scholarly journals Reasoning of additional diagnostic parameters for electric insulation diagnostics by absorption methods

2021 ◽  
pp. 39-45
Author(s):  
V.M. Kyrylenko ◽  
K.V. Kyrylenko ◽  
M.O. Budko ◽  
P.L. Denysiuk
Keyword(s):  
Time Constant ◽  
Practical Significance ◽  
Time Interval ◽  
Technical Diagnostics ◽  
Absorption Coefficients ◽  
Absorption Time ◽  
Diagnostic Parameters ◽  
Electric Insulation ◽  
Local Character ◽  
Leakage Resistance

The aim of this work is to analyze the inadequacies of the diagnostic parameters, in particular the absorption and polarization coefficients, which are manifested in their integral character and dependence on the ratio of values of several elements of the equivalent scheme of insulation replacement. This article contains the results of theoretical investigation of the extremе nature of the absorption diagnostic parameters, which leads to unambiguity of the diagnostics procedure. The ways of partial adjustment of this unambiguity have been proposed. Methodology. To determine the extremality of the absorption coefficients depending on the absorption time, absorption capacity and resistance, as well as the leakage resistance, the usual method of investigating the functions was used, detailed calculations have been obtained by using MATLAB software. Results. Has been shown that the ambiguity of diagnostic results is caused by the contradiction of the integral character of the diagnostic parameters and the local character of the isolation failures, in particular breakdown, by ambiguous dependence of the diagnostic parameters on the values of the elements of the insulation replacement scheme and the extremal nature of the diagnostic parameters. Based on the general expression describing all currently used absorption coefficients, it is shown that they all have an extremum, the value of which depends on the parameters of the insulation substitution scheme and the time interval between the measurements of the absorption current. The dependence of the extreme value of the absorption and polarization coefficients on the parameters of the insulation substitution scheme has been established. Has been shown that to eliminate the ambiguity caused by the extremity of the absorption coefficients, it is necessary to introduce additional diagnostic parameters, such as the ratio of leakage resistance to absorption resistance, as well as the critical value of the absorption time constant. Originality. The detailed analysis of the reasons of ambiguity of electric insulation technical diagnostics by absorption methods has been carried out. A method for eliminating the ambiguity caused by the extremity of the absorption coefficients has been proposed. Practical significance. To eliminate the ambiguity caused by the extremity of the absorption coefficients, additional diagnostic parameters are proposed – the ratio of leakage resistance to the absorption resistance and critical values of the absorption time constant. The applying of these parameters with the absorption coefficients will more adequately assess the technical condition of insulation.

scholarly journals Elastic, inelastic and time constant measurement for M102 (AL–C–O) dispersions-reinforced aluminum alloys

2020 ◽  
pp. 61-66
Author(s):  
Khaleel Abushgair
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Time Constant ◽  
Room Temperature ◽  
Strain Range ◽  
Time Interval ◽  
Cnc Milling ◽  
Plastic Deformations ◽  
Factors Affecting ◽  
Bulk Content

Purpose. To conduct an experimental study on M102 aluminum alloy bulk content characterization under cyclic loadings for precision applications such as balance machines, optical, and laser instruments. M102 (AL-C-O) dispersion-reinforced aluminum alloy was chosen because of its ability to withstand temperatures beyond 200C and has a better strength than precipitation-hardened Al alloys at room temperature. A CNC milling machine is used to manufacture test samples with longitudinal machining directions. A constant time interval is set for the fabric a quarter-hour span, which is based on the investigation of inelastic and plastic deformations in the nanoscale. Methodology. An electromagnetic test instrument applies a tensile stress range of 10 to 145 N/mm2 to samples with particular shape. It should be noted that interferometers and capacitive sensors were used to measure all forms of deformations with and without loading. The experiments are carried out in a temperature-stable environment of 30.5 C; measurements are taken within a residual strain range of 10 microns. Findings. The results obtained show that results for inelastic deformations for samples of longitudinal cuts direction at 30.5 C were measured under 150 N/mm2 stress as 500 nm inelastic deformation and 100 nm plastic deformation were measured, which is much higher than aluminum alloy studied before at room temperature (20 C). Furthermore, it was found that the time constant of the M102 (ALCO) aluminum alloy samples was double times higher than that for other samples, Originality. For the first time, a study has been conducted on inelastic and plastic deformations in the nanoscale for characterization of M102 aluminum alloy bulk content under cyclic loadings for precision applications. Practical value. One of the main factors affecting the using of other materials than steel in precision applications such as balance machines, optical, and laser instruments is measurement and determination of inelastic, plastic and time constant of the process of delamination of materials of different aluminum alloys since they are nonmagnetic, are easily machined and shaped. This will bring new products and opportunities for these materials.

Intellectual Capital of Technological Transformation of Economy of Industrial Region

2021 ◽  
Vol 20 (4) ◽  
pp. 641-665
Author(s):  
A.A. Chursin ◽  
◽  
A.V. Yudin ◽  
P.Yu. Grosheva ◽  
◽  
...  
Keyword(s):  
Intellectual Capital ◽  
Industrial Development ◽  
Technological Development ◽  
Practical Significance ◽  
High Tech ◽  
Time Interval ◽  
Technological Transformation ◽  
Industrial Region ◽  
Technological Structure ◽  
Industrial Regions

The relevance of the research topic is due to the need to strengthen and expand the technological transformation of the Russian economy, which should contribute to the growth of high-tech products production and increase the competitiveness of domestic manufacturers in the world market. The hypothesis of the study is that the component features of the intellectual capital of the industrial region determine the predisposition/absence of predisposition of its economy to make a transition to a new dominant technological structure. The purpose of the scientific research is to identify the types of intellectual capital and which of them form the predisposition of regions to the technological transformation of their economies. During the study, the following tasks were solved: structural elements of intellectual capital that affect the innovative and technological development of the region, namely: education, are justified; innovative competencies; innovative skills; altruism; cognitive and non-cognitive competencies; sensitivity to change and adaptation to technological changes. Extractive, mono-inclusive and multi-inclusive type of intellectual capital of industrial regions, corresponding to the fourth, fifth and sixth technological framework, respectively, is disclosed. A methodology for estimating intellectual capital, which determines the dominant technological structure of the economy of the industrial region, has been developed on the basis of the use of the matrix method and Frobenius norms, which make it possible to conduct research over a long-time interval taking into account the dynamic trends of the main capital elements. The testing of the author's methodology revealed that such territories as Kemerovo Region, Nizhny Novgorod Region, Perm Territory, Republic of Bashkortostan, Republic of Tatarstan, Sverdlovsk Region, Udmurt Republic, Chelyabinsk Region, Chuvash Republic and Yaroslavl Region have intellectual capital for further technological development of the region's economy. The novelty of the obtained results lies in the development of a typology of regions, which enables one to identify the territories most prone to further technological transformation of the economy in the context of types of intellectual capital. The practical significance of the results obtained lies in the possibility of their use by authorities as a tool for developing a strategy for industrial development and structural adjustment of the economy of industrial regions.

scholarly journals Voltage Spectral Structure as a Parameter of System Technical Diagnostics of Ship Diesel Engine-Synchronous Generators

2015 ◽  
Vol 8 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Aleksandrs Gasparjans ◽  
Aleksandrs Terebkovs ◽  
Anastasia Zhiravetska
Keyword(s):  
Diesel Engine ◽  
Spectral Power ◽  
Angular Acceleration ◽  
Piston Compressor ◽  
Technical Condition ◽  
Electric Machine ◽  
Technical Diagnostics ◽  
Spectral Structure ◽  
Diagnostic Parameters

Abstract A method of technical diagnostics of ship diesel engine – generator installation – is proposed. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. A judgment on the quality of the operational processes in diesel engine cylinders and its technical condition is possible on the basis of these parameters. This method is applicable to piston compressor installations with electric drive. On the basis of such parameters as rotating torque, angular speed and angular acceleration it is possible to estimate the quality of the operating process in the cylinders of a diesel engine, the condition of its cylinder-piston group and the crank gear mechanism. The investigation was realized on the basis of a diesel-generator with linear load. The generator operation was considered for the case of constant RL load. Together with the above mentioned, the condition of bearings of synchronous machines, uniformity of the air gap, windings of the electric machine were estimated during the experiments as well. The frequency spectrum of the stator current of the generator was researched and analyzed. In this case the synchronous machine is becoming a rather exact multipurpose diagnostic sensor. The signal of non-uniformity in the operation process of diesel engine cylinders and its technical condition is the increasing of the amplitudes of typical frequencies.

Interrelation between Restitution Time-Constant and Alternating Myocardial Contractility in Dogs

1970 ◽  
Vol 39 (5) ◽  
pp. 625-639 ◽  
Author(s):  
Y. Mahler ◽  
S. Rogel
Keyword(s):  
Time Constant ◽  
Exponential Function ◽  
Myocardial Contractility ◽  
Heart Block ◽  
Complete Heart Block ◽  
General Rule ◽  
Single Equation ◽  
Time Interval ◽  
Force Of Contraction

1. In open chest dogs with complete heart block the ventricles were stimulated electrically at various steady rates, and a single premature or delayed beat was interposed to alter myocardial tension. This was followed by transient mechanical alternans. Steady alternans was induced by high stimulation frequencies. 2. It appeared that the recovery of the force of contraction of a beat could be approximated by an exponential function of the preceding time interval. We observed a correlation between the time-constant of this exponential curve and the force of contraction of the previous beat. 3. The results demonstrate that a general rule of mechanical alternans can be expressed by a single equation. This equation describes adequately (1) the duration of transient mechanical alternation produced by a delayed beat, (2) the production of steady alternation at rapid ventricular rates, and (3) the manifestations of post-extrasystolic potentiation during mechanical alternans. 4. Curves relating amplitude of one beat to the successive beat, based on experiments performed in in vivo dog hearts, corresponded to the results predicted by the equation.

scholarly journals ОЦІНЮВАННЯ ЕКОНОМІЧНОЇ БЕЗПЕКИ ОРГАНІЗАЦІЙ НА ОСНОВІ ФОРМУВАННЯ СИСТЕМИ ПОКАЗНИКІВ

2021 ◽  
pp. 34-39
Author(s):  
Костянтин Вікторович Павлов ◽  
Сергій Юрійович Ільїн
Keyword(s):  
Legal Status ◽  
Economic Security ◽  
Practical Significance ◽  
Accurate Information ◽  
Time Interval ◽  
Main Hypothesis ◽  
Organic System ◽  
Integral System ◽  
Statics And Dynamics ◽  
The Impact

The problems of assessing the economic security of organizations on the basis of creating an integral system of final (resulting) and intermediate (factor) indicators related to indicators of determining its level in a state of statics and dynamics, given the current situation in the modern era, seem to be very relevant. The purpose of the study is to form an organic system of indicators economic security, providing organizations with the definition of all reserves of economic growth and identification of advantages over competitors on the basis of the current economic mechanism. The methodological basis of the study was the modern legislative and normative legal acts regulating the economic activities of organizations. Research tasks, goal achievement and problem solving are focused on the use of methods of chain substitutions and mathematical analysis, which, complementing each other, provide accurate information about the degree of influence of factor indicators on the resulting indicators, which is necessary for organizations to rank areas that enhance economic security. The main hypothesis of the study was the assumption about the possibility and feasibility of forming a system of indicators for assessing the economic security of organizations. Presentation of the main material. This article is devoted to the analysis of the approach proposed by the authors to assessing economic security as the core of the economic potential of organizations based on the creation of an integral system of final (resulting) and intermediate (factor) indicators related to indicators of determining its level in a state of statics and dynamics. The originality and practical significance is confirmed by our proposed toolkit, which includes factor and resulting indicators in their organic interaction, which makes it possible to objectively assess the economic security of organizations. The practical significance of the study also lies in the fact that these methods are applicable in all organizations, regardless of their economic and legal status, since they are built on general economic postulates and provide for the specifics of the current economic situation. Conclusions and prospects for further research. Having the tools created by the authors, presented by methods for calculating economic security indicators, organizations will qualitatively analyze its general and particular indicators, objectively assessing the final and intermediate desired benchmarks for the effectiveness and cost of activities and the strength of the impact of each of them on the result and costs, objectively subject to an increment in during a certain time interval. In the future, it is planned to develop and expand the proposed system of indicators for assessing economic security, including using a generalized version of this system in relation to other taxonomic objects at the meso-level - to regions and industries.

scholarly journals TO THE QUESTION OF THE POSSIBILITY OF DEVELOPING TOOLS AND METHODS FOR INSTRUMENTAL DIAGNOSTICS OF HEAT EXCHANGERS OF TRANSPORT EQUIPMENT IN OPERATION

2021 ◽  
pp. 60-67
Author(s):  
A.P. Poslavsky ◽  
◽  
V.V. Sorokin ◽  
A.A. Fadeev ◽  
◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Objective Assessment ◽  
Operating Time ◽  
Basic Structure ◽  
Technical Condition ◽  
Practical Significance ◽  
Time Interval ◽  
Problem Situation ◽  
Resource Saving ◽  
Diagnostic Support

Heat exchangers are used to stabilize and maintain the temperature regime of various units and systems of cars. The technical condition of heat exchangers in operation is different and unstable. At a certain operating time interval, the technical condition of any of the heat exchangers can become limiting due to the influence of various kinds of operational factors. The article analyzes the possibility of improving the means and methods of diagnostic support of automobile heat exchangers in operation. In the design and manufacture of automotive heat exchangers, they are tested in specialized laboratories equipped with test stands characterized by high capital and operating costs. The use of these stands for diagnosing heat exchangers in operation is not applicable. Due to the limitations and imperfections of the known methods and means of diagnosing automobile heat exchangers in operation, an objective assessment of their current technical condition is difficult and requires the search for new, more advanced diagnostic options. The relevance of the topic of the article lies in the search for ways to improve the diagnostic support, adapted for a quantitative assessment of the technical condition of heat exchangers in operation. The aim of the work is to improve the method and means of diagnosing heat exchangers in operation on the basis of modernizing the design of the test bench for radiator modules. Potentially a possible upgrade option was chosen previously developed by the authors stand for testing modules of automobile radiators, which is distinguished by the effect of resource saving when obtaining the test result. Achievement of the goal requires updating the architecture of the structural elements of the stand, and the search for design and technological solutions that contribute to the achievement of the goal. The methodological research toolkit is based on dialectically interrelated methods: analysis of a problem situation and subsequent design and technological synthesis. Scientific novelty lies in the development of conditions for modernization, allowing to expand the functionality of the basic structure of the stand. The practical significance of the results lies in the choice of the direction of research, with a new set of technical proposals and conditions for achieving the goal of the work.

scholarly journals DEVELOPMENT OF METHODS FOR NONDESTRUCTIVE TESTING OF INTERNAL COMBUSTION ENGINE FUEL EQUIPMENT

2020 ◽  
Author(s):  
Г.Д. КОКОРЕВ ◽  
Е.А. ЖУРАВЛЕВА
Keyword(s):  
Internal Combustion Engines ◽  
Fourier Transforms ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Time Interval ◽  
Technical Diagnostics ◽  
Engine Fuel ◽  
Mechanical Parameters ◽  
Destructive Testing ◽  
The Relationship

В исследовании рассмотрены некоторые составляющие технической эксплуатации автомобильной техники (АТ), связанные с диагностированием топливной аппаратуры двигателей внутреннего сгорания (ДВС), причем с целью осуществления неразрушающего контроля предлагается применять ультразвуковую и акустико-эмиссионную системы технического диагностирования.Необходимо констатировать, что при рассмотрении соотношений, показывающих взаимосвязь акустических и физико-механических параметров материалов, в основном используется временной интервал, и при его некорректном измерении получаем низкую информативность и невысокую точность акустических методов определения механических характеристик. При разработке методики использованы принципы спектрального анализа импульсов, отраженных от исследуемых элементов АТ, на которых опирается также метод разработки как аппаратного так и программного обеспечения для обработки полученных сигналов. Результаты предыдущих исследований дают основание полагать, что применение преобразований Фурье обеспечивает получение достоверной информации, основанной на акустических сигналах, если последовательность измерений составляет около 10 секунд. Опыт разработчиков системы свидетельствует о высокой информативности параметров распространения рэлеевских волн. В связи с этим система была укомплектована специально разработанным малобазным датчиком рэлеевских волн. Регистрированные отраженные сигналы в последующем обрабатываются пакетом прикладных программ. Данный преобразователь может быть эффективно использован в задачах контроля накопления повреждений в материале элементов АТ, подвергаемых упруго-пластическим и усталостным воздействиям.Принцип действия системы основан на стробоскопическом эффекте восстановления отраженных импульсов, которые получаются в результате «облучения» материала обследуемого элемента АТ зондирующими импульсами в указанной полосе частот. The study considers some components of technical operation of automotive equipment (at) related to the diagnosis of fuel equipment of internal combustion engines, and for the purpose of non-destructive testing, it is proposed to use ultrasonic and acoustic emission systems for technical diagnostics. It should be noted that when considering the relations showing the relationship between acoustic and physical-mechanical parameters of materials, the time interval is mainly measured, and if the measurement is incorrect, the relationship between the acoustic and physical-mechanical parameters of the material often gives low information content and low accuracy of acoustic methods for determining mechanical characteristics. When developing the technique, the principles of spectral analysis of pulses refl ected from the studied at elements are used, which also support the method of developing both hardware and software for processing the received signals. The results of previous studies suggest that the use of Fourier transforms provides reliable information based on acoustic signals, if the measurement sequence is about 10 seconds. The experience of the system developers shows that the parameters of Rayleigh wave propagation are highly informative. In this regard, the system was equipped with a specially developed low-base relay wave sensor. The registration of refl ected signals is then processed by a package of application programs. This Converter can be effectively used in the tasks of monitoring the accumulation of damage in the material of at elements subjected to elastic-plastic and fatigue effects. The principle of operation of the system is based on the stroboscopic effect of recovery of refl ected pulses, which are obtained as a result of "irradiation" of the material being examined by the at element with probing pulses in the specifi ed frequency band.

Control of Dynamic Objects in the Conditions of Uncertainty in the Point Sliding Mode

2019 ◽  
Vol 20 (12) ◽  
pp. 714-722
Author(s):  
G. A. Rustamov ◽  
M. B. Namazov ◽  
A. Y. Gasimov ◽  
R. G. Rustamov
Keyword(s):  
Finite Number ◽  
Sliding Mode ◽  
Practical Importance ◽  
Practical Significance ◽  
Switching Frequency ◽  
Time Interval ◽  
Initial State ◽  
Classical Formulation ◽  
Sliding Motion ◽  
Switching Line

There is development of the well-known sliding mode, which in the classical formulation didn’t find the development to be applied to control systems discussed. Alternatively, there is method of organizing one of the uniformity of the sliding mode called the "point sliding mode" proposed. The distinctive feature of this mode is that here the control gaps occur at time-equal points of the switching line (hyperplane) which allows the origin of coordinates for a finite number of switches. The possibility of changing the time interval between these points makes it possible to obtain various modes: a finite mode, in which a given point is reached from any initial state in one switch, and in this mode the switch line is "isochronous"; point sliding mode in which a given point is reached in a finite number of switchings; limit mode, when the length of time intervals tend to zero, and the switching frequency to infinity. Considering this feature the concept of "degree of slip" is introduced. It is shown that in the case of forced movement in the SPS, a sliding motion is observed, which does not allow for ensuring invariance with respect to external disturbances. There are two ways to eliminate the forced component of the movement offered. One of the advantages of using a point sliding mode is that, in order to improve performance, it is not necessary to use a boundary layer, which is realized by entering various logical conditions into the control algorithm. The practical significance of a point sliding mode lies in the fact that, with a small switching frequency, it is possible to maintain the quality indices of an undefined object within an acceptable interval. The studies were conducted for onedimensional second-order linear systems (SISO). Results can be generalized for higher order multidimensional systems. Solution of model problems on MATLAB / Simulink allows us to make a number of positive conclusions that are of great practical importance in terms of expanding the area of use of skipping modes, especially in relation to the management of undefined objects.

scholarly journals Body sway adaptation to addition but not withdrawal of stabilizing visual information is delayed by a concurrent cognitive task

2017 ◽  
Vol 117 (2) ◽  
pp. 777-785 ◽  
Author(s):  
Jean-Louis Honeine ◽  
Oscar Crisafulli ◽  
Marco Schieppati
Keyword(s):  
Time Constant ◽  
Visual Information ◽  
Time Course ◽  
Sensorimotor Integration ◽  
Cognitive Task ◽  
Rapid Onset ◽  
Body Sway ◽  
Time Interval ◽  
Arithmetic Task ◽  
Cortical Level

The aim of this study was to test the effects of a concurrent cognitive task on the promptness of the sensorimotor integration and reweighting processes following addition and withdrawal of vision. Fourteen subjects stood in tandem while vision was passively added and removed. Subjects performed a cognitive task, consisting of counting backward in steps of three, or were “mentally idle.” We estimated the time intervals following addition and withdrawal of vision at which body sway began to change. We also estimated the time constant of the exponential change in body oscillation until the new level of sway was reached, consistent with the current visual state. Under the mentally idle condition, mean latency was 0.67 and 0.46 s and the mean time constant was 1.27 and 0.59 s for vision addition and withdrawal, respectively. Following addition of vision, counting backward delayed the latency by about 300 ms, without affecting the time constant. Following withdrawal, counting backward had no significant effect on either latency or time constant. The extension by counting backward of the time interval to stabilization onset on addition of vision suggests a competition for allocation of cortical resources. Conversely, the absence of cognitive task effect on the rapid onset of destabilization on vision withdrawal, and on the relevant reweighting time course, advocates the intervention of a subcortical process. Diverting attention from a challenging standing task discloses a cortical supervision on the process of sensorimotor integration of new balance-stabilizing information. A subcortical process would instead organize the response to removal of the stabilizing sensory input. NEW & NOTEWORTHY This study is the first to test the effect of an arithmetic task on the time course of balance readjustment following visual withdrawal or addition. Performing such a cognitive task increases the time delay following addition of vision but has no effect on withdrawal dynamics. This suggests that sensorimotor integration following addition of a stabilizing signal is performed at a cortical level, whereas the response to its withdrawal is “automatic” and accomplished at a subcortical level.

scholarly journals Assessment of vehicle damage from the point of a complex technical system with its own structure

2021 ◽  
Vol 1 (3) ◽  
pp. 42-48
Author(s):  
I.I. Tupitsyn ◽  
◽  
S.G. Zubris'kiy ◽  
P.A. Krasavin ◽  
◽  
...  
Keyword(s):  
Contact Point ◽  
Grid Method ◽  
Technical System ◽  
Measuring Instruments ◽  
Time Interval ◽  
Diagnostic Parameters ◽  
Different Types ◽  
Complex Technical System ◽  
Method Of Assessment ◽  
The Given

There is considered a part of the study of post-repair reliability of vehicles from the point of a complex technical system in the form of an algorithm for evaluating diagnostic parameters (probable connections). The problem of the reliability of vehicles in operation is legally put under the control of the President of the Russian Federation and is included in the strategy for ensuring road safety until 2023, which is part of the National Project “Safe Roads”. The initial data of the study at the stage of evaluating probable connections are the parameters of the vehicle movement in the pre-accident time interval and the voltage acting at the contact point of the object, which is obtained based on these parameters. The main method of assessment is the cal-culation of cells of different types using the grid method, depending on the nature of the damage to the vehicle. In order to decompose the contact point into cells of different types, it is recommended to use appropriate certified measuring instruments and certified equipment: flaw detectors and so on. For the convenience of using the algorithm and reducing the error of using the given mathemat-ical model in a comprehensive assessment of the reliability of vehicles, the article provides a defini-tion of the reduced volume and correction coefficients. The output data of the algorithm for evaluating diagnostic parameters are the updated values of stresses at the contact point of the object under study, as well as a detailed picture of the distribution of strain energy in the object. As a result, the obtained values can be used for further evaluation of changes in the regulated values of the vehicle properties established by the manufacturer and controlled within the framework of the failure prevention system or technical inspection.

Sign in / Sign up

Export Citation Format

Share Document