Solid State Phenomena Vol. 237

Abstract: The dynamic development of devices that use electrical and electronic components makes it necessary to eliminate sources of interference occurring in circuits with systems of this type. These disturbances adversely affect the correct functioning other systems that work together as a network, as well as equipment located in neighbouring systems. The article presents a method of the analysis of the sources of faults occurring in electrical circuits, using a frequency converter. The discussed principle of the operation of the frequency converter and the impact of disturbances generated by these installations are presented in this article. The evaluation methodology of the installation is presented using the requirements of the Harmonized Standards and the authors’ own solutions. The verification of the method was conducted by applying it to a real electrical circuit. The potential sources of electrical faults were identified that were caused by the frequency converters and its circuit. The developed and presented analysis method of the faults sources can be used for evaluating other circuits of this type in which one of subsystems is a frequency converter circuit.

Abstract: The content of unburned carbon in the fly ash is one of the indicators that allow the assessment of the correctness of the process of the combustion of pulverized coal in conventional power plants, as well as the identification of emerging economic usefulness of ash by-products, which are used, among others, as additives for cements [1]. This forces constant quality checks of generated fly ash. Routinely such tests are carried out periodically with use of laboratory equipment. However, technological progress allows the measurements in semi-real-time on the samples of ash taken directly from a stream of air-ash aerosol. Often used methods in commercial analytical equipment are the microwave methods [2]. Other solutions, currently used in conventional power measurement systems, are devices using x-ray and dielectric methods. X-rays and the measurement of the dielectric parameters of the carbon in the ash are used in, for example, SYSKON 201. The method employed in this solution allows the detection of carbon in the ash in the concentration range from 0 to 16%. However, in this technique, the use of radiation sources requires maintenance of certain operating procedures that may pose a barrier to install this type of equipment in some power plants. It is also possible to use photo-acoustic techniques or laser light scattering [3-5]. A photo-acoustic signal is generated by the absorption of radiation by the sample placed in a sealed chamber filled with gas (nitrogen, helium). Radiation absorbed by the sample causes it to heat up and expand the surrounding gas. The heat wave penetrates the surrounding gas, generates heat at a frequency fluctuation in accordance with the frequency modulation of radiation, and causes changes in gas pressure and, consequently, the formation of the acoustic wave recorded by a highly sensitive microphone [6]. Important limitations of the industrial application of this method is the problem of placing the sample in the measuring chamber filled with an inert gas and the high sensitivity of the measuring equipment to external vibration. The presented characteristics of current methods of monitoring the quality of fly ash directly in technological conditions shows that every solution has some limitations that hinder the application in technological lines. Therefore, development work is carried out to develop other simple and effective methods for monitoring the carbon content of fly ash [7, 8].

Abstract: The article presents the results of the influence of geometrical features of defects in materials on the level of identification by the eddy current method. The study involved the inner ring of the tapered roller bearing. Four test defects, located at a constant distance from the inner surface, and a subsurface marker defect were performed in the treadmill of the tested ring. The test defects had a constant cross-sectional area in a perpendicular direction to the surface of the eddy current head. The geometrical features of each defect were the following: shape, the perimeter of the defect projected onto the surface of the ring, and the width and height of the defect projected on the face of the measuring head. The study involved an inner surface (subsurface defect detection) and external surface (the study of surface defects). It has been shown that the shape of the defect affects the level of detection using the eddy current method.

Abstract: Rescue and fire-fighting vehicles and other vehicles used by the fire department, such as tankers and aerial ladder trucks have typically a high centre of gravity. Driving such vehicles involves the danger of transverse stability loss and rolling over. This problem is augmented by inadequate driver experience due to the low mileage of emergency vehicles. The safety of a moving vehicle largely depends on its driving characteristics, which can be studied and compared, and these in turn can be the basis for the evaluation of the vehicle safety with a specific body design.The aim of the study was to develop a set of measuring devices for identifying driving properties for trucks. A dynamics study was conducted using constructed prototype solutions for selected trucks with a high centre of gravity, including emergency vehicles for fire departments. The study was performed during selected standard road tests for determining driveability properties. Three road tests were used to assess the road stability and manoeuvrability of the vehicles: driving in a circle in predetermined conditions, steering wheel jump while driving straight ahead, and braking while driving in a circle. The results of this study allow determining the characteristic values of parameters describing vehicle behaviour in each test and a comparative assessment of their safety in traffic. Moreover, the study constituted a verification of the developed system that can be used for dynamics tests and the evaluation of vehicle safety.

Abstract: The increasing prices of energy and the drive to reduce the emission of greenhouse gases into the atmosphere observed in the recent years have contributed to the intensive development of research on how to reduce the energy consumption of buildings. The confirmations of the current trends are the formal and legal regulations of the European Union that require the buildings to be passive and “zero-energy” in the near future. The introduction of new elements helping one to save energy in the structure of a building requires their formal verification and the confirmation of their safety, effectiveness, and parameters crucial from the point of their application in residential buildings and offices. The authors present an original prototype of an innovative device and a methodology of conducting studies on air-handling units with heat recuperation used in passive and energy-saving buildings. They also discuss the structure and the modus operandi of the system that reconstructs the actual operating conditions of a tested object. The system was used for tests on the tightness of several air-handling units, which also aimed at the verification of their thermal efficiency and the effectiveness of the recuperation of humidity. Air-handling unit tests came from different manufacturers, and they all had the function of heat recuperation. The authors present the results of their investigations that enabled the assessment of the safety of the objects tested, and they also facilitated the comparison of their performance parameters deciding on the energy effect. The tests also formed the foundation for the verification of the developed research system.

Abstract: Currently, nearly 1.5 M tons of different types of glassware are produced in Poland, and the majority of it is used as packaging in the food, cosmetic, and pharmaceutical industries. The article presents a method for testing impact resistance of glassware, which was developed at the ITeE-PIB. The authors also present a prototype of a device for glassware tests, discuss a test procedure applied in such tests, and show the results of verification tests for which a high-speed digital camera was used to record the impact strength and the propagation of cracks in glassware. The device in question has been successfully implemented in an industrial research laboratory.

Abstract: The article presents a description of the impact block shear test method of adhesive joints. Based on ISO 9653 and literature a pendulum machine was upgraded to make impact strength tests of adhesive joints and validation studies were conducted to determine the parameters of instrumentation and block samples. As a result of the experiments a range of the usable length of the adhesive joint and methods of adhesive joints preparation was selected, and it was determined the adopted method of attachment of the sample in the holder and the pendulum durability. A series of tests on adhesive joints were conducted using samples bonded of adhesive composition Epidian 57 with Z1 hardener for one bondline thickness. Preliminary findings from the research will be used in subsequent, relevant research.

Abstract: The article describes the application of the event-driven networked control system (NCS) for impact load monitoring. The main problem in this type of application is measurement synchronization, which should provide full information about the impact in terms of stochastic delays introduced by the network and stochastic characteristics of the actuator. Using the simulation model of the NCS system, the method of solving this particular problem was developed. The results of verification tests for the real object and a synchronized dynamic measurement of signals from resistance strain gauges are presented. The described system can find use in monitoring and fault detection, in tasks connected with dynamics of liquids and gases, acoustics, and the analysis of resistance properties of materials and technical objects. Key words: Networked control system (NCS), event maintenance, event synchronization, impact monitoring, measurement trigger, strain gauge.

Abstract: Functionality, the quality of work and safety are crucial aspects of the design and implementation process for every new mechanical device, including PVD devices. In the case of the latter, these aspects are closely related to the issue of the batch load. The article presents the analysis and implementation of a machine safety system designed for a modular PVD test stand conducted in accordance with the 2006/42/WE Directive on Machinery. The author presents methods for assessing safety levels of implemented functions and indicates the safety level for which the goals set are met. The analysis the authors conducted can be used for any mechanical device that presents safety concerns due to the presence of moving parts.

Abstract: Multi-agent systems are used mainly in IT solutions and control groups of robots. From the point of view of classical control architectures, they are a kind of distributed systems in which nodes perform advanced algorithms, usually associated with the technology of artificial intelligence, and they can be considered as agents. The article describes the multi-agents control system of objects of uniaxial movements. An example of such a system to control a repository with movable racks with electric motors is presented. Each rack acts as an agent through the implemented control of the resources of embedded microcontrollers. Such a system provides high quality control, guaranteeing long-lasting, trouble-free operation while maintaining the safety of both service and stored items.