Portable spectroscopic instruments are an interesting alternative for in-field and on-line measurements. However, the practical implementation of visible-near infrared (VIS-NIR) portable sensors in ...the forest sector is challenging due to operation in harsh environmental conditions and natural variability of wood itself. The objective of this work was to use spectroscopic methods as an alternative to visual grading of wood quality. Three portable spectrometers covering visible and near infrared range were used for the detection of selected naturally occurring wood defects, such as knots, decay, resin pockets and reaction wood. Measurements were performed on wooden discs collected during the harvesting process, without any conditioning or sample preparation. Two prototype instruments were developed by integrating commercially available micro-electro-mechanical systems with for-purpose selected lenses and light source. The prototype modules of spectrometers were driven by an Arduino controller. Data were transferred to the PC by USB serial port. Performance of all tested instruments was confronted by two discriminant methods. The best performing was the microNIR instrument, even though the performance of custom prototypes was also satisfactory. This work was an essential part of practical implementation of VIS-NIR spectroscopy for automatic grading of logs directly in the forest. Prototype low-cost spectrometers described here formed the basis for development of a prototype hyperspectral imaging solution tested during harvesting of trees within the frame of a practical demonstration in mountain forests.
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•FT-IR and NMR spectroscopies were used for the discrimination of samples with different geographical provenance.•T1ρ(H) values, obtained from variable contact time NMR experiments highlighted the ...differences between wood groups.•Principal component analysis of NMR and IR data allowed the most effective discrimination of wood due to provenance.
13C nuclear magnetic resonance and mid-infrared spectroscopies were used for characterizing changes in the chemical structure of wood polymers (cellulose, hemicellulose and lignin) in relation to the tree growth location. Samples of three provenances in Europe (Finland, Poland and Italy) were selected for studies. The requirement was to use untreated solid wood samples to minimize any manipulation to the nanostructure of native wood.
The results confirm that the chemical and physical properties of samples belonging to the same wood species (Picea abies Karst.) differ due to the origin. Both FT-IR and dynamic NMR spectroscopies were able to correctly discriminate samples originating from three different provenances in Europe. Such methods might be very useful for both, research and understanding of wood microstructure and its variability due to the growth conditions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Understanding the atomic-scale structure of wood microfibrils is essential for establishing fundamental properties in various wood-based research aspects, including moisture impact, wood ...modification, and pretreatment. In this study, we employed molecular dynamics simulations to investigate the arrangement of wood polymers, including cellulose, hemicellulose, and lignin, with a primary focus on the composition of softwood, specifically Norway Spruce wood. We assessed the accuracy of our molecular dynamics model by comparing it with available experimental data, such as density, Young’s modulus, and glass transition temperature, which ensures the reliability of our approach. A key aspect of our study involved modeling the active sorption site for water interaction with wood polymers. Our findings revealed that the interaction between water and hemicellulose, particularly within the hemicellulose–cellulose interphase, was the most prominent binding site. This observation aligns with prior research in this field, further strengthening the validity of our results.
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Systems found in nature are a valuable source of inspiration for several applications. Scientists and researchers from different fields (structural engineering, robotics, medicine, and materials ...science) use the concepts of biomimicking, biomimetics, and bioinspiration. More recently the possibility to benefit from solutions developed by nature has become of interest for sustainable architecture. Living organisms use smart, optimised, and elegant solutions to survive, thanks to continuous selection and mutation processes. For over 460 million years plants have been evolving in a constantly changing environment and have become well-adapted to different climatic conditions. Faced with several challenges (water loss, extreme temperatures, UV radiation, etc.) plants, for example, developed tissues with barrier properties. Furthermore, due to their immobility, plants are excellent biological materials for detecting climate phenomena. While animals, being mobile, developed other creative survival strategies through a long evolutionary process. Being exposed to various environments, they not only developed multifunctional surfaces, but also movements and a broad portfolio of sensing methods that increased their survival efficiency. Comprehensive analysis and evaluation of the adaptation strategies of plants (both static strategies and dynamic mechanisms) and animals to their environment in different climate zones are indispensable for transferring concepts from biology to architecture. Consequently, specific adaptation solutions might be implemented in new materials that will be used for building envelopes erected in the same climatic zones. Integrating length scales and mixing biological, chemical, and physical concepts for tailoring the properties of materials during preparation should allow for better designing of future smart materials. The process should lead to the development of active biomaterials that perform as interfaces between outdoor conditions and internal comfort. In that they should be able to regulate humidity, temperature, CO
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, and light as well as capture and filter pollutants; in addition, they should have self-assembling, self-cleaning, grafting, and self-healing properties. This contribution provides an analysis of several examples that represent the adaptation of organisms to various environments and are presented with the aim to inspire future researchers in the development of new building materials.
Kraft lignin, an industrially available by-product from the pulp and paper industry, has revealed enormous potential to be valorised into a wide range of chemicals and biomaterials in the last two ...decades. However, the understanding of lignin chemistry remains challenging due to its chemical complexity. The goal of this work was to investigate the effect of drying temperature on the chemical, physical, and hygroscopic properties of hardwood kraft lignin isolated from industrial black liquor and elucidate the molecular interactions occurring between water and kraft lignin. Sorption-desorption isotherms determined by dynamic vapour sorption (DVS) technique revealed that the drying process considerably affected the hygroscopicity of the lignin polymer. Moreover, analytical pyrolysis (Py–GC–MS), dynamic NIR spectra collected as a function of relative humidity (0–95%) during sorption-desorption cycles and principal component analysis (PCA), evidenced chemical differences between lignin dried at room (25 °C) temperature and mild oven (55 °C) conditions. The main spectral changes associated with the water sorption in kraft lignin samples were analyzed using difference spectrum technique. 2D NIR spectral correlation analysis provided water sorption mechanism of lignin polymer, disclosing for the first time the sequential order in which water vapour molecules interact with active sorption sites in kraft lignin.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Heterogeneity of kraft lignin is one of the main limitations for the development of high-performance applications. Therefore, refining lignin using organic solvents is a promising strategy to obtain ...homogenous fractions with controlled quality in terms of structure and properties. In this work, one-step refining processes for hardwood kraft lignin using nine organic solvents of different chemical nature and polarity were carried out with the aim of investigating and understanding the effect of the type of organic solvent on the quality of resulting fractions. Structural features of both soluble and insoluble lignin fractions were assessed by GPC, Py-GC-MS, and FTIR linked to PCA analysis. Moreover, functional properties such as physical appearance, hygroscopicity, antioxidant capacity, and thermal properties were evaluated. The results evidenced the relationship between the nature and polarity of the solvents and the properties of the obtained soluble and insoluble fractions.
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This study aims to characterize and valorize hemp residual biomass by a slow pyrolysis process. The volatile by-products of hemp carbonization were characterized by several methods (TGA, UV-VIS, TLC, ...Flash Prep-LC, UHPLC, QTOF-MS) to understand the pyrolysis reaction mechanisms and to identify the chemical products produced during the process. The obtained carbon yield was 29%, generating a gaseous stream composed of phenols and furans which was collected in four temperature ranges (F1 at 20-150 °C, F2 at 150-250 °C, F3 at 250-400 °C and F4 at 400-1000 °C). The obtained liquid fractions were separated into subfractions by flash chromatography. The total phenolic content (TPC) varied depending on the fraction but did not correlate with an increase in temperature or with a decrease in pH value. Compounds present in fractions F1, F3 and F4, being mainly phenolic molecules such as guaiacyl or syringyl derivatives issued from the lignin degradation, exhibit antioxidant capacity. The temperature of the pyrolysis process was positively correlated with detectable phenolic content, which can be explained by the decomposition order of the hemp chemical constituents. A detailed understanding of the chemical composition of pyrolysis products of hemp residuals allows for an assessment of their potential valorization routes and the future economic potential of underutilized biomass.
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Forest operations are in constant development to provide increasingly higher standards of economic and environmental sustainability. The latest innovation trends are concentrated in the generation, ...storage and management of data related to the harvesting process, timber products and logistics operations. Current technologies provide productivity and position, but only physical parameters are made available for timber products. The possibility of providing a comprehensive quality evaluation of roundwood early in the supply chain and linking the information to each log provides a new tool for optimization of the whole forest-timber supply chain. Current in-field methods for grading logs are based on visual rating scales, which are subjective, operator-dependent and time-consuming. As an alternative, a sensorized processor head was developed, featuring the following sensors: near infrared (NIR) spectrometer and hyperspectral cameras to identify surface defects, stress wave and time of flight sensors to estimate timber density, hydraulic flow sensor to estimate cross-cutting resistance and delimbing sensors to estimate branches number and approximate position. The prototype also deployed an RFID UHF system, which allowed the identification of the incoming tree and individually marked each log, relating the quality parameters recorded to the physical item and tracing it along the supply chain. The tested sensors were installed and designed to be independent, nevertheless, their integrated use provides a comprehensive evaluation of timber quality. This paper presents the technical solutions adopted, the main hindrances found and some preliminary results of the operative prototype as tested in laboratory and in forest operational conditions. Keywords: timber quality, processor head, sensors, NIR, cutting forces
•We analyse pine and oak samples in differing waterlogging conditions.•We perform dynamic analysis of samples (free-vibration and ultrasound velocity).•We use PLS models from FT-NIR spectra to ...predict dynamic/physical parameters.•Analysed properties decrease in pine sapwood already after short-term waterlogging.•Prediction models are proved to be reliable for conditioned samples.
Wood is one of the oldest building materials and, thanks to its favorable mechanical and technological properties, one of the most versatile. Due to its biological nature, wooden artefacts can undergo some alteration during their service life that can be caused by mechanical, environmental or biological agents.
Waterlogged and buried wood elements, present in wetlands and aquatic environments, are subject to modifications at the chemical and anatomical level, which also affect physical and related mechanical properties of the material.
The possibility to predict long-term performance and the rate of modification of mechanical/physical properties of the wood material in specific environmental conditions is crucial for proper design and optimal maintenance of submerged load-bearing timber structures. Therefore, prediction models to estimate selected material properties were developed within this study. For this purpose Fourier Transform near-infrared (FT-NIR) spectroscopy and multivariate analysis based on partial least-squares (PLS) were used. The models proved to be effective to predict selected dynamic and physical parameters of waterlogged samples. However, in order to include the effect of water saturation in the material on site further research is indispensable.
The possible detrimental effect on wood mechanical properties of waterlogging in differing environmental conditions is also discussed in this paper. Dynamic tests were performed on samples of two species, Quercus robur L. and Pinus sylvestris L., after 8years of deposition in two differing sites. Additionally, the results obtained from fresh and archaeological samples were compared.
No significant effects have been observed due to the depositional environment after short-term waterlogging. A more remarkable difference in the rate of the modification of dynamic and physical (density) properties can be attributed to differing natural features of the tested wooden species. It may be concluded that, in order to ensure a longer service-life of waterlogged timber structures, original wooden material should be properly selected, with regard to species, growth conditions, and log characteristics.
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Non-destructive spectroscopic methods (UV–Vis, FT–NIR and XRF) were utilized to evaluate the degradation state of natural polymers of contemporary wood exposed to short-term (eight years) ...waterlogging. Experimental samples included both softwood (Scots pine) and hardwood (Penduculate oak) degraded in two differing environments (peat and water). The species investigated exhibited diverse mechanisms of degradation. Differing sites also seem to have influenced degradation kinetics. Samples of both species placed in trenches filled with water show slightly more intense degradation. However, interpretation of FT–NIR spectra revealed that different woody polymers (functional groups) were degraded in waterlogged pine and oak respectively. Characteristic darker color was observed in oak wood with progressive waterlogging. XRF analysis identified deposition of iron in the external zone of oak samples. Partial Least Square prediction models for exposure time of wood decomposed in wet environment were also developed. The degradation stage of the short-term waterlogged samples was compared to archaeological oak dated at 13th century, and to pine dated at 17th century. Archaeological pine wood exhibits more intense degradation relative to the oak, even though the latter was 400 years older. Spectral analysis in the near-infrared range confirmed that amorphous and semi-crystalline regions of cellulose, hemicelluloses and lignin changed due to waterlogging. Conversely, the crystalline regions of cellulose seem not to be degraded.
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