1,150 research outputs found

    Supported ITZ modification efficiencies via surface coating nanoparticles on aggregate and its influence on properties

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    In order to modify the porous interfacial transition zone (ITZ) microstructure of concrete more efficiently, a method of coating aggregate surfaces by using several nanoparticles was evaluated in this study. The compressive strength, chloride penetration of sound, and pre-loading samples were assessed in relation to the type of coating materials used (slag, nano-CaCO3, and nano-SiO2) and the designed coating thickness (5, 10, and 15 mu m). The ITZ microstructure was quantitatively determined via Backscattered electron (BSE) image analysis. Results showed that the overall performance of concrete is highly dependent on the coating materials and the designed coating thickness. Increasing the coating thickness of slag and nano-SiO2 could improve the chloride penetration resistance but decrease the compressive strength. Using nano-CaCO3 to coat the aggregate leads to a significant reduction in the properties of the so-prepared concrete. Though coating inert fine particles around aggregate could disturb the initial particle packing and modify the ITZ, it is not able to improve the overall concrete properties. Coating aggregate could determine the ITZ microstructure, especially within the region that is around 30 mu m away from aggregate surface

    Evidence That a Viral Replicase Protein Is Involved in the Disassembly of Tobacco Mosaic Virus Particlesin Vivo

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    AbstractTobacco mosaic virus (TMV) particles have been shown to undergo bidirectional disassembly when they are introduced into host cells. Approximately three-quarters of the genomic RNA (i.e., the 126-kDa and 183-kDa protein ORFs) is first uncoated in the 5′-to-3′ direction and the process is then completed by removal of coat protein molecules in the 3′-to-5′ direction. An effort was made to determine whether the 126-kDa protein or the 183-kDa protein, both of which are involved in replication of the viral RNA, is required for the second part of the disassembly reaction. It was shown that progeny negative-strand viral RNA begins to be produced in inoculated cells at about the same time that 3′-to-5′ disassembly is initiated thus suggesting that the two processes may be coupled. Particles containing mutant forms of the viral RNA in which large sections of the 126-kDa and 183-kDa protein ORFs were missing were not disassembled in the 3′-to-5′ direction when they were introduced into cells. However, they were disassembled when the inoculum contained purified TMV RNA from which, presumably, the two functional proteins could be translated. Particles containing mutants of the RNA from which a few codons had been deleted in or near conserved regions in the 126-kDa protein ORF also did not undergo 3′-to-5′ disassembly unless mixed with wild type viral RNA prior to inoculation. These results suggest that the 126-kDa and/or 183-kDa protein plays a role in the completion of disassembly of TMV particles at the onset of the infection process

    Linear implicit approximations of invariant measures of semi-linear SDEs with non-globally Lipschitz coefficients

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    This article investigates the weak approximation towards the invariant measure of semi-linear stochastic differential equations (SDEs) under non-globally Lipschitz coefficients. For this purpose, we propose a linear-theta-projected Euler (LTPE) scheme, which also admits an invariant measure, to handle the potential influence of the linear stiffness. Under certain assumptions, both the SDE and the corresponding LTPE method are shown to converge exponentially to the underlying invariant measures, respectively. Moreover, with time-independent regularity estimates for the corresponding Kolmogorov equation, the weak error between the numerical invariant measure and the original one can be guaranteed with an order one. Numerical experiments are provided to verify our theoretical findings.Comment: 45 pages, 7 figure
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