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Micromagnetic simulations are used to investigate the effect of an external magnetic field on the interaction between domain walls and linearly polarized propagating spin waves in synthetic antiferromagnets. Two regimes with a sharp transition between them are found. At large fields, spin waves are strongly reflected by the domain wall and, consequently, the latter is propelled forward. At low fields, however, there is no reflection and yet the domain wall undergoes a small forward displacement, which is attributed to the change in linear momentum of the magnons as they pass through the domain wall and to the imbalance in the population of the two oscillation modes present in the linearly polarized excitation. The transition between the two regimes occurs at the field value for which the excitation frequency falls below the threshold of the high-frequency mode. [ABSTRACT FROM AUTHOR]

The impacting phenomenon of nanodroplets has received much attention due to their importance in various industrial applications. The oblique impingement of single droplets is well understood; however, the effect of oblique angle on impacting the dynamics of multiple droplets at the nanoscale is very limited. To address this gap, we perform molecular dynamics (MD) simulations to study the impacting dynamics of binary nanodroplets with various oblique angles (αob) and Weber numbers (We). Using MD simulations, we directly capture the detailed morphological evolution of the impacting binary droplets with various given conditions. Compared to the oblique impingement of a single droplet, the evolution of impacting binary droplets involves two novel dynamic characteristics: the asymmetric dynamics with droplet preferential spreading in the y direction and the rotating of the coalescing droplet. The mechanisms underlying are well studied. The asymmetric dynamics is a result of the velocity gradient of the outer edge of the spreading droplet, and the rotating effect is due to the change in angular momentum induced by surface force. The analysis and study of these phenomena have never been mentioned in previous studies of single droplet. Finally, we investigate the effect of αob and We on normalized moving distance (L/Dsin) and contact time (tc). This work paves the way for offering a comprehensive understanding of the oblique impingement of binary nanodroplets. [ABSTRACT FROM AUTHOR]

Despite the tremendous advances in aircraft design that led to successful powered flights of aircraft as heavy as the Antonov An-225 Mriya, which weighs 640 tons, or as fast as the NASA-X-43A, which reached a record of Mach 9.6, many characteristics of bird flight have yet to be utilized in aircraft designs. These characteristics enable various species of birds to fly efficiently in gusty environments and rapidly change their momentum in flight without having modern thrust vector control (TVC) systems. Vultures and seagulls, as examples of expert gliding birds, can fly for hours, covering more than 100 miles, without a single flap of their wings. Inspired by the Great Black-Backed Gull (GBBG), this paper presents "CGull", a non-flapping unmanned aerial vehicle (UAV) with wing and tail morphing capabilities. A coupled two degree-of-freedom (DOF) morphing mechanism is used in CGull's wings to sweep the middle wing forward and the outer feathered wing backward, replicating the GBBG's wing deformation. A modular two DOF mechanism enables CGull to pitch and tilt its tail. A computational model was first developed in MachUpX to study the effects of wing and tail morphing on the generated forces and moments. Following the biological construction of birds' feathers and bones, CGull's structure is mainly constructed from carbon-fiber composite shells. The successful flight test of the proof-of-concept physical model proved the effectiveness of the proposed morphing mechanisms in controlling the UAV's path. [ABSTRACT FROM AUTHOR]

In this article, we investigated the heat and mass transfer of immiscible fluid flow in symmetric two‐vertical regions with a porous matrix in region‐II. The properties of heat generation and absorption are discussed. The channel, consisting of two vertical regions, is filled with a porous matrix with viscous fluids. In both cases, we considered the fluids that undergo Newtonian heat generation and absorption. It was assumed that the porous matrix's channel wall was thermally stable and electrically non‐conducting. The analytical method is used to solve governing equations. Variations in Brinkman Number (Br), Biot Number (Bi), Grashof (Gr) number, viscosity ratio (m), heat generation, and thermal conductivity are illustrated graphically. And we examined the increase in Grashof number, which has effects on fluid flows in both regions. Similarly, the change of heat and momentum transmission in porous media is greatly affected by the viscosity, channel width, source, and sink. Also, when the Grashof number increases, buoyancy increases, leading to an increase in the fluid flow for heat generation and absorption. [ABSTRACT FROM AUTHOR]

Background: Spot‐scanning Proton Arc (SPArc) has been of significant interest in recent years because of its superior plan quality. Currently, the primary focus of research and development is on deliverability and treatment efficiency. Purpose: To address the challenges in generating a deliverable and efficient SPArc plan for a proton therapy system with a massive gantry, we developed a novel SPArc optimization algorithm (SPArcDMPO) by directly incorporating the machine‐specific parameters such as gantry mechanical constraints and proton delivery sequence. Methods: SPArc delivery sequence model (DSMarc) was built based on the machine‐specific parameters of the prototype arc delivery system, IBA ProteusONE®, including mechanical constraint (maximum gantry speed, acceleration, and deceleration) and proton delivery sequence (energy and spot delivery sequence, and irradiation time). SPArcDMPO resamples and adjusts each control point's delivery speed based on the DSMarc calculation through the iterative approach. In SPArcDMPO, users could set a reasonable arc delivery time during the plan optimization, which aims to minimize the gantry momentum changes and improve the delivery efficiency. Ten cases were selected to test SPArcDMPO. Two kinds of SPArc plans were generated using the same planning objective functions: (1) original SPArc plan (SPArcoriginal); (2) SPArcDMPO plan with a user‐pre‐defined delivery time. Additionally, arc delivery sequence was simulated based on the DSMarc and was compared. Treatment delivery time was compared between SPArcoriginal and SPArcDMPO. Dynamic arc delivery time, the static irradiation time, and its corresponding time differential (time differential = dynamic arc delivery time—static irradiation time) were analyzed, respectively. The total gantry velocity change was accumulated throughout the treatment delivery. Results: With a similar plan quality, objective value, number of energy layers, and spots, both SPArcoriginal and SPArcDMPO plans could be delivered continuously within the ± 1 degree tolerance window. However, compared to the SPArcoriginal, the strategy of SPArcDMPO is able to reduce the time differential from 30.55 ± 11.42%(90 ± 32 s) to 14.67 ± 6.97%(42 ± 20 s), p < 0.01. Furthermore, the corresponding total variations of gantry velocity during dynamic arc delivery are mitigated (SPArcoriginal vs. SPArcDMPO) from 14.73 ± 9.14 degree/s to 4.28 ± 2.42 degree/s, p < 0.01. Consequently, the SPArcDMPO plans could minimize the gantry momentum change based on the clinical user's input compared to the SPArcoriginal plans, which could help relieve the mechanical challenge of accelerating or decelerating the massive proton gantry. Conclusions: For the first time, clinical users not only could generate a SPArc plan meeting the mechanical constraint of their proton system but also directly control the arc treatment speed and momentum changes of the gantry during the plan optimization process. This work paved the way for the routine clinical implementation of proton arc therapy in the treatment planning system. [ABSTRACT FROM AUTHOR]

This paper provides a detailed historical review of the cavity flow phenomena in fluid mechanics, from recorded studies in the late 19th century to more recent work. Research has been reviewed, independently and in culmination with other studies, to summarise the major and minor governing parameters of the flow. Outlined are influences of technology, regarding numerical models, experimental methods, analysis, and control techniques. All Mach regimes are assessed; low incompressible, sub-, trans-, super- and hypersonic where substantial research was available. A large variety of cavity geometry was presented, mostly rectangular, with more complex features akin to industry application, and where available, assessment of the boundary layer structure is also included. Conclusions on present understanding, and requirements for future work are given, with an aligned set of available data. Cavity flow-field initialisation and development is dependent on; upstream (U/S) flow conditions of; airspeed M ∞ , boundary layer (BL) disturbance (δ), displacement (δ ∗) and momentum (θ) thickness, either laminar or turbulent, and cavity geometry; length (L), depth (D) and width (W), with ratios L / D , L / W , δ / D and L / θ defining cavity response. I.e., a narrow cavity with a thin BL U/S tends toward a periodic 3D flow-field, with 3D effects and periodicity decreasing as W and δ increase. Control is achievable through SL stabilisation via spanwise disturbance from the leading edge (LE), or thickening the BL, thus shear layer (SL). Experiments are preferred over numerical models, due to the inefficiency and high cost of required models (Colonius, 2001; Rowley and Williams, 2006; Lawson and Barakos, 2011). We understand effects of L , D , L / D , and M ∞ , thus future work should focus on W , BL and how they impact mode switching and stream/spanwise flow propagation. Also introducing more complex geometry, realistic to application, to observe additional 3D effects and U/S momentum change, in contribution to a scaling parameter and determination of criteria for activation of material displacement. [ABSTRACT FROM AUTHOR]

In March 1969, the Sino-Soviet military clash on Zhenbao Island marked a critical juncture in the development of the US-China rapprochement. Despite Mao's solid grip on power and the opportune momentum for policy change after the Soviet invasion of Czechoslovakia, a formidable anti-US sentiment had taken shape since the founding of the People's Republic of China, especially during the Cultural Revolution, which provided insufficient opportunities to change the diplomatic course. Eventually, Mao directly ordered an ambush on Zhenbao to persuade the public by heightening tensions with Moscow. When the Soviet threat had surpassed that of the United States and the justification for a conciliatory approach toward Washington was prepared, Mao resumed a restrained strategic move toward Sino-American rapprochement. The Zhenbao incident was Mao's version of "manufacturing consent", as he laid the foundation for the trilateral relationship's transformation. [ABSTRACT FROM AUTHOR]

Understanding photoinjection in semiconductors—a fundamental physical process—represents the first step toward devising new opto-electronic devices, capable of operating on unprecedented time scales. Fostered by the development of few-femtosecond, intense infrared pulses, and attosecond spectroscopy techniques, ultrafast charge injection in solids has been the subject of intense theoretical and experimental investigation. Recent results have shown that while under certain conditions photoinjection can be ascribed to a single, well-defined phenomenon, in a realistic multi-band semiconductor like Ge, several competing mechanisms determine the sub-cycle interaction of an intense light field with the atomic and electronic structure of matter. In this latter case, it is yet unclear how the complex balance between the different physical mechanisms is altered by the chosen interaction geometry, dictated by the relative orientation between the crystal lattice and the laser electric field direction. In this work, we investigate ultrafast photoinjection in a Ge monocrystalline sample with attosecond temporal resolution under two distinct orientations. Our combined theoretical and experimental effort suggests that the physical mechanisms determining carrier excitation in Ge are largely robust against crystal rotation. Nevertheless, the different alignment between the laser field and the crystal unit cell causes non-negligible changes in the momentum distribution of the excited carriers and their injection yield. Further experiments are needed to clarify whether the crystal orientation can be used to tune the photoinjection of carriers in a semiconductor at these extreme time scales. [ABSTRACT FROM AUTHOR]

This paper is mainly concerned with the existence of mild solutions and approximate controllability for a class of fractional semilinear systems with instantaneous and non-instantaneous impulses. By applying the Kuratowski measure of noncompactness and ρ -set contractive fixed-point theorem, the results for the considered system were obtained. In the end, an example was studied to support the main results. [ABSTRACT FROM AUTHOR]

The study object of this paper is the aerodynamic processes during the movement of an unmanned aerial vehicle flying low over the underlying surface. The ground effect is known to enhance the aerodynamic performance of low-flying aircraft, particularly larger ones. However, this effect is most noticeable for large objects. Unmanned vehicles are typically characterized by their relatively compact geometry. This study explores the aerodynamic processes involved in the flight of a small-sized vehicle using the principle of dynamic support over a surface. The particular prototype of the unmanned aerial vehicle suggested by the authors has been examined herein. The aim of the study is to evaluate the aerodynamic forces affecting a small-sized unmanned high-speed vehicle that employs the dynamic principle of support over the surface (WIG craft) by using CFD modeling. In contrast to most available studies on the ground effect, a 3D problem statement was used in this work. Computational experiments have visualized the physical fields surrounding an aircraft in flight over the ground. This study determines how the distance from the surface affects the aerodynamic properties of a small-sized aircraft, as well as the height of the effective zone where ground effect influences the small-sized WIG craft within 0.3 ≤ ... ≤ 0.7. It has been shown that approaching the surface leads to a shift in the center of pressure of the vehicle, which leads to a change in aerodynamic momentum. This phenomenon must be taken into account when designing a control system to provide a stable flight. The study’s findings are directly relevant for the development of a type of unmanned vehicles that use the dynamic principle of support over the surface. [ABSTRACT FROM AUTHOR]

This study proposes a hybrid pitching motion for oscillating flat plates aimed at augmenting the energy extraction efficiency of an energy harvester. The proposed hybrid pitching motion, within the first half cycle, integrates a non-sinusoidal movement starting at t/T = 0 and progressing to t/T = 0.25, with a sinusoidal movement initiating after t/T > 0.25 and continuing to t/T = 0.5. The second half of the cycle is symmetric to the first half but in the opposite direction. The calculated results show that the proposed hybrid pitching motion outperforms both the sinusoidal and the non-sinusoidal motions. The hybrid pitching motion merges the merits of both the sinusoidal and non-sinusoidal motions to optimize pitch angle variation. This integration is pivotal for enhancing the overall power output performance of an oscillating energy harvester characterized by momentum change that enhances the orientation of the heaving movement, smoother motion transitions, and consistent energy harvesting. The power generation is obtained at wing pitch angles of 55°, 65°, 70°, 75°, and 80° during a hybrid pitching motion. The proposed hybrid pitching motion, set at a pitch angle of 70°, achieves a maximum power output that exceeds the oscillating flat plate using a sinusoidal pitching motion by 16.0% at the same angle. [ABSTRACT FROM AUTHOR]

Electric propulsion, which is an advanced form of thrust production, is widely used in small satellites. Measuring the thrust of electric propulsion in an orbit is difficult because it is very small (μN∼mN). However, the thrust of electric propulsion can be determined by evaluating the change in the speed of a momentum wheel. The contributions of this paper mainly include two aspects: 1) a robust PID controller and 2) a thrust inversion method. The torque of the electric propulsion is regarded as the disturbance torque in this paper. To achieve finite-time attitude stabilization of a satellite during electric propulsion, a robust PID controller is designed. Furthermore, the thrust of the electric propulsion can be determined in the stable attitude of the satellite by only measuring the speed derivative of the momentum wheel. Compared with the traditional thrust inversion method, the designed thrust inversion method is simple and effective and does not use a filtering algorithm. In the HIL experiment, the error rate between the inverted thrust (31.287 μN) and the designed thrust (30 μN) is 4.29%. Most importantly, the thrust inversion method is verified in orbit based on the small satellite APSCO SSS-1, which is consistent with the HIL experimental results and ground test results. • The torque of electric propulsion is regarded as the disturbance torque. • The controller can fulfill finite-time attitude stabilization of the satellite. • Thrust can be calculated by evaluating the speed change of the momentum wheel. • Thrust inversion method is verified in orbit based on the small satellite SSS-1. [ABSTRACT FROM AUTHOR]

We have translated the results of N -body simulations of one barred model into the language of action variables and frequencies. Using this language, we analysed the behaviour of all orbits in the model on a large time-scale at the stage of a mature bar. We show that the orbits join the bar while preserving their adiabatic invariant, which takes into account the three-dimensional structure of the orbits. This allows us to apply the concept of the Lynden-Bell derivative for each of these orbits and trace how the sign of the derivative changes; i.e. how asynchronous changes in angular momentum Lz and orbital precession rate Ωpr (normal orbital mode) change to synchronous (abnormal mode). The transition to the abnormal mode occurs when Ωpr reaches the angular velocity of the pattern Ωp, after which the orbit becomes stuck in the bar trap. All this happens against the background of secular changes in actions (Lz decreases, J R and Jz increase). At the same time, corotating particles near two stable Lagrange points are also subject to secular changes in their actions. They increase Lz and drift to the periphery, shifting corotation outwards. We also show that a change in the orbital mode from normal to abnormal and the trapping of orbits in a bar are possible only when the bar speed decreases with time, regardless of what is causing the bar to slow down. Our findings clarify and expand the picture of bar formation and evolution in numerical models. [ABSTRACT FROM AUTHOR]

Western democracies are experiencing a widespread shift towards greater recognition of transgender rights in public policy, yet the timing of change differs across states. To explain this variation, I present a novel theoretical framework called "policy momentum." Unlike existing work on policy diffusion, which typically emphasizes domestic or international processes, I theorize how the combined pressure from each level creates the conditions for policy change to occur. Empirically, I contrast the creation of national human rights policies to protect transgender individuals in Canada (2017) and Australia (2013). Using process‐tracing and within‐case analyses, and drawing on elite interviews, primary documents, and Hansard records, I demonstrate the decisive interaction of subnational legislative changes with an emerging global norm to produce transgender policy change. This paper thus contributes to our understanding of LGBTQ+ public policy while also providing a framework for explaining the conditions for cross‐national policy change more broadly. [ABSTRACT FROM AUTHOR]

The self-force expansion allows the study of deviations from geodesic motion due to the emission of radiation and its consequent back-reaction. We investigate this scheme within the on-shell framework of semiclassical scattering amplitudes for particles emitting photons or gravitons on a static, spherically symmetric background. We first present the exact scalar two-point amplitudes for Coulomb and Schwarzschild, from which one can extract classical observables such as the change in momentum due to geodesic motion. We then present, for the first time, the three-point semiclassical amplitudes for a scalar emitting a photon in Coulomb and a graviton on linearised Schwarzschild, outlining how the latter calculation can be generalized to the fully non-linear Schwarzschild metric. Our results are proper resummations of perturbative amplitudes in vacuum but, notably, are expressed in terms of Hamilton's principal function for the backgrounds, rather than the radial action. [ABSTRACT FROM AUTHOR]

The pursuit of value and equity have been put on a legal footing in the NHS with the arrival of the legal duty for all in the NHS to improve health and well-being of the population served, to provide fair access to high quality healthcare, and to use resources sustainably and efficiently. Recognising this we used analysis of variation to help us understand the degree to which we were fulfilling our new duty for people with back pain in Mid-Nottinghamshire and where there might be opportunities for value improvement. MSK Together is a group of clinical and managerial representatives from providers, purchasers, local government, and patients who work collectively to optimise the use of resources for people with MSK conditions in Mid-Nottinghamshire. Back pain is the third largest burden of disease in the locality, and the largest cause of disability, so it is of strategic importance to MSK Together—we wanted to know about, and act on, opportunities for value improvement across the population of people with back pain. In 2019/20, after adjusting for age and sex, we found a greater than three-fold variation among general practices in age-sex standardised rates of all hospital service usage for back pain conditions. When looking at a four-year period (2016/17–2019/20), the observed variation increased to eight-fold for (with narrow 95% confidence intervals). When looking at procedures (e.g., surgery or injections), the standardised variation among general practices was six-fold in 2019/20. The deprivation score of the general practice (a heterogenous measure given the mixed neighbourhoods many general practices serve) showed little correlation to the rates observed and did not appear to justify the variation. When we looked at the deprivation of the neighbourhood from which the individuals receiving back pain procedures came, there appeared to be a weak correlation in terms of lower rates of intervention in the least-deprived compared with the most-deprived communities. This correlation was not tested statistically. People receiving hospital services for back pain appeared to receive the first episode of care most often in their 40s (working age), compared with people from the least-deprived areas who received care most commonly in their 60s (approaching retirement). When we looked at the interventions provided in Mid-Nottinghamshire for back pain, 29 interventions were provided to 17,225 people. Using a recent NICE evaluation of cost-effectiveness of back pain interventions, we established that, of these 29 interventions, 16 have evidence of improving the quality of life, for nine there was no evidence of benefit or harm, for three there was evidence that they do not provide an improvement in quality of life, and for one there was possible evidence of harm. The total cost of interventions was estimated at £4.5 million and, using the evidence from the NICE review, the total quality adjusted life year (QALY) gain to the treated population of people with back pain was calculated to be 4,571 QALYs. After discussions among the MSK Together group, it was agreed that some interventions could be stopped or scaled down, and new interventions introduced (in particular, in more-deprived neighbourhoods). Within the same estimated cost envelope of £4.5 million, the QALY gain was predicted to increase to 7702 QALYs and, by targeting QALY-related interventions to people from deprived neighbourhoods, reduce inequity (and therefore health inequalities). Using variation helped us identify areas for improvement and generated a momentum for change among the MSK Together group. By examining what we were doing, the associated costs, and the likely QALY benefits (from research evidence), we identified lower value interventions to stop or reduce and new interventions to introduce, achieving greater health gain for people with back pain with no additional resource requirements. [ABSTRACT FROM AUTHOR]

Successful nonstate climate actions can scale up their efforts and/or have their approaches replicated by others. To strengthen these "catalytic impacts" and their contribution to global mitigation and adaptation efforts, multiple international awarding mechanisms have been established, including Momentum for Change, launched by the United Nations Framework Convention on Climate Change (UNFCCC). To assess the actual value of awarding mechanisms for fostering catalytic impacts among nonstate climate actions, this article identifies drivers and barriers for catalytic impacts and the extent to which Momentum for Change addresses them, using the concept of enabling power. Research results indicate that only a selective range of drivers and barriers for catalytic impact is actually addressed through Momentum for Change, which mainly strengthens reputation as a driver. Overall, the study demonstrates that the enabling power of Momentum for Change relies on the legitimacy of the UNFCCC in climate governance. However, the extent to which awarding mechanisms help foster catalytic impact is also dependent on an initiative's individual context, which may affect its ability to capitalize on reputational benefits. [ABSTRACT FROM AUTHOR]

The micro- and nanoelectromechanical system (MEMS and NEMS) devices based on two-dimensional (2D) materials reveal novel functionalities and higher sensitivity compared to their silicon-base counterparts. Unique properties of 2D materials boost the demand for 2D material-based nanoelectromechanical devices and sensing. During the last decades, using suspended 2D membranes integrated with MEMS and NEMS emerged high-performance sensitivities in mass and gas sensors, accelerometers, pressure sensors, and microphones. Actively sensing minute changes in the surrounding environment is provided by means of MEMS/NEMS sensors, such as sensing in passive modes of small changes in momentum, temperature, and strain. In this review, we discuss the materials preparation methods, electronic, optical, and mechanical properties of 2D materials used in NEMS and MEMS devices, fabrication routes besides device operation principles. [ABSTRACT FROM AUTHOR]

Recently, Ahn et al. created dumbbell-shaped silica nanoparticles, then optically levitated in vacuum, capable of spinning at 300 billion revolutions per minute, driven only by the force and torque of laser. This is by far the fastest spinning object in the world. We show that in this system, there is an additional change in momentum (or extra force) that is proportional to the change in the angular momentum of the particle (or torque). We suggest that this effect also applies to microscopic particles. In the experiment of Ahn et al., although the angular momentum of the particle itself L is large, the rate of change of the angular momentum L ̇ may not be large. Therefore, experimentally, the physical effects associated with changes in angular momentum can be verified either by applying very strong force and torque to the particle, or by allowing the axis of rotation of the particle to find a way to change very quickly. [ABSTRACT FROM AUTHOR]

This work studies the tunability of absorbed energy rate ( Q tot ) from a double quantum dot (DQD)-metal nanoparticle (MNP) system under changing the transition momenta of the quantum dot (QD)-QD and wetting layer (WL)-QD. The modeling considers the WL and the orthogonalized plane wave (OPW) for WL-QD transitions, and the study is taken when the plasmonic electromagnetically induced transparency (PEIT) is attained. PEIT was not studied earlier under OPW consideration, which is essential for considering the formulation of the WL-QD system. Also, our modeling is a material property that does not take an averaging of energies and momenta as in the literature. It calculates the QD energy states, QD-QD, and WL-QD transition momenta. It is shown that a slight variation in the QD-QD momentum gives efficient changes in the Q tot . Reducing the WL-QD valence band momenta is more efficient in Q tot reduction while the spectrum exhibits four PEIT windows. Also, controlling the WL-QD conduction band transition gives six PEIT windows. These results are essential in biomedical and quantum computer applications. It is significant and is not obtained with other QD-MNP systems. It results from the flexibility of the DQD-MNP system used here, not found in other systems. One of the WL-QD momenta has an inverted effect on Q tot . The results in this work show that the transition momenta can tune PEIT, which refers to a high possibility of designing the structure according to the application required. [ABSTRACT FROM AUTHOR]

Rammohun Roy, the liberal reformer of the early nineteenth century, and perhaps the first Indian to comprehensively embrace the ideal of modernity, encountered a volley of criticisms during his lifetime and beyond. Of all this, the twin charges, that is, his reformist project denigrated India's ancient sociocultural heritage and he acted as an unconscious tool of the British Empire in India, have recently gathered a new momentum in the context of the changing dynamics of Indian politics. This article seeks to engage with this line of argument by examining the political, social and religious dimensions of Roy's thought and action. It is accepted that he was inspired by the ideals of Western modernity, which, he believed, held the key to the long-term intellectual, sociocultural, political and economic development of the Indians. He also supported the continuation of British rule at least for a period of time to allow wider dissemination of these progressive values in India and to pave the way for its all-round advance. It is contended, however, that neither did he intend to undermine India's classical heritage, nor did he favour mindless aping of the West. On the contrary, he took ample care to integrate indigenous sociocultural components into his proposed roadmap for the future. Thus, his liberal agenda had evident 'conservative' underpinnings that arguably put a new spin on the idea of modernity. [ABSTRACT FROM AUTHOR]

Based on a collaborative auto-ethnographic approach, this paper examines how external stakeholders can influence organizational change processes and outcomes in a public sector context. Existing change literature suggests that stakeholder management and collaboration are critical for achieving change results. Although the role of internal stakeholders has been documented, we know less about how external stakeholders can influence planned change. To explore this, we adopted a variant of collaborative auto-ethnography in which the first-hand experiences of a top manager combined with extensive media coverage were retrospectively made sense of through joint reflection and theorizing with an outside academic. Drawing on stakeholder theory and the concept of momentum for change, we show how external stakeholders can either amplify or suppress the momentum for change, thereby ultimately affecting goal attainment. The slightly adjusted CAE methodology offers new opportunities for academic/practitioner collaborations to advance change practice and theory. [ABSTRACT FROM AUTHOR]

The world faces multiple intersecting crises, several of which are existential. The current dominant economic design is at their root cause, leading to increased advocacy for alternative economic approaches, including Wellbeing Economy. However, the role of culture, both as an objective and as a means of achieving a Wellbeing Economy, is largely absent. In this article, we review how culture has been misunderstood as being dependent on the attainment of basic needs rather than an ever-present, vital, but undervalued attribute of all societies. We discuss how neoliberal economics has individualised and commodified culture, valuing it only as an engine of economic growth and tradeable capital, all of which has led to a substantial diminution and fraying of the social fabric which any positive social transformation will rely upon. Finally, we demonstrate why culture is an essential precondition for the creation of momentum for change through the conversations, shared understandings, new narratives, and communal spaces of all forms which cultural flourishing creates. We conclude by arguing that advocates for a Wellbeing Economy, and similar economic models, such as Doughnut Economics and Foundational Economies, should prioritise and embed support for cultural development as a non-commodified social asset if we are to adequately respond to current crises and navigate to a flourishing and habitable future for ourselves and our descendants. [ABSTRACT FROM AUTHOR]

We investigate the path integral representation of the scalar propagator in a background gluon field, extending beyond the eikonal approximation by considering all gauge field components and incorporating its x− dependence. Utilizing the worldline formalism, we integrate the Schwinger proper time to express the scalar propagator in light-cone coordinates, facilitating a direct comparison with known results in the literature. The derived propagator captures the change of longitudinal momentum of the projectile within the medium. In the high-energy limit, our result simplifies to the effective gluon propagator employed in the BDMPS-Z formalism. Hence, we propose that our outcome serves as a foundational point for investigating corrections to the BDMPS-Z spectrum arising from the longitudinal momentum transfer of the radiated gluon with the medium, as well as for studying collisional energy loss phenomena. Lastly, by employing an expansion around the classical saddle point solution, we systematically derive an eikonal expansion in inverse powers of the boost parameter, encompassing corrections related to longitudinal momentum transfer and interactions of the projectile with the transverse component of the field. [ABSTRACT FROM AUTHOR]

Drops falling on substrates with varying wettability exhibit distinct morphologies. However, the relation between the impact force exerted by a water drop and the substrate wettability has not been thoroughly explored. In this paper, we investigate the effect of contact angle (ranging from 40° to 180°) on the impact force of water drops, along with the spreading diameter, rim height, and retracting velocity. Our attention is focused to the inertial regime with the Weber number ranging from 30 to 100, which enables us to rationalize the dynamic relations and to correlate the kinematics of the drop with the impact force through scaling analysis. We find that substrate wettability has insignificant effect on the first force peak, which arises mainly from the momentum change during the initial impact. However, it does influence the second force peak, which originates from the momentum change in the flow redirecting from the radial inward direction to the vertical direction, accompanied by a column-shape Worthington jet. The second peak force gradually diminishes as the contact angle decreases, until it becomes indistinguishable below 40°, while the time at which the second peak force emerges is delayed. [ABSTRACT FROM AUTHOR]

Ice hockey has long been defined by a level of violence not seen in other sports. The rough-and-tough vigilante nature of the game was often employed as a method of enticing fans. Play in the National Hockey League (NHL) evolved throughout the 20th century as the rules governing it did. The nuances of what was allowed on the ice was slowly defined, but the league always fell short of an outright ban on fighting. Notably, the NHL allows fighting while international and Olympic leagues do not. Proponents of fighting's continued presence in the NHL argue that it can attract fans, facilitate momentum changes, help win games, and allows for social regulation on the ice. However, analyses of these theories have found little definitive evidence, calling the utility of fighting into question. The economics of fighting in hockey reveal high salary payouts, increased cost of injury, and a lack of correlation with ticket sales. Additionally, there is a concern for concussions sustained during fighting which has the potential for long term, detrimental mental health effects for athletes. In this analysis, we explore the history and evolution of fighting in the NHL, as well as the reasons behind its continued presence in the game, the risks associated with fighting, and the economics behind it all. Based upon these bodies of evidence, we make a proposal regarding the future of fighting in the NHL. [ABSTRACT FROM AUTHOR]

Prior research has produced insight into the formation and collaborative dynamics of event leveraging-related partnerships in the pre- and during- Games stages. However, less is known about the evolution of these partnerships in the post-event era. This study aims to examine a post-games iteration of a cross-sector leveraging partnership group: the Provincial Parasport Collective (PPC). Specifically, this study focuses on investigating (1) factors contributing to post-event collaboration; (2) strategies, structures, and leadership mechanisms for the collaboration process; (3) and challenges PPC partners encountered in the post-event era. Core data include (1) organizational archival documents related to PPC's practices, strategies, and structures from 2016 to 2020, and (2) eight first-hand interviews with key representatives of the PPC. Results show that the PPC's ongoing collaboration was shaped by a combination of institutional field, local community, and organizational levels of conditions. In the collaboration process, the Collective first focused on enhancing mutual understanding among partners, building a collective vision and principles for working together, and engaging in formal planning. In the years following, the Collective devoted effort to formalizing collaborative structures and leadership mechanisms, adding leadership and managerial support, and optimizing communication mechanisms. Despite its progress, the PPC also encountered challenges during the collaboration process, including group size, lack of cross-pillar communication, and changing momentum over time. We expect that the findings of this study will shed light on cross-sector partnership sustainability and provide practical suggestions about the tactics for supporting ongoing strategic alliances. [ABSTRACT FROM AUTHOR]

Stars in the Galactic disc, including the Solar system, have deviated from their birth orbits and have experienced radial mixing and vertical heating. By performing hydrodynamical simulations of a galactic disc, we investigate how much tracer particles, which are initially located in the disc to mimic newborn stars and the thin and thick disc stars, are displaced from initial near-circular orbits by gravitational interactions with giant molecular clouds (GMCs). To exclude the influence of other perturbers that can change the stellar orbits, such as spiral arms and the bar, we use an axisymmetric form for the entire galactic potential. First, we investigate the time evolution of the radial and vertical velocity dispersion σR and σz by comparing them with a power-law relation of σ  ∝  t β. Although the exponents β decrease with time, they keep large values of 0.3 ∼ 0.6 for 1 Gyr, indicating fast and efficient disc heating. Next, we find that the efficient stellar scattering by GMCs also causes a change in angular momentum for each star and, therefore, radial migration. This effect is more pronounced in newborn stars than old disc stars; nearly 30 per cent of stars initially located on the galactic mid-plane move more than 1 kpc in the radial direction for 1 Gyr. The dynamical heating and radial migration drastically occur in the first several hundred Myr. As the amplitude of the vertical oscillation increases, the time spent in the galactic plane, where most GMCs are distributed, decreases, and the rate of an increase in the heating and migration slows down. [ABSTRACT FROM AUTHOR]

More than half the world's coastlines are rocky, but rip‐current dynamics on these topographically complex shores have not been studied. Field experiments on a typical rocky shore using video, drifters, and in‐situ current meters and pressure sensors reveal that incoming narrow‐banded swells result in incident wave groups that force breakpoint low‐frequency (LF) waves, which act in phase inside the surf zone to generate set‐up, run‐up, overtopping, and mass flux, pooling water atop the shore. Set‐up is enhanced by the change in momentum of the LF waves owing to dissipation by bottom friction over the rough seafloor, and by depth‐limited breaking, evidenced by low reflection. A 1D momentum balance results in a mean bottom‐drag coefficient of 1 owing to the rough bottom and vegetation. During wave‐group minima, the hydraulic head of the pooled water forces a return flow through a network of incised feeder channels that converge to a primary surge channel, directing flow offshore. The rip current extends three surf‐zone widths offshore with a maximum velocity of 1 m/s, and (in contrast to sandy shores) flow exits the surf zone, augmenting cross‐shore transport. Rip current strength is a function of channel hypsometry, overtopping, and exit constriction, factors that vary with the tide. As the tide rises, the mean flow decreases as the hydraulic head decreases and the constriction diminishes. Similar to rip currents on sandy beaches, rip currents on rocky shores are modulated by tides and sea‐swell, but they differ in geometric scale and forcing mechanism. Plain Language Summary: A series of field experiments are performed to understand rip currents associated with surge channels, a characteristic of rocky shores. Information from video observations, Global Positioning System‐equipped drifters, and bottom‐mounted current and pressure sensors was obtained for a low‐lying channel (called a surge channel) at the Hopkins Marine Station, Pacific Grove, CA, which defines the rocky shore rip current. The surge channel is a feeder‐channel network that converges into a primary channel, acting like a nozzle. The strength of the rocky shore rip current and its pulsations are governed by the sea swell waves, the modulated wave group, the tidal elevation, and surge channel geometry. Rocky‐shore surge‐channel rip currents differ from the common rip currents on sandy shores. The differences are related to the steep bottom morphology of rocky shores, which does not adjust over time to incoming sea‐swell waves and has a much smaller geometric scale than rip current morphology for sandy shores; the different morphology results in different forcing mechanisms. In addition, the significantly greater bottom roughness of rocky shores enhances the forcing mechanism. These differences modify the wave transformation, bottom friction, and rip‐current response. Our field experiments describe the kinematics and dynamics of a rocky shore rip current. Key Points: Rocky‐shore rip‐current strength varies with sea swell and low‐frequency (LF) wave forcing, channel geometry and hypsometry, and tide elevationLF pulsations are a significant contribution to the rip currents and change from a reflective to dissipative process with tideIn contrast to rip currents on sandy beaches, retention on this rocky shore is low, augmenting cross‐shore transport [ABSTRACT FROM AUTHOR]

We study the four-dimensional relationships between magnetic activity, rotation, mass, and age for solar-type stars in the age range 5–25 Myr. This is the late-pre-main-sequence (l-PMS) evolutionary phase when rapid changes in a star's interior may lead to changes in the magnetic dynamo mechanisms. We carefully derive rotational periods and spot sizes for 471 members of several l-PMS open clusters using photometric light curves from the Zwicky Transient Facility. Magnetic activity was measured in our previous Chandra-based study, and additional rotational data were obtained from other work. Several results emerge. Mass-dependent evolution of rotation through the l-PMS phase agrees with astrophysical models of stellar angular momentum changes, although the data suggest a subpopulation of stars with slower initial rotations than commonly assumed. There is a hint of the onset of unsaturated tachoclinal dependency of X-ray activity on rotation, as reported by Argiroffi et al., but this result is not confidently confirmed. Both X-ray luminosity and starspot area decrease approximately as t −1 for solar-mass stars, suggesting that spot magnetic fields are roughly constant and l-PMS stars follow the universal solar-scaling law between the X-ray luminosity and surface magnetic flux. Assuming convective dynamos are dominant, theoretical magnetic fluxes fail to reveal the universal law for l-PMS stars that enter late Henyey tracks. Altogether we emerge with a few lines of evidence suggesting that the transition from the turbulent to solar-type dynamo occurs at the later stages of l-PMS evolution as stars approach the zero-age main sequence. [ABSTRACT FROM AUTHOR]

The introduction of the notion of energy change resulting from the ion exchange in apatites leads to the question: how can some simple isomorphic series be described using the mentioned idea? We concentrated on the simple isomorphic series of compounds: apatite, bioapatite, calcite, aragonite, celestine, K-, Zn- and Cu-Tutton's salts. It was demonstrated in all the series, except Tutton's salts, that the change in energy and the change in the crystal cell volume are, in a simple way, dependent on the change in the ionic radii of the introduced ions. The linear relationships between the variations in energy and in the universal crystallographic dimension d were derived from the earlier equations and proven based on available data. In many cases, except the Tutton's salts, linear dependence was discovered between the change in energy and the sinus of universal angle Θ, corresponding to the change in momentum transfer. In the same cases, linear dependencies were observed between the energy changes and the changes in the volumes of crystallographic cells, and mutually between changes in the crystallographic cell volume V, crystallographic dimension d, and diffraction angle Θ. [ABSTRACT FROM AUTHOR]

This study investigated the optimal energy harvesting conditions of an oscillating wing with a trailing edge flap for various parameters such as flap length and maximum wing and flap pitch angles. Numerical simulations were performed for flap lengths ranging from 20 % to 70 % of the chord length (c). The maximum wing pitch angle varied from 40° to 75°, whereas the maximum flap pitch angle varied from 15° to 60°. Results show that the power output performance of a large flap is higher than that of a short flap. This is because the incoming fluid is deflected relatively more vertically by a large flap than by a short flap at the same maximum wing and flap pitch angles. Consequently, the momentum change is enhanced in the direction of the heaving motion, which eventually improves the power output performance. In addition, the camber of the wing increases with flap length, leading to an increase in incoming fluid velocity on the leeward surface of the wing. This caused a decrease in leeward surface pressure for large flaps, resulting in an increased pressure difference on the wing surfaces, which assisted in enhancing the heaving force and power. The maximum power output was obtained at a maximum wing pitch angle of 70° for a flap length 20 % of c, and it was reduced to 45° for a flap length 70 % of c. However, the optimum maximum flap pitch angle varied between 35° and 45° for varying flap lengths. The power output and efficiency were improved by around 27 % and 21 %, respectively, compared with an oscillating wing without a flap, and this was achieved for a flap length 60 % of c with the maximum wing and flap pitch angles of 50° and 45°, respectively. [ABSTRACT FROM AUTHOR]

Constraining the physical and chemical structure of young embedded disks is crucial for understanding the earliest stages of planet formation. As part of the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter Array Large Program, we present high spatial resolution (∼0.″1 or ∼15 au) observations of the 1.3 mm continuum and 13CO J = 2–1, C18O J = 2–1, and SO J N = 65–54 molecular lines toward the disk around the Class I protostar L1489 IRS. The continuum emission shows a ring-like structure at 56 au from the central protostar and tenuous, optically thin emission extending beyond ∼300 au. The 13CO emission traces the warm disk surface, while the C18O emission originates from near the disk midplane. The coincidence of the radial emission peak of C18O with the dust ring may indicate a gap-ring structure in the gaseous disk as well. The SO emission shows a highly complex distribution, including a compact, prominent component at ≲30 au, which is likely to originate from thermally sublimated SO molecules. The compact SO emission also shows a velocity gradient along a direction tilted slightly (∼15°) with respect to the major axis of the dust disk, which we interpret as an inner warped disk in addition to the warp around ∼200 au suggested by previous work. These warped structures may be formed by a planet or companion with an inclined orbit, or by a gradual change in the angular momentum axis during gas infall. [ABSTRACT FROM AUTHOR]

CoPS3 stands out in the family of the van der Waals antiferromagnets XPS3 (X = Mn, Ni, Fe, and Co) due to the unquenched orbital momentum of the magnetic Co2+ ions, which is known to facilitate the coupling of spins to both electromagnetic waves and lattice vibrations. Here, using a time-resolved magneto-optical pump–probe technique, we experimentally study the ultrafast laser-induced dynamics of mutually correlated spins and lattice. It is shown that a femtosecond laser pulse acts as an ultrafast heater and, thus, results in the melting of the antiferromagnetic order. At the same time, the resonant pumping of the 4T1g → 4T2g electronic transition in Co2+ ions effectively changes their orbital momentum, giving rise to a mechanical force that moves the ions in the direction parallel to the orientation of their spins, thus generating a coherent Bg phonon mode at the frequency of about 4.7 THz. [ABSTRACT FROM AUTHOR]

Euler's equation relates the change in angular momentum of a rigid body to the applied torque. This paper uses Lagrangian dynamics to derive Euler's equation in terms of generalized coordinates. This is done by parameterizing the angular velocity vector in terms of 3-2-1 and 3-1-3 Euler angles as well as Euler parameters, that is, quaternions. This paper fills a gap in the literature by using generalized coordinates to parameterize the angular velocity vector and thereby transform the dynamics obtained from Lagrangian dynamics into Euler's equation for rigid-body rotation. [ABSTRACT FROM AUTHOR]

Appreciative intelligence is the ability to identify the qualities and positive aspects of a person, and to harness them. In this article the concept of appreciative intelligence is analyzed, the relationship between this concept and appreciative inquiry is highlighted, syntheses are made regarding the connection of appreciative intelligence with other types of intelligence, such as emotional intelligence and adaptive intelligence. In the educational field, the appreciative intelligence of the teacher consists of essential components of different approaches: appreciative inquiry (research), appreciative advising, and appreciative analytical mindset. Appreciative inquiry represents the process of optimizing success within the educational institution, through appreciative methods. Appreciative advising provides a framework of improvement of communication process between students and teacher and supporting students in order to achieve the desired results. Appreciative analytical mindset defined as a thinking system focused on searching for the best aspects of a person. The article describes the concept of appreciative intelligence, being presented different acceptances and opinions of the researchers. Appreciative intelligence is the ability to see the generative potential in any situation and actualize it. Teachers with high appreciative intelligence are able to visualize and create small sequential steps that build on each other, creating momentum for changing the behavior of students, which results in positive outcomes. Appreciation is defined as a self-explanatory behavioral construct of goodwill that brings positive influences over time in the teaching-learning-assessment process. [ABSTRACT FROM AUTHOR]

Walking is more difficult for transtibial prosthesis users, partly due to a lack of calf muscle function. Powered ankle prostheses can partially restore calf muscle function, specifically push-off power from the soleus. But one limitation of a powered ankle is that emulating the soleus does not restore the multi-articular function of the gastrocnemius. This missing function may explain elevated hip and knee muscle demands observed in individuals walking on powered ankles. These elevated demands can make walking more fatiguing and impact mobility. Adding an Artificial Gastrocnemius to a powered ankle might improve gait for prosthesis users by reducing the prosthesis-side hip and knee demands. This work investigates if an Artificial Gastrocnemius reduced prosthesis-side hip or knee demands for individuals walking with a powered ankle providing high levels of push-off. We performed two case series studies that examined the effects that a passive elastic Artificial Gastrocnemius has on joint moment-impulses when prosthesis users walked with a powered ankle. We found that hip moment-impulse was reduced during stance when walking with an Artificial Gastrocnemius for six of seven participants. The Artificial Gastrocnemius effects on knee kinetics were variable and subject-specific, but in general, it did not reduce the knee flexor or extensor demands. The Artificial Gastrocnemius should be further explored to determine if reduced hip demands improve mobility or the user's quality of life by increasing the distance they can walk, increasing walking economy, or leading to increased physical activity or community engagement. [ABSTRACT FROM AUTHOR]

This paper presents a real-time relative three-axis attitude estimation using a camera and two gyros under momentum changes during close-proximity operations. The camera sensor provides quaternion measurements that relate the body frame of the deputy spacecraft with respect to the body frame of the chief spacecraft. The quaternion measurements are coupled with gyro measurements and attitude dynamics model in a multiplicative extended Kalman filter to determine relative attitude and gyro biases under momentum changes. The relative quaternion kinematics is augmented with spacecraft relative motion dynamics to represent the filter process dynamics. The quaternion measurements from a camera sensor and inertial measurement units (IMU) are utilized to the filter measurement model. The fault-tolerant attitude controller actuated by four reaction wheels, which has no unwinding problem is used for attitude tracking maneuvers during close-proximity operations in the presence of external disturbances, uncertain inertia parameter and actuator faults. This controller is combined with the extended Kalman filter to filter noisy measurements and to estimate gyro biases, which leads to a full-state feedback control system. Numerical simulations are performed to verify the effectiveness of the attitude estimation and control systems of the spacecraft with four reaction wheels during close-proximity operations of spacecraft in low-Earth orbit. [ABSTRACT FROM AUTHOR]

The effects of a trailing-edge active controlled flap on the power output performance of an oscillating wing energy harvester were investigated by numerical analysis. The overset mesh technique was adopted, and a structured mesh was used to simulate multiple moving bodies in close proximity to a wall to improve the accuracy. Sinusoidal motion was applied to both the wings and flaps. The maximum pitch angles for the wing and flap were varied to determine the optimum operating conditions. Numerical results show that the attachment of a flap onto an oscillating wing deflects the incoming flow in flap's direction and increases the vertical momentum change, which consequently increases the pushing force and power. The wing and flap maximum pitch angles significantly affect the power output of the energy harvester. The maximum power output is obtained at maximum pitch angles of 70° and 35° for the wing and flap, respectively. The maximum power is enhanced by 11 % when the flap length is 20 % of the chord length, as compared with the optimum condition of an oscillating wing without a flap. [ABSTRACT FROM AUTHOR]