نتایج جستجو برای: wood density
تعداد نتایج: 447006 فیلتر نتایج به سال:
wood farming and especially poplar plantation is a key answer to the increasing demand of raw materials in wood and cellulosic industries. according to the diversity of wood applications, taking into account the wood quality and grading by wood farmers/buyers as well as its quantity can lead to an optimal management of production and consumption. in this regard, it is necessary to introduce and...
in this research work, it was planned to study influences of hydrothermal treatment temperature, holding time and press temperature on wood density, spring back, moisture absorption as well as dimensional stability of combined-hydro-thermo-mechanically modified poplar wood. wood blocks were treated hydrothermally at temperatures 120, 150 and 180°c for holding time of 0, 30 and 90 min. afterward...
BACKGROUND AND AIMS Wood density is a key variable for understanding life history strategies in tropical trees. Differences in wood density and its radial variation were related to the shade-tolerance of six canopy tree species in seasonally dry tropical forest in Thailand. In addition, using tree ring measurements, the influence of tree size, age and annual increment on radial density gradient...
influences of temperature as well as holding time on physical and mechanical properties of fir wood were studied in this work during the oleothermal wood modification. wood samples were cut and treated oleothermally in the soybean oil at 200 and 230°c for the holding time of 1, 3 and 5 hours. weights and the dimensions were measured before and after treatment. bending strengths, water absorptio...
Wood contains the majority of the nutrients in tropical trees, yet controls over wood nutrient concentrations and their function are poorly understood. We measured wood nutrient concentrations in 106 tree species in 10 forest plots spanning a regional fertility gradient in Panama. For a subset of species, we quantified foliar nutrients and wood density to test whether wood nutrients scale with ...
Wood density and vessel characteristics are functionally interrelated, yet they may have distinct ecological associations. In a comparative study of 51 angiosperm species ranging from chaparral shrubs to riparian trees, we examined relationships among wood density and vessel traits and their ecological correlates. Mean vessel lumen area and vessel density (number mm(-2)) varied widely (7- to 10...
Wood density is considered a key plant trait, affecting mechanical and physiological performance, yet its biological meaning is still rather unclear. Accordingly we investigated the anatomical underpinnings of wood density in trees and shrubs. We measured wood density and anatomical traits in distal stems 4–10 mm diameter under bark in 24 Australian species. Proportions of wood components that ...
in this research, the effect of wood species and particle size on mechanicalproperties of wood plastic composites (wpc) made of fir (abies alba) and beech(fagus orientalis l.) sawdust and high density polyethylene (hdpe) wereinvestigated. wood plastic composite (wpc) were made with 30% hdpe in abatch process at 185˚c, at two particle sizes of 40 mesh and 80 mesh. maleicanhydride polypropylene (...
Wood density is thought to be an important indicator of plant life history because it is coupled to many aspects of whole-plant form and function. We used a hierarchical Bayesian approach to explain variation in mortality rates with wood density, drawing on data for 765,500 trees from 1639 species at 10 sites located across the Old and New World tropics. Mortality rates declined with increasing...
in this study, the possibility of producing wood-plastic panels was studied using two different blending methods including melt blend and dry blend. wood-plastic panels were made from recycled high density polyethylene (as resin) and mdf waste (as natural fiber) at 60, 70 and 80% by weight filler loading. nominal density and dimensions of the panels were 1g/cm3 and 35×35×1 cm, respectively. the...
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