2,298 research outputs found

    Thermophysical and elastic properties of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass-forming alloys

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    By employing a containerless high-temperature high-vacuum electrostatic levitation technique, the thermophysical properties, including the ratio between the specific heat capacity and the hemispherical total emissivity, the specific volume, and the viscosity, of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass (BMG)-forming liquids have been measured. Compared with Cu50Zr50, the improved glass-forming ability of (Cu50Zr50)95Al5 can be attributed to its dense liquid structure and its high value of viscosity. Additionally, the relationship between the viscosity of various BMG forming liquids at the melting temperature and the elastic properties of the corresponding glasses at room temperature will be compared

    Laser-based three-dimensional manufacturing technologies for rechargeable batteries.

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    Laser three-dimensional (3D) manufacturing technologies have gained substantial attention to fabricate 3D structured electrochemical rechargeable batteries. Laser 3D manufacturing techniques offer excellent 3D microstructure controllability, good design flexibility, process simplicity, and high energy and cost efficiencies, which are beneficial for rechargeable battery cell manufacturing. In this review, notable progress in development of the rechargeable battery cells via laser 3D manufacturing techniques is introduced and discussed. The basic concepts and remarkable achievements of four representative laser 3D manufacturing techniques such as selective laser sintering (or melting) techniques, direct laser writing for graphene-based electrodes, laser-induced forward transfer technique and laser ablation subtractive manufacturing are highlighted. Finally, major challenges and prospects of the laser 3D manufacturing technologies for battery cell manufacturing will be provided

    Dynamics of axial separation in long rotating drums

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    We propose a continuum description for the axial separation of granular materials in a long rotating drum. The model, operating with two local variables, concentration difference and the dynamic angle of repose, describes both initial transient traveling wave dynamics and long-term segregation of the binary mixture. Segregation proceeds through ultra-slow logarithmic coarsening.Comment: 4 pages, 3 Postscript figures; submitted to PR

    Fuzzy identity-based data integrity auditing for reliable cloud storage systems

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.As a core security issue in reliable cloud storage, data integrity has received much attention. Data auditing protocols enable a verifier to efficiently check the integrity of the outsourced data without downloading the data. A key research challenge associated with existing designs of data auditing protocols is the complexity in key management. In this paper, we seek to address the complex key management challenge in cloud data integrity checking by introducing fuzzy identity-based auditing-the first in such an approach, to the best of our knowledge. More specifically, we present the primitive of fuzzy identity-based data auditing, where a user’s identity can be viewed as a set of descriptive attributes. We formalize the system model and the security model for this new primitive. We then present a concrete construction of fuzzy identity-based auditing protocol by utilizing biometrics as the fuzzy identity. The new protocol offers the property of error-tolerance, namely, it binds private key to one identity which can be used to verify the correctness of a response generated with another identity, if and only if both identities are sufficiently close. We prove the security of our protocol based on the computational Diffie-Hellman assumption and the discrete logarithm assumption in the selective-ID security model. Finally, we develop a prototype implementation of the protocol which demonstrates the practicality of the proposal.This work is supported by the National Natural Science Foundation of China (61501333,61300213,61272436,61472083), the Fundamental Research Funds for the Central Universities under Grant ZYGX2015J05

    Chemically Cross-Linked Graphene Oxide as a Selective Layer on Electrospun Polyvinyl Alcohol Nanofiber Membrane for Nanofiltration Application.

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    Graphene oxide (GO) nanosheets were utilized as a selective layer on a highly porous polyvinyl alcohol (PVA) nanofiber support via a pressure-assisted self-assembly technique to synthesize composite nanofiltration membranes. The GO layer was rendered stable by cross-linking the nanosheets (GO-to-GO) and by linking them onto the support surface (GO-to-PVA) using glutaraldehyde (GA). The amounts of GO and GA deposited on the PVA substrate were varied to determine the optimum nanofiltration membrane both in terms of water flux and salt rejection performances. The successful GA cross-linking of GO interlayers and GO-PVA via acetalization was confirmed by FTIR and XPS analyses, which corroborated with other characterization results from contact angle and zeta potential measurements. Morphologies of the most effective membrane (CGOPVA-50) featured a defect-free GA cross-linked GO layer with a thickness of ~67 nm. The best solute rejections of the CGOPVA-50 membrane were 91.01% for Na2SO4 (20 mM), 98.12% for Eosin Y (10 mg/L), 76.92% for Methylene blue (10 mg/L), and 49.62% for NaCl (20 mM). These findings may provide one of the promising approaches in synthesizing mechanically stable GO-based thin-film composite membranes that are effective for solute separation via nanofiltration

    LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation

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    Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack)

    Traveling Granular Segregation Patterns in a Long Drum Mixer

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    Mixtures of granular media often exhibit size segregation along the axis of a partially-filled, horizontal, rotating cylinder. Previous experiments have observed axial bands of segregation that grow from concentration fluctuations and merge in a manner analogous to spinodal decomposition. We have observed that a new dynamical state precedes this effect in certain mixtures: bi-directional traveling waves. By preparing initial conditions, we found that the wave speed decreased with wavelength. Such waves appear to be inconsistent with simple PDE models which are first order in time.Comment: 11 page

    Effects of Escherichia coli vaccination in gilts on piglet performance in a farm in Perak

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    This study aimed to observe the effects of Escherichia coli (Neocoliporvaccine – Merial) vaccination on diarrhoea percentages, growth parameters (average weight per piglet and average daily gain) and mortality rate in new-born piglets. A field trial was conducted in 35 litters of piglets from gilts selected from a farm in Perak. They were randomly allocated into Treatment (16 litters from E. coli vaccinated gilts) and Control (19 litters) groups respectively. Body weights of the piglets were measured at days 1, 7, 14 and 21 of age and the episodes of diarrhoea and piglet mortality were monitored daily for each pen. The Treatment group had significantly lower Day 1 neonatal diarrhoea percentage (p 0.05)in the overall diarrhoea percentages (1 - 14 days) and weekly growth parameters between both groups. Environmental stress and inevitable routine treatment of diarrhoea with antimicrobials within the farm may have affected the significance of the diarrhoea percentages and growth parameters in this study. In conclusion, E. coli vaccination in gilts was shown to significantly reduce piglet mortality from Day 1 to Day 7 and neonatal diarrhoeal percentageson1-day-old piglets under typical farm conditions in this pilot study in Malaysia
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