Why does chronic pulmonary consumption begin at the apex of the lungs?

The mechanical moment the narrowness of the aperturae superiors, as well as the early ossification of the I rib, is not given decisive importance in the setting time

Static repair of multiple cracked beam using piezoelectric patches

This paper addresses the problem of repairing multiple cracked beams subjected to static load using piezoelectric patches. First, the problem is formulated and solved analytically for the case of two cracks that results in ratio of restoring moments produced by employed piezoelectric patches. Since the ratio is dependent only on crack positions but not their depth, the result obtained for case of two cracks has been extended for the case of multiple cracks. This proposition is then validated by finite element simulation where repairing piezoelectric patches are replaced by mechanical moment load equivalent to the restoring bending moments produced by the piezoelectric patches. The excellent agreement between analytical solution and numerical simulation results in case of single and double cracks allows making a conclusion that a piezoelectric patch could productively repair a cracked beam by producing a restoring moment due to its piezoelectricity. Thus, the problem of repairing multiple cracked beam using piezoelectric patches is solved.

The experimental identification method of the dynamic efficiency for frequency regulation algorithms of AEDs

The article proposes and substantiates a method for studying the dynamics of an asynchronous electric drives with frequency control from the input side of the signal for setting the speed of rotation of the electric motor. In this method, a constant speed reference signal is added to a harmonic variable frequency signal. The set of amplitude changes and phase shifts of velocity oscillations are the initial data for identifying the dynamics of the studied control method. The logic of this method is determined by the previously obtained nonlinear transfer function of the link that forms the mechanical moment in the asynchronous electric drive with frequency control. Experiments have shown the dynamic benefits of the drive with positive stator current feedback.

Introduction to chronodynamics

В динамике решаются задачи движения тел в координатной системе отсчета динамический параметр-время (пространство): динамические параметры (сила, импульс, энергия, механический момент) функциональны по отношению к независимым координатам времени (пространства). Как правило, эти функции непрерывны (кусочно непрерывны), поэтому с позиции теории обратных функций им можно построить в соответствие обратные функции: функциональность времени (пространства) от динамических параметров как независимых. Для монотонных функций эти отображения (образ-прообраз) взаимно однозначные. Произведение динамического параметра на координату времени (пространства) является потенциалом, это произведение образа и прообраза. Потенциалу можно поставить в соответствие полный дифференциал. Аналитическое исследование полного дифференциала потенциала в координатной системе динамические параметры-время (пространство) раскрывает картину появления функционального времени (пространства) и функциональных динамических параметров, сопряженных координатному времени (пространству) и динамическим параметрам. В результате этого вырисовываются элементы основ хронодинамики, сопряженно дополняющие динамику до потенциальной динамики. При потенциальном построении динамики функциональность динамических параметров от времени (пространства), раскрываемая законами сохранения в динамике, дополняется функциональностью времени (пространства) от динамических параметров: сколько динамических параметров, соответственно столько функциональных времен (пространств) и функциональных параметров. В обобщенной потенциальной динамике динамическим параметрам и времени (пространству) в динамике ставится в соответствие потенциальные динамические параметры и потенциальные времена (пространства). В результате исследования получено: при гиперболической зависимости динамических параметров от времени (пространства) соответствующие им потенциальные динамические параметры и потенциальные времена (пространства) равны нулю. В этих случаях динамика и хронодинамика становятся взаимными антидинамиками. Исследование потенциальных параметров открывает динамический код связности динамических параметров. In dynamics, the problems of motion of bodies in the coordinate reference system dynamic parameter-time (space) are solved: dynamic parameters (force, momentum, energy, mechanical moment) are functional with respect to independent coordinates of time (space). As a rule, these functions are continuous (piecewise continuous), so from the position of the torus of inverse functions, they can be constructed in accordance with inverse functions: the functionality of time (space) from dynamic parameters, as independent. For monotone functions, these mappings (image-prototype) are one-to-one. The product of a dynamic parameter on the coordinate of time (space) is a potential, it is the product of an image and a prototype, the Potential can be matched with a complete differential. The analytical study of the full potential differential in the coordinate system dynamic parameters-time (space) reveals the picture of the appearance of functional time (space) and functional dynamic parameters conjugated to coordinate time (space) and dynamic parameters. As a result, elements of the basics of chronodynamics are drawn, which complement the dynamics to the potential dynamics. In the potential construction of dynamics, the functionality of dynamic parameters from time (space), revealed by the laws of conservation in dynamics, is supplemented by the functionality of time (space) from dynamic parameters: how many dynamic parameters, respectively, as many functional times (spaces) and functional parameters. In generalized potential dynamics, the dynamic parameters and time (space) in dynamics are matched to the potential dynamic parameters and potential times (space). As a result of the study, it is obtained that if the dynamic parameters are hyperbolically dependent on time (space), the corresponding potential dynamic parameters and potential times (space) are equal to zero. In these cases, dynamics and chronodynamics become mutual anti-dynamics. Investigation of potential parameters opens the dynamic code of connectivity of dynamic parameters.

On the issue of anatomical and pathological changes in the spinal cord under the influence of its compression

The study of spinal cord diseases due to its compression until the last day was a controversial issue. The first authors who studied it, namely Olivier and Louis, expressed the opinion that the suffering of the spinal cord in these cases is directly due to the mechanical moment of pressure. This opinion, however, was not held for long in the sciences. In its place, another appeared, which soon acquired the right of citizenship. Michaud, who worked under the leadership of Charcot, created an "inflammatory theory" according to which the changes found in the compressed spinal cord are nothing more than changes in the inflammatory nature, the source of these changes to inflammatory vertebral diseases is the substance of the brain.

Optimization the shape of the Francis hydraulic turbine

The article presents one of the possible methods for optimizing the blade shape of a Francis radial-axial hydraulic turbine. The method for optimizing the shape of the turbine blade is based on the criterion of the maximum mechanical moment developed by the turbine. The blade shape optimization operation is conventionally divided into two stages. At the first stage of optimization of the blade shape, the analytical expression of the moment developed by the turbine is presented in a Taylor series by variable parameters − the coordinates of the vertices of the characteristic polyhedron of the median surface of the turbine blade. Adding the boundary conditions in the formulation of the optimization problem in the form of equalities − the contact of the median surface of the turbine blade with the turbine hub and rim, as well as conditions in the form of inequalities − the concavity of the greater part the median surface allows to reduce the problem of optimizing the blade shape to a standard linear programming problem. It is proposed to carry out 50−60 similar operations with small steps in the variables − the coordinates of the vertices of the characteristic polyhedron. Thus, it is necessary to move into the zone of optimal values of the coordinates of the vertices of the characteristic polyhedron of the median surface of the blade. At the second stage, it is proposed to continue the search for the optimal values of the coordinates of the vertices of the characteristic polyhedron of the median surface of the blade, applying for this purpose one of the most effective algorithms of genetic optimization.

Reduction of angular velocities of AIST-2D spacecraft using a system of kinetic moment dumping

The efficiency of a magnetic system of kinetic moment dumping in solving the problem of stabilizing Aist-2D spacecraft without using information on angular velocity is investigated. We defined the conditions under which the magnetic moment produced by electromagnets constitutes a useful control mechanical moment. Boundary conditions for preventing emergence of the parasitic moment are also defined. The paper presents the solution of the problem of forming the vector of the kinetic moment of the system “spacecraft + control moment gyro” according to the information on the vector of geomagnetic induction of the Earth. We defined the dependence of the time taken by the algorithm of angular speed reduction on the value and direction of the projections of the vector of spacecraft angular speeds at the time of algorithm actuation. The results obtained in the course of mathematical modeling and natural experiment on the spacecraft, the process of dumping angular speeds in providing the solution of the problem of attitude determination with the use of star sensors are compared.