Cilj naše študije je bil razviti več različnih formulacij biokompozitnih in bionanokompozitnih filmov na osnovi polivinil alkohola (PVA) z dodatkom ojačitvene komponente – celuloznih nanofibril (CNF) ...in različnih tipov biološko aktivnih taninov – taninske kisline (TA), galne kisline (GA) in kostanjevega tanina (KT). CNF smo dodali v utežnem deležu 2 %; TA, GA in KT pa v utežnem deležu 4 % glede na PVA. S 4 % dodatkom TA v PVA matrico smo pripravili biokompozitni film, ki je izkazoval več kot 25 % višjo natezno trdnost v primerjavi z osnovnim PVA filmom. Z dodatkom 2 % CNF in 4 % TA v PVA matrico smo pridobili bionanokompozitni film (P2C4T) z izboljšanim modulom elastičnosti in natezno trdnostjo, hkrati pa smo z omenjenima dodatkoma povečali tudi fleksibilnost pripravljenega nanokompozita, saj je bila vrednost raztezka pri pretrgu za končni formulirani film (P2C4T) več kot 50 % višja od raztezka pri pretrgu za osnovni PVA film. Hidrofilnost površine dvokomponentnih PVA filmov je bila nižja, trikomponentnih pa višja.
While Slovenia has significant bioeconomy potential, it remains underutilized, facing challenges in primary bioeconomy sectors, their integration along value chains, uptake of industrial innovation, ...and institutional coordination. This paper aims to support the unlocking of Slovenia's bioeconomy potential, and foster sustainable and integrated development of its value chains. It provides the evidence base of the composition, volumes and current utilization of the available biomass streams from agriculture, forestry and aquatic systems. It discusses the potential uses of these resources and highlights the need for improved logistics and scalability. Additionally, the structure and performance of bioeconomy-related industries in Slovenia are examined, emphasizing the importance of firm consolidation and integration for successful bioeconomy development. It emphasizes the importance of sector-specific transformation pathways, from primary production to expanding hybrid sectors. The exchange between policymakers and stakeholders is encouraged to recognize synergies, accelerate cooperation, and improve economic performance while closing material and energy loops. The document also reviews the supporting environment for bioeconomy development and proposes steps for improved coordination and strategic planning.
The main objective of our study was to investigate the possible differences in the chemical composition of extractives from the bark of silver fir (
) with respect to the location of the bark sample ...on the tree, viz. differences in extract composition between stem bark and branch bark samples. Extractives in the bark samples from branches, depending on the distance of the sample from the trunk, were also analysed, and the stem bark samples were analysed with respect to their inner and outer parts. The results of the chemical analysis of extractives were supported by information about their antifungal and antioxidant effects. After felling and sampling silver fir trees, the collected bark samples were ground and freeze-dried. Extraction of bark samples was followed by a system of accelerated extraction using only water as a solvent. The extracts were analysed chemically using gravimetry, spectrophotometry and chromatography. Free-radical-scavenging activity was measured using the DPPH method, and the antifungal effect towards three moulds and three wood-decaying fungi was investigated with antifungal assay using the agar well diffusion method. It was found that the moisture content in bark samples decreased intensively just after the bark samples were peeled off the stem. Detailed chromatographic analysis showed that the bark extracts contained 14 compounds, among which phenolic acids, flavonoids and lignans were found to be the characteristic ones. The content of hydrophilic extractives in the branch bark samples decreased with increasing distance of the sample location from the tree stem. The largest amounts of phenolic extractives were measured in stem bark, followed by branch bark sampled at the point at which the branch entered the tree. Analysis of the separated parts of the bark showed that the outer layers of stem bark contained larger amounts of phenolic extractives, as well catechin and epicatechin, compared to the inner layers. Concentrated extracts of branch bark showed the largest free-radical-scavenging activity among the investigated samples, while strong antifungal effects of the bark extract were not found.
The content and composition of extractives in the wood and bark tissue of black locust (Robinia pseudoacacia L.) were investigated. Wood and bark samples were extracted using a Soxhlet apparatus with ...acetone. The extracts were gravimetrically examined to measure total hydrophilic extractive content. Total phenolic content was measured colorimetrically with a UV-Vis spectrophotometer. The wood and bark extracts were further investigated using high-pressure liquid chromatography (HPLC) to identify and quantify dihydrorobinetin in the extracts. The contents of total hydrophilic extractives, total phenols and dihydrorobinetin were higher in heartwood than in the sapwood and bark. No relationship was found between the height at which the samples were taken from the stem and the content of soluble components in the wood and bark. The heartwood of black locust represents a rich potential source of phenolic extractives.
In the case of Scots pine (Pinus sylvestris L.), anatomical differences between the sapwood and heartwood were researched, the content of extractives in the sapwood and heartwood defined, ...hygroscopicity of sapwood and heartwood studied, so as the relationship between the content of extractives and sorption properties. Research was carried out on 6 test trees. Anatomical investigations were performed using the classic light-field microscopy. Investigation of samples for determination of dimensional stability and sorption properties was held by conditioning in the glass-air condition chambers. Samples for chemical analysis were extracted with cyclohexane and a mixture of acetone and water, and the proportion of total phenols was determined by UV-Vis spectrophotometry. The differences between the sapwood and heartwood were in the resin canals, in the lumens of axial tracheids along the rays as well as differences in parenchymal cells and bordered pits. The content of extractives in the heartwood was higher than in the sapwood. Investigations of the sapwood and heartwood did not show statistically significant differences in the density in the absolutely dry state, at the point of saturation of cell walls, in the volume shrinkage, and not in the coefficient of swelling in the radial direction. We found differences between the sapwood and heartwood transverse anisotropy, differential swell in the tangential direction, in the coefficient of swelling in the radial direction and the sorption quotient. These differences can be attributed to mutual effect of the anatomical and chemical characteristics of both types of wood and when interpreting indicators of dimensional stability, the effect of the geometry of incremental layers should be taken into account.
At the end of 2020, Prof. Dr. Dr. h.c. Nikolaj Torelli became a Professor Emeritus of the University of Ljubljana. The title of Professor Emeritus is awarded to retired Professors for their ...significant contributions to the operation, reputation, and development of the University of Ljubljana. We briefly introduce our new Professor Emeritus and his work.
At the end of 2020, Prof. Dr. Dr. h.c. Nikolaj Torelli became a Professor Emeritus of the University of Ljubljana. The title of Professor Emeritus is awarded to retired Professors for their ...significant contributions to the operation, reputation, and development of the University of Ljubljana. We briefly introduce our new Professor Emeritus and his work.
Wood is a widely used material because it is environmentally sustainable, renewable and relatively inexpensive. Due to the hygroscopic nature of wood, its physical and mechanical properties as well ...as the susceptibility to fungal decay are strongly influenced by its moisture content, constantly changing in the course of everyday use. Therefore, the understanding of the water state (free or bound) and its distribution at different moisture contents is of great importance. In this study, changes of the water state and its distribution in a beech sample while drying from the green (fresh cut) to the absolutely dry state were monitored by 1D and 2D 1H NMR relaxometry as well as by spatial mapping of the relaxation times T1 and T2. The relaxometry results are consistent with the model of homogeneously emptying pores in the bioporous system with connected pores. This was also confirmed by the relaxation time mapping results which revealed the moisture transport in the course of drying from an axially oriented early- and latewood system to radial rays through which it evaporates from the branch. The results of this study confirmed that MRI is an efficient tool to study the pathways of water transport in wood in the course of drying and is capable of determining the state of water and its distribution in wood.
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