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Ferruginous stromatolites occur associated with Middle Jurassic condensed deposits in several Tethyan and peri‐Tethyan areas. The studied ferruginous stromatolites occurring in the Middle Jurassic condensed deposits of Southern Carpathians (Romania) preserve morphological, geochemical, and mineralogical data that suggest microbial iron oxidation. Based on their macrofabrics and accretion patterns,...
The anisotropy of the magnetic materials is an important parameter in many cases, especially in modern applications, like sensors or drives. This paper proposes a new approach to the study of the behavior of the intrinsic and extrinsic properties of these materials depending of the orientation of the sample in a magnetic field. By controlling a Vibrating sample magnetometer (VSM), it could be possible...
We propose a new method for segmenting indoor scenes captured with RGBD or depth cameras with a simple and fast iterative CPU segmentation. The segmentation consists of three main steps. In the first stage, regions grow by adding new pixels based on depth information and normal vectors. Next, multiple regions are merged into bigger surfaces based on adjacency and region statistics. The last stage...
A new formula for the hysteresis losses prediction at higher magnetic fields is proposed. Its efficiency is tested both for sinusoidal and non-sinusoidal waveforms, applied for non-oriented magnetic FeSi sheets of various sorts, which are used for electrical machine cores. The model parameters are identified starting for laboratory measurements made by a standardized single sheet tester (SST). The...
The paper presents the analytical solution for the i-Φ magnetic characterization for two different types of iron-core devices (small rated power inductors, reactors or chokes) widely encountered in electronic circuitry. The proposed method bases on the fundamental laws of electromagnetism and a special adopted function for the H-B curve description of the core laminations. The manufacturer data are...
The actual high incidence of the low-loss power transformers in the modern electric and electronic installations, increase the risk of the ferroresonance occurrence. This could be commonly triggered by a capacitive switching of the transformers. Consequently, significant overvoltages and overcurents are experienced by all the installation components, jeopardizing their proper functionality. Additionally,...
The currently high energy efficiency demands and control requirements impose an extensive usage of power electronic devices and circuits in both domestic and industrial applications. These intrinsic nonlinear loads generate prominent level distortion of the electric current waveforms, which lead to additional losses and thermal stress within the power supply distribution system. Thus, due to the supplementary...
The actual energy efficiency requirements generated a large usage of the power electronic converters for driving asynchronous motors in numerous industrial facilities. The associated power quality issues of these adjustable speed drives, especially harmonic currents, adversely affect the power distribution transformers by increasing their losses and decreasing their life time expectancy. Accordingly,...
Staircases are among the most common architectural features in urban environments. In this paper, we describe a method for detecting indoor staircases from depth images. The objective of this development is to aid visually impaired people in perceiving the environment, especially in unfamiliar places. This method is based on the detection and clustering of patches that have the surface normal vectors...
For different sorts of electrical sheets, the magnetic losses separation using Bertotti method was performed. Using a fitting procedure, the Steinmetz coefficients were approximated. For each parameter, an analytical expression regarding the measured values was determinated. Finally, a comparison between the measured data and the predicted losses was made. The modeled losses are quite close to the...
A study on the possible corrections of the measured magnetization curves for magnetite (Fe3O4) nanoparticles is presented. The same nanopowder was measured using various sample shapes (cylinders, thin films) allowed by the VSM holders, which impose a specific packing fraction, and under different orientations of the applied magnetic field. Demagnetizing factors and effective field approaches are tried,...
The paper presents a fast and efficient method for determining the solutions of the ferroresonant circuits generated at the switching of different single-phase low-voltage iron-core devices. These are widely encountered in modern electric installations as no-loaded power transformers, magnetic choke or shunt reactors. The here suggested procedure basically relies on the solutions of the nonlinear...
The aim of this paper is to evaluate 4 sorts of non-oriented (NO) sheets used for electrical machines. The measurements were performed using Single Sheet Tester. The magnetic materials were evaluated for different values of the peak magnetic polarization and for a range of frequencies from 10 to 200 Hz. Finally, using the Steinmetz' method, the specific magnetic losses were predicted for an operating...
The aim of this paper is to compare the conductive losses in a planar transformer windings working at different waveforms used in electronics. The windings losses are determinated for each case regarding to the harmonic spectrum and considering the resistance of the copper variation with the frequency.
RGBD cameras are used in many fields, such as monitoring, robot navigation and assistive solutions for visually impaired people. The advance in technology led to the development of cheap and easy to use cameras, such as Kinect, that gained a lot of popularity. One of the technologies that allow the capturing of depth maps, the D component in RGBD sequences, is structured light. The main drawback of...
The estimation of magnetic losses in a non-oriented grains FeSi sheet by a time-dependent method is used in the paper for underlining the influence of each harmonic initial phase. The initial phase of the first harmonic, usually indicated by a power analyzer to be zero, is very important for the signal shape, the losses being dependent on this parameter. The paper proves that THD and the harmonic...
In this paper the virtual deferred algorithm is introduced, which combines the benefits of virtual texturing and deferred rendering in order to minimize the bandwidth consumption in rasterized based rendering. The proposed algorithm improves the performance of rendering by minimizing the number of expensive memory accesses such as texture fetches, which are usually the main catalysts for performance...
Hysteresis phenomenon is currently met in magnetic materials characterization. From many years this hysteresis had been modeled with different approaches. The aim of this paper is to present a comparison between few sigmoid functions used more often in other research areas. The functions were updated according to the requirements of the magnetic hysteresis and there comparisons for three different...
The paper analysis both numerically and experimentally the no-load miniature power transformer energizing process. The transient state characterization targets the predetermination of the main inrush current features: amplitude, duration and waveform signature. The whole quantitative investigation is carried out on a particular core-shaped devices (E+I), widely used in small power applications. The...
Atrial fibrillation is often asymptomatic, but outcomes require further characterization. The study objective was to investigate the clinical presentation, management, and outcomes in asymptomatic and symptomatic patients with atrial fibrillation who were prospectively enrolled in the EurObservational Research Programme – Atrial Fibrillation (EORP-AF) Pilot General Registry.A total of 3119 patients...
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