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The insight that optical vortex beams carry orbital angular momentum (OAM), which emerged in Leiden about 30 years ago, has since led to an ever expanding range of applications and follow-up studies. This paper starts with a short personal account of how these concepts arose. This is followed by a description of some recent ideas where the coupling of transverse orbital and spin angular momentum (SAM) in tightly focused laser beams produces interesting new effects. The deflection of a focused light beam by an atom in the focus is reminiscent of the Magnus effect known from aerodynamics. Momentum conservation dictates an accompanying light force on the atom, transverse to the optical axis. As a consequence, an atom held in an optical tweezer will be trapped at a small distance of up to $\lambda/2\pi$ away from the optical axis, which depends on the spin state of the atom and the magnetic field direction. This opens up new avenues to control the state of motion of atoms in optical tweezers as well as potential applications in quantum gates and interferometry., Comment: revised version; 15 pages, 4 figures

The current article is concerned with a nonlinear stability analysis of cylindrical Walters B' fluids. The system is pervaded by an axial time periodic electric field. A cylindrical interface is supposed to be disconnected from two dielectric fluids. The fluids are fully saturated in porous media. The motivation to scrutinize this area is attributed to the great attention it receives in many practical situations in physics and engineering applications. The implementation of the appropriate nonlinear boundary conditions of the linearized equations of motion yields a nonlinear characteristic dispersion equation. This equation manages the surface deflection of the surface waves. The use of the non-dimensional analysis resulted in various well-known non-dimensional numbers. A new approach to the characteristic equation is inspected by employing the Homotopy perturbation method (HPM). This new methodology resulted in a Klein-Gordon equation. Utilizing a travelling-wave solution to the linear part of the characteristic equation, a new restriction of the stability analysis appears. The investigation reveals the non-resonance as well as the resonance cases, and the stability criteria are established in both arguments. A set of diagrams is plotted to display the influence of various non-dimensional physical numbers on the stability profile and shows interesting features.

The deflection of charged particles is an intuitive way to visualize an electromagnetic oscillation of coherent light. Here, we present a real-time ultrafast oscilloscope for time-frozen visualization of a terahertz (THz) optical wave by probing light-driven motion of relativistic electrons. We found the unique condition of subwavelength metal slit waveguide for preserving the distortion-free optical waveform during its propagation. Momentary stamping of the wave, transversely travelling inside a metal slit, on an ultrashort wide electron bunch enables the single-shot recording of an ultrafast optical waveform. As a proof-of-concept experiment, we successfully demonstrated to capture the entire field oscillation of a THz pulse with a sampling rate of 75.7 TS/s. Owing to the use of transversely-wide and longitudinally-short electron bunch and transversely travelling wave, the proposed “single-shot oscilloscope” will open up new avenue for developing the real-time petahertz (PHz) metrology., A travelling wave inside a metal slit can reveal its own waveform by probing deflecting motions of charged particles. Here, a real-time THz oscilloscope was demonstrated by utilizing the relativistic electrons and the subwavelength slit waveguide.

Free-space transmission of terahertz waves open great opportunities for wireless communication and sensing in the Beyond 5G/6G paradigm. Nevertheless, terahertz transmission suffers from severe diffraction losses due to the shorter wavelengths than the microwaves. To compensate for the diffraction losses, point-to-point transmission by directional beams is indispensable. However, implementing terahertz beam steering is still challenging due mainly to the lack of practical phase shifters. To circumvent this challenge, we demonstrate a novel strategy of two-dimensional (2-D) terahertz beam steering based on trajectory deflection of leaky-mode at around 300 GHz. We use a pair of metal plates with a mesh surface, in which the phase velocity exceeds the light speed in free-space. The leaky-mode can be steered vertically by a phase matching condition controllable with frequency sweep and horizontally by graded refractive index controllable with small tilt of the plate. The result confirms 2-D beam steering without relying on phase shifters.

Recent studies have shown that minimal couplings for massive spinning particles, which in the classical limit reproduce the leading PM Kerr black hole dynamics, leads to an Eikonal S-matrix exhibiting spin-entanglement suppression. In this paper we trace this phenomenon to the suppression of spin-flipping components in the S-matrix, known to be the hallmark of minimal coupling in the ultra-relativistic limit. We further generalize the consideration to charged and $\mathcal{N}=4$ black holes, demonstrating that in both cases maximal suppression occurs at the extremal limit., Comment: 28 pages, 6 figures, 1 ancillary file

The Rare Isotope Science Project was launched in 2011 in Korea toward constructing the Rare isotope Accelerator complex for ON line experiments (RAON). RAON will house several experimental systems, including the Muon Spin Rotation/Relaxation/Resonance (μSR) facility in High Energy Experimental Building B. This facility will use 600-MeV protons with a maximum current of 660 pμA and beam power of 400 kW. The key μSR features will facilitate projects related to condensed-matter and nuclear physics. Typical experiments require a few million surface muons fully spin-polarized opposite to their momentum for application to small samples. Here, we describe the design of a muon transport beam line for delivering the requisite muon numbers and the electromagnetic-component specifications in the μSR facility. We determine the beam-line configuration via beam-optics calculations and the transmission efficiency via single-particle tracking simulations. The electromagnet properties, including fringe field effects, are applied for each component in the calculations. The designed surface-muon beamline is 17.3 m long, consisting of 2 solenoids, 2 dipoles affording 70° deflection, 9 quadrupoles, and a Wien filter to eliminate contaminant positrons. The average incident-muon flux and spin rotation angle are estimated as 5.2 × 106 μ+/s and 45°, respectively.

A new model of a first-order composite beam with flexoelectric and piezomagnetic layers is developed. The new model is under a transverse magnetic field and can capture the couple stress and its flexoelectric effects. The governing equations are obtained through a variational approach. To illustrate the new model, the static bending problem is analytically solved based on a Navier’s technique. The numerical results reveal that the extension, deflection, and shear deformation of the current or couple stress relevant flexoelectric model are always smaller than those of classical models at very small scale. It is also found that the electric potentials only appear with the presence of the flexoelectric effect for this non-piezoelectric composite beam model. Furthermore, various electric potential distributions can be manipulated by the particular magnetic fields, and remote/non-contact control at micro- and nano-scales can be realized by current functional composite beams.

Multi-target X-ray tube is a new type X-ray source, and can be applied in many fields such as sensitive X-ray fluorescence analysis and medical imaging. In this work, we report an electric field modulation multi-target X-ray tube, which contains four targets (Cr, Ni, Au, Mo) coated on a Beryllium (Be) window. A four-valve electric field deflector was developed to deflect the electron beam to bombard the corresponding targets. Particle dynamics analysis software was employed to simulate the particle tracking of electron beam. The results show that the 30 keV electron beam could get a 6.7 mm displacement on the target plane by 105 V/m electric field. The focus areas are about 2 mm × 5 mm and 4 mm × 2.5 mm after deflection in two directions. Thermal behavior calculated by ANSYS shows that the designed target assembly could withstand a 10 W continuous power. The optimum target thicknesses and emission spectra were obtained by Geant4 when the thickness of Be window was 300 μm and the electron beam incident angle was 0.141 rad. The results indicate that this multi-target X-ray tube could provide different X-ray sources effectively.

Dust accumulation is one of the reasons for the performance degradation of concentrating photovoltaic and thermal (CPV/T) systems due to the deposition of dust particles with different compositions, shapes, sizes, and masses. In this work, an optical model was developed to investigate the influence of the particle size, diameter, shape, and deposition density on the light concentration efficiency, using the Monte Carlo raytracing (MCRT) method in the Tracepro software. The triangular particles had a larger influence on the light ray deflection and energy flux degradation than the circular and square particles. An average increase in the dust density of 1 g/m2 decreased the light concentration efficiency of particles with sizes smaller than 50 µm and 60 µm by 3.31% and 3.26%, respectively. Furthermore, the effect of the incidence angle on the light concentration efficiency was considered at an angle less than 2°.

In the current paper we analyse the three classical tests of general relativity, namely, the precession of perihelion, deflection of light, and time delay in Einstein–æther gravity. Einstein–æther gravity has two static, spherically symmetric, charged black hole solutions corresponding to different constraints on its coupling constants c14 and c123. We investigate the aforementioned tests for both these solutions, graphically and analytically. We also tabulate our results and discuss the outcome, which is promising. We evaluate the results, when the coupling constants are varied over a vast range of values, both within the constraints set by the recent observational data, and also beyond, for a comparative study.

The purpose of this paper is to establish an existence and uniqueness theorem for the nonlocal fourth-order nonlinear beam differential equations with a parameter $ \begin{equation*} u^{(4)}+A(x)u = \lambda f (x, \ u, \ u''), \ 0 subject to the integral boundary conditions: $ \begin{equation*} u(0) = u(1) = \int_{0}^{1}p(x)u(x)dx, \ u''(0) = u''(1) = \int_{0}^{1}q(x)u''(x)dx, \end{equation*} $ where $ A\in \mathbb{C}[0, 1], $ $ \lambda > 0 $ is a parameter and $ p, q \in \mathbb{L}^{1}[0, 1]. $

The ability of cells to convert mechanical perturbations into biochemical information is an essential aspect of mammalian physiology. The molecules that mediate such mechanotransduction include mechanically activated ion channels, which directly convert mechanical inputs into electrochemical signals. The unifying feature of these channels is that their open probability increases with the application of a mechanical input. However, the structure, activation profile and sensitivity of distinct mechanically activated ion channels vary from channel to channel. In this review, we discuss how ionic currents can be mechanically evoked and monitored in vitro, and describe the distinct activation profiles displayed by a range of mammalian channels. In addition, we discuss the various mechanisms by which the best-characterized mammalian, mechanically activated ion channel, PIEZO1, can be modulated. The diversity of activation and modulation of these mammalian ion channels suggest that these molecules may facilitate a finely controlled and diverse ability to sense mechanical inputs in mammalian cells.

In the future, a hazardous asteroid will find itself on a collision course with Earth. For asteroids of moderate size or larger, a nuclear device is one of humanity’s only technologies capable of mitigating this threat via deflection on a timescale of less than a decade. This work examined how the output neutron energy from a nuclear device standoff detonation affects the deflection of a notional asteroid that is 300 meters in diameter and composed of silicon dioxide at a bulk density of 1.855 g/cm 3 . 14.1 MeV and 1 MeV neutron energy sources were modeled in MCNP to quantify the energy deposition in the asteroid target. The asteroid’s irradiated region was discretized in angle by tracing the rays emanating from the point of detonation and in depth by considering the neutron mean-free-paths. This high-fidelity approach was shown to deviate from previous analytic approximations commonly used for asteroid energy deposition. 50 kt and 1 Mt neutron yields of the energy deposition mappings were imported into a hydrodynamic asteroid model in ALE3D to simulate the deflective response due to blow-off ejecta. Underexplored in literature, changing the neutron energy was found to have up to a 70% impact on deflection performance due to induced differences in the energy deposition profile and in the energy coupling efficiency. The magnitude of energy deposition accounted for most of the observed variation in the asteroid velocity change, making the coupling efficiency more significant than the spatial profile characteristics. These findings are vital for determining the optimal source neutron energy spectrum for asteroid deflection applications.

Photo-induced deflection of circular glassy nematic discs with different spiral director fields is studied by extending the Foppl–von Karman plate theory, and the objective is to examine the effects of director distribution and photo-attenuation across the thickness. The analytical solutions are obtained for axisymmetric deformations via the perturbation technique, and the predicted disc shapes are in qualitative consistency with some existing experimental observations. The analysis indicates that the photo-attenuation breaks up–down symmetry of deformation, causing the disc to bend out of plane in a definite direction without an intensity threshold of the incidental light. In addition, it is shown that the deflection can be maximized by optimizing the ratio of the disc thickness to the characteristic length of light attenuation. These results are expected helpful to the design of photo-activated glassy nematic devices.

As the key component for the Higgs operating mode of Circular Electron–Positron Collider (CEPC), the electrostatic–magnetic deflectors are required by the double ring collider to separate the electron and the positron beams horizontally in the RF regions. The electric field is required to reach 2 MV/m with the vacuum pressure of less than 2 × 10−10 Torr. The deflectors make use of both electric and magnetic fields to deflect the beams. The incoming beam gets zero deflection, but the outgoing beam is deflected by the combined effect of the electric and magnetic forces. W and Z modes use the same cavities with H mode to save budget. The deflectors are large contributors to the overall beam impedance which is necessary to be reduced as much as possible. The electric and magnetic field optimization has been performed by the Opera. The beam impedance study has been carried out using the Computer Simulation Technology (CST) particle studio. The shape of the electrode is optimized for a good electric field homogeneity (± 0.05%) in 46 mm × 40 mm region. The electric field and the magnetic field could be matched perfectly in the main body of the deflector by bending the electrodes and introducing magnetic field clamps and mirror plates. The beam loss factor decreases by about 20% via the introduction of ground electrodes and tapering ends. The design results successfully meet the physical requirements, and the mechanical design has been finished.

The ability to deflect dangerous small bodies in the Solar System or redirect profitable ones is a necessary and worthwhile challenge. One well-studied method to accomplish this is laser ablation, where solid surface material sublimates, and the escaping gas creates a momentum exchange. Alternatively, laser-induced spallation and sputtering could be a more efficient means of deflection, yet little research has studied these processes in detail. We used a 15-kW Ytterbium fiber laser on samples of olivine, pyroxene, and serpentine (minerals commonly found on asteroids) to induce spallation. We observed the process with a high-speed camera and illumination laser, and used X-ray micro-tomography to measure the size of the holes produced by the laser to determine material removal efficiency. We found that pyroxene will spallate at power densities between 1.5 and 6.0 kW cm−2, serpentine will also spallate at 13.7 kW cm−2, but olivine does not spallate at 1.5 kW cm−2 and higher power densities melt the sample. Laser-induced spallation of pyroxene and serpentine can be two- to three-times more energy efficient (volume removed per unit of absorbed energy) than laser-induced spattering, and over 40x more efficient than laser ablation. Validerad;2021;Nivå 2;2021-03-02 (johcin)

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.

Visible plumes above wet cooling towers are of great concern due to the associated aesthetic and environmental impacts. The parallel path wet/dry cooling tower is one of the most commonly used approaches for plume abatement, however, the associated capital cost is usually high due to the addition of the dry coils. Recently, passive technologies, which make use of free solar energy or the latent heat of the hot, moist air rising through the cooling tower fill, have been proposed to minimize or abate the visible plume and/or conserve water. In this review, we contrast established versus novel technologies and give a perspective on the relative merits and demerits of each. Of course, no assessment of the severity of a visible plume can be made without first understanding its atmospheric trajectory. To this end, numerous attempts, being either theoretical or numerical or experimental, have been proposed to predict plume behavior in atmospheres that are either uniform versus density-stratified or still versus windy (whether highly-turbulent or not). Problems of particular interests are plume rise/deflection, condensation and drift deposition, the latter consideration being a concern of public health due to the possible transport and spread of Legionella bacteria.

Aesthetic is main sort of poetry, during the history the poems have focused on it and in term of concrete this they have tried a lot. Some of the detractors to evaluate the poetry texts they concrete the aesthetic. ‌ in this aspect our paper (Deflected aesthetics in the poetry of general love Muhammed Kurdo) it will attempt to illustrate those language deflected that have been concreted in his poetries. ‌ the research consists of three pivots. The first pivot (poetry´s deflected aesthetic) in general, it describes the concept of aesthetic, poetry, language, deflection and their relation to the construction of text aesthetic. The second pivot (heading aesthetic) this part describe the title aesthetic that have been concreted thru deflect. The third pivot (language deflected aesthetic) language deflected and those aesthetic dimensions in the texts have been described. ‌the result demonstrated in some points with the references.

This paper is to quantify the external wind effects on flame behavior evolutions inside and outside a compartment with opposing openings. Temperature profiles at the windward and leeward corners inside the compartment as well as the external flame trajectories were investigated. Experimental results show that the flame shape inside the compartment changes from the windward symmetrical rotation flame to the leeward deflection flame, as the heat release rate increases or the external wind velocity decreases. It results from the competition between the buoyancy force of fire plume and the wind-driven flow field. Two external flame shapes, the horizontally ejected fire and spill-like plume, take place in sequence with decreasing wind velocity. The trajectory of horizontally ejected fire is perpendicular to the building facade. By validating coordinate values of trajectory databases for the spill-like plume, prediction correlations for the trajectory are developed with a notion of the physical process.

A planetary model simulating the Sun, Venus, and Earth is constructed with the possibility of “Venus” to render a gravity assist to a ballistic space probe sent from the Earth's orbit. Thorough analytical and numerical analysis shows that a shift of the probe's impact parameter (IP) entails a noticeable deflection of the probe at the final point back on the Earth's orbit. For a relatively short IP, the “Venus-GA” acts as a powerful amplifier (up to 105 times), making it possible to detect changes in the probe's IP that are caused by different physical reasons. This finding prompted Solar system experiments to measure very small physical effects, e.g., to check the actuality of gravity theories.

In this study, a parametric amplification model of a vibrating beam micro-gyroscope is established with the effects of size-dependent and fringing field taken into account. Compared with conventional electrostatic beam gyroscopes, piezoelectric films are added to the four surfaces of the rectangular beam of vibrating micro-gyroscopes. Due to piezoelectric effect, the beam will be subjected to an axial excitation, which provides parametric amplification to enlarge the transverse vibration and to enhance the sensitivity. The effects of the size-dependent, fringing field and piezoelectric voltages on static deflection, eigenvalue analysis and dynamic amplification of the vibrating beam micro-gyroscopes are investigated. The influence of damping on the stability analysis of the gyroscopic system is also studied. When the frequency of parametric excitation is twice the natural frequency of the system, it is found that higher piezoelectric AC voltage amplitudes within the stable region are given in both sense and drive directions, which may generate a better sensitivity of the vibrating beam micro-gyroscope.

One of the three consequences of Einstein’s theory of general relativity was the curvature of light passing near a massive body. In 1911, he published a first value of the angle of deflection of light, then a second value in 1915, equal twice the first. In the early 1920s, when he received the Nobel Prize in Physics, a violent controversy broke out over this result. It was then disclosed that the first value he had obtained in 1911 had been calculated more than a century before by a German astronomer named Johann von Soldner. The aim of this article is therefore to compare the methods used by Soldner and then by Einstein leading to this first value and to explain the importance of the doubling of this value in the framework of Einstein’s theory of general relativity. Such a consequence of this theory lies at the intersection of several scientific fields such as Mathematics, Physics, Astronomy and Philosophy.

The present study is concerned with the analysis of the existence of magnetic field in micro-beam resonators in the context of generalized thermoelasticity with single relaxation time. MEMS are mos...

In view of the successful experience in the generation of pion and kaon secondary beams using a focusing crystal, it has been proposed to build at the U-70 accelerator a new-type channel of secondary particles that does not consume electric power. It has been shown experimentally that an extraction septum magnet can be protected from radiation by applying a multistrip crystal device through current septum shadowing by the crystal that involves the bulk reflection regime for the deflection of particles. The listed applications of crystals are novel in the world practice with accelerators.

With a particular focus on the experience of young people in higher education, this paper turns to the philosophical work of Cora Diamond to open up new ways of conceptualising mental health. We cl...

By introducing relative speed of two objects into Newton’s gravitational theory, Newton’s gravitational formula can be modified as: F = GMm/r2(1 + V2/C2). V is the relative speed between the two objects and C is the light speed. In order to test this formula, the paper uses it to calculate the Perihelion Precession of Mercury and light deflection near the Sun. The calculation result shows that Modified Newton’s Gravity theory and General Relative theory have same accuracy to calculate planets orbit and light deflection. It also shows that the gravitational force between two objectives with high relative speed is a bit bigger than that with low relative speed. When this speed is up to light speed, the gravitational force is two times bigger than that with zero speed.

In this study, we investigate the flame stabilization behavior in hydrogen-enriched stratified swirl flames after the flame flashes back into an annular mixing tube with an axial swirler of swirl number 0.9. Two different modes of flame stabilization, namely intermediate stabilization and flameholding, are identified. For 80% or higher hydrogen enrichment of the fuel, the flashback is found to result in flameholding. Acetone-PLIF measurements are used to assess the equivalence ratio distribution in the mixing tube. It is shown that the flow inside the mixing tube has intermittent presence of fuel-rich pockets. Furthermore, high speed laser diagnostic and simultaneous chemiluminescence imaging was carried out to understand the transition of flame propagation from the center-body boundary layer to the outer wall boundary layer. With the help of time-resolved images and simultaneous velocity fields, four different stages of flashback-to-flameholding transition were identified. It was noted that the bright flame kernels formed due to the flame's interaction with fuel-rich pockets, impose significant deflection on the approach flow in the vicinity of the outer wall boundary layer. Acute-tipped narrow flame structures were found to anchor the flame on the outer wall. These flame structures were found to accelerate upstream upon reaching the fuel-rich regions in the outer wall boundary layer.

The study of the effect of the gravitational field on the photons, based on the hypothesis of the absolute reference system, demonstrates the origin of the gravitational force. By studying the propagation of a photon in the gravitational field the change in the estimation of time is determined, resulting from the use of a clock that is affected by the gravitational field. It is proved that in all known experiments, which were carried out in order to confirm the general theory of relativity, the results based on the hypothesis of an absolute reference system agree with the corresponding results of the general theory of relativity, except for the result of the deflection of light in the gravitational field of the sun, where the experimental results confirm the hypothesis of the absolute reference system.

Physical phenomena such as arc interference, deflection in droplet transfer, and bulging in weld pool are observed in the tandem gas metal arc welding (GMAW) process. A hot-wire with opposite polarities to the leading and trailing electrodes was introduced to counter these phenomena. The effects of the hot-wire were assessed experimentally. A 3D steady-state numerical analysis model was used to calculate the temperatures and the shapes of the leading and trailing arcs, respectively, as well as the arc flows and the electromagnetic forces. The results of our experiments and our numerical analyses clarify the effects of a decrease in the electromagnetic force around tandem electrodes due to the hot-wire. This decrease mitigates arc interference and the deflection in droplet transfer. Furthermore, it plays a role in reducing the height of the bulge generated on the surface of the weld pool. These effects can prevent defects in tandem GMAW processes.

Sulfonylhydrazones are a novel hydrazone-based organic molecular photoswitch. The four derivatives with unsubstituted and o-, m- and p-nitro substituted sulfonylhydrazone (SH-1, SH-2, SH-3, and SH-4, respectively) derived from p-toluenesulfonyl hydrazide and corresponding benzaldehydes were examined with respect to their solution state photoswitching and photomechanical response in the crystalline state. All the compounds displayed UV-induced E → Z isomerization in the solution state, whereas the back conversion was slow. Single crystals of SH-3 displayed rapid and large photomechanical bending, whereas SH-1 and SH-4 crystals underwent slow bending to a comparatively lesser extent. On the contrary, SH-2 crystals did not show any photomechanical effects. The photomechanical deflection of the crystal tip of SH-1 increased linearly; for SH-3, the deflection increased in a sub-linear manner for few seconds, after which it started to revert towards the light source. For SH-4 crystals, the photo-induced tip deflection initially increased in a sub-linear fashion, after which no motion was observed even after continuous exposure to UV light irradiation. The photomechanical behavior of the crystals was also inspected with the aid of velocity-time and acceleration-time plots that unravelled the instantaneous photomechanical motion at various time intervals.

In the work on specific examples involving real copper-based alloys containing 14 weight.%Al and 3 weight.%Mn, describes the results of a study of the process of restoring the shape of a material that was defomated according to the three-point bending scheme. The studies were carried out by measuring changes in the temperature dependence of the electrical resistance and deflection of the sample, as well as by obtaining microelectronograms using an electron microscope. Since SME alloys operate under conditions of mandatory thermal cycling, the elucidation of the thermal stability of these materials is of practical interest. It is established that martensitic crystals that occur in hardened samples have a high density of packing defects and thin twins formed on the (121) γ ́ plane. One of the important features of the martensitic mechanism is the obligatory formation of martensite with defects, which is a fine structure. By comparing the curves of the electrical resistivity and the deflection, it was found that the temperature range of the increase in the deflection upon cooling coincides with the temperature range of the direct martensitic transformation. In addition to stacking faults, thin twins with a thickness of 0.01-0.04 microns are also observed in martensite crystals. It was found in the analysis that twinning in martensite occurs along the {121} γ ́ plane. It is shown that the streakiness arising during martensitic transformations is caused by stacking faults, which lie in the {121} plane at a high density of stacking faults.

The subcycle interaction of light and electrons has been one of the key frontiers in free-electron lasers, attosecond science and dynamical investigation of matter. Capturing the underlying subcycle dynamics of electrons with an optical field promises fascinating vistas with unprecedented temporal resolution. Yet the rigorous synchronization requirement has kept its realization out of reach. Here, by direct spatial observation of periodic electron bunch fringes, we demonstrate a laser streaking concept for revealing the dynamics of free electrons emitted from a plasma mirror under sub-relativistic laser intensity. Field-induced electron beam deflection demonstrates subcycle charge dynamics with a streaking speed of ~60 μrad as−1. This provides us with an attosecond-resolution metrology to obtain more direct evidence about the light-field-induced electron dynamics in the plasma mirror. Our results offer unprecedented characterization of attosecond dynamics and open the way to extensive experimental investigations of the interaction of attosecond electrons with intense lasers. By focusing a sub-relativistic infrared laser pulse onto a silica target, a periodic deflection pattern of attosecond electron pulse trains is observed. It reveals these subcycle charge dynamics with a streaking speed of ~60 μrad as−1.

This paper proposes an analytic relation for the deflection of a cantilever beam with a transverse crack subjected to dead load. The mathematical relation is deduced involving the decreased capacity of the beam to store energy, which is in direct relation with the crack position and depth. Eventually, the validity of the relation is proved by means of the finite element method.

An investigation into the effects of momentum transfer deflection methods, specifically kinetic impact and nuclear detonation, on the rotational state of a deflected object is presented. Initially,...

Transmission of 1-MeV protons through a straight polytetrafluoroethylene macrocapillary was simulated as a function of the beam diameter, ranging from 2 μ m to 0.8 mm . This study is inspired by previous work using micro beam of 1-MeV protons for which the transmission fraction was up to 90 % , whereas for usual beam it became smaller. We aim to interpret the different transmission caused by the differences in the beam diameters. Our results clearly show that the guided transmission is dependent on the beam diameter, while scattered transmission is hardly sensitive to the beam diameter. It indicates that at equilibrium the transmission fraction decreases as the beam diameter increases. The beams of different diameters formed different charge patches, and consequently produced different deflection fields, which play an important role in the decreasing guided transmission with the beam diameter. An analytic model was introduced, which reaches excellent agreement with the simulated results.

The dynamics of electrochemically produced hemispherical bubble at solid-liquid interface is investigated experimentally. Time-resolved photography is applied to measure the position of bubble wall as a function of time. By means of stroboscope schlieren photography with 1 μs exposure time it is shown that the development of instabilities of the bubble shape are general feature of the bubble dynamics in contact with the solid boundaries. The acoustic transients emitted after cavitation bubble collapse were registered with the laser beam deflection technique. Duration of the transient of 50–60 ns enables to estimate maximum pressure as 2.5 kbar, when the maximum bubble radius is 1 mm.

A new accelerator complex with new beam lines for applied research is being constructed at the Joint Institute for Nuclear Research (Dubna, Russia) as part of the Nuclotron-based Ion Collider fAcility (NICA) project. The new beam channels are the link between the NICA accelerators and the new stations for applied studies in the applied research program. The channels provide beam transport and the formation of beams with the required parameters. The floor plans, deflection dipole magnets, and beam-dynamics simulation results for the channels are discussed.

The kinetic impactor, which is a spacecraft that impacts against an Earth-threatening asteroid, is one of the potential methods for deflecting an asteroid from the Earth collision route. To improve...

Purpose Spinning slender bodies are affected by lateral Magnus forces and moments when exposed to cross-flow. The effects occurring for spinning bodies of revolution in combination with stabilising or control surfaces such as canards are not yet fully explained. Therefore the present work aims to investigate the phenomena arising from the interactions of a roll-decoupled guidance unit with a spinning rear body are investigated. Design/methodology/approach A generic tangential-ogive-cylinder projectile equipped with deflectable canards on a roll-decoupled nose is investigated by means of 3D Reynolds-averaged Navier–Stokes simulations at Mach number 2 for angles of attack up to 22 degrees. Different canard deflection angles up to 9 degrees are considered. Global aerodynamic coefficients as well as local flow fields are analysed to explain the interactions occurring between the roll-decoupled guidance unit and the spinning rear body. Findings The deflected canards lead to flow interactions resulting in lateral forces and moments even without a spinning motion of the rear part. Depending on the canard deflection angles, these forces act in or against the direction of the classical Magnus effect. For angles of attack smaller than 10 degrees it is possible for the current body geometry to directly superpose the lateral effects resulting from the fins for the non-spinning model with those occurring for the non-finned but spinning model to obtain the total forces and moments acting on a spinning model with canted canards. However, the lateral effects generated on the guidance unit itself are insignificant compared to the canard-induced effects on the rear body. Originality/value A detailed analysis of the interaction effects arising from a decoupled guidance unit containing canards with a non-spinning/spinning rear body is performed and the underlying phenomena are revealed.

The dynamics of asteroid deflection and manipulation using mass ejection are examined. First, a linearized small angular velocity and inertia tensor deviation model for close-to-principal-axis rota...

We have analyzed the effects of a simple wormhole, known as the Ellis–Bronnikov-type wormhole, on a scalar field, where, analytically, we determine solutions of bound states and show that the relativistic energy profile of this scalar field is drastically influenced by the topology of space-time characterized by the presence of a global monopole. Before this analysis, we investigated the effects of this background on the deflection of light, which is influenced by the parameters associated with the wormhole throat and the topological defect.

In 1919, the observation during a solar eclipse of the deflection of light rays from stars near the Sun decreed the validity of Einstein’s general relativity. One hundred years later, the image of the black hole M87* by the Event Horizon Telescope collaboration proved the existence of these fascinating objects on the one hand, and on the other, the validity of general relativistic magnetohydrodynamics (GRMHD) in the strong gravity regime. Numerical simulations have been used to model the accreting plasma around the black hole, whose emission is at the base of the synthetic images compared with data. Here, we briefly discuss the methods and the initialization employed for these simulations, and we briefly report the results of GRMHD axisymmetric simulations where a dynamo mechanism operates inside the disk, enhancing the magnetic field from its initial seed values up to those needed to explain the observed plasma emission.

The flow of air around a baseball and over the seam acts to slow the ball and to deflect it sideways. Turbulent flow can be visualized, and sideways deflection of the ball can be observed clearly if the ball is dropped in a glass fish tank and filmed with a high-speed camera. Results are presented for a baseball and also for a billiard ball with a metal ring attached to simulate the effect of the baseball seam.

Recent observational evidence reveals the existence of black holes in the galaxy. Using strong field lensing effect, we find out the expressions of the radius of the photon sphere, the deflection angle, the separation between the first and the other images, the ratio between the flux of the first image as well as the flux coming from all the other images for dilaton–axion black holes and compare the results with Reissner–Nordstrom black holes. We also investigate the variations of primary and secondary image positions as well as their magnifications with respect to the source position for this kind of black holes.

The pointing error (pointing deviation) of light beam is an important factor affecting the signal transmission quality of underwater optical communication system. Here we investigated the effects of weak turbulent seawater on the propagation of orbital angular momentum(OAM) modes carried by deflection Bessel Gaussian beams. The analytic expression of the received probability of the signal and crosstalk OAM mode was derived based on the theories of Rytov theory. The results show that smaller deflection has a significant effect on the improvement of signal received probability. And with the increase of the dissipation rate of the mean-squared temperature and the decrease of the rate of dissipation of kinetic energy per unit mass of fluid, the turbulence of seawater increases, and the influence of turbulence on the beam increases Our results also indicate that the received signal probability can be improved by use of deflection Bessel Gaussian beams with low OAM quantum number and long wavelength.

We investigate the effects of geometric optics as deflection of light-ray around gravitating compact object surrounded by a plasma in conformal Weyl gravity. We have obtained that the expression for the deflection angle of the light in a vacuum is modified due to the effect of [Formula: see text] responsible for the Weyl correction to the gravity. The effect of the plasma surrounding the black hole in Weyl gravity to the deflection angle has been also studied. We have also provided the analysis of the magnification of image source due to gravitational lensing around black hole in Weyl gravity in the presence of plasma environment. Finally, we have analyzed the shadow of the black hole in Weyl gravity in the presence of plasma.

Acoustic metasurfaces are artificial structures, one of whose functions is to achieve plane wave focusing due to the phase gradient transformation of specific structural units. However, previous periodic acoustic metasurfaces for plane wave focusing have drawbacks such as discrete operating frequency, large focus aberration, obvious sidelobes, etc. Here, we propose periodic folded, periodic curved, aperiodic folded, and aperiodic curved acoustic metasurfaces with filling medium, which use continuous-phase-transformation to realize the control of acoustic waves. The results show that, all four acoustic metasurfaces can achieve sub-wavelength focusing, with small focus aberrations and almost no sidelobes. Furthermore, the periodic and aperiodic curved metasurfaces use continuous deflection angles to achieve more efficient focusing than that of the periodic and aperiodic folded metasurfaces; aperiodic folded and curved metasurfaces can focus for the continuous operating frequency which is different from the discrete operating frequency in the previous periodic metasurfaces. The continuous-phase-transformation acoustic metasurface (CPTAM) proposed in this paper will have a wide range of applications in non-destructive testing, medical imaging, engineering technology, etc.