Energy Of Ejecta Research Articles

Directional soft jumper by harnessing asymmetric snapping of a semi-open shell

Precise control of the jumping direction and trajectory of soft robotics poses a challenge due to their large deformation and low stiffness. In this paper, we propose a pneumatic soft actuator consisting of an inward semi-spherical shell with a pre-existing T-shaped incision, which exhibits asymmetric snapping-through buckling under an increasing internal pressure. During the dynamic snapping, the shell deforms rapidly, resulting in an asymmetric, inclined impact with the ground. The impact force drives the soft actuator to jump in a controllable direction, and the adopted semi-open pneumatic system greatly improves the efficient utilization of air ejection energy. This design not only enhances the jumping performance, but also allows the control of the trajectory through adjusting the air pressure. Our experiments demonstrate that the actuator can achieve various jumping functions, for examples, to jump over obstacles of varying heights and depths, to execute rapid and continuous locomotion, and even to escape from a deep bottle. This work offers a paradigmatic idea for designing highly maneuverable and controllable soft robots.

Physics of nova outbursts: Theoretical models of classical nova outbursts with optically thick winds on 1.2 M⊙ and 1.3 M⊙ white dwarfs

Abstract We present time-dependent nova outburst models with optically thick winds for 1.2 and 1.35$\, M_{\odot }$ white dwarfs (WDs) with a mass-accretion rate of $5 \times 10^{-9}\, M_{\odot }$ yr−1 and for a 1.3$\, M_{\odot }$ WD with $2 \times 10^{-9}\, M_{\odot }$ yr−1. The X-ray flash occurs 11 d before the optical peak of the 1.2$\, M_{\odot }$ WD and 2.5 d before the peak of the 1.3$\, M_{\odot }$ WD. The wind mass-loss rate of the 1.2$\, M_{\odot }$ WD (1.3$\, M_{\odot }$ WD) reaches a peak of $6.4 \times 10^{-5}\, M_{\odot }$ yr−1 ($7.4 \times 10^{-5}\, M_{\odot }$ yr−1) at the epoch of the maximum photospheric expansion with the lowest photospheric temperature of log Tph (K) = 4.33 (4.35). The nuclear energy generated during the outburst is lost in the form of radiation (61% for the 1.2$\, M_{\odot }$ WD; 47% for the 1.3$\, M_{\odot }$ WD), gravitational energy of ejecta (39%; 52%), and kinetic energy of the wind (0.28%; 0.29%). We found an empirical relation for fast novae between the time to optical maximum from the outburst tpeak and the expansion timescale τexp. With this relation, we are able to predict the time to optical maximum tpeak from the ignition model (at t = 0) without following a time-consuming nova wind evolution.

Experimental investigation of the intensity and conditions for strainburst triggering in intact hard rocks

Strainburst occurs during deep hard rock excavations. A series of single-free-face true triaxial compression (TTC) tests were conducted on seven hard rock types to investigate strainburst intensity and triggering conditions. Five of the seven rock types failed by strainburst, and two failed by spalling. The differences between the strainburst intensities are attributed to the mineral composition and structure. High-hardness minerals and mosaic-type microstructures facilitate stress conduction, which promotes rock microcrack initiation and propagation, causing severe rock fragmentation and fragment ejection, as observed for the Jinzhou granite. However, if the proportions of high- and low-hardness rock minerals are high and the microstructure is stable, such as in the triangular microstructure of the Chifeng basalt, then microcrack initiation and propagation are inhibited, decreasing the likelihood of rock fragmentation. The triggering conditions for strainburst were further analysed by considering the source of kinetic energy. For intact rock specimens, the kinetic energy for rock fragment ejection mainly originates from the intrinsic potential energy (Wbk) released by the specimen itself; thus, strainburst triggering requires that the applied maximum principal stress exceeds the bearing capacity and that the rock Wbk exceeds zero. However, a high Wbk is needed to trigger strainburst for structural rock specimens. Based on these findings, the possibility of triggering strainburst during excavation is greater when the Wbk (>9.1 kJ/m3), rock quality designation (>75%), and in situ stress of the rock are all high.

Physical Correlations and Predictions Emerging from Modern Core-collapse Supernova Theory

In this paper, we derive correlations between core-collapse supernova observables and progenitor core structures that emerge from our suite of 20 state-of-the-art 3D core-collapse supernova simulations carried to late times. This is the largest such collection of 3D supernova models ever generated and allows one to witness and derive testable patterns that might otherwise be obscured when studying one or a few models in isolation. From this panoramic perspective, we have discovered correlations between explosion energy, neutron star gravitational birth masses, 56Ni and α-rich freezeout yields, and pulsar kicks and theoretically important correlations with the compactness parameter of progenitor structure. We find a correlation between explosion energy and progenitor mantle binding energy, suggesting that such explosions are self-regulating. We also find a testable correlation between explosion energy and measures of explosion asymmetry, such as the ejecta energy and mass dipoles. While the correlations between two observables are roughly independent of the progenitor zero-age main-sequence (ZAMS) mass, the many correlations we derive with compactness cannot unambiguously be tied to a particular progenitor ZAMS mass. This relationship depends on the compactness/ZAMS mass mapping associated with the massive star progenitor models employed. Therefore, our derived correlations between compactness and observables may be more robust than with ZAMS mass but can nevertheless be used in the future once massive star modeling has converged.

Experimental study on the effect of unloading rate on gneiss rockburst

Rockburst are often encountered in tunnel construction due to the complex geological conditions. To study the influence of unloading rate on rockburst, gneiss rockburst experiments were conducted under three groups of unloading rates. A high-speed photography system and acoustic emission (AE) system were used to monitor the entire process of rockburst process in real-time. The results show that the intensity of gneiss rockburst decreases with decrease of unloading rate, which is manifested as the reduction of AE energy and fragments ejection velocity. The mechanisms are proposed to explain this effect: (i) The reduction of unloading rate changes the crack propagation mechanism in the process of rockburst. This makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate, and more energy released in the form of shear crack propagation. Then, less strain energy is converted into kinetic energy of fragments ejection. (ii) Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate, resulting in the destruction of rockburst incubation process. The enlightenments of reducing the unloading rate for the project are also described quantitatively. The rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s, which was judged by the ejection velocity.

Relativistic shocks in conductive media

Context. Relativistic shocks are present in all high-energy astrophysical processes involving relativistic plasma outflows interacting with their ambient medium. While they are well understood in the context of relativistic hydrodynamics and ideal magnetohydrodynamics (MHD), there is a limited understanding of the properties related to their propagation in media characterized by finite electrical conductivity. Aims. This work presents a systematic method for the derivation and solution of the jump conditions for relativistic shocks propagating in MHD media with finite electrical conductivity. This method is applied to the numerical solution of the Riemann problem and the determination of the conditions inside the blastwave that is formed when ultrarelativistic magnetized ejecta interact with the circumburst medium during a gamma-ray burst. Methods. We derived the covariant relations expressing the jump conditions in a frame-independent manner. The resulting algebraic equations expressing the Rankine-Hugoniot conditions in the propagation medium’s frame were then solved numerically. A variable adiabatic index equation of state was used in order to obtain a realistic description of the post-shock fluid’s thermodynamics. This method was then employed for the solution of the Riemann problem for the case of a forward and a reverse shock, both of which form during the interaction of a gamma-ray burst ejecta with the circumburst medium. This allowed us to determine the kinematics of the resulting blastwave and the dynamical conditions in its interior. Results. Our solutions clearly depict the impact of the plasma’s electrical conductivity in the properties of the post-shock medium. Two characteristic regimes are identified with respect to the value of a dimensionless parameter that has a linear dependence on the conductivity. For small values of this parameter, the shock affects only the hydrodynamic properties of the propagation medium and leaves its electromagnetic field unaffected. No current layer forms in the shock front; thus, we refer to this as the current-free regime. For large values of this parameter, the ideal MHD regime has been retrieved. We also show that the assumption of a finite electrical conductivity can lead to higher efficiencies in the conversion of the ejecta energy into thermal energy of the blastwave through the reverse shock. The theory developed in this work can be applied to the construction of Riemann solvers for resistive relativistic MHD (RR4MHD).

Ionization of CH[formula omitted] under fast He-like Si-ion impact

We have studied the absolute double differential cross section (DDCS) of electrons ejected from the methane molecule (CH4) under the impact of highly charged fast projectile ions. The energy and angular distributions of electrons have been measured in interactions with 70 MeV Si12+ ions. These DDCS data together with the derived single differential cross sections and the total cross section (TCS) have been compared with predictions of the continuum distorted wave-eikonal initial state model using different approaches for the molecular orbitals. It has been found that the theories overestimate the measured DDCS values at low ejection energies, which may indicate shortcomings of the model in the case of strong perturbation. At the same time, applying the model to a previous measurement using fast C ions having a lower perturbation strength, excellent agreements have been obtained with the experimental data. Considering the scaling properties, the available TCS data have been plotted with a scaled parameter, namely the perturbation strength, q/v (where q= charge state, v=velocity of the projectile). The KLL Auger e-emission as well as the KLL hyper-satellite peaks are analyzed for different emission angles. The double K-vacancy production shows a considerable enhancement i.e. 37% of the single production cross section which is consistent with some of the recent experiments on K-ionization using x-ray techniques.

Experimental study on the transporting and crushing effect of gas on coal powder during the develop stage of coal and gas outburst in roadway.

In recent years, coal and gas outburst disasters are still occurring and difficult to prevent, seriously endangering the safety of coal mine production. It is well known that the transporting and crushing of outburst coal is the main pathway of energy dissipation during the coal and gas outburst process. However, a consensus regarding how much gas involves in outburst and affects energy dissipation is still lacking. Quantitative study on the gas effect on migration and fragmentation characteristics of outburst coal in restricted roadway space can improve the energy model and guide the prevention and control of gas outburst. In this paper, an improved visual coal and gas outburst dynamic effect simulation experiment system was used to conduct outburst simulation experiments at different gas pressure conditions. The results showed that the movement of outburst coal in the roadway has experienced various flow patterns. In the initial stage of the outburst, under low gas pressure condition, the motion of the outburst coal was dominated by stratified flow. However, as the gas pressure increases, the initial acceleration increases, and the outburst coal mainly move forward rapidly in the form of plug flow. The average velocity at 0.3, 0.5, and 0.8MPa gas pressure condition were 6.75, 22.22 and 35.81m/s, respectively. Gas also has a crushing effect on outburst coal. With increasing gas pressure, the number of coal powder particles of the same mass increased significantly, and the range of the particle size distribution of the particles decreaed, and the median particle size decreased. As the gas pressure increases, the outburst intensity gradually increases, and the total energy involved in the outburst work also increases. However, the energy dissipation pathways are different. At 0.3MPa, the energy dissipation is dominated by crushing energy, which is about six times the ejection energy. As the gas pressure increased to 0.8MPa, the proportion of the ejection energy gradually increases to about twice that of the crushing energy. Under the experimental conditions, 2.71-13.43% of the adsorbed gas involves in the outburst (AGIO) through rapid desorption, and the proportion increases with increasing gas pressure. This paper improves the energy model of coal and gas outburst, which is applicable to risk assessment and prevention of outburst disasters.

Experimental investigation and failure characteristics of slit-cut method in rockburst prevention

Rockburst has become one of the most serious threats to the safety of workers, equipment, and excavations in deep underground engineering. However, the prevention of rockburst risk remains an unsolved problem. The slot-cut method was put forward, aiming at the problem of strain burst for tunnel projects. The mechanism and method of slot-cut prevention of delayed rockburst were discussed by laboratory tests, theoretical analysis, and numerical simulation. The mechanical responses, failure patterns and failure indexes of granite specimens were analysed. The rockburst process and deformation evolution law of test specimens with different crack parameters were studied in great detail. Based on the experimental results, a comprehensive discrimination of rockburst proneness was explored. The results demonstrate that the peak stress and damage index of pre-cracked granite initially decreases and subsequently increases with crack angle, and the pre-peak and post-peak elastic modulus with different crack numbers decreases linearly, indicating that a change in the crack number significantly affects the bearing capacity of granite. The failure mode of the granite specimen belongs to the tension-shear composite type. Meanwhile, it was found that both the brittleness index and ejection energy with different cracks show an U-shaped for the pre-cracked granites, confirming that the crack angle of 60° has been found to be the threshold for rockburst proneness. Ultimately, the combination of the rockburst energy index describing rock ejection qualitatively and the optimized residual energy index considering elastic energy at post-peak stage quantitatively provides a judgment criteria to comprehensively characterize the rockburst proneness of granite by the slit-cut method. When compared with original index, the results of the comprehensive discrimination exhibited good accuracy. Therefore, the experimental phenomenon and judgment criteria prove that the slit-cut technology can be well applied to the rockburst prevention.

Intense solar activity reduces urinary 6-sulfatoxymelatonin in patients with COPD

BackgroundLittle is known about the link between solar activity and variations in melatonin. In this study, we investigated if melatonin's major urinary metabolite, urinary 6-sulfatoxymelatonin (aMT6s), is lowest under periods of intense solar activity.MethodsWe investigated associations between high-energy solar particle events [Coronal Mass Ejection (CME) mass, speed and energy] on creatinine-adjusted aMT6s (aMT6sr) concentrations in 140 patients with chronic obstructive pulmonary disease (COPD) using up to four seasonal urine samples (n = 440). Mixed effect models with a random intercept for each subject were used to estimate associations, including effect modification attributable to diabetes, obesity, and reduced pulmonary function.ResultsHigher values of CME were associated with reduced aMT6sr concentrations, with stronger associations in patients with diabetes. An interquartile range (IQR) increase in natural log CMEspeed averaged through two days before urine collection was associated with a reduction of 9.3% aMT6sr (95%CI: − 17.1%, − 0.8%) in aMT6sr. There was a greater reduction in aMT6sr in patients with diabetes (− 24.5%; 95%CI: − 35.9%, − 11.6%). In patients without diabetes there was no meaningful association (− 2.2%; 95%CI: − 12%, 8.4%). There were similar associations with CMEenergy and CMEmass. There was no effect modification attributable to reduced pulmonary function or obesity.ConclusionsThis is the first study in patients with COPD to demonstrate strong detrimental impact of high-energy solar particle events on aMT6sr, with greater associations in patients with diabetes. Since melatonin is an anti-oxidant, it is possible that adverse effects of intense solar activity may be attributable to a reduction in circulating melatonin and that patients with both COPD and diabetes may be more susceptible.

Light-curve modelling for the initial rising phase of rapidly evolving transients powered by continuous outflow

ABSTRACT A wind-driven model is a new framework to model observational properties of transients that are powered by continuous outflow from a central system. While it has been applied to fast blue optical transients (FBOTs), the applicability has been limited to post-peak behaviours due to the steady-state assumptions; non-steady-state physics, e.g. expanding outflow, is important to model the initial rising phase. In this paper, we construct a time-dependent wind-driven model, which can take into account the expanding outflow and the time evolution of the outflow rate. We apply the model to a sample of well-observed FBOTs. FBOTs require high outflow rates (∼30 M⊙ yr−1) and fast velocities (∼0.2–0.3c), with the typical ejecta mass and energy budget of ∼0.2 M⊙ and ∼1052 erg, respectively. The energetic outflow supports the idea that the central engine of FBOTs may be related to a relativistic object, e.g. a black hole. The initial photospheric temperature is 105 –106 K, which suggests that FBOTs will show ultraviolet (UV) or X-ray flash similar to supernova shock breakouts. We discuss future prospects of surveys and follow-up observations of FBOTs in the UV bands. FBOTs are brighter in the UV bands than in the optical bands, and the time-scale is a bit longer than that in optical wavelengths. We suggest that UV telescopes with a wide field of view can play a key role in discovering FBOTs and characterizing their natures.

Unified Relationship between Cold Plasma Ejections and Flare Energies Ranging from Solar Microflares to Giant Stellar Flares

We often find spectral signatures of chromospheric cold plasma ejections accompanied by flares in a wide range of spatial scales in the solar and stellar atmospheres. However, the relationship between physical quantities (such as mass, kinetic energy, and velocity) of cold ejecta and flare energy has not been investigated in a unified manner for the entire range of flare energies to date. This study analyzed the spectra of cold plasma ejections associated with small-scale flares and solar flares (energy 1025–1029 erg) to supply smaller energy samples. We performed Hα imaging spectroscopy observation by the Solar Dynamics Doppler Imager on the Solar Magnetic Activity Research Telescope. We determined the physical quantities of the ejecta by cloud model fitting to the Hα spectrum. We determined the flare energy by differential emission measure analysis using the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory for small-scale flares and by estimating the bolometric energy for large-scale flares. As a result, we found that the ejection mass M and the total flare energy E tot follow a relation of . We show that the scaling law derived from a simple physical model explains the solar and stellar observations with a coronal magnetic field strength as a free parameter. We also found that the kinetic energy and velocity of the ejecta correlate with the flare energy. These results suggest a common mechanism driven by magnetic fields to cause cold plasma ejections with flares on the Sun and stars.

Antiproton impact ionization of hydrogen atom: Differential cross sections computed by Coulomb wave function discrete variable representation method

Our aim is using the Coulomb wave function discrete variable representation method (CWDVR) for the calculation of collision problem in first time. Nonrelativistic collision of antiproton with hydrogen atom is described by solving the time-dependent Schrodinger equation numerically. Two collision amplitudes are used for calculation of the differential cross sections, one of them corresponds to impact parameter of the projectile while other one is determined by projectile momentum transfer and found by Fourier transform of the first one. The ionization amplitude calculated by projecting of the wave function onto continuum wave function of the ejected electron. The differential cross sections calculated depending on projectile impact energy, scattering angle and electron ejection energy and angles, which is a result that can be measured experimentally. Our results are in good agreement with the relativistic calculation results.

Quantitative energy storage and ejection release in superelastic shape memory alloy wire

Superelastic shape memory alloy (SMA) wire is a memorable deformation material with large resilience and high energy density. In this paper, a revolutionary and yet explainable property of the SMA is investigated and confirmed: superelastic SMA energy storage and release can be quantitatively measured using electrical resistance. This finding boosted the SMA with significant advantages and potential in the field of mechanical energy storage and ejection release. A state-of-the-art energy storage ejection device is designed to test the relationship among SMA wires' stress, strain, and electrical resistance. The resistance change rate, ejection energy density and energy conversion efficiency are studied in the SMA wire energy tests. The experimental results confirm that the resistance change rate of the superelastic SMA wire has a stable linear relationship with the strain. The ejection energy density increases with the resistance change rate. A theoretical model of the relationship between the ejection energy density and resistance change rate is established based on the experimental results. In conclusion, the superelastic SMA wire can achieve sophisticated tasks that require ‘programmable’ and predictable energy storage or ejection.

Interacting Kilonovae: Long-lasting Electromagnetic Counterparts to Binary Mergers in the Accretion Disks of Active Galactic Nuclei

We investigate the dynamics and electromagnetic (EM) signatures of neutron star–neutron star (NS–NS) or neutron star–black hole (NS–BH) merger ejecta that occur in the accretion disk of an active galactic nucleus (AGN). We find that the interaction between ejecta and disk gas leads to important effects on the dynamics and radiation. We show five stages of the ejecta dynamics: gravitational slowing down, coasting, Sedov–Taylor deceleration in the disk, reacceleration after the breakout from the disk surface, and momentum-conserved snowplow phase. Meanwhile, the radiation from the ejecta is so bright that its typical peak luminosity reaches a few times 1043–1044 erg s−1. Since most of the radiation energy has converted from the kinetic energy of merger ejecta, we call such an explosive phenomenon an interacting kilonova (IKN). It should be emphasized that IKNe are very promising, bright EM counterparts to NS–NS/BH–NS merger events in AGN disks. The bright peak luminosity and long rising time (i.e., 10 to 20 days in UV bands, 30 to 50 days in optical bands, and 100 days to hundreds of days in IR bands) allow most survey telescopes to have ample time to detect an IKN. However, the peak brightness, peak time, and evolution pattern of the light curve of an IKN are similar to a superluminous supernova in a galactic nucleus and a tidal disruption event making it difficult to distinguish between them. But it also suggests that IKNe might have been present in recorded AGN transients.

Triple-differential cross sections in three-dimensional kinematics for electron-impact-ionization dynamics of tetrahydrofuran at 250-eV projectile energy

We report a combined experimental and theoretical study of the ionization dynamics of tetrahydrofuran induced by 250 eV electron impact in which the highest occupied molecular orbital is ionized leading to the stable parent ion. Experimentally a reaction microscope was used, covering nearly the entire $4\ensuremath{\pi}$ solid angle for the ejected slow electron. We present the triple-differential cross sections for the projectile scattering angles of ${\ensuremath{\theta}}_{1}$ = $\ensuremath{-}{10}^{\ensuremath{\circ}}$ as a function of the emission angle of the ejected electrons with energies of ${E}_{2}=10$, 15, and 20 eV, i.e., for asymmetric energy sharing between the scattered and ejected electrons. The measured triple-differential cross sections are internormalized across the three ejected energies. The experimental data are compared with predictions from the molecular three-body distorted-wave (M3DW), the multicenter distorted-wave (MCDW) approaches, and a modified MCDW-WM method which includes the postcollision interaction using the Ward-Macek approximation. Generally, the M3DW cross sections show better agreement with experiment than the MCDW calculations except for the emission angles near the projectile forward direction. The MCDW and MCDW-WM calculations do not reproduce the recoil lobes and show very small intensity for the cross sections outside the scattering plane.

Cardiac Energy

Introduction/Objectives: In the cardiac cycle, should a coupling phase be considered between systole and diastole where cardiac suction occurs? Shouldn't the left ventricular ejection fraction be considered a poor reliability index? According to these considerations, would it not be more logical to speak of cardiac energy of suction and ejection as parameters that summarize the cardiac potential and to which variables that are not independent would concur. Materials and Methods: The concept of energy is incorporated by means of a detailed evaluation of the cardiac ability developed by both ventricles as a counterpart of ejection fraction values to assess ventricular function. The heart in its pump function, presents a dynamic effect that is greater than the volume it ejects. Data involving patients will have informed consent. Results: Understanding the active mechanism of the suction phase as a link between systole and diastole opens a wide scenario on surgical techniques and medical treatments for many cardiac diseases that are still the focus of attention. Conclusion: The important incorporation of other disciplines such as physics and hydraulics has allowed the evaluation of cardiac mechanics from pre-existing laws that denote and justify what the heart really represents: a mechanical suction pump. The understanding of cardiac functions is achieved from the cardiac structure-function and from a physico/hydraulic point of view.

Supernova 2009ip Outbursts in 2012: From Scenario to Model

Spherical and aspherical models are presented for two outbursts in 2012 of supernova 2009ip. Models are based on a scenario which suggests that the August 2012 outburst is caused by the explosive shell ejection from LBV-presupernova. The model predicts an emergence of an unobserved outburst in late July 2012 related to a shock breakout and a subsequent diffusive radiative cooling of the ejected envelope. The luminosity of the first observed outburst in August 2012 was presumably powered by the central source, whereas the second, more powerful outburst in late September 2012, was caused by the ejecta interaction with the circumstellar envelope. Models provide estimates of the ejecta energy and mass along with the mass of the circumstellar shell.

The Influence of Surface Binding Energy on Sputtering in Models of the Sodium Exosphere of Mercury

We have simulated the sodium (Na) exosphere of Mercury to show how the exosphere is affected by the assumed surface binding energy (SBE) of Na in the sputtered component. We constrained ion precipitation onto the surface using distributions for the cusp regions that are consistent with measurements by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging Fast Imaging Plasma Spectrometer instrument. We have simulated sputtering with SBEs of 0.27, 2.6, 4.4, and 7.9 eV, with the lowest value commonly used in exosphere models and the highest from recent molecular dynamics calculations for the Na-bearing feldspar end-member, albite. A gradual change in the exosphere is seen as the yield decreases and the ejecta energy increases with increasing SBE. We describe the corresponding exosphere source functions for ion sputtering (IS), as well as for the previously studied processes of micrometeoroid impact vaporization and photon-stimulated desorption (PSD), along with their release energy distributions and spatial distributions. We have summed the contributions of the various source processes to explain how and when the different sources can be distinguished by observations. The modeled exosphere scale heights range from 72 km for PSD to over 1000 km for IS using a SBE of 7.9 eV. We find that the processes responsible for generating Mercury's Na exosphere are separable by measuring line-of-sight column densities tangent to the planet at various altitudes and positions around the planet. Our initial results are consistent with the Na being sputtered from a high-SBE material such as feldspar, which has been predicted to be abundant on the Mercury's surface.

The effect of changing the shape factor on the efficiency of the flexible solar modules

This study investigates the performance of different shapes of the flexible photovoltaic modules. Three shapes of the flexible modules were compared under similar outdoor conditions: The standard flat, convex, and concave. The comparison was based on the solar radiation input, voltage output, current output, and back of the module’s temperature. Results showed that based on the output power and the efficiency for the modules, the standard flat module was of the highest performance, followed by the convex module and then by the concave module. The average output efficiency of the standard flat module was 4.5–6.0% and 0.8–1.2% for the convex module, while it was 0.46–0.53% for the concave module. In addition, a simulated energy analysis was carried out between the standard flat module toward the south direction and the convex module toward the southeast direction. The simulation results showed that an area that holds 50 standard flat modules, could hold 72 convex modules. Moreover, the annual ejected electrical energy into a grid for the standard flat modules and convex modules were 8.61 MWH and 5.462 MWH, respectively. Furthermore, the performance of the standard flat and convex modules were 74.79% and 70.96%, respectively.