ADEQUACY EVALUATION OF THE SYNTHESIS OF MATHEMATICAL MODELS FOR ONE CLASS OF LINEAR DYNAMIC SYSTEMS WITH PARAMETERS, VARIABLE IN TIME AND IN SPACE

The object of research: the authors of this work have synthesized in previous publications a mathematical model of one class of linear dynamic systems with variable parameters in time and space, which includes the system for lifting and lowering a load with a crane in the case of taking into account the influence of longitudinal vibrations that arise in the cable of the lifting mechanism, and shift in time of the moment of inertia of the rotating masses reduced to the motor shaft. Investigated problem: simulation models are synthesized in the Simulink graphical software environment of the MATLAB application package to assess the adequacy of the specified mathematical model. A calculation was carried out using the passport data and characteristics of all components of the crane structure to find the numerical values of the parameters of simulation models, including the electric motor, cable and gearbox. The main scientific results: the results of modeling the dynamics of the electric drive system during acceleration, deceleration, the prevailing velocity are given. By comparing the results obtained on the simulation model with the results of experimental studies of the same class of dynamical systems carried out by other authors, the adequacy of the mathematical models synthesized by the authors of this work is proved. It is proved that the use of the classical equation of the dynamics of the electric drive system, which contains a constant moment of inertia and a constant moment of load, leads to errors in the estimates of the processes accompanying the lifting and lowering of loads by cranes. And this, in turn, does not allow predicting the behavior of the system in various operating modes with sufficient accuracy. The area of practical use of the research results: enterprises of the machine-building industry, specializing in the production, modernization of lifting equipment. Innovative technological product: a simulation model of a crane mechanism, which makes it possible to take into account the influence of longitudinal vibrations that arise in the cable of the hoisting mechanism, and the shift in time of the moment of inertia of the rotating masses reduced to the motor shaft. Scope of application of the innovative technological product: design and development of control systems for electric drives of lifting equipment

First Pass Effect in Patients Treated With the Trevo Stent-Retriever: A TRACK Registry Study Analysis

Background and Objective: The first pass effect (FPE; achieving complete recanalization with a single thrombectomy device pass) has been shown to be associated with higher rates of good clinical outcomes in patients with acute ischemic stroke. Here, we investigate clinical and radiographic factors associated with FPE in a large U.S. post-marketing registry (TRACK, Trevo Stent-Retriever Acute Stroke). Methods: We analyzed the TRACK database (multicenter registry of 634 patients from 23 centers from March 2013 through August 2015), which 609 patients were included in the final analysis. FPE was defined as a single pass/use of device, TICI 2c/3 recanalization, and no use of rescue therapy. Analysis of individual patient data from TRACK were performed to analyze clinical and radiographic characteristics associated with FPE as well-compared clinical outcomes defined as modified Rankin Scale (mRS) score at 30 and 90 days from hospital discharge to the non-FPE group. Results: The rate of FPE in TRACK was 23% (140/609). There was no association between patient demographics and FPE, including age (p = 0.36), sex (p = 0.50), race (p = 0.50), location of occlusion (p = 0.26), baseline NIHSS (p = 0.62), or past medical history. There was no difference in the use of a balloon-guide catheter or general anesthesia (49 and 57% with FPE vs. 47 and 64%, p = 0.63 and p = 0.14, respectively). Clinical outcomes were significantly associated with FPE; 63 vs. 44% in non-FPE patients achieved mRS 0-2 at 90 days (p = 0.0004). Conclusion: Our study showed that achieving complete recanalization with a single thrombectomy pass using the Trevo device was highly beneficial. The most common clinical factors that are used to determine eligibility for endovascular therapy, such as NIHSS severity, location of occlusion or patient age were not predictive of the ability to achieve FPE

Mechanical properties of technical coated fabrics under axial and off-axial tensile tests

In the paper, laboratory tests carried out by the authors with axial (0° - warp, 90° - weft) and off-axial (15°, 30°, 45°, 60°, 75°) tensile and also with biaxial tensile with shear with different load ratios are described. The purpose of the research was to determine the mechanical properties of material used at numerical simulations of membrane structures. Two different types of a technical coated fabrics used in the experiments - with and without Precontraint® technology. To measure the displacement and strain fields on the surface of specimens, the method of digital image correlation has been used. Numerical simulation of technical coated fabrics, imitating carried-out laboratory tests, has been executed with using of software program Ansys Workbench. It is revealed owing to analysis of results of numerical simulations that shear stresses make a significant contribution to the stress-strain state of material in off-axial and biaxial tensile with shear. The possibility of applying several classical criteria for fracture strength of composite materials in order to predict and evaluate the behavior of technical coated fabrics under load is shown

Взаємодія форми правління та політичного режиму Української держави гетьмана П. П. Скоропадського

Мокін І. С.Взаємодія форми правління та політичного режиму Української держави гетьмана П. П. Скоропадського / І. С. Мокін / Актуальні проблеми політики : зб. наук. пр. / редкол. : С. В. Ківалов (голов. ред..), Л. І. Кормич (заст. голов. ред..), Ю. П. Аленін [та ін.] ; МОН України ; НУ ОЮА. – Одеса : Фенікс, 2013. – Вип. 48. – С. 468-477.In the article the correlation rule and state political regime of the Ukrainian state in 1918 and the general features of public-political regime of authoritarian democracy are defined. The fundamental priority of the monarchical form of government, especially in conditions of significant social changes is proved

Techniques in distal access of wide-necked giant intracranial aneurysms during treatment with flow diversion

BACKGROUND: Accessing the normal distal vessel in treatment of wide-necked giant intracranial aneurysms with flow diversion can be difficult. CASE DESCRIPTION: Through illustrative cases, the authors present several useful techniques in distal access of wide-necked giant aneurysms during flow diversion treatment. Obtaining an optimal projection that separates the outflow limb from the aneurysm is most critical. Each of the three techniques described enabled the distal access to giant intracranial aneurysms during treatment with flow diversion. CONCLUSION: The looped-around technique, balloon-assisted technique, and retrograde access are valuable strategies in crossing the aneurysm if direct distal access cannot be obtained

Numerical simulation of an air-supported structure in the air flow

Wind load is often the critical load for air-supported structures. For example, high wind demolished an air-supported tennis court roof in Zhulebino district of Moscow on May 29, 2017. Aerodynamic instability (buffeting, flutter, etc.) can produce excessive slack regions and extremely large deflections. That is why the coupled analysis should be carried out to understanding aeroelastic behavior of air-supported structures under wind loads. The technique of the nonlinear numerical analysis of air-supported structures including fluidstructural interaction (FSI) has been described in the present paper. Numerical simulation of the tunnel test of large-scale air-supported model has been carried out as an example of using this technique. Wind tunnel study is described in the papers1, 2. Experimental deformed shape, pressure coefficients and aerodynamic forces were compared with the results of presented numerical simulation. Computations were carried out with using of commercial code ANSYS 15.0. Some difficulties appeared during simulation process are discussed. An applicability of the proposed technique to the considered problem was confirmed by a good agreement of the experimental and numerical results. Both methods showed that surface wind loads can increase due to deformation of a structure. These conclusions emphasize the importance of researches on wind interaction with air-supported structures

Шляхова вітроелектростанція з муфтою

Шляхова електростанція з муфтою, що складається з контактного дроту, струмознімача, транспортного засобу, дорожнього полотна, горизонтальної перемички, лопатей, електричної підстанції, інерційного накопичувача, ліній передачі до потужної електростанції, радіально-опорних підшипників, опорних стовпів, вітродвигуна його та осей, потужної підстанції, пристроїв випрямлення і стабілізації, лінія передачі до електричної підстанції, при чому до нижньої поверхні горизонтальної перемички закріплений контактний дріт, з'єднаний зі струмознімачем транспортного засобу та/або виходом електричної підстанції генератор, який електрично-з'єднаний з пристроєм стабілізації і передачі енергії, який під'єднаний до входу електричної підстанції, до якої також під'єднана мережа живлення від потужної електростанції, виходи електричної підстанції під'єднані до контактного проводу, через який транспортні засоби, за допомогою бугеля, отримують електроенергію відрізняється тим, що в неї введено осьовий генератор, обмотки осьового генератора, електромагнітна муфта або муфта вільного ходу, причому, осьовий генератор розташовано безпосередньо на вісі вітродвигуна і напряму підключений до інерційного накопичувача

Пристрій для діагностування пневматичної магістралі гальмівної системи електропоїзда

Пристрій для діагностування пневматичної магістралі гальмівної системи поїзда складається із датчика тиску. В нього введено блок задавання значення атмосферного тиску, блок задавання значення тиску у пневматичній магістралі поїзда, блок задавання значення динамічного коефіцієнта в'язкості стисненого повітря, блок задавання значення швидкості звуку у стисненому повітрі, блок задавання значення першого моменту часу, блок задавання значення другого моменту часу, блок диференціювання, цифровий таймер, чотири блоки підсилення сигналу, два компаратори, блок визначення знаку сигналу, мікропроцесор, елемент І, кнопку ініціалізації системи, блок обчислення коефіцієнта зміни тиску за часом, блок обчислення координати точки обриву пневмопроводу та блок виведення інформації