Nonlinear Dynamic Modelling of a Suspension Seat for Predicting the Vertical Seat Transmissibility

Suspension seats are widely used in heavy vehicles to reduce vibration transmitted to human body and promote ride comfort. Previous studies have shown that the dynamics of the suspension seat exhibits nonlinear behaviour with changed vibration magnitudes. Despite various linear seat models developed in the past, a nonlinear model of the suspension seat capturing the nonlinear dynamic behaviour of the seat suspension and cushion has not been developed for the prediction of the seat transmissibility. This paper proposes a nonlinear lumped parameter model of the suspension seat to predict the nonlinear dynamic response of the seat. The suspension seat model comprises of a nonlinear suspension submodel integrated with a nonlinear cushion submodel. The parameters of the submodels are determined by minimizing the error between the simulated and the measured transmissibility of the suspension mechanism and the force-deflection curve of the seat cushion, respectively. The model of the complete seat is then validated using the seat transmissibility measured with inert mass under vertical vibration excitation. The results show that the proposed suspension seat model can be used to predict the seat transmissibility with various excitation magnitudes.

“Particle of God” as insulting of the Divine Principle

The author’s research has shown that fundamental magnetic poles (magnetic charges) are real structural components of atoms and substance. It is the magnetic poles, and not the moving electric charges are the direct sources of all magnetic fields and magnetic manifestations in Nature. The main reasons that real magnetic charges were “buried alive” in modern theories are the physics of its confinement in substance which is radically different from the confinement of electrons, as well as the vicious electromagnetic theory (electric magnetism) of Maxwell (1873). The vicious ignoring of real magnetic charges, as well as true anti-electrons in physical science for almost 150 years is responsible for the appearance of such global theoretical delusions as the curvature of 4-dimensional space-time, explaining the nature of gravity, the global expansion of the Universe and the big bang. Annihilation of particles in the pairs particle - antiparticle and many, many others. The author’s experiments have shown that the gravitational field is the vortex electromagnetic field, and all varieties of Physical Mass (FM) are of the electromagnetic atom-figurative structures, which are capable of emitting gravitational field. The masses are, for example, atoms and nucleons. If magnetic charges are removed from the FM composition, then only electric particles will remain in this “place” which themselves, without the participation of magnetic poles, are not able to form either mass or gravitational field. All fundamental electric and magnetic particles are not and cannot become masses, and even “God particles” cannot change anything here. The notion the famous Higgs boson and its main purpose - to give mass to particles is of just a vicious theoretical fiction and a sad result of following erroneous electromagnetic concept of Maxwell. In addition, there is no division of Masses into gravitational and inert ones. The concepts of gravitational and inert mass refer to the same electromagnetic structure, called Mass, but they correspond to different processes of interaction of its gravitational field with other masses (so-called gravitational mass) and the environment (so-called inert mass). As for spinor particles, that is, charged particles, they have the property of inertia, however, this circumstance cannot bind these particles with of a real mass.

DIFFERENTIAL EQUATIONS FOR TRAIN STARTING WITH ELASTIC CONNECTIONS

The starting mode for the train is the most difficult. An effective method of pulling is the selection of coupling clearances. In this case, the cars are set in motion sequentially and the inert mass, as well as the static friction force immediately at the moment of starting, are minimal. This method has two significant drawbacks - a small fixed value of the gaps in the couplings and the shock nature of the impulse transfer. These disadvantages can be avoided by using elastically deformable couplings. The aim of this work is to construct a mathematical model of "easy" starting of a train with elastic couplings. The softening of the train start-off mode is essentially due to the replacement of the simultaneous start-off of the sections with alternate ones. To exclude longitudinal vibrations of the composition, after reaching the maximum tension of the coupling, the possibility of its harmonic compression should be mechanically blocked.

Differential equations of the start of motion of elasticly coupled inert bodies on the example of a train with elastic couplings

The starting mode for a ground vehicle is the most difficult. An effective way to pull off a train is to select coupling clearances. In this case, the cars are set in motion consequently, and the inert mass, as well as the static friction force immediately at the moment of starting, are minimal. This method, however, has two significant drawbacks – a small fixed value of the gaps in the couplings, which limits the effectiveness of the method and the shock nature of the impulse transmission, which negatively affects the state of the structural elements of the train. These disadvantages can be avoided by using elastically deformable couplings. The aim of this work is to construct a mathematical model of "easy" starting of a train with elastic couplings. The softening of the starting mode of the train is essentially due to the replacement of the simultaneous starting of the sections with alternate ones.

Approaches to Predicting the Vertical Transmissibility of a Suspension Seat With a Seated Subject

In this paper, four methods were put forward to predict the transmissibility of an air suspension seat with a seated subject. For characterizing the dynamics of the suspension seat, two of the methods were based on developing a model of the air suspension seat and calibrating the parameters using the transmissibilities of the suspension and complete seat respectively with an inert mass from the experiment. The other two methods substituted the detailed modeling of the seat by two dynamic stiffness connecting in series calculated from two same transmissibilities measured in the experiment. For characterizing the biodynamics of the human body, two of the methods took advantage of the normalized apparent mass from published papers to take the place of the human model, while the other two methods made use of one measured seat transmissibility with a subject to deduce the apparent masses of all the subjects. Good agreement was illustrated between the experiment and model prediction for all the four methods. In addition, it also exhibited that a large discrepancy can be resulted in, especially in the high-frequency range, if the seat model was substituted by one integrated dynamic stiffness.

A Machine for Developing a World View

This article examines hand written school press publications of the beginning of the 20th century. It is based on a text collection of school manuscript journals and newspapers from two St Petersburg schools: the VyborgEight-yearCommercialSchool and Vvedenskaya Boys’ ClassicalSecondary School. In this article the texts are considered as a social act, i.e. as one of the mechanisms of this kind of socialization, and not only as an indicator of latter. According to the schoolchildren themselves, one of the goals of the school press was to form a world view. This article conducts a short review of how the idea of a world view has developed in Russia during the 19th century. Furthermore, the article examines the practices which have been used by the school press in order to form a world view. The article also examines those conditions which have been created in the school press: the active students struggling against an inert mass, censure and also self-censure in the school press. The findings provide a new source for microhistorical research that investigates the peculiar features of socialization typical of the Russian intelligentsia at the turn of the 19th–20th centuries. In the conclusion, the author attempts to widen our understanding of the beginning of the 20th century.

Bose–Einstein condensation of dressed photons in a nonlinear optical microcavity

Bose–Einstein condensation (BEC) of dressed photons in a Kerr nonlinear optical microcavity is investigated. Our experimental scheme is based on an optical microcavity filled with a Kerr nonlinear nonpolar crystal. The pump photons interact with the Raman phonons in the crystal and hence are converted into new quasiparticles, which we refer to as dressed photons. A dressed photon is a photon dressed with a cloud of virtual transverse-optical phonons. The first main finding is that two-dimensional (2D) dressed photons have an increased inert mass. The second main finding is that the lower cutoff frequency of a nonlinear optical microcavity becomes larger. The third main finding is that the incident laser intensity is a moderate laser intensity ([Formula: see text]10[Formula: see text] W/cm2). The fourth main finding is that the critical optical power of a nonlinear optical microcavity is increased. The fifth main finding is that the radiation emitted by 2D dressed photons has an ultrahigh intensity.

A Theory of Inertia Based on Mach’s Principle

A non-relativistic theory of inertia based on Mach’s principle is presented as has been envisaged, but not achieved, by Ernst Mach in 1872. The central feature is a space-dependent, anisotropic, symmetric inert mass tensor. The contribution of a mass element d m to the inertia of a particle m 0 experiencing an acceleration from rest is proportional to cos 2 α , where α is the angle between the line connecting m 0 and d m and the direction of the acceleration. Apsidal precession for planets circling around a central star is not a consequence of this theory, thereby avoiding the prediction of an apsidal precession with the wrong sign as is done by Mach-like theories with isotropic inert mass.

Adipogenesis: A Necessary but Harmful Strategy

Obesity is considered to significantly increase the risk of the development of a vast range of metabolic diseases. However, adipogenesis is a complex physiological process, necessary to sequester lipids effectively to avoid lipotoxicity in other tissues, like the liver, heart, muscle, essential for maintaining metabolic homeostasis and has a crucial role as a component of the innate immune system, far beyond than only being an inert mass of energy storage. In pathophysiological conditions, adipogenesis promotes a pro-inflammatory state, angiogenesis and the release of adipokines, which become dangerous to health. It results in a hypoxic state, causing oxidative stress and the synthesis and release of harmful free fatty acids. In this review, we try to explain the mechanisms occurring at the breaking point, at which adipogenesis leads to an uncontrolled lipotoxicity. This review highlights the types of adipose tissue and their functions, their way of storing lipids until a critical point, which is associated with hypoxia, inflammation, insulin resistance as well as lipodystrophy and adipogenesis modulation by Krüppel-like factors and miRNAs.

A Theory of Inertia Based on Mach's Principle

A non-relativistic theory of inertia based on Mach's principle is presented as has been envisaged but not achieved by Ernst Mach in 1872. Central feature is a space-dependent, anisotropic, symmetric inert mass tensor. The contribution of a mass element $dm$ to the inertia of a particle $m_0$ experiencing an acceleration from rest is proportional to $\cos^2\alpha$, where $\alpha$ is the angle between the line connecting $m_0$ and $dm$ and the direction of the acceleration. Apsidal precession for planets circling around a central star is not a consequence of this theory, thereby avoiding the prediction of an apsidal precession with wrong sign as is done by Mach-like theories with isotropic inert mass.