Effects of the Ankle Flexion Angle During Anterior Talofibular Ligament Reconstruction on Ankle Kinematics, Laxity, and In Situ Forces of the Reconstructed Graft

Background: This study aimed to evaluate the effects of the ankle flexion angle during anterior talofibular ligament (ATFL) reconstruction on ankle kinematics, laxity, and in situ force of a graft. Methods: Twelve cadaveric ankles were evaluated using a 6–degrees of freedom robotic system to apply passive plantar flexion and dorsiflexion motions and multidirectional loads. A repeated measures experiment was designed using the intact ATFL, transected ATFL, and reconstructed ATFL. During ATFL reconstruction (ATFLR), the graft was fixed at a neutral position (ATFLR 0 degrees), 15 degrees of plantar flexion (ATFLR PF15 degrees), and 30 degrees of plantar flexion (ATFLR PF30 degrees) with a constant initial tension of 10 N. The 3-dimensional path and reconstructed graft tension were simultaneously recorded, and the in situ force of the ATFL and reconstructed grafts were calculated using the principle of superposition. Results: The in situ forces of the reconstructed grafts in ATFLR 0 degrees and ATFLR PF 15 degrees were significantly higher than those of intact ankles. The ankle kinematics and laxity produced by ATFLR PF 30 degrees were not significantly different from those of intact ankles. The in situ force on the ATFL was 19.0 N at 30 degrees of plantar flexion. In situ forces of 41.0, 33.7, and 21.9 N were observed at 30 degrees of plantar flexion in ATFLR 0, 15, and 30 degrees, respectively. Conclusion: ATFL reconstruction with the peroneus longus (PL) tendon was performed with the graft at 30 degrees of plantar flexion resulted in ankle kinematics, laxity, and in situ forces similar to those of intact ankles. ATFL reconstructions performed with the graft fixed at 0 and 15 degrees of the plantar flexion resulted in higher in situ forces on the reconstructed graft. Clinical Relevance: Fixing the ATFL tendon graft at 30 degrees of plantar flexion results in an in situ force closest to that of an intact ankle and avoids the excessive tension on the reconstructed graft.

APLICATION OF THE GAUSSIAN MODEL IN RESEARCH SPREADING AIR POLLUTION

The article deals with the application of the Gaussian distribution for calculating the concen-tration of pollutants. When using the principle of superposition, we have the opportunity to obtain models for calculating the concentration of impurities from a point source of continuous action, in-stantaneous areal and instantaneous volumetric sources. The obtained standard deviations make it possible to assess the effect of air turbulence on the dispersion of pollutants. The first Gaussian model allows one to obtain a diffusion model of a local small-scale space and make predictions, then, based on the Gaussian model of the study, a modified model is obtained for other reliefs and weather conditions. Therefore, the modeling accuracy and applicable conditions are difficult to cope with the needs of large-scale complex meteorological conditions of air quality models.

Obtainment of Residual Stress Distribution from Surface Deformation under Continuity Constraints for Thinned Silicon Wafers

Precision machining (e.g., fine grinding, polishing) induced residual stress is very small and often not constant across the wafer and it is difficult to be directly obtained by stress testing equipment or Stoney equation. The residual stress could be obtained theoretically based on the principle of superposition in which the entire wafer deformation is taken as the sum of all deformations induced by the residual stresses of different positions on the wafer surface. However, the solved residual stress is affected greatly by deformation measurement errors and fluctuates greatly across the wafer surface. To solve the problem, a regularization method with continuity constraints was proposed in this study. The mechanisms for the discontinuity of the residual stress distribution and the sensitivity of calculation results to the measurement errors were studied. The influences of the number of subareas of the silicon wafer were investigated and the continuity constraint term was constructed based on the positional relationship of different subareas. Stable and continuous residual stress distribution was successfully obtained after using the proposed regularization method. The method may also be applied to estimate the residual stress from surface deformation for thin substrate plates of other materials.

Strip yield model for multiple straight cracks with coalesced yield zones: A theoretical study

The paper presents a complicated case of coalescence of yield zones between two internal cracks out of four collinear straight cracks weakened an infinite isotropic plate. Two solutions are presented for the case of opening and closing of multiple cracks under general yielding conditions. Using these two solutions and the principle of superposition, we found the analytical expressions for load-bearing capacity of the plate using complex variable method. A numerical study has been carried out to investigate the behavior of yield zone length concerning remotely applied stresses at the boundary of the plate and the impact of two outer cracks on the propagation of inner cracks due to coalesced yield zones. Results obtained are reported graphically.

Conical Statistical Optimal Near-Field Acoustic Holography with Combined Regularization

For the sound field reconstruction of large conical surfaces, current statistical optimal near-field acoustic holography (SONAH) methods have relatively poor applicability and low accuracy. To overcome this problem, conical SONAH based on cylindrical SONAH is proposed in this paper. Firstly, elementary cylindrical waves are transformed into those suitable for the radiated sound field of the conical surface through cylinder-cone coordinates transformation, which forms the matrix of characteristic elementary waves in the conical spatial domain. Secondly, the sound pressure is expressed as the superposition of those characteristic elementary waves, and the superposition coefficients are solved according to the principle of superposition of wave field. Finally, the reconstructed conical pressure is expressed as a linear superposition of the holographic conical pressure. Furthermore, to overcome ill-posed problems, a regularization method combining truncated singular value decomposition (TSVD) and Tikhonov regularization is proposed. Large singular values before the truncation point of TSVD are not processed and remaining small singular values representing high-frequency noise are modified by Tikhonov regularization. Numerical and experimental case studies are carried out to validate the effectiveness of the proposed conical SONAH and the combined regularization method, which can provide reliable evidence for noise monitoring and control of mechanical systems.

Increasing the Efficiency of OEC with Use of Principle of Superposition and Thereby Increase Share of Wave Energy in Renewable Energy Resources

The quest for new renewable resources is at pinnacle in recent times. We have majorly 3 approaches Viz. [1] Finding new type of renewable resource. [2]Increase the use of already available renewable resources. [3] Increase the efficiency of prime movers so as to increase net power output by available quantity of renewable resources. This paper throws the light on unique idea of integrating the principle of superposition of waves and WEC. WEC or Wave Energy Convertor is a type of prime mover which was devised by OCEANLINX based in Australia. It basically works on compression of air column due to water column. The main drawback of wave energy is that it cannot be used in areas where waves are short and possess less energy. The new idea projected in this paper mainly addresses this issue and thus imparting the power to nations whose geographical location offers them generally short waves. Now they can also generate green energy and thus pushing world towards achieving goals of sustainable development.

СИНТЕЗ СИСТЕМ УПРАВЛІННЯ ЕЛЕКТРОПРИВОДАМИ З КОВЗНИМИ РЕЖИМАМИ

Synthesis of electric drive control systems by methods of the theory of analytical design of optimal controllers (ACOR) allows to obtain structures with sliding modes, which are characterized by high dynamic performance and the property of roughness relative to parametric and coordinate perturbations. At the same time, due to the presence of a relay regulator operating in sliding mode, such systems are nonlinear, described by differential equations with a discontinuous right-hand side. At the same time, one of the problems of ACOR is the problem of choosing the weights of optimizing functionals, which has not received an acceptable solution for designers: the choice of these coefficients is not predetermined by physically clear recommendations. If in the linear case the selection of weights of quadratic criteria can be organized by computer simulation of transients in a closed linear system, then in the nonlinear case such an approach is mathematically incorrect. This is due to the well-known fact that for nonlinear systems the principle of superposition is false, and their behavior in contrast to linear depends significantly on the initial conditions. In this regard, choosing as a result of modeling a nonlinear system on a computer those or other seemingly appropriate weights of the relevant criteria, you can get almost inoperable nonlinear system, because under other initial conditions, its behavior can change qualitatively. Surprisingly, this well-known fact in the literature is obscured, although its influence on the behavior of synthesized systems is fundamental.There are methods for constructing optimal systems based on the synthesis of regulators based on setting the desired quality indicators of transients, taking into account the known behavior of the system with a certain characteristic equation. The article substantiates the method of finding the feedback coefficients of the relay controller from the condition of providing the dynamic characteristics of the system, given the desired characteristic equation.

From Schrödinger Equation to Quantum Conspiracy

Schrödinger’s quantum mechanics is a legacy of Hamiltonian’s classical mechanics. But Hamiltonian mechanics was developed from an empty space paradigm, for which Schrödinger’s equation is a timeless (t = 0) or time-independent deterministic equation, which includes his fundamental principle of superposition. When one is dealing Schrödinger equation, it is unavoidable not to mention about Schrödinger ‘s cat. Which is one of the most elusive cats in modern science since disclosed the half-life cat hypothesis in 1935. The cat is alive or not had been debated by score of world renounced scientists it is still debating. Yet I will show Schrödinger ‘s hypothesis is not a physically realizable hypothesis, for which it has nothing for us to debate about. But quantum communication and computing rely on qubit information algorithm, I will show that qubit information logic is as elusive as Schrödinger’s cat. It exists only within an empty space, but not exists within our temporal (t > 0) universe. Since there is always a price to pay within our universe, I will show that every physical subspace needs a section of time ∆t and an amount of energy ∆E to create and it is not free. Although, double slit hypothesis had been fictitiously confirmed that superposition principle exists, but I will show that double-slit postulation is another non-physically realizable hypothesis that had let us to believing superposition principle is actually existed within our time–space. Yet one of the worst coverup must be particles behaved differently within a micro space to justify the spooky superposition principle, which is one of greatest quantum conspiracy in modern science. Nevertheless, the art of quantum mechanics is all about a physically realizable equation, we see that everything existed within our universe, no matter how small it is, it has to be temporal (t > 0) which includes all the laws, principles, and equations. Otherwise, it is virtual as mathematics is since Schrodinger equation is mathematics, but mathematics is not equaled to science. Finally, when science turns to virtual reality for solution it is not a reliable answer. But when science turns to physical reality for an answer it is a reliable solution.

Timoshenko beam and plate non-stationary vibrations

The problems of Timoshenko beams and plates lateral vibrations under the influence of unsteady loads are considered. Both beam and plate is supposed to be unlimited. In case of the plate the problem has been simply studied. The approach to the solution was based on dominant function method and principle of superposition. Integral models of solutions with cores as dominant functions were built which could be analytically found with the help of the Fourier and Laplace integral transforms. Two original analytical methods for Fourier and Laplace transforms were offered and realized. The examples of calculations were given.