scholarly journals Hardness of Densified Wood in Relation to Changed Chemical Composition

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 506 ◽  
Author(s):  
Przemysław Mania ◽  
Miłosz Wróblewski ◽  
Adam Wójciak ◽  
Edward Roszyk ◽  
Waldemar Moliński
Keyword(s):  
Chemical Composition ◽  
Cell Walls ◽  
Lignin Content ◽  
Densified Wood ◽  
Chemical Components ◽  
Poplar Wood ◽  
Birch Wood ◽  
Partial Reduction ◽  
Structural Components ◽  
Before And After

The aim of this study was to evaluate some of the properties of densified poplar and birch wood earlier subjected to partial delignification of cell walls. The effects of delignification are presented as a comparison of the content of basic structural components in wood before and after chemical modification. In birch wood, the lignin content decreased by 20%, while that of cellulose decreased by 9.7% and that of hemicellulose decreased by 64.9%. In poplar, the lignin content decreased by 34.1%, that of cellulose decreaed by 13.5%, and that of hemicellulose decreased by 58.0%. The hardness of densified birch and poplar wood, after partial reduction of chemical components, was 147 and 111 MPa, respectively, and, compared with natural (non-densified) wood, was almost 4.5 times and 7 times higher, respectively. Poplar wood was more densified (without delignification 238% and after delignification 281%). In the case of birch wood, the density levels were 176% and 188%, respectively.

The chemical composition of poplar wood in relation to the species and the age of trees

2019 ◽  
Vol 107 ◽  
pp. 131-138
Author(s):  
DONATA KRUTUL ◽  
ANDRZEJ ANTCZAK ◽  
TERESA KŁOSIŃSKA ◽  
ANDRZEJ RADOMSKI ◽  
MICHAŁ DROŻDŻEK ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Populus Deltoides ◽  
Lignin Content ◽  
Populus Trichocarpa ◽  
Age And Growth ◽  
Tree Age ◽  
Cellulose Content ◽  
Populus Alba ◽  
Poplar Wood ◽  
Growth Environment

The chemical composition of poplar wood in relation to the species and age of trees. The contents of the following substances: mineral substances, extractives, cellulose, lignin, holocellulose, in wood from fastgrowing poplar species (Populus deltoides x maximowiczii and Populus trichocarpa Torr and A.Gray) aged 2.5, 3, 5 and 7 years were compared to the contents of the abovementioned substances in Populus nigra L. and Populus alba L. wood, aged about 30. According to other publications, the cellulose and lignin contents increase in line with the tree's age. On the other hand, the comparison of cellulose content in studied poplar wood showed that its content did not depend from the species of tree, age and growth environment. Whereas, the content of extractives in poplar wood was dependent from the species of tree and growth environment. The lignin content in Populus deltoides x maximowiczii and Populus trichocarpa wood did not depend from its age and was similar to the lignin content in 30-year-old P. nigra wood. 30-year-old wood of P. nigra and P. alba contained less holocellulose compared to its contents in P. deltoides x maximowiczii and P. trichocarpa wood, regardless of its age.

LIGNIFICATION AND IN VITRO CELL WALL DIGESTIBILITY OF PLANT PARTS

1969 ◽  
Vol 49 (4) ◽  
pp. 499-504 ◽  
Author(s):  
D. N. Mowat ◽  
M. L. Kwain ◽  
J. E. Winch
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Cell Walls ◽  
Lignin Content ◽  
Correlation Coefficients ◽  
Cell Wall Digestibility ◽  
Plant Parts ◽  
Two Samples ◽  
Dactylis Glomerata L

The in vitro cell wall digestibility and chemical composition were determined with a total of 56 forage samples. Two samples each of Dactylis glomerata L., Bromus inermis Leyss., Medicago sativa L., and Lotus corniculatus L. were collected at three maturities. Two samples of Symphtum officinale L. were collected at two maturities. All samples were later separated into leaf and stem portions. Wide variation existed in chemical composition and digestibility. The range in cell wall constituents was 23.9 to 79.8%, in acid detergent fiber 16.9 to 52.3%, and in lignin 3.7 to 19.1%. The in vitro cell wall digestibility varied from 16.6 to 77.5%. Correlation coefficients between lignin content and cell wall digestibility were higher when lignin was expressed as a percentage of dry matter rather than as a percentage of cell walls. In grasses, the relationship between lignin in cell walls and cell wall digestibility was linear. However, cell wall digestibility of legumes and Russian comfrey was not as low as expected from the content of lignin.

The chemical composition of poplar wood in relation to the species and age of trees

2019 ◽  
Vol 105 ◽  
pp. 125-132
Author(s):  
DONATA KRUTUL ◽  
ANDRZEJ ANTCZAK ◽  
TERESA KŁOSIŃSKA ◽  
MICHAŁ DROŻDŻEK ◽  
ANDRZEJ RADOMSKI ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Populus Deltoides ◽  
Lignin Content ◽  
Populus Trichocarpa ◽  
Age And Growth ◽  
Tree Age ◽  
Cellulose Content ◽  
Populus Alba ◽  
Poplar Wood ◽  
Growth Environment

The chemical composition of poplar wood in relation to the species and age of trees. The contents of the following substances: mineral substances, extractives, cellulose, lignin, holocellulose, in wood from fastgrowing poplar species (Populus deltoides x maximowiczii and Populus trichocarpa Torr and A.Gray) aged 2.5, 3, 5 and 7 years were compared to the contents of the abovementioned substances in Populus nigra L. and Populus alba L. wood, aged about 30. According to other publications, the cellulose and lignin contents increase in parallel with the tree's age. On the other hand, the comparison of cellulose content in poplar wood showed that its content did not depend from the species of tree, age and growth environment. Whereas, the content of extractives in poplar wood was dependent from the species of tree, age and growth environment. The lignin content increased slightly as a tree age, but its content in 7-year-old wood was already similar to the level to be found in the wood at the age of about 30 years. About 30-year-old wood of P. nigra and P. alba contained less holocellulose as compared to its contents in P. deltoides x maximowiczii and P. trichocarpa wood, regardless of its age.

scholarly journals Lignin Transformation of One-Year-Old Plants During Anaerobic Digestion (AD)

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 835 ◽  
Author(s):  
Hanna Waliszewska ◽  
Magdalena Zborowska ◽  
Agata Stachowiak-Wencek ◽  
Bogusława Waliszewska ◽  
Wojciech Czekała
Keyword(s):  
Anaerobic Digestion ◽  
Cell Walls ◽  
Fermentation Process ◽  
Developmental Stages ◽  
Lignin Content ◽  
Methane Fermentation ◽  
Before And After ◽  
Biomass Components ◽  
One Year ◽  
Syringyl To Guaiacyl Ratio

The aim of the research is to identify the changes which occur in lignin from miscanthus and sorghum, one of the main biomass components, as a result of an anaerobic digestion (AD) process. The percentage content and structure of lignin before and after the fermentation process were analysed using biomass harvested in two growing periods—before and after vegetation. It was shown that plants at different developmental stages differ in lignin content. During plant growth, the lignin structure also changes—the syringyl-to-guaiacyl ratio (S/G) increases, whereas the aliphatic and aromatic structure ratio (Al/Ar) decreases. The AD process leads to an increase in percentage lignin content in cell walls, and the increase is higher for plants harvested during vegetation. It has been shown in studies that the methane fermentation of miscanthus and sorghum produces waste containing a large amount of lignin, the structure of which is altered relative to native lignin. The quantity and the new, simplified structure of lignin create new possibilities for using this aromatic polymer.

Chemical composition of forest fuels affecting their thermal behavior

1986 ◽  
Vol 16 (4) ◽  
pp. 721-726 ◽  
Author(s):  
Janice M. Rogers ◽  
Ronald A. Susott ◽  
Rick G. Kelsey
Keyword(s):  
Chemical Composition ◽  
Thermal Behavior ◽  
Ponderosa Pine ◽  
Fire Behavior ◽  
Chemical Components ◽  
Plant Materials ◽  
Thermal Reactions ◽  
Forest Fuels ◽  
Before And After ◽  
Flaming Combustion

Flaming combustion is dependent upon the production of flammable volatiles that originate from the heating of the fuel materials. The thermal reactions that take place during this heating are determined by the chemical composition of the fuel. A knowledge of fuel chemistry and thermal reactivity can be useful in understanding and predicting fire behavior. Four plant materials were studied because their thermal decomposition curves showed unusually strong peaks from unknown combustible volatiles. The objective was to isolate and identify the chemical source of these volatiles. The tissues were methodically fractionated by following previously published techniques. Effects of each fractionation were carefully monitored by thermogravimetric analysis before and after treatment. Arabinogalactan was identified as the source of 325–350 °C volatiles from western larch (Larixoccidentalis Nutt.) wood. The major component of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) bark that decomposed above 400 °C was suberin. Foliage from gallberry (Ilexglabra (L.) Gray) and ponderosa pine (Pinusponderosa Laws.) contained cutin, which was responsible for their volatiles produced above 400 °C. The thermal behaviors of suberin and cutin reflect their similar chemical composition. The presence of these chemical components may produce similar thermal behavior in numerous other plant tissues.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

REPEATED LONG-TERM SPACE FLIGHTS: PROTEOMIC INVESTIGATIONS OF COSMONAUTS' BLOOD

2020 ◽  
Vol 54 (5) ◽  
pp. 15-22
Author(s):  
I.M. Larina ◽  
◽  
D.N. Kashirina ◽  
K.S. Kireev ◽  
A.I. Grigoriev ◽  
...  
Keyword(s):  
Bone Structure ◽  
Space Station ◽  
The Body ◽  
Coagulation Cascade ◽  
Chemical Components ◽  
Blood Proteins ◽  
Blood Indices ◽  
Before And After ◽  
Biochemical Indices

We performed the first ever comparative analysis of modifications in the proteome, ionogram and some other blood plasma biochemical indices of 18 male cosmonauts (44 ± 6 years of age) before and after maiden or repeated long-term missions to the Russian segment of the International space station (ISS RS). Levels of proteins, substrates and ions as well as chemical components were measured using the LC-MS-based proteomics and routine biochemical techniques. A total of 256 to 281 indices were investigated with the methods of descriptive statistic, regression analysis, and access to bioinformatics resources. It was shown that blood indices recovery from the maiden and repeated missions reflects changes in the body systems and goes at a various speed. The results of measurements made prior to launch and on day 7 after landing are dependent on the number of missions. The bioinformatics techniques showed that after maiden missions both the mediator proteins of alkaline phosphatase (AP) and blood proteins with reliably changing concentrations are associated with the bio-processes including stress, metabolism and DNA reparation, apoptosis, catabolism and proteolysis. During early re-adaptation from repeated missions the AP level was affected by bone remodeling, phosphorylation, angiogenesis and coagulation cascade suggesting a distinct and urgent trigger of the processes of bone structure and mineralization.

scholarly journals The chemical composition of Lessonia berteroana (ex L. nigrescens) in kelp harvest management and open access areas near Coquimbo, Chile

2018 ◽  
Vol 46 (2) ◽  
pp. 258-267
Author(s):  
J.M. Alonso Vega ◽  
Pedro H. Toledo
Keyword(s):  
Resource Management ◽  
Chemical Composition ◽  
Open Access ◽  
Environmental Changes ◽  
Chemical Components ◽  
Optimal Harvesting ◽  
Harvest Management ◽  
Species Population ◽  
Pressure Indicators ◽  
Lessonia Berteroana

Lessonia berteroana (ex L. nigrescens) is kelp freely harvested from Open Access Areas (OAA), and to some extent controlled, from Management and Exploitation Areas for Benthic Resources (MEABR). Harvesting pressures can change population dynamics, mainly in OAAs. In particular, harvesting may alter the chemical components of plants. Therefore, the aim of this study was to determine the harvesting effects on the chemical composition of L. berteroana from MEABR and OAA sampled during different seasons (spring and fall) and at two sites (Talquilla and Lagunillas) near Coquimbo (30°S), Chile. The crude protein (13.5 ± 1.0%), total lipids (0.9 ± 0.2%), crude fiber (16.3 ± 1.6%), ash (30.1 ± 1.5%), and nitrogen-free extract (39.2 ± 2.0%) contents of L. berteroana were within reference values for Laminariales species. Population descriptors and chemical analyses showed that harvesting had local effects, rather than being affected by a resource management strategy (OAA vs MEABR). The seasonal anticipator nature of L. berteroana may explain the detected seasonality of it's chemical composition. Regarding functional morphological structures, chemical composition in the fronds was more variable than in the stipes and perennial holdfast, probably since leaves are ephemeral structures susceptible to environmental changes and that play a functional, rather than structural, role in kelp. In the context of Chilean kelp resource management, monitoring chemical composition is useful for determining optimal harvesting periods to local scale and for deciding when commercially valuable compounds, such as alginate, should be extracted. These data also complement harvesting pressure indicators based on L. berteroana demographic parameters.

Effect of particle size and delignification on the rate of digestion of hemicellulose and cellulose by cellulase in mature pangola grass stems

1983 ◽  
Vol 34 (3) ◽  
pp. 241 ◽  
Author(s):  
CW Ford
Keyword(s):  
Particle Size ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Structural Features ◽  
Cell Wall Polysaccharides ◽  
Particle Size Reduction ◽  
Digitaria Decumbens ◽  
Hemicellulose Degradation ◽  
Before And After ◽  
The Difference

Stem cell walls of pangola grass (Digitaria decumbens) were ground to two particle sizes (c. 1 and 0.1 mm diameter), and incubated with cellulase (ex. Trichoderma viride) for varying times before and after delignification. Total cell walls finely ground (0.1 mm) with a Spex Shatterbox mill were initially degraded more rapidly (to 24 h) than delignified 1 mm particles. Thereafter the delignified material was solubilized to a greater extent. Subsequent specific determinations of cell wall polysaccharides indicated that delignification increased the rate of hemicellulose degradation to a greater extent than did particle size reduction, whereas the opposite was found for cellulose. The difference between delignified and Spex-ground residues, in terms of the amount of polysaccharide digested, was much greater for cellulose than hemicellulose. It is concluded that structural features play a more important role in limiting cellulase degradation of cellulose than does association with lignin, the reverse being so for hemicellulose.

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