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This paper presents the results of experimental tests and computer simulations on the stiffness of composite aluminium mullions used in unitised façades. The elements analysed were subjected to bending in order to simulate the actual operating conditions of aluminium façades subjected to significant wind pressure or suction loads. The basic mechanical and physical properties of the materials from which the analysed type of aluminium façade is made (Aluminium EN AW-6060 in the T66 temper and polyamide PA66 25GF), the test method, and the results obtained are described. As a result of the tests, equivalent moments of inertia of the composite profile (aluminium profile with the thermal break) were determined, which are strongly dependent on the strength of the connection between the individual elements, the asymmetry of the cross-section, and the properties of the thermal break. Strain measurements carried out using FBG (Fiber Bragg Grating) strain sensors installed in the profiles under tests allowed for determining the actual stress values of the aluminium profiles under consideration. The results obtained were compared to theoretical (numerical) values, indicating discrepancies at higher load values. The methodology presented in this article is to be used to monitor the deformation of the aluminium façade mullions of HRB (High-Rise Buildings). [ABSTRACT FROM AUTHOR]

The interpretation and visualization of engineering problems are complex. Therefore, engineers have always developed graphic procedures to solve these problems, one technique being Mohr's circle. The study of geometric properties of the cross-sections, plane stress, and plane strain are some applications of such techniques in Solid Mechanics. In practically all literature adopted in undergraduate courses on these topics, the efforts of authors to teach with the greatest clarity are remarkable, using all possible resources in books, with very well-designed graphics. However, concerning Mohr's circle, the mental visualization of some movement is needed, be it the rotation of points on the circle, the rotation of the cross-section, the axes, or the differential element. This need makes such topics ideal to be taught through interactive animations, impossible in books. Computer programs about these subjects do exist, however, with reduced user interactivity. Thus, this work presents a new unified mobile application with several useful interactivity features for teaching plane stress, plane strain, and moment of inertia in engineering courses, using Mohr's circle. The application is developed in Java programming language, using Android Studio software. The graphical environment was developed with the aim of being a didactic and intuitive way to study and learn about cross-section properties, plane stress, and plane strain. The results provided by the application are compared with examples from the literature, presenting accurate responses, with easy visualization and interpretation. The usage of the program makes studying the initial concepts of solid mechanics and Mohr's circle enjoyable for engineering students. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the dynamics of charged compact stars in f (R) theory of gravity, where f is a function of the Ricci scalar R . For this purpose, we investigate the field equations in the presence of charge using f (R) modified gravity. Moreover, we manipulate the field equations to get a single non-linear differential equation due to complicated nature of equations and employ some numerical techniques to get the desired solutions. We also investigate some physical properties of compact stars including energy density, pressure component, equation of state parameter, energy conditions, and causality conditions respectively. Furthermore, we examine the dynamics of slowly rotating compact stars by using f (R) = R + α R 2 gravity model. For our current analysis, we have chosen six compact stars namely P S R 1903 + 327 , P S R 1937 + 21 , P S R J 1614 - 2230 , C e n X - 3 , V e l a X - 1 and 4 U 1608 - 52 . Employing a first-order approximation in angular velocity, we calculate the mass-radius relationship and moment of inertia for these considered compact stars. Additionally, we investigate the relationships between mass and energy density with respect to the radius of the compact star, which exhibits the natural behavior, thereby validating our approach. [ABSTRACT FROM AUTHOR]

Based on the PREM Earth model, more than a thousand models of the internal structure of Venus have been built, differing in the radius and density of the core, the density of the mantle, the viscosity distribution and rheology. The core radius varies from 2800 to 3600 km, and the density in the mantle and core varies within a few percent of the PREM model values. When calculating tidal Love numbers, Andrade rheology is used to take into account the inelasticity of the mantle. Specifically the values of the Andrade rheological model parameters that best describe the tidal deformation of the Earth are used. This significantly reduces the error when calculating Love numbers. It has been shown that Venus can have an internal solid core only if the composition of the planet is very different from that of Earth. Comparison of the observed values of the moment of inertia and tidal Love number k2 with model values allowed us to conclude that the radius of the core of Venus is with a high probability in the range of 3288 ± 167 km. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Robot is an indispensable technology within the context of the Industrial 4.0 revolution, providing a wide range of applications in industry. The stability of a robot's manipulator is contingent upon its associated manipulator settings, hence influencing its overall quality. The assessment of stability has been examined in prior studies using a limited set of manipulator parameters, leading to a deficient comprehension of this phenomenon. In this study, a mathematical model of a flexible six-link manipulator is formulated using Lagrangian mechanics and various parameters. An innovative mathematical framework is developed to establish a correlation between stability and the motor acceleration and moment of inertia for the Universal Robot (UR5). Furthermore, extensive research has been conducted to examine the correlation between stiffness, damping, and deflection in the context of stability. In spite of this, fuzzy logic inference methods are employed to ascertain the relative significance of stiffness, damping, and deflection with regards to stability. Mathematical approaches are employed to validate the numerical values of several manipulator parameters. The findings of the study demonstrate that there is a positive correlation between motor acceleration and stability, indicating that as motor acceleration grows, stability also increases. Conversely, there is a negative correlation between stability and moment of inertia, suggesting that stability reduces as moment of inertia increases. In the case of stiffness, damping, and deflection, stiffness is the most important factor. When stiffness is high, stability is also high. However, when stiffness is minimal, stability is low. The implications of these findings are expected to have a positive impact on enhancing industrial productivity.

The carbon fiber triaxial woven fabric has good application prospects in the field of space deployment devices because of its advantages of stable structure， light density and quasi-isotropic. In order to study the deformation properties of carbon fiber triaxial woven fabric/thermoplastic polyurethanes （TPU） flexible composite， TPU and carbon fibertriaxial woven fabric were composited by hot pressing. The unit cell model of triaxial woven fabric was established by metallographic microscope and SEM.The moment of inertia of different sections was calculated by the model， the moment of inertia of the weft section is greater than that of the warp， and the triaxial woven fabric is more difficult to deform in the weft direction. Drape experiments were performed on carbon fiber plain fabric and triaxial woven fabric.The results show that the deformation ability of the triaxial woven fabric is stronger than plain fabric， and the warp direction deformation of triaxial woven fabric is greater than the weft when it is draped， which is consistent with the calculation result of the moment of inertia of the model section； triaxial woven fabric is subjected to tensile tests in the 0°，15°and 30°directions， the load curve changes and ultimate loads of the three angles are analyzed at different strain stages.

Correctly measuring of the moments of inertia of fragments of binary fission of actinide nuclei helps solve the important problem in nuclear physics of determining the spins of such fragments. The moments of inertia are calculated using the solid rotation, hydrodynamic, and superfluid models. The best agreement with experimental data is obtained using the superfluid model with an oscillatory potential. [ABSTRACT FROM AUTHOR]

Teaching damped simple harmonic motion (shm) is a pedagogical challenge that requires additional strategies for the teaching and learning process of the associated physical concepts and mathematical structures, thus representing a greater effort in a non-face-to-face mode. A pedagogical guide for remote work was implemented, based on the homemade torsion pendulum model, supported by computational, digital, and ict tools for the study of damped shm. The experiment was conducted with three cohorts of second-year Physics students. It was demonstrated that the torsion pendulum is a valid model for learning concepts associated with damped harmonic motion and for developing competencies in experimental work. [ABSTRACT FROM AUTHOR]

Geographic shape has long been an intriguing feature of observed and defined facets of an area or region. Compactness reflects a critical element of shape with important practical and policy implications. It may suggest characteristics of urban/regional form, efficiency in trade and service provision, fairness in political representation and distributional qualities of the physical environment, among others. While there has been much study of compactness and a wealth of measures and metrics derived to reflect nuances of geographic form, there are questions that remain about their ability to characterize shape in a meaningful manner. Given this, exploration of relationships between various categories of methods for quantifying compactness is critical. Further, recent developments of, advances in and access to physics based spatial measures of compactness suggest an opportunity for better theoretical understanding. Assessment of 388 districts is carried out. Significant correlation is demonstrated between contemporary measures, opening the door for research advancements associated with the compactness of spatial shapes. This work is interesting, important, and of current relevance because compactness measures are given serious consideration in management, planning, and policy, but also are regularly relied upon in legal proceedings. Further, compactness measures continue to drive automated and semi‐automated approaches in districting and redistricting, often embedded in optimization approaches. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper presents the modification of the first 6 natural frequencies for a PCB case where the material quality was modified from Ultradur B4300 G6 material in AlSi12Cu1 aluminum alloy. Following the change in the quality of the materials, the natural frequency of the 1st vibration mode changed from 164 Hz to 378 Hz, as a consequence of the change in the modulus of elasticity, respectively the stiffness.

The utilization of lattice-type cellular architectures has seen a significant increase, owing to their predictable shape and the ability to fabricate templated porous materials through low-cost 3D-printing methods. Frames based on atomic lattice structures such as face-centered cubic (FCC), body-centered cubic (BCC), or simple cubic (SC) have been utilized. In FDM, the mechanical performance has been impeded by stress concentration at the nodes and melt-solidification interfaces arising from layer-by-layer deposition. Adding plates to the frames has resulted in improvements with a concurrent increase in weight and hot-pocket-induced dimensional impact in the closed cells formed. In this paper, we explore compressive performance from the partial addition of plates to the frames of a SC-BCC lattice. Compression testing of both single unit cells and 4 × 4 × 4 lattices in all three axial directions is conducted to examine stress transfer to the nearest neighbor and assess scale-up stress transfer. Our findings reveal that hybrid lattice structure unit cells exhibit significantly improved modulus in the range of 125% to 393%, specific modulus in the range of 13% to 120%, and energy absorption in the range of 17% to 395% over the open lattice. The scaled-up lattice modulus increased by 8% to 400%, specific modulus by 2% to 107%, and energy absorption by 37% to 553% over the lattice frame. Parameters that emerged as key to improved lightweighting. [ABSTRACT FROM AUTHOR]

Tests of a streamlined cone with a rear hemispherical part were carried out in a supersonic wind tunnel using an installation of free oscillations along the pitch angle at Mach number M = 1.75 and for several values of the body inertia moment (calculated relative to the axis of rotation). In all tests, after the completion of the transient process, undamped oscillations of the cone were recorded with an amplitude depending on the reduced frequency. The dependence for the of undamped oscillation amplitude on the reduced frequency exhibits a pronounced resonant behavior. [ABSTRACT FROM AUTHOR]

Neutron stars (NSs) are compact objects that host the densest forms of matter in the observable universe, providing unique opportunities to study the behaviour of matter at extreme densities. While precision measurements of NS masses through pulsar timing have imposed effective constraints on the equation of state (EoS) of dense matter, accurately determining the radius or moment of inertia (MoI) of an NS remains a major challenge. This article presents a detailed review on measuring the Lense–Thirring (LT) precession effect in the orbit of binary pulsars, which would give access to the MoI of NSs and offer further constraints on the EoS. We discuss the suitability of certain classes of binary pulsars for measuring the LT precession from the perspective of binary star evolution and highlight five pulsars that exhibit properties promising to realise these goals in the near future. Finally, discoveries of compact binaries with shorter orbital periods hold the potential to greatly enhance measurements of the MoI of NSs. The MoI measurements of binary pulsars are pivotal to advancing our understanding of matter at supranuclear densities, as well as improving the precision of gravity tests, such as the orbital decay due to gravitational wave emission, and of tests of alternative gravity theories. [ABSTRACT FROM AUTHOR]

Predicting the initial crack load in concrete is important to detect early warning of a problem. In this study, a model for predicting the first crack load on a hollow-cored rectangular beam point loaded at mid-span was developed by combining a numerical method and an experimental approach. The modulus of rupture was introduced into the governing moment-curvature relationship. Experimentally, flexural testing with point loads at mid-span was performed on fifteen (15) beams made up of three (3) beam types at 1 kN intervals for a span of 750mm using the Universal Testing machine. The beams were simply supported by roller points. The dimensions of the beams were kept constant and later varied while investigating the following hollow diameters: 0, 30, 60, 75, and 105mm. Numerically, the beams were designed as a beam element point loaded at mid-span with a span of 700mm centers, and the support conditions were defined as pinned support. Governing equations relating failure load with the modulus of rupture, stiffness matrix, shape functions, and moment of inertia were developed. The equation for predicting the first crack load, incorporating the modulus of rupture, was derived. The moment of inertia was calculated by discretizing the hollow-cored beam section using an isoparametric geometric transformation. The experimental results were used to validate the numerical model. 90.55% agreement between experimental and numerical results was observed. The overall average percentage difference between the two methods recorded is 9.45%. This shows that at about 91% confidence level, both approaches are the same and can be applied with confidence in the prediction of the first crack load on hollow-cored reinforced concrete beams. [ABSTRACT FROM AUTHOR]

The authors developed a vibration suppression device (VSD) that has variable moment of inertia using magneto-rheological (MR) fluid in order to get series inertia mass effect for vibration reduction. In previous paper, the proto-type VSD was manufactured and the variable series inertia mass effect was confirmed. From the experimental results, the series inertia mass effect can be switched by the current of electromagnets. And theoretical model of solidified form of the fluid was proposed by formula and the trend were closed the experimental results. Then the vibration tests of 1DOF system with the VSD were conducted by a shaking table. Vibration reduction of the VSD was confirmed. The current of the electromagnet was controlled by using the reinforcement learning. But the fluid behavior inside the flywheel has not investigated before. In this paper, to investigate the fluid behavior inside the flywheel, it is analyzed by computational fluid dynamics (CFD). Three types of the flywheels are manufactured, and 2 types of electromagnets are used here. Equivalent inertia mass in totally 20 cases of the flywheel and the electromagnets are numerically calculated by using the OpenFOAM, and also measured in experiments. From the analytical results, convection is initially occurred in the direction of the magnetic poles when the magnetic field applies, and then the particles are eventually solidified at locations other than near the magnetic poles. Finally, the analytical results are compared with the theoretical and the experimental results.

ABSTRACT There is a lack of knowledge in the literature concerning Body Segment Inertial Parameters (BSIP) for children aged 4 to 15 years. Nevertheless, these data are fundamental for studying the dynamics of the healthy and pathological musculoskeletal system. One common method for obtaining BSIP is to use regression equations derived from anthropometric tables. However, the majority of these equations are based on adult data. In this study, we compared certain BSIP (segment mass, center of mass position, and transverse moment of inertia) derived from adult anthropometric tables with the corresponding BSIP extracted from a pediatric anthropometric table. The goal of this study was to determine the accuracy of using adult anthropometric tables to calculate pediatric BSIP. For this comparison, we assessed the proximity of several adult anthropometric tables to a pediatric anthropometric table by Jensen (1986) for each BSIP. Our results revealed differences between the BSIP obtained using adult tables and the BSIP obtained with the pediatric table used as a reference. When considering all the tables, the mean relative difference was 12% for segment mass, 12% for center of mass position, and 25% for transverse moment of inertia. Notably, the greatest relative differences were observed for the head, hand, and foot segments. Additionally, the relative difference in female data was higher compared to males. This result could be attributed to the predominant use of male subjects in the adult tables considered in this study. Finally, the adult anthropometric tables by Dumas and Wojtsuch (2018) and De Leva (1996) provided results that were closer in comparison to Jensen (1986).

The dynamic performance of a high-speed train is heavily influenced by its centre of gravity and moment of inertia. Therefore, accurately measuring these parameters is crucial. This paper proposes an integrated test method for measuring the centre of gravity and moment of inertia based on the excitation method by analyzing the structural characteristics of the vibration test bench. The proposed method is efficient as it only requires installing the car body once, unlike the past method of combining excitation and suspension. This paper provides a comprehensive theoretical derivation of the method used to test the center of gravity and moment of inertia of a specific type of high-speed electrical motor units (EMU) car body. The results of the test were compared to the theoretical values, and the error was found to be minimal, meeting the necessary engineering application requirements. [ABSTRACT FROM AUTHOR]

The paper presents the modification of the first 6 natural frequencies for a PCB case where the material quality was modified from Ultradur B4300 G6 material in AlSi12Cu1 aluminum alloy. Following the change in the quality of the materials, the natural frequency of the 1st vibration mode changed from 164 Hz to 378 Hz, as a consequence of the change in the modulus of elasticity, respectively the stiffness. [ABSTRACT FROM AUTHOR]

The effect of interaction between hyperons on the moment of inertia of proto neutron star (PNS) PSR J0740+6620 is examined with relativistic mean field theory considering the octet of baryons. The nucleon coupling constant GM1 is used and the temperature of the PNS is chosen as T = 20 MeV. Under the constraint of the mass M = 2.08 M ⊙ , considering the interaction between hyperons, the radius of the PNS PSR J0740+6620 is reduced by 0.08% from R = 14.518 km to R = 14.507 km and the moment of inertia of the PNS PSR J0740+6620 is reduced by about 0.49% from I = 2.460 × 10 45 g cm 2 to I = 2.448 × 10 45 g cm 2 , respectively. The moment of inertia of the PNS has a peak with the change of central energy density ε c , mass M or radius R. Considering the interaction between hyperons, the value of the moment of inertia I of the PNS corresponding to this peak will decrease. [ABSTRACT FROM AUTHOR]

We investigate how the moment of inertia of the atomic nucleus can be calculated in terms of the invariant operator of its SU(3) symmetry. This question is important for model Hamiltonians containing the moment of inertia explicitly, e.g., those with multichannel dynamical symmetry, which describes many different bands in a unified way. [ABSTRACT FROM AUTHOR]

There is a lack of knowledge in the literature concerning Body Segment Inertial Parameters (BSIP) for children aged 4 to 15 years. Nevertheless, these data are fundamental for studying the dynamics of the healthy and pathological musculoskeletal system. One common method for obtaining BSIP is to use regression equations derived from anthropometric tables. However, the majority of these equations are based on adult data. In this study, we compared certain BSIP (segment mass, center of mass position, and transverse moment of inertia) derived from adult anthropometric tables with the corresponding BSIP extracted from a pediatric anthropometric table. The goal of this study was to determine the accuracy of using adult anthropometric tables to calculate pediatric BSIP. For this comparison, we assessed the proximity of several adult anthropometric tables to a pediatric anthropometric table by Jensen (1986) for each BSIP. Our results revealed differences between the BSIP obtained using adult tables and the BSIP obtained with the pediatric table used as a reference. When considering all the tables, the mean relative difference was 12% for segment mass, 12% for center of mass position, and 25% for transverse moment of inertia. Notably, the greatest relative differences were observed for the head, hand, and foot segments. Additionally, the relative difference in female data was higher compared to males. This result could be attributed to the predominant use of male subjects in the adult tables considered in this study. Finally, the adult anthropometric tables by Dumas and Wojtsuch (2018) and De Leva (1996) provided results that were closer in comparison to Jensen (1986). [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the kinetics of the front arm in cricket fast bowling. Eighteen male fast bowlers (mean age = 17.2 ± 1.6 years; mean height = 1.89 ± 0.05 m; mean mass = 85.0 ± 10.0 kg) were recruited from NSW grade club level and their bowling actions recorded by a Cortex 2.0 motion analysis system (200 Hz). The interaction between joint power and joint angular velocity data was observed simultaneously for the front shoulder and elbow joints. A joint actuation strategy (active or controlled) was assigned to shoulder flexion–extension, abduction–adduction, and elbow flexion–extension motion to understand whether the joint kinematics followed the time-history of the joint torque. The results only partially agreed with the commonly prescribed coaching maxim of "pulling down" the front arm for faster ball speeds. Active extension and adduction of the front shoulder joint were observed during the delivery phase of the action, whereas the acceleration phase was marked by periods of controlled shoulder extension and active shoulder flexion. At the elbow joint, active elbow flexion was observed at a time when it may reduce the moment of inertia about the thoracic and lumbar spine rotation axes. Overall, combinations of active and controlled joint powers were observed for the front shoulder and elbow joints, implying that this sample of bowlers did not adhere to the traditional notion of "pulling down" the front arm as fast as possible. [ABSTRACT FROM AUTHOR]

This article deals with the issue of fair determination of students' knowledge level and increasing their activity in classes using the method of interactive confused logical chain. Using the method for the topic, section and whole part of theoretical mechanics, it is shown that it is possible to evaluate the level of students' knowledge fairly, transparently and quickly. [ABSTRACT FROM AUTHOR]

Porcine models in injury biomechanics research often involve measuring head or brain kinematics. Translation of data from porcine models to other biomechanical models requires geometric and inertial properties of the pig head and brain, and a translationally relevant anatomical coordinate system (ACS). In this study, the head and brain mass, center of mass (CoM), and mass moments of inertia (MoI) were characterized, and an ACS was proposed for the pre-adolescent domestic pig. Density-calibrated computed tomography scans were obtained for the heads of eleven Large White × Landrace pigs (18–48 kg) and were segmented. An ACS with a porcine-equivalent Frankfort plane was defined using externally palpable landmarks (right/left frontal process of the zygomatic bone and zygomatic process of the frontal bone). The head and brain constituted 7.80 ± 0.79% and 0.33 ± 0.08% of the body mass, respectively. The head and brain CoMs were primarily ventral and caudal to the ACS origin, respectively. The mean head and brain principal MoI (in the ACS with origin at respective CoM) ranged from 61.7 to 109.7 kg cm2, and 0.2 to 0.6 kg cm2, respectively. These data may aid the comparison of head and brain kinematics/kinetics data and the translation between porcine and human injury models. [ABSTRACT FROM AUTHOR]

Robotics is a crucial technology of Industry 4.0 that offers a diverse array of applications in the industrial sector. However, the quality of a robot's manipulator is contingent on its stability, which is a function of the manipulator's parameters. In previous studies, stability has been evaluated based on a small number of manipulator parameters; as a result, there is not much information about the integration/optimal arrangement/combination of manipulator parameters toward stability. Through Lagrangian mechanics and the consideration of multiple parameters, a mathematical model of a modern manipulator is developed in this study. In this mathematical model, motor acceleration, moment of inertia, and deflection are considered in order to assess the level of stability of the ABB Robot manipulator of six degrees of freedom. A novel mathematical approach to stability is developed in which stability is correlated with motor acceleration, moment of inertia, and deflection. In addition to this, fuzzy logic inference principles are employed to determine the status of stability. The numerical data of different manipulator parameters are verified using mathematical approaches. Results indicated that as motor acceleration increases, stability increases, while stability decreases as moment of inertia and deflection increase. It is anticipated that the implementation of these findings will increase industrial output. [ABSTRACT FROM AUTHOR]

As an important mechanical parameters of permanent magnet synchronous motor (PMSM), the moment of inertia determines the control optimization and condition monitoring performance of the controller. However, since inertia cannot be measured directly, it is necessary to choose an appropriate method to identify inertia. In this paper, an extended sliding mode observer (ESMO) is proposed by taking the motor speed and inertia as the extended state variable of the observer to identify the inertia. A deformation mode of a saturation function is used as the switching function to mitigate the chattering phenomenon of conventional SMO. For unknown disturbance torque in the state equation, an improved radial basis function neural network (RBFNN) is proposed to estimate it. The improved RBFNN determine the RBF center through the eigenvector of the input data and then trains the neural network, which improves the training accuracy. The effectiveness of the method is verified by simulation experiments. The experiments show that the ESMO combined with the improved RBFNN can effectively and accurately identify motor inertia which is a method worthy of reference.

Civil multi-story structures are used as office buildings or residential buildings. The central pillars on the ground floor of the civil structures will have the largest gravitational load and implicitly will be the pillars most stressed in compression. In this paper, the authors propose to increase the critical buckling load of the central pillars on the ground floor in the event that it is necessary to strengthen these pillars, due to the change in the purpose of the building and the modification of the loads on the floors. To increase the buckling load in the case of these columns, it is proposed to increase the moment of inertia of the columns on the base region. To highlight how the critical loss of stability load changes, a theoretical model is made for the column with constant section and another for the column with variable section in steps. Finally, the results obtained for the critical load will be compared and it will be highlighted what is the increase in buckling load for the pole with variable section in relation to the pole with constant section.

The properties of superdeformed (SD) bands of isodiaphere nuclei ((_ ^40)Ca,(_ ^58)Cu,(_ ^60)Zn) have been studied in the scope of four and five parameters’ formulas of the Bohr-Mottelson collective model. The unknown parameters are obtained by fitting the experimental measurements of the gamma-ray transition energies using MATLAB software. The rotational frequency ℏω, the kinematic J^((1)), and dynamic J^((2)) moments of inertia are determined by using the best fitted parameters. The obtained 𝛾-ray transition energies 𝐸𝛾 are in good agreement with the experimental measurements. Also, the theoretical results of the kinematic J^((1)), and dynamic J^((2)) moments of inertia using both formulas agree well with the experimental data. The staggering ΔI=2 phenomenon is represented by using various order derivatives of -ray transition energies E_γ with respect to spin angular momentum I. We conclude that the five parameters formula of Bohr-Mottelson collective model successes in interpreting the appeared pairing correlations in the experimental measurements for the studied nuclei.

This study delves into moment of inertia in rigid body mechanics, a crucial concept in physics. While it’s traditionally taught through integration, we propose an alternative method using discrete mass segments. This approach simplifies calculations, particularly for symmetric bodies, without complex integration procedures. Our goal is to enhance students’ understanding of fundamental physics principles, making the subject more accessible. We also provide visual aids and online animations to aid comprehension.

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The interior structure of Phobos has been the subject of debate in recent years, with the moment of inertia being a determining factor. To study this structure, we modeled Phobos with a two-layer structure and calculated its mean density and moment of inertia using updated gravity coefficients of degree-2 and forced libration amplitudes. By minimizing the misfit between modeled and derived moment of inertia, and observed and modeled mean density, we determined the frequency distribution for estimated parameters, including the core radius rc, core density ρc, and density ρm of the outer layer. Our results indicate that the optimized core radius is around 8.2 km for our models, along with a core density compromise of approximately 2500 kg·m−3, and an outer layer density of around 1400 kg·m−3. These values have remarkable sensitivity to the misfit function, implying a higher density likely inside Phobos compared to the outer layer. Given that the large core density was associated with ice content, it suggested that the fractional ice content in the outer layer is approximately 11% with a rock density of 2200 kg·m−3, while the content in the core is lower at 2.4% with a rock density of 3000 kg·m−3. The methodology introduced in this study can be further used to study the interior structure of irregularly shaped asteroids. [ABSTRACT FROM AUTHOR]

This paper discusses the importance of accurately identifying the parameters and states in permanent magnet synchronous motors (PMSMs) and their impact on motor performance and efficiency. This study was conducted to demonstrate the significance of these parameters. The results showed that inaccurate identification of the friction coefficient and moment of inertia led to poor motor performance, instability, and reduced efficiency. Accurate identification of these parameters is necessary for the proper control and operation of PMSMs. This paper highlights the various methods for calculating the friction coefficient and moment of inertia, as well as their potential limitations. The findings of this study emphasize the importance of accurately identifying these parameters for the efficient and effective operation of PMSMs. [ABSTRACT FROM AUTHOR]