Effect of Steam Treatment on the Properties of Wood Cell Walls

Steam treatment is a hygrothermal method of potential industrial significance for improving the dimensional stability and durability of wood materials. The steaming results in different chemical and micromechanical changes in the nanostructured biocomposite that comprise a wood cell wall. In this study, spruce wood (Picea abies Karst.) that had been subjected to high-temperature steaming up to 180 °C was examined, using imaging Fourier Transform Infrared (FT-IR) microscopy and nanoindentation to track changes in the chemical structure and the micromechanical properties of the secondary cell wall. Similar changes in the chemical components, due to the steam treatment, were found in earlywood and latewood. A progressive degradation of the carbonyl groups in the glucuronic acid unit of xylan and a loss of mannose units in the glucomannan backbone, that is, a degradation of glucomannan, together with a loss of the CO group linked to the aromatic skeleton in lignin, was found. The development of the hygroscopic and micromechanical properties that occurred with an elevation in the steam temperature correlated well with this pattern of degradation in the constituents in the biocomposite matrix in the cell wall (hemicellulose and lignin)

Path planning results are synthesized by the VBAS algorithm to avoid a single regular obstacle.

(a) Motion results in a 2D plane. (b) Relationship between function and number of iterations.</p

Comparison of path planning results by the conventional BAS algorithm on four different maps.

(a) Single regular obstacle. (b) Single irregular obstacle. (c) Multiple regular obstacles. (d) Multiple irregular obstacles.</p

Comparing the path planning of the VBAS algorithm and APF under different types of obstacles.

Comparing the path planning of the VBAS algorithm and APF under different types of obstacles.</p

Path planning results are synthesized by the VBAS algorithm to avoid multiple regular obstacles.

(a) Motion results in a 2D plane. (b) Relationship between function and number of iterations.</p

Path planning process.

Path planning process.</p

S1 Dataset -

(XLSX)</p

Multiple irregular obstacles enlarged the view of the planned path part of the VBAS algorithm.

Multiple irregular obstacles enlarged the view of the planned path part of the VBAS algorithm.</p

Path planning results are synthesized by the VBAS algorithm to avoid a single irregular obstacle.

(a) Motion results in a 2D plane. (b) Relationship between function and number of iterations.</p

Two-dimensional simulation environment map.

(a) Real Environment Map. (b) Safety threshold environment map.</p