bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and characterization of spherical lignocellulose-based anion exchanger from sugarcane bagasse
Authors: Cao Wei , Li Hao , Hong Yixia , Yang Ziyi , Fu Minglai
Published: August 2022

Biosorption is considered a promising technique for removing heavy metals from water. However, a biosorbent is usually prepared in the form of biomass powder that has drawbacks in stability and uniformity. Herein, a spherical lignocellulose-based anion exchanger (LCB-AE) was prepared from sugarcane bagasse through the method of dissolution-regeneration of biomass followed by quaternary ammonium modification. Dissolution-regeneration conditions of raw biomass were optimized, and the prepared materials were characterized by element composition analysis, pore-structure analysis (mercury intrusion porosimetry), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and carbon-13 nuclear magnetic resonance (13C-NMR) analyses. The LCB-AE has a macro-porous structure and a rough surface occupied mainly by quaternary ammonium and hydroxyl groups. Adsorption selectivity of LCB-AE follows the order of CrO42- > PO43- > SO42- > NO3-, and adsorption isotherms agree well with the Langmuir model, which suggests the experimental exchange abilities are approximately 0.8 to 0.9 mEq/g. These results show that LCB-AE as a new spherical biosorbent has the potential to be used for anions removal from water.
Analysis on the diffusion and mechanical properties of eucalyptus dried via supercritical carbon dioxide
Authors: Cao Ying , Wang Wei , Ma Wei
Published: August 2022

Using the molecular dynamics software Materials Studio, a micro-level carbon dioxide – cellulose model was established to study the supercritical carbon dioxide drying of eucalyptus wood. The change of the primary components of the eucalyptus wood cellulose were also studied, by simulating various pressures, i.e., 10, 15, 20, 25, and 30 Pa, and simulating a temperature of 323 K. Results showed that the diffusion coefficient of carbon dioxide decreases as the pressure increases, and it reaches the maximum at 20 Pa, which was confirmed by the number of hydrogen bonds in the carbon dioxide cellulose model. Combined with the comprehensive analysis of the mechanical parameters, the Poisson’s ratio γ and the ratio of bulk modulus to shear modulus (K/G) values of cellulose first increased and then decreased as the pressure increased, and the Young’s modulus increased as the pressure increased. From a microscopic point of view, the study shows that eucalyptus cellulose has good mechanical properties when dried by supercritical carbon dioxide under a pressure of 20 Pa. The simulation results of the dynamic model agreed well with the measured results, and the simulation results support the previous experimental data and the practical application results in production.
The economic impacts of Covid-19 on the forestry sector: A case study in Turkey
Authors: Komut Osman
Published: August 2022

The Covid 19 pandemic has led to considerable destruction of social and economic areas at a global level. This study aims to determine the economic impact of the Covid 19 pandemic on the Turkish forestry sector. In this context, 5 years (from 2017 to 2021) of wood-based product sales of an administrative unit, which carries out regional forestry activities in Turkey, were studied. The data concerning the product groups were subjected to a Laspeyres price index analysis based on the base period weight through the price and estimated price increase rate variables. In addition, correlation analysis was utilized to determine the relationships between the determined variables. The findings showed that the Covid 19 pandemic led to decreases in the Laspeyres price index values for the price and estimated price increase rates when compared with the pre-pandemic period, which was different on a product group’s basis. As a result, it can be said that the Covid 19 pandemic process created a considerable potential for a loss of income in wood-based products, which is one of the primary outputs of the forestry sector, and as of 2021, a recovery process has started.
Large-format preparation technology and electric heating performance of wooden electric heating flooring
Authors: Ti Pu , Liao Yonghua , Wang Quanyu , Qin Zhangji , Cai Qingyuan , Lin Zhi , Yuan Quanping
Published: August 2022

A large-format manufacturing process of electric heating floors for indoor heating was evaluated in this work using large-format high-density fiberboard as the substrate, carbon fiber paper as the electric heating element, and semi-cured melamine resin film as the bonding material to elevate its production efficiency. The semi-cured melamine resin film permeated the carbon fiber paper to form a glued structure via hot-pressing process, which improved the water resistance and insulation of the electric heating layer. The internal bonding strength of the floor reached 1.63 MPa with the enhanced waterproof properties. The temperature rise of both the electric heating floor and the assembled floors can reach 20.5 °C within 60 min under the voltage of 220 V. There was a small difference of approximately 2 °C in the ambient temperature between the heights of 0.6 m and 1.8 m above the running assembled electric heating floors. The power of the assembled 16 pieces of floors stabilized at 830 W after the continuous electrification for 12 h in this test condition, which demonstrated the comfortable and high-efficiency heating performance of the assembled electric heating floors.
Addition of polyvinylamine in chemi-thermomechanical pulp and kraft pulp and the effects on dewatering, strength, and air permeance
Authors: Sjöstrand Björn , Brolinson Annelie
Published: August 2022

The addition of polyvinylamine (PVAm) in the wet-end of the papermaking process was investigated. The changes in pulp drainage, vacuum dewatering, tensile strength, and air permeance were measured with and without PVAm. Both chemi-thermomechanical pulp (CTMP) and bleached kraft pulp were used. The dewatering and drainage abilities of the different pulps was examined by measuring the dewatering resistance (°SR), the water retention value (g/g), and the vacuum dewatering. The tensile strength and air permeance values were tested on paper sheets. The results showed that the initial dewatering was faster for pulps with PVAm, and this effect was greater for the CTMP and at higher basis weights. The strength increased when PVAm was added but only if the pulp was washed before sheet forming. The unwashed pulp with PVAm had worse formation, which resulted in lower tensile strength values. The air permeance of the sheets was higher with the addition of PVAm, primarily as a result of higher flocculation. Adding PVAm to the stock suspension in the wet-end of the paper machine has great potential for end-products that require high air permeance and tensile strength properties. PVAm could also act as a dewatering enhancing agent, but caution must be taken regarding the potential of formation problems.
Comparative analysis on the mechanical properties of mortise-tenon joints in heritage timber buildings with and without a ‘Que-Ti’ component
Authors: Li Yuanhe , Yao Lihong , Guo Yu , Liu Ruijng , Wu Yueqi , Jia Honglei , Yu Xia , Wang Ce , Hu Zhibang , Chen Chang
Published: August 2022

Three kinds of typical Chinese traditional mortise-tenon joints were tested. The effects of sparging on the deformation, hysteretic behavior, strength and stiffness degradation, and energy dissipation of the mortise-tenon joints were studied via low-cycle reversed loading tests with and without a ‘Que-Ti’ component. The results showed the following: the bearing capacity of the straight-tenon joint was the strongest, and the hysteretic loop of the through-tenon joint and half-tenon joint were asymmetric due to the asymmetry of the tenon form. The half-tenon joint was most likely to pull out the tenon, and the tenon pulling condition of the half-tenon joint can be effectively alleviated by adding a ‘Que-Ti’ component. From the perspective of energy consumption, it was found that the energy consumption capacity of the mortise-tenon joints after adding a ‘Que-Ti’ component was stronger than the joints without a ‘Que-Ti’ component. This shows that the ‘Que-Ti’ can be used as an effective component in terms of enhancing the mechanical properties of the mortise-tenon joints.
Preparation of poly(3-hydroxybutyrate-co-3-hydroxy-valerate) (PHBV)-based composites using poly(butylene adipate-co-terephthalate) (PBAT) and bagasse
Authors: Qin Yiqing , Jiang Guichang , Xu Qi , Li Peipei , Wei Shihang , Liu Jingyi
Published: August 2022

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) matrix composites were prepared by powder blending and a hot-pressing process with poly(butylene adipate-co-terephthalate) (PBAT) as a toughening agent and bagasse as a reinforcing agent. The effects of different contents of PBAT and bagasse on the mechanical properties, the thermal properties, and the section morphology of the composites were studied. By comparing the powder blending process with the conventional twin-screw melt extrusion blending process, it was found that the composites prepared by the powder blending process had better appearance and mechanical properties. With the increase of the PBAT content, the mechanical strength and modulus of the PHBV/PBAT composites decreased, but the flexibility increased. The addition of PBAT also caused the crystallinity of the composites to decrease and the thermal stability to increase. Based on the mass ratio of 60% PHBV and 40% PBAT, different contents of bagasse were added. It was found that the mechanical strengths of the composites were lower than that of the composites without bagasse, but the modulus was greatly improved. The crystallization properties of the composites improved, and the thermal stability decreased. This indicated that the addition of bagasse could reduce the material cost and improve the properties of PHBV.
Biochar extract compounds alter germination and growth of crop seed
Authors: Ma Jingwen , Quan Guixiang , Yan Jinlong , Ippolito James A. , Cui Liqiang , Wang Hui , Qiu Tianjing , Sun Yu
Published: August 2022

Positive or negative plant growth effects due to soluble organic biochar compounds are not well understood. Increasing quantities (0 g, 0.5 g, 2.5 g, and 5 g) of four different biochars were extracted with 0.1 M HCl, which were separated and marked as W, X, Y, and Z. Corn and rice seeds were treated with biochar extract solution. The rice straw Y and Z solutions positively affected corn germination, while the cotton straw Z solution negatively affected it. When differences were present, the biochar extract solutions always caused reduction in rice seed germination. The rice straw and cotton straw solutions tended to increase, the wheat straw Y and Z solutions tended to decrease, while little differences were evident in terms of the effects of the Spartina alterniflora solution on corn bud and root length when compared to the control. Increasing the biochar solution extract treatments reduced the rice bud and root length when compared to the control, especially with solution Z. Organic compounds, e.g., triethyl phosphate, 2,4-bisphenol, were present in the solutions, which likely promoted seed growth at lower concentrations. Determining the presence of biochar organic moieties helped with designing biochars for enhanced seed germination, growth, and crop productivity.
A novel strategy to intensify the dissolution of cellulose in deep eutectic solvents by partial chemical bonding
Authors: Feng Yanhong , Liu Guangliang , Sun Hang , Xu Chengcong , Wu Bo , Huang Canjun , Lei Bo
Published: August 2022

The relatively low solubility of cellulose in choline chloride-based deep eutectic solvents (DESs) restricts their practical application in the production industry. Here, cellulose was slightly oxidized into dialdehyde cellulose (DAC) at first, and then partial chemical bonding was introduced to intensify the dissolution process of cellulose in (choline chloride-resorcinol) DES. In this process, the solubility of cellulose in DES increased 10-fold, and the crystallinity of cellulose decreased over 24% while the oxidation level was lower than 20%. An intensified hydrogen bond network was revealed, which implied that cellulose components mainly acted as hydrogen bond donor after dissolution. A new class of DES containing cellulose was thus preliminarily established. The cellulose chains and the intensive hydrogen bond network also resulted in an increased viscosity and a conversion from Newtonian behavior to non-Newtonian behavior of dissolved samples. The phase transition behaviors of dissolved samples were gradually converted from crystallization to cool crystallization. The proposed and performed strategy is novel and scalable and will open a fresh perspective to achieve higher efficient dissolution of cellulose in DES and establish a new partially derivatized cellulose/DES system.
Effect of different size ratio and filling method on the characteristics of calcium silicate-filled paper
Authors: Xu Sheng , Xu Peng , Zhao Pu-Qi , Du Yu-Ting
Published: August 2022

Process conditions were investigated relative to the use of the fly ash pre-desilication-alkali lime sintering method to extract calcium silicate, which is a by-product of alumina co-production technology, for use as paper filler. The ratio of different fiber raw materials, filler filling ratio, and filling method were studied, and papermaking experiments were conducted. The results showed that calcium silicate filler at a higher proportion (40%) paper can still maintain high mechanical properties. Under the same filling ratio and filling method of calcium silicate filler, the comprehensive performance of softwood pulp and hardwood pulp papermaking paper was found to be better than that of deinked pulp paper.
“3D computational simulation and experimental validation of structured materials: Case studies of tissue papers
Authors: Morais Flávia P. , Curto Joana M. R.
Published: August 2022

The development and optimization of structured materials, such as tissue paper materials, benefit from modeling strategies that take into consideration its structural hierarchy at the fiber and the paper levels. The use of an innovative three-dimensional voxel approach to model both the fiber and the 3D paper structure were validated by comparison of the computational structures with the laboratory-made structures. The main goal of this work was to model tissue structures and obtain a computational implementation adapted for tissue products. The fibers were modeled in 3D according to their dimensions, and the structures produced by them were characterized using the Representative Elementary Volume (REV) and image analysis computational tools. This methodology made it possible to model the fibers according to their morphology, flexibility, and collapse, resulting in a tissue structure with thickness, porosity, relative bonding area, coverage, among other properties. The experimental design plan included the production and characterization of isotropic laboratory structures with basis weights of 20, 40, and 60 g/m2 with different eucalyptus fibers and beating degrees. With the aid of these advanced computational tools, mathematic models with predictive capacity for tissue properties such as softness, strength, and absorption can be developed.
Structural characteristics of eucalyptus lignin regulated through alkali cooking process
Authors: Shen Zheng , Liu Yi , Wei Xiaoxiao , Zhang Liming , Zeng Ling , Wang Shuangfei , Min Douyong
Published: August 2022

Understanding the basic chemical structure of lignin macromolecules can facilitate the development of lignin-based materials. In this study, the lignin structure was regulated through different alkali cooking conditions. The acid precipitated lignin from the spent cooking liquor was purified and fractionated with different organic solvents. The lignin samples with different structures were obtained by regulating the cooking time. The structural characteristics of the lignin preparations were systematically investigated. The results revealed that the structure of lignin was regulated by the heating time and the residence time during the cooking process. Non-condensed lignin was achieved after a specific cooking condition; it had higher molecular weight (9686 g/mol), more β-O-4 linkages (25.3/100Ar), but lower phenolic hydroxyl content (1.51 mmol/g) than the counterpart pulping with longer time duration. The non-condensed lignin also had excellent thermal stability. Compared with industrial lignin, the lignin with non-condensed structure can be modified to obtain phenolic resin materials with better performance. The non-condensed structure with the specific characteristics can broaden the valorization of lignin for producing biochemical and biomaterials.
Characterization of liquefied products from corn stalk in the presence of polyhydric alcohols with acid catalysis
Authors: Zhang Yan , Wang Huile , Zhao Huifang , Liu Zhong , Huang Jingjun , Yang Yujie , Chen Yu
Published: August 2022

Atmospheric liquefaction technology has been used widely and is an effective way of biomass component utilization. In this paper, the liquefied products obtained from corn stalk using polyhydric alcohols 1,2-propanediol (PG) mixed diethylene glycol (DEG) through acid catalysis under atmosphere pressure were characterized by various analytical technologies. The results indicated that 39 kinds of organic compounds were present in bio-oil, among which alcohols were the most, phenols were the second, and their relative contents were 70.7% and 25.6%, respectively. There were also some organic acids, ethers, esters, and ketones. More than 80% of these compounds had a carbon number less than 25. Carbon nuclear magnetic resonance spectra (13C-NMR) showed that different chemical shifts  (ppm) corresponded to various carbon types. The chemical composition of the residue from liquefaction was complex and contained a certain amount of large molecular substances that were difficult to degrade. It required more severe pyrolysis conditions than those of corn stalk. Results from X-Ray Diffraction (XRD) indicated the destruction of crystalline structure of carbohydrates and the cellulose molecules were cracked, indicating that the cellulose was degraded and the degree of liquefaction was high.
Mechanical properties of surface-compressed wood resulting from the compression ratio and density distribution
Authors: Gao Zhiqiang , Huang Rongfeng
Published: August 2022

Surface-compressed wood, with controllable mechanical properties according to the production process, could be utilized in timber products as a substitute for energy-intensive adhesives, concrete, and metals. The surface compression of wood was carried out in an open hot-pressing system at 180 °C with a compressed thickness of 2 to 18 mm. The surface-compressed wood was treated by atmospheric heat treatment or 0.30 MPa pressurized superheated-steam heat treatment at 180 °C for 2 h. This study investigated the mechanical properties of surface-compressed wood, namely, its bending, compression, and hardness properties. The results showed that the maximum density and average density of the compressed layer surpassed 1.10 g/cm3 and 0.80 g/cm3 when the compression ratio was 33%. Moreover, the surface-compressed wood with a sandwich density structure had properties that were comparable to, or even surpassed, raw wood, traditional compressed wood, and some engineered timber products. The specific strength (179 to 203 × 103 m2/s2) of surface-compressed wood was slightly higher than other wood-based materials (65 to 197 × 103 m2/s2). And the contribution of sandwich structure to MOR and MOE increase was positively correlated with wood surface density. The results obtained from this study could help engineers utilize more fast-growing wood and develop new products and wood connectors. This work may contribute toward the substantial use of surface-compressed wood in the building and construction industries with great benefits to the environment.
Anaerobic biodegradation of urea cross-linked starch: Effect of lignin on tensile properties
Authors: Majeed Zahid , Ajab Zainab , Mansor Nurlidia , Alqahtani Yahya S. , Mahnashi Mater H. , Alyami Bandar A. , Alqarni Ali O.
Published: August 2022

Lignin was used as a natural filler to improve the recalcitrance of environmentally friendly biocomposites made from starch. The tensile properties of lignin-starch biocomposites prepared by lignin reinforcing of urea cross-linked starch (UcS) were investigated in this study. The amount of lignin loaded into UcS was from 5 to 20%. These various compositions were buried in a microcosm of anaerobic soil. After 7 days of burial, biodegraded biocomposites were tested for changes in tensile characteristics. Changes in biodegradation were measured by comparing them to pristine samples, which were utilised as a benchmark for estimating. Through reinforcing polymeric starch in UcS, lignin was discovered to slow down the rate of loss in tensile characteristics of composites. With increasing lignin loadings from 5 to 20%, biodegraded biocomposites showed a constant reduction in elongation at break, Young’s modulus, and tensile strength. As a result, the biodegraded biocomposites’ metrics exhibited a substantially slower decrease than the control biodegraded film. The reduction in tensile properties of biodegraded biocomposites was explained by a significant difference (p < 0.05) using a paired t-test. This study found that lignin increased the strength of UcS and reduced the loss of tensile characteristics, probably as a result of soil microorganisms’ biodegradation activity being inhibited.
Preparation and characterization of hydrogels based on dehydroabietyl polyoxyethylene glycidyl ether grafted hydroxyethyl chitosans and their capability for loading and controlled release of chloramphenicol
Authors: Huang Xujuan , Ding Zhenqing , Cai Zhaosheng , Wang Ting , Yang Xinxin , Shang Shibin
Published: August 2022

Dehydroabietol polyoxyethylene(10) ether (DHA(EO)10H) was reacted with epichlorohydrin (ECH) using BF3 as catalyst and transformed into DHA(EO)10H-ECH, then dehydrochlorinated in the presence of sodium hydroxide and converted into dehydroabietyl polyoxyethylene(10) glycidyl ether (DHA(EO)10GE). Hydroxyethyl chitosan (HEC) was modified with DHA(EO)10GE, and a series of different DHA(EO)10GE-grafted HECs (DHA(EO)10GE-g-HECs) were prepared. Finally, the hydrogels based on DHA(EO)10GE-g-HECs were obtained through the reaction between genipin (GE) and DHA(EO)10GE-g-HECs. Effects of the grafting degree (DG) of DHA(EO)10GE and the dosage of GE on the gelation ability of mixed solution composed of DHA(EO)10GE-g-HECs and GE were investigated, and the behaviors of DHA(EO)10GE-g-HEC/GE hydrogels as carriers for loading chloramphenicol (CAP) were studied. It was found that the gelling time of the DHA(EO)10GE-g-HEC with high DG was longer than that with low DG, and a higher GE dosage could improve the capability of DHA(EO)10GE-g-HEC to form hydrogels. The relation between the cumulative release rate of CAP, which was loaded in DHA(EO)10GE-g-HEC/GE gel, and the release times in artificial intestinal fluid could be well described by Boltzmann function. Increasing the DG or decreasing the GE dosage could improve the final cumulative release.
Mycostimulator of chitinolytic activity: Thermodynamic studies and its activity against human and food-borne microbial pathogens
Authors: Bakri Marwah M. , Al-Rajhi Aisha M. H. , Abada Emad , Salem Olfat M.A. , Shater Abdel-Rahman M. , Mahmoud Mohamed S. , Abdel Ghany Tarek M.
Published: August 2022

Chitinolytic activity and antibiosis are gaining prominence in various biotechnological fields. Dead fungal biomass (DFB) was used as a mycostimulator of chitinase production and antibiosis by Aspergillus fumigatus. The presence of DFB stimulated the synthesis of various secondary metabolites by A. fumigatus that were detected by gas chromatography-mass spectrometry analysis such as 6,8-Di-C-á-glucosylluteolin; bistrimethylsilyl N-acetyl eicosasphinga-4,11-dienine; curan-17-oic acid, 19,20-dihydroxy-, methyl ester, (19S)-; spiro[5à-androstane-3,2′-thiazolidine; retinal; Androsta-1,4-dien-3-one; Panaxydol; Costunolide; Cyclo-(glycyl-L-tyrosyl); and 2-amino ethane thiolsulfuric acid. Chitinase activity was 42.9 Units/mL with the presence DFB, where it was 10.3 Units/mL without DFB. The maximum activity of chitinase was observed at 1.5 g of dead fungal biomass, at 4 h, 50 °C and pH 6. Thermodynamic properties showed ∆H° and ∆S° values of 126 KJ mol-1 and 432 J mol-1 K-1, respectively, indicating an endothermic reaction up to 60 °C. Deviation in ∆G° values confirmed that the reaction at 10 to 20 °C is a nonspontaneous reaction, and at 30 to 60 °C the reaction has a spontaneous nature. DFB encouraged the antimicrobial activity against Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Aspergillus fumigatus, Mucor circinelloides, and Candida albicans with 2.3, 2.2, 2.8, 0.8, 0.7, and 2.2 mm inhibition zones, respectively.
Comparative effects of pretreatment on composition and structure of corn stalk for biocomposites
Authors: Bin Yuejing , Li Sidan , Jiao Feng , Zhong Shan , Yuan Yuan
Published: August 2022

The outer surface of corn stalk (CS) plays a key role in the interfacial compatibility of non-wood-based panel products. To improve the bonding performance of the stalk surface, changes to the outer surface before and after four pretreatments (oxalic acid, oxalic acid + ultrasound, NaOH, NaOH + ultrasound) were investigated. Changes in the chemical composition, surface elements, aggregation structure, and microstructure of CS before and after pretreatment were analyzed. The results revealed that the wax layer, benzene–alcohol extract, and ash content of the outer surface of CS were decreased under different pretreatment conditions. The degree of reduction decreased in the order of NaOH + ultrasound > oxalic acid + ultrasound > NaOH > oxalic acid. The crystallinity of CS was obvious after pretreatment, and it increased in the order of oxalic acid + ultrasound > oxalic acid > NaOH + ultrasound > NaOH. Considering the properties of CS after pretreatment and the lignin activation modification of the CS surface, the optimal pretreatment conditions of CS were determined as oxalic acid + ultrasound, i.e., 5% oxalic acid and ultrasonication at 50 °C for 1 h.
Selective adsorption of metal ions on Salix psammophila fibre activated carbon
Authors: Wang Duoyu , Wang Xin , Wang Yang , Wang Xi
Published: August 2022

As an adsorbent of metal ions, activated carbon is often used to purify sewage. However, activated carbon fibres typically show similar adsorption capacity for different metal ions. Salix psammophila fibre (Spsf) was used as raw material to prepare activated carbon fibres (SP-FAC). This was modified with nitric acid (HNO3) to obtain HNO3-SP-FAC (FACHNO3). At 65 wt% concentration of HNO3, the impregnation ratio was 1:35 during 12 h, at 100 °C drying temperature, and the adsorption effect of FACHNO3 on Pb(II) was the best. At CHNO3 = 75 wt%, the impregnation ratio was 1:25. After an impregnation time of 36 h at the same drying temperature, the effect of FACHNO3 on Mn(II) was the best. At CHNO3 = 55 wt%, the impregnation ratio was 1:35, impregnation time was 36 h at 120 °C drying temperature, and the adsorption effect of FACHNO3 on Zn(II) was the best. These results indicate the existence of a close relationship between the pore structure of activated carbon fibres and the adsorption capacity of metal ions, and that the control variables changed the pore structure of activated carbon fibres so that it can achieve a competitive adsorption effect for different ions.
Evaluation of the effects of transition metal ions on the optical aging and whiteness of chemimechanical pulp
Authors: Nemati Mohammad , Samariha Ahmad
Published: August 2022

The negative effects of metal ions were addressed relative to the whiteness characteristic of chemomechanical pulp samples prepared. Proper solutions were considered to mitigate this adverse effect. The chemomechanical pulp samples were supplied in an unbleached form. The samples were wetted using ethylene diamine tetra acetic acid (EDTA) chelating agent, and then each of the samples was wetted with EDTA after drying with solutions containing the transitional metal ions. The results showed that the greatest whiteness reduction resulted from Fe2+ ions, whereas the smallest effect resulted from Al3+ ions. Wetting of the samples in various concentrations of the chelating agent (EDTA) had an optimum value in improving the whiteness characteristic of the paper. Thereafter, no change was created in whiteness improvement and brightness stability by increasing the concentration of EDTA. Increasing the aging time reduced the whiteness characteristic of the chemomechanical pulp.
Synthesis and characterization of novel nano-carbon mixture from Dabai (Canarium odontophyllum) nutshell
Authors: James Anthonette Anak , Rahman Md Rezaur , Huda Durul , Aqlan Faisal M. , Matin Mohammed Mahbubul , Bakri Muhammad Khusairy Bin , Kuok Kuok King , Rahman Mohammed Muzibur
Published: August 2022

The nanocarbon-based mixture was shown to be an effective adsorbent for removing dyes and heavy metals from wastewater via adsorption. The goal of this research was to prepare and investigate the properties of a bio-carbon mixture made from Dabai (Canarium odontophyllum) nutshell with the addition of titanium dioxide (TiO2) and montmorillonite (MMT) clay. Fourier transform infrared (FTIR) spectroscopy was used to determine the functional groups of raw carbon and potassium hydroxide (KOH)-activated carbon (AC). The FTIR analysis of the active carbon revealed that the active carbon had more surface chemistry than the non-AC. Scanning electron microscopy (SEM) analysis was used to compare the raw and AC morphologies and the developed nanocarbon. The results were confirmed using energy dispersive X-ray (EDX) analysis to verify the elements in the studied sample. The SEM analysis revealed that the structure of both the carbon samples was irregular, granular, and porous. BET analysis showed that nano-activated carbon had higher surface area compared to activated carbon itself. Response surface methodology (RSM) was used in Design-Expert 13.0 software for the sample composition development to achieve the best performance of the developed nanocarbon as an adsorbent.
Lignin peroxidase from the white-rot fungus Lentinus squarrosulus MPN12 and its application in the biodegradation of synthetic dyes and lignin
Authors: Giap Vu Dinh , Nghi Do Huu , Cuong Le Huu , Quynh Dang Thu
Published: August 2022

Lignin peroxidase (LiP), which has been studied extensively in white-rot basidiomycetes and their potential to degrade dyes from textile wastewater, plays a role in the biodegradation of lignin from pulp and paper industry wastewater, as well as agricultural waste. Lignin peroxidase (LsLiP) was successfully purified from the newly isolated Lentinus squarrosulus MPN12 with a 47.1-fold purification and a 15.7% yield. After 48 h-incubation, LsLiP was able to decolorize all tested dyes up to 92% for Acid Blue 62 (NY3), followed by Porocion Brilliant blue HGR (PB, 73.5%), Acid Blue 281 (NY5, 70.5%), Acid Blue 113 (IN13, 61%), Acid red 266 (NY7, 56%), and 34.5% for Acid red 299 (NY1), compared to the negative control with the heat-denatured enzyme. The biodegradation potential of LsLiP was further suggested by the change of lignin structure based on Fourier transform infrared (FTIR) analyses. Lignin structure was noticeably changed before and after LsLiP treatment, especially in the fingerprint regions (1600 to 1000 cm-1) and 2930 cm-1 corresponding to the stretching vibrations of various groups in lignin. Thus, LsLiP has potential application in both enzyme-based decolorization of synthetic dyes and lignin biodegradation.
Uplift capacity evaluation of light-framed wood structure’s roof-to-wall connections
Authors: Li Yuanhe , Yao Lihong , Song Yi , Liu Ruijng , Wu Yueqi , Chang Siyu , Yu Xia , Zhang Ziyang , Chen Chang
Published: August 2022

The load-displacement curves of six types of roof-to-wall connection joints were obtained through uplift experiments, while the mechanical properties of each type of joint were compared and analyzed, and the applicability of each joint was verified by the Foschi load-displacement curve model simulation. The specimens were made of three kinds of wood (Pinus sylvestris (PS), Spruce-Pine-Fir (SPF), and Douglas fir (DF)) and two different metal connectors (A-type and B-type), and then the monotonic pullout tests were conducted on each specimen. The failure modes of each group of specimens were analyzed, and the characteristic values analysis method was used to analyze and compare the characteristic values of the load-displacement curves of each specimen, including six characteristic values: maximum load, yield load, deformation capacity, energy dissipation capacity, ductility ratio, and initial stiffness. The results showed that the load capacity of TA group (specimens with A-type metal connectors) was much greater than that of TB group (specimens with B-type metal connectors). The specimens made of DF had the best mechanical performance, but the specimens of DF group were prone to brittle failure. Finally, the fitting parameters of the Foschi model applicable to such joints were obtained.
Investigating the characteristics of a natural fiber composite fabricated from 9,9′-bis(aryl)fluorene-modified nanocellulose and bamboo fiber
Authors: Sefat Khan Md , Kurose Takashi , Yamada Masahiro , Ito Hiroshi , Shibata Shinichi
Published: August 2022

A composite fabricated from 9,9′-bis(aryl)fluorene-modified nanocellulose (FCF) and bamboo fiber was studied to explore its processing conditions and limitations. The FCF acted as a binding agent, and bamboo fibers were used as structural reinforcement. Two types of FCF were fabricated and studied: hydroxy and epoxy functional groups with FCF. The FCF solution was homogenized and coated on bamboo fiber sheets. These sheets were laminated with FCF by hot-pressing at various temperatures, pressures, and weight fractions. Flexural modulus and strength were determined at each processing condition. Epoxy type FCF composites exhibited superior flexural performance compared to the hydroxy type. The epoxy type showed better homogeneous dispersion, which increased interfacial area between fibers. The optimal processing temperature was 230 °C. It was considered that thermal degradation occurred above 250 °C and chemical reaction between binder and bamboo was not enough below 210 °C. Flexural performance in the composites showed that approximately 10 MPa was structurally better due to increase of contact area among fibers, which was crushed flat by pressure.
Tensile properties of silicone biocomposite reinforced with waste material (Hevea brasiliensis sawdust): Experimental and numerical approach
Authors: Noor Haris Noorainol Faiz , Yahaya Mohd Azman , Mahmud Jamaluddin
Published: August 2022

Hevea brasiliensis wood becomes residue at plantations in Malaysia. In this study, these residues were reinforced into silicone rubber to produce a new soft biocomposite (Hevea brasiliensis-silicone biocomposite). The newly introduced soft biocomposite has potential for use in cushioning and sealing applications. The specimens were prepared with five different compositions (0 wt%, 4 wt%, 8 wt%, 12 wt%, and 16 wt% fiber content). Tensile tests were conducted according to ASTM D412 (2008) to assess the mechanical properties. Morphological characteristics were analyzed from the fractured surface of specimens. Stress-stretch data was used to quantify the non-linear tensile behavior, which was based on Neo-Hookean, Mooney-Rivlin, and Ogden hyperelastic constitutive equations. An increase in fiber content improved the modulus of silicone rubber. However, it reduced the flexibility and elastic properties of the silicone rubber biocomposite. The increasing material constant values supported these findings. The hyperelastic models accurately represented the behavior of the Hevea brasiliensis-silicone biocomposite. This study contributes knowledge towards a better understanding of the mechanical behavior of Hevea brasiliensis-silicone biocomposites.
Mechanical performance of three types of connections used in orthogonal ribbed beams made of poplar laminated veneer lumber
Authors: Liu Yan , Chen Jing , Ma Hongwei , Gong Meng , Zhang Linfeng
Published: August 2022

This study elucidated the mechanical performance of different connections used in orthogonal ribbed beams made of poplar laminated veneer lumber (LVL). Three types of connections (namely, U-, T-, and L-shape) were fabricated and used to connect the second beam and the middle part of a main beam to form an orthogonal rib beam. A concentrated load was applied to the intersection between the main beam and the second beam. The results showed: (1) all three types of ribbed beam connection specimens showed good connecting performance and the ductile failure, including the pull-out of partial self-tapping screws, crushing of LVL at the end of the ribbed beam, and connection failure; (2) the variation of load capacity of JD2-type specimens was approximately 3.2%, which was smaller than that of the JD1- and JD3-type specimens, slightly less than 10%; (3) the ultimate bearing capacity of a connection specimen was proportional to the number of self-tapping screws; and (4) the mechanical performance of the U-shaped connection specimens was worse than that of the L-and T-shaped connection specimens. The L-shaped connection was recommended due to its better mechanical performance, simpler configuration, and more convenient fabrication.
Improved yields of high value-added ketones in bio-oil from biomass fast pyrolysis employing ZnO-modified magnesium aluminum spinel catalys
Authors: Yao Di , Bi Dongmei , Zhao An , Liu Jia , Liu Jing , Li Bozheng
Published: August 2022

Ketones are an important class of multi-purpose products used for the production of high value-added chemicals. Herein, a novel method for the generation of methylcyclopentenone and pyridone via the modification of a magnesium aluminum spinel catalyst is proposed. In this study, zinc oxide, magnesium aluminum spinel, and ZnO-loaded magnesium aluminum spinel were used as catalysts for the catalytic pyrolysis of rape straw, corn stalk, and camphorwood powder at different reaction temperatures. Experimental results showed that different experimental temperatures and catalyst types played a crucial role in the formation of methylcyclopentenone and pyridone. Catalytic pyrolysis of rape straw with ZnO-loaded magnesium aluminum spinel increased the yield of methylcyclopentenone by greater than 6-fold compared to the yield without the catalyst, and the catalytic pyrolysis of corn stover increased the production of pyridone to 12.4%. The increase was primarily attributed to the conversion of cellulose and hemicellulose to ketones promoted by the ZnO-loaded magnesium aluminum spinel. These findings demonstrated that ZnO-loaded magnesium aluminum spinel catalysts can provide a new approach for enhancing the yield of methylcyclopentenone and pyridone during biomass fast pyrolysis.
Characterization of cellulose-nanofiber-modified fibrillated lyocell fiber separator
Authors: Song Huan , Yang Jun , Yang Yu , Yang Qing , Hu Jian
Published: August 2022

A fibrillated lyocell fiber-based separator was prepared using lyocell fibers and was modified with cellulose nanofibers. The effects of the cellulose nanofiber addition on the tensile properties, electrical properties, pore structure, liquid absorption properties, and equivalent series resistance of the separators were studied. It was found that adding an appropriate amount of cellulose nanofibers to the fibrillated lyocell fiber separator can improve the tensile strength, elongation at break, breakdown voltage, and equivalent series resistance value of the separator; reduce the pore size and porosity of the separator; and improve the pore size distribution. Moreover, the separator modified with 4% cellulose nanofibers yielded a favorable combination of properties, with a tensile strength of 0.645 kN/m, a mean flow pore diameter of 0.771 μm, a porosity of 88.4%, a capillary rise in paper of 30.7 mm/10 min, and an equivalent series resistance value of 2.46 Ω.
Effects of thermal treatment on physical properties of teak veneer (Tectona grandis)
Authors: Bouaphavong Douangta , Jarusombiti Songklod , Veenin Teera , Phonetip Khamtan , Soukphaxay Khonethong
Published: August 2022

Thermo treatment on veneer has been recognized as environmentally friendly and can modify wood properties. The objectives of this study were to investigate mass loss of thermo-teak veneer, to assess the density changes, and to examine shrinkage based on different levels of temperature at different time lengths. The temperatures were 180, 200, 220, and 240 °C applied at three different lengths of time, i.e., 4, 8, and 12 min on teak veneer sheets. The results showed that the mass loss at the temperature of 180, 200, 220, and 240 °C were not significantly different. Density changes were significant depending on the level of temperatures. Percentage of density decrease changed from 3.85% to 15.69% at temperatures ranging from 180 to 240 °C but the length of time (4, 8, and 12 min of thermal treatment) did not have a significant effect. The mass loss ranged from 5.90% to 17.66%.
Valorization of bioactive compounds from residual saffron biomass (Crocus sativus L.) to obtain high value added dermato-cosmetic products
Authors: Turcov Delia , Barna Ana Simona , Apreutesei Ciuperca Oana Teodora , Trifan Adriana , Puitel Adrian Catalin , Suteu Daniela
Published: August 2022

The valorization of indigenous flora waste by extraction of biologically active compounds has potential applications in the medical and cosmetic fields. The polyphenols and flavonoids extracted from this waste are valuable compounds for the manufacture of new cosmetic and/or dermato-cosmetic formulas to protect the skin from oxidative stress. This study obtained plant extracts from saffron waste—petals, tepals, and superior portions of stem—using different solid-liquid extraction techniques. The influence of some physical operating parameters was studied (extraction time, solid/liquid ratio, solvent extraction composition). The extraction method performance was assessed by the value of the extraction yields. The obtained extracts were characterized by the content of polyphenols and flavonoids, and the antioxidant activity determined with the DPPH and ABTS methods and the UV-VIS spectrometry. Some emulsions O/W were prepared and preliminarily characterized (pH, sensory analysis, stability after centrifugation and storage). The obtained results showed that the incorporation of this natural extract did not negatively affect the stability of the studied cosmetic formulations and advanced characterization (microbiological control of contamination, rheology studies and in vitro and in vivo studies) can be continued in order to implement a new product.
Halostability and thermostability of chitinase produced by fungi isolated from salt marsh soil in subtropical region of Saudi Arabia
Authors: Al Abboud Mohamed A. , Al-Rajhi Aisha M. H. , Shater Abdel-Rahman M. , Alawlaqi Mohamed M. , Mashraqi Abdullah , Selim Samy , Al Jaouni Soad K. , Abdel Ghany Tarek M.
Published: August 2022

Strategies based on halo- and thermostable enzymes are promising and attractive for biotechnological applications. Three fungal isolates, namely Aspergillus flavus, Cladosporium cladosporioides, and Alternaria alternata, and were subjected to chitinase production using a medium with different concentrations of NaCl up to 10%. C. cladosporioides was found to be the main chitinase producer at high concentration of NaCl; therefore, its identification was confirmed using 18S rDNA. The highest chitinase production (88.67 U/mL) was obtained by C. cladosporioides, followed by A. flavus (76.17 U/mL), and A. alternata (70.67 U/mL) at 5% NaCl, while their production without NaCl was 35.07 U/mL, 22.83 U/mL, and 21.33 U/mL, respectively. Thermal stability of chitinase was recorded at 50 °C at 20 min. Chitinase halostability at 20 min indicated that 10% NaCl was the optimum level, with activity 88.3 U/mL. Safranin dye decolorization by C. cladosporioides was enhanced to 88.25% via the addition of 5% NaCl to growth medium containing chitin. The inhibitory activity of chitinase was detected against C. lunata and F. oxysporium with or without NaCl. Culex pipiens larvae were more affected by C. cladosporioides chitinase produced at 5% than 10% NaCl. Energy scores of the molecular docking investigations confirmed the insecticidal activity of chitinase against C. pipiens larvae.
Characterization and adhesive performance of phenol-formaldehyde resol resin reinforced with carbon nanotubes
Authors: Ciritcioglu Hasan Hüseyin , Özbay Günay
Published: August 2022

Chemical, physical, thermal properties and bonding quality of phenol-formaldehyde resol resin (PF) synthesized with single-walled carbon nanotubes (SWCNTs) was evaluated at varying ratios from 1 wt% to 5 wt%. The effect of the SWCNTs addition on thermal and chemical properties of the PF resins was characterized by thermal gravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy, respectively. FT-IR analysis revealed that the peaks of the modified PF resol resins were similar to those of the reference (laboratory-produced) PF resol resin. These similarities indicated that the synthesis of the resins with phenol, formaldehyde, and carbon nano tubes was successful. The PF resins modified using SWCNTs demonstrated higher thermal stability than the reference PF resin. It was found that the bonding strength of the PF resin containing 3 wt% SWCNTs could reach 12.45 N/mm2 in dry conditions and 7.57 N/mm2 in wet conditions. The bonding test results demonstrated that the SWCNTs were able to improve the bonding performance of the resin under dry and/or wet conditions. This work presents an effective method to improve PF resins with SWCNTs reinforcement for use in the wood and/or polymer composite industries.
Bamboo Pleioblastus chino var. hisauchii characteristics before and after flowering
Authors: Cao Cong , Lv Huangfei , Yue Xianghua , Tian Genlin , Cao Rui , Zuo Lizhuan , Xie Fei , Xu Bin
Published: August 2022

Pleioblastus chino var. hisauchii is an important ornamental bamboo species that rarely flowers. Studies on the change in its material properties before and after flowering were lacking. In this paper, the anatomical, chemical, and mechanical properties of bamboo culms before and after flowering were studied by using the method of bio-wood science. The results showed that after flowering, the morphology and proportion of the fiber, vessel and vascular bundle decreased, and the openings of pits in the vessel wall were enlarged significantly; the contents of the main components such as extractives, lignin, holocellulose, cellulose and pentosan rose, while the ash content dropped. There was a decrease in density and modulus of rupture, and a pronounced fall in modulus of elasticity, while the microfibril angle and crystallinity increased. In general, the strength of bamboo flowering culms decreased and the ability to transport nutrients increased, which were closely related to the changes in internal structure and properties. This meant that bamboo flowering may be monitored or predicted by significant changes in some properties (such as pits and modulus of elasticity) and provide a reference for further research on the mechanism of flowering senescence and delayed flowering in bamboo.