749 research outputs found

    CeO2 based catalysts for the treatment of propylene in motorcycle's exhaust gases

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    In this work, the catalytic activities of several single metallic oxides were studied for the treatment of propylene, a component in motorcycles' exhaust gases, under oxygen deficient conditions. Amongst them, CeO2 is one of the materials that exhibit the highest activity for the oxidation of C3H6. Therefore, several mixtures of CeO2 with other oxides (SnO2, ZrO2, Co3O4) were tested to investigate the changes in catalytic activity (both propylene conversion and CO2 selectivity). Ce0.9Zr0.1O2, Ce0.8Zr0.2O2 solid solutions and the mixtures of CeO2 and Co3O4 was shown to exhibit the highest propylene conversion and CO2 selectivity. They also exhibited good activities when tested under oxygen sufficient and excess conditions and with the presence of co-existing gases (CO, H2O)

    EFFECT OF REDUCED CARBON SUPPLY ON ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL AND DENITRIFICATION

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    Joint Research on Environmental Science and Technology for the Eart

    Policy Learning for Off-Dynamics RL with Deficient Support

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    Reinforcement Learning (RL) can effectively learn complex policies. However, learning these policies often demands extensive trial-and-error interactions with the environment. In many real-world scenarios, this approach is not practical due to the high costs of data collection and safety concerns. As a result, a common strategy is to transfer a policy trained in a low-cost, rapid source simulator to a real-world target environment. However, this process poses challenges. Simulators, no matter how advanced, cannot perfectly replicate the intricacies of the real world, leading to dynamics discrepancies between the source and target environments. Past research posited that the source domain must encompass all possible target transitions, a condition we term full support. However, expecting full support is often unrealistic, especially in scenarios where significant dynamics discrepancies arise. In this paper, our emphasis shifts to addressing large dynamics mismatch adaptation. We move away from the stringent full support condition of earlier research, focusing instead on crafting an effective policy for the target domain. Our proposed approach is simple but effective. It is anchored in the central concepts of the skewing and extension of source support towards target support to mitigate support deficiencies. Through comprehensive testing on a varied set of benchmarks, our method's efficacy stands out, showcasing notable improvements over previous techniques.Comment: Accepted by AAMAS 2024 as a full pape

    Architecture Parallel for the Renewable Energy System

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    This chapter present one possible evolution is the parallel topology on the high-voltage bus for the renewable energy system. The system is not connected to a chain of photovoltaic (PV) modules and the different sources renewable. This evolution retains all the advantages of this system, while increasing the level of discretization of the Maximum Power Point Tracker (MPPT). So it is no longer a chain of PV modules that works at its MPPT but each PV module. In addition, this greater discretization allows a finer control and monitoring of operation and a faster detection of defects. The main interest of parallel step-up voltage systems, in this case, lies in the fact that the use of relatively high DC voltages is possible in these architectures distributed

    DNA barcoding for identification of some fish species (Carangidae) in Vietnam coastal area

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    Carangidae family has got about 148 species belonging to 32 genera. In Vietnam, Carangidae is of high commercial value and playing an important role in the ecosystem. In the context Vietnam has received yellow card for seafood since Nov. 2017 by the EU, in which one of the main reasons was related to the restriction of traceability. In this study, DNA barcoding technique of mitochondrial cytochrome oxidase I (COI) gene was used to classify 56 specimens of Carangidae from three coastal areas (Northern, Central and Southern) in Vietnam to evaluate the effectiveness compared to the morphological classification method. Results showed that 21 species belonging to 16 genera were determined by the COI barcode while 18 species (16 genera) were determined when using morphological method. Seriola quinqueradiata and Trachinotus anak were newly recorded in Vietnam. From 56 sequences with 660 bp of mtDNA (COI), total 27 haplotypes were detected; haplotype diversity (h) and nucleotide diversity (π) were 0.903 ± 0.00060 and 0.14%, respectively. The DNA barcodes of COI gene of 21 species in Carangidae which were developed in this study could be used as a basis for comparison and traceability of their products. In addition, the results showed the high potentiality in using COI barcode to identify Carangidae fish in Vietnam

    AN EVIDENCE FOR THE CONTRIBUTION OF ANAMMOX PROCESS IN NITROGEN REMOVAL FROM GROUNDWATER

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    Joint Research on Environmental Science and Technology for the Eart

    CAMELLIA HOABINHENSIS (THEACEAE: SECT. CHRYSANTHA), A NEW YELLOW-FLOWERED SPECIES FROM NORTHERN VIETNAM

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    A new species, Camellia hoabinhensis (section Chrysantha, Theaceae), is described and illustrated based on specimens collected from a lowland forest on limestone hills in Hoa Binh Province, northern Vietnam. The species is characterized by its small habit to 4.5 m tall, large flowers 9.0–9.5 cm in diameter with 18–19 light yellow petals, and hairy filaments, ovaries, and styles. A comparison of the new species with similar species, C. euphlebia, C. impressinervis, C. phanii, and C. velutina, is provided. The IUCN conservation status of the proposed species is Data Deficient (DD)

    Evaluation of Asaoka and Hyperbolic Methods for Settlement Prediction of Vacuum Preloading Combined with Prefabricated Vertical Drains in Soft Ground Treatment

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    This study evaluated the use of the Asaoka and hyperbolic methods to estimate the ultimate settlement of soft ground treated by vacuum preloading combined with prefabricated vertical drains. For this aim, a large-scale physical laboratory model was constructed. The model was a reinforced-tempered glass box containing a soil mass with dimensions of 2.0 × 1.0 × 1.2 m (length × width × depth). Physical models of this scale for the same purpose are rare in the literature. The soil was taken from a typical coastal region in Dinh Vu Hai Phong, Vietnam. The surface settlement near and between the two drains was measured right after the vacuum preloading started. Important properties of the soil were tested to evaluate the effectiveness of the treatment method. The measured settlement was used in the Asaoka and hyperbolic methods to predict the potential ultimate settlement. The results showed the superiority of the vacuum consolidation approach in improving fundamental engineering properties of soft soil. Furthermore, the ultimate settlement predicted by both methods showed a good agreement with the measured value, proving that the Asaoka and hyperbolic methods are suitable for the estimation of the ultimate settlement of soft soil treated with vacuum consolidation
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