Miracle-dz/UniFAR-FTUs huggingface dataset:
Active power control of a PV generator for large scale photovoltaic power plant without energy storage

The increasing renewable energy penetration together with the price reduction of photovoltaic modules is supporting the development of photovoltaic power plants connected to the medium and low voltage grid. Many concerns are emerging about the electrical system stability when it is connected to renewable sources. Usually, photovoltaic power plants are thought to reach always the maximum power point and to extract the maximum power available. However, due to the new grid codes as the ones from Puerto Rico and South Africa, the photovoltaic power plants should not always extract the maximum power available. Instead it is necessary to follow a fix reference due to power curtailment, power reserve or ramp rate. Thus, this article proposes a control method to comply active power requirements by modifying a tracking algorithm. For this purpose, a photovoltaic generator is modelled and controlled in DIgSILENT PowerFactory. The results show that the control proposed can follow a given active power reference despite the ambient conditions.
Computer-aided analyses of electric fields used in electrorotation studies

The spatial variations of the magnitude and phase of the electric field produced by electrodes used in electrorotation studies have been computed, using the charge density method at 10 degrees intervals for one complete AC cycle of the applied voltages. These results, together with the development of a more general theoretical treatment than has hitherto been applied to this problem, enable the time-averaged rotational torque and dielectrophoretic force acting on a particle to be determined as a function of its location within the inter-electrode space. Correction factors that can be applied to electrorotation spectra to take account of the relative position, or change in position, of the test particle are provided for electrodes of polynomial and circular geometry.
3D Digitization of Human Foot Based on Computer Stereo Vision Combined with KINECT Sensor

It is significant for shoe-making industry to develop three-dimension digital models of human foot. In this paper, a system combining a computer stereo vision with a KINECT sensor was proposed. Based on the system, an algorithm of feature extraction and matching was examined. Experiments show that the system and relevant algorithms are successful for 3D digitization of human foot. The proposed method could be further developed to obtain characteristic parameters of human feet, which can be used directly by shoe-making machines.
Sensitivity limits of millimeter-wave photonic radiometers based on efficient electro-optic upconverters

Conventional ultra-high sensitivity detectors in the millimeter-wave range are usually cooled as their own thermal noise at room temperature would mask the weak received radiation. The need for cryogenic systems increases the cost and complexity of the instruments, hindering the development of, among others, airborne and space applications. In this work, the nonlinear parametric upconversion of millimeter-wave radiation to the optical domain inside high-quality (Q) lithium niobate whispering-gallery mode (WGM) resonators is proposed for ultra-low noise detection. We experimentally demonstrate coherent upconversion of millimeter-wave signals to a 1550 nm telecom carrier, with a photon conversion efficiency surpassing the state-of-the-art by 2 orders of magnitude. Moreover, a theoretical model shows that the thermal equilibrium of counterpropagating WGMs is broken by overcoupling the millimeter-wave WGM, effectively cooling the upconverted mode and allowing ultra-low noise detection. By theoretically estimating the sensitivity of a correlation radiometer based on the presented scheme, it is found that room-temperature radiometers with better sensitivity than state-of-the-art high-electron-mobility transistor (HEMT)-based radiometers can be designed. This detection paradigm can be used to develop room-temperature instrumentation for radio astronomy, earth observation, planetary missions, and imaging systems.
Surface Generation in Ultra-precision Diamond Turning: Modelling and Practices

One of the remarkable achievements of modern manufacturing techniques is the ability to achieve nano-metre surface finishes. Ultraprecision machining based on single-point diamond turning (SPDT) is a very important technique in the manufacture of high-precision components where surface finish is critical. Complex optical surfaces, for example, can be produced without the need for post-machining polishing.
New cubic structure compounds as actinide host phases

Various compounds with fluorite (cubic zirconia) and fluorite-derived (pyrochlore, zirconolite) structures are considered as promising actinide host phases at immobilization of actinide-bearing nuclear wastes. Recently some new cubic compounds — stannate and stannate-zirconate pyrochlores, murataite and related phases, and actinide-bearing garnet structure compounds were proposed as perspective matrices for complex actinide wastes. Zirconate pyrochlore (ideally Gd2Zr2O7) has excellent radiation resistance and high chemical durability but requires high temperatures (at least 1500 °C) to be produced by hot-pressing from sol-gel derived precursor. Partial Sn4+ substitution for Zr4+ reduces production temperature and the compounds REE2ZrSnO7 may be hot-pressed or cold pressed and sintered at ~1400 °C. Pyrochlore, A2B2O7−x (two-fold elementary fluorite unit cell), and murataite, A3B6C2O20−y (three-fold fluorite unit cell), are end-members of the polysomatic series consisting of the phases whose structures are built from alternating pyrochlore and murataite blocks (nano-sized modules) with seven- (2C/3C/2C), five- (2C/3C), eight- (3C/2C/3C) and three-fold (3C — murataite) fluorite unit cells. Actinide content in this series reduces in the row: 2C (pyrochlore) > 7C > 5C > 8C > 3C (murataite). Due to congruent melting murataite-based ceramics may be produced by melting and the firstly segregated phase at melt crystallization is that with the highest fraction of the pyrochlore modules in its structure. The melts containing up to 10 wt. % AnO2 (An = Th, U, Np, Pu) or REE/An fraction of HLW form at crystallization zoned grains composed sequentially of the 5C → 8C → 3C phases with the highest actinide concentration in the core and the lowest — in the rim of the grains. Radiation resistance of the "murataite" is comparable to titanate pyrochlores. One more promising actinide hosts are ferrites with garnet structure. The matrices containing sometime complex fluorite structure oxide as an extra phase have leach and radiation resistance similar to the other well-known actinide waste forms.
Mechanical Property Measurements and Fracture Propagation Analysis of Longmaxi Shale by Micro-CT Uniaxial Compression

The mechanical properties and fracture propagation of Longmaxi shale loading under uniaxial compression were measured using eight cylindrical shale specimens (4 mm in diameter and 8 mm in height), with the bedding plane oriented at 0° and 90° to the axial loading direction, respectively, by micro computed tomography (micro-CT). Based on the reconstructed three-dimensional (3-D) CT images of cracks, different stages of the crack growth process in the 0° and 90° orientation specimen were revealed. The initial crack generally occurred at relatively smaller loading force in the 0° bedding direction specimen, mainly in the form of tensile splitting along weak bedding planes. Shear sliding fractures were dominant in the specimens oriented at 90°, with a small number of parallel cracks occurring on the bedding plane. The average thickness and volume of cracks in the 90° specimen is higher than those for the specimen oriented at 0°. The geometrical characterization of fractures segmented from CT scan binary images shows that a specific surface area correlates with tortuosity at the different load stages of each specimen. The 3-D box-counting dimension (BCD) calculations can accurately reflect crack evolution law in the shale. The results indicate that the cracks have a more complex pattern and rough surface at an orientation of 90°, due to crossed secondary cracks and shear failure.
Evaluation of a Distributed Photovoltaic System in Grid-Connected and Standalone Applications by Different MPPT Algorithms

Due to the shortage of fossil fuel and the environmental pollution problem, solar energy applications have drawn a lot of attention worldwide. This paper reports the use of the latest patented distributed photovoltaic (PV) power system design, including the two possible maximum power point tracking (MPPT) algorithms, a power optimizer, and a PV power controller, in grid-connected and standalone applications. A distributed PV system with four amorphous silicon thin-film solar panels is used to evaluate both the quadratic maximization (QM) and the Steepest descent (SD) MPPT algorithms. The system’s design is different for the QM or the SD MPPT algorithm being used. The test result for the grid-connected silicon-based PV panels will also be reported. Considering the settling time for the power optimizer to be 20 ms, the test result shows that the tracking time for the QM method is close to 200 ms, which is faster when compared with the SD method whose tracking time is 500 ms. Besides this, the use of the QM method provides a more stable power output since the tracking is restricted by a local power optimizer rather than the global tracking the SD method uses. For a standalone PV application, a solar-powered boat design with 18 PV panels using a cascaded MPPT controller is introduced, and it provides flexibility in system design and the effective use of photovoltaic energy.
Energy Conservation In Thermal Power Courses

What should technology and engineering students know about energy conservation? Traditional energy technologies, such as coal-fired power plants and petroleum-based internal combustion engines, will continue to dominate modern society for the short term. However, evidence of global warming, ozone depletion, and other environmental concerns are beginning to bring energy conservation issues to the forefront. The purpose of this paper is to encourage discussions about how broad concepts like “renewable energy” is treated in undergraduate thermal power courses. Renewable energy use in the United States The data summarized in Figure 1 shows that renewable sources deliver only a small part of the annual energy used in the United States. Coal, petroleum, and natural gas were responsible for more than 85% of the nearly 100 quadrillion Btu’s consumed by the United States in 1999. Renewable sources, which include hydroelectric, solar, and wind energy, contribute approximately 8% of the total. Nuclear electric sources, which the Department of Energy does not categorize as “renewable”, make up the remaining 7% of the energy consumed. Based on this data, one might conclude that undergraduate thermal power courses should continue to focus exclusively on “traditional” thermodynamic topics. At first glance, it seems reasonable to emphasize topics that students will typically encounter during their early careers. Figure 1. Renewable energy sources are a small part of total U.S. energy consumption. natural gas 24% petroleum 39% coal 23% nuclear electric 7% solar 1%
Study of New Derivatives of 1,3,4-Thiadiazole and Its Complexes with chromium ion (Cr+3)

The present study included preparing a new ligand from the thiadiazole derivative 2,5-dihydrazineyl-1,3,4-thiadiazol with 4-Dimethyl amino benzyaldehyde with a ratio of (1:2) to preparing the ligand (L1) Transition ion complexe (Cr3+) were prepared with ligand (L1) and ligand and its complexe were diagnosed using the elemental analysis (C.H.N.S), Infrared spectrum (FTIR), Proton nuclear magnetic resonance spectrum (1H-NMR), Mass spectroscopy, magnetic sensitivity and molar conductivity, the practical results were exactly in line with the molecular formula and structural formulas for the compounds.The results obtained from the study of magnetic sensitivity and molar conductivity of the prepared ligand complexe confirmed that the geometry shape of [L1CrCl2]Cl is an octahedral complex . The results of molar conductivity also confirmed that the prepared Chromium complexes is electrolytic . The biological efficacy of the prepared ligand and its complexity were tested against two type of bacteria Staphylococcus aureus and Escherichia Coli in comparison with the standard inhibitor (Ciprofloxacin) , the obtained results confirmed the biological efficacy of the prepared ligand above that of the standard inhibitor (Cipro) , against of the bacteria Escherichia coli, also the complexe (X1) showed higher biological efficacy than standard inhibitor (Cipro) against Escherichia coli (Gram negative), the ligand and its prepared complexe don’t showed biological activity against Staphylococcus aureus .
Stellar Properties and Rocky Planet Habitability: Is There a Correlation?

The properties of a rocky planet’s host star may be associated with the origin of life and the evolution of observers on that planet. By comparing the Sun to other stars in our Galaxy, we may be able to identify such properties. If our Sun is a typical star, stellar conditions appropriate for life, and life itself, may be common in the Universe. On the other hand, if the Sun is atypical or even unique, then the life orbiting the Sun may also be atypical or unique. Here we present the comparison between the Sun and stars for three important parameters that may be associated with the origin and evolution of life. We find that: i) The Sun is more massive than 95 ± 2% of nearby stars. ii) The Sun is younger than 53 ± 2% of stars in the Galactic disk. iii) The Sun is more metal rich than 65 ± 2% of nearby stars.
Ionization of Rydberg atoms by half-cycle pulses

In figure 2 of this article, the quantum calculations correspond to the statistical average of the results for all initial states within a given n level. The correct figure containing quantum calculations for l=2, m=0 initial states is shown below: Figure: Ionization probability of H(n,l = 2, m = 0) atoms as a function of the scaled momentum transfer: classical results (solid lines) and quantum mechanical results (dotted lines).
Fast and Robust Determination of Power System Emergency Control Actions

This paper outlines an optimization framework for choosing fast and reliable control actions in a transmission grid emergency situation. We consider contractual load shedding and generation re-dispatch as exemplary emergency actions. To achieve computational efficiency and scalability, this novel formulation of the robust corrective action optimization is stated in terms of voltages and currents, as opposed to standard formulation in terms of power flows and voltages. The current-voltage formulation is natural for expressing voltage and thermal transmission line constraints, and its major advantage is in the linearity of the power flow equations. The complexity of the current-voltage formulation, which is mainly related to the transformation of voltages and currents into active and reactive power injections, can be largely avoided by stating the cost function directly in terms of currents and using linearized or robust estimates for load and generation constraints. The paper considers five different optimization problem formulations, including the full current-voltage formulation, as well as two convex and two linear approximation to the problem. In a case study on an illustrative case study for the IEEE RTS96 system, we demonstrate pros and cons of the different formulations based on simulations for both normal and contingency operation.
THE SEASONALITY EXPRESSED IN MOTILITY OF FROG RANA RIDIBUNDA PALL 1771 ERYTHROCYTES AND LEUKOCYTES IN AGAROSE GEL UNDER THE INFLUENCE OF THE TEMPERATURE

*** ABSTRACT The agarose migration test revealed the influence of temperature on seasonal fluctuation of locomotional activity of nuclear hemocytes of frogs of the genus Rana ridibunda Pall. It’s been shown that at different incubation temperatures, the spontaneous migration area of blood cells changed in spring and summer, and did not change during autumn and winter. It’s been found that the migratory activity of erythrocytes and leukocytes in the spring increased only at low incubation temperature, in the summer both at low and at high
Dosimetry using plane-parallel ionization chambers in a 75 MeV clinical proton beam

Reference ionization chamber dosimetry in clinical proton beams is generally performed with cylindrical ionization chambers. However, when the measurement is performed in the presence of a large depth dose gradient or in a narrow spread out Bragg peak (SOBP), it could be advisable to use a plane-parallel chamber. Few recommendations and studies have been devoted to this subject. In this paper, experimental information on perturbation correction factors for four plane-parallel ionization chamber types in proton beams is presented. The experiments were performed in 75 MeV modulated and non-modulated proton beams. Monte Carlo calculations have been performed to support the conclusions of the experimental work. Overall, we were not able to find experimental evidence for significant differences between the secondary electron perturbation correction factors for plane-parallel chambers and those for a cylindrical NE2571. We found experimental ratios of perturbation correction factors that did not differ by more than 0.6% from unity for a Roos and two NACP02 chambers, and by not more than 1.2% for a Calcam-2 and two Markus chambers. Monte Carlo simulations result in corrections that are limited to 0.6% in absolute value, but given the overall uncertainties of the measurements, the deviations of the correction factors from unity could not be resolved from the experimental results. The results of the simulations thus support the experimental conclusion that perturbation correction factors for the set of plane-parallel chambers in both proton beams (relative to NE2571) do not deviate from unity by more than 1.2%. This confirms, within the experimental uncertainties, the assumption that the overall perturbation correction factor for a plane-parallel chamber in a low-energy proton beam is unity, made in IAEA TRS-398 and other dosimetry protocols. Given the large uncertainties of the gradient correction factors to be applied when using a cylindrical ionization chamber in a narrow SOBP or in the presence of a strong depth dose gradient, the level of agreement between plane-parallel and cylindrical ionization chambers observed in this study shows that plane-parallel chambers are a reliable alternative for reference dosimetry in low-energy proton beams.
Symplectic invariants, entropic measures and correlations of Gaussian states

We present a derivation of the Von Neumann entropy and mutual information of arbitrary two-mode Gaussian states, based on the explicit determination of the symplectic eigenvalues of a generic covariance matrix. The key role of the symplectic invariants in such a determination is pointed out. We show that the Von Neumann entropy depends on two symplectic invariants, while the purity (or the linear entropy) is determined by only one invariant, so that the two quantities provide two different hierarchies of mixed Gaussian states. A comparison between mutual information and entanglement of formation for symmetric states is considered, taking note of the crucial role of the symplectic eigenvalues in qualifying and quantifying the correlations present in a generic state.
Wavelet Decomposition and Convolutional LSTM Networks Based Improved Deep Learning Model for Solar Irradiance Forecasting

Solar photovoltaic (PV) power forecasting has become an important issue with regard to the power grid in terms of the effective integration of large-scale PV plants. As the main influence factor of PV power generation, solar irradiance and its accurate forecasting are the prerequisite for solar PV power forecasting. However, previous forecasting approaches using manual feature extraction (MFE), traditional modeling and single deep learning (DL) models could not satisfy the performance requirements in partial scenarios with complex fluctuations. Therefore, an improved DL model based on wavelet decomposition (WD), the Convolutional Neural Network (CNN), and Long Short-Term Memory (LSTM) is proposed for day-ahead solar irradiance forecasting. Given the high dependency of solar irradiance on weather status, the proposed model is individually established under four general weather type (i.e., sunny, cloudy, rainy and heavy rainy). For certain weather types, the raw solar irradiance sequence is decomposed into several subsequences via discrete wavelet transformation. Then each subsequence is fed into the CNN based local feature extractor to automatically learn the abstract feature representation from the raw subsequence data. Since the extracted features of each subsequence are also time series data, they are individually transported to LSTM to construct the subsequence forecasting model. In the end, the final solar irradiance forecasting results under certain weather types are obtained via the wavelet reconstruction of these forecasted subsequences. This case study further verifies the enhanced forecasting accuracy of our proposed method via a comparison with traditional and single DL models.
Evaluation of the structural capacity of rigid pavements at the network level

Pavement surface deflection has been used by researchers and highway agencies to assess the structural condition of the pavement structure. None of the currently available approaches provides an acceptable evaluation method for the rigid pavement structural capacity at the network level. In this research, pavement structural ratio (PSR) and overall pavement structural index (OPSI) were derived from deflection bowls generated from finite element simulations and validated by actual field deflection data measured by falling weight deflectometer and performance data extracted from long-term pavement performance database. The PSR parameter provides structural evaluation of the rigid pavement slab and the base course above the subgrade only. Whereas, OPSI parameter provides an overall evaluation of the pavement structure and the subgrade.
EEG-distributed inverse solutions for a spherical head model

The theoretical study of the minimum norm solution to the MEG inverse problem has been carried out in previous papers for the particular case of spherical symmetry. However, a similar study for the EEG is remarkably more difficult due to the very complicated nature of the expression relating the voltage differences on the scalp to the primary current density (PCD) even for this simple symmetry. This paper introduces the use of the electric lead field (ELF) on the dyadic formalism in the spherical coordinate system to overcome such a drawback using an expansion of the ELF in terms of longitudinal and orthogonal vector fields. This approach allows us to represent EEG Fourier coefficients on a 2-sphere in terms of a current multipole expansion. The choice of a suitable basis for the Hilbert space of the PCDs on the brain region allows the current multipole moments to be related by spatial transfer functions to the PCD spectral coefficients. Properties of the most used distributed inverse solutions are explored on the basis of these results. Also, a part of the ELF null space is completely characterized and those spherical components of the PCD which are possible silent candidates are discussed.