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The subject of the research conducted by differential scanning calorimetry (DSC) was hydrated mixtures of polyethylene glycol and gentamicin (GEN) in a 1:1 (w/w) ratio. In this way, a system with a particularly high ability to form hydrogen bonds was created. It was postulated that studying the effective activation energy (EA) of the thawing process of diverse hydrated polymer mixtures will indirectly allow for an attempt to assess the distribution of water molecules in the examined material in future studies. This article presents a detailed analysis of the impact of selected parameters on the calculation of EA using the Belichmaer and Duswalt methods. The research focused on assessing how the interpolation method affects the accuracy of results obtained from these techniques. The interpolation method was analyzed in terms of its ability to accurately replicate experimental data. By evaluating the impact of the number of points from the DSC curve used in linear interpolation, a standard deviation from the average value of EA was obtained, respectively: 2.4% for the Belichmaer method and 1.9% for the Duswalt method. The article also shows that by using both methods simultaneously, it is possible to detect the moment when additional endothermic and exothermic reaction activity becomes present in the reaction curve. This allowed for the avoidance of the depletion error. Computer modeling and simulations were used to compare the effectiveness of both techniques in various scenarios. The results showed that the choice of interpolation method and taking into account the depletion error significantly affect the accuracy of calculating EA. The computed activation energy via Duswalt method was EA = 363.32 kJ mol−1 with a standard deviation of 7.07 kJ mol−1 and using the Belichmaer method the EA was 364.81 kJ mol−1, with a standard deviation of 9.10 kJ mol−1. [ABSTRACT FROM AUTHOR]

This paper discusses the pull-out laboratory tests and the monitoring of expansion-shell bolts with a length of 1.82 m. The bolts comprised the KE-3W expansion shell, a rod with a diameter of 0.0183 m and a profiled, circular plate with a diameter of 0.14 m, and a gauge of 0.006 m. The bolts were installed in a concrete block with a compressive strength of 75 MPa. The tests were conducted on a state-of-the-art test stand owned by the Department of Underground Mining of the AGH University of Science and Technology. The test stand can be used to test roof bolts on a geometric scale of 1:1 under static and rapidly varying loads. Also, the stand is suitable for testing rods measuring 5.5 m in length. The stand has a special feature of providing the ongoing monitoring of bolt load, displacement and deformation. The primary aim of the study was to compare the results recorded by two different measurement systems with the innovative Self-Excited Acoustic System (SAS) for measuring stress variations in roof bolts. In order to use the SAS, a special handle equipped with an accelerometer and exciter mounted to the nut or the upset end of the rod was designed at the Faculties of Mining and Geoengineering and Mechanical Engineering and Robotics of the AGH University of Science and Technology. The SAS can be used for nondestructive evaluation of performance of bolts around mining workings and in tunnels. Through laboratory calibration tests, roof bolt loads can be assessed using the in-situ non-destructive method.

The use of augmented reality glasses is one of many elements of the standard known as Industry 4.0. This article shows the use of Microsoft HoloLens headset to support the work of the semi-automatic machine operator. As the quality of collecting cloud points for these glasses is not enough, it was decided to implement a neural algorithm that was used to filter the online image obtained from augmented reality headset.

This article presents a new algorithm for recognizing defects and discontinuities. It is a neural classification algorithm of the SVM class used for the vision system in the technological sequence. At the basis of the used method of Support Vector Machines (SVM) lies the concept of decision-making space, which is divided by building boundaries separating objects with different class affiliation, that is, defects and discontinuities. The Support Vector Machines method is supposed to perform classification tasks by constructing in a multidimensional space hyperplane separating cases belonging to different classes.

A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units – quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics) are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

In the paper two types of numerical models of the self-excited acoustical system are presented. This new type of auto-oscillating system is used for stress change measurement in constructions and rock masses. The essence of the self-excited acoustical system is to use a vibration emitter and vibration receiver placed at a distance, which are coupled with a proper power amplifier, and which are operating in a closed loop with a positive feedback. This causes the excitation of the system. The change of the velocity of wave propagation, which is associated with the change of the resonance frequency in the system is caused by the deformation of the examined material. Stress changes manifest themselves in small but detectable variations of frequency. The first of the presented models was created on the basis of estimating the model parameters by identification of the sensor–conditioner–amplifier–emitter system. The second mathematical model was delivered from the force–charge equation of the piezoelectric transducers: the sensor and the emitter. The model of the loaded beam, which determined the response of any beam point to the force applied to any other beam point is also presented. [ABSTRACT FROM AUTHOR]

Within the article the applicability of the Self-oscillating Acoustical System (SAS) in order to continuously monitor changes in strain was examined. The essence of SAS is to use a vibration exciter and vibration receiver placed in a distance, which is coupled by an amplifier operating in a positive feedback loop. Changing the speed of wave propagation, which is associated with the change of frequency in the system, can be measure of deformation of the material. The study confirmed the existence of the phenomenon of self-oscillating which can be used to assess the state of metal frame deformation. [ABSTRACT FROM AUTHOR]