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Abstract: An asphalt layer consists of stone aggregates, binder and air voids. The content of air voids (Vmin and Vmax), the voids filled with bitumen (VFBmin and VFBmax), the content of air voids in stone aggregates (VMAmin and VMAmax) and volume content of bitumen (VBmin) should be determined for each type of asphalt mixture. The volumetric properties of asphalt layer listed above are important parameters for assessing the properties of asphalt and are usually first presented in the requirements for produced asphalt mixtures and built in asphalt layers. Visualization of volumetric properties is important for understanding the composition of the produced asphalt mixture. The most appropriate is a triangular representation of the volumetric requirements for three main components of asphalt layer (stone, bitumen and air).
Keywords: volumetric representation, asphalt mixture, void content, voids in aggregate
Published in DiRROS: 22.02.2024; Views: 120; Downloads: 56
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Abstract: Tuber borchii forms ectomycorrhiza with oaks, hazel, and pines, including Pinus sylvestris. However, its ectomycorrhiza morphotype with P. sylvestris was not comprehensively described so far, and molecular analyses are missing despite a high danger of misidentification of T. borchii ectomycorrhiza with other closely related and less valuable truffle species. We described for the first time the morphology and anatomy of T. borchii-P. sylvestris ectomycorrhiza using differential interference contrast technique and semi-thin sections in combination with molecular confirmation of identity. Color of ectomycorrhiza is reddish to dark brown, and morphotypes are unevenly but densely covered by warts-bearing pin-like cystidia. All layers of the hyphal mantle are pseudoparenchymatous with outer mantle layer formed of epidermoid cells. T. borchii ectomycorrhiza was identified by a molecular comparison with fruitbodies used for inoculation and its respective ectomycorrhizae. T. borchii has a wide ecological amplitude. To get a better insight in mycorrhization requirements, we investigated growth of P. sylvestris and its ectomycorrhiza infection rate with T. borchii in substrate with different lime content. The mycorrhization of P. sylvestris with T. borchii in the mycorrhization substrate and cultivation in greenhouse conditions was successful, with colonization of P. sylvestris varying between 36.5 and 48.1%. There was no significant correlation of mycorrhization to applied lime contents, and consequently to pH in substrate, while the increased levels of lime improved growth of the P. sylvestris seedlings.
Keywords: root anatomy, ectomycorrhiza, Limestone content, molecular identification, Pinus sylvestris, Tuber borchii
Published in DiRROS: 22.01.2024; Views: 189; Downloads: 92
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Abstract: The importance of thermal modification is increasing worldwide. Increased use of thermally modified timber (TMT) has resulted in a need for reliable quality control, comprising control of variation of the production within defined limits, allowing third-party control in the case of certification and the regulation of customer complaints and claims. Techniques are thus needed to characterise the modification of quality in terms of improved target properties of TMT during industrial production, and of TMT products that have been in service for an arbitrary time. In this study, we aimed to utilise dynamic vapor sorption (DVS) for this purpose. Norway spruce (Picea abies) and European beech (Fagus sylvatica) samples were thermally modified at different temperatures according to different heat treatment techniques: (1) the Silvapro process based on an initial vacuum; (2) an air heat treatment, whereby samples were wrapped in aluminium foil; (3) thermal modification of wood samples in the ambient atmosphere in a laboratory oven. Wood samples from closed processes were analysed for validation. TMT was characterised with respect to mass loss, colour and density. Mass loss of wood due to modification (MLTM) was correlated with factors derived from DVS analysis. The present DVS measurements suggest that the equilibrium wood moisture content (EMC95% RH), the time to reach 10% wood moisture content (t10% MC), and the elongation factor, c, derived from a logarithmic function, can serve as alternative parameters to characterise the quality of several thermal modification processes. Further studies are recommended using other wood species, different modification processes and further parameters gained from DVS measurements to understand the robustness and the predictive power of the applied technique
Keywords: thermal modification, quality control, dynamic vapour sorption, wood, moisture content
Published in DiRROS: 31.08.2023; Views: 277; Downloads: 142
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Keywords: frost rings, sugar, sorbitol, phenolic content
Published in DiRROS: 13.09.2022; Views: 567; Downloads: 325
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Keywords: scald, gene expression, hydroxycinnamic acids, color, enzyme activity, phenol content, scald development, apples, cold storage
Published in DiRROS: 03.09.2020; Views: 1701; Downloads: 537
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