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Definition: This entry first provides an overview of the historical, cultural and epistemological background that is key for Hamilton's positions on mechanics. We consider the investigations on geometrical optics in the 17th and 18th centuries, Euler's and Lagrange's foundations of variational calculus in the 18th century to find extrema of physical quantities expressed as infinite sums of infinitesimals (today, we would say 'definite integrals'), and Lagrange's introduction of a revolutionary analytical mechanics, all of which are all fertile grounds for Hamilton's steps—first, in what we could call analytical optics, then in an advanced form of analytical mechanics. Having provided such an overview, we run through some of Hamilton's original papers to highlight how he posed his principle(s) in the wake of his forerunners and how his principles are linked with the search for a unitary view of physics. [ABSTRACT FROM AUTHOR]

We follow the Boltzmann-Clausius-Maxwell (BCM) proposal to establish the generalized second law (GSL) that is applicable to a system of any size, including a single particle system as our example establishes, and that supercedes the celebrated second law (SL) of increase of entropy of an isolated system. It is merely a consequence of the mechanical equilibrium (stable or unstable) principle (Mec-EQ-P) of analytical mechanics and the first law. We justify an irreversibility priciple that covers all processes, spontaneous or not, and having both positive and negative nonequilibrium temperatures temperatures T defined by (d Q / d S) E . Our novel approach to establish GSL/SL is the inverse of the one used in classical thermodynamics and clarifies the concept of spontaneous processes so that d S ≥ 0 for T > 0 and d S < 0 for T < 0 . Nonspontaneous processes such as creation of internal constraints are not covered by GSL/SL. Our demonstration establishes that Mec-EQ-P controls spontaneous processes, and that temperature (positive and negative) must be considered an integral part of dissipation. [ABSTRACT FROM AUTHOR]

In this paper, the fatigue resistance of a full-scale Steel Catenary Riser (SCR) girth weld is investigated using the Strength–Number of cycles (S–N) curve method based on weld formation quality and fracture mechanics approaches. The test results, presented in the form of S–N curves, are superior to the design curve E in BS 7608. Compared with the S–N curve determined by a resonant bending rig, the analytical fracture mechanics, i.e., engineering critical assessment (ECA) based on BS 7910, can provide a rational estimation of full-scale girth welds. For the numerical methods, the short crack growth phase is crucial to improving the accuracy and reliability of the assessment. For the girth weld with a concave root, the geometries of the weld cap are the predominant factors for fatigue life. Although the crack initiation site is always located at the outer surface regardless of the flushed or welded caps, the weld grinding treatment is still effective in promoting fatigue life. [ABSTRACT FROM AUTHOR]

We follow the Boltzmann-Clausius-Maxwell (BCM) proposal to establish the generalized second law (GSL) that is applicable to a system of any size, including a single particle system as our example establishes, and that supercedes the celebrated second law (SL) of increase of entropy of an isolated system. It is merely a consequence of the mechanical equilibrium (stable or unstable) principle (Mec-EQ-P) of analytical mechanics and the first law. We justify an irreversibility priciple that covers all processes, spontaneous or not, and having both positive and negative nonequilibrium temperatures temperatures T defined by (dQ/dS)E. Our novel approach to establish GSL/SL is the inverse of the one used in classical thermodynamics and clarifies the concept of spontaneous processes so that dS≥0 for T>0 and dS<0 for T<0. Nonspontaneous processes such as creation of internal constraints are not covered by GSL/SL. Our demonstration establishes that Mec-EQ-P controls spontaneous processes, and that temperature (positive and negative) must be considered an integral part of dissipation.

The D'Alembert–Lagrange principle is a fundamental concept in analytical mechanics that simplifies the analysis of multi-degree-of-freedom mechanical systems, facilitates the dynamic response prediction of structures under various loads, and enhances the control algorithms in robotics. It is essential for solving complex problems in engineering and robotics. This theoretical study aims to highlight the advantages of using acceleration energy to obtain the differential equations of motion and the generalized driving forces, compared to the classical approach based on the Lagrange equations of the second kind. It was considered a mechanical structure with two degrees of freedom (DOF), namely, a planar robot consisting of two homogeneous rods connected by rotational joints. Both the classical Lagrange approach and the acceleration energy model were applied. It was noticed that while both approaches yielded the same results, using acceleration energy requires only a single differentiation operation, whereas the classical approach involves three such operations to achieve the same results. Thus, applying the acceleration energy method involves fewer mathematical steps and simplifies the calculations. This demonstrates the efficiency and effectiveness of using acceleration energy in dynamic system analysis. By incorporating acceleration energy into the model, enhanced robustness and accuracy in predicting system behavior are achieved. [ABSTRACT FROM AUTHOR]

The Rossiter–McLaughlin effect measures the misalignment between a planet's orbital plane and its host star's rotation plane. Around 10 per cent of planets exhibit misalignments in the approximate range 80°–125°, with their origin remaining a mystery. On the other hand, large misalignments may be common in eccentric circumbinary systems due to misaligned discs undergoing polar alignment. If the binary subsequently merges, a polar circumbinary disc – along with any planets that form within it – may remain inclined near 90 |$^{\circ }$| to the merged star's rotation. To test this hypothesis, we present N -body simulations of the evolution of a polar circumbinary debris disc comprised of test particles around an eccentric binary during a binary merger that is induced by tidal dissipation. After the merger, the disc particles remain on near-polar orbits. Interaction of the binary with the polar-aligned gas disc may be required to bring the binary to the small separations that trigger the merger by tides. Our findings imply that planets forming in discs that are polar-aligned to the orbit of a high-eccentricity binary may, following the merger of the binary, provide a possible origin for the population of near-polar planets around single stars. [ABSTRACT FROM AUTHOR]

Managing novelty in perception-based human activity recognition (HAR) is critical in realistic settings to improve task performance over time and ensure solution generalization outside of prior seen samples. Novelty manifests in HAR as unseen samples, activities, objects, environments, and sensor changes, among other ways. Novelty may be task-relevant, such as a new class or new features, or task-irrelevant resulting in nuisance novelty, such as never before seen noise, blur, or distorted video recordings. To perform HAR optimally, algorithmic solutions must be tolerant to nuisance novelty, and learn over time in the face of novelty. This paper 1) formalizes the definition of novelty in HAR building upon the prior definition of novelty in classification tasks, 2) proposes an incremental open world learning (OWL) protocol and applies it to the Kinetics datasets to generate a new benchmark KOWL-718, 3) analyzes the performance of current stateof-the-art HAR models when novelty is introduced over time, 4) provides a containerized and packaged pipeline for reproducing the OWL protocol and for modifying for any future updates to Kinetics. The experimental analysis includes an ablation study of how the different models perform under various conditions as annotated by Kinetics-AVA. The code may be used to analyze different annotations and subsets of the Kinetics datasets in an incremental open world fashion, as well as be extended as further updates to Kinetics are released. [ABSTRACT FROM AUTHOR]

In this paper, we consider the long-term behavior of some special solutions to the Wave Kinetic Equation. This equation provides a mesoscopic description of wave systems interacting nonlinearly via the cubic NLS equation. Escobedo and Velázquez showed that, starting with initial data given by countably many Dirac masses, solutions remain a linear combination of countably many Dirac masses at all times. Moreover, there is convergence to a single Dirac mass at long times. The first goal of this paper is to give quantitative rates for the speed of said convergence. In order to study the optimality of the bounds we obtain, we introduce and analyze a toy model accounting only for the leading order quadratic interactions. [ABSTRACT FROM AUTHOR]

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Chlorophyll a fluorescence, a sensitive and cost-effective probe, is widely used in photosynthetic research. Its rapid phase, occurring within 1 second under intense illumination, displays complex O-J-I-P transients, providing valuable insights into various aspects of photosynthesis. In addition to employing experimental approaches to measure the rapid Fluorescence Induction (FI) kinetics, mathematical modeling serves as a crucial tool for understanding the underlying mechanisms that drive FI dynamics. However, the significant uncertainty and arbitrary nature of selecting model parameters amplify concerns about the effectiveness of modeling tools in aiding photosynthesis research. Therefore, there is a need to gain a deeper understanding of how these models operate and how arbitrary parameter choices may influence their outcomes. In this study, we employed the Morris method, a global Sensitivity Analysis (SA) tool, to assess the significance of rate constants employed in an existing fluorescence model, particularly those linked to the entire electron transport chain, in shaping the rapid FI dynamics. In summary, utilizing the insights gained from the Morris SA allows for targeted refinement of the photosynthesis model, thereby improving our understanding of the complex processes inherent in photosynthetic systems. [ABSTRACT FROM AUTHOR]

Gas hydrate plugs in petroleum fluid pipelines are a major flow assurance problem and thus, it is important for industry to have reliable mathematical models for estimating the time required to dissociate a hydrate pipeline plug. The existing mathematical models for modelling hydrate plug dissociation treat the problem as a pure heat transfer problem. However, an early study by Jamaluddin et al. speculated that the kinetics of gas hydrate dissociation could become the rate-limiting factor under certain operating conditions. In this short communication, a rigorous 2D model couples the equations of heat transfer and fluid flow with Clarke and Bishnoi's model for the kinetics of hydrate dissociation. A distinguishing feature of the current work is the ability to predict the shape of the dissociating hydrate–gas interface. The model is used to correlate experimental data for both sI and sII hydrate plug dissociation, via single-sided depressurization and double-sided depressurization. As a preliminary examination on the necessity of including dissociation kinetics, this work is limited to conditions for which hydrate dissociation rate constants are available; kinetic rate constants for hydrate dissociation are available at temperatures above 273.15 K. Over the range of conditions that were investigated, it was found that including the intrinsic kinetics of hydrate dissociation led to only a very small improvement in the accuracy of the predictions of the cumulative gas volumes collected during dissociation. By contrast, a sensitivity study showed that the predictions of hydrate plug dissociation are very sensitive to the value of the porosity. Thus, it is concluded that unless values of the thermophysical properties of a hydrate plug are known, accounting for the dissociation kinetics need not be a priority. [ABSTRACT FROM AUTHOR]

The SH2 domains of SHP2 play a crucial role in determining the function of the SHP2 protein. While the folding and binding properties of the isolated NSH2 and CSH2 domains have been extensively studied, there is limited information about the tandem SH2 domains. This study aims to elucidate the folding and binding kinetics of the NSH2-CSH2 tandem domains of SHP2 through rapid kinetic experiments, complementing existing data on the isolated domains. The results indicate that while the domains generally fold and unfold independently, acidic pH conditions induce complex scenarios involving the formation of a misfolded intermediate. Furthermore, a comparison of the binding kinetics of isolated NSH2 and CSH2 domains with the NSH2-CSH2 tandem domains, using peptides that mimic specific portions of Gab2, suggests a dynamic interplay between NSH2 and CSH2 in binding Gab2 that modulate the microscopic association rate constant of the binding reaction. These findings, discussed in the context of previous research on the NSH2 and CSH2 domains, enhance our understanding of the function of the SH2 domain tandem of SHP2. [ABSTRACT FROM AUTHOR]

This study delves into the mechanistic modelling of literature results for the adsorption of aqueous Pb(II) by metabolically inhibited bacterial cultures from the industrial sector. Employing a multi-compartmented mathematical model based on Langmuir's mechanistic multi-surface adsorption, the study explores the adsorption process onto multiple heterogeneous surfaces operating simultaneously. The mathematical model is elucidated, and its parameters are optimized using experimental data obtained from various biosorbents. The results highlight the efficacy of the proposed multi-surface Langmuir kinetic models in predicting the adsorption kinetics of Pb(II) for diverse adsorbents. The study underscores the potential of multi-surface Langmuir modelling in capturing surface heterogeneity. The sensitivity analysis reveals the models' responsiveness to variations in adsorption rate constants (kad), emphasizing the necessity of precise parameterization for robust predictions. These sensitivities have significant implications for the accurate modelling of Pb(II) adsorption kinetics, guiding advancements in effective wastewater treatment strategies. [ABSTRACT FROM AUTHOR]

In the face of growing environmental challenges and the urgent need for sustainable solutions, this research delves into an innovative approach to wastewater treatment by harnessing the power of agricultural waste materials as efficient adsorbents. The focuses on mitigating water pollution and bringing irrigation water quality in line with strict maximum permissible limits (MPLs). Initial assessments revealed elevated levels of contaminants, all exceeding MPLs. Among ten adsorbent materials tested, Rice Husk Ash (RHA), Sugarcane Bagasse (SB), and Ferric Oxide Sand (Fe-S), emerged as highly effective materials, achieving maximum reductions. Optimized conditions for adsorbent dosage, contact time, and wastewater load were identified which was 2.0 g of adsorbent, 250 mL of sewage water load at 15 min contact time. RHA demonstrated a remarkable 60-75% reduction in BOD, 52-67% in COD, and over 100% in RSC reduction. SB achieved reductions of 57-67% in BOD, 47-59% in COD, and 41-76% in RSC. Fe-S delivered significant reductions in COD (51-61%) and nearly 100% in RSC reduction. Kinetic studies confirmed pseudo-second-order kinetics as the dominant adsorption mechanism, with correlation coefficients (R²) exceeding 0.98, further supporting the effectiveness of these adsorbents. This research underscores the potential of agricultural waste-based adsorbents, especially RHA and SB, in treating sewage water pollutants and making it fit for irrigation. [ABSTRACT FROM AUTHOR]

This study aimed to determine the isotherm, kinetics, and thermodynamics of Remazol Yellow FG adsorption by ZnCl2-activated bamboo charcoal. The research began with preparing activated charcoal from bamboo stems using ZnCl2, and then the quality was characterized according to the SNI. The adsorption isotherms were tested against Langmuir and Freundlich models, and the kinetics were examined for pseudo-first and pseudo-second orders. The thermodynamic parameters, which were enthalpy (ΔH°), entropy(ΔS°), and free energy (ΔG°), were also determined. The results showed that the adsorption followed the Langmuir isotherm with the adsorption capacity of 45.4545 mg/g, and the kinetic model corresponded to the pseudo-second order. The values of ΔH°, ΔS°, and ΔG° using different concentrations of Remazol Yellow RG of 100 and 300 mg/L at the optimum conditions of contact time of 240 minutes, the temperature of 303K, and pH 2 were -99.768 and - 83.971 KJ/mol; - 0.302 and - 0.239 KJ/mol; -8.383 and -11.433 KJ/mol, respectively. The adsorption was exothermic (ΔH° < 0), followed by a decrease in entropy (ΔSo < 0), and the process was spontaneous (ΔG° < 0) and controlled by chemical adsorption. [ABSTRACT FROM AUTHOR]

Robotic Roller Forming (RRF) is a novel process using an articulated robotic manipulator that can bend Ultra-High Strength materials into thin-walled profiles. For high strength or difficult-to-form sheet materials, a laser can be employed to synchronously heat and soften the local material during RRF. The aim of RRF is to establish itself as a highly flexible process for rapid prototyping as well as for small batch production. However, in finished parts formed with different materials, a new defect that shapes the profile like that of a hook was observed. To overcome this defect and to improve the adaptability of the process, a new analytical model is suggested for the automatic calculation of the tool center point based on the given process parameters. The model was compared to the previous state, where the hook defect was noticeably reduced. Additionally, the control of the bend radius was studied, and the resulting bend radius diverged from the target radius by 0.04 mm (2.45%). Further, when examining the reproducibility, the same bend angles could be achieved as in previous experiments using the constant laser power density. Finally, the development of the bend allowance was studied in various experiments. The analytical model for RRF is a promising method for calculating tool placement and controlling the bend radius in a freeform environment. [ABSTRACT FROM AUTHOR]

Within the various approaches to organic waste handling, composting has been recognized as an acceptable method to valorize organic waste. Composting is an aerobic technique of microbial disruption of organic matter which results with compost as a final product. To guarantee the quality of the compost, key process factors (like the moisture content, temperature, pH, and carbon-to-nitrogen ratio) must be maintained. In order to optimize the process, nine composting trials using grape skins were conducted in the present study under various initial moisture content and air flow rate conditions over the course of 30 days. The processes were monitored through physicochemical variables and microbiological activity. Also, the kinetics of the organic matter degradation and microbial growth were investigated. Although the thermophile phase was only achieved in experiments 3 and 8, the important variables proved the efficiency of all nine composting processes. The organic carbon content and C/N ratio decreased after the 30 days of composting processes and a great color change was noticed too. The values for the germination index for all experiments were above 80%, which means that the final products are non-toxic for plants. Also, the greatest change in organic carbon content in was evident in experiment 3; it decreased from 71.57 to 57.31%. And consequently, the rate of degradation for that experiment was the highest, at 0.0093 1/day. Furthermore, the response surface methodology was used to identify optimal operating conditions for grape skin composting and the obtained conditions were 58.15% for the initial moisture content and 1.0625 L/min for the air flow rate. [ABSTRACT FROM AUTHOR]

Nanopatterned tribocharge can be generated on the surface of elastomers through their replica molding with nanotextured molds. Despite its vast application potential, the physical conditions enabling the phenomenon have not been clarified in the framework of analytical mechanics. Here, we explain the final tribocharge pattern by separately applying two models, namely cohesive zone failure and cumulative fracture energy, as a function of the mold nanotexture's aspect ratio. These models deepen our understanding of the triboelectrification phenomenon. [ABSTRACT FROM AUTHOR]

In recent years, global attention towards new energy has surged due to increasing energy demand and environmental concerns. Researchers have intensified their focus on new energy, leading to advancements in technologies like triboelectrification, which harnesses energy from the environment. The invention of the triboelectric nanogenerator (TENG) has led to new possibilities, with the rotary sliding TENG standing out for its superior performance. However, understanding its mechanical behavior remains a challenge, potentially leading to structural issues. This paper introduces a novel analytical mechanics model to analyze the mechanical performance of the stator of the rotary sliding TENG, offering a new analytical solution. The solution also presents an innovative approach to solving axisymmetric problems in elasticity theory since it challenges a traditional assumption that the stress function depends solely on the radial coordinate, proposing a new stress function to derive a more general solution, supplementing the classical approach in the theory of elasticity. Through the obtained solutions, the mechanical characteristics of the rotary sliding TENG during operation are analyzed. A clearer relationship between mechanical characteristics and electrical output is expected to provide a theoretical basis for the design of the rotary sliding TENG. [ABSTRACT FROM AUTHOR]

The present paper describes, in a theoretical fashion, a variational approach to formulate fourth-order dynamical systems on differentiable manifolds on the basis of the Hamilton–d'Alembert principle of analytic mechanics. The discussed approach relies on the introduction of a Lagrangian function that depends on the kinetic energy and the covariant acceleration energy, as well as a potential energy function that accounts for conservative forces. In addition, the present paper introduces the notion of Rayleigh differential form to account for non-conservative forces. The corresponding fourth-order equation of motion is derived, and an interpretation of the obtained terms is provided from a system and control theoretic viewpoint. A specific form of the Rayleigh differential form is introduced, which yields non-conservative forcing terms assimilable to linear friction and jerk-type friction. The general theoretical discussion is complemented by a brief excursus about the numerical simulation of the introduced differential model. [ABSTRACT FROM AUTHOR]

In this work, a two-dimensional computational fluid dynamic (CFD) model is developed to describe the drying process of a packed bed made of spherical particles. The volumetrical evaporation rate inside the bed is computed from the pressure difference between the particle surface and the airflow. By using the thermal equilibrium assumption, the heat conservation equation is derived. The CFD model is solved in the COMSOL Multiphysics environment. The obtained results indicate remarkable maldistributions of temperature and moisture content. These maldistributions can be explained by the impact of lateral edges on thermo-hydraulic behavior. Additionally, the impact of particle diameter, air velocity, and bed width on the spatial-temporal moisture content and temperature distribution is investigated. It shows that the CFD model can be simplified to the receding front drying model for a bed made of small particles. Furthermore, by changing the thermal boundary conditions at the lateral edges, the influence of the heating mode at the lateral edges on the drying behavior is explored. The results indicate that contact heating at the bed wall can help to accelerate the drying process significantly. [ABSTRACT FROM AUTHOR]

This study is dedicated to an investigation and comparison of the kinetics of the foam stability of protein foaming agents based on the hydrolysates of solid keratin. The work utilized ready-made hydrolysates based on sodium hydroxide and a mixture of sodium hydroxide with calcium hydroxide for the synthesis of foaming agents. The synthesis was carried out according to the author's methodology. Among the indicators studied were foam multiplication, foam specific weight, foam stability over time, and average foam stability reduction rate. Experiments were conducted with various concentrations and ratios of components at constant temperature, pressure, and pH values, as well as mixing speed, mixing time, and observation time. Itis hypothesized that protein foaming agents based on hydrolysates of solid keratin using a mixture of hydroxides will not be able to achieve optimal values in the kinetics of foam stability. In contrast, protein foaming agents based on hydrolysates of solid keratin using sodium hydroxide individually have high potential foaming properties and, consequently, good foam stability kinetics indicators. The results of this study may be useful in the development of new synthesis methods for protein foaming agents with optimal foaming properties or for improving those that already exist. The research itself and the products obtained during it—protein foaming agents—are mainly aimed at expanding the industrial sphere of human activity. This may also have practical applications in other areas, such as the food industry, cosmetology, medicine, and others. [ABSTRACT FROM AUTHOR]

Engineered nanoparticles (NPs) have the potential to revolutionize disease diagnostics and treatment. However, NP interactions with proteins in biological fluids complicate their in vivo control. These interactions often lead to the formation of protein coronas around the NP surface, shaping NP fate and behavior within biological systems. To harness the full potential of NPs in biomedical applications, it is therefore essential to gain a comprehensive understanding of their interactions with proteins. Within this context, it must be recognized that traditional equilibrium-based descriptions of NP–protein interactions, which encompass parameters like equilibrium binding affinity and corona composition, do not provide sufficient detail to predict NP behavior in vivo. This limitation arises because the open in vivo system is a nonequilibrium state characterized by constantly changing concentrations and dynamic regulation of biological processes. In light of these considerations, this review explores the kinetics and timescales of NP–protein interactions, discussing their relevance, fundamental concepts, measurement techniques, typical ranges of association and dissociation rate constants, and dynamics of protein corona formation and dissociation. The review concludes by outlining potential areas for further research and development in this field. [ABSTRACT FROM AUTHOR]

Background. The inefficiency of the forehand stroke technique often stems from suboptimal execution of an athlete's biomechanical movements. For a forehand stroke to be effective, each biomechanical component - the ankles, knees, hips, shoulders, and elbows - must function in an optimal manner. Disconnection of any of these elements can lead to ineffective technique. High speed, influenced by the racket speed at the point of impact, is a key indicator of a perfect forehand stroke. However, the challenge lies in the fact that an athlete's movement and ball impact cannot be accurately observed with the naked eye, necessitating specialized tools for analysis. Study purpose. The study aims to develop software that assists in predicting ball speed outcomes based on an athlete's biomechanical movement during a forehand stroke execution. Materials and methods. The research method employed R&D. Data collection techniques consisted of video recordings of athletes' forehand strokes, which were later analyzed using software that examines movement angles of 10 national athletes. Results. The results indicated the average angles of elbows = 106.23, shoulders = 153.62, hips = 165.33, knees = 167.63, ankles = 164.54; and ball speed = 199.41 cm/s. Conclusions. The conclusion drawn is that to execute an effective forehand stroke with good ball speed, a moment of inertia must occur at the point of impact. The athletes should bend their elbow slightly, thereby reducing rotational resistance and increasing the speed of the racket head. The ankles, hips, and shoulders must move in synchronization within a continuous coordination chain, thereby allowing the athlete to fully leverage kinetic chain. The flexion movement of the elbow during the forward swing step is more effective than the extension movement where the elbow is slightly bent, resulting in a perfect shot. [ABSTRACT FROM AUTHOR]

Background. Somatotyping in modern sports can be an important factor to be considered. Different studies have already taken the initial step to identify the sport-specific somatotypes for different games and sports. In contrast with the Kho-Kho game, some attempts have been made to identify somatotypes specific for these games. But there are only few studies that have been conducted, and various areas are still waiting to be explored. Study purpose. The present study aimed to identify the specific somatotypes of the kho-kho players. Additionally, this study also made an attempt to explore the important somatic traits that influence the somatotypes of the Kho-Kho players. Materials and methods. A total number of 74 players from six Kho-Kho teams that participated in East Zone Inter-University Tournament were purposively selected for the study. The anthropometric data collection was done according to the standard procedures given by ISAK (International Society for Advancement of Kinanthropometry). The statistical analysis was done by using MS Excel (2021) and SPSS'23. Results. The results of the study showed that most of the Kho-Kho players (90.6%) were possessing ectomorphic and mesomorphic dominant traits. There was also a significant difference found in ectomorphic and mesomorphic traits among the players possessing mesomorphic-ectomorph (p<0.05), ectomorphic-mesomorph (p<0.05) and ectomorph-mesomorph (p<0.05) somatotypes. Furthermore, the discriminant analysis also highlighted that attributes of ectomorphic traits (Discriminant coefficient = 1.168) and mesomorphic traits (Discriminant coefficient = 0.812) were important somatic traits for the Kho-Kho players. Overall, 88.6% of the original cases have been correctly represented by the discriminant analysis. Conclusions. The present study showed that Kho-Kho players for the most part possess the ectomorphic and mesomorphic dominant somatotypes. Furthermore, based on the study results, it can be also concluded that somatic attributes in the similar body types also play important role to determine players' performance level. [ABSTRACT FROM AUTHOR]

Relative humidity is a key parameter for the development of delayed ettringite formation (DEF). Here, new results of very-long-term experiments (10 years) are presented. It is observed that for a relative humidity of 96%, swelling could occur after several years but with a slower kinetics. A model coupling the kinetics of swelling with the internal relative humidity is presented. It is shown that this model can reproduce the experimental behavior. [ABSTRACT FROM AUTHOR]

In this paper, in order to provides a powerful new tool for quantitative and qualitative analysis of dynamics properties in flexible mechanical multibody systems, the symmetry theory and numerical algorithms for preserving structure in modern analytical mechanics is introduced into flexible multibody dynamics. First, taking the hub-beam systems as an example, the original nonlinear partial differential-integral equations of the system dynamics model are discretized into the finite-dimensional Lagrange equations by using the assumed modal method. Second, the group analysis theory is introduced and the criterion equations and the corresponding conserved quantities of Noether symmetries are given according to the invariance principle, which provide an effective way for analytic integral theory of dynamic equations. Finally, a conserved quantity-preserving numerical algorithm is constructed by coordinates incremental discrete gradient, which makes full use of the invariance of conserved quantity to eliminate the error consumption for a long time. The simulation results show that the deeper mechanical laws and motion characteristics of flexible mechanical multibody systems dynamics can be obtained with the help of symmetries and conserved quantities, which can provide reference for more precise dynamic optimization design and advanced control of systems. [ABSTRACT FROM AUTHOR]

The study of multibody systems with elastic elements involves at the moment the reevaluation of the classical methods of analysis offered by analytical mechanics. Modeling this system with the finite element method requires obtaining the motion equation for an element in the circumstances imposed by a multibody system. The paper aims to present the main analysis methods used by researchers, to make a comparative analysis, and to show the advantages or disadvantages offered by different methods. For the presentation of the main methods (namely Lagrange's equations, Gibbs–Appell's equations, Maggi's formalism, Kane's equations, and Hamilton's equations) a unified notation is used. The paper provides a critical evaluation of the studied applications that involved some of these methods, highlighting the reason why it was decided to use them. Also, the paper identifies potential research areas to explore. [ABSTRACT FROM AUTHOR]

Analytical mechanics provides methods for analyzing multibody systems with mathematically equivalent elastic elements. The paper analyzes several of these models, highlighting the advantages and disadvantages offered by each of these methods. The main methods used by the researchers are described in a unitary form, presenting the methods of obtaining the evolution equations in each of these cases, mentioning the strengths and weaknesses of each method. The equations of Lagrange, Gibbs–Appell, Kane, Maggi, and Hamilton are analyzed for the particular case of two-dimensional systems, which present certain particularities that facilitate the analysis. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on the kinetics of the binding process of self-hardening moulding sands with an organic binder under conditions of forced air flow at various pressure values. Three moulding sands made using urea-furfuryl resin Furanol FR75A technology were studied. The moulding sands were prepared on a base of quartz sand with an average grain size of dL = 0.25, 0.29 and 0.37 mm, with permeability values of 306, 391 and 476 m²/108Pa · s (for -0 = 1.60, 1.60 and 1.61 g/cm³, respectively). The research was conducted for a resin content of 1% with a constant proportion of hardener to resin, which was equal to 50%. Samples of the tested moulding sands were blown with air at pressures of 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 bar. The kinetics of the hardening process was monitored using ultrasound technology, according to a previously developed methodology [1]. The research was carried out on an ultrasound testing station equipped with a temperature chamber and an airflow reducer. The tests were conducted at a temperature of 20°C, and of the air flow pressure on the changes in ultrasonic wave velocity in the hardening mouldins sand as a function of time, the kinetics of the hardening process, and the degree of moulding sand hardening were determined. Additionally, the influence of the moulding sand permeability on the course of the hardening process at a constant air flow pressure was determined. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is a bottleneck to photoelectrochemical (PEC) water splitting; however, there remains an impressive challenge for intrinsic charge transport for the development of integrated photoanodes. Herein, covalent triazine frameworks as conjugated molecules are grafted on the surfaces of ferroelectric BaTiO3−x (CTF/BTO) nanorod array, and then oxyhydroxide oxygen evolution cocatalyst (OEC) is constructed as an integrated photoanode. The OEC/CTF/BTO array not only achieves a high photocurrent density of 0.83 mA cm−2 at 1.23 V versus reversible hydrogen electrode (vs RHE) and low onset potential of ≈0.23 VRHE, but also optimizes outstanding stability. To disclose the origin, the enhanced PEC activity can be contributed to the integration of CTF and OEC, enhancing light‐harvesting capability, boosting charge carrier mediation, and promoting water oxidation kinetics through electrochemical analysis and density functional theory calculations. This study not only provides an alternative to accelerate charge transfer, but also paves the rational design and fabrication of integrated photoanodes for boosting PEC water splitting performance. [ABSTRACT FROM AUTHOR]

Given the unique characteristic of integrating CO2 conversion and renewable energy storage, metal–CO2 batteries (MCBs) are expected to become the next‐generation technology to address both environmental and energy crises. As involving complex gas–liquid–solid three‐phase interfacial reactions, cathodes of MCBs can significantly affect the overall battery operation, thus attracting much research attention. Compared to conventional materials, 2D materials offer great opportunities for the design and preparation of high‐performance catalyst cathodes, especially showing superior bifunctional electrocatalytic capacity for rechargeable MCBs. The inherent high‐specific‐surface area and diverse structural architectures of 2D materials enable their flexible and rational engineering designs toward kinetically favorable metal–CO2 electrochemistry. Herein this review, the cutting‐edge progresses of 2D materials‐based catalyst cathodes are presented in MCBs. The reaction mechanisms of various MCBs, including both nonaqueous and aqueous systems, are systematically introduced. Then, the design criteria of catalyst cathodes, and the merits and demerits of 2D materials‐based catalyst cathodes are discussed. After that, three representative engineering strategies (i.e., defect control, phase engineering, and heterostructure design) of 2D materials for high‐performance MCBs are systematically described. Finally, the current research advances are briefly summarized and the confronting challenges and opportunities for future development of advanced MCB cathodes are proposed. [ABSTRACT FROM AUTHOR]

The time-sequenced damage behavior of the reactive projectile impacting double-layer plates is discussed. The analytical model considering the combined effect of kinetic and chemical energy is developed to reveal the damage mechanism. The influences of impact velocity and reactive projectile chemical characteristics on the damage effect are decoupled analyzed based on this model. These analyses indicate that the high energy releasing efficiency and fast reaction propagation velocity of the reactive projectile are conducive to enhancing the damage effect. The experiments with various reactive projectiles impact velocity increasing from 702 to 1385 m/s were conducted to verify this model. The experimental results presented that, the damage hole radius of the rear-plate increases with the increase of impact velocity. At the impact velocity of 1350 m/s, the radius of damage hole formed by PTFE/Al/Bi2O3, PTFE/Al/MoO3, PTFE/Al/Fe2O3 projectile on the rear-plate become smaller in sequence. These results are consistent with the analytical model prediction, demonstrating that this model can predict the damage effect quantitatively. This work is of constructive significance to the application of reactive projectiles. [ABSTRACT FROM AUTHOR]

The processing of Shea (Vitellaria paradoxa) pulp juice plays a crucial role in its nutritional and sensory attributes, as well as its bacterial composition. This study aims to investigate the antinutritional factors, sensory properties, and microbial activity in processed Shea pulp juice. The study utilized various analytical methods, including proximate analysis, sensory evaluation, and microbial analysis. The findings provide valuable insights into the nutritional quality, taste profile, and microbial composition of Shea pulp juice after processing. The nutritional analysis revealed a substantial amount of moisture of 84.39 to 93.01%, as well as high carbohydrate and caloric values of 5.84 to 8.96% and 33.51 to 67.31%, respectively. It also had a high vitamin C concentration (16.45 - 38.99%). The anti-nutritional analysis shows the presence of phytate (42.80±1.42mg), and oxalate (0.42±0.22mg), it was also found to be very high in tannin (338.80± 1.36mg). Saponin has a low content of 16.59±0.14mg and Cyanide had the lowest quantity (13.23±0.13). Cyanide, oxalate, and phytate concentrations were found to be lower than the reference toxic standard level. In terms of sensory evaluation, all samples were accepted favorably with Sample A and B most preferable to C. This research contributes to the understanding of Shea pulp juice as a potential food source and highlights the importance of optimizing processing techniques to enhance its beneficial properties. [ABSTRACT FROM AUTHOR]

The main aim of this study was to evaluate the impact of mechanical drying on the sensory quality of specialty coffee produced on three Colombian coffee farms. The technique involved a study of the coffee bean drying process parameters, such as temperature (35, 45 and 55°C), airflow (100 m³/min·m²) and thickness (0.2 m) for mechanical drying, vs conventional drying in the open sun until 11% of moisture content was reached. For mechanical drying, the effective diffusion coefficient, electrical conductivity and drying kinetics were evaluated. A sensory test was performed for three storage periods (3, 6 and 9 months) using the Specialty Coffee Association (SCA) protocol. The results showed that the effective diffusion coefficient varied from 3.21 to 8.02 × 10-7 m²/s for mechanical drying and from 4.21 × 10-11 m²/s for drying in the open sun. The time drying time was established at 20.35 ± 0.06, 29.10 ± 0.09 and 71.52 ± 0.11 hours for mechanical drying at 55°C, 45°C and 35°C respectively and 54.48 ± 11.37 hours for drying in the open sun system. The average moisture content at the end of all drying operations was 12.5%. Electrical conductivity rose from 11.71 to 16.86 µS/cm·g at drying temperatures ranging from 35 to 55°C. The sensory test revealed that storage duration had no effect on the quality of the coffee drink when in touch with the drying process, with mechanical drying yielding higher sensory ratings. The coffee beans were dried at 55°C, yielding coffee samples with SCA scores more than 85 points. In overall, it is determined that the convective mechanical drying method is a viable approach for the processing of specialty coffee beans since it allows for the retention of high-quality sensory qualities, allowing it to command higher market pricing. [ABSTRACT FROM AUTHOR]

This paper proposes a theory that bridges classical analytical mechanics and nonequilibrium thermodynamics. Its intent is to derive the evolution equations of a system from a stationarity principle for a suitably augmented Lagrangian action. This aim is attained for homogeneous systems, described by a finite number of state variables depending on time only. In particular, it is shown that away from equilibrium free energy and entropy are independent constitutive functions. [ABSTRACT FROM AUTHOR]

Herein, we report the fabrication of Ag metal loading on Zr-doped-N-TiO2 (AgZrT) nanocomposites (NCs) via microwave-assisted impregnation reduction method. The main objective of the work is to study the effect of Ag loading on structural, chemical and photoactivity of Zr-doped-N-TiO2(ZrT). The obtained NCs were characterized using XRD, HRTEM, EDS, XPS etc. Obtained AgZrT NCs showed the existence of metastable anatase phase with an average crystallite size of about 10 nm supported by HRTEM. The presence of Ti, Zr and Ag is confirmed by EDS while the metallic state of Ag and oxidation state of Ti and Zr (+4) is confirmed by using XPS. The Ag loading effect on photoactivity of ZrT NPs was studied under UV and direct sunlight using model dye Methyl Orange (MO). The positive impact of Ag metal loading is supported by the enhanced photoactivity of ZrT. The degradation kinetics for MO and its plausible mechanism under sunlight is proposed. [ABSTRACT FROM AUTHOR]

The current study investigates the stability structure of the base periodic motion of an inverted pendulum (IP). A uniform magnetic field affects the motion in the direction of the plane configuration. Furthermore, a non-conservative force as one that dampens air is considered. Its underlying equation of motion is derived from traditional analytical mechanics. The mathematical analysis is made simpler by substituting the Taylor theory in order to expand the restoring forces. The modified Homotopy perturbation method (HPM) is employed to achieve a roughly adequate regular result. To support the prior result, a numerical method based on the fourth-order Runge-Kutta method (RK4) is employed. The graphs for both the analytic and numerical solutions are highly consistent with one another, which indicates that the perturbation strategy is accurate. The solution time history curve exhibits a decaying performance and indicates that it is steady and without chaos. The resonance and non-resonance cases are found through the stability study by using the time scale method. In all perturbation approaches, the methodology of multiple time scales is actually regarded as a further standard approach. The time history is used to create a collection of graphs. Some graphical representations are used to illustrate how the typical physical values affect the behavior of the discovered solution. It has been discovered that the statically unstable IP can have its instability reduced by raising the spring torsional constant stiffness as well as the damped coefficient. Moreover, the magnetic field has a significant role in the stability configuration, which explains that at higher values of this field, the decaying waves take much more time than the smaller values of this field. Accordingly, it can be employed in various engineering devices that need a certain period of time to be more stable. [ABSTRACT FROM AUTHOR]

Crystalline hematite nanoparticles as adsorbents for anionic Congo red dye were prepared by a hydrothermal process using urea hydrolysis. To examine the effects of coexisting anions in a solution on the formation of hematite nanoparticles, different iron(III) salts, including iron chloride hexahydrate, iron nitrate nonahydrate, iron sulfate n-hydrate, ammonium iron sulfate dodecahydrate, and basic ferric acetate, were employed as iron-ion sources. After the hydrothermal treatment of the solution, consisting of an iron salt and urea at 423 K for 20 h, a single phase of hematite was formed from the iron-nitrate solution. The results suggested that the hydrothermal formation of hematite depended on the stability of iron complexes formed in the starting solution. The average crystallite size and median diameter of hematite nanoparticles also depended on the coexisting anions, suggesting that the appropriate selection of the coexisting anions in the starting solution can allow for control of the crystallite size and particle diameter of hematite nanoparticles. The Congo red adsorption kinetics and isotherms of the hematite nanoparticles were described by the Elovich model and Langmuir model, respectively. The adsorption thermodynamics parameters were estimated, which suggested an exothermic and spontaneous process. The results demonstrated good adsorption properties for Congo red adsorption. [ABSTRACT FROM AUTHOR]

With the surge of electric vehicles, fast charging has become one of the major challenges for the development of Li-ion and Li metal batteries. The degradation of battery electrodes at fast charging has been identified as among the gating factors. While there have been extensive studies on anode and cathode degradation modes, not sufficient efforts have been made to dive deep into the kinetics of battery charging and its influence on electrode degradation, especially during fast charging. This review presents a comprehensive yet concentrated perspective into such issues. By tracing back to the kinetic origins of battery charging, it is revealed that the intrinsic properties of electrode active materials and the microstructures of electrode are of great importance in determining electrode kinetics. Most of the electrode degradation modes are closely related to the high overpotentials and the spatial inhomogeneity in Li concentration and pertinent characteristics, which are results of the sluggish electrode kinetics during fast charging. Approaches to mitigate electrode degradation are summarized from the aspect of improving electrode kinetics and circumventing detrimental side reactions. [ABSTRACT FROM AUTHOR]

The inverted pendulum is controlled in this article by using the nonlinear control theory. From classical analytical mechanics, its substructure equation of motion is derived. Because of the inclusion of the restoring forces, the Taylor expansion is employed to facilitate the analysis. An estimated satisfactory periodic solution is obtained with the aid of the modified Homotopy perturbation method. A numerical technique based on the fourth-order Runge–Kutta method is employed to justify the previous solution. On the other hand, a positive position feedback control is developed to dampen the vibrations of an IP system subjected to multi-excitation forces. The multiple time scale perturbation technique of the second order is introduced as a mathematical method to solve a two-degree-of-freedom system that simulates the IP with the PPF at primary and 1:1 internal resonance. The stability of these solutions is checked with the aid of the Routh–Hurwitz criterion. A set of graphs, based on the frequency response equations resulting from the MSPT method, is incorporated. Additionally, a numerical simulation is set up with RK-4 to confirm the overall controlled performance of the studied model. The quality of the solution is confirmed by the match between the approximate solution and the numerical simulation. Numerous other nonlinear systems can be controlled using the provided control method. Illustrations are offered that pertain to implications in design and pedagogy. The linearized stability of IP near the fixed points as well as the phase portraits is depicted for the autonomous and non-autonomous cases. Because of the static stability of the IP, it is found that its instability can be suppressed by the increase of both the generalized force as well as the torsional constant stiffness of the spring. Additionally, the presence of the magnetic field enhances the stability of IP. [ABSTRACT FROM AUTHOR]

For the system with non-holonomic constraints, the principle of least action does not seem to lead to the equations describing the motion, which are consistent with the physical behaviour. Here, some considerations are developed on this fundamental topic in Mathematical Physics. Moreover, a thermodynamic approach is introduced based on the first and second laws of thermodynamics.

Iconography and symbolism of religion, correspondingly, are vital and convoluted aesthetic patterns and kinetics in a well-used foundational manner to transcend religious theories and the optical, audible and gesture depictions of religious intelligence with narratives. Iconography and symbolism of religion gain autonomy from all world religions. Subsequently, during the 20th centennial, a few academics emphasized the significance of religious spirit to persuade in citing religion as a rational entity. The symbolic condition of religion is alike viewed by a few academics of mythos and psyche as essential idiosyncratic with a religious explanation. Academics from provisional religionists, developmentalists and psychiatrists harvested with explanation the vast plethora of data on the emphasised views within religion, notably within association with East as well as Western religions. In the new liturgical theology of Christian formalities, additional appraisal of religiously emphasised syntax has transpired. Contribution: In this article, kinetics of symbols and visuals that are presented in a specific pattern and tenacious accord to the structure, subject matter and motives of the proposal are proclaimed to be among the most profound ways of experiencing and articulating religious details. Such patterns, as I think Prof. Johan Buitendag would agree, also add to the care and reinforced accords between sapiens3 with its domain that is revered or divine transcendental, metaphysical magnitude. That is what this article is about! [ABSTRACT FROM AUTHOR]

Kinetic parameters correlation is fundamental in biodiesel production, operation, and design. In this work, a MATLAB® application was developed to correlate kinetic parameters in the biodiesel production from palm kernel oil. The functions fminsearch, fmincon, and genetic algorithm were employed to correlate energies, frequency factors, and reaction order. The tool was validated with experimental results reported in the literature. The correlated parameters with the genetic algorithm function show the most accurate result, it did not require initial estimation for the correlation process, and the convergence process did not stop a wrong local optimum, without losing the fundamental objective of this article, which is to facilitate the correlation of kinetic parameters. [ABSTRACT FROM AUTHOR]

Temperature control is probably the most important factor that influences a chemical reaction yield, in particular when working with strongly exothermic reactions. The oxidation of 2-octanol to 2-octanone is a well-known two phase (liquid-liquid) oxidation reaction, and it suffers of yield loss due to side reactions that lead to further oxidation to a mixture of carboxylic acids. As the reaction is exothermic, controlling the reactor temperature is extremely important for a safe operation. A temperature control naturally induces fluctuations within the system, which can impact the kinetics of the desired reaction. The aim of this work is to investigate the impact of the Proportional-Integral temperature controller parameters on the conversion to 2-octanone. The reaction is carried out in a semi-batch reactor, dosing 2-octanol on a solution of nitric acid. The production of nitrosonium ion is promoted by adding sodium nitrite to the nitric acid. The reaction is carried out with high stirring speed, in order to work under full chemical control regime, avoiding the effect of material diffusion between the two phases. Several simulations were done referring to an Easymax™ 402 Workstation (Mettler Toledo) under an isothermal temperature control mode. Target temperatures were chosen in the -15 - 15 °C range. The proportional parameter was tested in the range of 5-15, and the integral parameter was kept in the range of 60-600 s. Results showed that runaway boundaries are significatively affected by the values of the temperature controller parameters, highlighting how it is fundamental a calorimetric investigation of the process in view of a safe process optimization. [ABSTRACT FROM AUTHOR]

In the context of process intensification, milli-structured plate reactors provide significant advantages over conventional reactors in terms of heat and mass transfer as well as process safety. The ART® plate reactor PR37 of Ehrfeld Mikrotechnik GmbH offers excellent heat transfer, narrow residence time distributions and high mixing efficiency, while simultaneously allowing an effective scale-up to industrial applications due to its modular set up. This does not only enable the realization of novel process windows exceeding the limits of conventional reactors, but also provides optimal prerequisites for kinetic modelling due to the well-defined process conditions, providing key information regarding process design and optimization. The integration of the ART PR37 with Model-based Design of Experiments (MBDoE) allows for an intensification of kinetic studies, combining the well-defined operating conditions with a rapid and targeted identification of kinetic models. In the current study this combination is applied to successfully identify the kinetics of a multistep aromatic nucleophilic substitution reaction with low experimental effort, saving time and resources compared to conventional factorial Design of Experiments. [ABSTRACT FROM AUTHOR]