The structure of Tvrđa and its buildings date back to the Middle Ages. Tvrđa represents the Old Town of the city of Osijek and the best-preserved and largest ensemble of Baroque buildings in Croatia. After the withdrawal of the Ottomans in 1687, during the 18th century, the Austro-Hungarian administration systematically formed a new fortification system, regulated streets and squares and built a large number of military objects. Tvrđa took its present form in the 19th century and has kept it since then. Investigating the historical development of individual buildings, in addition to archival sources and existing architectural documentation, the obvious source of information are the buildings themselves. The aim of this paper is to explore the possibilities of using infrared thermography to find structural elements and hidden openings in historic buildings in Osijek's Tvrđa. This paper describes the exploration of the 18th century openings on the facades of the former Kostić houses. The facades were bricked into the walls in the 19th century because houses were reused and their purposes changed from commercial to residential. Infrared thermography is often a starting, nondestructive testing method (NDT) for building analyses. This paper presents thermographic analyses of two buildings. The analyses were carried out in December 2017 and January 2018. Using a steady-state thermographic analysis of a building envelope as the first step, the audit was continued with step heating (SH) of an interest point where changes in a thermal pattern were expected due to additional bricking. Heat flux was generated by the usage of a heat gun for paint removal.

In the modern power system, Flexible Alternating Current Transmission System (FACTS) devices are widely used. An increased share of the distributed generation (DG) and the development of microgrids change the power flows in the existing distribution networks as well as a conventional power flow direction from the transmission to the distribution network level which may affect the overall stability aspects. The paper shows the FACTS devices’ implementation influence on the performance of the distribution network with integrated renewable energy sources (RES) observing the aspects of the oscillatory stability and the low-voltage motor starting. The FACTS devices, in particular the static var compensators (SVC), have been allocated according to a novel algorithm proposed in the paper. The algorithm uses an iterative process to determine an optimal location for implementation and rating power of SVC considering active power losses minimization, improvement of the voltage profile and maximizing return of investment (ROI) of FACTS devices. Novel constraints—transformer station construction constraint, SVC industrial nominal power value constraint and the constraint of distribution system operator (DSO) economic willingness to investment in the distribution network development are considered in the proposed algorithm. The analysis has been performed on 20 kV rural distribution network model in DIgSILENT PowerFactory software.

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Infrared thermography as contactless method for determining the temperature distribution on the surface is used for analyzing the impact of intense pulsed light hair removal device (IPL) on the skin. Depth of light penetration depending of wavelength is described as well as absorption curves and IPL impulse shapes. Energy balance and IPL impulse influence on the skin is analyzed. Melanin temperature rise by different fluence operation and temperature distribution in the modeled hair is used in order to determine overall skin temperature rise. Estimated energy balance provided by mathematical model has been confirmed with experimental results. Performed measurements, beside determination of the right emissivity, required the identification of most significant parameter in the process which proved to be the skin reference temperature and real temperature rise. Practical IPL application with detailed body temperature analysis is comprehensively described and thermal imaging interpretation problem and determination of the temperature rise is observed.

Foam stability and retention is an important indicator of beer quality and freshness. A full, white head of foam with nicely distributed small bubbles of CO2 is appealing to the consumers and the crown of the production process. However, raw materials, production process, packaging, transportation, and storage have a big impact on foam stability, which marks foam stability monitoring during all these stages, from production to consumer, as very important. Beer foam stability is expressed as a change of foam height over a certain period. This research aimed to monitor the foam stability of lager beers using image analysis methods on two different types of recordings: RGB and depth videos. Sixteen different commercially available lager beers were subjected to analysis. The automated image analysis method based only on the analysis of RGB video images proved to be inapplicable in real conditions due to problems such as reflection of light through glass, autofocus, and beer lacing/clinging, which make it impossible to accurately detect the actual height of the foam. A solution to this problem, representing a unique contribution, was found by introducing the use of a 3D camera in estimating foam stability. According to the results, automated analysis of depth images obtained from a 3D camera proved to be a suitable, objective, repeatable, reliable, and sufficiently sensitive method for measuring foam stability of lager beers. The applied model proved to be suitable for predicting changes in foam retention of lager beers.

Circuit breakers (CBs) in the transmission network are the basic elements for energy flow control. CB diagnosis represents a decisive action for increasing power system reliability and safety. Their actual availability status and ability to perform major functions can sometimes be difficult to determine. This paper presents a general state estimation model based on fuzzy logic (FL), membership function (MF), and expert knowledge for diagnosis schemes to handle unclear information in the diagnosis procedure. The proposed model uses inputs from the Supervisory Control and Data Acquisition (SCADA) system, data on the position and state of the switch, changes in current in the network element CB (NECB), start or trip action of a protection relay on the NECB, and alarm status of the CB. For the diagnostic system input variables, data from the SCADA system, along with transformer and line protection devices, are used to allow the proper formation of rules and ultimately to determine the diagnostic status of the CB. The proposed method is tested on an authentic test power system, and the outcome results are compared with a previously reported technique. The obtained test results and the comparison prove the efficiency, authenticity, and fast operation feature of the suggested strategy.

Infrared thermography, in the analysis of photovoltaic (PV) power plants, is a mature technical discipline. In the event of a hailstorm that leaves the PV system without the support of the power grid (and a significant portion of the generation potential), thermography is the easiest way to determine the condition of the modules and revive the existing system with the available resources. This paper presents research conducted on a 30 kW part of a 420 kW PV power plant, and demonstrates the procedure for inspecting visually correct modules that have suffered from a major natural disaster. The severity of the disaster is shown by the fact that only 14% of the PV modules at the test site remained intact. Following the recommendations of the standard IEC TS 62446-3, a thermographic analysis was performed. The thermographic analysis was preceded by an analysis of the I-V curve, which was presented in detail using two characteristic modules as examples. I-V curve measurements are necessary to relate the measured values of the radiation and the measured contact temperature of the module to the thermal patterns. The analysis concluded that soiled modules must be cleaned, regardless of the degree of soiling. The test results clearly indicated defective module elements that would result in a safety violation if reused. The research shows that the validity criterion defined on the basis of the analysis of the reference module can be supplemented, but can also be replaced by a statistical analysis of several modules. The comparison between the thermographic analysis and the visual inspection clearly confirmed thermography as a complementary method for testing PV-s.

The aim of the study was to determine the effects of the parity and stage of lactation on tissue changes of the dairy cows' hooves (Holstein; n = 130) and their early detection using the thermovision camera. The parity did not have a significant impact on temperature of the coronary band (CB) for the cows with lesions, although the stage of lactation did (P<0.0001) between first and second parity. For the cows without lesions the parity and stage of lactation had a significant (P<0.01; P<0.0001) influence on the temperature of the CB. The obtained results indicate that stage of lactation has a stronger influence on temperature of coronary band than parity. This knowledge is crucial when using thermovision cameras for detection of the cows which are at risk of lameness.