The aim of the study was to prepare SnO2 nanowires via a combination of electrospinning and the sol–gel method from a polyvinylpyrrolidone (PVP)/dimetylformamide (DMF)/ethanol(EtOH)/tin(IV) chloride pentahydrate (SnCl4·5H2O) solution. The morphology, structure and chemical composition of the obtained PVP/SnO2 nanofibers and SnO2 nanowires were examined using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) as well as a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDX). The optical property analysis was performed on the basis of UV–Vis spectra of absorbance as a function of the wavelength, based on which the rated values of band gaps of the fabricated 1D nanostructures were determined. The morphology analysis showed that the obtained amorphous SnO2 nanowires with crystalline protuberances were characterized by a diameter of 50 to 120 nm. Results demonstrated that nanowires with a ratio of 1:1 precursor to polymer in the spinning solution were characterized by the smallest diameter after calcination and the smallest energy gap of 3.3 eV among all investigated samples. The rest of the studied materials were characterized by a larger energy gap (3.8 and 3.9 eV).
Abstract. The problems discussed in the study are connected with evaluation of complex technical systems functioning, in particular, transport systems. It was assumed that evaluation of their functioning depends on fulfilment degree of selected criteria. Therefore, it is important to determine a set of criteria including their type, number and importance. Since the research object is a public city transport system considered to be a sociotechnical system of the type: human (driver) -machine (vehicle) and the environment
The study deals with the problems connected with modeling and simulation of technical objects operation processes carried out within a certain class of complex technical systems. The analyzed system is a city bus transport system. The study presents a method for assessment of unit costs involved in a technical object’s being in selected operational states. One of the subsets of data to be used for modeling the process of a technical object operational state changes, includes data concerning the costs borne by the system when the object is in the analyzed operational states. In order to determine this data, it is often necessary to modify the system of costs registration used in a given operation system. Since it is a very expensive and log process, a method of initial assessment of indispensable data has been proposed, on the basis of a costs registration method and simulation of the operation process. The study also includes basic assumptions of the operation process model, being an important element of the developed method. The assumptions of the operation model have been formulated on the basis of identification of a real operation system of city bus transport system and experimental tests carried out in system.
Complex of remote diagnostics and control of an automobile’s nodes enables to remotely control the state of vehicle’s nodes and diagnose malfunctions; control ecological norms and compliance with traffic regulations. Its implementation will allow diagnostics of intermittent malfunctions due to application of the proposed methods of remote diagnostics of an automobile’s nodes as well as to reduce terms of diagnostics significantly due to application of intellectual system of malfunctions detection and due to possibility to control parameters in real time mode. Implementation of the complex will cut unforeseen idle time of vehicles due to preventive control of the tendencies in nodes parameters changes, and due to executing modern repair or replacement of nodes and units. The complex grants safe local and remote access to data and reports by using WebPortal and VPN technologies with possibility to appoint personal right to every user. Due to application of the elaborated methods and the complex that implements it, one can achieve high rate of economic efficiency due to collection of statistic information under conditions of actual exploitation, diagnostics of emerging malfunctions of various difficulty degrees, and making necessary corrections in the structure of an automobile’s nodes prior to serial production launch.
The article deals with the issues of the spatial direction of measurement, which is optimal in terms of recognition of the state of a particular unit node and preparation of control points for diagnosis. To form a diagnostic feature, the representation of the signal in a rather narrow range has been used, for instance, in the area of one of the harmonics of the fundamental mechanism excitation frequency. To process such signals, an integrated programming environment developed in the style of Microsoft Visual products has been created. To ensure the requirements of optimal vibration analysis, the structure of stationary equipment control systems has been proposed. Analysis of random vibration of the diagnosed object is done using real-time two-channel analyzers. Each analyzer channel has a processor for fast Fourier transform and operational information. The two available channels can allow assessment of the state of the object by special correlation functions. In contrast to the known methods, the established methods of determining the frequency range of defects of various light industry machine nodes differ in taking account size of parts and equipment nodes, and the possibility to use narrow-band filtering. The analysis of possibilities to install vibration sensors has been carried out.
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