Research Articles

Furniture manufacturers’ response to the demographic challenge of aging nations is an important issue. The number of seniors is rising worldwide. The aging process often results in multiple health implications, including weaker mobility, decrease in muscle mass, and change in anthropometrical dimensions of the human body. Thus, the furniture offered should be adjusted to the needs of an increasing group of senior customers. To identify seniors’ preferences in relation to characteristics of sitting furniture, international surveys with 627 respondents aged 60+ years were conducted in Poland, Germany, Denmark, Finland, Latvia, and Lithuania. The implementation of this data in the design process may result in creation of the market offer meeting seniors’ needs. Design and functionality features were examined to provide guidance for senior-friendly development of furniture for sitting. Among the most important findings is the clear preference of having an armchair with the high backrest reaching above the head, a chair with armrests and an upholstered backrest and seat. Furthermore, respondents paid attention to the durability of furniture, stain resistance of upholstery, and adaptation of the furniture to the user’s dimensions, e.g., having influence on the height and depth of the seat before the purchase.

A visualization method was used in this work for the 3D morphology of internal defects in wooden products using a Philips Brilliance 16 computed tomography (CT). To obtain a high-quality 3D digital model, the original images from the CT scan were segmented to manually color the cross- and vertical sections of the wooden specimen. Through coloring, the reconstructed model showed the accurate 3D morphology of internal defects, such as cracks, wormholes, and decay parts, as well as clear shapes of borer excrement, nails, bark, and wood parts of the specimen. The results suggest that this method provides precise 3D models of different types of defects in the wooden specimen. It can also accurately measure the size and angle of the defects at any position for further observation. This method can be effectively used for non-destructive testing of wooden products and wooden cultural relics and can provide accurate scales of defects and intuitive 3D models for wooden products and wooden cultural relics restoration.

The effects of nanoclay were studied relative to the physical, mechanical, optical, and morphological properties of chemimechanical pulping papers. Nanoclay was incorporated at 0%, 2%, 4%, 6%, 8%, or 10%. To increase the retention, 1% cationic starch was used in all test papers. Handsheets (60 g/m2 in weight) were tested to determine their physical, mechanical, optical, and morphological properties. Up to 2% nanoclay increased the tensile strength; at values greater than 2%, the tensile strength decreased. The addition of up to 4% nanoclay increased roughness; between 4% and 10% nanoclay, roughness decreased. With 10% nanoclay, the tear strength, burst strength, and brightness decreased, but the air resistance, opacity, and yellowness increased. Scanning electron microscopy showed that the nanoclay filled the pore spaces between fibers, thus increasing air resistance. X-ray diffraction patterns indicated an intercalated structure.

Clarinets are made with a variety of materials, e.g., plastic, graphite, porcelain, or even metal. However, the most commonly used material to make clarinets is wood. Today, African granadilla or African blackwood (Dalbergia melanoxylon) is the most popular and most widely used species by leading international companies in terms of clarinet production, because of its high density, color, fine texture, and exceptional durability. This species is also used to manufacture flutes, oboes, and bagpipes, making African blackwood one of the most valuable tree species in the world. However, the focus on the usage of a single species puts considerable pressure on a rare and endangered wood species. Therefore, this work aims to identify viable alternatives to African blackwood in terms of manufacturing clarinets as well as providing a similar combination of instrument characteristics that musicians and companies believe contribute to the value of the instrument, e.g., acoustics, aesthetics, and price.

This work aimed to comprehensively examine the pretreatment efficiency of oil palm empty fruit bunches (EFB) using two different types of deep eutectic solvent (DES) mixtures, i.e., choline chloride/imidazole (DES-I) and choline chloride/glycerol (DES-G) in terms of pretreated EFB structural composition and enzymatic hydrolysis. The influence of the pretreatment temperature (55 °C, 90 °C, 125 °C, 160 °C, and 195 °C), EFB to solvent ratio (1:5, 1:10, 1:15, and 1:20), and pretreatment time (2 h, 4 h, and 6 h) on the performance of pretreated EFB and the generated black liquor was examined. The optimal conditions for EFB pretreatment were 160 °C, 1:5 ratio, and 2 h using DES-I solvent, and 160 °C, 1:10 ratio and 4 h using DES-G solvent. The structural carbohydrates of empty fruit bunch pretreated with DES-I, DES-I EFB1 and DES-G, DES-G EFB2 increased to 66.1%, and 64.6%, respectively. The enzymatic hydrolysis of DES-I EFB1 resulted in higher glucan conversion (92.4%) compared to DES-G EFB2, indicating that DES-I solvent was more efficient than DES-G for EFB pretreatment. X-ray diffraction, Fourier transform infrared spectroscopy, and variable-pressure scanning electron microscopy confirmed the removal of lignin and hemicelluloses from EFB during pretreatment and enzymatic hydrolysis.

Effects of cellulase addition were assessed relative to the co-ensiling performance of air-dried corn stover (DCS) and cabbage waste (CW). The DCS and CW mixtures were co-ensiled with 0 to 0.3% of cellulase addition, and changes in composition, intermediates, and biological activity were characterized. The results showed that the addition of cellulase enhanced the decomposition of cellulose and hemicellulose by 2.51 to 6.93% and 3.41%, based on different dosages and compared with the control. Thus, the content of water-soluble carbohydrates increased. The acid content also increased from 5.8% for the control to the range 5.16 to 8.51% for the samples containing cellulase. Moreover, there was a shift from homolactic to heterolactic fermentation with prolonged ensiling time, coupled with the dominant lactic acid bacteria shifting from Paralactobacillus and Lactobacillus to more of Lactobacillus. Thus, the addition of cellulase improved the relative abundance of Lactobacillus. An assessment of fermentation quality, therefore, suggested that cellulase addition can improve the silage quality of DCS/CW during co-ensiling.

The removal performance and mechanism of Cr(VI) from aqueous solution was studied for a novel micro-nano particle kraft lignin biochar (BC) pyrolyzed at 400 to 700 °C. The physicochemical properties of BC were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption-desorption isotherms. The results illustrated that the BC had irregular micro- and nanoparticles with abundant pore structure and high BET surface area (111.1 m2/g). The FT-IR results showed that the lower pyrolysis temperature resulted in more oxygen-containing functional groups. The Cr(VI) adsorption capacity decreased with the pyrolysis temperature increasing from 400 to 700 °C, and the maximum percentage removal of Cr(VI) for BC obtained at 400 °C was 100% at pH 2, which suggested that the removal efficiency was mainly dependent on functional groups. Kinetic analysis demonstrated that Cr(VI) adsorption on BC fit well to the pseudo-second-order kinetic model. The adsorption data was well fitted with the Langmuir isotherm models, and the maximum adsorption capacity was 37.2 mg/g at 298K. The BC could be reused twice with Cr(VI) removal of 63.91% and was suitable for Cr(VI) contaminated waste-water treatment.

Compost tea has a lot of potential for sustainable agriculture. The suppressive effect of compost tea on damping-off disease in beans (Phaseolus vulgaris), caused by Rhizoctonia solani, was investigated. The physicochemical properties of the tested compost tea showed the presence of dissolved solids (7070 mgL-1), organic matter (1280 mgL-1), nitrate (3840 mgL-1), and ammonium (90.0 mgL-1). The concentrations of phosphorus, potassium, calcium, and magnesium in compost tea were 22.7, 1540, 214, and 2.40 mgL-1, respectively. The highest inhibition of R. solani growth at a concentration of 30% compost tea filtrate was 87.0% and it was completely inhibited at a concentration of 50%. The application of compost tea or chemical fungicide (Rizolex-T) significantly decreased the pre- and post-emergence of damping-off and enhanced the plants survival. In spite of the total phenol content in bean plants infected with R. solani (15.6 µg·g-1 fresh weight), the treatment of infected plants using compost tea and the Rizolex-T caused further elevation in the phenol content, to 17.5 and 14.7 µg·g-1 fresh weight, respectively. These findings support the use of compost tea as a potential alternative to synthetic fungicides to help achieve environmental sustainability and food safety in farming.

The morphological properties and particle size characteristics of micro- and nanofibrillated cellulose (NFC) and lignin-containing NFC (LNFC) produced by a microfluidizer processor were investigated. The effects mechanism of lignin-containing on the adsorption of NFC and the stable properties of organic dyes suspension were also studied. The results showed that the preparation process and final performance of NFC were affected by the key factors including lignin, homogenization pressure, and number of homogenization cycles. The increase in the homogeneity of the fibrillated cellulose was minor for the NFC samples, while LNFC samples showed a larger increase in the homogeneity of the particle size distribution. The influence of lignin was reflected both in improved fibrillation efficiency and in the final organic dye dispersion properties achieved by LNFC addition, primarily observed as deceased particle sizes and fibril dimensions. This study indicated that pollution-free dispersion of organic dyes can be realized through the application of lignin-containing NFC.

Fast and accurate evaluation of the physical and mechanical properties of engineering ‎materials is of particular importance. The in situ semi-destructive and non-destructive tests versus the ‎static tests for determining the time-consuming physical properties have replaced many traditional ‎methods with reasonable accuracies. Determining the density as one of ‎the most important qualitative and quantitative parameters in the inspection of wood and wood-based ‎products is of great importance. For this purpose, 33 wood specimens from 11 species with varying densities were tested by pin penetration probing. Results were compared with those from ‎the basic density values from traditional methods. The results showed an exponential relationship between the pin penetration depths ‎and the basic density considering the moisture conditions but without any problems. The coefficients of ‎determination while estimating the equality of the basic density via pin penetration probing with the actual ‎basic density for both the testing specimens and the control samples were always over ‎‎0.8. Henceforth, this methodology suggested that the density evaluation could inspire higher precision than what has been achieved in previous efforts.