Photoacoustic and spectrophotometric methods have been applied to evaluate the properties changes of petroleum fuels and oils after oxidation. Samples were oxidated under laboratory and real working condition. The preliminary results of experimental investigations are presented.
Noise-induced pulmonary pathology is still an issue that is regarded with much suspicion despite the significant body of evidence demonstrating that acoustic phenomena target the respiratory tract. The goal of this review paper is threefold: a) to describe acoustic phenomena as an agent of disease, and the inadequacies of current legislation regarding noise-induced, non-auditory pathology; b) to trace how the interest in noise-induced pulmonary pathology emerged within the scope of studies on vibroacoustic disease; and c) to bring to light other studies denouncing noise as an agent of disease that impinges on the respiratory tract. As concluding remarks, future perspectives in LFN-related research will be discussed. The need for animal models will be emphasized.
Aircraft touchdown is one of the most difficult and dangerous phases of a flight.The paper presents an aerial light aircraft, prepared and produced by vibroacoustic tests, using an aircraft landing and landing monitoring system (AVI).The concept is based on the use of an ultrasonic transceiver head and vibration transducer, together with an appropriate signal processing and analysis system.The system measures the touchdown speed and altitude of the aircraft in the final phase of the flight and determines the level of load transmitted to the aircraft during the landing.Thanks to data archiving, it allows for better estimation of the wear rate of the structure, which is important in determining the causes of possible malfunction.It can be used with light and ultralight aircraft and, after adaptation, in unmanned aircraft.It can also be used to evaluate the art of piloting during landing.
An objective method and apparatus for noise control and acoustic diagnostics of motorcar engines are reported. The method and apparatus let us know whether the noisiness of the vehicle under test exceeds the admissible threshold levels given by appropriate standards and if so what is the main source of the excessive noise. The method consists in measuring both the overall noise level and the sound pressure levels in definite frequency bands while the engine speed is controlled as well and may be fixed at prescribed values. Whenever the individually adjusted threshold level has been exceeded in any frequency band, a self-sustaining control signal is sent.
This paper describes a wireless transmission system to be operating on a real bridge structure. The investigated bridge (Fig. 1) is a single-span, 40meter-long, steel truss structure providing support for a single railway track. The program of monitoring of the bridge includes two major issues. First, monitoring of structural health and its potential degradation due to e.g. corrosion is planned. Second, monitoring of railway car mass and speed is of interest to the owner of the railway infrastructure. The monitoring will be performed using piezoelectric strain sensors. Consequently, the proposed integrated monitoring system [1] will consist of two hardware parts. The first part installed nearby an investigated bridge is supposed to weigh trains in motion (Fig. 2). This way the parameters of dynamic load acting on the bridge will be known in contrast to frequently used unknown ambient excitation like wind. Information from part 1 will be transferred to a remote analysis centre using a module of wireless transmission of data. The part 2 installed directly on the bridge should record time responses of the structure induced by train passage. The time responses will be then transferred to the analysis centre (independently from part 1) using another module of wireless transmission. Having the information both about the dynamic load and the structural response to this load, monitoring of the bridge health can be performed by solving an inverse problem in the framework of the Virtual Distortion Method [2]. Deterioration of the bridge can be interpreted as stiffness degradation and/or mass loss for every element of the truss bridge. The undertaken in-situ monitoring campaign, started mid 2007, fits in the fast-developing research area called Structural Health Monitoring (SHM) [3]. The principal idea behind is that a structure should be subject to a permanent monitoring (performed not necessarily round the clock, but repeatedly). The main advantage of such monitoring is the ability to track changes in responses during the lifetime of a structure, raise alerts in case of significant deviations from normal behaviour and estimate the usable lifetime until demolition or general repair. The insitu monitoring system consists of two major components, depicted in Fig. 3, i.e. some sensors collecting responses in time and the central data processing unit (DP), providing basic signal processing and data transfer to a remote computational centre. The sensors may communicate with the DP unit either via cables or wirelessly. The latter way is the subject of consideration in this paper.
The goal of our investigations is to evaluate the photoacoustic spectroscopy technique a new tool for examination of technical working fluids properties. In the paper the last of spectrophotometric and photoacoustic measurements, concerning properties changes of oils and fuels after oxidation are presented. The photoacoustic experimental investigations of lubricating oils degradation in various conditions are outlined.
The paper presents the Adaptronica company experience in the field of the design, execution and testing of in-motion rail scales.The method of identification of loads applied in these scales is based on the measurement of rail deformations caused by passing trains.The results from experimental and simulation research on computerized railway scales are presented.The load identification algorithm and its practical implementation are shown.The implementation of the system, made on the basis of the device, is described.
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