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Magnetic properties of conventional grain-oriented electrical steel sheets are different in various directions. In the present paper, Epstein standard samples were cut with different angles to rolling direction, and the corresponding magnetic properties of samples were tested. Results show that the hard magnetization direction to the rolling direction is around 60°. Conventional elliptical models are not accurate to simulate permeability at all magnetic intensities, and parabolic and hybrid models with high accuracy are proposed to simulate relations between permeability and magnetization direction. When magnetic intensity is no less than 10 000 A/m, hybrid model can be used, and when magnetic intensity is less than 10 000 A/m, parabolic model should be applied. Two-stage relation model of permeability and magnetization angles is of significance in improving the accuracy of electromagnetic engineering calculations of electrical steel and can be applied in industrial applications. [ABSTRACT FROM AUTHOR]

Ecosystem modelling is a useful tool for gaining insight and quantifying the carbon exchange between the atmosphere and terrestrial ecosystems. This study examines how well Forest-DNDC (a process-based biogeochemical model for forests/wetlands) estimates carbon dioxide (CO2) fluxes from Canadian boreal forests and peatlands. We also evaluate the appropriateness in using Forest-DNDC to establish the baseline conditions of CO2 fluxes before land-use change. Two mature black spruce forests and two ombrotrophic bogs were selected for comparisons between modelled and measured CO2 fluxes. Two vegetation parameters in Forest-DNDC were optimized, and a hydrologic parameter was calibrated for the CO2 flux simulations. The daily GPP (gross primary production) and ER (ecosystem respiration) simulations from all the study sites were in close agreement with the observations (r² for GPP and ER equal 0.79-0.86 and 0.86-0.87, respectively). The results of this study show that Forest-DNDC is useful in establishing baseline exchanges for boreal ecosystems prior to land-use change. [ABSTRACT FROM AUTHOR]

Poly(styrene-co-divinylbenzene)/organic montmorillonite (OMMT) nanocomposites were prepared by suspension polymerization. OMMT was prepared by ion exchange method between sodium montmorillonite (SMMT) and cetyltrimethyl ammonium bromide (CTAB) in an aqueous solution. The character and structure of OMMT was revealed by XRD and FT-IR. The microstructure of polymer/OMMT nanocomposites was characterized by XRD, TEM and SEM. The thermal stability of polymer/OMMT nanocomposites was studied by TG and DTG. Also the effect of the amount of OMMT and divinylbenzene (DVB) on the thermal stability of polymer/OMMT nanocomposites has been discussed in this paper. It was observed that the crosslinked polymer/clay nanocomposites exhibited better thermal stability than pure polystyrene and polystyrene/clay nanocomposites under the experimental conditions. [ABSTRACT FROM AUTHOR]

The photocatalytic decolorization of methylene blue (MB) was studied using Ag-BiVO4 prepared by deposition. The present Ag strongly enhanced photocatalytic decolorization efficiency of MB, being three-times higher than that of undoped BiVO4 under UV-light irradiation. The influences of calcination temperature on Ag-BiVO4, Ag content of Ag-BiVO4, dosage of photocatalyst, initial MB concentration and pH were studied. The results indicated that more than 95% MB (initial concentration 10 mg/L) could be removed at pH 7.16 under UV-light irradiation for 2 hr, when 2 g/L Ag-BiVO4 with 3 wt.% of Ag was used. [ABSTRACT FROM AUTHOR]

The article offers information on the denitrification models and approaches for terrestrial and aquatic ecosystems. A discussion on the current approaches used for modeling denitrification, as well as the nitrogen (N) cycling processes for both ecosystems are enumerated. The approaches described, creates predictions for microbial dynamics by representing an environment where denitrification is likely to occur. The models used in both ecosystems indicate the importance of denitrification of the N cycle. Further, current models need more development and testing to eliminate the uncertainties associated.

The article analyzes the impacts of mitigation alternatives, management of water, fertilizer, and rice straw, on net greenhouse gas (GHG) emissions including that of carbon dioxide, methane, and nitrous oxide fluxes. Assessments of the effectiveness of mitigation of GHG emissions from paddy rice systems have been analyzed based on field studies. Extrapolation of the mitigation potential of alternative management practices from field studies to a national scale may be enhanced by spatially explicit process models, like the DeNitrification and DeComposition (DNDC) model. The results of this study provide insight into potential for GHG emissions reductions for other parts of the world with rice or upland agriculture.