In the constant pursue of the sustainability of socio-industrial systems, the definition of useful, reliable and informative, and at the same time simple and transparent, indicators is an important step for the evaluation of the circularity of the assessed systems. In the circular economy (CE) context, scientific literature has already identified the lack of overarching indicators (social, urban, prevention-oriented, etc.), pointing out that mono-dimensional indicators are not able to grasp the complexity of the systemic, closed-loop, feedback features of CE. In this respect, Emergy accounting is one of the approaches that have been identified as holding the potential to capture both resource generation and product delivery dimensions and therefore to provide an enhanced systems’ evaluation in a CE perspective.

Because of Emergy’s intrinsic definition and its calculation structure, Emergy-based indicators conceptually lend themselves very well to the evaluation and monitoring of circular processes. Additionally, Emergy has the unique feature of enabling the evaluation of systems that are not necessarily only technosphere systems, but also of technological systems which embed nature (techno-ecological systems).

The present paper gives a perspective on a set of Emergy-based indicators that we have identified as suitable to evaluate circular systems, and outlines the different perspective compared to the circularity indicators defined in the “Circularity Indicators Project” launched by the Ellen MacArthur Foundation.

Today, ensuring energy security is becoming increasingly important. It has been proven that agricultural crops are currently the dominant feedstock for the production of biofuels and first-generation biofuels dominate both in Ukraine and around the world and can potentially pose a threat to food security. The research aims to analyze the state of food security in Ukraine in order to estimate the economic basis for the use of surplus food crops for biofuel production for substantiating the required areas for growing energy crops in the volumes that could ensure balance between the food and energy use of crops. An analysis of food security of Ukraine showed that the agricultural sector provides the population with most of the necessary food products, but it is advisable to modernize the food supply standards. It has been proven that crops that can be used for the production of first-generation biofuels in Ukraine are produced in sufficient quantities to ensure food security, and they are exported without compromising the food security of the state and export potential.
As calculated, Ukraine can use about 11–12 million hectares of arable land for growing energy crops with their subsequent processing into biofuels. It has been proven that in the future in Ukraine, it is recommended to develop the production of biofuels (biogas and solid biofuels) from crop and livestock waste, as well as organic waste from processing enterprises. This would not pose a threat to food security and would address a number of environmental issues related to waste disposal. Today, under the condition of war in Ukraine, food security and energy independence are priority issues and energy diversity, including the production and consumption of biofuels, is a top factor for further development.

The article discusses results of pull-off adhesion strength tests on poly-p- phenylene benzobisoxazole (PBO) mesh bonded to fir timber beams using epoxy resin. The tests were performed in accordance with the PN-EN 1542 standard. Timber elements reinforced with PBO fibres were subjected to pull-off tests to measure the adhesive strength of the mesh to the beams.The factors occurring during the test were also characterized, which may affect its results such as the method of application of the tearing force, selection of epoxy glue, surface preparation of the tested elements, occurrence of material defects in the wood and types of substrate destruction.The experimental data show that failure of the timber layer was not observed in all the specimens tested.

The objective of this work is to demonstrate for the first time the results of hydrogeochmical studies carried out in the Steinvik River catchment, in order to provide detailed information regarding the chemical composition of groundwater in the Hornsund region, SW Spitsbergen. The water chemistry in the non-glaciated Steinvik River catchment is largely controlled by hydrological processes related to thaw of the near surface permafrost. Groundwater runoff is generated from the fast flow through well-permeable active layer. Recharge from melting snow, permafrost and rain, together with short residence time of groundwater, favors the forming of low-mineralized water, reaching 41 and 50 μS/cm for surface and groundwater, respectively, with the dominance of HCO3−, Cl−, Mg2+, Ca2+ and Na+ ions. In some water samples, increased concentrations of aluminum (up to 268 μg/L ) were found. The highest concentrations of phosphate, nitrite and ammonium in water seem to be related to the presence of bird colonies. Groundwater of active layer in the studied catchment belongs to young meteoric water with the age limited to one summer season.