33 research outputs found

    Integrated motor drives: state of the art and future trends

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    With increased need for high power density, high efficiency and high temperature capabilities in Aerospace and Automotive applications, Integrated Motor Drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This paper reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics (PE) position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the Matrix converter, 2-level Bridge, 3-level NPC and Multiphase full bridge converters are also reviewed. Wide band gap devices like SiC and GaN and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented

    PESFOR-W: Improving the design and environmental effectiveness of woodlands for water Payments for Ecosystem Services

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    ABSTRACT: The EU Water Framework Directive aims to ensure restoration of Europe?s water bodies to ?good ecological status? by 2027. Many Member States will struggle to meet this target, with around half of EU river catchments currently reporting below standard water quality. Diffuse pollution from agriculture represents a major pressure, affecting over 90% of river basins. Accumulating evidence shows that recent improvements to agricultural practices are benefiting water quality but in many cases will be insufficient to achieve WFD objectives. There is growing support for land use change to help bridge the gap, with a particular focus on targeted tree planting to intercept and reduce the delivery of diffuse pollutants to water. This form of integrated catchment management offers multiple benefits to society but a significant cost to landowners and managers. New economic instruments, in combination with spatial targeting, need to be developed to ensure cost effective solutions - including tree planting for water benefits - are realised. Payments for Ecosystem Services (PES) are flexible, incentive-based mechanisms that could play an important role in promoting land use change to deliver water quality targets. The PESFOR-W COST Action will consolidate learning from existing woodlands for water PES schemes in Europe and help standardize approaches to evaluating the environmental effectiveness and cost-effectiveness of woodland measures. It will also create a European network through which PES schemes can be facilitated, extended and improved, for example by incorporating other ecosystem services linking with aims of the wider forestscarbon policy nexus

    The mitochondrial genome of Vulgichneumon sp. (Hymenoptera: Ichneumonidae)

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    The Vulgichneumon sp. belongs to the subfamily Ichneumoninae of Ichneumonidae. The mitogenome (GenBank accession number: MN178162) of Vulgichneumon sp. was sequenced, the first representative of the mitogenome of the subfamily. The nearly complete mitogenome is 15,306 bp totally, consisting of 13 protein-coding genes, 2 rRNAs and 22 transfer RNAs. The nucleotide composition biases toward A and T, which together made up 83.6% of the entirety. Bayesian inference analysis supported the monophyly of Evanioidea, Chalcidoidea, Platygastroidea, Proctotrupoidea, Ceraphronoidea, and Ichneumonoidea. This result also suggested that the clade that contains other six superfamilies was the sister group to the clade that consist of Trigonaloidea, Megalyroidea and Ichneumonoidea

    A Secret Sharing-Based Key Management in Hierarchical Wireless Sensor Network

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    Wireless sensor networks (WSNs) are subject to various attacks because of the vulnerable environment, limited recourse, and open communication channel. To protect WSNs, in this paper, we present a Secret sharing-based key management (SSKM). SSKM utilizes the advantages of hierarchical architecture and adopts two-level key management and authentication mechanism, which can efficiently protect the allover network communication security and survivability. Different from previous works, the SSKM distributes keys based on secret sharing mechanism by the clustered architecture, which not only localizes the key things but also keeps scalability. The SSKM provides various session keys, the network key for base station (BS) and cluster heads (CHs); the cluster key between the cluster head and member nodes. The SSKM dynamically generates different keys based on different polynomials from BS in different periods which can protect the network from the compromised nodes and reduce the high probability of the common keys. The security analysis shows that the SSKM can prevent several attacks effectively and reduce the energy consumption

    Mixed-Surfactant-Assisted Synthesis of Dual-Phase Li4Ti5O12-TiO2 Hierarchical Microspheres as High-Performance Anode Materials for Li-Ion Batteries

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    A mixed-surfactant-assisted method was developed to synthesize dual-phase Li4Ti5O12-TiO2 hierarchical microspheres. The ratio of anionic/cationic surfactant could regulate the primary structure morphology and the dual-phase ratio of the final product, in which the primary structure morphology could be stacked nanosheets, small nanoparticles, or large nanoparticles. The sample with a primary structure morphology of small nanoparticles had the highest specific surface area of 79.38 m(2) g(-1) and the best electrochemical performance because of its high Li+ migration rate, low polarization, and appropriate TiO2 content. Its capacity reached 153.5 mA h g(-1) at a current rate of 40 C, and it retained nearly 100 % of its capacity after 100 cycles. A self-assembly mechanism of the mixed surfactant was highlighted to explain the formation of hierarchical microspheres. The physical and electrochemical properties of obtained material were correlated effectively

    Effects of Body Mass Index, Waist Circumference, Waist-to-Height Ratio and Their Changes on Risks of Dyslipidemia among Chinese Adults: The Guizhou Population Health Cohort Study

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    This study aimed to assess the effects of different anthropometric indices and their changes on the risk of incident dyslipidemia among the Chinese population. From the Guizhou population health cohort study, 2989 Chinese adults without dyslipidemia at baseline were followed up. Anthropometric parameters including waist circumference (WC), body mass index (BMI), waist-to-height ratio (WHtR), and their changes in the latter two indices, and serum lipids were tested after at least 8 h fasting. Hazard ratio (HR), adjusted hazard ratio (aHR), and 95% confidential interval (CI) were calculated to estimate the association between anthropometric parameters and dyslipidemia risk using multivariate Cox regression. A total of 2089 (69.98%) new dyslipidemia cases were identified over an average follow-up of 7.0 years. Baseline BMI (aHR = 1.12, 95%CI 1.01, 1.23) and WHtR (aHR = 1.06, 95%CI 1.00, 1.13) were positively associated with higher risks of incident dyslipidemia but not WC. Each 5.0 kg/m2 increment of BMI or 0.05-unit increment of WHtR was significantly associated with 43% or 25% increased risk of incident dyslipidemia, respectively. The aHRs (95%CI) of incident dyslipidemia for subjects maintaining or developing general obesity were 2.19 (1.53, 3.12) or 1.46 (1.22, 1.75), and 1.54 (1.23, 1.82) or 1.30 (1.06, 1.60) for subjects maintaining or developing abdominal obesity, respectively. Linear trends for aHRs of BMI, WHtR change, and BMI change were observed (p for trend: 0.021, <0.001, <0.001, respectively). BMI, WHtR, and their changes were closely associated with the incidence of dyslipidemia for Chinese adults. Loss in BMI and WHtR had protective effects on incident dyslipidemia, whereas gain of BMI or WHtR increased the dyslipidemia risk. Interventions to control or reduce BMI and WHtR to the normal range are important for the early prevention of dyslipidemia, especially for participants aged 40 years or above, male participants, and urban residents with poor control of obesity

    C5aR1 blockade reshapes immunosuppressive tumor microenvironment and synergizes with immune checkpoint blockade therapy in high-grade serous ovarian cancer

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    ABSTRACTHigh-grade serous ovarian cancer (HGSC), with a modest response to immune checkpoint blockade (ICB) targeting PD-1/PD-L1 monotherapy, is densely infiltrated by M2-polarized tumor-associated macrophages (TAMs) and regulatory T (Treg) cells. The complement C5a/C5aR1 axis contributes to the programming of the immunosuppressive phenotype of TAMs in solid tumors and represents a promising immunomodulatory target for treating HGSCs. Here, we aimed to identify the relevance of C5aR1 in prognosis, immune microenvironment, and immunotherapy response in HGSCs. The expression and relationship of C5aR1 with tumor-infiltrating immune cells were assessed by immunohistochemistry and flow cytometry in the training cohort (n = 120) and fresh HGSC tissues (n = 36). Transcriptomic analyses of the xenografts delineated the mechanisms driving the immunomodulatory activity of PMX53, an orally bioavailable C5aR1 inhibitor. Therapeutic relevance was confirmed in ex vivo tumor cultures and The Cancer Genome Atlas (TCGA) datasets. C5aR1 expression independently predicted dismal prognosis and was linked to the immunoevasive subtype of HGSC, characterized by increased infiltration of pro-tumor cells (Treg cells, M2-polarized macrophages, and neutrophils) and impaired CD8+T functions. PMX53 antagonized subcutaneous tumor growth, modulated immunosuppressive mechanisms and synergized with aPD-1 in several tumor types. Single-cell RNA-seq analysis revealed predominant C5aR1 expression in TAMs, with an immunosuppressive-related expression signature in C5aR1+TAMs. Furthermore, the combination of C5aR1 and PD-L1 was associated with specific molecular characteristics and matched clinical response annotations. Therefore, the abundance of C5aR1 could predict an inferior prognosis in HGSCs, and incorporating PD-L1 may serve as a novel predictive biomarker to guide therapeutic options
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