4,658 research outputs found

    Multi-Objective Optimization of Transonic Compressor Blade Using Evolutionary Algorithm

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77106/1/AIAA-14667-294.pd

    Lamellar carbon nitride membrane for enhanced ion sieving and water desalination

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    Membrane-based water treatment processes offer possibility to alleviate the water scarcity dilemma in energy-efficient and sustainable ways, this has been exemplified in filtration membranes assembled from two-dimensional (2D) materials for water desalination purposes. Most representatives however tend to swell or disintegrate in a hydrated state, making precise ionic or molecular sieving a tough challenge. Here we report that the chemically robust 2D carbon nitride can be activated using aluminum polycations as pillars to modulate the interlayer spacing of the conjugated framework, the noncovalent interaction concomitantly affords a well-interlinked lamellar structure, to be carefully distinguished from random stacking patterns in conventional carbon nitride membranes. The conformally packed membrane is characterized by adaptive subnanochannel and structure integrity to allow excellent swelling resistance, and breaks permeability-selectivity trade-off limit in forward osmosis due to progressively regulated transport passage, achieving high salt rejection (>99.5%) and water flux (6 L m−2h−1), along with tunable permeation behavior that enables water gating in acidic and alkaline environments. These findings position carbon nitride a rising building block to functionally expand the 2D membrane library for applications in water desalination and purification scenarios

    The Invisible Platform of E-Business: Trust

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    E-Business is the new business imperative in the age of Internet. With the features of Internet, business can extend their business activities across space and time. Without traditional fact-to-face interaction, most of the e-business activities can be done through networks. Since they do not have to see each other during e-business transaction, the levels of trust between members are pretty low. Mutual trust within a business, between suppliers and retailers, and between sellers and customers is the most important successful factors of e-business. Based on the review of literatures, we proposed that trust is the most important invisible platform for the e-business. In this article, we discuss the relationship between trust and three major components of e-business: (1) the trust for effective knowledge management (KM) within an organization; (2) the trust between organization and customer for effective customer relationship management (CRM); and (3) the trust between organizations for supply chain management (SCM)

    An ECG-on-Chip with 535-nW/Channel Integrated Lossless Data Compressor for Wireless Sensors

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    This paper presents a low-power ECG recording system-on-chip (SoC) with on-chip low-complexity lossless ECG compression for data reduction in wireless/ambulatory ECG sensor devices. The chip uses a linear slope predictor for data compression, and incorporates a novel low-complexity dynamic coding-packaging scheme to frame the prediction error into fixed-length 16-bit format. The proposed technique achieves an average compression ratio of 2.25x on MIT/BIH ECG database. Implemented in a standard 0.35 um process, the compressor uses 0.565K gates/channel occupying 0.4 mm2 for four channels, and consumes 535 nW/channel at 2.4 V for ECG sampled at 512 Hz. Small size and ultra-low power consumption makes the proposed technique suitable for wearable ECG sensor applications

    Theoretical investigation of structural, energetic and electronic properties of titanate pyrochlores

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    Ab initio total energy calculations using the plane-wave pseudopotential method based on density functional theory were carried out to investigate the structural, energetic and electronic properties of A2Ti2O7 (A =  La, Gd and Yb) pyrochlores. It turned out that the formation energies of antisite defects are not linearly dependent on the ratio of the cation radii, and, for the three compositions, the cation antisite formation energy is largest for Gd2Ti2O7 pyrochlore. It was indicated that Gd2Ti2O7 compound is the least likely to form defect fluorite structure, which gives rise to the least resistance to radiation-induced amorphization. DOS analysis showed that stronger interaction exists in the Gd2Ti2O7 compound, and its electronic structure is very different from that of La2Ti2O7 and Yb2Ti2O7. Our calculations suggested that the electronic structure of the A cation and bond type should be taken into account when explaining the response behavior of A2Ti2O7 (A =  La, Gd, Yb) pyrochlores to ion irradiation-induced amorphization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58124/2/cm7_34_346203.pd
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