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To solve some problems of celestial mechanics and astrophysics, three new models of an elliptical galaxy (EG) have been created, which are in good agreement with modern understanding of the structure of such galaxies. Based on these models, the total gravitational (potential) energy and rotational kinetic energy of an EG, as well as the velocity dispersion at a distance of its effective radius, are determined. A new method is proposed for determining the average values of the scale radius of an EG and the density at its center, as well as the average value of its key parameter density $\beta$ and its value at a distance corresponding to the effective radius of the galaxy. The results obtained are applied to sixty EGs and presented in the form of tables for ten galaxies., Comment: 22 pages, 4 tables

Space debris generally exhibit complex rotating motions, which cause significant challenges when attempting to capture them in orbit. Reducing the rotational speed of the space debris before capturing them with a high rotational energy can reduce the risk of destructive collisions. The electromagnetic de-tumbling method based on eddy currents has the advantages of being non-contact, pollution-free, and exhibiting no orbital height limitations, among other qualities. To improve the efficiency of electromagnetic de-tumbling, distributed high-temperature superconducting (HTS) coils are used in this study. Specifically, a finite element model is established to investigate the induced currents and eddy-current torque, and the optimal configuration of the distributed coils is obtained using numerical optimization. The analysis of the external magnetic field shows that if the distance between the target and the coils exceeds four times the radius of the target, the eddy-current torque and the magnetic field at the center of the target will achieve maximum values in the same configuration, and the external magnetic field can therefore be regarded as a uniform field when calculating the eddy-current torque. Finally, the finite element model and the optimal configuration are verified using simplified ground-based experiments.

The collapse of the magnetic rotating protostellar cloud with mass of $10\,M_{\odot}$ is numerically studied. The initial ratios of the thermal, magnetic, and rotational energies of the cloud to the modulus of its gravitational energy are 0.3, 0.2 and 0.01, respectively. The emphasis is on the evolution and properties of the quasi-magnetostatic primary disk formed at the isothermal stage of the collapse. Simulations show that the primary disk size and mass increase during evolution from $1500$ au to $7400$ au and from $0.3\,M_{\odot}$ to $5.2\,M_{\odot}$, respectively. Magnetic field is quasi-radial in the cloud envelope and quasi-uniform within the primary disk. A toroidal magnetic field is generated behind the front of the fast shock MHD wave propagating from the primary disk boundary and in the region of the outflow formed near the first hydrostatic core. The hierarchical structure of collapsing protostellar clouds can be revealed in observations in terms of the magnetic field geometry and the angular momentum distribution., 3 pages, 1 figure, published in Bulletin of the Lebedev Physics Institute

Models of boundary conditions on the surface of a body for rarefied molecular gas taking into account the rotational energy are investigated. A comparison of the temperature fields for the case of the flow past bodies is performed by the supersonic flow of a gas at incomplete energy accommodation on the surface and at various degrees of exchange of the rotational and translational energies. The influence of the intensity of exchange on the gas flow depending on the rarefaction parameter, the free-stream velocity, and the surface temperature is shown.

The rotation band is an important issue in the studies of nuclear structures, which offers a good laboratory for understanding of nuclear deformation, shell evolution, and other properties. Studies of nuclear collective rotations have mainly focused on open-shell nuclei in heavy-mass regions. Traditional collective models, such as the total Routhian surface and particle-rotor models, have been widely used. In principle, the phenomenological collective models are not suitable for the descriptions of rotations of light nuclei. The shell model with configuration interactions can describe any mass-region nuclei, as long as one chooses an appropriate model space. There have been recent studies of rotational bands of light nuclei within the shell model framework. The shell model calculation has shown a powerful model for the descriptions of low-lying states and shell evolutions. On the other hand, the shell model is a useful and popular method to analyze configurations of states. Recently, the L - S decomposition has been suggested for analyzing the collective properties of nuclei with shell-model calculation. In these light nuclei around the dripline, the intruded higher single-particle orbitals often occur in the ground states and mix with the normal single-particle orbitals. And a lot of work has been done to learn the exotic properties of the neutron-rich nuclei near 12Be. In the case of 12Be and its neighboring nuclei, it is believed that the strong configuration mixing of the intruder states and normal states leads to large deformations. And the rotational bands can build on the band-head states with large deformations. Therefore, an interesting question is whether rotational bands can exist in such light systems, and what the corresponding configurations are in the shell-model framework. In the present paper, using the WBP and YSOX interactions, we perform shell model calculations for the low-lying states of 10Be and 12Be, focusing on their excitation spectra. The rotational bands are constructed using the calculated B (E2) values and excitation energies. We give the rotational energy constants of these rotational bands. To further learn the properties of the states within the rotational band, we perform the L - S decomposition. The results show that the L - S decomposition can well describe the collective properties of the rotational band in 10Be and 12Be. In the calculations for 10Be, the WBP and YSOX interactions give similar results for L decomposition in J π= 0 2 + rotational band. But for 12Be, the WBP and YSOX interactions give different rotational intrinsic states, which show J π= 0 2 + for WBP and J π= 0 1 + for YSOX. Further discussions on shell model configurations for rotational bands are made as well. The results show that the above two rotational bands have strong intruders from the upper sd shell orbitals in the rotational states. For the ground state of 12Be, the WBP and YSOX interactions give different dominant configurations, which indicate that the intruder configuration from the sd shell in YSOX calculations is stronger. We discuss the possible origins of the difference, and future experimental studies for the rotational structure in 12Be should be expected.

Three pairs of signature partners' transition energies of Thallium (Tl) odd mass superdeformed (SD) nuclei's (A ~ 191-195), were fitted with the experimental one using the Bohr-Mottelson four-parameter collective rotational model. We chose the Bohr-Mottelson four-parameter rotational energy formula because it has been reported that it has excellent compatibility with the γ-ray transition energies. The four model parameters were extracted using a suitable search program. Harris's method was used to calculate the superdeformed rotational bands' (SDRBs) bandhead spins. The values of the adopted parameters, which were obtained using a simulated fitting search software, were used to measure the rotational frequency, dynamic J(2), and kinematic J(1) moments of inertia to the transition energies. When compared to the experimental values, there is a great deal of agreement J(2) and J(1) have been studied as a function of increasing rotational frequency. The suggested staggering function was used to investigate the ΔI= 1 energy staggering in Tl odd mass SD nuclei.

We describe the probabilistic physics of rarefied particle motions and deposition on rough hillslope surfaces. The particle energy balance involves gravitational heating with conversion of potential to kinetic energy, frictional cooling associated with particle–surface collisions, and an apparent heating associated with preferential deposition of low-energy particles. Deposition probabilistically occurs with frictional cooling in relation to the distribution of particle energy states whose spatial evolution is described by a Fokker–Planck equation. The Kirkby number Ki – defined as the ratio of gravitational heating to frictional cooling – sets the basic deposition behavior and the form of the probability distribution fr(r) of particle travel distances r, a generalized Pareto distribution. The shape and scale parameters of the distribution are well-defined mechanically. For isothermal conditions where frictional cooling matches gravitational heating plus the apparent heating due to deposition, the distribution fr(r) is exponential. With non-isothermal conditions and small Ki this distribution is bounded and represents rapid thermal collapse. With increasing Ki the distribution fr(r) becomes heavy-tailed and represents net particle heating. It may possess a finite mean and finite variance, or the mean and variance may be undefined with sufficiently large Ki. The formulation provides key elements of the entrainment forms of the particle flux and the Exner equation, and it clarifies the mechanisms of particle-size sorting on large talus and scree slopes. Namely, with conversion of translational to rotational kinetic energy, large spinning particles are less likely to be stopped by collisional friction than are small or angular particles for the same surface roughness.

Photoelectron-photofragment coincidence (PPC) measurements on OH-(C2H4) anions at a photon energy of 3.20 eV revealed stable and dissociative photodetachment product channels, OH-C2H4 + e- and OH + C2H4 + e-, respectively. The main product channel observed was dissociation to the reactants (>67%), OH + C2H4 (v = 0, 1, 2) + e-, where vibrational excitation in the C-H stretching modes of the C2H4 photofragments corresponds to a minor channel. The low kinetic energy release (KER) of the dissociating fragments is consistent with weak repulsion between the OH + C2H4 reactants near the transition state as well as the partitioning of energy into rotation of the dissociation products. An impulsive model was used to account for rotational energy partitioning in the dissociative photodetachment (DPD) process and showed good agreement with the experimental results. The low KER of the dissociating fragments and the similarities in the photoelectron spectra between stable and dissociative events support a mechanism involving the van der Waals complex formed upon photodetachment of OH-(C2H4) as an intermediate in the dominant OH + C2H4 + e- dissociative channel.

Summary Advances in wireless sensors, biomedical devices, and micro-robotics exert more pressure on creating reliable, miniaturized, and self-sustained energy supply solutions for these micro-electromechanical systems. Rotational energy harvesting (REH) is one of the rapidly growing areas for self-powered electronics using available rotational energy or energy converted from other sources in the environment. This paper comprehensively reviews the state-of-the-art progress in REH in terms of the available energy characteristics, harvester categories, adopted methodologies and mechanisms, and promising applications. Unique mechanisms and methodologies, such as using gravity and centrifugal force combined with other nonlinear mechanisms, are discussed and characterized. In terms of applications, wearable and implantable devices, automotive, rotating machines, renewable energy systems, and environmental sensing are discussed and reviewed to illustrate how rotational energy harvesters have been developed and adopted accordingly. Based on progress to date, the key developments, critical challenges, and issues are summarized and discussed. Moving forward, an outlook is presented to outline potential research directions and opportunities in this area.

A novel concept for the deflection of rotating asteroids is presented, based on the conversion of the asteroid rotational kinetic energy into translational kinetic energy. Such conversion is achieved using an orbital siphon, a tether-connected chain of masses, arranged vertically from the asteroid surface, which exploits the rotation of the asteroid for the delivery of mass from the asteroid to escape. Under the conditions to be discussed, the siphon can be initiated to ensure self-sustained flow of mass from the asteroid to escape. This mechanism is proposed to use a fraction of the asteroid as reaction mass, with the asteroid rotational kinetic energy leveraged to deliver the mass to escape and hence impart a reaction on the asteroid itself. Key parameters, such as velocity change, deflection duration, tension requirements and siphon length, are discussed. Deflection effectiveness is assessed for different release strategies. It is shown that typical velocity changes on the order of 1 cm/s can be achieved within a time window of a decade.

Our primary goal was to measure the NO (A) photoproduct appearance energy and ground-state dissociation energy of the N2-NO complex. We recorded velocity map ion images of NO photofragments resulting from the dissociation of the N2-NO complex excited between ∼225.8 and 224.0 nm, which ranged from the photodissociation threshold to about 342 cm-1 above the threshold. In the experiment, one photon dissociated the complex through the N2 (X 1Σg+)-NO (A 2Σ+) ← N2 (X 1Σg+)-NO (X 2Π) transition, and a second photon nonresonantly ionized the NO (A) photoproduct. The lowest-energy photons near 225.8 nm did not have sufficient energy to photodissociate the lowest excited state of the complex; however, dissociation was observed with increasing photon energy. On the basis of the experiments, we determined the appearance energy for the NO (A) photoproduct to be 44 284.7 ± 2.8 cm-1. From the appearance energy and the NO A ← X origin band transition, we determined a ground-state dissociation energy of 85.8 ± 2.8 cm-1. As we increased the photon energy, the excess energy was partitioned into rotational modes of the diatomic products as well as product translational energy. We found good agreement between the average fraction of rotational energy and the predictions of a simple pseudo three atom impulsive model. Finally, at all photon energies, we observed some contribution from internally excited complexes in the resulting P(ET). The maximum internal energy of these complexes was consistent with the ground-state dissociation energy.

Tire pressure monitoring system (TPMS) has been brought into the stringent regulatory frameworks of many countries in the automotive market. However, common commercial TPMSs must rely on a life-limited battery, which brings about some safety risks and environmental problems. It is worthy to note that energy harvesting approaches are promising to realize a batteryless TPMS. In this article, a rotation-driven piezoelectric energy harvester with eight typical nonlinear buckled bridges is proposed to effectively scavenge ultralow frequency kinetic energy. Thinned bulk PZT film is employed as the piezoelectric functional layer based on its excellent electromechanical factor. Gear-induced interwell oscillation mechanism ensures the effective deformation of the piezoelectric buckled bridges. The developed harvester can generate the effective output power of 8.9 mW under the optimal resistance of 3 kΩ at 8.3 Hz rotational frequency. The 47, 100, and 330 μF capacitors can be saturated at 14.5, 15.1, and 14.5 V during 10, 19, and 51 s, respectively. Additionally, a commercial TPMS can be effectively powered by this harvester when it works at more than a critical frequency locating at 3.0–3.7 Hz. The commercial TPMS can be operated in realtime when the applied rotational frequency is more than 8.3 Hz.

Recent work has called into question whether nature can extract the rotational energy of a black hole via electromagnetic fields by appealing to an alleged ability to absorb current. We describe the strategies needed to properly treat the astrophysics in curved spacetime near black holes, showing that while the Blandford-Znajek effect is sound, the deeper nature of the electric nature of black holes remains unresolved., 7 pages, Post-peer-review, pre-copyedit version of an article published in Nature Astronomy

This paper has been explained to study the rotational arrangement of even-even 168Hf isotope using the phenomenological fitting, Sood’s semi-empirical formula. The rotational energies from the calculated values were compared to the experimental data. The result shows that in 168Hf, calculated energies fit the experimental values to a remarkable degree of accuracy.

Three-dimensional conformation is the primary determinant of molecular properties. The thermal energy available at room temperature typically equilibrates the accessible conformational states. Here, we introduce a method for isolating unique and previously understudied conformations of macrocycles. The observation of unusual conformations of 16- to 22-membered rings has been made possible by controlling their interconversion using dominant rotors, which represent tunable atropisomeric constituents with relatively high rotational barriers. Density functional theory and in situ NMR measurements suggest that dominant rotor candidates for the amino-acid-based structures considered here should possess a rotational energy barrier of at least 25 kcal mol−1. Notable differences in the geometries of the macrocycle conformations were identified by NMR spectroscopy and X-ray crystallography. There is evidence that amino acid residues can be forced into rare turn motifs not observed in the corresponding linear counterparts and homodetic rings. These findings should unlock new avenues for studying the conformation–activity relationships of bioactive molecules. Constrained molecules typically adopt one major conformation and this limitation prevents the study of other energetically less-favourable conformations. Nevertheless, these alternate structures might prove to be useful and it has now been shown that a dominant rotor method can alter the energetic landscape of peptides to create two-well systems with distinct conformational behaviour.

A unique spectroscopic strategy has been developed for laser absorption sensing of carbon monoxide (CO) and carbon dioxide (CO2) at extreme pressures (P > 50 atm) relevant to modern combustion devices. The strategy exploits the band narrowing effects of line mixing, which acutely impact spectrally dense regions, such as bandheads, where line spacing is small. Line mixing is shown to counter collisional line-broadening effects that reduce differential absorption at elevated pressures and often limit the pressure range of laser absorption methods. In this work, the R-branch bandheads of CO and CO2, which are only observed at high temperatures relevant to combustion, are targeted near 2.3 µm and 4.2 µm, respectively. Spectral line-mixing models were developed for each bandhead region to account for the collision-induced population transfer rates between rotational energy states over a wide range of elevated temperatures and pressures. Modified-exponential-gap models using the relaxation matrix formalism were shown to capture the thermodynamic dependence of the population transfer rates and enabled scaling. Differential absorption at the bandheads was observed to increase by up to a factor of ten at high gas densities, due to line-mixing effects, enabling detection with relatively narrow-band tunable semi-conductor lasers. With refined spectroscopic models, laser absorption measurements of temperature, CO, and CO2 were demonstrated over a range of high pressures (up to 104 atm) in a sub-scale rocket combustor operated with kerosene and supercritical methane.

The direct three-body recombination reactions Cs+ + X− + R → CsX + R (X = F, I and R = Ar, Xe) are studied within the quasiclassical trajectory method using diabatic semiempirical potential energy surfaces, the encounters of the ions being non-central. The collision energies range between 1 and 10 eV (values typical for low temperature plasma), while the so-called delay parameter, which characterizes the delay in the arrival of the neutral atom R in relation to the time instant when the distance between the ions attains its minimum, is equal to 0 or 20%. The calculation results include the recombination excitation functions, the opacity functions, and the vibrational and rotational energy distributions of the recombination products. All the four reactions considered exhibit similar overall statistical dynamics, but each process has its own features. On the whole, for both the recombining pairs Cs+ + F− and Cs+ + I−, xenon is more effective than argon as an acceptor of excess energy from the ion pair. The rotational energy distributions of the salt molecules CsF and CsI are almost equilibrium, whereas the vibrational energy distributions are strongly non-equilibrium.

HighlightsThe relationship between the angle of repose and compound fertilizer particle size distribution and sphericity was revealed.The range of the rolling friction coefficient obtained by different modeling was calibrated by the golden section method.Scanning modeling required 80% of the rolling friction coefficient of spherical modeling to reflect actual motion.The relative error of scanning modeling (7.91%) was better than that of spherical modeling (30.84%).Abstract. The discrete element method (DEM) is widely used to simulate the behavior of granular materials. The accurate establishment of the particle model has a great influence on the accuracy of the simulation. Most of the existing discrete element simulations of granular compound fertilizers use spherical modeling without considering the shape or particle size distribution. To compare the simulation accuracy of spherical modeling (spherical particles with equivalent diameters) and scanning modeling (a three-dimensional model of fertilizers was obtained by a scanner and then automatically filled by EDEM2020 software) on compound fertilizer discharge, three kinds of granular compound fertilizers (Changqingshu, Xinshidai, and Munvhong) were selected as the research objects. The characterization parameters of fertilizer shape and fluidity were measured. Principal component analysis and Pearson correlation analysis were used to analyze the influence of the compound fertilizer characterization parameters on the angle of repose. The results showed that the particle shape and particle size distribution of compound fertilizer were the main factors affecting its angle of repose. Through the golden section method and a single-factor experiment, the rolling friction coefficients of the three granular fertilizers under the two granular modeling methods for spherical modeling and scanning modeling were determined. The results showed that the rolling friction coefficient when using scanning modeling to approximate the actual angle of repose was approximately 80% of that when using the spherical modeling method. The influence of different modeling methods on the total rotational kinetic energy and the formation of the angle of repose was discussed. For the same fertilizer, the total rotational kinetic energy was greater in spherical modeling than in scanning modeling, and the formation time of the angle of repose was longer in scanning modeling than in spherical modeling. The results of an external tank wheel fertilization simulation and bench test showed that considering the scanning modeling of fertilizer shape and particle size distribution, the fertilization variation coefficient obtained from the simulation test was closer to that of the bench test. This research helps to better understand the influence of particle shape and particle size distribution on DEM simulations and provides references for discrete element modeling of other granular fertilizers. Keywords: Compound fertilizer, Modeling method, Shape, Simulated flow characteristics, Size distribution.

The rate coefficients of rotationally inelastic collision processes for N2-HF as well as N2-DF systems were calculated by applying the recently developed coupled-states approximation including the nearest neighbor Coriolis couplings approach, based on the full-dimensional ab initio intermolecular potential energy surface. It was found that the energy gap law governs these energy transfer processes. For rotational quenching of N2 (j1 = 2-10) by the ground rotational state of HF, j1 = 6 and 5 have the maximum quenching rate for ortho-N2 and para-N2, respectively. Quenching rate coefficients for initially excited HF and DF (j2 = 1) in collisions with N2 were also reported, where N2-DF has a larger quenching rate than N2-HF due to larger density of states of the N2-DF system.

Glycinamide is considered to be one of the possible precursors of the simplest amino acid glycine. Its only rotational spectrum reported so far has been in the cm-wave region. The aim of this work is to extend its laboratory spectrum into the mm wave region to support its searches in the ISM. Glycinamide was synthesised chemically and was studied with broadband rotational spectroscopy in the 90-329 GHz region. Tunneling across a low energy barrier between two symmetry equivalent configurations of the molecule resulted in splitting of each vibrational state and many perturbations in associated rotational energy levels, requiring careful coupled state fits for each vibrational doublet. We searched for emission of glycinamide in the imaging spectral line survey ReMoCA performed with ALMA toward Sgr B2(N). We report the first analysis of the mm-wave rotational spectrum of glycinamide, resulting in fitting to experimental measurement accuracy of over 1200 transition frequencies for the ground state tunneling doublet, of many lines for tunneling doublets for two singly excited vibrational states, and determination of precise vibrational separation in each doublet. We did not detect emission from glycinamide in the hot core Sgr B2(N1S). We found that glycinamide is at least seven times less abundant than aminoacetonitrile and 1.8 times less abundant than urea in this source. A comparison with results of astrochemical kinetics models for species related to glycinamide suggests that its abundance may be at least one order of magnitude below the upper limit obtained toward Sgr B2(N1S). This means that glycinamide emission in this source likely lies well below the spectral confusion limit in the frequency range covered by the ReMoCA survey. Targetting sources with a lower level of spectral confusion, such as the Galactic Center shocked region G+0.693-0.027, may be a promising avenue. [abridged], Accepted for publication in A&A