5,462 research outputs found

    Estimating Cloud and Aerosol UV Modification Factors Based on Spectral Measurement from the Brewer Spectrophotometer

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    Cloud and aerosol modification factors are investigated in the spectral range of ultraviolet (UV) to correct for cloud and aerosol extinction effects from clear sky irradiance. The cloud modification factor (CMF) and aerosol modification factor (AMF) are estimated using radiative transfer model (RTM) simulations and ground-based observations in Seoul, Korea. The modification factors show a spectral dependence within the spectral range of 300 to 360 nm, which is the range used to estimate erythemal UV. The CMF and AMF values are estimated with high spectral resolution with considerations of solar zenith angle (SZA), cloud/aerosol amount, and total ozone variation. From the simulation studies, the variation in the CMFs within the spectral range of 300-360 nm is estimated to be 0.031-0.055, which is twice as large as the decrease in CMFs resulting from a SZA increase of 10 degrees. In addition, the CMFs estimated from observational data show significant spectral dependence, varying from 2.5% to 10.0%. Because of the small aerosol optical depth (AOD) value, however, the variation in the AMF calculated from simulations is estimated to be between 0.007 and 0.045, indicating lower spectral dependence than the CMF. Furthermore, the spectral difference in the AMF calculated from observational data is insignificant relative to the daily-averaged total ozone error and uncertainties related to the reference irradiance spectrum under aerosol-free conditions

    Nicotiana benthamiana protein, NbPCIP1, interacting with Potato virus X coat protein plays a role as susceptible factor for viral infection

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    AbstractThe interactions of viral coat protein (CP) and host factors play an important role in viral replication and/or host defense mechanism. In this study, we constructed Nicotiana benthamiana cDNA library to find host factors interacting with Potato virus X (PVX) CP. Using yeast two-hybrid assay, we screened 3.3Ɨ106 independent yeast transformants from N. benthamiana cDNA library and identified six positive clones. One positive clone, named PVX CP-interacting protein 1 (NbPCIP1), is a plant-specific protein with homologue in N. tabacum (GenBank accession no. AB04049). We confirmed the PVX CPā€“NbPCIP1 interaction using yeast-two hybrid assay in yeast, proteinā€“protein binding assay in vitro, and bimolecular fluorescent complementation assay in planta. Quantitative real-time RT-PCR analysis showed that the mRNA level of NbPCIP1 increased in PVX-infected N. benthamiana plants as compared to that of healthy plants. The green fluorescent protein (sGFP)-fused NbPCIP1 (NbPCIP1-sGFP) was localized in ER or ER-associated granular-like structure of cells. When we co-express NbPCIP1-sGFP and red fluorescent protein (RFP)-fused PVX CP (PVX CP-RFP), which were introduced by transiently expressing these proteins in N. benthamiana protoplasts and epidermal cells, however, we observed the co-localization of these proteins in the inclusion body-like complex in areas surrounding nucleus. Transient over-expression and transgene silencing of NbPCIP1 assay analysis indicated that NbPCIP1 plays a critical role in viral replication during PVX infection in host plant

    Development of Pd Alloy Hydrogen Separation Membranes with Dense/Porous Hybrid Structure for High Hydrogen Perm-Selectivity

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    For the commercial applications of hydrogen separation membranes, both high hydrogen selectivity and permeability (i.e., perm-selectivity) are required. However, it has been difficult to fabricate thin, dense Pd alloy composite membranes on porous metal support that have a pore-free surface and an open structure at the interface between the Pd alloy films and the metal support in order to obtain the required properties simultaneously. In this study, we fabricated Pd alloy hydrogen separation membranes with dense/porous hybrid structure for high hydrogen perm-selectivity. The hydrogen selectivity of this membrane increased owing to the dense and pore-free microstructure of the membrane surface. The hydrogen permeation flux also was remarkably improved by the formation of an open microstructure with numerous open voids at the interface and by an effective reduction in the membrane thickness as a result of the porous structure formed within the Pd alloy films
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