We consider the stochastic queue core problem on a tree network. Our aim is to find an optimal path on a tree network subject to the average travel time of particles moving along the tree for service given by a server...
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We consider the stochastic queue core problem on a tree network. Our aim is to find an optimal path on a tree network subject to the average travel time of particles moving along the tree for service given by a server traversing along the optimal path. We assume that particles originating at a node on a tree network request their demands for service randomly and the server is modeled first by an M/M/1 and then by an M/G/1 queue using the FIFO discipline. We consider that all paths along which the particles travel are modeled with an M/G/c/c state-dependent queue with the particles being independent of each other having demands according to the Poisson distribution. Two algorithms are developed for computing the optimal path on a tree network along with the M/M/1 and the M/G/1 queues. The computational complexity of the algorithms and illustrative numerical results obtained by implementations of the algorithms in MATLAB software environment are given.
Fullerene based electronic devices are gathering much attention due to their excellent properties. Among many of the carbon fullerenes available, ‘c 20 ′ is so far the smallest fullerene of carbon. c 20 structure is...
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Fullerene based electronic devices are gathering much attention due to their excellent properties. Among many of the carbon fullerenes available, ‘c 20 ′ is so far the smallest fullerene of carbon. c 20 structure is like a polyhedral cage having 30 edges with zero (n-2/10) hexagons and twelve pentagons. It is the only known fullerene smaller than c 60 with full Ih symmetry. Even though it is a small molecule it has extraordinary properties which make it fit for usage in various applications as it has NDR behavior, it can bind with proteins and most importantly is coherent and reliable. It is utilized in applications like organic solar cells, creation of hybrid materials and in various sensing applications. Although a lot of research is ongoing on c 20 , yet further research is required to get more insights into its properties. Therefore, this paper contains detailed review on c 20 fullerene and future research prospects.
A subgroup H of a group G is called an ℋ c -subgroup of G if there exists a normal subgroup T of G such that G = H T and H g ∩ N T ( H ) ≤ H for all g ∈ G . In this paper, we obtain new criteria for a normal subgro...
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A subgroup H of a group G is called an ℋ c -subgroup of G if there exists a normal subgroup T of G such that G = H T and H g ∩ N T ( H ) ≤ H for all g ∈ G . In this paper, we obtain new criteria for a normal subgroup to be contained in the p 𝔉 -hypercenter of a finite group by assuming that some of its subgroups are ℋ c -subgroups. Our results generalize and uniform many known results.
Aluminium alloy 6063-T6 is a popular choice among different industrial sectors as it portrays various desirable properties like moderate strength, improved corrosion resistance, better weldability and formability etc....
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Aluminium alloy 6063-T6 is a popular choice among different industrial sectors as it portrays various desirable properties like moderate strength, improved corrosion resistance, better weldability and formability etc. These advantages make AA6063-T6 a common choice for matrix in a metal matrix composite. Mostly conventional fusion welding methods like Metal Inert Gas (MIG) and Tungsten Inert Gas (TIG) seem preferable options for welding aluminium and its alloys but it remains a challenge to use them to weld aluminium metal matrix composite. A modified version of MIG i.e. cMT welding, can be explored to overcome the challenges. In this study, an aluminium metal matrix composite has been fabricated with AA6063-T6 as matrix and two reinforcements −one organic, i.e., Eggshell (ES) and one inorganic, i.e., Boron carbide (B 4 c), using the conventional stir casting method. cMT welding has been performed on plates cut out from the composites. Microstructure, hardness, tensile strength and residual stress of weld joint of composite have been observed. From micrographs, it is observed that a finer grain has been formed at the Fusion Zone (FZ) in comparison to the Heat Affected Zone (HAZ) and Parent Material (PM). XRD analysis at the fusion line has identified several intermetallic stoichiometriccompounds (Al 12 Mg 17 , Mg 2 Si, caMgSi, caO, B 2 O 3 ) and reinforcement B 4 c and cacO 3 within the matrix volume. The FZ exhibits higher hardness than the HAZ and the PM. Further, the tensile strength of the FZ exceeds that of the unwelded composite due to the presence of metastable strengthening phases of Mg 2 Si in the FZ, along with reinforcement (B 4 c and ES) particles. Residual stress analysis reveals tensile stress in the FZ and more compressive stress in the HAZ than in the PM.
A series of LiFePO4/ccomposites are prepared under the conditions of pH = 3, 5, 7, 8, 9 via biosynthesis method. The X-ray diffraction demonstrates that all of well-crystallized LiFePO4/ccomposites can be successful...
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A series of LiFePO4/ccomposites are prepared under the conditions of pH = 3, 5, 7, 8, 9 via biosynthesis method. The X-ray diffraction demonstrates that all of well-crystallized LiFePO4/ccomposites can be successfully prepared by adjusting the pH value. The images of scanning electron microscopy show that the structure and size of different samples have obvious changes. Besides, the LiFePO4/ccomposite prepared at the value of 8 delivers a best discharge capacity of 158.7 mAh/g at 0.1 c. The results show that the electrochemical performance of LiFePO4/ccomposites is governed by pH value.
Bicyclol is a synthetic drug for hepatoprotection in clinic since 2004. Preliminary clinical observations suggest that bicyclol might be active against hepatitis c virus(HcV) with unknown mechanism. Here, we showed th...
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Bicyclol is a synthetic drug for hepatoprotection in clinic since 2004. Preliminary clinical observations suggest that bicyclol might be active against hepatitis c virus(HcV) with unknown mechanism. Here, we showed that bicyclol significantly inhibited HcV replication in vitro and in hepatitis c patients. Using bicyclol as a probe, we identified glycolipid transfer protein(GLTP) to be a novel restrictive factor for HcV replication. The GLTP preferentially bound host vesicle-associated membrane protein-associated protein-A(VAP-A) in competition with the HcV NS5 A, causing an interruption of the complex formation between VAP-A and HcV NS5 A. As the formation of VAP-A/NS5 A complex is essential for viral RNA replication, up-regulation of GLTP by bicyclol reduced the level of VAP-A/NS5 A complex and thus inhibited HcV replication. Bicyclol also exhibited an inhibition on HcV variants resistant to direct-acting antiviral agents(DAAs) with an efficacy identical to that on wild type HcV. In combination with bicyclol, DAAs inhibited HcV replication in a synergistic fashion. GLTP appears to be a newly discovered host restrictive factor for HcV replication, Up-regulation of GLTP causes spontaneous restriction of HcV replication.
In this paper, a high-temperature test experimental system is built to investigate the dependence of the strength of a c/Siccomposite material on temperature. Unintuitively, the strength increases with temperature. T...
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In this paper, a high-temperature test experimental system is built to investigate the dependence of the strength of a c/Siccomposite material on temperature. Unintuitively, the strength increases with temperature. To investigate the microscopic mechanism, scanning electron microscopy (SEM) of an in situ bending test experiment is performed. Our hypothesis is that due to significant residual tensile stress in inter-fibre matrix, external loads reach the ultimate stress first. As the temperature increases, the matrix residual tensile stress decreases, a larger external load needs to be applied for matrix failure, which is exhibited macroscopically as increased strength. To prove this hypothesis, the inter-fibre matrix residual stress and its dependence on temperature are calculated via a finite element method. Next, using a Sic wrapper layer around a single c fibre as an experiment object, the finite element calculation is verified directly via micro-Raman spectroscopy.
A LiFePO4/c material with different amounts of iron phosphides was synthesized by a sol-gel method with different calcination temperatures. XRD, HRTEM, SEM, FTIR, BET, Raman, and magnetic measurements were carried out...
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A LiFePO4/c material with different amounts of iron phosphides was synthesized by a sol-gel method with different calcination temperatures. XRD, HRTEM, SEM, FTIR, BET, Raman, and magnetic measurements were carried out to characterize the physical properties of the LiFePO4/c, while EIS, cV, and charge-discharge tests were carried out to characterize the electrochemical performance. It is obtained that the crystallinity, the particle size of the LiFePO4, and the amount of iron phosphides in the sample are the factors that affect the electrochemical performance of the material, where the key factor determining the electrochemical performance varies in different situations. The samples possessing well-crystallized LiFePO4 particles and similar particle size demonstrated improved rate performance with the increasing amount of iron phosphides when the calcination temperature increased from 650 to 750 degrees c. The results showed that the rate performance could be improved by harmonious improvement of the ionicconductivity of Li+ and the electronicconductivity.
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