20 research outputs found

    Study on dehumidification performance of a multi-stage internal cooling solid desiccant adsorption packed bed

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    In this paper, the solid desiccant adsorption packed bed with a three-stage internal cooling (ICSPB) has been proposed to improve the dehumidification efficiency and make a comparison with that of non-internal cooling. To investigate the performance of the ICSPB, the dehumidification capacity, dehumidification efficiency, water content of solid desiccant, moisture ratio of solid desiccant, temperature of solid desiccant and inlet and outlet air temperature difference were discussed in different conditions of inlet air and supplying water temperature. It was found that the dehumidification performance of the bed with internal cooling could be improved greatly in the low temperature and low humidity conditions, while in the high temperature and humid, the improvement was not obvious. With internal cooling, the dehumidification efficiency and the water content of the solid desiccant could be improved 59.69% and 110.7%, respectively, and the temperature of solid desiccant could be reduced 2.2◩C when the ICSPB operated at the inlet air temperature of 20◩C, inlet humidity of 55%, and water temperature of 14◩C. Moreover, the dehumidification performance at each stage of ICSPB was studied. It was found that, the first stage played the most important role in the dehumidification process. In addition, the calculation models that can be used to predict the moisture ratio and the temperature of solid desiccant were established on the test results

    Tin Assisted Fully Exposed Platinum Clusters Stabilized on Defect-Rich Graphene for Dehydrogenation Reaction

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    Tin assisted fully exposed Pt clusters are fabricated on the core-shell nanodiamond@graphene (ND@G) hybrid support (a-PtSn/ND@G). The obtained atomically dispersed Pt clusters, with an average Pt atom number of 3, were anchored over the ND@Gsupport by the assistance of Sn atoms as a partition agent and through the Pt-C bond between Pt clusters and defect-rich graphene nanoshell. The atomically dispersed Pt clusters guaranteed a full metal availability to the reactants, a high thermal stability, and an optimized adsorption/desorption behavior. It inhibits the side reactions and enhances catalytic performance in direct dehydrogenation of n-butane at a low temperature of 450 °C, leading to \u3e98% selectivity toward olefin products, and the turnover frequency (TOF) of a-PtSn/ND@G is approximately 3.9 times higher than that of the traditional Pt3Sn alloy catalyst supported on Al2O3 (Pt3Sn/Al2O3)

    Safety analysis for integrated modular avionics based on blueprints

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    The Integrated Modular Avionics System (IMA) has been a core technology for the new generation of aircrafts in recent years. It consists of a set of reusable and interoperable common functional modules. However, the highly coupled relationship of resources makes it difficult to identify and control dangers. As an effective and efficient way, the blueprints are used to describe and manage the IMA system. Owing to the system management functions provided by the blueprints, we can accurately determine the system resources configuration status, which is very crucial for safety analysis. In this paper, we explore the possibilities to conduct safety analysis based on blueprints. A safety analysis method based on blueprints is proposed, which applies mathematical logic to describe the logical relationship between targets and resources provided by the blueprints and uses semi-tensor product of matrix theory to simplify the logical expressions. Based on the mathematical model, we can conduct the fail safety analysis and identify resources failures that may undermine the IMA system safety

    Safety analysis for integrated modular avionics based on blueprints

    No full text
    The Integrated Modular Avionics System (IMA) has been a core technology for the new generation of aircrafts in recent years. It consists of a set of reusable and interoperable common functional modules. However, the highly coupled relationship of resources makes it difficult to identify and control dangers. As an effective and efficient way, the blueprints are used to describe and manage the IMA system. Owing to the system management functions provided by the blueprints, we can accurately determine the system resources configuration status, which is very crucial for safety analysis. In this paper, we explore the possibilities to conduct safety analysis based on blueprints. A safety analysis method based on blueprints is proposed, which applies mathematical logic to describe the logical relationship between targets and resources provided by the blueprints and uses semi-tensor product of matrix theory to simplify the logical expressions. Based on the mathematical model, we can conduct the fail safety analysis and identify resources failures that may undermine the IMA system safety

    Reliability Modelling and Evaluation for LTD System Based on Load-Sharing Model

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    Based on power adding technology, the linear transformer driver (LTD) scheme is widely used to generate high-energy pulsed outputs and adopts a hierarchical and modular structure. Although robust design and fault analysis for basic components have been conducted recently, there is still a lack of enough reliability analysis studies of the whole system. Taking an actual LTD system as an object, this paper presents a system reliability model based on a load-sharing mechanism. A unified load-sharing rule structure is established and four typical rules corresponding to equal, linear, exponential, and local-equal relationships are discussed in detail while evaluating the impact of the load-sharing mechanism. Subsequently, simulation experiments are performed to illustrate the effects of different load-sharing rules as well as analyzing the system reliability in which we simultaneously propose a self-adaptive Monte Carlo simulation flow to achieve the sampling probability adjustment according to the random failure sequence. The simulation results can serve as a suggestion for further improvement of the system reliability. Moreover, the model framework and the simulation analysis method described here are universal and can be applied to evaluate the reliability of other LTD-based systems with tiny modifications

    Everybody Clean Up! : Group Cohesion and Social Loafing in Common Kitchens

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    The aim of this study was to examine whether increased awareness of group cohesion in common kitchens would reduce social loafing behaviour, as defined as leaving dishes in the sink for others to wash. Over the course of 4 weeks, measurements were taken twice a day in 3 common kitchens in the CIRS building at UBC, regarding the numbers of dishes left in the sinks and whether those dishes were rinsed. Each kitchen was assigned to either a control condition, involved a generic poster above the sink, or the experimental condition with a poster specifically intended to increase awareness of group cohesion. At the start of the third week, conditions of each common kitchen were switched, providing a within-subject design. We found there were no statistically significant differences between social loafing behavior and awareness of group cohesion, on either the number of dishes left in the sink (p = 0.383, α = 0.05) or the cleanliness of those dishes (p = 0.362, α = 0.05). Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”Arts, Faculty ofPsychology, Department ofUnreviewedUndergraduat

    lncRNA OTUD6B-AS1 Exacerbates As2O3-Induced Oxidative Damage in Bladder Cancer via miR-6734-5p-Mediated Functional Inhibition of IDH2

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    Arsenic trioxide (As2O3) is a promising effective chemotherapeutic agent for cancer treatment; however, how and through what molecular mechanisms the oxidative damage of As2O3 is controlled remains poorly understood. Recently, the involvement of dysregulated long noncoding RNA ovarian tumor domain containing 6B antisense RNA1 (lncRNA OTUD6B-AS1) in tumorigenesis is established. Here, for the first time, we characterize the regulation of As2O3 in the oxidative damage against bladder cancer via lncRNA OTUD6B-AS1. As2O3 could activate lncRNA OTUD6B-AS1 transcription in bladder cancer cells, and these findings were validated in a xenograft tumor model. Functional assays showed that lncRNA OTUD6B-AS1 dramatically exacerbated As2O3-mediated oxidative damage by inducing oxidative stress. Mechanistically, As2O3 increased levels of metal-regulatory transcription factor 1 (MTF1), which regulates lncRNA OTUD6B-AS1, in response to oxidative stress. Further, lncRNA OTUD6B-AS1 inhibited mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) expression by stabilizing miR-6734-5p, which contributed to cytotoxicity by enhancing oxidative stress. Together, our findings offer new insights into the mechanism of As2O3-induced oxidative damage and identify important factors in the pathway, As2O3/lncRNA OTUD6B-AS1/miR-6734-5p/IDH2, expanding the knowledge of activity of As2O3 as cancer treatment

    The recent progress of myeloid‐derived suppressor cell and its targeted therapies in cancers

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    Abstract Myeloid‐derived suppressor cells (MDSCs) are an immature group of myeloid‐derived cells generated from myeloid cell precursors in the bone marrow. MDSCs appear almost exclusively in pathological conditions, such as tumor progression and various inflammatory diseases. The leading function of MDSCs is their immunosuppressive ability, which plays a crucial role in tumor progression and metastasis through their immunosuppressive effects. Since MDSCs have specific molecular features, and only a tiny amount exists in physiological conditions, MDSC‐targeted therapy has become a promising research direction for tumor treatment with minimal side effects. In this review, we briefly introduce the classification, generation and maturation process, and features of MDSCs, and detail their functions under various circumstances. The present review specifically demonstrates the environmental specificity of MDSCs, highlighting the differences between MDSCs from cancer and healthy individuals, as well as tumor‐infiltrating MDSCs and circulating MDSCs. Then, we further describe recent advances in MDSC‐targeted therapies. The existing and potential targeted drugs are divided into three categories, monoclonal antibodies, small‐molecular inhibitors, and peptides. Their targeting mechanisms and characteristics have been summarized respectively. We believe that a comprehensive in‐depth understanding of MDSC‐targeted therapy could provide more possibilities for the treatment of cancer

    Simultaneous Anaerobic Ammonium Oxidation and Electricity Generation in Microbial Fuel Cell: Performance and Electrochemical Characteristics

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    In this study, a microbial fuel cell (MFC) that can achieve simultaneous anode anaerobic ammonium oxidation (anammox) and electricity generation (anode anammox MFC) by high-effective anammox bacteria fed with purely inorganic nitrogen media was constructed. As the influent concentrations of ammonium (NH4+-N) and nitrite (NO2−-N) gradually increased from 25 to 250 mg/L and 33–330 mg/L, the removal efficiencies of NH4+-N, NO2−-N and TN were over 90%, 90% and 80%, respectively, and the maximum volumetric nitrogen removal rate reached 3.01 ± 0.27 kgN/(m3·d). The maximum voltage and maximum power density were 225.48 ± 10.71 mV and 1308.23 ± 40.38 mW/m3, respectively. Substrate inhibition took place at high nitrogen concentrations (NH4+-N = 300 mg/L, NO2−-N = 396 mg/L). Electricity production performance significantly depended upon the nitrogen removal rate under different nitrogen concentrations. The reported low coulombic efficiency (CE, 4.09–5.99%) may be due to severe anodic polarization. The anode charge transfer resistance accounted for about 90% of the anode resistance. The anode process was the bottleneck for energy recovery and should be further optimized in anode anammox MFCs. The high nitrogen removal efficiency with certain electricity recovery potential in the MFCs suggested that anode anammox MFCs may be used in energy sustainable nitrogen-containing wastewater treatment
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