Tree engineering is a young discipline utilizing trees as structural elements, where the determination of limit loads in tree trunks great importance. Simple numerical models underestimate load-bearing capacity green wood contrast to experimental bending tests. A well-known reason for this residual stress state living lowering compressive towards surface. This results an overall state, which in...

Abstract The wood photodegradation, including discolouration caused by exposure to UV and solar radiation, has been intensively studied, while the effect of artificial lighting on little investigated. In present study, three types light sources (LED, incandescent, fluorescent lamps) colour changes was evaluated. LEDs with high (6500 K) low (3000 correlated temperature were employed in experimen...

Surface carbonization, or charring, of wooden cladding boards is a promising, low impact process that can substitute inorganic coatings. The char surface inert and hydrophobic possibly long-lasting solution for exterior uses. To determine the performance surface-charred wood, several sorption experiments were established. Sapwood two hardwoods (aspen, birch) softwoods (pine, spruce) used as exp...

High-quality pallets are easier to repair and last longer. To obtain the high-quality parts necessary to build durable pallets requires grading and sorting by an automated inspection system. Ultrasonic sensing was selected for this application because 1) it is relatively inexpensive; 2) it can penetrate and characterize internal features of wood specimens; and 3) its effectiveness has been demo...

A combination of wildfires and defoliating insect outbreaks play an important role in the natural successional dynamics North American boreal mixedwood forests, which, long term, change post-disturbance composition structure forest stands. After stand-replacing disturbances (mainly wildfires), early hardwoods typically dominate affected areas. Provided enough time following disturbances, increa...

The physics of ultrasonic acoustic emissions ( A E s ) was investigated for AE transmission through w o o d and transducers. The physical properties measured were velocity, attenuation and frequeney composition ol" AEs produced by two sources: cavitation events in xylem and peticil lead breaks. T h e authors also measured the relative sensitivity of var ious combinations of ultrasound transduce...

Wild plants are considered promising natural eco-friendly resources for fibers. Leptadenia pyrotechnica is a xerophytic shrub that flourishes in sandy desert habitat with high biomass production; therefore, it could be potential resource The present study aimed to investigate the vegetation composition of L. communities and their correlation soil variables. Additionally, this evaluate anatomica...

INTRODUCTION. THE somewhat arbitrary classification of the wood decays caused by fungi into " brown " and " white " rots has in recent years been the subject of controversy, as it has been suggested that more accurate classification can be based on strictly chemical evidence regarding the effects of the various wood-rotting fungi on wood substance. So far as "brown" rots are concerned a suffici...

Abstract Bioenergy is a critical part of renewable energy solution to today’s energy crisis that threatens world economic growth. Corn ethanol has been growing rapidly in the past few years. Policy-makers and researchers alike are becoming aware that corn ethanol has some serious drawbacks. It adversely impacts food prices and is harsh on soil fertility. Lignocellulosic ethanol on the other han...

Generating accurate and unbiased wall-to-wall canopy height maps from airborne lidar data for large regions is useful to forest scientists and natural resource managers. However, mapping large areas often involves using lidar data from different projects, with varying acquisition parameters. In this work, we address the important question of whether one can accurately model canopy heights over ...