68 research outputs found

    In-situ Grown SnS2 Nanosheets on rGO as an Advanced Anode Material for Lithium and Sodium Ion Batteries

    Get PDF
    SnS2 nanosheets/reduced graphene oxide (rGO) composite was prepared by reflux condensation and hydrothermal methods. In this composite, SnS2 nanosheets in-situ grew on the surface of rGO nanosheets. The SnS2/rGO composite as anode material was investigated both in lithium ion battery (LIB) and sodium ion battery (SIB) systems. The capacity of SnS2/rGO electrode in LIB achieved 514 mAh g−1 at 1.2 A g−1 after 300 cycles. Moreover, the SnS2/rGO electrode in SIB delivered a discharge capacity of 645 mAh g−1 at 0.05 A g−1; after 100 cycles at 0.25 A g−1, the capacity retention still keep 81.2% relative to the capacity of the 6th cycle. Due to the introduction of rGO in the composite, the charge-transfer resistance became much smaller. Compared with SnS2/C electrode, SnS2/rGO electrode had higher discharge capacity and much better cycling performance

    Systematic meta-analyses and field synopsis of genetic association studies in colorectal adenomas

    Get PDF
    BackgroundLow penetrance genetic variants, primarily single nucleotide polymorphisms, have substantial influence on colorectal cancer (CRC) susceptibility. Most CRCs develop from colorectal adenomas (CRA). Here we report the first comprehensive field synopsis that catalogues all genetic association studies on CRA, with a parallel online database [http://www.chs.med.ed.ac.uk/CRAgene/].MethodsWe performed a systematic review, reviewing 9750 titles, and then extracted data from 130 publications reporting on 181 polymorphisms in 74 genes. We conducted meta-analyses to derive summary effect estimates for 37 polymorphisms in 26 genes. We applied the Venice criteria and Bayesian False Discovery Probability (BFDP) to assess the levels of the credibility of associations.ResultsWe considered the association with the rs6983267 variant at 8q24 as 'highly credible', reaching genome-wide statistical significance in at least one meta-analysis model. We identified 'less credible' associations (higher heterogeneity, lower statistical power, BFDP > 0.02) with a further four variants of four independent genes: MTHFR c.677C>T p.A222V (rs1801133), TP53 c.215C>G p.R72P (rs1042522), NQO1 c.559C>T p.P187S (rs1800566), and NAT1 alleles imputed as fast acetylator genotypes. For the remaining 32 variants of 22 genes for which positive associations with CRA risk have been previously reported, the meta-analyses revealed no credible evidence to support these as true associations.ConclusionsThe limited number of credible associations between low penetrance genetic variants and CRA reflects the lower volume of evidence and associated lack of statistical power to detect associations of the magnitude typically observed for genetic variants and chronic diseases. The CRA gene database provides context for CRA genetic association data and will help inform future research directions

    SOC estimation of rechargeable batteries

    No full text
    In order to ensure that the energy inside the battery is made good use for supplying the portable product and that the risk of damaging the batteries is minimized, the state-of-charge (SOC), which cannot be measured directly, of the battery needs to be accurate. In this thesis, two kinds of estimators, the EKF and the UKF, were introduced and tested in Matlab environment. First, an accurate battery model was quoted and several verified tests were conducted in order to introduce the model at length. The voltage, measured SOC and current data was also obtained in this process for the next estimation step. Then, the EKF and the UKF algorithms were introduced. Experiments were then conducted in order to verify the algorithms in different kinds of situations. The results showed that when the conditions were not ideal, the UKF could perform better than the EKF.Master of Science (Power Engineering

    CMOS differential logic with signal-independent power consumption

    No full text
    Power consumption is always the key problem for the digital circuit design. Also, information leaked by hardware implementation is always the problem for the encryption. Many functional logics have been proposed to solve the problems, including Sense Amplifier Based Logic (SABL), Delay-Based Dual-Rail Precharge Logic (DDPL) and Three-phase Dual-Rail Precharge Logic (TDPL). However, the power consumption of these logic gates was less concerned by the designers. This paper focused on the power consumption of different logic gates. By simulating the dynamic logic circuit and dynamic differential circuit in Cadence, the values of power consumption of those circuits were got and compared. By changing the voltage value of the power supply, a conclusion could be made that reducing the voltage of power supply would reduce the power consumption of the circuits. However, this would also result in longer delay time. Hence, a compromise should be made considering the different function of the logics. For those three functional logic circuits, the power consumption values of them were also got and compared to get a better logic with better performance. It was hard to judge which one was better. One should choose the logic depending on the specific needs.Bachelor of Engineerin

    Beyond Apprenticeship: Knowledge Brokers and Sustainability of Apprentice-Based Clusters

    No full text
    Knowledge learning and diffusion have long been discussed in the literature on the dynamics of industrial clusters, but recent literature provides little evidence for how different actors serve as knowledge brokers in the upgrading process of apprentice-based clusters, and does not dynamically consider how to preserve the sustainability of these clusters. This paper uses empirical evidence from an antique furniture manufacturing cluster in Xianyou, Fujian Province, in southeastern China, to examine the growth trajectory of the knowledge learning system of an antique furniture manufacturing cluster. It appears that the apprentice-based learning system is crucial during early stages of the cluster evolution, but later becomes complemented and relatively substituted by the role of both local governments and focal outsiders. This finding addresses the context of economic transformation and provides empirical insights into knowledge acquisition in apprentice-based clusters to question the rationality based on European and North American cases, and to provide a broader perspective for policy makers to trigger and sustain the development of apprentice-based clusters
    corecore