935 research outputs found

    Overall Performance Evaluation of Tubular Scraper Conveyors Using a TOPSIS-Based Multiattribute Decision-Making Method

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    Properly evaluating the overall performance of tubular scraper conveyors (TSCs) can increase their overall efficiency and reduce economic investments, but such methods have rarely been studied. This study evaluated the overall performance of TSCs based on the technique for order of preference by similarity to ideal solution (TOPSIS). Three conveyors of the same type produced in the same factory were investigated. Their scraper space, material filling coefficient, and vibration coefficient of the traction components were evaluated. A mathematical model of the multiattribute decision matrix was constructed; a weighted judgment matrix was obtained using the DELPHI method. The linguistic positive-ideal solution (LPIS), the linguistic negative-ideal solution (LNIS), and the distance from each solution to the LPIS and the LNIS, that is, the approximation degrees, were calculated. The optimal solution was determined by ordering the approximation degrees for each solution. The TOPSIS-based results were compared with the measurement results provided by the manufacturer. The ordering result based on the three evaluated parameters was highly consistent with the result provided by the manufacturer. The TOPSIS-based method serves as a suitable evaluation tool for the overall performance of TSCs. It facilitates the optimal deployment of TSCs for industrial purposes

    Study Horizontal Screw Conveyors Efficiency Flat Bottomed Bins EDEM Simulation

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    It describes the development history flat bottom silo, characteristics and testing system, composition. For the poor current theory and computer simulation study on horizontal spiral conveyor in the system, Using Solidworks to establish a reasonable three-dimensional model of flat bottom silo Horizontal Screw Conveyors, to import the model into EDEM software, simulation. By setting parameters and the model material parameters, draw motion vectors of the material along the helical axis, horizontal screw conveyor average number of transported materials particles, The results with experimental results compared to abroad, Flat bottom silo systems used EDEM software for the efficiency study of horizontal screw conveyors is authenticity and reliability, at the same time, the simulation makes the screw conveyor filling rate to identify more specific , Save time on flat bottom bunker system design, shorten the development cycle

    Idle Time Optimization for Target Assignment and Path Finding in Sortation Centers

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    In this paper, we study the one-shot and lifelong versions of the Target Assignment and Path Finding problem in automated sortation centers, where each agent needs to constantly assign itself a sorting station, move to its assigned station without colliding with obstacles or other agents, wait in the queue of that station to obtain a parcel for delivery, and then deliver the parcel to a sorting bin. The throughput of such centers is largely determined by the total idle time of all stations since their queues can frequently become empty. To address this problem, we first formalize and study the one-shot version that assigns stations to a set of agents and finds collision-free paths for the agents to their assigned stations. We present efficient algorithms for this task based on a novel min-cost max-flow formulation that minimizes the total idle time of all stations in a fixed time window. We then demonstrate how our algorithms for solving the one-shot problem can be applied to solving the lifelong problem as well. Experimentally, we believe to be the first researchers to consider real-world automated sortation centers using an industrial simulator with realistic data and a kinodynamic model of real robots. On this simulator, we showcase the benefits of our algorithms by demonstrating their efficiency and effectiveness for up to 350 agents.Comment: AAAI 2020, to appea

    Dichlorido(2,9-dimeth­oxy-1,10-phenanthroline-Îș2 N,Nâ€Č)zinc(II)

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    In the crystal structure of the title compound, [ZnCl2(C14H12N2O2)], the ZnII center is four-coordinated by two N atoms from one 2,9-dimeth­oxy-1,10-phenanthroline ligand and two Cl atoms. The coordination geometry is distorted tetra­hedral, as the Zn—N bond distances are shorter than the Zn—Cl distances, and the Cl—Zn—N and Cl—Zn—Cl bond angles are much larger than the N—Zn—N angle. For the ligand, the O and C atoms of the meth­oxy groups are almost in the plane defined by the phenanthroline ring. The two O atoms deviate from the phenanthroline mean plane by 0.076 (2) and 0.084 (2) Å, and the two methyl C atoms deviate from the phenanthroline mean plane by 0.035 (3) and 0.361 (3) Å. There are medium π–π stacking interactions between two parallel phenanthroline rings with a centroid–centroid distance of 3.7860 (2) Å and a dihedral angle between the plane defined by the two parallel phenanthroline rings of 1.13 (5)°

    Study of Three Rotating Radio Transients with FAST

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    Rotating radio transients (RRATs) are peculiar astronomical objects whose emission mechanism remains under investigation. In this paper, we present observations of three RRATs, J1538+2345, J1854+0306 and J1913+1330, observed with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Specifically, we analyze the mean pulse profiles and temporal flux density evolutions of the RRATs. Owing to the high sensitivity of FAST, the derived burst rates of the three RRATs are higher than those in previous reports. RRAT J1854+0306 exhibited a time-dynamic mean pulse profile, whereas RRAT J1913+1330 showed distinct radiation and nulling segments on its pulse intensity trains. The mean pulse profile variation with frequency is also studied for RRAT J1538+2345 and RRAT J1913+1330, and the profiles at different frequencies could be well fitted with a cone-core model and a conal-beam model, respectively.Comment: Sci. China-Phys. Mech. Astron. 62, 959503 (2019

    Estradiol Promotes M1-like Macrophage Activation through Cadherin-11 To Aggravate Temporomandibular Joint Inflammation in Rats

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    Macrophages play a major role in joint inflammation. Estrogen is involved in rheumatoid arthritis and temporomandibular disorders. However, the underlying mechanism is still unclear. This study was done to verify and test how estrogen affects M1/M2-like macrophage polarization and then contributes to joint inflammation. Female rats were ovariectomized and treated with increasing doses of 17ÎČ-estradiol for 10 d and then intra-articularly injected with CFA to induce temporomandibular joint (TMJ) inflammation. The polarization of macrophages and expression of cadherin-11 was evaluated at 24 h after the induction of TMJ inflammation and after blocking cadherin-11 or estrogen receptors. NR8383 macrophages were treated with estradiol and TNF-α, with or without blocking cadherin-11 or estrogen receptors, to evaluate the expression of the M1/M2-like macrophageassociated genes. We found that estradiol increased the infiltration of macrophages with a proinflammatory M1-like predominant profile in the synovium of inflamed TMJ. In addition, estradiol dose-dependently upregulated the expressions of the M1-associated proinflammatory factor inducible NO synthase (iNOS) but repressed the expressions of the M2-associated genes IL-10 and arginase in NR8383 macrophages. Furthermore, estradiol mainly promoted cadherin-11 expression in M1-like macrophages of inflamed TMJ. By contrast, blockage of cadherin-11 concurrently reversed estradiol-potentiated M1-like macrophage activation and TMJ inflammation, as well as reversed TNF-α-induced induction of inducible NO synthase and NO in NR8383 macrophages. The blocking of estrogen receptors reversed estradiol-potentiated M1-like macrophage activation and cadherin-11 expression. These results suggested that estradiol could promote M1-like macrophage activation through cadherin-11 to aggravate the acute inflammation of TMJs. Copyright © 2015 by The American Association of Immunologists, Inc
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