In the last decade, there have been many reports on the negative impact of wildfires on various ecosystems. Unfortunately, wildfires have been intensifying as global temperatures, droughts, and other instances of extreme weather events rise around the world. These circumstances are forcing communities to vigorously address the uncontrolled spread of wildfires, where the ultimate goal is the protection of wildlife. At the same time, many disaster prevention and monitoring methods, based on image processing and computer vision, have been developed. In this paper, we present a new unsupervised method based on RGB color space for the early detection of wildfires from still images. From the analysis of existing state-of-the-art methods, it is evident that different methods explore different color spaces for the extraction of flame features. Our motivation was to use only RGB color space and thus eliminate the time-consuming task of color space conversion. The proposed method consists of several new image processing techniques used to efficiently extract flame features. It outperforms the existing methods, where an increase of 3% and 2% is recorded in the F1 score and Matthews correlation coefficient, respectively. Such performance demonstrates the merits of the proposed method for flame segmentation and detection.

Introduction. The aim of this study was to evaluate the influence of the carbomer concentration (used as the gelling agent, in the range 0.5 - 2.0%) on textural and sensory characteristics of gels with 3% panthenol using sensory analysis as subjective and texture analysis as an objective assessment method. An active substance in the gels was panthenol, which also acted as a neutralizing agent of the carbomer. Participants and methods. Twenty female panelists, aged between 20 and 36, participated in the sensory study and had to fulfill a questionnaire regarding product attributes before, during and after application on the skin. Texture analysis was performed on CT3 Texture Analyzer, after each week for a month, and the following parameters were calculated: hardness cycle 1, hardness cycle 2, cohesiveness, adhesiveness, resilience and springiness. Results. The results showed that gels were stable over time and the structure of the gels was preserved regardless of compression. An increase in hardness and resilience was followed by an increase in the concentration of carbomer, while adhesiveness, cohesiveness and springiness did not differ much among different gels. The same trend was noticed when gels were compared during time. Sensory analysis confirmed findings of texture analysis and showed that with the increment of carbomer concentration, stickiness and density also enhanced, while absorption rate and spreadability decreased. Gel with 1% carbomer was chosen by the majority of panelists as favorite and as a gel they would regularly use. Conclusion. The methods of textural and sensory analysis represent valuable approaches in drug/cosmetic product design because they offer insight in the compliance of patients/consumers.

Introduction/purpose: The paper presents interesting research related to the performance analysis of the picture-wise just noticeable difference (JND) prediction model and its application in the quality assessment of images with JPEG compression. Methods: The performance analysis of the JND model was conducted in an indirect way by using the publicly available results of subject-rated image datasets with the separation of images into two classes (above and below the threshold of visible differences). In the performance analysis of the JND prediction model and image quality assessment, five image datasets were used, four of which come from the visible wavelength range, and one dataset is intended for remote sensing and surveillance with images from the infrared part of the electromagnetic spectrum. Results: The pap 86 er shows that using a picture-wise JND model, subjective image quality assessment scores can be estimated with better accuracy, leading to significant performance improvements of the traditional peak signal-to-noise ratio (PSNR). The gain achieved by introducing the picture-wise JND model in the objective assessment depends on the chosen dataset and the results of the initial simple to compute PSNR measure, and it was obtained on all five datasets. The mean linear correlation coefficient (for five datasets) between subjective and PSNR objective quality estimates increased from 74% (traditional PSNR) to 90% (picture-wise JND PSNR). Conclusion: Further improvement of the JND-based objective measure can be obtained by improving the picture-wise model of JND prediction.

Introduction/purpose: The article presents a model of a slow frequency hopping radio in the case of repeater jamming. The aim is to analyze the effectiveness of repeater jamming to a military tactical slow frequency hopping radio. Methods: It is assumed that the repeater jammer will be successful in detecting signals with slow frequency hopping at each hop and that it will perform successful partial jamming of the intercepted communication. Under partial jamming, it is considered that a certain part of the transmission time of each hop will be jammed. A theoretical analysis of the impact of a repeater jammer on a frequency hopping radio was performed based on the definition of the total probability of error. Various parameters that affect the segment of hop duration under jamming were considered. Results: The obtained results show that high effective jamming is achieved even when a short segment of hop duration is jammed. We discuss the conditions for the repeater jammer to detect the signal during each hop and emit the jamming signal with the required strength. It has been shown that increasing the frequency hopping rate can significantly reduce the effectiveness of the repeater jammer. Conclusion: Repeater jammers are highly effective against slow frequency hopping radio communication systems.

Tourism is very important for the development of the country. In order to develop, every country must invest in tourism and use its resources to attract tourists. This research took into account how natural and cultural resources influence the improvement of tourism performance. On that occasion, it was observed what influence the rate of economic growth has on the relationship between natural and cultural resources and the performance of tourism. Therefore, regression analysis was used with the mediator gross social product, which represents economic growth. The results showed that three out of four tourism performances are influenced by natural and cultural resources when changing the rate of economic growth. In this way, it has been proven that natural and cultural resources influence the performance of tourism. That is why tourism must be based on the natural and cultural resources available to the country. It is necessary to invest in infrastructure, especially in road infrastructure, in order to make these resources more accessible to tourists.

Unlike most military high explosives, which are characterized by an almost plane detonation front, ammonium nitratebased commercial explosives, such as ANFO (ammonium nitrate/fuel oil mixture) and emulsion explosives, are characterized by a curved detonation front. The curvature is directly related to the rate of radial expansion of detonation products in the detonation driving zone and the rate of chemical reactions, and it is one of the characteristics of nonideal explosives. The detonation theories used to model the nonideal behaviour of explosives require both reaction rate and rate of radial expansion to be known/specified as input data. Unfortunately, neither can be measured and what is mostly used is a link between these rates and parameters which can be more easily measured. In this paper, the Wood-Kirkwood approach of determination of radial expansion through the radius of detonation front curvature and the electro-optical technique for experimental determination of detonation front curvature of ANFO explosives is applied. It was shown that an experimentally determined radius of detonation front curvature vs charge diameter, incorporated in the Wood-Kirkwood detonation theory, can satisfactorily reproduce experimental detonation velocity-charge diameter data for ANFO explosives, especially when the pressure-based reaction rate law is also calibrated (D=1.3 and k=0.06 1/(μs/GPaD)).

Deep eutectic solvents (DESs) are called 'designer solvents' due to various structural variations and the benefit of tailoring their physicochemical properties. For industrial applications of DESs it is crucial to know their physical and thermodynamic properties such as density, viscosity, and refractive index. These properties were measured for three lecithin (LEC)-based DESs with glycerol (G), triethanolamine (TEOA), and oleic acid (OLA) as functions of temperature. The viscosity was fitted by both Arrhenius-type and Vogel-Tamman-Fulcher equations. The density, viscosity, and refractive index of tested DESs decreased with the increase in temperature. The LEC:G DES exhibited the lowest density at all tested temperatures. This DES was selected as a cosolvent in the ethanolysis of cold-pressed black mustard (Brassica nigra L.) seed oil catalyzed by either calcined or non-calcined CaO. The reaction was carried out in a batch stirred reactor under the following conditions: the temperature of 70?C, the ethanol-to-oil molar ratio of 12:1, and the amount of DES and CaO of 20 and 10 wt.% (to oil), respectively. The presence of DES accelerated the reaction, while the separation of the final reaction mixture phases was faster.