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Non-reciprocal (NR) effective interactions violating Newton's third law occur in many biological systems, but can also be engineered in synthetic, colloidal systems. Recent research has shown that such NR interactions can have tremendous effects on the overall collective behavior and pattern formation, but can also influence aggregation processes on the particle scale. Here, we focus on the impact of non-reciprocity on the self-assembly of a colloidal system (originally passive) with anisotropic interactions whose character is tunable by external fields. In the absence of non-reciprocity, that is, under equilibrium conditions, the colloids form square-like and hexagonal aggregates with extremely long lifetimes yet no large-scale phase separation [Kogler et al., Soft Matter 11, 7356 (2015)], indicating kinetic trapping. Here, we study, based on Brownian dynamics simulations in 2D, an NR version of this model consisting of two species with reciprocal isotropic, but NR anisotropic interactions. We find that NR induces an effective propulsion of particle pairs and small aggregates ("active colloidal molecules") forming at the initial stages of self-assembly, an indication of the NR-induced non-equilibrium. The shape and stability of these initial clusters strongly depend on the degree of anisotropy. At longer times, we find, for weak NR interactions, large (even system-spanning) clusters where single particles can escape and enter at the boundaries, in stark contrast to the small rigid aggregates appearing at the same time in the passive case. In this sense, weak NR shortcuts the aggregation. Increasing the degree of NR (and thus, propulsion), we even observe large-scale phase separation if the interactions are weakly anisotropic. In contrast, systems with strong NR and anisotropy remain essentially disordered. Overall, the NR interactions are shown to destabilize the rigid aggregates interrupting self-assembly and phase separation in the passive case, thereby helping the system to overcome kinetic barriers. [ABSTRACT FROM AUTHOR]

Newton's laws of motion and Newtonian conservation principles such as those for energy and momentum involve the assumption that the vanishing of a certain total time derivative, on integration, yields a fixed constant value as an immediate consequence. While this may ultimately be the case for additional reasons, it is possible to have a properly vanishing total time derivative and yet the individual partial derivates are non-zero. Here, for a particular problem and based only on the requirement that the total time derivative of the quantity vanishes, we investigate the particular mechanism leading to a conventional conservation principle. For the energy and angular momentum totals for planar steady orbiting motion, the partial differential conditions may be formally solved to obtain the general solutions. We determine the general structure for variable energy and angular momentum for which the total time derivatives vanish, and from which it is apparent that the standard expression for constant energy and angular momentum is recovered. [ABSTRACT FROM AUTHOR]

The article discusses the controversy surrounding joint replacement surgery for patients with obesity, highlighting the differing perspectives of patients and surgeons. Patients emphasize their symptoms and disability, while surgeons point to higher risks associated with obesity. The disagreement arises from incomplete perspectives, with surgery being indicated when the expected utility post-treatment exceeds the status quo. The article suggests establishing specialized centers for joint replacements in obese patients to address systemic barriers and ensure appropriate care. The proposal aims to reconfigure incentives and increase supply to meet the demand for surgery. [Extracted from the article]

The article explores the metabolism of dinosaurs, particularly when running at maximum speed, by connecting their metabolism with kinetic energy. The methodology developed allows students to determine the maximum metabolism of dinosaurs, such as the Velociraptor, running at their fastest. The study provides insights into the lives of dinosaurs and engages students in understanding the complex relationship between metabolism, body mass, and locomotion speed. The research highlights the importance of considering the metabolic rates of animals when studying their locomotion and energy expenditure. [Extracted from the article]

This paper aims to describe and analyze a relativistic engine that uses a permanent magnet and an electrically charged device. This is a novel device that was not described before. According to Newton's third law, every action is met with an equal and opposite reaction, meaning the total force in a system unaffected by external forces is zero. However, relativity principles state that signals cannot travel faster than the speed of light, so actions and reactions cannot occur simultaneously. As a result, the total force cannot be zero at any given moment. This implies that the system gains mechanical momentum and energy over a finite period. The question then arises about how to uphold the law of momentum and energy conservation. It has been shown that momentum is balanced by an equal and opposite momentum in the field, while the energy gained by the engine is offset by a reduction in the field's energy. Previous analyses assumed that the bodies involved were macroscopically neutral, meaning the number of electrons and ions was equal in every volume element. This paper relaxes that assumption and examines charged bodies interacting with magnetic currents from permanent magnetic materials, exploring the implications for a charged relativistic engine based on a permanent magnet. [ABSTRACT FROM AUTHOR]

The article in the Journal of Fluid Mechanics delves into the impact of fluid viscoelasticity on ultrasound-induced particle transport in microfluidics. Through a combination of theoretical, numerical, and experimental approaches, the study examines how viscoelastic parameters affect acoustic energy density (AED) and particle migration dynamics. The research indicates that increasing fluid elasticity speeds up particle migration, while higher viscosity slows it down. This investigation aims to enhance our comprehension of particle migration in viscoelastic fluids under ultrasound, potentially influencing future studies on particle/cell movement in bio-fluids. [Extracted from the article]

The article delves into the phenomenon of delayed gravitational collapse in colloidal suspensions, specifically focusing on the resistance of colloidal gels to gravity. Through theoretical modeling, the study examines the delay time, which determines the shelf life of gel-based products, and sedimentation behavior. Factors such as initial volume fraction and particle interactions play a crucial role in understanding the collapse behavior of colloidal gels under gravitational forces. The research sheds light on the time evolution of sedimenting gels, density profiles, colloidal flux, and volume fractions, revealing distinct regimes of delay, linear settling, and exponential compaction. The study underscores the significance of dilatational viscosity and local density variations in comprehending the dynamics of colloidal gels under gravity, suggesting potential modifications to the model for better alignment with experimental findings and advocating for further research to incorporate erosion mechanisms and higher dimensions for a more holistic understanding of colloidal gel behavior. [Extracted from the article]

The dynamics of China's regional innovation in the process of deep integration between industry, university, and research institutes is in a constant state of flux, exhibiting various characteristics such as fluctuations and shifts. This study aims to assess the development status of China's regional industry-university research institute cooperation network from the perspective of change speed, utilising catastrophe series theory and methods such as butterfly catastrophe, dovetail catastrophe, and cusp catastrophe. Through a static time series panel evaluation, the study captures the static change speed value and trend value of the deep integration of China's regional industry-university research institute cooperation network. Drawing on Newton's second law of motion in physics as a reference, a comprehensive evaluation value is derived, reflecting the actual development status of China's regional industry-university research institute cooperation network from the perspective of change speed. [ABSTRACT FROM AUTHOR]

The article discusses the development of highly sensitive, selective, and stable palladium-based MEMS gas sensors for hydrogen energy security. It highlights the challenges posed by hydrogen's properties and the need for accurate monitoring due to safety concerns. The text explores innovative strategies such as ultrathin bimetallic Pd alloy NW arrays, tandem-layered hybrid matrix separation membranes, single-cantilever chip design, mechanism decoupling via multiscale simulation, and multiplexed sensing arrays with intelligent algorithms to enhance the performance of Pd-based MEMS hydrogen sensors. The authors emphasize the importance of a multidisciplinary approach to unlock the full potential of these sensors and accelerate the transition to a clean, hydrogen-powered future. [Extracted from the article]

In a previous work, we showed that Newton's third law does not strictly hold in a system with remote elements due the finite speed of signal propagation, and thus force imbalance occurs at the system's center of mass. As the said system is affected by a total force for a finite time interval, mechanical energy and momentum are gained by the system. In early works, we assumed that the bodies were macroscopically charge-neutral. Later, we removed this restriction, thus analyzing the consequences of a possible electrically charged relativistic motor. In the first published paper on this subject, we studied this phenomenon in general but gave only an example of a system reaching a stationary state. In this paper, we shall analyze a charged retarded electromagnetic motor in a more general time-dependent setting, giving specific examples in which the system never reaches a stationary state yet produces steady linear momentum nonetheless. We show that the device is more efficient in the microwave (or higher) frequencies. [ABSTRACT FROM AUTHOR]

Fluid–structure interaction (FSI) is ubiquitous in various engineering disciplines, and effectively managing FSI often appears to be the key for successful failure analysis and safety-oriented design. Smoothed particle hydrodynamics (SPH) serves as a potent nonlocal meshfree method for fluid dynamics modeling, while peridynamics (PD) demonstrates exceptional capability in addressing structural dynamics involving large deformations and discontinuities. Thus, leveraging their respective strengths in a combined approach holds significant promise for tackling FSI challenges. In this work, we propose a new peridynamics–smoothed particle hydrodynamics (PD-SPH) coupling model for addressing FSI. A stable and efficient coupling algorithm for data transfer between PD and SPH is put forward. In this coupling strategy, a PD particle directly participates in solving the SPH governing equations when it is identified to be within the support domain of an SPH particle. This can be done since the SPH quantities including the density, velocity, and pressure of a PD particle are naturally attainable within the framework of non-ordinary state-based peridynamics theory. Concurrently, in solving PD governing equations, reaction forces from SPH particles act as external forces for PD particles, determined straightforwardly through Newton's third law. As such, the proposed PD-SPH coupling strategy is straightforward to implement and offers high computational efficiency. Validation examples demonstrate that the proposed PD-SPH coupling model is computationally robust and adept at capturing physical phenomena in diverse FSI scenarios involving breaking free surfaces of fluid and large structural deformations of solid. Moreover, the proposed PD-SPH coupling model is flexible introducing no constraint conditions for applications and can accommodate different particle resolutions for PD and SPH domains. These features enable a broad application range of the proposed PD-SPH coupling model including simulations of explosion-induced soil fragmentation, rock fracture, and concrete dam failure, which will be conducted by authors in the near future. [ABSTRACT FROM AUTHOR]

ABSTRACT Most soils and rocks contain varying fractions of clay minerals within their solid matrix. These geomaterials can exhibit a significant swelling potential toward chemo‐thermo‐hydromechanical loadings. Several multiscale modeling techniques have been developed to ascertain their swelling behavior across various scales, with molecular dynamics (MD), micromechanics‐based approaches, and double‐porosity models being the most common. MD simulation is a computational technique that applies Newton's second law of motion to depict the movement of particles within a granular system. Micromechanics‐based approaches upscale the poro‐elasticity law from the clay layer level to the sample scale through homogenization. Dual‐porosity models are generally based on elasto‐plasticity, incorporating different hydro‐mechanical laws at two distinct scales. These models have been extensively used, particularly for clayey soils and bentonites, though their application to clayey rocks has not been reported in the literature. Although their significant contribution to the understanding of clay swelling behavior, these techniques have been insufficiently reviewed, compared, and discussed mutually in the literature. This paper aims to provide a cross‐look on these multiscale approaches by presenting the theoretical background of existing formulations, highlighting breakthrough results, discussing major differences and current challenges, and proposing future perspectives. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAVs) have seen a rise in use during the last few years. Such aircrafts are now a convenient way to complete dangerous, dirty, and tedious tasks. Given that their operation involves a control problem which is non-linear and coupled, it is difficult to analyse. This paper presents the modeling and control of a fixed-wing unmanned aircraft as a contribution to this field. The system's flight dynamics is derived using Newton's second law of motion. The system is designed to have a non-linear Proportional Integral Derivative (NPID) controller and a higher-order sliding mode controller (HOSMC). When simulating the system using MATLAB Simulink software, an external disturbance was added to test the robustness of the controllers. Five performance indices which include mean square error (MSE), integral time square error (ITSE), integral absolute error (IAE), integral time absolute error (ITAE), and integral square error (ISE), were used to compare the controllers performance. These indices are used to provide a numerical assessment of the two controllers' performance. The outcomes demonstrate that the roll, pitch, and yaw states performed better than the super-twisting sliding mode controller. On the airspeed control, the non-linear PID performed better than the super-twisting sliding mode controller. [ABSTRACT FROM AUTHOR]

Thermodynamics is a fundamental topic of continuum mechanics and biomechanics, with a wide range of applications to physiological and biological processes. This study addresses two fundamental limitations of current thermodynamic treatments. First, thermodynamics tables distributed online by the U.S. National Institute of Standards and Technology (NIST) report properties of fluids as a function of absolute temperature T and absolute pressure P. These properties include mass density p, specific internal energy u, enthalpy h = u + P/p, and entropy s. However, formulations of jump conditions across phase boundaries derived from Newton's second law of motion and the first law of thermodynamics employ the gauge pressure p = P - Pr, where P, is an arbitrarily selected referential absolute pressure. Interchanging p with P is not innocuous as it alters tabulated NIST values for u while keeping h and s unchanged. Using p for functions of state and governing equations solves the problem with using NIST entries for the specific internal energy u in standard thermodynamics tables and analyses of phase transformation in continuum mechanics. Second, constitutive models for the free energy of fluids, such as water and air, are not typically provided in standard thermodynamics treatments. This study proposes a set of constitutive models and validates them against suitably modified NIST data. [ABSTRACT FROM AUTHOR]

This study investigates the performance of GPT-4, an advanced AI model developed by OpenAI, on the force concept inventory (FCI) to evaluate its accuracy, reasoning patterns, and the occurrence of false positives and false negatives. GPT-4 was tasked with answering the FCI questions across multiple sessions. Key findings include GPT-4's proficiency in several FCI items, particularly those related to Newton's third law, achieving perfect scores on many items. However, it struggled significantly with questions involving the interpretation of figures and spatial reasoning, resulting in a higher occurrence of false negatives where the reasoning was correct, but the answers were incorrect. Additionally, GPT-4 displayed several conceptual errors, such as misunderstanding the effect of friction and retaining the outdated impetus theory of motion. The study's findings emphasize the importance of refining AI-driven tools to make them more effective in educational settings. Addressing both AI limitations and common misconceptions in physics can lead to improved educational outcomes. [ABSTRACT FROM AUTHOR]

The article "Particle chirality does not matter in the large-scale features of strong turbulence" explores the behavior of chiral particles in turbulent flows through numerical simulations. The research indicates that particle chirality does not significantly affect the large-scale features of the flow as turbulence strengthens, with falling particles becoming less influential. The study also compares the collision behaviors of chiral particles and spheres, revealing differences in their interactions. Overall, the findings offer valuable insights into the dynamics of chiral particles in homogeneous isotropic turbulence, emphasizing the need for further research in this area. [Extracted from the article]

This research proposes an analytical solution of the nano-concrete-epoxy interaction area within nano crack region of the reinforced concrete beam by applying Newton's third law in static equilibrium. For deriving the governing equation, the imaginary beam with free ends (no support) is considered within nano crack region. This imaginary beam is acted along the imaginary line of concrete-epoxy interface. Newton's third law is applicable for deriving the governing equation because of assuming the absence of frictional and other external forces. The parametric study is performed for implementing the proposed formula of nano interactive area considering variable nano crack depths and thicknesses. The nano interactive area is increased gradually with the increment of depths and thicknesses based on the parametric study because of linear functionality of interactive area and geometry of nano crack region. The maximum interactive area is found to be 314 nm2 at 0.6 ratio of depths and thicknesses of the nano crack. The incremental differences in interactive area between the crack depth or thickness ratios of 0.1 and 0.6 are found to be 25.4% and 1.6% for variations of the crack depth and thickness ratios, respectively. So, the crack depth shows higher impact on the interaction area compared to the thickness of the crack. However, there is a scope for enhancing this research in future by deriving closed-formed analytical formulations to consider appropriate boundary conditions. [ABSTRACT FROM AUTHOR]

The given text discusses different approaches to finding equations of motion for physical systems, such as the Newtonian, Lagrangian, and Hamiltonian approaches. It presents a supplementary tool using the total differential of the mechanical energy function to obtain equations of motion for certain systems. The text also explores the relationship between this approach and Hamilton's equations of motion. Additionally, the text provides concise and factual information about different types of motion and their corresponding equations. [Extracted from the article]

This article discusses the use of 3D camera systems and accompanying software in physics instruction. The authors describe a Python program that can track and analyze the momentum of a midair collision between two playground balls. The program is freely available for instructors and can be used in student lab settings or as an instructor-led exercise. The article provides detailed information on the camera system used, the data collection and analysis process, and the results obtained. The authors conclude that the use of 3D cameras and tracking software expands the possibilities for physics experiments and enhances students' understanding of complex systems. [Extracted from the article]

Ojhung is one of the indigenous Indonesian cultures from Sumenep Regency which contains relevant science concepts to be applied in science learning. Therefore, this research aimed to identify and explore the concepts of science contained in the Ojhung tradition while evaluating their relevance to the Merdeka or national curriculum. This research uses a qualitative design with a grounded theory based on scientific concepts in the Ojhung tradition and can be applied in science learning. The concepts of science that have been successfully explored and identified are Newton's Third Law, Sound Waves, Sense of Hearing, Pressure, Flexibility, Body Muscles, Moments of Inertia, and Skin Wounds. All concepts that have been explored can actualise learning outcomes in the Merdeka Curriculum. This research implies applying science concepts to Ojhung to improve public scientific literacy and science learning in schools. [ABSTRACT FROM AUTHOR]

Phenomena-driven instruction is an effective method for addressing science misconceptions. Research has shown that simply teaching correct information does not automatically remove misconceptions, as students often revert back to their prior thinking. To create a permanent change in students' thinking, misconceptions must be directly addressed. Phenomena, which are real-world events or situations, can be used as teaching tools to engage students and help them develop a deeper understanding of concepts. By encountering phenomena that contradict their misconceptions, students can correct their thinking and gain a better understanding of scientific principles. [Extracted from the article]

The article discusses the dynamics of a spring-rod system in physics education, focusing on the period of angular oscillations when the rod is pivoted at different positions. It highlights the challenges students face in understanding rotational dynamics and the tendency to memorize solutions rather than grasp the underlying concepts. The analysis reveals a coincidence in the period of oscillation when the rod is pivoted at the midpoint or endpoint, showcasing the impact of moment of inertia and torque on the system. The study suggests that exploring this coincidence can enhance students' understanding of rotational motion in introductory physics courses. [Extracted from the article]

The article "Sauntering Sauropods: The Preferred Walking Speeds of the Largest Land Animals That Ever Lived" explores the methodology of calculating the walking speed of sauropod dinosaurs using physics principles. By applying the inverted pendulum model to humans, horses, and elephants, the study finds that sauropods walked at speeds similar to modern animals. The research delves into the anatomy and locomotion of sauropods like Diplodocus, Brachiosaurus, and Argentinosaurus, revealing that these massive dinosaurs walked at comparable speeds to present-day animals. The study highlights the interdisciplinary nature of science by combining kinematics, Newton's laws, and simple harmonic motion to predict the walking speeds of sauropods. [Extracted from the article]

Newton's third law, action = reaction, is a foundational statement of classical mechanics. However, in natural and living systems, this law appears to be routinely violated for constituents interacting in a nonequilibrium environment. Here, we use computer simulations to explore the macroscopic phase behavior implications of breaking microscopic interaction reciprocity for a simple model system. We consider a binary mixture of attractive particles and introduce a parameter that is a continuous measure of the degree to which interaction reciprocity is broken. In the reciprocal limit, the species are indistinguishable, and the system phase separates into domains with distinct densities and identical compositions. Increasing nonreciprocity is found to drive the system to explore a rich assortment of phases, including phases with strong composition asymmetries and three-phase coexistence. Many of the states induced by these forces, including traveling crystals and liquids, have no equilibrium analogs. By mapping the complete phase diagram for this model system and characterizing these unique phases, our findings offer a concrete path forward toward understanding how nonreciprocity shapes the structures found in living systems and how this might be leveraged in the design of synthetic materials. [ABSTRACT FROM AUTHOR]

Considering the harsh environment of the port, automated straddle carriers, characterized by their large size, tall frame, and high center of gravity, may experience instability during steering and transportation due to inaccurate state estimation. Thus, this paper explores state estimation techniques for automated straddle carriers utilizing smart sensors which are capable of data measurement and processing. First, using the steering principles and lateral characteristics of automated straddle carriers, a dynamic linear model is established based on Newton's second law of motion. Then, in order to enhance the reliability and flexibility of state estimation, a distributed smart sensor network structure is introduced. In addition, considering the challenge of unknown-but-bounded noise and the precision demands of the considered automated straddle carrier, a modified distributed set-membership estimation algorithm is proposed and is derived sufficient conditions for the existence of the estimation set for the considered automated straddle carriers. Finally, the effectiveness and superiority of the proposed method are demonstrated by performance analyses. [ABSTRACT FROM AUTHOR]

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This document is a compilation of various scientific papers and preprints covering a wide range of topics, including protein folding, cell migration, machine learning, deep neural networks, neural scaling laws, representations and generalization in artificial and brain neural networks, and the neuron as a direct data-driven controller. The papers discuss different aspects of these subjects, providing a comprehensive overview of the current research in these fields. This document can be a valuable resource particularly in the fields of neuroscience and artificial intelligence. [Extracted from the article]

Very recently, a straightforward method was proposed to understand galaxies and galactic clusters without using the very elusive dark matter concept. This method is called the κ -model. The main idea is to maintain the form of the usual physical laws, especially Newton's laws of motion when gravity is weak, but only by applying a local scaling procedure for the related lengths, distances, and velocities. This local scaling appears as a correspondence principle in the κ -model. In this model, the fundamental physical constants remain universal, i.e., they are independent of a point in space and of time. The κ -model is Newtonian in its essence, but there is a relativistic extension that can easily be built. The aim of the present paper is to detail the mathematical formalism supporting it. [ABSTRACT FROM AUTHOR]

This article discusses the technological progress that has been made in the field of wheels and tires. It explains the evolution of wheels from wooden spokes to carbon fiber, and the transition from spoked wheels to solid wheels with hubcaps. The article also explores the development of pneumatic air-filled tires and the dangers of blowouts. It includes a class project idea for students to compare the pressure exerted by a tire on the road with the air pressure inside the tire. The article concludes with a discussion on the rotational motion of wheels and the concept of simulated gravity in rotating habitats. [Extracted from the article]

This article explores the journey of Olympic swimmers and the challenges they face in reaching the top of their sport. It emphasizes the dedication and sacrifices required, as well as the intense competition at the Olympic trials. The article also discusses how mathematics, physics, and technology have revolutionized swimming training, allowing coaches to tailor methods to individual athletes. It further examines the advancements in technology, nutrition, and biomechanics that have contributed to improved performances in Olympic sports over the past century. The article concludes by discussing changes in swimming techniques and the impact of materials science on swimwear. It also highlights the use of physics and mathematical modeling to enhance the training of elite swimmers, including the creation of "digital twins" to analyze and improve performance. The text concludes by reflecting on the impact of technology on the Olympics and the redefinition of human limits. [Extracted from the article]

The article discusses the relevance and importance of teaching physics as the study of nature's rules. The author shares personal experiences and insights into teaching physics, emphasizing the need for critical thinking skills and the appreciation of physics as an awe-inspiring subject. The article also highlights the use of questions and equations in teaching physics, as well as the significance of concepts such as Newton's second law and Einstein's equation. The author encourages educators to make science courses flavorful and awesome to engage students. [Extracted from the article]