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Experiments of a steel sphere oblique impact with a rubber cushion have been proceeded to research the variation laws of the specific energy at interface. The contact surfaces above and under the rubber cushion can be recorded with a thin carbon paper. The parameters of deformation volume and specific energy are analyzed by the developed formulas in different cases of the impact angle, cushion thickness, drop height and sphere diameter. It is found that the deformation volume and related geometrical sizes decrease approximately exponentially with the impact angle, and the volume of the tangential moving part reaches a maximum at 50° or 60°. The variation laws of the specific energy absorption/dissipation in normal are similar to that of the axis length. The tangential specific energy can be divided into three main phases, the first two appear the states of slow increase and plateau, between of them a fluctuating peak exists at 30–40°. In final phase, the energy absorption shows sharp increase, but the energy dissipation first increases and then decreases. In addition, they increase linearly with the drop height and sphere diameter, and an optimum cushion thickness of 4 or 5 mm in the given cases. [ABSTRACT FROM AUTHOR]

The partial shading effect (PSE) is responsible for most power losses in a photovoltaic (PV) system. By modifying the interconnections between PV modules, called PV array reconfiguration, it is possible to improve the power output under partial shading conditions (PSCs). Compared to research on static PSCs, the impact of dynamic PSCs on PV arrays is rarely mentioned, although it deserves to be studied. This paper studies the dynamic PSE on four traditional PV configurations and two reconfiguration techniques based on a 5 × 5 PV array. The four traditional PV configurations are Series-Parallel (SP), Bridge-Link, Honey-Comb, and Total-Cross-Tied (TCT). The two reconfiguration techniques are SuDoKu (SDK) representing Physical Array Reconfiguration (PAR) and Electrical Array Reconfiguration (EAR). The dynamic PSCs are simplified to three types based on the varying orientation: horizontal, vertical, and diagonal. Simulations are carried out with Matlab & Simulink. The performance comparison for the four traditional PV array and two reconfiguration techniques is based on daily energy losses. The results show that four traditional PV configurations techniques, in all PSCs' scenarios, EAR has the most stable performance and the lowest energy losses. The energy losses of SP connection are the largest in all PSCs cases. Although their performance varies depending on the partial shading case, Total-Cross-Tied and SudoDKu lead to the lowest energy losses. [ABSTRACT FROM AUTHOR]

Proper EMA-balance (balance of kinetic energy, linear momentum and angular momentum), pressure-robustness and Re-semi-robustness (Re: Reynolds number) are three important properties of Navier–Stokes simulations with exactly divergence-free elements. This EMA-balance makes a method conserve kinetic energy, linear momentum and angular momentum in an appropriate sense; pressure-robustness means that the velocity errors are independent of the pressure; Re-semi-robustness means that the constants appearing in the error bounds of kinetic and dissipation energies do not explicitly depend on inverse powers of the viscosity. In this paper, based on the pressure-robust reconstruction framework and certain suggested reconstruction operators in Linke and Merdon [Comput. Methods Appl. Mech. Eng.311 (2016) 304–326], we propose a reconstruction method for a class of non-divergence-free simplicial elements which admits almost all the above properties. The only exception is the energy balance, where kinetic energy should be replaced by a suitably redefined discrete energy. The lowest order case is the Bernardi–Raugel element on general shape-regular meshes. Some numerical comparisons with exactly divergence-free methods, the original pressure-robust reconstruction methods and the EMAC method are provided to confirm our theoretical results. [ABSTRACT FROM AUTHOR]

In this work, we examine the performance of novel dyes as photosensitizers in dye-sensitized solar cells. We use density functional theory calculations to explore the energy levels, absorption wavelengths, and photovoltaic characteristics of these dyes. The calculated energy levels show appropriate alignment with electron transport layers, guaranteeing efficient charge injection and reducing energy losses. These dyes also exhibit absorption wavelengths in the visible range, indicating that they are capable of efficiently harnessing solar energy. Analysis of their photovoltaic properties has demonstrated their potential in terms of the open circuit voltage. The dyes show favorable properties, making them potential candidates for efficient light absorption and electron transfer in dye-sensitized solar cells. These results underline the need to include them in future dye-sensitized solar cells research and provide interesting pointers for the design and optimization of efficient photosensitizers. [ABSTRACT FROM AUTHOR]

Context. Pressure profiles are sensitive probes of the thermodynamic conditions and the internal structure of galaxy clusters. The intra-cluster gas resides in hydrostatic equilibrium within the dark-matter gravitational potential. However, this equilibrium may be perturbed; for example, as a consequence of thermal energy losses, feedback, and non-thermal pressure supports. Accurate measures of the gas pressure over cosmic time are crucial for constraining cluster evolution as well as the contributions from astrophysical processes. Aims. In this work we present a novel algorithm for deriving the pressure profiles of galaxy clusters from the Sunyaev-Zeldovich (SZ) signal measured on a combination of Planck and South Pole Telescope (SPT) observations. The synergy of the two instruments makes it possible to track the profiles on a wide range of spatial scales. We exploited the sensitivity of the Planck High-Frequency Instrument to the larger scales in order to observe the faint peripheries, and took advantage of the higher spatial resolution of SPT to solve the innermost regions. Methods. We developed a two-step pipeline to take advantage of the specifications of each instrument. We first performed a component separation on the two data sets separately in order to remove the background (CMB) and foreground (Galactic emission) contaminants. We then jointly fitted a parametric pressure profile model on a combination of Planck and SPT data. Results. We validated our technique on a sample of six CHEX-MATE clusters detected by SPT. We compare the results of the SZ analysis with profiles derived from X-ray observations with XMM-Newton. We find excellent agreement between these two independent probes of the gas pressure structure. [ABSTRACT FROM AUTHOR]

Aims. We used solar observations of a plage-enhanced network with the Atacama Large Millimeter/sub-millimeter Array (ALMA) in Band 3 and Band 6, together with synthetic continuum maps from numerical simulations with Bifrost in the same bands, to carry out a detailed study of bright small-scale magnetic features. Methods. We made use of an algorithm to automatically identify and trace bright features within the field of view (FoV) of the ALMA observations and the simulation. In particular, the algorithm recovers information of the time evolution of the shape, motion of the centre of gravity, temperature, and size for each feature. These quantities are used to determine the oscillatory properties of each feature utilising wavelets analysis. Results. We found 193 and 293 features in the Bands 3 and 6 observations, respectively. In the degraded simulation, the total number of features were 24 for Band 3 and 204 for Band 6. In the original simulation, the total number of features were 36 for Band 3 and 392 for Band 6. Based on the simulation, we confirm the magnetic nature of the features. We have obtained average oscillation periods of 30–99 s for the temperature, 37–92 s for size, and 37–78 s for horizontal velocity. There are indications for the possible presence of transverse (kink) waves with average amplitude velocities of 2.1–5.0 km s−1. We find a predominant anti-phase behaviour between temperature and size oscillations suggesting that the variations of the bright features are caused by compressible fast-sausage magnetohydrodynamics (MHD) modes. For the first time to our knowledge, we estimated the flux of energy of the fast-sausage waves at the chromospheric heights sampled by ALMA as 453–1838 W m−2 for Band 3 and 3640–5485 W m−2 for Band 6. Conclusions. We have identified MHD waves, both transverse (kink) and compressible sausage modes, in small-scale (magnetic) structures, independently, in both ALMA Band 3 and Band 6 observations, along with their corresponding synthetic images from simulations. The decrease of wave energy-flux with height (from Band 6 to Band 3) could possibly suggest energy dissipation at chromospheric heights, namely, wave heating, with the assumptions that the identified small-scale waves are typical at each band and they propagate upward through the chromosphere. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) modules in service undergo more or less severe degradation depending on their operating environments, ages and technologies. In this work, we investigated the coupled influence of the climatic conditions of operation and of the degree of deterioration of a PV module on its energy production. We considered four silicon PV modules characterized in standard test conditions. The PV conversion is modeled by a single diode model taking into account the presence of a fault. Matlab/Simulink software was used to calculate the energy supplied at a constant load for the PV module with and without defects. The ratio between the energy produced with fault and without fault allowed to quantify the percentage of loss. This loss was plotted according to the degrees of degradation of the short-circuit current Isc, the open-circuit voltage Voc, the series resistance Rs and the shunt resistance Rsh. It is shown that when irradiance is held constant, the energy loss is lower with increasing temperature for Isc and Rsh, and vice versa for Voc and Rs. While the temperature is kept constant, the energy loss is lower when the irradiance increases for Isc and Rsh, and inversely for Voc and Rs. A multicriteria analysis enabled to determine the most robust module among the four ones. [ABSTRACT FROM AUTHOR]