Volume 11 Issue 4

The performance of nickel, cobalt, and copper supported on silica as catalysts was evaluated for the glycerol steam reforming (GSR) reaction. The samples were characterized by nitrogen-porosimetry according to Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), and inductively coupled plasma atomic emission spectroscopy (ICP-AES), while the deposited carbon on the catalytic surface was measured with a CHN-analyzer. Catalysts were studied in order to investigate the effect of the reaction temperature on (i) glycerol total conversion, (ii) glycerol conversion to gaseous products, (iii) hydrogen selectivity and yield, (iv) selectivity of gaseous products, and (v) selectivity of liquid products. The results showed that the Ni based on silica (Ni/Si) catalyst was more active and produced less liquid effluents than the catalysts that used an active metal such as Co or Cu. Moreover, the H2 yield from the Ni/Si catalyst was very close to the theoretical maximum predicted by thermodynamics, and the CO2 production was favoured in comparison to CO production, which is important for use in fuel cells.

Silver nanoparticles (AgNPs) were synthesized with wheat straw biomass at room temperature using light irradiation. The reaction conditions were optimized, including the light intensity, biomass concentration, NaCl addition, and reaction time. The silver nanoparticles fabricated at the optimum conditions (light intensity 60,000 lx, biomass concentration 2 mg/mL, and reaction time 90 min) were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and zeta potential. The TEM results showed that the silver nanoparticles were mostly spherical, with an average diameter of 17.2 nm. The zeta potential of AgNPs reached -21.6 mV. The XRD spectra showed that the AgNPs were highly crystalline, with four characteristic peaks. The FTIR of nanoparticles implied that alcohols and proteins may have a vital role in the formation and stability of AgNPs. The silver nanoparticles synthesized by wheat straw biomass revealed antimicrobial activity against Escherichia coli and Bacillus subtilis strains.

Southern pine (Pinus sp.) wood cubes were treated with ACQ solutions with wax modification and post-treated at 70 °C for 10 h with hot air circulation. The effects of wax concentrations in ACQ-treated southern pine on its dimensional stability and copper leaching performance were investigated. The ACQ/wax-treated wood exhibited improved water resistance during the water soak process. The testing of swelling and shrinkage performance of the treated wood showed that samples with a higher percentage of wax had higher resistance to water swelling and shrinkage. The samples with a lower percentage of wax addition had only a slight effect on the moisture swelling and shrinkage resistance. As a result, copper leaching from ACQ/wax-treated wood with a 2% wax concentration was reduced to a lower level compared to ACQ-treated wood. When the proportion of wax in ACQ preservative was less than 1%, a higher percentage of copper was leached from treated wood.

Corn stalk is one of the most abundant agricultural residues in China. In this experiment, corn stalks were hot-pressed to prepare formalin-free particleboard. Milled wood lignin (MWL) samples were isolated from original and hot-pressed corn stalks. To illuminate the self-bonding mechanism of binderless particleboard, the structural characteristics of original corn stalk, hot-pressed corn stalk, and MWL samples were thoroughly investigated by Fourier transform infrared spectroscopy (FT-IR), solid-state cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance spectroscopy (CP-MAS 13C-NMR), X-ray diffraction (XRD), carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR) and gel permeation chromatography(GPC). The degradation of hemicellulose and a portion of amorphous cellulose occurred during hot-pressing. Hot-pressing increased the crystallinity and crystallite size of cellulose in treated corn stalk. The analysis of MWL showed that hot-pressing resulted in corn stalk lignin depolymerization through cleavage of a substantial portion of the β-O-4 linkages in lignin, as well as the decrease of molecular weight of lignin in corn stalk. In addition, acid-catalyzed condensation occurred between lignin and xylose when liberated from hemicellulose. These results demonstrated that condensation between lignin and xylose may contribute to the self-bonding mechanism and improve board properties.

To meet both landscape aesthetics and health needs, the effects of different concentrations of volatile organic compounds (VOCs) from Pistacia chinensis Bunge (P. chinensis) and Juniperus chinensis cv. Kaizuka (J. chinensis) on mouse spontaneous behavior were studied during successive six-day experiments. The results were as follows: 1) The excitability of the mice and their total moving distance increased significantly upon exposure to low volatile concentrations of P. chinensis (P<0.05), whereas there was an opposite effect after exposure to J. chinensis. 2) The explorative capacity of mice was enhanced by J. chinensis; in contrast, P. chinensis treatment resulted in an opposite effect. 3) The scent of P. chinensis volatiles reduced mouse appetites while J. chinensis had the opposite effect. 4) P. chinensis volatiles helped enhance mouse tension. The number of fecal grains in the treatment group was always greater than that of the control group and increased with increasing volatile concentration to a number that was two times that of the controls when the volatile concentration reached a relatively high level. In contrast, in the J. chinensis environment, the mice were relatively relaxed, with overall numbers of fecal grains that were only 81.7% to 97.6% that of the controls. Overall, VOCs from J. chinensis had beneficial effects on mice. Therefore, more J. chinensis should be planted in urban green spaces. However, VOCs from P. chinensis could cause adverse effects on mice. Therefore, it is suggested to minimize their planting in city or repairing their branches to keep away from the smelling range of humans.

Process parameters of cross-laminated timber (CLT) fabricated with Japanese larch were evaluated. The process parameters were designed by using an orthogonal test including pressure, glue consumption, and adhesive. Both delamination and block shear tests were conducted on CLT in accordance with GB/T 26899 (2011). The results showed that the optimum process parameters were A2B3C2 including pressure (1.2 MPa), glue consumption (200 g/m2), and amount of adhesive (one-component polyurethane). The weight loss and moisture absorption increased when the temperature increased, but the block shear strength decreased as the temperature was raised from 20 °C to 230 °C.

To clarify how the fire performance of ultra-low density fiberboard (ULDF) can be improved by complex fire-retardants, the limiting oxygen index (LOI) and microstructure of ULDFs with different additive amounts of complex fire-retardants was analyzed. The char yield, chemical bonding, and thermostability of ULDFs treated by different temperatures were also tested. Results showed that the LOI values and compactness of ULDFs were increased with increased amounts of fire-retardants. Three steps of char yield curves in control fiberboard (CF) and mixed fiberboard (MF) were apparent. The preliminary degradation in lignin and cellulose of CF occurred at 300 °C. The cellulose had completely decomposed at 400 °C, but in the case of MF, the lignin and cellulose were not completely decomposed at 400 °C. It was shown that there are different ways to improve the fire resistance of ULDF using boron, nitrogen-phosphorus, silica, and halogen-based fire-retardants. The fiberboard with silicium compounds had the lowest mass loss in three stages and total mass loss. Compared with CF, MF had a lower mass loss. Furthermore, the exothermic peak for MF at around 400.0 °C was decreased, indicating that the fire resistance of ULDF was improved by the complex fire-retardants.

A flaxseed mucilage-based edible film was developed with the addition of glycerol as a plasticizer. Various concentrations of glycerol were blended into the extracted mucilage, and the developed films were studied in terms of physical, mechanical, and morphological properties. As the glycerol concentration was increased from 1 to 5 wt%, the elongation at break of the films prominently increased, whereas the tensile strength and Young’s modulus decreased. The film failed to form at 6 wt% glycerol inclusion. The developed film was slightly reddish and yellowish in color, with enhanced transparency as the glycerol concentration in the film increased. Overall, this work demonstrated that with the addition of glycerol as a plasticizer up to 5 wt%, a flaxseed mucilage-based edible film could be developed as a sustainable alternative for food and bioproduct coating or packaging.