A symplectic subgroup of a pseudounitary group as a subset of Clifford algebra

Let Cl1(1,3) and Cl2(1,3) be the subsets of elements of the Clifford algebra Cl(1,3) of ranks 1 and 2 respectively. Recently it was proved that the subset Cl2(p,q)+iCl1(p,q) of the complex Clifford algebra can be considered as a Lie algebra. In this paper we prove that for p=1, q=3 the Lie algebra Cl2(p,q)+iCl1(p,q) is isomorphic to the well known matrix Lie algebra sp(4,R) of the symplectic Lie group Sp(4,R). Also we define the so called symplectic group of Clifford algebra and prove that this Lie group is isomprphic to the symplectic matrix group Sp(4,R).Comment: 10 page

Development of the measuring channel of the pressure distribution system on the surface model of the aircraft during the experiment in the aerodynamic tube

http://aki.nau.edu.ua/wp-content/uploads/%D0%97%D0%B1%D1%96%D1%80%D0%BD%D0%B8%D0%BA-%D1%82%D0%B5%D0%B7-2021.pdfThe development of modern aircraft construction is impossible without accurate aerodynamic tests (weight, drainage, strain gauge, flutter, bench, calibration), because they: allow to determine the aerodynamic properties of all aircraft and their parts; provide an opportunity to study the basic characteristics of the flow, especially when they are combined with methods of theoretical analysis. At the same time, the statistical analysis of the wind tunnel operation mode shows that the main disadvantages of drainage tests are the outdated and cumbersome system for determining the pressure at points with the help of liquid manometers. The expediency of using a strain-resistive semiconductor sensor HoneyWell Ultra Low Pressure Sensors, which has indisputable advantages among others, namely: compactness; the measurement range is 0.01% of the atmospheric pressure. To reduce the temperature error of strain-resistant transducers, the efficiency of using analog compensation devices based on the method of using temperature-dependent resistors is substantiated. The method of digital error compensation and the possibility of its use during modeling of the measuring channel are investigated. The structural scheme of the measuring channel is developed

To determine the stability of the metrobus in unstable driving modes

Recently in many cities of the world began to introduce so-called «metrobus» or BRT (Bus Rapid Transit) systems, which became a cheaper alternative to the metro and other rail transport, in particular trams. The aim of the work is to determine the stability indicators of the metrobus in the transitional traffic modes, in particular when performing such manoeuvres as «steering wheel jerk» and «shuffle». For this purpose, the equations of metrobus plane-parallel motion are supplemented by equations of the links of the road train in the vertical plane by halopilation (tangage, trim) and roll. The critical straight-line speed of the three-link metrobus has been determined, which was 32,06 m/s, and this speed is independent of the corners of the steering wheels of the bus and the trailer links. It has been shown that as the steering wheel angle of the bus increases, the difference in the folding angles of the bus increases, with the second folding angle significantly exceeding the first, especially considering the roll of the metrobus body. It has been established that the greatest rolls and loads of the metrobus axles are those of the last trailer, which is the limiting factor for the critical speed. The lateral accelerations of individual metrobus links and their yaw velocity when performing the manoeuvre «steering wheel jerk» and «shuffle, Sl = 24 m», show that both the bus and the second trailer link are a limiting factor when performing various manoeuvres, but the acceleration value does not exceed the permissible 0.4 g, so its stability under these conditions is ensured

Ascertaining Cut of Indices of Physical Condition of Students of Ivano-Frankivsk

У статті досліджено питання фізичного стану студентської чоловічої молоді міста Івано-Франківська. Оскільки студенти України сьогодні складають науковий, культурний, інтелектуальний потенціал країни, генофонд нації, то проблема збереження й зміцнення їхнього здоров’я є важливою в культурно-освітньому, економічному та соціально-політичному вимірі. Водночас фізичний стан студентів протягом останнього десятиріччя різко погіршився внаслідок поглиблення соціально-економічної, екологічної й демографічної кризи. Мета статті – вивчення показників фізичного стану студентів вищих навчальних закладів міста Івано-Франківська. Експериментально встановлено, що фізичний стан студентів за низкою ознак (рівень і гармонійність фізичного розвитку, функціональний стан основних систем організму та його резервні можливості, рівень захворюваності й фізичної підготовленості) нижчий за встановлені норми. The scientific article is devoted to the physical condition of young male student of Ivano-Frankivsk. As young students in Ukraine today is the scientific, cultural and intellectual potential of the country, the gene pool of the nation, the problem of preservation and strengthening of health of students is an important cultural-educational, economic and socio-political dimension. At the same time, the physical condition of students over the past decade has deteriorated sharply as a result of the deepening socio-economic, environmental and demographic crisis. The aim was to study the performance of the physical condition of students in higher education Ivano-Frankivsk. It was established experimentally that the physical condition of the students on a number of characteristics (level of harmony and physical development, functional state of the main systems of the organism and its backup capabilities, morbidity and physical preparedness) below established standards

Обгрунтування параметрів гідравлічної запобіжної муфти

Створення нових типів машин і механізмів транспортно-технологічних систем і їх приводів сприяє подальшому розвитку народного господарства та розширенню їх номенклатури, підвищенню продуктивності праці за рахунок упровадження досягнень науково-технічного прогресу. Наведено нову конструкцію гідравлічної запобіжної муфти підвищеної чутливості, виведено аналітичні залежності для визначення розрахункового крутного моменту залежно від силових і конструктивних параметрів.Creation of new types of machines and mechanisms of transport and technological systems and their drives contributes to further economic development and expansion of the range, increase productivity through the introduction of scientific and technological progress. New design of hydraulic overload clutch with hypersensitivity has been presented, analytical dependence for determining the estimated torque depending on power and design parameters have been derived

Activin receptor-like kinase 1 inhibits human microvascular endothelial cell migration: potential roles for JNK and ERK.

International audienceActivin receptor-like kinase 1 (ALK1) is an endothelial-specific type I receptor of the TGFbeta receptor family that is implicated in angiogenesis and in the pathogenesis of the vascular disease, hereditary hemorrhagic telangiectasia (HHT). In the absence of a specific ligand, ALK1 cellular functions have been mainly studied through the use of a constitutively active form of this receptor (ALK1ca) and are still debated. We previously reported that ALK1ca inhibits proliferation and migration of human endothelial cells suggesting that ALK1 plays an important role in the maturation phase of angiogenesis (Lamouille et al., 2002, Blood 100: 4495-4501). In the present work, we further analyzed the role of ALK1 in the migration of human dermal microvascular endothelial cell (HMVEC-d) and observed that silencing endogenous ALK1 expression with siRNAs accelerates endothelial cell migration in the wound assay. Further, we demonstrate that ALK1-induced inhibition of migration is Smad-independent. Using a panel of kinase inhibitors, we found that HMVEC-d wound closure was completely inhibited by a JNK inhibitor and to a lower degree by an ERK kinase inhibitor. Further, HMVEC-d wounding induced activation of both JNK and ERK, and these were inhibited by ALK1ca expression. Taken together, these results support a significant role for ALK1 as a negative regulator of endothelial cell migration and suggest the implication of JNK and ERK as mediators of this effect