A 2-pile take-away game is played by two players who alternate in removing tokens from two piles according to given rules. The game is invariant if if the same moves can be played from any game position, provided only that there are enough tokens in the piles. Duchêne and Rigo in a paper in this issue conjectured that if the second player winning positions are given by a pair of complementary h...

Received: June 12, 2017 Revised: October 24, 2017 Accepted: November 03, 2017 Abstract: Background and Objective: Prestressed high strength concrete pipe pile (PHC) shows brittle fracture when subjected to more than its own bearing capacity. Therefore, the non-prestressed steel bar is added to the PHC pipe pile, that is, the mixed reinforced pipe pile (PRC). The mechanical behavior of PRC group...

membrane technology is used to separate water or solvents from salts or pollutants. this technique could be used for water treatment. for using of polyether sulfone (pes) hollow fiber membranes in water treatment processes, the pes hollow fiber membranes were prepared by dry-wet spinning method and heated in an oven at: 120°c, 150°c and 180°c. the effect of heating on performance of membranes w...

Abstract Steel sheet pile walls are being widely used in civil engineering projects for support systems. Soil is not uniform in depth, sometimes may be exit loose or soft soil layer in various depth. This issue can cause different effects on ground surface displacements, forces and moments acting on sheet piles and struts during excavation procedure, compared with status that soil is uniform...

NiS2 hollow spheres are successfully prepared by a one-step template free method. Meanwhile, α-NiS hollow spheres can also be synthesized via the calcination of the pre-obtained NiS2 hollow spheres at 400 °C for 1 h in air. The electrochemical performances of the as-prepared NiS2 and α-NiS hollow sphere products are evaluated. When used for supercapacitors, compared with NiS2 hollow spheres, th...

ZnO-SnO2 hollow spheres were successfully synthesized through a hydrothermal method-combined carbon sphere template. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). The average diameter of hollow spheres is about 150 nm. The photocatalytic activity of the a...

In this study, a topotactic transformation route was proposed to synthesize single-crystalline β-NiS hollow spheres with uniform phase and morphology evolving from polycrystalline α-NiS hollow spheres. Uniform polycrystalline α-NiS hollow spheres were firstly prepared with thiourea and glutathione as sulfur sources under hydrothermal conditions through the Kirkendall effect. By increasing the r...

Hollow-sapphire and metal-dielectric-coated hollow-glass waveguides have been used to deliver CO(2) laser power for industrial laser applications. The transmission, bending loss, and output-beam properties of these waveguides are described. The bore sizes of the hollow-sapphire waveguides were 1070 and 790 μm, and the hollow-glass waveguide had a bore of 700 μm. The waveguides ranged in length ...

Uniform hollow spheres of Cu2O and CuS were successfully synthesized by chemical transformation of in situ formed sacrificial templates containing Cu(I) in aqueous solutions. The shell thickness of these hollow spheres can be adjusted through the choice of the bromide source used for the formation of intermediate templates. Specifically, thick-shell hollow spheres (about 130-180 nm in shell thi...