bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of charring thickness of wood by residual strength analysis
Authors: Kim Min Ji , Kim Sejong , Kim Chul-ki , Shim Kug Bo
Published: February 2022

This study was conducted to propose an accurate measurement method of charred thickness in structural glued laminated timber (glulam) exposed to standardized fire temperature conditions for evaluation of the fire resistance of Japanese larch (Larix kaempferi) structural glulam. The compressive strength of the test piece collected from the structural glulam exposed to the standardized fire temperature for two hours was analyzed. The results showed that there was residual strength of 14% in the boundary area between sound and charred part. Therefore, the thickness of charred part should be calculated as approximately 4.5 mm less than what is measured visually. The cell wall thickness between sound-, boundary-, and charred-part exposed to high temperature was observed under a microscope. Higher temperature resulted in a thinner tracheid cell wall, and the radial tissue was broken down. The transformation of the boundary part of these microstructures progressed gradually until full carbonization of wood occurred. Based on compressive strength tests and microscopic observation in the boundary part of specimens exposed to high temperature, the current visual assessment of charred thickness measurement is safe in terms of structural aspect but not efficient in terms of wood utilization point of view due to exception of load carrying area of the member.
The effects of continuous press speed and conditioning time on the particleboard properties at industrial scale
Authors: Çamlıbel Osman , Aydın Murat
Published: February 2022

Effects of continuous press speed (580 and 600 mm/s) and conditioning time (0 and 72 h) on some physical and mechanical properties and formaldehyde content of particleboards were investigated. The 18 mm thick boards were manufactured using urea-formaldehyde, with a 50% pine, 40% oak wood, and 10% poplar biomass mixture of the wood materials. According to the results of the unconditioned samples, the density, modulus of rupture (MOR), moisture content (MC), thickness swelling (TS), and water absorption (WA) were increased 0.8%, 4.4%, 0.4%, 4.4%, and 5.5% when press speed increased from 580 to 600 mm/s, while thickness, modulus of elasticity (MOE), internal bond (IB), surface soundness (SS), and free formaldehyde (FF) were decreased 0.3%, 4.9%, 2.4%, 10.6%, and 21.1%, respectively. On the contrary to the results of unconditioned samples, MOE and SS were increased 1% and 1.4%, respectively, and WA was decreased 3.5% with the increase in press speed when samples were conditioned for 72 h. Free formaldehyde content was the most prominent parameter influenced by the increase in press speed both for the unconditioned and 72 h conditioned samples.
The mechanism of high butanol acetone ratio in ABE fermentation with fern root as substrate
Authors: Mao Bifei , Huang Wenjing , Zhang Caiying , Lan Haiyan , Zhu Li , Zhang Bingcong
Published: February 2022

The butanol acetone ratio (B/A ratio) is a critical index to evaluate the process of ABE fermentation. In this article, fern root starch with yeast extract added (FY) was used as substrate for ABE fermentation. The final B/A ratio in a 5 L anaerobic fermentor reached the highest levels of 3.42, which signified an increment of 41% compared with corn. The mechanisms for the high B/A ratio of FY substrate were as follows: 1) the weakened organic acid circuit resulted in decreased acetone synthesis; 2) the NADH level of butanol synthesis was high; 3) coA transferase activity was low and butanol dehydrogenase activity was high. The final butanol concentration and substrate utilization were examined in a 5 L anaerobic fermentor, and the results validated the feasibility of ABE fermentation with FY as substrate.
Effect of chemical steeping on yields of glucose and xylose from dilute acid hydrolysis of extract from oil palm trunk
Authors: Wong Lih Jiun , H’ng Paik San , Abdullah Luqman Chuah , Paridah Mohamad Tahir , Chin Kit Ling
Published: February 2022

The effectiveness of chemical steeping was examined as a novel pretreatment prior to hydrolysis to influence the extractable yield of glucose and xylose from oil palm trunk (OPT). The chemical steeping parameters were 0.2% sodium metabisulphite (w/v), 0.5% lactic acid (v/v), 26 ± 2 °C, and 1 h, followed by dilute acid hydrolysis (2%, 4%, and 6% of sulphuric acid (v/v); 115 °C, 120 °C, and 130 °C; 15 min, 30 min, and 60 min). For comparison, the glucose and xylose yield extracted from untreated OPT was also examined. Thermal analysis showed that the lactic acid and sodium metabisulphite successfully degraded the lignocellulose of OPT. The total extracted glucose and xylose yield was improved, and was approximately 2.5% to 28.8% higher than the yield extracted from non-pretreated OPT fines. RSM analysis showed that the 130 °C x 50 min x 2% was predicted as the optimum parameters for the extraction of glucose and xylose through chemically treated OPT, and followed the dilute acid hydrolysis process. Analysis of variance showed that the hydrolysis parameters were significant model terms for the glucose and xylose yield. In conclusion, chemical steeping was successful as a pretreatment to increase the extractable glucose and xylose yield from OPT.
A case study of wood thermoplastic composite filament for 3D printing
Authors: Tokdemir Veysel , Altun Suat
Published: February 2022

The 3D printing technology is a method of converting proposed complex geometric shapes into solid models. One of these methods is the FDM (fused deposition modeling) printing technology as a considerably affordable and the most commonly used method in the world. The purpose of this study is to obtain FDM 3D printer filaments that are as natural as possible, resembling wood and evoking the sensation of wood upon touching through deployment of bio-based plastics and additives. Polylactic acid (PLA) and bio thermoplastic polyurethane (TPU) were used as matrices, and lignin and Arboform, a lignin-based biomaterial, were used as additives. The characteristics of composites achieved through addition of 10% lignin and Arboform to matrices were identified by differential scanning calorimetry (DSC) thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the tensile test. The effects of some printing parameters on the mechanical characteristics were also determined. Lignin induced a decrease in mechanical characteristics for both PLA and TPU. Arboform, on the other hand, demonstrated good bonding with TPU and increased tensile strength. Production of flexible and sufficiently durable parts by means of 10% Arboform-containing TPU filaments was demonstrated.
Heat sealing evaluation and runnability issues of flexible paper materials in a vertical form fill seal packaging machine
Authors: Merabtene Mahdi , Tanninen Panu , Varis Juha , Leminen Ville
Published: February 2022

Vertical form fill seal machines are commonly used to form pouches. This paper aimed to optimize the sealing parameters and evaluate the runnability of flexible paper-based packaging materials with a polyethylene coating, differentiated by their grammages and thicknesses. This was done in comparison with a commercial plastic film, an oriented polypropylene and polyethylene laminate, using two different sealing jaw patterns in an industrial-scale vertical form fill seal machine. Based on the results obtained, the first observable seal was found at a sealing temperature of 90 °C for the paper-based material and a sealing temperature of 100 °C for thermoplastic film, both at a dwell time of 2 s. It was shown that the paper-based material had a larger sealing window, up to a sealing temperature of 220 °C, before the material started to turn brown, while the thermoplastic film shrank at a sealing temperature of 140 °C. Several peel and compression strength tests were performed to evaluate the flexible paper-based material. Furthermore, several hindering issues were observed in the paper-based material during the production runs. These included wrinkling, web buckling, friction in the forming tubes, pouches airtightness, etc. As such, recommendations for further investigations and future studies are given.
What to do with toxic, contaminated cellulose-based adsorbents
Authors: Hubbe Martin A.
Published: February 2022

This editorial considers the end fates of toxic materials, such as heavy metals, dyes, and synthetic organic compounds, which can be recovered from polluted water by using bio-based adsorbents. The point of the editorial is that insufficient research attention has been paid to the final fate of such contaminants. By contrast, much is known regarding factors affecting the adsorption capacities and rates of adsorption onto cellulose-based materials. Highly contaminated solutions are produced during the regeneration of biosorbent materials. Eutectic freeze crystallization potentially could be used to isolate relative pure compounds of heavy metals from such solutions. Alternatively, biochar can be prepared from cellulosic material in such a way as to achieve strong attachment to certain pollutants. Such biochar, after its use as an adsorbent, could be placed in the ground, where it can be expected to remain stable as sequestered carbon. A high ion exchange capacity of such biochar has potential to reduce the rates of leaching, which could otherwise lead to contamination of groundwater near to landfill sites. As shown by these examples, some promising answers to the final fate of contaminants may conform to a “circular economy” model, whereas other promising answers may conform to a “cradle-to-grave” viewpoint.
Influence of torrefaction on the heating values and energy densities of hardwood and softwood
Authors: Lin Lang-Dong , Tsai Meng-Jie , Chang Fang-Chih , Ko Chun-Han , Yang Bing-Yuan
Published: February 2022

Lumber manufacturing facilities generate large amounts of wood residues as a by-product of processing. In this study, the torrefaction characteristics of the Cryptomeria japonica and Acacia confusa residues were evaluated and compared to microcrystalline cellulose. The torrefied products also were analyzed. The results showed that the higher heating value (HHV) of the C. japonica and A. confusa residues increased to 5,993 and 5,576 kcal/kg after 20 min of torrefaction at 310 °C, which was higher than the microcrystalline cellulose (4,340 kcal/kg). The energy densification of the torrefied biomass could rise to 1.17 to 1.20 times higher than the raw biomass. The condensable gaseous product was an organic acid liquid. The liquid product consisted of some alkanes, alcohols, esters, and amides. The exothermic temperature would be reduced after torrefaction. Additionally, the thermal treatment of the biomass destroyed the cellulose crystals and reduced the cellulose crystallinity index. In order to reduce the usage of fossil fuels, the torrefied solid biomass could be mixed with coal in power plants directly.
Screening of highly efficient fungi for the degradation of lignocelluloses by ionic liquids-assisted cellulase
Authors: Hu Xiao-Mei , Dong Shi-Jia , Han Hui-Ying , Gao Yun-Fei , Zhang Bi-Xian
Published: February 2022

A successful conversion of lignocellulosic biomass into biofuel could be achieved through an ionic liquids (ILs)-pretreatment and an enzyme saccharification. In this study, the fungal strains with high cellulase productions were isolated and identified as Penicillium janthinellum FHH1 and P. oxalicum FLY4. A high cellulase production was obtained at pH 4.0 and 30 °C for P. janthinellum FHH1 with corn stalk and beef extract for 9 days and for P. janthinellum FHH1 with corn stalk and peptone for 7 days. A pH range between 4.0 to 6.0 and a temperature range from 55 °C to 60 °C were applicable for cellulase with high activities during hydrolysis. A high NaCl-stability and a relatively high ILs-stability were found for cellulase obtained from P. oxalicum FLY4. High yields of reducing sugar were obtained by enzymatic hydrolysis of the original corn stalk and ILs-pretreated corn stalk. P. oxalicum FLY4 has a great potential for ILs-assisted fungi in the degradation of lignocellulosic biomass into value-added products.
Effects of a plant-cushioning material containing tangerine oil on bruising and mould growth of banana (Kluai Hom Thong) and its potential reuse
Authors: Saengwong-ngam Ravinun , Matan Narumol , Matan Nirundorn
Published: February 2022

The objectives of this study were to investigate the effects of a plant-cushioning material containing tangerine oil in conserving the quality of a Kluai Hom Thong banana during transportation and storage. In addition, the reuse of the plant-cushioning material with and without tangerine oil for two, three, or four transportation and storage cycles was investigated. The results demonstrated that the plant-cushioning material with tangerine oil protected the Kluai Hom Thong banana from mould growth by 100% and it reduced the bruised areas on the banana peel by 80%. The tangerine oil vapour released from the plant-cushioning material might also affect the ripening of the banana, since the colour changed from green to yellow more quickly in the fruit that had been treated with tangerine oil compared to the control fruit. In addition, this intelligent cushioning material containing tangerine oil has great potential in reducing bruised areas, inhibiting mould and extending the quality of the banana during transportation and storage (14 days) for at least one time compared to the control (5 to 7 days). The reuse of the plant-cushioning material, at least up to four times with and without tangerine oil for the protection of the banana, showed great potential.
A method of hydrophobically modifying paper with a trace reagent
Authors: Zhou Jingjing , Gao Guowei , Li Yansheng , Wang Dongdong , Hu Jingfang , Song Yu , Chen Peng
Published: February 2022

It is of great importance to protect paper cultural relics, especially in terms of making them waterproof. One of the important ways to protect paper cultural relics is by hydrophobic modification treatment. However, most of the existing hydrophobic modification methods rely on a great deal of organic solvents, which poses greater risks to safety and pollution. In this work, a simple, green, and effective method for paper hydrophobic treatment was proposed and evaluated. The vapor of a fluorinated triethoxysilane was reacted with the active hydroxyl group on the paper in a closed space, which realized the hydrophobic modification of the paper in one step. The contact angle of the hydrophobic paper prepared by this method was 148.4° under optimal experimental conditions. In addition, this method did not damage the paper, based on the results of the scanning electron microscopy of the paper before and after hydrophobic treatment. The generality of this method was verified by using other substrates and hydrophobic reagents. This method is simple to operate and does not require the usage of a large amount of organic reagent. It is expected to receive widespread attention in the field of the protection of paper and wooden cultural relics.
Kinetic study of torrefied woody biomass via TGA using a single heating rate and the model-fitting method
Authors: Lee Chang-Goo , Kim Min-Ji , Eom Chang-Deuk
Published: February 2022

A model-fitting method at a single heating rate (10 °C·min-1) was used to investigate the thermal kinetic characteristics of torrefied woody biomass. The kinetic parameters were examined for pine, oak, and bamboo samples with the order of the reaction set ranging from 0.1 to 0.5 and 1.0. Based on the thermogravimetric, derivative thermogravimetric, and derivative2 thermogravimetric curves obtained, the ranges at which substantial hemicellulose and cellulose pyrolysis occurs were set as the analysis range, and the kinetic parameters of each species were analyzed. The activation energy and pre-exponential factor were obtained at these analytical ranges using two differential methods (Friedman and Chatterjee-Conard) and an integral method (Coats-Redfern). Although there were numerical differences between the results of the differential and integral methods, the thermal properties of each sample exhibited a consistent trend. Softwood was found to have the highest reactivity and intermolecular collisions per unit weight during thermal decomposition. In the case of the torrefied oak and torrefied bamboo, considering that the carbon content and fixed carbon content were approximately 24% to 25% higher than the softwood, it is appropriate to consider the thermal characteristics of each species for producing a solid fuel based on the application.
Predictive model of the modulus of elasticity in static bending (MOE) of larch wood based on gray relation analysis (GRA) and gene expression programming (GEP)
Authors: Cheng Liting , Zhao Peng , Di Yajing , Dai Jian , Wang Ziyi , Guo Xiaodong , Wang Wei
Published: February 2022

To accurately evaluate the modulus of elasticity in static bending (MOE) of wooden components in ancient timberwork buildings under the “minimum intervention principle,” the nondestructive testing of physical and mechanical properties were conducted on larch. Using moisture content (MC), density (ρ), the stress wave propagation velocity ( ), the modulus of elasticity in dynamic bending (Ed), the rotational resistance value of the drilling needle (fdrill), and the resistance value of the feeding needle (ffeed) as the main parameters, the correlation between several parameters and MOE was firstly calculated using the Gray Relation Analysis (GRA) and ranked according to the strength of the correlation. Six combinations were selected according to the ranking, and the Gene Expression Programming algorithm (GEP) was used to build models for predicting MOE. The results showed that the correlation between several parameters and MOE was good (between 0.5 and 0.8), and the prediction model established with combination 6 was the best, which indicated that the prediction model established based on GRA-GEP algorithm had a certain feasibility and effectiveness, and the combined effect of the six parameters to evaluate the MOE of wooden components of ancient buildings was better in the field inspection.
Preparation and characterization of nanocellulose coating modified by titanium dioxide
Authors: Zhang Yi , Yu Shengfei , Luo Wusheng
Published: February 2022

The hydrophilic character of cellulose nanowhiskers (CNWs) coating was changed by the use of TiO2 to modify CNWs, thus preparing TiO2/CNWs coating by a two-step method. Meanwhile, the effect of the additive amount and particle size of TiO2 on the surface structure and water contact angle (WCA) of the coatings was studied. The solid contents of the suspension were characterized by Fourier infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The TiO2/CNWs coating was characterized via scanning electron microscopy (SEM) and atomic force microscopy (AFM). Moreover, their wettability by water was revealed by the contact angle analyzer. The AFM and WCA analyses showed different additive amount and particle size of TiO2 have different effects on the surface structure and the WCA of the coatings. When the additive amount of TiO2 was 0.2 wt% and the particle size of TiO2 was 30 nm, the WCA and surface roughness (Rq) of the obtained TiO2/CNWs coating reached maximum values of 86.2° and 135nm, respectively. The TiO2 was relatively evenly distributed in the coating and the addition of TiO2 increased the crystallinity of CNWs from 79.67% to 84.89%. In addition, the FTIR and XPS analyses showed that TiO2 only physically dispersed in CNWs instead of having significant chemical reaction with CNWs.
Estimation of compression and shrinkage properties of Brazilian tropical timber through porosimetry analysis by mercury intrusion
Authors: Almeida Andréa de Souza , Criscuolo Gabriel , Arroyo Felipe Nascimento , Aquino Vinícius Borges de Moura , Silva Diogo Aparecido Lopes , Molina Júlio Cesar , Chahud Eduardo , Branco Luiz Antonio Melgaço Nunes , Christoforo André Luis , Lahr Francisco Antonio Rocco
Published: February 2022

Wood is a natural material with properties that are strongly influenced by anatomical characteristics, so studies that aim to correlate properties through empirical equations in search of simplification to obtain the values of their characteristics are essential. In this context, this work aims to generate multiple regression models to estimate the properties of shrinkage and compression parallel and normal to the grain of Brazilian tropical woods as a function of the values of porosity, density, and for both properties, with porosity being obtained by mercury intrusion porosimetry. As a result, the radial (RRT) and total tangential (RTT) shrinkage could be estimated through porosity. However, it was not possible to estimate them considering only density as an independent variable. All the models that were used were able to accurately estimate the modulus of resistance and modulus of elasticity values (fc,0, Ec,0, fc,90, and Ec,90).
Effect of pH on the formation of benzyl ester bonds between glucuronic acid and dehydrogenation polymer
Authors: Wang Xiong , Le Xi , Peng Wenyao , Ye Peiyao , An Junjian , Zhang Guangyan , Wang Peng , Xie Yimin
Published: February 2022

The effect of pH on the addition reaction of glucuronic acid to quinone methides generated in the synthesis of dehydrogenation polymer (DHP or artificial lignin) was investigated. The DHP-glucuronic acid complexes were formed during DHP polymerization catalyzed by a mixture of laccase, β-glucosidase, and O2 within the pH range 7 to 4 in the presence of coniferin as a precursor. The structure of the product and the content of benzyl ester bonds were characterized by Fourier transform infrared spectroscopy, solid-state cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance spectroscopy, ion chromatography, high performance liquid chromatography, and elemental analysis. The results showed that the pH of the reaction system had an important role in the formation of the benzyl ester bonds. Acidic conditions favored the reaction of quinone methide intermediates with carboxyl groups of glucuronic acid in the biosynthesis of DHP. However, weakly acidic conditions (pH 6) enhanced the reaction of quinone methide intermediates with glucose. In neutral conditions, the DHP-protein complex can be efficiently synthesized by the addition reaction of quinone methide intermediates with amino acids in protein.
Preparation of carbon quantum dots from corn straw and their application in Cu2+ detection
Authors: Yang Jiliang , Guo Zijiao , Yue Xiantian
Published: February 2022

Water-soluble carbon quantum dots were hydrothermally produced using corn straw as the starting material and nitric acid solution as solvent, then they were introduced as fluorescent probes for the detection of Cu2+. High-resolution transmission electron microscopy and X-ray diffraction showed that the carbon quantum dots were spherical amorphous particles with a diameter of 5 nm. The surface functional groups of carbon quantum dots were observed via Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy. A new approach for Cu2+ detection was designed using carbon quantum dots based on fluorescence quenching. Linear relationships between the fluorescence variation and the Cu2+ level (1 mg·L-1 to 20 mg·L-1 and 20 mg·L-1 to 500 mg·L-1) were obtained, with coefficients of determination of 0.9960 and 0.9923, respectively. The Cu2+ detection limit was 4.26 mg·L-1. The probable quenching principle between Cu2+ and the carbon quantum dots was attributed to charge transfer.
Transportation cost analysis on alternative wood feedstocks for manufacturing wood-plastic composites
Authors: Pokhrel Geeta , Kizha Anil Raj , Gardner Douglas J.
Published: February 2022

This study evaluated and analyzed transportation costs for manufacturing wood-plastic composites (WPCs) using wood flour and wood pellet feedstocks. The study area ranged from Maine (ME) to Massachusetts (MA) in the Northeast region of the United States (US). Wood mills in ME were the raw material providers, and the WPC manufacturers in ME and MA were the destinations. The methodologies included the Origin-Destination (OD) cost matrix feature in ArcGIS to find least-cost pathways from each facility to each destination; baseline scenarios based on trucking costs, travel distances, and wood feedstocks; and sensitivity analyses to study the effects of fluctuating input variables (travel distance, shipment weight, and shipping costs over distance) to the shipping costs by weight. Accordingly, the best and worst-case scenarios were identified. The OD-cost matrix showed that shipping feedstocks from southern ME required shorter travel distances than from other regions because of proximity. Transporting wood pellets in a truck would reduce shipping costs by at least 25% compared to wood flour. The shipping costs by weight were inversely related to the shipment weight. The shipment weight of wood pellets was higher than flour in a truck trailer with fixed volume. It is foreseen that the transportation of wood pellets as opposed to wood flour would be economical.
Beech wood thermally modified in the melt of polyethylene glycol
Authors: Reinprecht Ladislav , Repák Miroslav
Published: February 2022

Various techniques of wood thermal modification in air, liquids, or melts at temperatures above 160 °C improve its resistance to biological damage and water. In this experiment, the European beech (Fagus sylvatica L.) wood was held for 1 to 4 hours in the melt of polyethylene glycol 6000 (PEG 6000) and during a given time either heated at 100 °C or thermally modified at 190 or 210 °C. Its decay resistance improved – maximally at using the more intense modification mode 210 °C/4h – to Poria placenta by 60.3% and to Trametes versicolor by 62.8%. The soaking and volume swelling in water of the PEG-thermally treated beech wood usually was significantly reduced, after 336 h maximally by 60% and 34.6%, respectively. The presence of PEG during the thermal modification processes caused darkening of beech wood – a decoratively interesting and more pronounced effect than what occurs in traditional air-thermal modifications – at which the Eab* was also great from 13.1 to 52.6. However, since the mechanical properties of the PEG-thermally modified beech wood worsened – impact bending strength maximally by 34% and Brinell hardness maximally by 43.3% – its application for structural elements would be limited.
Characterization of a xyloglucananse in biodegradation of woody plant xyloglucan from Caldicellulosiruptor kronotskyensis
Authors: Shi Hao , Guo Jiannan , Yan Xing , Cui Ge , Tan Zhongbiao , Zhu Xiaoyan , Zhou Jia , He Shuai , Wang Tao , Li Xiangqian
Published: February 2022

The 2,835-bp open reading frame of ckxgl74A (Locus_tag CALKRO_RS04315) with a natural carbohydrate module (CBM3b) from thermophilic anaerobic microorganism Caldicellulosiruptor kronotskyensis encodes a calculated 104-kDa of GH74 xyloglucanase Ckxgl74A. The purified recombinant Ckxgl74A expressed in Escherichia coli BL21 (DE3) revealed its optimal pH of 4.5 and temperature of 80 °C. The Ckxgl74A was stable over a temperature no more than 70 °C and a pH range of 4.5 to 5.0. Kinetic experiments with xyloglucan as a substrate gave a Km of 2.29 ± 0.04 mg mL-1, Vmax of 22.98 ± 0.02 mol mg-1 min-1, and kcat of 66.98 ± 0.01 s-1. Its activity could be activated by Ca2+ approximately two folds, while being significantly inhibited by Cu2+. These results showed that Ckxgl74A could be utilized in acid condition and possessed a good thermostability.
Larch wood defect definition and microscopic inversion analysis using the ELM near-infrared spectrum optimization along with WOA–SVM
Authors: Pan Shen , Wang Keqi , Chen Jinhao , Zhang Yizhuo
Published: February 2022

Near-infrared spectroscopy is a mature non-destructive testing technique that can be applied effectively to identify and distinguish the structural characteristics of wood from a microscopic perspective. To accurately describe the morphology of wood panels on multiple scales and uncover the mechanisms determining the mechanical properties of wood, the present study was initiated by first defining four regions—the knot, fiber deviation, transition, and clear wood regions. On the surface of solid wood panels, and then a method was presented for inversing the microscopic morphology of larch wood panels based on near-infrared spectral feature extraction and modeling analysis. The experiments revealed that the combinatorial optimization conducted after the extreme learning machine feature band optimization can help effectively extract appropriate near-infrared feature wavelengths, reduce model dimension, and improve model applicability and accuracy. Therefore, the near-infrared models established based on the combination of the whale optimization algorithm and a support vector machine could accurately define and distinguish the four regions on the wood surfaces. Moreover, it was confirmed that the application of NIR spectral features along with the ELM–WOA–SVM algorithm can help optimize the traditional linear description that models the defect morphology as a cone to an accurate nonlinear description and to perform highly accurate nonlinear inversion of panel morphology.
Rapid preparation of a composite insulating block comprising waste expanded polystyrene (EPS) foam and rice straw
Authors: Dou Yuting , Bao Anhong , Sun Duhong , Niu Zenan
Published: February 2022

Due to the world’s decreasing energy supply, reducing the energy consumption of building envelopes has become an urgent issue with economic benefits. Rice straw is a generally available agricultural residue. The purpose of this study was to estimate the effects of rapid pretreatment methods and slaked lime on the molding of rice straw insulation blocks and to evaluate the effectiveness of integrating expanded polystyrene (EPS) particle waste with rice straw as building materials to reduce the energy loss in buildings. The pretreatment time was shortened from 6 h to 3 h by mechanical stirring combined with lye soaking. The molding of the insulation block could be improved by the hardening of slaked lime through contrast experiments and electron microscope scanning. Moreover, the influences of the mass ratio of slaked lime to rice straw (RSR) and the dosage of the EPS particles (ωEPS) on the dry apparent density and the thermal conductivity of the insulation blocks were studied. The results showed that the slaked lime would increase the dry apparent density and weight of the insulation block, but the EPS can effectively reduce this negative effect and keep the thermal conductivity of the insulation block below 0.049 W·m-1·K-1. Ultimately, the rapid pretreatment technology was determined to include lye soaking for 3 h and mechanical stirring for 5 min. The material matching ratio scheme was determined to have a ωEPS value of less than 3% and an RSR value equal to 1/7.5.
Quantifying the finest particles in dust fractions created during the sanding of untreated and thermally modified beech wood
Authors: Majka Jerzy , Sydor Maciej , Pędzik Marta , Antov Petar , Krišťák Ľuboš , Kminiak Richard , Kučerka Martin , Rogoziński Tomasz
Published: February 2022

This article deals with the fractionation of wood dust by sieve after sanding. Dust from untreated beechwood was compared to dust from thermally modified beechwood (at 200 °C for 3 h). The authors hypothesized that the thermal modification changes the particle size distributions of the dust sieve fractions and that all the dust sieve fractions contain the finest particles, which are suspendable in the air and are potentially respirable. To obtain dust for testing, both wood materials were sanded with P120 paper at a belt speed of 14.5 m/s and a pressure of 0.65 N/cm2. A set of sieves with aperture sizes of 25, 80, and 250 µm were used to separate the dust into sieve fractions with grain sizes less than 25 µm, 25 to 80 µm, 80 to 250 µm, and greater than 250 µm. The content of the finest particles in the fractions was measured via a laser particle sizer. Both dusts had similar particle size distributions. In addition, each investigated fraction of both dusts contained the finest particles, i.e., less than 10 µm. It follows that the laser analysis method may be necessary to correctly assess the occupational risk at a sanding.
Density and dimensional stability of a wood-polymer nano-composite from fast-growing wood
Authors: Rahayu Istie , Prihatini Esti , Maddu Akhiruddin , Kurniati Mersi , Darmawan Wayan
Published: February 2022

The characteristics of ganitri wood can be improved via wood impregnation. The objective of this research was to analyze the density and dimensional stability of a wood polymer nano-composite, i.e., impregnated ganitri wood with a mixture of melamine formaldehyde furfuryl alcohol and nano-SiO2. The results showed that the impregnation process improved the physical properties of the impregnated ganitri wood. Impregnation with 0.5% melamine-formaldehyde furfuryl alcohol (MFFA)-nano SiO2 had a significant effect on the density, weight percent gain, anti-swelling efficiency, bulking effect (BE), and water uptake (WU). Increased percentage of density and BE values after being treated by MFFA with 0.5% nano-SiO2 were 51.2% and 311.7%, respectively. The percentage decrease in WU was 47.5% (MFFA with 0.5% nano-SiO2). X-ray diffraction analysis verified a decrease in the crystallinity of the wood cellulose. The melamine formaldehyde furfuryl alcohol and nano-SiO2 polymers were found to cover the wood cell walls and lumens (based on scanning electron microscopy images). The formaldehyde emissions of the wood polymer nano-composite decreased. Therefore, it is possible to produce more environmentally friendly materials through wood polymer nano-composites.
Heterogeneity of thermomechanical and chemi-thermo-mechanical pulps described with distributions of an independent common bonding factor on particle level
Authors: Ferritsius Olof , Ferritsius Rita , Rundlöf Mats , Österling Sofia Reyier , Engberg Birgitta A.
Published: February 2022

Particles in mechanical pulp show a wide variety but are commonly described using averages and/or collective properties. The authors suggest using distributions of a common bonding factor, BIND (Bonding INDicator), for each particle. The BIND-distribution is based on factor analysis of particle diameter, wall thickness, and external fibrillation of several mechanical pulps measured in an optical analyser. A characteristic BIND-distribution is set in the primary refiner, depending on both wood and process conditions, and remains almost intact along the process. Double-disc refiners gave flatter distributions and lower amounts of fibres with extreme values than single-disc refiners. More refining increased the differences between fibres with low and high BIND. Hence, it is more difficult to develop fibres with lower BIND. Examples are given of how BIND-distributions may be used to assess energy efficiency, fractionation efficiency, and influence of raw material. Mill scale operations were studied for printing-grade thermomechanical pulp (TMP), and board-grade chemi-thermomechanical pulp (CTMP), both from spruce.
Metal chloride mediated efficient conversion of hydroxymethylfurfural (HMF) into long-chain levulinate ester
Authors: Jia Songyan , Wang Minchao , Ma Jiao , Liu Xiumei , Zhang Yajing , Xu Zhanwei
Published: February 2022

Levulinate esters are a class of promising alternative fuels derived from biomass. The synthesis of levulinate esters from carbohydrates generally undergoes a route with hydroxymethylfurfural as an intermediate product. The conversion of hydroxymethylfurfural is an intrinsic limiting step for the formation of levulinate esters from carbohydrates. Recent work focuses more on the synthesis of short-chain levulinate esters from biomass, but long-chain levulinate esters have superior properties as fuels. In this work, the synthesis of n-hexyl levulinate, a representative long-chain levulinate ester, was investigated with a series of metal chloride catalysts. Iron chloride (FeCl3) and copper chloride (CuCl2) were found to be the most effective amongst the tested catalysts. An n-hexyl levulinate yield of approximately 65% with 100% hydroxymethylfurfural conversion could be achieved at a temperature of 160 °C after 240 min. This system was also applied to the conversion of hydroxymethylfurfural and other hexanols such as 2-ethyl-1-butanol, cyclohexanol, 2-hexanol, and 3-hexanol. The catalyst in the system was reusable in a consecutive batch mode. Mechanistic study indicated that the production of levulinate ester from hydroxymethylfurfural probably went through levulinic acid as the intermediate.
Utilizing two-dimensional gas chromatography time of flight mass spectrometry (GCxGC ToFMS) to characterize volatile products from pyrolysis of living vegetation foliage
Authors: Moore Roderquita K. , Dietenberger Mark A. , Mann Doreen H. , Lebow Patricia K. , Weise David R.
Published: February 2022

Wildland fire can cause significant damage but is also a natural process that is key to the healthy functioning of many ecosystems worldwide. Primary fuels for a wildland fire are the dead foliage and small branches which accumulate as litter on the ground. A cone calorimeter was used to measure the various aspects of these fuels. A single sample of preignition gases from the live leaves of seven plant species were vacuum collected on quality filters and within super-chilled solvent mixtures. GC-TOFMS (1D) and GCxGC-TOFMS (2D) were used to characterize the “white” smoke emissions. The vegetation chemicals were separated into 4 categories: hydrocarbons (CH), oxygenated organics (CHO), unknown peaks (UNK), and organic non-metals (ONM). The multivariate paired Hotelling T2 test determined that the composition of the white smoke as described by the relative number of peaks in the four chemical groups differed significantly between 1D and 2D (Prob > F3,4 = 0.00004). In contrast, the relative peak area percentages in the four chemical groups did not differ between 1D and 2D (Prob > F3,4 = 0.1258). The Molecular Chemical Maps (MCMs) were used to identify chemical trends between the known and unknown chemicals in live oak and longleaf pine. Application of the 2D technique may provide more detailed information necessary to improve the numerical modeling of wildland fire behavior and emissions production.
Direct strain distribution and finite-element-analysis simulation of the bonding interface of bamboo laminated lumber with ultrasound-treated bamboo strips
Authors: Guan Mingjie , Huang Zhiwei
Published: February 2022

An ultrasonic cavitation treatment was used to increase the permeability of phenol formaldehyde resin adhesive on the surface of bamboo strips, and two-ply laminated bamboo lumber was manufactured. The strain distribution along the bamboo interface under stretching conditions was investigated using the digital image correlation technique. The effect of the ultrasonic treatment on the bamboo strips in terms of the shear strain of the laminated bamboo lumber was investigated, and a finite-element analysis for the bonding interface was carried out to evaluate whether the deformation measurement could predict the mechanical behavior differences of the laminated bamboo lumber. The digital image correlation and shear strength results show that the strain was lower in the bamboo bonding interface after ultrasonic treatment and the shear strength was enhanced due to the increased adhesive penetration. The digital image correlation measurement and finite-element analysis simulation both showed that stress was more concentrated, and the strain value and strain zone width was higher in the carbonized bamboo bonding interface than in the bleached bamboo bonding interface. The finite-element analysis results appeared to be in agreement with the digital image correlation test results.
Totally chlorine free (TCF) bleaching of wheat straw soda-anthraquinone (AQ) pulp with a low initial kappa number
Authors: Lin Benping , Liu Yanlan , Chen Qijie , Ma Lefan , Xu Jun
Published: February 2022

The totally chlorine free (TCF) bleaching was studied for wheat straw soda-anthraquinone (AQ) pulp with a low kappa number of 8.3 using the sequence of OQPO and OQPOPO. It was found that the oxygen delignification on wheat straw pulp was still effective despite its low initial kappa number. A delignification extent of 42% and an ISO brightness increase of 10.9% were achieved. In the OQPO sequence, an ISO brightness ceiling of 87.2% was achieved as the hydrogen peroxide (H2O2) charge was increased from 2% to 6% in the PO stage. In the OQPOPO sequence, 2% H2O2 was added in the second PO stage and the pulp brightness exceeded 88% with a total charge of 4% H2O2 in the POPO bleaching. Higher brightness values of 89.5% and 90.1% were obtained under the total charges of 6% and 8% H2O2, respectively. Compared to the OQPO sequence, the higher brightness and equal viscosity of the bleached pulps were obtained under the same total charge of H2O2 in the OQPOPO sequence. The bleached pulps with high ISO brightness values (greater than 88%) retained acceptable strength properties. A slight decrease of fiber length occurred as the bleaching sequences proceeded, while the fiber width and curl index somewhat increased.
Orientation of Teaching, Research, and External Engagement Activities of Academics in Mexico
Authors: Haydeé Estévez-Nenniger Etty , González-Bello Edgar Oswaldo , Valdés-Cuervo Angel Alberto , García-Meza Isabel María
Published: February 2022

Some results of the international survey Academic Profession in the Knowledge based Society (APKIS) applied in Mexico are presented. The orientation of the teaching, research, and external engagement activities, and the differentiating effect of some variables, was analyzed in a sample of 3,757 full-time academics of 116 Higher Education Institutions. Referencing the international surveys of 1992 and 2007, it was found that there are changes and continuities in the activities of Mexican academics. The type of institution variable has a generalized differentiating impact on the orientation of the activities.
Implementing the Personalised Learning Framework in University Studies: What Is It That Works?
Authors: Kontrimiene Simona , Venslovaite Vita , Alisauskiene Stefanija , Kaminskiene Lina , Rutkiene Ausra , O’Mahony Catherine , Lee Laura , Guðjónsdóttir Hafdís , Kristinsdóttir Jónína V. , Wozniczka Anna K.
Published: February 2022

Personalised learning embraces the elements of mutual ownership by learners and teachers, flexible content, tools and learning environments, targeted support, and data-driven reflection and decision making. The current study utilises a mix of instrumental case study (Stake, 1995) and deductive thematic analysis (Braun, Clarke & Terry, 2015; Terry et al., 2017) methods to explore the accounts of students of two teacher education study programmes at Vilnius University. The programmes were innovated to include practices of personalised learning in line with the framework developed by partners of the Erasmus+ Strategic Partnership Project INTERPEARL (Innovative Teacher Education through Personalised Learning). The results yielded three major themes which capture the successes and setbacks the students face, namely, personalisation in vivo: facilitation of growth as a would-be teacher; personalisation not manifest: what does not work; and personalisation in the making: the dos and don’ts.
Kontruksi Berita Politik Media Online di Tempo.co dan Sindonews.com
Authors: Waluyo Djati
Published: February 2022

The purpose of this research is to know the frame coverage of Reports made by Hary Tanoesudibjo to Polda Metro Jaya against Allan Nairn and Tirto.id in Online media Tempo.co and SIndonews.com. in this study using a framing analysis of the Zhondang Pan and Gerald m. Kosicki. This study refers to the theory of the Zhondang Pan and Gerald m. Kosicki, this theory is used to find out how the perspective used by media for selecting issues and writing the news. As for the data to be analyzed is the selected news and text study library. 1) element syntax tempo.co write a Press Council via the call sindonews.com to write criticism against tirto.id  2) the elements of the script tempo.co tirto.idsiding and allan nairin, sindonews.com favors to hary tanoe second thematic Element 3) media have a theme different but with one major theme 4) second rhetorical Element media alike stress the one great theme.

Tujuan dari penelitian ini untuk mengetahui frame pemberitaan yang tentang Laporan yang dilakukan oleh Hary Tanoesudibjo ke Polda Metro Jaya terhadap Allan Nairn dan Tirto.id di media Online Tempo.co dan SIndonews.com. Dalam penelitian ini menggunakan analisis framing Zhondang Pan dan Gerald M. Kosicki. Penelitian ini mengacu pada teori dari Zhondang Pan dan Gerald M. Kosicki, teori ini digunakan untuk mengetahui bagaimana persepektif yang digunakan oleh media untuk menyeleksi isu dan menulis berita. Adapun data yang dianalisis adalah teks berita yang diseleksi dan studi kepustakaan. 1) unsur sintaksis tempo.co menulis ajakan melalui jalur dewan pers sindonews.com menulis kecaman terhadap tirto.id 2) Unsur skrip tempo.co berpihak tirto.id dan allan nairin, sindonews.com berpihak kepada hary tanoe 3) Unsur tematik kedua media memiliki tema yang berbeda tetapi dengan satu tema besar 4) Unsur retoris kedua media sama-sama menekankan satu tema besar.
Eksistensi Stringer di Kota Bandung
Authors: Adidah Siti , Wibawa Darajat , Tresnawaty Betty
Published: February 2022

ABSTRAK

Penulisan ini bertujuan untuk mengetahui bagaimana praktik stringer dalam melaksanakan peliputan di Kota Bandung serta mengetahui bagaimana sikap stringer dalam memaknai profesinya. Metode penelitian menggunakan metode deskriptif kualitatif yang berusaha mendeskripsikan seluruh keadaan yang terjadi pada objek penelitian dengan menggunakan data dari hasil observasi serta wawancara bersama informan. Hasil penelitian menunjukan bahwa praktek stringer tidak hanya terjadi di daerah saja di kota besarpun praktek ini masih ditemukan. Meskipun dengan jumlah yang tidak banyak, di Kota Bandung sendiri terdapat 4-5 stringer yang masih aktif bekerja kepada kontributornya. Tugas dan peran stringer di lapangan sama seperti kontributor, hanya saja stringer tidak mendapatkan hak intelektual dalam pengakuan karya jurnalistiknya. Cara stringer memandang serta memaknai pekerjaannya menjadi bias, sebagian mereka menganggap sebagai hal positif namun sebagian lagi menganggap sebagai hal negatif. Menjadi seorang stringer dapat dijadikan kesempatan untuk mengasah kemampuan serta proses pembelajaran menjadi wartawan nantinya, namun pada prosesnya dilapangan menjadi seorang stringer akan banyak menemui permasalahan.Meskipun stringer banyak membantu kerja kontributor di lapangan, praktek mempekerjakan stringer telah menyalahi kode etik jurnalistik. 

Kata Kunci : Stringer; Kontributor; Peliputan; Televisi

 

ABSTRACT

This paper aims to find out how practice stringers in carrying out coverage in the city of Bandung and find out how stringer’s attitude in interpreting his profession. This research method uses a qualitative descriptive. Descriptive method that attempts to describe all the conditions that occur in the object of research using data from observations and interviews with informant. The result showed that stringer practice did not only occur in regions in the big cities, but this practice was still found. Although there are not many, in Bandung there are 4-5 stringers who are still actively working with their contributors. The duties and role of stringers in the field are the same as contributors, only stringers do not get intellectual rights in recognition of their journalistic work. The way stringers look and interpret their work becomes based, some of them consider it positive but some consider it negative. A Stringer can be used as an opportunity to hone skills and as a learning process to become a journalist later, but many problems that occur in the process of working stringers in the field. Although stringers help contributors work a lot in the field, on the other hand the practice of employing stringers has violated the journalistic code of ethics.

Keywords: Stringer; Contributor; Covering; Television.