Using a unique 8-year data set (2010-2017) of phloem data, we studied the effect of temperature and precipitation on the phloem anatomy (conduit area, widths of ring, early and late phloem) and xylem-ring width in two coexisting temperate tree species, Picea abies and Fagus sylvatica, from three contrasting European temperate forest sites. Histometric analyses were performed on microcores taken from tree stems in autumn. We found high interannual variability and sensitivity of phloem anatomy and xylem-ring widths to precipitation and temperature; however, the responses were species- and site-specific. The contrasting response of xylem and phloem-ring widths of the same tree species to weather conditions was found at the two Slovenian sites generally well supplied with precipitation, while at the driest Czech site, the influence of weather factors on xylem and phloem ring widths was synchronised. Since widths of mean annual xylem and phloem increments were narrowest at the Czech site, this site is suggested to be most restrictive for the radial growth of both species. By influencing the seasonal patterns of xylem and phloem development, water availability appears to be the most important determinant of tissue- and species-specific responses to local weather conditions.
- Klíčová slova
- European beech, Norway spruce, anatomy, early phloem, late phloem, sieve element area, xylem-ring width,
- MeSH
- borovice * MeSH
- buk (rod) * MeSH
- floém MeSH
- jedle * MeSH
- podnebí MeSH
- smrk * fyziologie MeSH
- stromy fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
One way of satisfying increased market demand and simultaneously achieving a reduced environmental load in the industrial paper production is the use of fibrous agricultural residues. The aims of this study were i) to investigate the effect of alkaline - hydrodynamic cavitation (HC) pre-treatments on the delignification of Miscanthus × giganteus stalks (MGS) and ii) establishing the suitability of MGS as feedstock and their exploitation in pulp and paper manufacturing. It was demonstrated that the proposed treatment is an efficient delignification method for the non-wood fiber sources, such as miscanthus. A significant outcome of this work was the observation that HC treatment preserved the fibres lengths and surface quality of raw MGS, but at the same time increased the amount of kinked and curled fibers present in cavitated miscanthus fibers. The average miscanthus fiber length was found to be relatively short at 0.45 (±0.28) mm, while the slenderness ratio, the flexibility coefficient and Runkel ratio values were calculated to be 28.13, 38.16 and 1.62, respectively. The estimated physical properties of MGS pulp hand-sheets were 24.88 (±3.09) N m g-1 as the tensile index, 0.92 (±0.06) kPa m2 g-1 as the burst index and 4.0 (±0.37) mN m2 g-1 as the tear index. Overall the current work demonstrated effective use of hydrodynamic cavitation for improving the processing in pulp and paper manufacturing.
- Klíčová slova
- Agricultural residues, Chemical composition, Fiber characteristics, Non-wood pulp, Strength properties,
- MeSH
- hydrodynamika * MeSH
- koncentrace vodíkových iontů MeSH
- lignin chemie MeSH
- lipnicovité chemie MeSH
- papír * MeSH
- povrchové vlastnosti MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- lignin MeSH
BACKGROUND: Wood science and nanomaterials science interact together in two different aspects; a) fabrication of lignocellulosic nanomaterials derived from wood and plant-based sources and b) surface or bulk wood modification by nanoparticles. In this review, we attempt to visualize the impact of nanoparticles on the wood coating and preservation treatments based on a thorough registration of the patent databases. METHOD: The study was carried out as an overview of the scientifically most followed trends on nanoparticles utilization in wood science and wood protection depicted by recent universal filed patents. This review is exclusively targeted on the solid (timber) wood as a subject material. RESULTS: Utilization of mainly metal nanoparticles as photoprotection, antibacterial, antifungal, antiabrasive and functional component on wood modification treatments was found to be widely patented. Additionally, an apparent minimization in the emission of volatile organic compounds (VOCs) has been succeeded. CONCLUSION: Bulk wood preservation and more importantly, wood coating, splay the range of strengthening wood dimensional stability and biological degradation, against moisture absorption and fungi respectively. Nanoparticle materials have addressed various issues of wood science in a more efficient and environmental way than the traditional methods. Nevertheless, abundant tests and regulations are still needed before industrializing or recycling these products.
- Klíčová slova
- Patent, VOCs, metal nanoparticles, surface treatments, wood coatings, wood modification,
- MeSH
- antiinfekční látky farmakologie MeSH
- dřevo * MeSH
- formaldehyd analýza MeSH
- hydrofobní a hydrofilní interakce MeSH
- nanotechnologie * MeSH
- povrchové vlastnosti MeSH
- těkavé organické sloučeniny analýza MeSH
- ultrafialové záření MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antiinfekční látky MeSH
- formaldehyd MeSH
- těkavé organické sloučeniny MeSH
Agricultural and forest residues obtained after harvesting are promising renewable sources, suitable as a source of pulp for cellulose nanocrystal manufacturing. Cavitation-assisted softening of the lignin-carbohydrate matrix offers sample opportunity for cellulose fibril liberation and degradation of amorphous cellulose. The present work addresses cavitation assisted cellulose fibril and crystal liberation and film forming properties of the supernatant phase of treated agricultural and forest residues. The effectiveness of this method has been evaluated according to crystallinity indices and hydrogen bond energies, as measured by FT-IR analysis. It has been observed that the use of cavitation increased the crystallinity and caused partial removal and degradation of the lignin matrix. Overall, it appears that considerable improvement of crystallinity can be obtained from agricultural and forest residues through the use of cavitation.
- Klíčová slova
- Crystallinity, Forest biomass, Lignocellulose, Thin-film, Ultrasonication,
- MeSH
- chemie farmaceutická MeSH
- konformace sacharidů MeSH
- lignin chemie izolace a purifikace MeSH
- molekulární modely MeSH
- technologie zelené chemie MeSH
- ultrazvuk * MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- lignin MeSH
- lignocellulose MeSH Prohlížeč
- voda MeSH
