Research Articles

The high-speed steel (HSS) cutting tool edge recession increase (VB) from milling wood of nine wood species with very different properties were analyzed. Theoretical simulations showed that the synergistic effect of the wood density (D), hard mineral contamination (HMC), and high temperature tribochemical reactions (HTTR), as well as initial edge recessions were important factors that accelerated wearing on the examined cutting edges.

The effects of lignin-combined manganese ion, iron ion, and lignin-combined iron and manganese on the decomposition of hydrogen peroxide were investigated. Elemental analysis and inductively coupled plasma-atomic emission spectrometry were used to analyze the chemical features of the lignin composites and the amount of metal ions present in the solution or adsorbed on lignin, respectively. The results showed that the main transition metal elements remaining in the precipitated lignin were Fe, Mn, and Cu. The hydrogen peroxide decomposition in the presence of lignin-combined transition metal was represented by pseudo-first-order kinetics, and the pseudo-first-order rate constant (kobs) of peroxide decomposition with lignin-combined iron was 0.0068 min-1, while it was 0.0063 min-1 in the presence of lignin-combined manganese. A synergistic effect of manganese and iron combined with lignin on peroxide decomposition was demonstrated, and a kobs value of 0.0053 min-1 was obtained. The mixed addition of magnesium sulfate (MgSO4), sodium silicate (Na2SiO3), and ethylene diamine tetraacetic acid disodium salt (Na2EDTA) resulted in an optimal reduction in peroxide decomposition when single lignin-combined metal ion existed. However, adding Na2EDTA alone had an optimal effect on the reduction of peroxide decomposition in the presence of lignin-combined iron and manganese, with a kobs value of 0.0004 min-1.

A simple procedure was evaluated to prepare cost-effective heteroatom self-doped porous carbons from edamame shell using a two-step carbonization and activation process. The morphological, structural, textural properties and N2/CO2 adsorption–desorption were investigated. The results showed that edamame shell, which is abundant in nitrogen and oxygen, is an ideal precursor for preparing heteroatom self-doped porous carbons. The N and O contents of the prepared activated carbons (ACs) ranged from 1.20 wt% to 1.81 wt% and 5.13 wt% to 9.98 wt%, respectively. Furthermore, the specific surface area of 1835 m2/g of the N and O doped ACs resulted in mainly microporosity, which suggested that it has promising potential for wide applications in the fields of catalysis, energy conversion, energy storage devices, and adsorption.

The possible use of formamidine sulfinic acid (FAS) for pre-bleaching of colored office paper in the stage of pulping was investigated. In addition, the effects of FAS pre-bleaching on different colors were examined. Colored office papers were mixed with white office paper at a 1:4 ratio. FAS was added as 0.25%, 0.50%, 0.75%, 1.00%, and 2.00% into the pulper. Reduction ability of colors with FAS were determined as yellow, red, green, and blue according to L*, a*, b*, ΔE, and reflectance spectrum at 220 nm to 900 nm wavelength. In other words, it was determined that FAS succeeded on the yellow, red, and green colored waste paper, but it failed on the blue colored waste paper at 10 minute pre-bleaching conditions. On the other hand, in mixed colored waste paper, which can better represent industrial applications, the color difference (ΔE) were calculated as 32.0 with 1% FAS pre-bleaching. This result is successful for pre-bleaching, which is an auxiliary process during re-pulping of waste paper.

The feasibility of using orange peel residues as a substrate for induced sporulation of Trichoderma asperellum was evaluated. The Box-Behnken matrix (BBM) design was used to screen the effects of several parameters, including the effect of pH, inoculum, and moisture under solid-state fermentation culture conditions. The study was performed in two experimental steps (screening and optimization). Moisture content and pH were determined to be the most influential parameters on spore production during the screening stage. A Box-Behnken design was used to optimize and to define the interaction of the selected parameters. The moisture content was determined as the most significant parameter affecting spore production. An inoculum of 1 × 106 spores g-1, pH 6.07, and moisture content of 69.0% was the combination of conditions observed to achieve the maximum production of 2.04 × 109 spores g-1. The experimental value of 2.16 × 109 spores g-1 (from the experimental model) showed a good fit to the regressed model, with a standard error of 5%. Based on this work, a high yield of spores was obtained at 144 h of cultivation time, indicating that it is a feasible approach to use orange peel as a substrate for biomass and spore production.

A new thermally conductive copper paper was prepared with cellulose pulp and ultrafine copper powder in a traditional paper making process. The thermal conductivity of the copper paper was studied in different weight ratios, and the surface morphology was observed by scanning electron microscopy (SEM). The results showed that the addition of copper powder enhanced the thermal conductivity of copper paper distinctly, with a maximum of up to 0.560 w•m-1•K-1 in the weight ratio of pulp/copper of 1:12, which was an increase of 143% compared with the paper without copper. Scanning electron microscopy images showed that copper papers consisted of copper powder particles distributing compactly on the fiber surface. The tensile index of copper paper decreased compared with the paper without filler. A calendaring process was used to improve the combination between copper particles and fibers and to enhance the thermal conductivity of copper paper.

The effects of spruce bark crude extracts were evaluated relative to basil (Ocimum basilicum L.) plantlet development and metabolic processes (cellular division and histo-anatomical modification) involved in breeding. Natural phenolic compounds were separated as crude extracts by conventional and green extraction techniques, in a primary biorefining process, from Picea abies L. waste bark. First, the influence of phenolic compounds, in different concentrations, on the basil plants’ main biosynthetic processes was analyzed. The mitotic indices and chromosomal aberrations of the plantlets were monitored. There was a significantly positive action of the studied bioproducts on basil root and stem growth, biomass accumulation, and photo-assimilating pigment synthesis. The natural polyphenols triggered an intensification of metabolic processes and cell division, yielding a high mitotic index and good development of vascular bundles. The results supported the possibility of exploiting spruce bark wastes by conversion into valuable bio-compounds, with uses as innovative products in green biotechnology, as simple growth bioregulators, for example, or for biotech crops.

Pleurotus species are edible mushrooms that possess the ability to degrade lignocellulose and are cultivated on lignocellulosic substrates to produce fruiting bodies that are appreciated for their nutritional and culinary values. Radial growth rate (ur), mycelial biomass, and intracellular glycogen and protein contents were evaluated in the colonies of two strains of P. ostreatus (strains 26 and 50) and one strain of P. pulmonarius (strain 35) grown on barley straw extract agar, corn stover extract agar (CSEA), wheat straw extract agar, and glucose-yeast extract agar (GYEA). The nutritional composition of the Pleurotus fruit bodies cultivated on barley straw, corn stover, and wheat straw were also determined. Of all of the strains, P. ostreatus 50 showed the highest ur on the CSEA and GYEA, and P. ostreatus 26 showed the greatest mycelial biomass production on the lignocellulosic waste-based agar media (LWAM). All of the Pleurotus strains showed the greatest and lowest glycogen contents on the CSEA and GYEA, respectively. These results showed that the LWAM are more suitable for mycelial growth than a glucose-based agar medium, and that Pleurotus fruit bodies cultivated on corn stover had the highest nutritional value compared with fruit bodies grown on the wheat and barley substrates.