The spurious eigenvalues of an annular domain have been verified for the singular and hypersingular boundary‐element methods (BEMs) circumvented by using Burton‐Miller approach. Do they also occur in other formulations: continuous formulations such as boundary integral equations (BIEs), null‐field BIEs fictitious BIEs, or discrete BEMs BEMs? For ten multiply connected problem study otherwise same issues is continued present paper. By degenerate kernels Fourier series, it demonstrated...

A feeding trial was conducted to study the effect of partial replacement dietary monocalcium phosphate (MCP) with neutral phytase on growth performance and phosphorus digestibility in gibel carp, Carassius auratus gibelio (Bloch). Control diet prepared 2% MCP but without (P0). Other three experimental diets were by 25%, 50% 75% respectively comparison control supplementation at 500 U kg−1 each designated as P25, P50 P75 respectively. Gibel carp (initial body weight 30.22 ± 1.98 g) reared...

Abstract In this paper, the eigenanalysis for multiply‐connected domain problem is studied by using dual boundary element method. The occurrence and treatment of spurious eigenvalues are reviewed when complex‐valued BEM in used. Three approaches, Burton Miller method, CHIEF concept SVD updating techniques, adopted to suppress eigensolutions. Instead singular hypersingular formulations, singularity‐free methods, null‐field equation approach fictitious BEM, also utilized deal with...

A description of yield surfaces in the axial-torsional-hoop stress space, which is able to capture surface expansion/contraction, translation, rotation, affine deformation, and distortion, constructed under a three-dimensional point view. Starting from theory cubic polynomials two-dimensional spaces, authors first clarify relations between it Kurtyka Życzkowski exhibits excellent performance fitting experimental data points space. Because an arbitrary polynomial does not guarantee that its...

The three-dimensional (3D) displacement field in elastic body subjected to force usually governed by the Navier-Cauchy equation is here formulated language of Clifford valued functions and Dirac operator. Using analysis considering arbitrary force, we solve problem, expressing terms one harmonic function monogenic function.

A bridge with the functional bearing system, where sticking-sliding mechanism of rubber reduces force transmission between substructure and superstructure, shows viscoelastoplastic behavior. In present paper, we show a simplified two-degree-of-freedom (2DOF) model for system containing Coulomb’s friction element that displays mechanical behavior including sticking (viscoelastic) sliding (viscoplastic) modes arrange its mathematical formulation into two-phase framework which is...

A Lie-group differential algebraic equations (LGDAE) method, which is developed for solving differential-algebraic equations, a simple and effective algorithm based on the Lie group GL(n,R) Newton iterative scheme. This paper deepens theoretical foundation of LGDAE method widens its practical applications to solve nonlinear mechanical systems with nonholonomic constraints. After obtaining closed-form formulation elements one-parameter refining this split applied nine problems mechanics in...

In this paper, a quaternion boundary element method (BEM) is proposed to solve the magnetostatic problem. The present quaternion-valued BEM developed by discretizing integral equation (BIE). BIE can be seen as an extension of generalized complex variable in 3-D space. other words, algebra To derive BIEs, Stokes' theorem utilized. BIEs are noted for singularity, which exists sense Cauchy principal value (CPV). An analytical scheme evaluate CPV introducing simple harmonic function. For domain...

A dual integral formulation for the Laplace problem with a smooth boundary is derived by using contour approach surrounding singularity. It found that jump terms come half and from free in L M kernel integrations two-dimensional case, which different limiting process approaching an interior point to where totally only. The definition of Hadamard principal value hypersingular at collocation extended generalized sense both tangent normal derivatives double-layer potentials comparison...

The effect of CO 2 on the hydrogen permeation behaviour carbon steel was investigated in a high temperature and pressure device, through test, weight loss content SEM-EDS. results showed that peak value curves were almost same with or without , but curve rose sharply, then decreased gradually to stabilized current H S/CO environment, which lower than S environment. corrosion rates amount environment Therefore, it is considered has an S, mainly due change products.

The geometry optimization, formation energy, Mulliken populations, and density of states YAP (YAlO 3 ) crystal are studied by using first-principles method based on functional theory. optimal lattice parameters in good accordance with experimental results reported. calculated energy (-3.73eV) indicates the excellent structural stability crystal. obtained charge populations O, Al Y atoms their deviations from formal ones, as well overlap show is a mixed bond material stronger ionic weaker...

In this paper polyurethane (PU) / polyaniline (PANI) nanofibers were successfully prepared via electrospinning with N, N-dimethylformamide (DMF) and tetrahydrofuran (THF) mixture (1:2 mass ratio). The morphology, diameter structure of the electrospun examined by scanning electron microscopy (SEM) distribution was measured Image-Pro Plus. Results indicate that uniformity fibers influenced solution concentration, applied voltage, capillary–screen distance flow rate greatly, finer uniform from...

As the important device to perceive operating state of grid, condition monitoring electric equipment solves such problems as high rate false alarm and failure caused by low temperature in winter cold areas. This paper measures thermal conductivity three kinds materials asbestos, rubber nano porous aerogels range -55°C +80°C steady method, analyzes influence on materials. According result experiment, is lowest affected least among Nano apply operated areas; can also be used insulation...