The forces between a flat gold surface and a gold-coated silica sphere have been measured in water using an atomic force microscope. A long-range attractive interaction is observed which is ascribed to the van der Waals interaction between the two surfaces. The force data agree extremely well with recent, calculated values of the Hamaker function (including retardation) for gold/water/gold. The...

production and preparation of many parts of the aircraft body including wings with long length, smooth form, and large radius of curvature are amongst the most important challenges in this industry. in this paper, the effective factors in the rubber pad forming method on a pieces contain curvature radius have been investigated by finite element method. the effect of variables such as curvature ...

The list decoding problem for a code asks for the maximal radius up to which any ball of that radius contains only a constant number of codewords. The list decoding radius is not well understood even for well studied codes, like Reed-Solomon or Reed-Muller codes. Fix a finite field F. The Reed-Muller code RMF(n, d) is defined by n-variate degree-d polynomials over F. In this work, we study the ...

We consider a wireless sensor network in which each sensor is able to transmit within a disk of radius one. We show with elementary techniques that there exists a constant c such that if we throw cN sensors into an n × n square (of area N) independently at random, then with high probability there will be exactly one connected component which reaches all sides of the square. Its expected size is...

Let X be a compact Riemann surface of genus ≥ 2 of constant negative curvature −1. An extremal disk is an embedded (resp. covering) disk of maximal (resp. minimal) radius. A surface containing an extremal disk is an extremal surface. This paper gives formulas enumerating extremal surfaces of genus ≥ 4 up to isometry. We show also that the isometry group of an extremal surface is always cyclic o...

We provide the modified TOV equations for hydrostatic equilibrium of charged compact stars within metric $f(R)$ gravitational background. adopt MIT bag model EoS dense matter and assume a charge distribution where electric density $\rho_{\rm ch}$ is proportional to standard energy $\rho$. Using Starobinsky model, we explore role $\alpha R^2$ term, $\alpha$ free constant $R$ Ricci scalar, on glo...

The Hubble constant, which measures the expansion rate, together with the total energy density of the Universe, sets the size of the observable Universe, its age, and its radius of curvature. Excellent progress has been made recently toward the measurement of the Hubble constant: a number of different methods for measuring distances have been developed and refined, and a primary project of the ...

Although the evaporation mode of sessile droplets is almost universally characterized as either constant contact radius (CCR) or constant contact angle (CCA), here we investigate two alternatives where the contact line speed is either constant or inversely proportional to the droplet radius. We present supporting evidence from our experiments on poly(ethylene oxide) (PEO) polymer solutions and ...

Within the framework of [Formula: see text] theories gravity, we investigate hydrostatic equilibrium anisotropic neutron stars with a physically relevant equation state (EoS) for radial pressure. In particular, focus on model, where is minimal coupling constant. slowly rotating approximation, derive modified TOV equations and expression relativistic moment inertia. The main properties stars, su...

in this research, the effect of the first order magnetic field on the ground-state of a centered hydrogenic donor impurity in a gaas/alas spherical quantum dot has been calculated. the perturbation method has been used within the framework of effective mass approximation for these calculations. overall, the analysis shows that a proper choice of quantum dot radius and magnetic field can signifi...