Aim. Analysis of used bits revealed the effect when tungsten carbide insert cutter was scrolling around its axis. Therefore, task to study causes this phenomenon. Hardness measured followed by setting hardness distribution gradient in section hole, order evaluate strength parameters steel zone hole. Method. Applying a well-tested method, namely method successive approximations, we determined es...

Historically square or almost spacing design has been used in plantation forest, as it claimed to maximize productivity. In this study, based on field experiments established the mid-1980s, we tested effect of different rectangular planting designs (2 × 2, 1.33 3, 1 4, 0.8 5, 1.46 4 m) productivity, stand heterogeneity, and external wood properties three coniferous species: Scots pine, Lodgepol...

A novel method for distributed estimation of the frequency of power systems is introduced based on the cooperation between multiple measurement nodes. The proposed distributed widely linear complex Kalman filter (D-ACKF) and the distributed widely linear extended complex Kalman filter (D-AECKF) employ a widely linear state space and augmented complex statistics to deal with unbalanced system co...

The objective of this study was to investigate the performance pipelines repaired with carbon-fibre-reinforced polymer (CFRP) under external pressure. pipeline experienced defects in terms thinning its local inner wall. three-dimensional finite element method used analyse collapse pressure pipes internal corrosion defects. traction–separation law and interlaminar damage criterion were applied s...

Based on the acoustic wave finite element (AWFE) method, one can establish an AWFE method and study influence of mechanical parameters shale reservoir propagation characteristics. The different crack characteristics multi-physical coupling phenomena are studied by using gas cracks. To calculate shape position along near a side borehole, model compared with simulation results. reflection wavefor...

The influence that parameters crookedness and taper have on the stack volume was analyzed by using a 3D-simulation model in this study. To do so, log length, diameters at midpoint both ends, crookedness, bark thickness, ovality were measured 1000 logs of Scots pine. From database, several data sets with different proportions crooked tapered as well degrees created taken basis to simulate stacks...

Cryoballoon ablation (CBA) has been widely accepted as a major technic for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). PV anatomy is an important factor to obtain circumferential balloon adhesion that results occlusion achieve acute PVI. The KODEX-EPD (Philips, Amsterdam, Netherlands) dielectric-based electroanatomic mapping system can display panoramic (PANO) view...

In this paper, the response surface methodology (RSM) and finite element (FE) simulation were applied to optimize push-bending process parameters of thin-walled tube with polyurethane mandrel. The objective present work is predict optimal set including length diameter ratio mandrel (L/D), friction coefficient between die ( $${\mu }_{1}$$ ), }_{2}$$ Poisson’s $$\upsilon$$ ) obtain qualified bent...

In this paper, a novel two-dimensional (2D) direction-of-arrival (DOA) estimation algorithm for the mixed circular and strictly noncircular sources is proposed. A general array model with a mixture of signals is firstly built based on uniform rectangular arrays (URAs), and then, the approach, which uses the rank-reduction-based ROOT-MUSIC, can solve 2D DOA estimation problem. Besides, the theor...