نتایج جستجو برای: poplar wood

تعداد نتایج: 42866  

2017
Cédric Montero Bruno Clair Tancrède Alméras Arie Van Der Lee Joseph Gril Arie van der Lee

Wood is a natural composite material with a complex multi-scale structure. Its stiffness is mainly due to crystalline cellulose fibrils reinforcing the cell walls. In order to quantify the contribution of cellulose to wood elastic properties in both tension and compression, the change in cellulose (004) lattice spacing (cellulose crystal strain) was measured by X-ray diffraction during a bendin...

2013
M. Evtyugina C. A. Alves A. I. Calvo T. Nunes L. Tarelho M. Duarte S. O. Prozil

Smoke from domestic wood burning has been identified as a major contributor to air pollution, motivating detailed emission measurements under controlled conditions. A series of experiments was performed to characterise the emissions from wood combustion in a fireplace and in a woodstove of two common species of trees grown in Spain: Pyrenean oak (Quercus pyrenaica) and black poplar (Populus nig...

2008
R. Boeva-Spiridonova E. Petkova N. Georgieva L. Yotova I. Spiridonov

The aim of the present work is to obtain a chemical-mechanical pulp (CMP) from poplar wood with improved properties, to be used in packing papers in place of more expensive softwood or hardwood pulp. For improving the CMP quality indicators, a preliminary treatment of the pulp has been carried out with a mixture of oxidizing enzymes produced from Phanerochaete chrysosporium, including lignin pe...

2006
Notburga Gierlinger Manfred Schwanninger

Confocal Raman microscopy was used to illustrate changes of molecular composition in secondary plant cell wall tissues of poplar wood. Two–dimensional spectral maps were acquired and chemical images calculated by integrating the intensity of characteristic spectral bands. This enabled direct visualization of the spatial variation of the lignin content without any chemical treatment or staining ...

Journal: :iranian journal of natural resources research 2012
neda ghorbanzadeh ali salehi ebrahim lashkar bolooki ehsan kahneh

poplar trees are becoming extremely important as fast growing species due to the increasing need for wood and decreasing productivity of some lands in iran. the present study aimed to find the effect of canopy of poplar clones as one of the most important effective factors on soil properties compared to the distances inter-row trees. five poplar clones and species included: populus euramericana...

Journal: :The New phytologist 2015
Shan-Shan Chang Françoise Quignard Tancrède Alméras Bruno Clair

In order to progress in the understanding of mechanical stress generation, the mesoporosity of the cell wall and its changes during maturation of poplar (Populus deltoides × P. nigra) tension wood (TW) and opposite wood (OW) were measured by nitrogen adsorption-desorption. Variations in the thickness of the gelatinous layer (G-layer) were also measured to clarify whether the mesoporosity change...

Journal: :Plant physiology 2011
Ruiqin Zhong Ryan L McCarthy Chanhui Lee Zheng-Hua Ye

Wood biomass is mainly made of secondary cell walls; hence, elucidation of the molecular mechanisms underlying the transcriptional regulation of secondary wall biosynthesis during wood formation will be instrumental to design strategies for genetic improvement of wood biomass. Here, we provide direct evidence demonstrating that the poplar (Populus trichocarpa) wood-associated NAC domain transcr...

2006
Audrey Zink-Sharp Walter G. KAUMAN

Engineered wood composites are being crafted with increasingly smaller and smaller components, yet a search of the literature indicates a lack of intra-ring mechanical property data for almost all commercial wood types, particularly the underutilized low density hardwoods. In addition, there is no universally accepted testing regime for determining micromechanical properties of wood samples. As...

2011
Rebecca Van Acker Véronique Storme Geert Goeminne Bart Ivens René Custers Dirk Aerts Wim Soetaert John Ralph Nicholas Santoro Jean-Charles Leplé Gilles Pilate Wout Boerjan

Background Global warming, environmental disasters, and increasing oil prices have catalyzed a worldwide trend to use plant biomass as a renewable source for liquid biofuels and bio-based materials. Plant biomass can be processed into fermentable sugars by enzymatic depolymerization of the cell wall polysaccharides, followed by fermentation. However, the presence of lignin in the cell wall cons...

2012
Heyu Chen Qian Lang Yilin Xu Zifeng Feng Guofeng Wu

The aim of this research was to study the physical and chemical performance of poplar wood treated by chemi-thermal modification. A thermal treatment was used to catalyze the effect of the methylolurea impregnated pre-treatment by curing the poplar wood at 160 °C under atmospheric conditions. The results showed that the thermal treatment played an important role in the chemical and mechanical p...

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