Research Articles

The effects of wood species and panel connections on the vibration and heavy-weight impact sound insulation performance of cross-laminated timber (CLT) slabs were investigated. CLT panels (5-ply, 150 mm thick, 1 m wide, and 4.2 m long) made of larch (Larix kaempferi) and pine (Pinus densiflora) were manufactured with 30 mm thick laminae, considering three types of joints. Three CLT panels of the same species and joint type were connected using spline joints, butt joints, or half-lap joints to form 3 m wide and 4.2 m long slabs for testing. The floor impact sound insulation performance of the CLT slabs was measured according to KS F ISO 10140-3, using the standard heavy-weight impact source, a rubber ball. Additionally, four accelerometers were installed at 400 mm intervals beneath the CLT slabs to analyze the deflections and natural frequencies of the slabs. The results of the experiment indicated that there were no significant differences depending on the wood species and the CLT panel joints. These findings suggest that wood species and joint methods can be flexibly applied in the design of CLT slabs.

Among the heavy metals (HMs) whose concentrations in natural environments have risen considerably in the last era, chromium (Cr) is one of the most toxic. Because of the risks it poses to human and environmental health, it is of great importance to screen the variation in Cr contamination in the atmosphere and decrease the pollution. This study aimed to determine the proper tree species that can be used to monitor and reduce Cr contamination. For this aim, studies were conducted on Tilia tomentosa, Robinia pseudoacacia, Cedrus atlantica, Pseudotsuga menziesii, and Fraxinus excelsior species growing in Düzce, which is among the 5 most contaminated European towns according to the World Air Pollution report. Samples taken from these trees were examined, and changes in Cr concentration depending on species, organs, compass direction, and age range in the last 60 years were evaluated. Results indicated higher Cr pollution in recent years, consistent with higher traffic density, but that there was no consistent effect of compass direction. It was also determined that the tree species most appropriate for screening the variation in Cr contamination in the airborne were Tilia tomentosa, and the most appropriate species for decreasing pollution were Robinia pseudoacacia and Cedrus atlantica.

Bamboo is a fast-growing plant easily obtained in Malaysia. It is commonly used for constructing various solid structures including the guitar. Its unique sound quality makes it different from the traditional wooden guitar. The Yamaha guitar sound was used as reference for the generally preferred guitar characteristics. This work focused on the acoustic characteristics easily obtained using the frequency spectrum analysis via a PicoScope oscilloscope and spectrogram using Adobe Audition. A microphone was used for recording the string sound and yielding the frequency response function. The Fast Fourier Transform (FFT) spectra showed that the Yamaha guitar had less partials compared to the bamboo guitar, except string 4. Strings 1, 2, and 3 showed a regular signal from the Yamaha guitar whereas the bamboo guitar showed an irregular pattern with significant overtone. The intensity of the partials in the bamboo guitar displayed a recognizable pattern, i.e., a reduction of partial intensity amplitude proportional to increasing frequency in strings 4, 5, and 6. Some random partials appeared between the harmonics in string 1, 2, and 3 from bamboo guitar whereas the absence of partials in the Yamaha guitar could be due to the higher radiation coefficient of wood, which displays a different timbre.

Ginkgo biloba leaf (GBL) extract was evaluated as a wood preservative, considering its sustainable availability in forests and cities worldwide. Previous research has demonstrated the antibacterial and antifungal properties of GBL extracts. Based on this information, it was hypothesized that GBL extract could effectively combat wood decay. The wood preservation properties of GBL extracts were evaluated using the “Laboratory test method of natural decay resistance of wood” KS F 2213 (2018). Its performance was compared to that of ACQ-2, a commercial wood preservative. The GBL extract was tested against two common wood decay fungi, namely Fomitopsis palustris and Trametes versicolor. The results showed mass loss rates of 13.6% and 9.9% after culturing these fungi, respectively. Although the GBL extract did not surpass the performance of ACQ-2, it achieved a “resistant” grade according to KS F 2213 (2018). This indicates that GBL extract exhibits a significant wood preservation effect. Furthermore, the GBL extract retains the natural color of wood, which is an advantageous characteristic.

Chinese wooden furniture occupies a central role in the nation’s cultural and historical heritage, serving not only as practical household items for period classification, but also as symbols of social status and artistic achievement. Recently, a new wave of Chinese-style furniture that blends traditional design elements with modern aesthetics has gained considerable market attention and recognition. This paper utilizes Conjoint Analysis to thoroughly investigate and assess consumer preferences and the visual appeal of contemporary Chinese-style furniture, leveraging a combination of user experience surveys and eye-tracking technology. This study suggests a sustained social interest in the materiality of Chinese heritage, emphasizing its relevance in today’s culture. The findings show that in subjective evaluations, consumers prioritize material selection. Eye-tracking data reveals that “material,” particularly “redwood,” demands more intensive cognitive processing during the fixation stage. However, “decoration type” plays a dominant role in visual searches across multiple stages, indicating that consumers employ varied cognitive strategies when interacting with different product attributes. Additionally, consumers’ focus on backrests and pattern craftsmanship offers valuable insights into future market trends.

To investigate and elucidate the influencing factors and laws of double-roll coating ratio (CR) for papermaking reconstituted tobacco and to assess the effectiveness of CR in characterizing the finished product’s hot water soluble (HWS) content, base sheet (BS) specimens of reconstituted tobacco with varying bone-dry basis weights and moisture contents were prepared. These sheets were then coated with different physical indices of coating liquids using a small double-roll coater at different sheet speeds. Subsequently, the CR and HWS content of the finished product were analyzed. The results showed that when the viscosity of the coating liquid was > 280 mPa·s, the moisture content of the BS should be maintained between 18% and 22%, and the speed of the BS should be > 120 m/min; when the viscosity of the coating liquid is < 280 mPa·s, the moisture content of the BS should be maintained between 14% and 18%, and the speed of the BS should be > 120 m/min, so that higher HWS can be obtained in finished products. The bone-dry basis weight of the BS should be kept between 40 and 60 g/m². The suspension solid content of coating liquid should be <  9.5%.

This study explores the potential of nanocellulose-based hydrogel for microalgae cell attachment. The hydrogel, composed of cellulose nanofibrils (CNF) and carboxymethyl cellulose (CMC), indicates feasibility in biomedical and cell culturing applications. It qualifies as an excellent substrate for 3D printing bioink utilizing the liquid deposition modelling technique. The growth of Chlorella vulgaris cells in Bold Basal Media (BBM) solution exhibits similar trends for both the standard culture and the culture media incorporating the CNF/CMC hydrogel. It was observed that the ionic-bond crosslinkers of H₂SO₄ and CaCl₂ in hydrogel formation were more conducive to cell adhesion compared to using covalent-bond crosslinkers of epichlorohydrin. Microalgae cell attachment exhibited the increase of green hue on the hydrogel surfaces, which shows the potential of cell to grow in the presence of CNF/CMC hydrogel.

Deep eutectic-like solvents (DESs) are ideal green solvents for achieving depolymerization of kraft lignin under mild conditions. In this study, the impact of changes in chemical structures in hardwood kraft lignin (HKL), softwood kraft lignin (SKL), hydroxypropyl-modified hardwood kraft lignin (PHKL), and acetylated hardwood kraft lignin (AHKL) on depolymerization was investigated. The results indicated that structural modification can effectively adjust the depolymerization reaction of lignin. Under the depolymerization conditions (150 °C, 3 h, CHCl:p-TSOH), the depolymerization extent of HKL was 44.8%, which was 9.4% higher than that of SKL (35.4%). It was found that after hydroxypropyl modification of phenolic hydroxyl in HKL, the depolymerization extent of PHKL decreased to 29.5%, confirming that phenolic hydroxyl was the key functional group promoting lignin depolymerization. Acetylation modification of HKL can effectively increase the lignin depolymerization extent from 44.8% to 54.2%. The experimental results of lignin model compound addition confirmed that acetylation modification can effectively inhibit condensation reactions. The GPC analysis showed that the average molecular weight (M_w) of depolymerized oil was less than 800 g/mol and had a narrow polydispersity index (M_w/M_n < 1.2), making it an important precursor for high-value applications such as the preparation of aviation fuel.

Hard carbon (HC) is regarded as the most prospective anode material for sodium-ion batteries. Biomass HC is favored due to the advantages of being inexpensive and easily available. Herein, hydrothermal treatment of poplar lateral branches at 220 °C for 4 h was employed as the first synthesis step for HC precursor with yield of 48.5%. The obtained precursor was subjected to the second step of carbonization under nitrogen atmosphere at 1200 °C, 1400 °C, and 1600 °C for synthesis of HC anode materials. Advantages of two step synthesis were confirmed in terms of inorganic impurities elimination, HC yield, and electrochemical performance. Inorganic impurities reduced from 0.46% in poplar wood to 0.26% in precursor. The HC yield was 34.6% for precursor from hydrothermal treatment of poplar wood, which was much higher than HC yield of 18.5% from direct carbonization of poplar wood. The obtained HC anode materials manifested high capacity, strong rate performance, and long-term stability for sodium-ion batteries as indicated by the capacity of 333 mA h g^–1 at 0.1 C and 285 mA h g^–1 at 2 C, and capacity retention of 92.9% after 200 cycles at 1 C. This research provides an eco-friendly approach for the high-value utilization of woody biomass as anode material for sodium-ion batteries.

In view of the current problems of insufficient furniture innovation and uniform styling, this article introduces regional culture to conduct innovative strategic research on existing wooden furniture styling, trying to explore the connection between furniture and culture. Based on the methods of extension semantics and shape grammar, the traditional Chinese furniture Su-style stool is used as an example to demonstrate its feasibility. This work mainly applies extension semantics to illustrate regional culture and combines shape grammar to integrate the cultural elements and furniture shapes, thereby creating new wooden furniture forms with regional cultural characteristics. The article not only draws a genealogy chart of Suzhou’s regional culture, but it also extracts a number of semantics and graphics to describe Suzhou cultural characteristics. It expands the graphics into relevant elements as a replacement library to replace some of the DNA genes of the stool by shape grammar, allowing the new stool to carry the cultural memories of Suzhou. Finally, the work generated three design practices, which were evaluated by excellence evaluation method. In conclusion, the article demonstrated that the combination of extension semantics and shape grammar can effectively guide the design of wooden furniture with regional cultural characteristics.