Slow deposition of Cu onto a clean unheated Fe{001} surface produced films with large amounts of defects, but still detectable crystallinity. Low-energy electron diffraction showed that the films contained regions with a (somewhat distorted) body-centered-cubic structure and the same or nearly the same lattice parameter as the underlying substrate. Auger-electron spectroscopy suggested that the crystalline regions were essentially pure Cu, thus allowing the conclusion that a metastable bcc modification of Cu has been realized, consistent with the predictions of total-energy band calculations reported elsewhere.
In Japan, Cryptomeria japonica pollen are scattered during each spring season.Daughter allergenic particles are released, which are smaller in size than their parent pollen grain and are abundant in a particle size below 1.1 μm in the atmosphere; nevertheless, Cryptomeria japonica pollen size is about 30 μm.Therefore, daughter allergenic particles of pollen are transported in the urban atmosphere for a long time after their release.In particular, the daily variation delays in the peaks of allergenic Cry j 1 concentrations of Cryptomeria japonica pollen compared with the peaks of airborne pollen counts were observed in high levels during one or two sunny days after rainfall.In addition, long range transportation of Asian dust from the East Asian continent, called yellow sand, was also found during the pollen scattering seasons in Japan, due to global warming.Therefore, the interaction between pollen and air pollutants, including yellow sand, should be of concern.Thus, in this study, the morphological change of Cryptomeria japonica pollen and the elution behavior of its allergenic contents (Cry j 1) were also investigated when in contact with simulated air polluted rain containing various crustal particles and/or secondary formed inorganic particles.As a result, pollen might burst at high humidity before www.witpress.com,
Garri from cassava is one of the most consumed foods in West Africa, hence this research was conducted to examine microplastics (MPs) and potentially toxic elements (PTEs) in garri from Nigeria (West Africa) and Japan. This is the first investigation on MPs in garri samples that has been reported in the literature. The study analyzed both packaged and unpackaged vended garri samples using microscopic/spectroscopic and X-ray fluorescence techniques for MPs and PTEs respectively. Microplastic particles in the garri samples ranged from (or were between) 2.00±2.00 - 175.00±25.16 particles/50 with > 90 % as fragments and consisted of polyacrylamide, polyethylene terepthalate, polyvinyl alcohol, high density polyethylene, polyvinyl chloride acrylonitrile, polyethylene chlorinated, polypropylene with silicate mix, polychloroprene and polyethylene chlorosulphonated. The mean concentration of PTEs raged from ND to 0.07 mg/g for Cr and Mn, 0.73 to 5.63 mg/g for Fe, ND to 0.57mg/g for Co, 0.23 to 1.21 mg/g for Ni, 0.15 to 1.53 mg/g for Cu, and 0.12 to 0.63 mg/g for Zn. However, their daily intake was low for both adult and children as with the MPs. The sources of MPs and PTEs were mainly from the garri production processes, atmospheric dusts and during packaging. The non-carcinogenic risk for all samples was low for MPs while in openly vended garri, Ni and Cr in all sample poses carcinogenic risks. There is a need to improve indigenous garri processing techniques to minimize contamination. This research emphasizes the critical necessity to understand the consequences of MPs on human health.
Abstract. The impacts of inhomogeneity of the oasis interior on the oasis self-maintenance mechanism are investigated by using the mesoscale model MM5 (the fifth-generation Pennsylvania State University National Center for Atmospheric Research (NCAR) mesoscale model) with satellite observations of land use types, vegetation fraction and surface-layer soil moisture from MODIS (Moderate Resolution Imaging Spectroradiometer) data. Four simulations were performed, among which the CTL (control simulation) and MOD (moderated simulation with parameters replaced by MODIS data) were used to validate the model results; EXP1 (experiment 1) and EXP2 (experiment 2) were designed to study the inhomogeneity of oasis interior. Results show that the changes of oasis heterogeneity influence the surface heat-flux partitioning, which leads to a larger "cold-wet" effect over the oasis. Vertical sections of humidity illustrate the existence of a moisture-inversion level, and the deeper moisture inversion of EXP1 and EXP2 further indicates that the relative homogeneity in the oasis interior helps produce stronger humidity inversion over the oasis, thus limiting evaporation. This is further verified by the analysis of the secondary circulation, which shows that the more homogeneous land surface conditions lead to stronger secondary circulation and less turbulent drafts over the oasis interior, playing a positive role in the oasis self-maintenance and development.
Abstract. Semi-volatile and intermediate-volatility organic
compounds (S–IVOCs) are considered critical precursors of secondary
organic aerosol (SOA), which is an important component of fine particulate
matter ( PM2.5 ). However, knowledge of the contributions of S–IVOCs
to SOA is still lacking in the Pearl River Delta (PRD) region,
southern China. Therefore, in this study, an emission inventory of S–IVOCs
in the PRD region was developed for the first time for the year 2010. The
S–IVOC emissions were calculated based on a parameterization method involving
the emission factors of POA (primary organic aerosol), emission ratios of
S–IVOCs to POA, and domestic activity data. The total emissions of S–IVOCs
were estimated to be 323.4 Gg, with major emissions from central cities in the
PRD, i.e., Guangzhou, Foshan, and Shenzhen. On-road mobile sources and
industries were the two major contributors of S–IVOC emissions, with
contributions of ∼42 % and ∼35 %,
respectively. Furthermore, uncertainties of the emission inventory were
evaluated through Monte Carlo simulation. The uncertainties ranged from
−79 % to 229 %, which could be mainly attributed to mass fractions of OC
(organic carbon) to PM2.5 from on-road mobile emissions and emission
ratios of IVOCs ∕ POA. The developed S–IVOC emission inventory was further
incorporated into the Weather Research and Forecasting with Chemistry
(WRF-Chem) model with a volatility basis-set (VBS) approach to improve the
performance of SOA simulation and to evaluate the influence of S–IVOCs on
SOA formation at a receptor site (Wan Qing Sha (WQS) site) in the PRD. The
following results could be obtained. (1) The model could resolve about
34 % on average of observed SOA concentrations at WQS after considering
the emissions of S–IVOCs, and 18 %–77 % with the uncertainties of the
S–IVOC emission inventory considered. (2) The simulated SOA over the PRD
region was increased by 161 % with the input of S–IVOC emissions, and it
could be decreased to 126 % after the reaction coefficient of S–IVOCs with
OH radical was improved. (3) Among all anthropogenic sources of S–IVOCs,
industrial emission was the most significant contributor of S–IVOCs for SOA
formation, followed by on-road mobile, dust, biomass burning, residential,
and off-road mobile emissions. Overall, this study firstly quantified
emissions of S–IVOCs and evaluated their roles in SOA formation over the PRD,
which contributes towards significantly improving SOA simulation and better
understanding of SOA formation mechanisms in the PRD and other regions in China.
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