Treesearch

Many wood shakes and shingles have been replaced by composition or asphalt-based shingles. Nevertheless, wood shakes and shingles are still widely used on commercial structures and residential houses.

The durability and beauty of wood make it an attractive material for bowls, butcher blocks, and other items used to serve or prepare food. Wood also tends to be less prone to harbor bacteria than are some other materials such as plastic.

House paint can fail prematurely—the following identifies some reasons and remedies.

The effects of pretreatment by dilute acid and sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) on substrate morphology, cell wall physical and chemical structures, along with the subsequent enzymatic hydrolysis of lodgepole pine substrate were investigated. FE-SEM and TEM images of substrate structural morphological changes showed that SPORL pretreatment resulted in fiber separation, where SPORL high pH (4.2) pretreatment exhibited better fiber separation than SPORL low pH (1.9) pretreatment. Dilute acid pretreatment produced very poor fiber separation, consisting...

This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose into soluble sugars that cannot be economically recovered, but resulted in CSR that is easily recoverable through conventional centrifuge. It was found that the window for simultaneous recoveries of CSR and producing high...

Solution-state two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy of plant cell walls is a powerful tool for characterizing changes in cell wall chemistry during the hydrothermal pretreatment process of wheat straw for second-generation bioethanol production. One-bond 13C-1H NMR correlation spectroscopy, via an heteronuclear single quantum coherence experiment, revealed substantial lignin β-aryl ether cleavage, deacetylation via cleavage ofthe natural acetates at the 2-O-and 3-O-positions of xylan, and uronic acid depletion via cleavage of the (1 → 2)-linked 4-O-methyl-α-D-g...

To investigate the role of extractives on heat-induced discoloration of wood, samples of black locust (Robinia pseudoacacia) wood flour were extracted with various solvents prior to heat-treatment. Analysis of their color parameters and chromophoric structures showed that the chroma value of the unextracted sample decreased while that of the extracted sample increased after heat-treatment. Both samples showed broad diffuse reflectance UV-Vis (DRUV) absorption bands with maxima around 360-380 nm after heat-treatment due to the formation of conjugated double bonds, carbonyl functionalities,...

The International Nondestructive Testing and Evaluation of Wood Symposium Series was initiated by Washington State University and the USDA Forest Products Laboratory (FPL) in 1963 with the convening of a symposium on the topic of nondestructive testing of wood at FPL. Including that meeting, 17 symposia have been held during the last 50 years at various sites around the world that focus on nondestructive testing and evaluation of wood. The technical content of these symposia have been captured and published in hardcopy proceedings. The proceedings from this series of symposia are rather...

As wind energy production drives the manufacturing of wind turbine blades, the utilization of glass and carbon fiber composites as a material of choice continuously increases. Consequently, the needs for accurate structural design and material qualification and certification as well as the needs for aging predictions further underline the need for accurate constitutive characterization of composites. In the present paper we describe an outline of a recently developed methodology that utilizes mutliaxial robotically controlled testing combined with design optimization for the automated...

This paper is describing the preliminary results of an effort to validate a methodology developed for composite material constitutive characterization. This methodology involves using massive amounts of data produced from multiaxially tested coupons via a 6-DoF robotic system called NRL66.3 developed at the Naval Research Laboratory. The testing is followed by the employment of energy based design optimization principles to solve the inverse problem that determines the unknown parameters of the constitutive model under consideration. In order to validate identified constitutive models,...