19 research outputs found

    Synthesis of Hollow ZnSnO 3

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    Hollow ZnSnO3 nanospheres were synthesized by a hydrothermal method using ZnO nanospheres as the hard template and raw material simultaneously. The combined characterizations of X-ray diffraction (XRD), scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM) confirmed the successful preparation of hollow ZnSnO3 nanospheres. The gas-sensing results indicated that the sensor made from hollow ZnSnO3 nanospheres exhibited high sensitivity, good selectivity, and stability to ethanol at a low operating temperature of 200°C. The sensitivity was about 32 and the response and recovery time were about 4 s and 30 s for 100 ppm ethanol, respectively. The enhancement in gas-sensing properties was attributed to the hollow nanostructures and high specific surface areas of ZnSnO3

    Next Generation Additive Manufacturing: Tailorable Graphene/Polylactic(acid) Filaments Allow the Fabrication of 3D Printable Porous Anodes for Utilisation within Lithium-Ion Batteries

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    This is the peer reviewed version of the following article: Foster, C. W., Zou, G., Jiang, Y., Down, M. P., Liauw, C. M., Ferrari, A. G., Ji, X., Smith, G. C., Kellyand, P. J., Banks, C. E. (2019). Next Generation Additive Manufacturing: Tailorable Graphene/Polylactic(acid) Filaments Allow the Fabrication of 3D Printable Porous Anodes for Utilisation within Lithium-Ion Batteries. Batteries & Supercaps., 2(5), 448-453, which has been published in final form at https://doi.org/10.1002/batt.201800148. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingHerein, we report the fabrication and application of Li-ion anodes for utilisation within Li-ion batteries, which are fabricated via additive manufacturing/3D printing (fused depo- sition modelling) using a bespoke graphene/polylactic acid (PLA) filament, where the graphene content can be readily tailored and controlled over the range 1–40 wt. %. We demon- strate that a graphene content of 20 wt. % exhibits sufficient conductivity and critically, effective 3D printability for the rapid manufacturing of 3D printed freestanding anodes (3DAs); simplifying the components of the Li-ion battery negating the need for a copper current collector. The 3DAs are physicochemcally and electrochemically characterised and possess sufficient conductivity for electrochemical studies. Critically, it is found that if the 3DAs are used in Li-ion batteries the specific capacity is very poor but can be significantly improved through the use of a chemical pre-treatment. Such treatment induces an increased porosity, which results in a 200-fold increase (after anode stabilisation) of the specific capacity (ca. 500 mAhg-1 at a current density of 40 mAg-1). This work significantly enhances the field of additive manufacturing/3D printed graphene based energy storage devices demonstrating that useful 3D printable batteries can be realise

    Light-harvesting chlorophyll a/b-binding protein-coding genes in jatropha and the comparison with castor, cassava and arabidopsis

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    The Lhc (light-harvesting chlorophyll a/b-binding protein) superfamily represents a class of antennae proteins that play indispensable roles in capture of solar energy as well as photoprotection under stress conditions. Despite their importance, little information has been available beyond model plants. In this study, we presents a first genome-wide analysis of Lhc superfamily genes in jatropha (Jatropha curcas L., Euphorbiaceae), an oil-bearing plant for biodiesel purpose. A total of 27 members were identified from the jatropha genome, which were shown to distribute over nine out of the 11 chromosomes. The superfamily number is comparable to 28 present in castor (Ricinus communis, Euphorbiaceae), but relatively less than 35 in cassava (Manihot esculenta, Euphorbiaceae) and 34 in arabidopsis (Arabidopsis thaliana) that experienced one or two recent whole-genome duplications (WGDs), respectively. In contrast to a high number of paralogs present in cassava and arabidopsis, few duplicates were found in jatropha as observed in castor, corresponding to no recent WGD occurred in these two species. Nevertheless, 26 orthologous groups representing four defined families were found in jatropha, and nearly one-to-one orthologous relationship was observed between jatropha and castor. By contrast, a novel group named SEP6 was shown to have been lost in arabidopsis. Global transcriptome profiling revealed a predominant expression pattern of most JcLhc superfamily genes in green tissues, reflecting their key roles in photosynthesis. Moreover, their expression profiles upon hormones, drought, and salt stresses were also investigated. These findings not only improve our knowledge on species-specific evolution of the Lhc supergene family, but also provide valuable information for further studies in jatropha

    Hydrothermal synthesis of Zn-doped brookite TiO2 for enhanced visible-light-responsive photocatalytic performance

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    Brookite TiO _2 is considered as one of the excellent candidates in photo- or photo-/electro- chemical applications due to its unique crystalline structure and electronic properties. To achieve an enhanced visible-light-responsive brookite TiO _2 photocatalyst, Zn-doped brookite TiO _2 (ZBT) was in situ synthesized under hydrothermal conditions at 180 °C for 2 h in this research. X-ray diffraction (XRD) verified that the undoped sample was single-phase brookite TiO _2 , while the ZBT samples are mixtures of brookite and anatase because the incorporation of Zn caused brookite to anatase phase transformation. The average particle size of the ZBT samples was smaller than pure brookite TiO _2 and decreased with the increase of Zn amount, indicating that Zn doping inhibited the growth of crystallite. ZBT samples exhibited better photocatalytic activity for the degradation of methylene blue (MB) than pure brookite TiO _2 under visible light irradiation due to the effective separation of electrons and holes by Zn doping. Among the ZBT samples, the 5% ZBT sample exhibited the best photodegradation rate of MB (92.6%) under visible-light irradiation for 2 h, which was attributable to its small particle size (19.78 nm) and the large surface area (67.08 m ^−2 g ^−1 )

    Syntheses and proton conductivity of mesoporous Nd<sub>2</sub>O<sub>3</sub>-SiO<sub>2 </sub>and NdOCl-SiO<sub>2</sub> composites

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    Two mesoporous oxide composites of Nd2O3-SiO2 and NdOCl-SiO2 were synthesized using SBA-15 as a template and neodymium nitrate or neodymium chloride as a precursor. The porous Nd2O3-SiO2 with a SBA-15-like structure has amorphous walls and the porous NdOCl-SiO2 with a replicated structure of SBA-15 has crystalline walls. These porous materials were characterized by X-ray diffraction, transmission electron microscopy and nitrogen adsorption/desorption. They exhibited significant proton conductivities in the presence of moisture at low temperatures and the highest conductivity observed was 4.55 x 10(-4) S/cm at 47 A degrees C in wet air (RH = 28.6%).</p

    Catastrophic effects of sand mining on macroinvertebrates in a large shallow lake with implications for management

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    Sand mining is a human activity that is increasing in inland waters and has profound effects on entire aquatic ecosystems. However, current knowledge of the effects of sand mining on freshwater lake ecosystems remains limited, especially for biotic communities. Here, we investigated the responses of macroinvertebrates to indiscriminate sand mining in a large shallow lake of China. Our results indicated that sand mining significantly increased the content of suspended particulate matter, total nitrogen, total phosphorus and chlorophyll a in the water column both in the sand mining area and the area adjacent to the dredging activities. While there was significantly lower total nitrogen and the total phosphorus content of the sediment were observed in the sand mining area. In terms of benthic animals, there were reductions of the macroinvertebrate density and biomass of 89.80% and 99.54%, respectively, and there was a considerable decline of the majority of macroinvertebrate taxonomic taxa as well as biological traits observed in the sand mining area due to direct dredging-induced substrate deterioration and high turbidity water. Moreover, in the area adjacent to the dredging activities, dredging-induced high turbidity water also resulted in 28% and 79% decreases in macroinvertebrate density and biomass, respectively, with a significant decrease in the densities of Bivalvia and Polychaeta but an increase in the density of Crustacea. In terms of biological traits, species (e.g., Grandidierella sp. and Sphaerium lacustre) characterized by a small body size, short life cycle and dietary sources mainly from sediment were typically associated with the ecological condition of the indirect effects of the dredging activities. Taxa (e.g., Corbicula fluminea) with a larger body size and longer life cycle that are filter feeders should be favored by the ecological conditions of the reference sites. For biomonitoring of sand mining perturbations, a number of taxonomic and biological trait indicators were proposed in our study based on indicator value analysis, and the general applicability of trait-based indicators was highlighted. We also suggest that the biodiversity indices may be less suitable indicators of sand mining effects. Given the limited understanding of the responses of macroinvertebrates to sand mining in inland freshwaters, we believe that our results may provide important information for biomonitoring of sand mining activities and provide scientific management support to governments.peerReviewe

    The perception and interpretation of malaria among Chinese construction workers in sub-Saharan Africa: a qualitative study

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    Abstract Background Cooperation between China and Africa is deepening, and business, trade, and people-to-people exchanges are growing closer together, especially in the infrastructure construction field. At the same time, malaria has become a serious health concern for Chinese construction workers in Africa, who are at increased risk of infection and complications due to lack of immunity and exposure to high-transmission environments. One of the biggest challenges in fighting malaria is their lack of knowledge and misinterpretations about the disease, which can impact their need for interventions, adherence to treatments, and health services. This study aims to determine the perception and interpretation of malaria among Chinese construction workers in sub-Saharan Africa. Methods Semi-structured interviews were conducted with 20 Chinese construction workers in sub-Saharan Africa. Some early respondents initially made contact through two Chinese construction companies in Africa, while the rest of the participants were engaged via a snowball method by the early participants. NVivo10, a qualitative research data management software and a thematic approach, was used to analyze the data and create themes. In order to achieve the general study goals, an inductive content analysis was applied. Results The study classified participants' perceptions and interpretations of malaria into four categories: flu-like malaria, the rumors of malaria, the hard-to-explain confusion about malaria, and the special interpretation of malaria. Conclusion Malaria poses major health issues to Chinese construction workers in sub-Saharan Africa who lack immunity and live in an environment of high transmission. Their dearth of awareness and misunderstanding of malaria impacts their prevention and treatment behaviors and health outcomes. This study adopts qualitative methods to examine their perceptions and interpretations of malaria, which can serve as a source for future health management strategies
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