657 research outputs found

    A hybrid performance evaluation approach for urban logistics using extended cross-efficiency with prospect theory and OWA operator

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    Urban logistics performance evaluation can provide reference for further improving its level. However, most performance evaluation for urban logistics premises that decision-makers (DMs) are completely rational, which may not conform to the actual situation. Therefore, this article aims to consider the DMs’ psychological factors in the performance evaluation of urban logistics. Specifically, the cross-efficiency evaluation (CEE) method with the DMs’ psychological factors is used to measure the urban logistics efficiency in the central area of Yangtze River Delta (YRD) urban agglomeration in China in 2019. The main contributions in this article are to propose a hybrid CEE method with prospect theory and ordered weighted average (OWA) operator for urban logistics industry and to expand the evaluation perspectives of urban logistics performance. The main conclusions are obtained: (1) The DMs’ optimism level can indeed affect the efficiency value and ranking of urban logistics. (2) The aggregation based on the OWA operator is fair and reasonable because it can make all self-evaluation efficiencies play the same role. (3) To make the efficiencies and rankings of urban logistics in the central area of the YRD have credibility and discrimination, the DMs’ optimism level range is best between 0.8 and 0.8177

    Effect of size and processing method on the cytotoxicity of realgar nanoparticles in cancer cell lines

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    In this study, the effects of the size and Chinese traditional processing (including elutriation, water cleaning, acid cleaning, alkali cleaning) on realgar nanoparticles (RN)-induced antitumor activity in human osteosarcoma cell lines (MG-63) and hepatoma carcinoma cell lines (HepG-2) were investigated. The human normal liver cell line (L-02) was used as control. RN was prepared by high-energy ball milling technology. The results showed that with the assistance of sodium dodecyl sulfate, the size of realgar could be reduced to 127 nm after 12 hours’ ball milling. The surface charge was decreased from 0.83 eV to −17.85 eV and the content of As2O3 clearly increased. Except for elutriation, the processing methods did not clearly change the size of the RN, but the content of As2O3 was reduced dramatically. In vitro MTT tests indicated that in the two cancer cell lines, RN cytotoxicity was more intense than that of the coarse realgar nanoparticles, and cytotoxicity was typically time- and concentration-dependent. Also, RN cytotoxicities in the HepG-2 and L-02 cells all increased with increasing milling time. Due to the reduction of the As2O3 content, water cleaning, acid cleaning, and alkali cleaning decreased RN cytotoxicity in HepG-2, but RN after elutriation, with the lowest As2O3 (3.5 mg/g) and the smallest size (109.3 nm), showed comparable cytotoxicity in HepG-2 to RN without treatment. Meanwhile, RN-induced cytotoxicity in L-02 cells was clearly reduced. Therefore, it can be concluded that RN may provide a strong antiproliferation effect in the MG-63 and HepG-2 cells. Elutriation processing is a suitable approach to limit the dangerous side-effects of As2O3, while maintaining the effectiveness of RN

    Experimental Study of Ultralight (<300 kg/m 3

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    A type of ultralight (<300 kg/m3) foamed concrete (FC), which can be used as a new energy-conservation and environmental-protection building material and is particularly suitable for the thermal-insulation engineering of building external walls, was produced. The influences of different mixing amounts of fly ash, fly ash activator, WC (WC) ratio, and foaming agent (FA) on the compressive strength of FC were reported. The experimental study indicated that (1) the addition of fly ash reduced the strength of the FC and that the appropriate mixing amount of fly ash in this ultralight FC system should not exceed 45%; (2) with the increasing of fly ash activator, the strength of the FC sample is notably enhanced and the appropriate mixing amount of fly ash activator is 2.5%; (3) the optimized proportion of WC ratio is 0.45, and the FC that was produced according to this proportion has relatively high compressive strength; (4) by increasing the mixing amount of FA, the compressive strength of the FC notably decreases, and the optimal mixing amount of FA in this experiment is 3.5%

    Investigation of Magnetic Nanoparticle Motion under a Gradient Magnetic Field by an Electromagnet

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    Finite element numerical simulations were carried out in 2D geometry to calculate the magnetic force on magnetic nanoparticles under a specially fabricated electromagnet. The particle motion was modeled by a system of ordinary differential equations. The snapshots of trajectories of 4000 MNPs with and without magnetic field were analyzed and qualitatively found to be in agreement with camera visualizations of MNP movement in a container. The results of the analysis could be helpful for the design of electromagnetic field and motion analysis of magnetic particles for the delivery of magnetic materials in biomedical applications

    Putting Structure into Fluidized Bed – From Concept to Industrial Applications

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    Structures of particles, particle agglomerates, distributors, and internals have significantly influence on hydrodynamics and transfer behaviors of the dense gas-solid fluidized bed. For nanomaterial production, the particle surface and their agglomerated structures directly influence the fluidization behaviors; while for coal to chemical process, the distributors, internals play an important role in regime transient, and hydrodynamics. Carbon nanotubes mass production, coal to chemicals process. and fuel production were employed as examples to describe the concept of putting structures into fluidized bed, and then to put these structures into industrial applications
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