Volume 12 Issue 2

The Trametes versicolor genome is predicted to encode many enzymes that effectively degrade lignin, making it a potentially useful tool for biopulping. However, the wood degradation mechanism of T. versicolor is not clear. To identify the enzymes that contribute to lignocellulose degradation, changes in the T. versicolor transcriptome during growth on poplar wood, relative to growth on glucose medium, were evaluated. Eight hundred and fifty-three genes were differentially expressed, with 360 genes up-regulated and 493 genes were down-regulated on poplar wood. Notably, most genes involved in lignin degradation were up-regulated, including eight lignin peroxidase (LiP) genes. Genes encoding cellulose and hemicellulose degrading-enzymes were mostly down-regulated, including six endo-β-1,4-glucanase genes and three cellobiohydrolase I genes. These results characterized transcriptomic changes related to lignocellulose degradation. This information could be used to develop T. versicolor as a tool to improve the efficiency of lignin degradation or to provide a theoretical foundation for a new paper pulp manufacturing process.

There are a number of experimental and theoretical studies on the energy conversion of oil palm derivative biomass. Moreover, the potential of this abundant biomass residue for renewable energy in major producing countries in Southeast Asia has been well documented. In this study, the results of an equilibrium model of downdraft gasification of oil palm fronds (OPF), developed using the Aspen Plus chemical process simulator software, and its validation are presented. In addition, an optimization of the major output parameter of importance (i.e., the higher heating value of syngas) with respect to the main operating parameters (i.e., temperature, equivalence ratio (ER), and moisture content) was performed. The response surface method (RSM) was used to determine the mathematical relationship between the response of interest, which was the heating value of syngas, and the operating conditions. This method was used to further determine the conditions that would lead to optimum higher heating values of syngas. Optimum values identified by RSM were: oxidation zone temperature of 1000 °C, moisture content in the range of 4%, and an equivalence ratio of 0.35. These optimum operating conditions and the corresponding higher heating value of syngas were found to correspond with the experimental results.

The thermal properties of wood-plastic composites (WPCs) and typical heating floor substrates heated by an electrothermal film were studied. Their effects on human feelings and the human autonomic nerve system were also investigated. The temperature changes of the specimens during heating and cooling were analyzed with an infrared thermal imager. People’s subjective feelings of touching different materials were analyzed with a semantic differential (SD) technique, and their electrocardiography was recorded with a multi-channel physiological signal acquisition system. The thermal conductivity, temperature variation, tactile impression, and heart rate variability of WPCs and other heating floor substrates were investigated. The WPCs presented a markedly lower thermal conductivity and superior tactile impression compared with ceramic tile, which has a similar density to WPCs. There was a negative correlation between the scores of the warm-cool feeling and the density of the heating floor substrates under room temperature (19 °C ± 1 °C), and a positive correlation when heated (33 °C ± 1 °C). The thermal conductivity and heat storage capacity of WPC were higher than those of solid wood. Electric heating composite floors with a high comfort level and good thermal properties could be manufactured by combining WPCs and solid wood.

The sessile oak tree represents 10.5% of the forest area in Romania and is the most widespread indigenous oak species. To select the most suitable domain of use for sessile oak wood, certain dimensional and qualitative criteria were taken into consideration. The aim of the present study was to highlight the influence of some log characteristics (wood diameters and quality) on the efficiency in sessile oak veneer cutting. The authors used a group of sessile oak logs purchased from Targoviste in Southeast Romania. The results analysis indicates the influence of sessile oak log diameters on the veneer efficiency comparative with decorative veneer efficiency by estimation of the cumulative density function (CDF). Analyzing the quality of sessile oak logs, it was found that buds and insect holes were the most important defects that appeared. Also, the regression analysis indicates an acceptable level of the present defects and did not have a significant influence to the veneer cutting efficiency, upon the number of obtained veneer sheets and the surface area of special veneer sheets, respectively.

For the first time, the essential oil of Black spruce (Picea mariana) bark residue was obtained using two types of hydrodistillations: steam distillation (SD) and water distillation (WD). Both gave similar yields and compositions as analyzed using gas chromatography and mass spectrometry. The essential oil composition is turpentine-like with the predominance of α-pinene (40.6% SD; 40.5% WD) and β-pinene (33.9% SD; 25.9% WD), followed by hydrocarbon monoterpenes β-phellandrene (4.8% SD; 3.6% WD), 3-carene (4.1% SD; 3.1% WD), and limonene (4.0% SD; 3.7% WD). Hydrosol’s composition is rich in oxygenated compounds with α-terpineol (29.3% SD; 33.5% WD), trans-pinocarveol (5.2% SD; 3.7% WD), terpinen-4-ol (5.0% SD; 5.8% WD), verbenone (4.9% SD; 5.4% WD), borneol (4.9% SD; 3.9% WD), and pinocarvone (4.6% SD; 4.3% WD). These black spruce bark essential oils differ in composition from those from needles, which are commercially available and rich in bornyl acetate.