Newton method. Numerical experiments confirm the efficiency of this approach. 相似文献
129.
A. JuszaK. Anders A. Jastrz?bskaP. Polis A. OlszynaM. Ku? A. KunickiR. Piramidowicz 《Optical Materials》2011,33(10):1487-1491
In this work, we discuss structural and luminescent properties of Al2O3 nanopowders doped with Yb3+ ions prepared by a novel method, in which organic compounds were used as a solvent and lanthanide organic derivatives, served as a rare-earth ion source. The set of samples differing in activator concentrations and particle sizes was carefully studied by means of structural and optical characterization methods. In particular, the high resolution electron and transmission microscopy has been deployed together with X-ray diffraction technique to determine fundamental structural properties of nanopowders. The optical characterization was focused mainly on basic excitation and emission features and their sensitiveness on dopant concentration and the average nanoparticle size. 相似文献
130.
Ivan Ku
er 《Progress in Nuclear Energy》1999,34(4):355-359
A way of desribing multiple small angle scattering of light is by a modification of the Fokker-planck equation. While for non-relativistic particles fundamental solutions of the analogous equation are well known, their extension to light scattering appears difficult, except in the case with no space dependence. 相似文献