nowadays with increasing use of numerous nonlinear loads, voltage and current harmonics in power systems are one of the most important problems power engineers encounter. many of these nonlinear loads, because of their dynamic natures, inject time-varying harmonics into power system. common techniques applied for harmonics measurement and assessment such as fft have significant errors in presen...

the variability of temperature and precipitation is regarded as one of the main characteristics of the climate.precipitation and its results, especially results such as droughts, vary on different temporal and spatial scales. thepurpose of this paper is to determine the frequency of the inter-annual variability of the driest month in north-westiran. in order to obtain the best results, we used ...

A force m onitoring system consisting of stress-sensitive magnetoelastic strips forremotely measuring the force profile across a hard surface is described. Under the excitation of amagnetic AC field, the m agnetoelastic strips generated higher-order harmonic fields (magneticAC fields at multiple frequencies of the excitation field), allowing remote measurement of theirresponses ...

The tip clearance, a compact gap between the inducer blade and casing wall, is critical to both liquid leakage cavitation-induced forces of turbopump. In this study, we numerically investigate effect clearance on cavitation characteristics an inducer. Six different clearances, 0.1, 0.3, 0.5, 1.0, 1.5, 2 mm, namely Models A–F, were designed evaluate performance, cavity structure, loading, radial...

this paper presents a new control method for a three-phase four-wire unified power quality conditioner (upqc) to deal with the problems of power quality under distortional and unbalanced load conditions. the proposed control approach is the combination of instantaneous power theory and synchronous reference frame (srf) theory which is optimized by using a self-tuning filter (stf) and without us...

‎We consider the oscillator group equipped with‎ ‎a biinvariant Lorentzian metric‎. ‎Some geometrical properties of this space and the harmonicity properties of left-invariant vector fields on this space are determined‎. ‎In some cases‎, ‎all these vector fields are critical points for the energy functional‎ ‎restricted to vector fields‎. ‎Left-invariant vector fields defining harmonic maps are...

We study non-Gaussianity induced by a pseudo Nambu-Goldstone boson with a cosine-type scalar potential. We focus on how the non-Gaussianity is affected when the pseudo Nambu-Goldstone boson rolls down from near the top of the scalar potential where the deviation from a quadratic potential is large. We find that the resultant non-Gaussianity is similar to that obtained in the quadratic potential...

The paper is devoted to the solution of the inverse boundary problem for the heat equation. Let Ω be a connected bounded domain in R n (n ≥ 2) with C l (l ≥ 2) boundary Γ. Consider the mixed problem for the heat equation (1.1)        (ρ(x)∂ t − −)u f (t, x) = 0 in (0, +∞) × Ω, u f (t, x) = f (t, x) o n(0 , +∞) × Γ, u f (0, x) = 0 on Ω. The density ρ(x) is a C l+σ , 0 < σ < 1, function on...

This paper presents a novel apparatus, combined with application of the Virtual Fields Method (VFM) for high frequency characterisation mechanical response ultra-soft materials. The viscoelastic is characterised under harmonic deviatoric loading at range frequencies using dynamic VFM in domain. Obtaining useful rate data on soft materials challenging typical test methodologies, as low speed sou...

In this work, we derive a closed-form criterion for the onset of cavitation in compressible, isotropic, hyperelastic solids subjected to non-symmetric loading conditions. The criterion is based on the solution of a boundary value problem where a hyperelastic solid, which is infinite in extent and contains a single vacuous inhomogeneity, is subjected to uniform displacement boundary conditions. ...