2,028 research outputs found

    Single-particle measurements of electrochemical kinetics in NMC and NCA cathodes for Li-ion batteries

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    The electrochemical kinetics of battery electrodes at the single-particle scale are measured as a function of state-of-charge, and interpreted with the aid of concurrent transmission X-ray microscopy (TXM) of the evolving particle microstructure. An electrochemical cell operating with near-picoampere current resolution is used to characterize single secondary particles of two widely-used cathode compounds, NMC333 and NCA. Interfacial charge transfer kinetics are found to vary by two orders of magnitude with state-of-charge (SOC) in both materials, but the origin of the SOC dependence differs greatly. NCA behavior is dominated by electrochemically-induced microfracture, although thin binder coatings significantly ameliorate mechanical degradation, while NMC333 demonstrates strongly increasing interfacial reaction rates with SOC for chemical reasons. Micro-PITT is used to separate interfacial and bulk transport rates, and show that for commercially relevant particle sizes, interfacial transport is rate-limiting at low SOC, while mixed-control dominates at higher SOC. These results provide mechanistic insight into the mesoscale kinetics of ion intercalation compounds, which can guide the development of high performance rechargeable batteries

    Multiagent System for Image Mining

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    The overdone growth, wide availability, and demands for remote sensing databases combined with human limits to analyze such huge datasets lead to a need to investigate tools, techniques, methodologies, and theories capable of assisting humans at extracting knowledge. Image mining arises as a solution to extract implicit knowledge intelligently and semiautomatically or other patterns not explicitly stored in the huge image databases. However, spatial databases are among the ones with the fastest growth due to the volume of spatial information produced many times a day, demanding the investigation of other means for knowledge extraction. Multiagent systems are composed of multiple computing elements known as agents that interact to pursuit their goals. Agents have been used to explore information in the distributed, open, large, and heterogeneous platforms. Agent mining is a potential technology that studies ways of interaction and integration between data mining and agents. This area brought advances to the technologies involved such as theories, methodologies, and solutions to solve relevant issues more precisely, accurately and faster. AgentGeo is evidence of this, a multiagent system of satellite image mining that, promotes advances in the state of the art of agent mining, since it relevant functions to extract knowledge from spatial databases

    A spectral graph theoretic approach to quantification and calibration of collective morphological differences in cell images

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    Motivation: High-throughput image-based assay technologies can rapidly produce a large number of cell images for drug screening, but data analysis is still a major bottleneck that limits their utility. Quantifying a wide variety of morphological differences observed in cell images under different drug influences is still a challenging task because the result can be highly sensitive to sampling and noise

    Czech machinery cluster and its role in sustainable development of Moravian-Silesian enterprises during the post-transformation era

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    The paper intends to contribute to the field of geographical economics by an extensive questionnaire survey carried out in Moravian-Silesian region, which represents one of territories of traditional industry in the Czech Republic. The purpose of this paper is to analyse and assess the co-operation among enterprises, educational institutions, and public administration from the perspective of sustainability in the Moravian-Silesian region during its post-transformation era. The article deals specifically with the Czech machinery cluster. The research question that lies behind the survey is as follows: Is the co-operation of entities present in the Czech machinery cluster beneficial to the parties involved? The contribution of the paper is in uncovering the role of this cluster in the sustainable development of Moravian-Silesian enterprises during post-transformation period. Since the Moravian-Silesian region is a typical old industrial region, which moreover underwent a difficult transformation process, there are numerous peculiarities in functioning of its enterprises. Machinery was traditionally one of the supportive pillars of regional industry and it is not surprising that the machinery cluster was created as the first one. Yet, regional characteristics lie behind specific trajectories towards economic sustainability. The above ways toward economic sustainability differ markedly from the concepts that are in vogue in developed western territories.Web of Science102art. no. 23

    Efficacy of Infection Control Interventions in Reducing the Spread of Multidrug-Resistant Organisms in the Hospital Setting

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    Multidrug-resistant organisms (MDRO) continue to spread in hospitals globally, but the population-level impact of recommended preventive strategies and the relative benefit of individual strategies targeting all MDRO in the hospital setting are unclear. To explore the dynamics of MDRO transmission in the hospital, we develop a model extending data from clinical individual-level studies to quantify the impact of hand hygiene, contact precautions, reducing antimicrobial exposure and screening surveillance cultures in decreasing the prevalence of MDRO colonization and infection. The effect of an ongoing increase in the influx of patients colonized with MDRO into the hospital setting is also quantified. We find that most recommended strategies have substantial effect in decreasing the prevalence of MDRO over time. However, screening for asymptomatic MDRO colonization among patients who are not receiving antimicrobials is of minimal value in reducing the spread of MDRO
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