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This study investigated peoples requirements for multi-story housing attributes and preferences for apartments in wooden-structure versus steel/concrete-structure multi-story buildings. Data came from an online survey conducted in Finland and Sweden that screened for respondents who expressed a preference for living in an apartment, as compared with a low-rise dwelling. Responses were analyzed using exploratory factor and regression analyses. Swedish respondents assigned significantly higher requirements to factors related to environmental and social sustainability performance than Finnish respondents. Requirements in both countries were described across three factors: environmental and social sustainability, quality, and design. Factor scores differed between socioeconomic sub-groups, particularly regarding quality, between urban and non-urban respondents. Preferences to live in an apartment in a wooden building were positively associated with respondents requirements for environmental and social sustainability, and negatively with requirements for quality-related attributes. Opposite relationships were found in the Swedish sample for apartments in non-wooden structure houses. Design requirements had no significant association with preferences for a specific material in load-bearing structures for multi-story buildings, in either country. The findings can contribute toward enhanced marketing efforts and customized value propositions to increase the social acceptability of multi-story wooden buildings and advance climate-related goals within the housing sector. Funding Agencies|Swedish government research council for sustainable development (FORMAS) [Brg1928]; Nordic Forest Research

Funding Information: The authors are grateful for Niemi foundation for research grants ID 64930 and ID 64990 for 2020 and 2021, respectively, that financed this work. We also thank The Slovenian Research Agency within the framework of research programs P4-0015 and P4-0121 for making some of the research equipment available to us. The authors would like to acknowledge Senior Scientist Panu Lahtinen from VTT Technical Research Centre of Finland Ltd for helping with the pulp microfluidization trials, and Senior Scientist Jani Seitsonen deserves special thanks for their help with the TEM and WAXS measurements. Funding Information: The authors are grateful for Niemi foundation for research grants ID 64930 and ID 64990 for 2020 and 2021, respectively, that financed this work. We also thank The Slovenian Research Agency within the framework of research programs P4-0015 and P4-0121 for making some of the research equipment available to us. The authors would like to acknowledge Senior Scientist Panu Lahtinen from VTT Technical Research Centre of Finland Ltd for helping with the pulp microfluidization trials, and Senior Scientist Jani Seitsonen deserves special thanks for their help with the TEM and WAXS measurements. Publisher Copyright: © 2022, The Author(s), under exclusive licence to Springer Nature B.V. A hardwood dissolving pulp and bleached softwood Kraft pulp were subjected to continuous ultrasonic cavitation assisted TEMPO-mediated oxidation. The effects of such processing on the yield of carboxylic groups, morphological changes of the fibers as well as the effects on the final nanocellulose dispersion were studied. Ultrasonic cavitation in the TEMPO-mediated oxidation phase enhanced the yield of carboxylic groups on both pulps while having a negligible effect on materials losses due to fiber fines formation. The effect of ultrasonic cavitation was purely mechanical and acted as an additional high-shear mixer in the pre-treatment phase. As a result, the morphological changes on the fibers were enhanced, with additional swelling and fiber straightening being observed. Furthermore, the ultrasonic cavitation also influenced the properties of the nanocellulose dispersion obtained from subsequent microfluidization. The sonicated samples exhibited higher optical clarity, higher elasticity in gels while also having somewhat lower viscosities. On nanoscale, ultrasonic cavitation helped the subsequent microfluidization in releasing better individualized nanofibrils as they had smaller diameters than in non-sonicated samples. Sonication also had no effect on the crystallinity properties of the nanocellulose, the observed slight reduction was a result of intense microfluidization that was used to produce the nanocellulose dispersion. Ultrasonic cavitation in the TEMPO-oxidized pre-treatment phase was shown to be a method that can increase the throughput in lab-scale by mechanical activation of pulps and enabling shorter processing times for TEMPO-mediated oxidation. Graphical abstract: [Figure not available: see fulltext.].

Freshwater habitats and species have been lost because of river constructions, particularly regarding hydropower plants. Such losses may be mitigated, for example, by providing compensatory habi tats. We present a case which had the objective to promote reproduction of a key species. Imatra City Brook in Finland was constructed in 2014 at a hydropower dam as a new reproduction area for brown trout (Salmo trutta L.). In the planning phase, the objective was to maximize suitable habitat types and areas with limited discharge. Monitoring shows promising densities of brown trout juve niles within only three years, inspiring hope for high smolt production in the main river. The increase in total macroinvertebrate abundances and taxa numbers in the second year of monitoring showed that species richness was comparable to that in natural rivers, and the brook was in a good eco logical state. This case confirms the expected high potential of spawning and rearing channels to improve migratory fish stocks and compensate for lost habitats in constructed rivers.

Purpose Norway spruce log soaking water (SLSW) is considered a waste in the plywood and veneer industry but has not been characterised, and its possible uses remain unexplored. The purpose of this study is to characterise and test the possibility of using SLSW in wood preservative formulations. Methods First, the SLSW was characterised, and the presence of carbohydrates in the log soaking water was reduced with a hydrophobic adsorbent to reduce the nutrient availability for fungi in the liquids. Then, the feasibility of using SLSW and the sugar free SLSW (denoted later as EHC solution) as wood preservatives was studied by testing their antifungal and antioxidant activities and performing a mini-block test against Schizophyllum commune, Trametes versicolor, Fibroporia vaillantii and Gloeophyllum trabeum. Results Several phenolic compounds were found in the SLSW. This water also had high antioxidant activity at 1000 mg/L before and after carbohydrate removal but no antifungal activity. Its impregnation in wood caused a slight reduction in mass loss of the Pinus sylvestris specimens but had no effect on the Fagus sylvatica specimens when exposed against Schizophyllum commune, Trametes versicolor, Fibroporia vaillantii and Gloeophyllum trabeum. Conclusion The SLSW as a wood preservative is invalid, even after partial carbohydrate removal. However, due to the presence of wood constituents, SLSW could be a resource for other uses requiring high antioxidant activity but specific applications need further investigation. Graphical Abstract

The tree bark represents an abundant but currently underutilized forest biomass side stream. In this work, temperature-programmed slow pyrolysis with fractional condensation was used for thermochemical conversion of the bark obtained from three short rotation tree species, aspen, goat willow, and rowan. Heating was performed in three stages, drying (135 °C), torrefaction (275 °C), and pyrolysis (350 °C), and the resulting vapors were condensed at 120, 70, and 5 °C, producing nine liquid fractions. An additional fraction was collected in the pyrolysis stage at 0 °C. The obtained liquid fractions were characterized in terms of their yields and bulk chemistry (i.e., CHNOS content, water content, pH, and total acid number) as well as their molecular level chemistry by high-resolution mass spectrometry. The highest liquid yields were obtained for the fractions condensed at 70 °C. The water content varied considerably, being the highest for the drying fractions (>96%) and the lowest for the pyrolysis fractions obtained at 120 °C (0.1-2%). Considerable compositional differences were observed between the liquid fractions. While the drying fractions contained mostly some dissolved phenolics, the torrefaction fractions contained more sugaric compounds. In contrast, the pyrolysis fractions were enriched lipids (e.g., suberinic fatty acids and their derivatives) and alicyclic/aromatic hydrocarbons. These fractions could be further refined into different platforms and/or specialty chemicals. Thus, slow pyrolysis with fractional condensation offers a potential route for the valorization of tree bark residues from forest industry.

High-definition automated optical analysis was used to observe the morphological changes of bleached hardwood dissolving pulp during oxidation mediated by (2,2,6,6-tetramethylpiperidn-1-yl)oxyl (TE...

In this study a commercial particle analyzer was used to image and help sorting microplastic particles (MPs) dispersed in filtrated and de-aerated tap water. The device provides a relatively easy and fast procedure for obtaining ultra-high-definition imaging, allowing the determination of shape, size, and number of 2D-projections of solid particles. The image analysis revealed clear differences among the studied different MPs originating from the grinding of five common grades of plastic sheets as they affect the image rendering differently, principally due to the light scattering either at the surface or in the volume of the microplastics. The high-quality imaging of the device also allows the discrimination of the microplastics from air bubbles with well-defined spherical shapes as well as to obtain an estimate of the size of MPs in a snapshot. We associate the differences among the shapes of the identified MPs in this study depending on the plastic type with known physical properties, such as brittleness, crystallinity, or softness. Furthermore, as a novel method we exploit a parameter based on the light intensity map from moving particles in cuvette flow to sort MPs from other particles, such as, wood fiber, human hair, and air bubbles. Using the light intensity map, which is related to the plastic-water refractive index ratio, the presence of microplastics in water can be revealed among other particles, but not their specific plastic type.

The behaviour of industrially modified wood has not been systematically evaluated in controlled exposure conditions. The objective of this study was to assess the equilibrium moisture content (EMC), dimensions, and Brinell hardness of thermally modified wood in different conditions of temperature and relative humidity (RH). Tested materials consisted of European ash (Fraxinus excelsior L.), Norway spruce (Picea abies (L.) Karst.), and Scots pine (Pinus sylvestris L.) that were thermally modified according to ThermoWood industrial processes into the classes Thermo-S and Thermo-D. The properties were measured at the following conditions: 20 °C and 65% RH, 10 °C and 90% RH, and 30 °C and 30% RH. The results show that the reduction of EMC and the improvement in dimensional stability are dependent on the degree of thermal modification. Thermal modification was more resistant to moisture absorption at 20 °C and 65% RH than at 10 °C and 90% RH and 30 °C and 30% RH, and the more severe modification decreased the difference among different exposure conditions. The tangential–radial ratio of swelling and shrinkage was higher for thermally modified wood than for nonmodified wood. Brinell hardness of modified Scots pine and Norway spruce did not differ significantly from that of nonmodified wood in normal and dry conditions, but the more humid conditions increased the difference by 12%–17%.

Evolving complex concepts, such as bioeconomy, cannot be applied without selecting (consciously or unconsciously) some definitions and excluding others. This process of selection may have a considerable impact on how bioeconomy is understood. This paper presents how the concept of bioeconomy took shape in a participatory development project that created foundations for new professional specialisation studies within the Finnish bioeconomy. Written documents (n = 21), produced in different phases of the project, were analysed with qualitative content analysis to find out how bioeconomy was A) understood as an activity, and B) conceptually linked with different global meta-discourses. Bioeconomy was primarily understood as an intensive use of diverse biomasses within a forest cluster, agriculture, the food industry, waste management and the energy sector, whereas many other bioeconomy sectors were marginalised or excluded. The idea that biomasses should be saved was very rare, and the concepts that prioritise some biomass uses over others, such as the cascade principle, were excluded. Bioeconomy itself was understood as a societally and globally influential new way of thinking i.e. as a meta-discourse. Strong associations were also made to nationalistic and statist meta-discourses. Conceptual transformation during the project was most distinct in the sustainable development meta-discourse: sustainability turned from a self-evident characteristic of bioeconomy into a consciously reflected and desirable goal. The results illustrate how a common consensus of bioeconomy is built through exclusion and inclusion in a participatory development project. Project organisers should be conscious about this process and explicitly state how and why some aspects, actors and activities are emphasised while others are downplayed or excluded in their bioeconomy projects. Only then we can create far-reaching policies and considered actions to guide societies toward the desired and defined future.

The quest for cleaner wood preservatives is one of the major foci of contemporary wood science. Pyrolysis distillates are potential intermediates to extract large volumes of bioactive chemicals. The aim of this study was to characterize pyrolysis distillates from spruce and birch bark and hemp and test different fractions as potential antifungals to prevent wood decay. In all the fungi tested, distillates of spruce caused over 40% inhibition at 0.1% concentration; significant inhibition could be observed when the concentration of the distillates in growth media was 1%. The results indicate that inhibition was caused by the synergetic action of different chemicals in the pyrolysis distillates. When the individual components were considered, propionic acid exhibited a very high inhibitory effect against the wood decay fungi. The high inhibition of the pyrolysis distillates at 1% and lower concentrations demonstrate that pyrolysis liquids could be a source for formulations of sustainable wood preservatives.

Companies in the wood industry are constantly developing their outdoor products. The possibility of using bio-based chemicals as an alternative to traditional wood preservatives-regulated in Europe by The Biocidal Products Regulation No 528/2012-has been considered, but chemical leaching from the wood decreases its effectiveness and may negatively affect the environment. This study aims to compare the effectiveness of bio-based chemicals with potential use in wood preservation to commercially available preservatives, to investigate their fixation to wood and their ecotoxicity and to quantify the potentially toxic elements leached from the wood. Pyrolysis distillates of tree bark, organic acids found in distillates, Colatan GT10 tannin extract and log soaking liquid as a hardwood veneer process residue were tested and compared with commercial pine oil and a copper-based wood preservative. In the wood decay test of impregnated pine sapwood specimens, Colatan GT10 extract performed as well as the commercial wood preservatives. The same decay trial with leached specimens significantly reduced the performance of the bio-based chemicals. The results of the ecotoxicity test with photoluminescent Aliivibrio fischeri bacteria showed that many bio-based chemicals with potential use in wood preservation have markedly lower ecotoxicity than commercially available wood preservatives, but the ecotoxicity of some bio-based chemicals is higher, as in the case of some of the pyrolysis distillates. The wood preservation efficiency and the ecotoxicity of the studied chemicals had a poor correlation, implying that other factors besides treatment agent toxicity play a role in deterring fungal growth on treated wood. The amount of elemental toxins in the leachates was low. These results emphasize the importance of the chemical ecotoxicity of bio-based preservative compounds, as their detrimental effect on the environment can be higher than that of the traditional preservatives unless effectively linked to wood to prevent leaching.

Thermally modified wood (TMW) is widely used in outdoor applications due to its advanced properties towards weathering stresses. Although the structure changes of TMW from weather factors have been reported, investigation of the quantitative analysis of water states and cell wall structure of TMW after weathering is limited. In this work, the amount of bound water, fiber saturation point (FSP), cell wall pores, and free water distribution of thermally modified Scots pine, Norway spruce, and European ash were measured before and after a 2-year natural weathering via NMR relaxometry, cryoporometry, and magnetic resonance imaging. The results show that weathering increased T2 relaxation time of lumens, indicating the degradation of tracheids and vessels, especially in TMW compared to unmodified wood. The amounts of bound water, FSP value, and cell wall pores were increased after weathering; however, an increase in thermal modification intensity resulted in lower FSP and limited the increase in number of pores. In summary, TMW showed better performance than unmodified wood after weathering.

We demonstrate that direct imaging is a powerful tool for the detection and recognition of microplastics in water, even in case of complex matrices. We use a commercial high-resolution imaging device (Valmet FS5, Valmet Oy.) originally developed for the observation of wood fibres and particles in papermill pulp samples. We show how to discriminate microplastics from other particles in suspension in real water samples. We show differences between several common plastic types in homemade samples.

Microbial growth on culture media is a commonplace technique to estimate the growth rate and virulence of microbes, assess inhibitory effects of compounds and estimate potential damages of plant pathogens in agriculture. Growth area measurement of solid cultures is still commonly performed as a manual process that requires skilled technicians and substantial time, thus warranting an automated system to reduce the workload and increase measurement efficiency. A machine learning approach (Support Vector Machines) was developed to fully automate the area measurement process. We developed a functional model that processes images and returns the microbial area coverage considerably faster than a manual measurement method, with minimal user input and highly comparable results (R2 = 0.88, kappa = 0.88) applicable over large datasets.

Fungi and microbes can remarkably degrade the appearance and durability of organic materials, such as wood. The inhibitory effects of natural phenolics may offer more sustainable alternatives to preserve wood than the toxic biocides that are currently used. Although pure caffeine has been proven to have antibacterial properties, the applicability of spent coffee in wood preservation has not been determined. This work conducted in vitro tests with three brown rot and one white rot fungi and demonstrated the potential of spent coffee-derived cinnamates, analyzed with high-performance liquid chromatography, as antimicrobial agents. Spent coffee at concentrations of 1% and above in the growing media caused significant growth suppression of all of the fungi. This was not only because of the caffeine, but also the other chemicals present in the residue extracts, which demonstrated that spent coffee could be used as a source of green chemicals in wood preservative formulations.

New energy crops adapted to northern conditions of Europe can broaden the portfolio of agricultural based biofuel options in an area with currently few alternatives. This study evaluates two energy crops, giant knotweed (Fallopia sachalinensis var. ‘Igniscum’) and Virginia mallow (Sida hermaphrodita), as possible biomass feedstocks for biofuels in southern Finland. The collected data includes yield productivity, physical and chemical properties, and energy content. The dry matter yield of giant knotweed ranges from 5.41 odt·ha−1 to 27.67 odt·ha−1, whereas Virginia mallow ranges from 6.72 odt·ha−1 to 16.72 odt·ha−1. Pellets from both crops meet the requirements regarding standards. Giant knotweed presents a bulk density of 677.71 kg·m−3 and Virginia mallow 725.18 kg·m−3. The results of mechanical durability of giant knotweed do not exceed the minimum threshold of the standards, with 96.73 w-%, while Virginia mallow is 92.86 w-%. The analysis of the ash content results in 1.5% for giant knotweed and 2.19% for Virginia mallow. The quantities of chlorine (Cl) and sulphur (S) are below the recommended thresholds. Finally, the energy content with moisture content of 5 w-% of giant knotweed and Virginia mallow were 19.97 MJ·kg−1 and 19.68 MJ·kg−1, respectively. Both crops prove are valid alternatives in the climatic and soil conditions of Northern Europe.

Wood biomass for energy can be largely produced in northern Europe from forest land resulting from silvicultural practices and from agricultural land in the form of fast-growing plantations. The present paper estimates and compares the current regional potentials for wood biomass production attending to these sources. The data are based on spatialized estimates from previous models, largely based on empirical records concerning forest and plantation's productivity. The results show that 8.5 Mm 3 of wood biomass can be produced annually from plantations when using 5% of the total available agricultural land, and 58.5 Mm 3 from forest lands using current estimates of forest production. However, the results also show that a strategy for wood biomass resource management should be local rather than general: wood biomass potential from fast-growing plantations was larger in 19 regions than from forest resources (10 in Denmark, 6 in Norway and 3 in Lithuania) out of the 91 regions in the area included to this study. When considered together, northern Europe presents significant potential for wood biomass production for energy uses, and each country - and even region - should develop independent policy strategies of biomass generation in order to most efficiently realize their own potential for wood-based bioenergy.

The presented work deals with hygro-thermal numerical simulation and mould growth risk evaluation between concrete foundation and frame of multi-story building made of CLT element modules. Structural CLT modules represent an approach towards wood material utilization in construction as its strength achieves markedly higher values then common structural wooden elements and makes rapid erection of the building possible. Although there are great promises that the novel CLT structures will gain ground in high-rise buildings market with apparent benefits in sustainability and inhabitant comments regarding ambience and acoustics, it is important to analyse their structural health and hygro-thermal conditions. The highest risk of unfavourable hygro-thermal conditions is usually presented in location characterized by thermal bridge, such as foundation, window-wall, wall-roof and wall-floor junctions. It is also of significant importance to analyse junctions between materials, whether wood, composite, mortar or concrete. A certain combination of thermal and humidity conditions in exposed time causes mould growth initiation that may lead to deterioration of structural material and unhealthy indoor environment. In this case study, the moisture content and air-flow in the junction and open space in structural design details between the first floor (of concrete) housing joint warehouse and technical spaces and the residential upper floors made of CLT modules is analysed. Conditions leading to probable moisture-derived mould issues and design parameters leading to sufficient ventilation according to Mould Index modelling are presented.

The presented analysis deals with hygro-thermal numerical simulation and mould growth risk evaluation in cases representing common foundation structures of timber-framed houses in Finland. Three different structural approaches are addressed with estimation of potentially problematic elements during the building’s life cycle that may require special caution in design process. The studied cases include common building materials such as mineral wool, timber, bricks, concrete, EPS, and so on, and the key differences consist of building element configurations. The selected application for mould growth analysis predicts growth initiation and/or its stage in given climate conditions. The size of structural elements and their placement have a significant impact on hygro-thermal performance of a structure, and hence likely on the health of its indoor environment and the sustainability of the building too. Hygro-thermal analyses apply official weather data measured in Oulu region in Finland from 2009 to 2015 representing humid coastal conditions. The long-term analysis depicts hygro-thermal conditions inside the structure and on its layered interfaces and predicts mould growth initiation in selected positions. The numerical simulation indicates that applying less sensitive structural material on top of a building skin to protect timber-frame from humid external conditions would be beneficial. The conditions in wooden elements cause issues at a certain range of thermal conditions and sufficient exposure time. The study highlights problems that may occur in the ambient of foundation structures of common timber-framed houses.

The increasing role of services for business making has been recognised in the forest-based sector, yet a systematic analysis of this emerging phenomenon is lacking. The current study derives from service research three perspectives for analysis: services activities separate from primary production and manufacturing–processing, services outputs separate from tangible products, and service as strategic, that is, business model consideration how value is created. Document analyses have been carried out to examine how these perspectives are identifiable in the European-level bioeconomy and forest-based sector strategies, as well as in a number of major strategic partnerships beyond the bio-based industries, that is, the research and innovation programmes of processing industries, manufacturing, energy-efficient buildings and green vehicles. The upstream and downstream strategies tend to differ on their approach to services. This paper contributes to the forest sector research by introducing two disti...

Wood biomass for energy is largely produced in Europe from forest land resulting from silvicultural and management practices or from agricultural land in the form of fast growing plantations. The present paper reviews and compares the estimated current potentials for wood biomass production in 25 countries in Europe. The potentials are divided attending to these sources to identify the most suitable method of wood biomass production on a country level, based on its current forest and agriculture levels of production. Data has been collected and compiled from previous models and estimations. The total aggregated available potential in Europe is 76 Mm3 of wood biomass from the forests, with an additional 90 Mm3 from increasing the utilization of forest lands, and 98 Mm3 from fast growing plantations (dedicating 5% of current agricultural land). Germany and France showed high potentials both from agriculture and forest; Finland and Sweden had most of its potential from forest sources; and Spain, Pola...

Deep eutectic solvents (DESs) are a fairly new class of green solvents applied in various fields. This study investigates urea-based DES systems as novel pretreatments for cellulose nanofibril production. In the experiments, deep eutectic systems having urea and ammonium thiocyanate or guanidine hydrochloride as a second component were formed at 100 °C and then applied to disintegrate wood-derived cellulose fibers. The DES-pretreated fibers were nanofibrillated into three different levels of mechanical treatments with a microfluidizer, and their properties were analyzed. Moreover, nanofibril films were fabricated by solvent casting method. Both DES systems were able to loosen and swell the cellulose fiber structure as indicated by the increase in the lateral dimension of the fibers. Nonpretreated birch cellulose fibers had difficulties in mechanical nanofibrillation as clogging of the chamber occurred often. However, cellulose nanofibrils with widths ranging from 13.0 to 19.3 nm were successfully fabricated from DES-pretreated fibers with both systems. Translucent nanofibril films generated from DES-pretreated cellulose nanofibrils had good thermal stability and mechanical properties, with tensile strengths of approximately 135–189 MPa and elastic modulus of 6.4–7.7 GPa. Consequently, both urea-based DESs showed a high potential as environmentally friendly solvents in the manufacture of cellulose nanofibrils.

Cellulose and tannin are both abundant and biodegradable natural polymers. This study proposes a strategy to construct biohybrid films combining the characteristics of cationic cellulose nanofibrils (CCNFs) and tannin extract for film applications. Multi-functional biohybrid films with anti-oxidative and UV-adsorbing characteristics were successfully fabricated from CCNF and tannin mixtures with different mass ratios. The results indicated that pure CCNF could be endowed with multi-functionality by a small amount of introduced flavonoid-rich tannin extract. By adding 5% (w/w) of extract, CCNF-tannin film achieved good anti-oxidant and UV-shielding ability, and simultaneously obtained ca. 15% improved thermal stability and tensile strength of up to 160 ± 9 MPa. In addition, tannin extract was able to enhance the optical clarity of CCNF film with tailorable appearances. The biohybrid films essentially consisted of renewable materials, and they can potentially be exploited in sustainable applications such as biocomposites and packaging materials.

Building guidelines vary greatly from one country to another; hence, significant regional variations in climate patterns should be acknowledged in building design. This study applied the mathematical mould-growth model to simulate common residential single-family building structures in different locations across Finland. The aim of this work was to show the degree of significance to which local differences in climate can influence mould-growth risk in the time frame of a few years. The mould-growth scenarios were analysed in common house walls, and numerical hygrothermal simulations were carried out to determine the conditions inside the wall structures. The risk of mould growth on the structures in different locations was modelled during 6–10 years of exposure to local weather conditions. Significantly higher mould-growth risk was observed in coastal locations, whereas the drier inland and northernmost locations performed much better. The local climate conditions were seen to affect the structural mould ...

The possibility of using coffee silverskin, an industrial waste from the coffee roasting process, as an antifungal feedstock in wood preservative formulations was investigated. Silverskin hot water extract and its antifungal properties in vitro against Rhodonia (Poria) placenta, Gloeophyllum trabeum, and Trametes versicolor were characterized, and its in vitro effects on wood decay caused by Coniophora puteana were analyzed. A kinetic luminescent bacteria test was performed using Aliivibrio fischeri to measure the acute ecotoxicity of the silverskin extracts. The antifungal test showed 60–70% growth inhibition of the studied fungi at higher concentrations—3%—but did not meet the high inhibition—100%—of the commercial wood preservative. The phenolic compounds, such as chlorogenic acid and its derivatives, and caffeine derivatives, were the main constituents of the silverskin extracts and considered the responsible compounds of the fungal inhibition. The silverskin extracts were significantly less toxic than the commercial copper-based wood preservative. Revalorization of silverskin from industrial residues does not perform as a wood preservative but it remains a potential source of antifungal chemicals for wood preservative formulations.

Fire hazard associated to wood and wood-based products is a clear shortcoming of natural building materials and hence the use of fire retardants is mandated by national building codes. In this study, we have synthesized a simple and green fire retardant composite using magnesium hydroxide (Mg(OH)2) with casein protein and tested its performance as self-adhesive coating paste. The thermogravimetric analyses indicated that casein-magnesium composites are able to produce thermally stable insulating magnesium oxide (MgO) that suppresses the fire spread as a result of the synergistic combination of physical and chemical actions—the intumescent action of casein, formation of char and thermally stable MgO, and the simultaneous release of water vapor retained by the casein. The most effective performance was obtained with a sample (coating weight of 1080 g/m2) for which the ignition time of pinewood substrate was increased by 147%, while the smoke production rate and the peak heat release rate were decreased by 53% and 30%, respectively.

Nanocellulose is a competitive reinforcement material for use in biocomposite structures and fibrous products. In this study, adhesive mixtures of dicarboxylic acid cellulose nanofibrils (CNF) were dispersed into commercial polyvinyl acetate (PVAc) and starch adhesives, which were applied to Norway spruce (Picea abies) to assess their performance in wood joining. Single-lap joints were prepared and tested with PVAc mixtures with 0 to 0.64 wt% CNF and starch glue mixtures containing 0 to 1.07 wt% CNF. CNF suspensions having three concentrations (0.64, 0.96, and 1.28%) were compared. The results showed that the optimum amount of CNF, 0.48% suspensions, added to PVAc increased the average lap joint strength (EN 205:2003) by 74.5% when compared to control specimens with pure PVAc. Correspondingly, 0.96% CNF suspensions also enhanced the strength of starch adhesive by 34.5%. Lower and higher CNF concentrations showed clearly inferior performance.

Wood decay is addressed continuously within the wood industry through use and development of wood preservatives. The increasing awareness on the negative effects of many chemicals towards the environment is causing political restrictions in their use and creating more urgent need for research on green alternatives. This paper discusses some of the possible natural extracts for wood preserving applications and compares the analytical methods available for testing their behavior and efficiency against decay fungi. The results indicate that natural extracts have interesting chemical constituents that delay fungal growth but vary in efficiency depending on the chemical concentration and substrate used. Results also suggest that presence and redistribution of preservatives in wood during exposure trials can be assessed by spectral imaging methods although standardized methods are not available. 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The excellent thermal performance and low cost of concrete-sandwich walls have made them widely applied in residential buildings. However, their standard composition may require additional insulation in boreal and arctic climates, where improvements in thermal insulation are achieved mainly by applying additional insulation layers on the envelope surface. Although thick insulation will substantially improve the heat capacity of a structure, elevated temperatures and entrapped humidity can lead to favourable conditions for the initiation of mould growth. The present study simulates the thermal performance of a model house wall structure in relation to increased mould growth risk. The results indicate that added insulation may have a negative impact not only on the structure and material properties of structural elements, but also on the environmental health and comfort of residents. Furthermore, climate conditions are shown to be a significant factor in identifying an optimal insulation design based on thermal performance and structural health.

High powered computers and engineering computer systems allow designers to routinely simulate complex physical phenomena. The presented work deals with the analysis of two finite element method optimization techniques (First Order Method-FOM and Subproblem Approximation Method-SAM) implemented in the individual Design Optimization module in the Ansys software to analyze the behavior of real problems. A design optimization is a difficult mathematical process, intended to find the minimum or maximum of an objective function, which is mostly based on iterative procedure. Using optimization techniques in engineering designs requires detailed knowledge of the analyzed problem but also an ability to select the appropriate optimization method. The methods embedded in advanced computer software are based on different optimization techniques and their efficiency is significantly influenced by the specific character of a problem. The efficiency, robustness and accuracy of the methods are studied through strictly convex two-dimensional optimization problem, which is represented by volume minimization of two bars" plane frame structure subjected to maximal vertical displacement limit. Advantages and disadvantages of the methods are described and some practical tips provided which could be beneficial in any efficient engineering design by using an optimization method.

0, info:eu-repo/semantics/published

Although moisture has a decisive role in the permanence of cellulose and unprinted paper, its role in ink release from the surface of printed recovered papers remains unclear. This work aimed to determine whether various relative humidity levels in the artificial aging test affect ink release from the surface of the paper and its fibers when pulping cold-set offset printed newspapers in alkaline pulping conditions. The results showed that relative humidity variations from 30% to 70% negligibly affected ink release at 60 °C. However, compared with these lower humidity levels, exposure to 90% relative humidity for at least 25 h resulted in a higher ink content bound to fibers, a greater formation of visible dirt specks after pulping and a smaller formation of microscopic ink particles. In practical applications, the accurate estimation of climate effects during the storage and the transportation of recycled papers requires that humidity conditions are taken into account while performing artificial aging tests with paper products.