370 research outputs found

    Fast battery-charging architecture

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    The disclosure describes a power-efficient, low-footprint, and fast battery charger based on a hybrid of the charge pump and the three-level chargers. The charger is low cost, reduces thermal dissipation, increases battery-charging speed, and is compatible with wired and wireless charging

    Investigation of the interactions between titanium and calcium zirconium oxide (CaZrO3) ceramics modified with alumina

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    Powdered mixtures of CaO, ZrO2 and Al2O3 in various ratios were hot pressed. The mixtures reacted with titanium at 1600 °C for 30 min in argon to evaluate the suitable ceramic crucibles for casting of titanium. The interfacial microstructures between titanium and ceramic composites were characterized using X-ray diffractometer, scanning and transmission electron microscope. The produced hot pressed mixtures that were chemically bonded together, contained calcium aluminate (CaAl2O4), calcium dialuminate (CaAl4O7), cubic zirconia (c-ZrO2), and calcium zirconium oxide (CaZrO3). The increase in Al2O3 amount led to the decrease in CaZrO3 amount and an increase in the amount of CaAl2O4, CaAl4O7 and c-ZrO2 due to the reaction of CaO and Al2O3. At the end of the reaction of the ceramic mixtures with Ti at 1600 °C for 30 min, the acicular α-Ti and β′-Ti were formed at the interface of Ti and the composites containing up to 10 vol.% Al2O3. In composites containing more than 20 vol.% Al2O3, Ti3Al5 was found at the interface instead of α-Ti and β′-Ti. Furthermore, CaZrO3, ZrO2 and Ca3Al2O6 existed on the sides of the ceramic far away from the interface. CaZrO3/Al2O3 composites with less than 20 vol.% Al2O3 could be a potential crucible or mould material for productive applications in titanium casting

    Modeling Medical Summary Sharing Service with Web Services

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    Enterprises are entering a new Internet era. The Web, initially designed for human use, will now evolve to better support automated use. In this new era, enterprises will have the capability to assemble large-scale systems out of network-bound software components within the reach of mass-market consumers. This study aims to depict the conversations between business processes and Web service technologies, explain what and how can Web services support message sharing between business partners. A Medical Summary Sharing process from IHE is implemented with Web services technologies in a Long-Term Care Management Center setting. In this scenario, one manager in Care Management Center uses a care plan creation application to evaluate care requirements for one patient. The conversations between the application and Web services are explained using Web Service Business Process Execution Language (WS-BPEL) in business process side and Web Services Description Language (WSDL) in technical side. We discovered that basic Web service technologies have matured enough to support enterprises in composition of Web services and further research should be made to identify novelty in using the technologies and to ensure operational quality while the services are consumed

    A rare, highly aggressive primitive neuroectodermal tumor of the kidney: Case report and literature review

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    AbstractWe report a case of a 14-year-old boy who initially suffered from a sudden onset of abdominal pain for 2 weeks with a protrusive soft mass over the left upper abdomen. No obvious symptomatic symptoms or body weight loss were observed. However, early lung metastasis was detected after an initial computed tomographic examination. Even after we performed salvage en bloc resection of the huge retroperitoneal tumor after primary neoadjuvant chemotherapy, the final outcome was still poor. A diagnosis according to radiologic findings was uncharacteristic. Finally, a pathologic diagnosis based on histologic and immunohistochemical results revealed a rare renal peripheral primitive neuroectodermal tumor

    PEDOT:PSS/Graphene Nanocomposite Hole-Injection Layer in Polymer Light-Emitting Diodes

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    We report on effects of doping graphene in poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate), PEDOT:PSS, as a PEDOT:PSS/graphene nanocomposite hole injection layer on the performance enhancement of polymer light-emitting diodes (PLEDs). Graphene oxides were first synthesized and then mixed in the PEDOT:PSS solution with specifically various amounts. Graphenes were reduced in the PEDOT:PSS matrix through thermal reduction. PLED devices with hole-injection nanocomposite layer containing particular doping concentration were fabricated, and the influence of doping concentration on device performance was examined by systematically characterizations of various device properties. Through the graphene doping, the resistance in the hole-injection layer and the turn-on voltage could be effectively reduced that benefited the injection and transport of holes and resulted in a higher overall efficiency. The conductivity of the hole-injection layer was monotonically increased with the increase of doping concentration, performance indices from various aspects, however, did not show the same dependence because faster injected holes might alter not only the balance of holes and electrons but also their combination locations in the light-emitting layer. Results show that optimal doping concentration was the case with 0.03 wt% of graphene oxide

    ATP Released by Astrocytes Mediates Glutamatergic Activity-Dependent Heterosynaptic Suppression

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    AbstractExtracellular ATP released from axons is known to assist activity-dependent signaling between neurons and Schwann cells in the peripheral nervous system. Here we report that ATP released from astrocytes as a result of neuronal activity can also modulate central synaptic transmission. In cultures of hippocampal neurons, endogenously released ATP tonically suppresses glutamatergic synapses via presynaptic P2Y receptors, an effect that depends on the presence of cocultured astrocytes. Glutamate release accompanying neuronal activity also activates non-NMDA receptors of nearby astrocytes and triggers ATP release from these cells, which in turn causes homo- and heterosynaptic suppression. In CA1 pyramidal neurons of hippocampal slices, a similar synaptic suppression was also produced by adenosine, an immediate degradation product of ATP released by glial cells. Thus, neuron-glia crosstalk may participate in activity-dependent synaptic modulation

    Experimental Investigation on Thermoelectric Chiller Driven by Solar Cell

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    This paper presents experimental explorations on cooling performance of thermoelectric chillers being driven by solar cells, as well as comparison results to the performance being driven by fixed direct current. Solar energy is clear and limitless and can be collected by solar cells. We use solar cells to drive thermoelectric chillers, where the cold side is connected to the water tank. It is found that 250 mL of water can be cooled from 18.5°C to 13°C, where the corresponding coefficient of performance (COP) is changed between 0.55 and 1.05, when solar insolation is changed between 450 W/m2 and 1000 W/m2. The experimental results demonstrate that the thermoelectric chiller driven by solar cell is feasible and effective for energy saving issues
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