Volume 19 Issue 3

Mechanical properties (tensile strength (TS), modulus of elasticity in tensile (MET), flexural strength (FS), modulus of elasticity (MOE)) of the material to be obtained depending on the production parameters in the production of high-density polyethylene (HDPE) wood-polymer composites with Scots pine wood flour additive were predicted using Artificial Neural Networks (ANN) model and without destructive testing. In the first stage of the study, an ANN model was developed using data from 56 different studies in the literature on the mechanical properties of wood polymer composites. In the second stage, in order to determine the reliability of the model, output values were estimated using input parameters that had not been used in training and testing of the model. Based on the same input parameters, test specimens were produced and mechanical tests were performed. The results obtained from the experiments and ANN model were compared by considering the mean absolute percentage error (MAPE) value. The coefficient of determination (R²) values obtained in the training and testing phase of the ANN models were all higher than 0.90. In this way, the mechanical properties of the wood polymer composite were successfully predicted by the ANN model. Because most of the MAPE values obtained from the mechanical tests were below 10%, the model was considered a reliable model.

The creep behavior of crushed sugarcane end-leaf (SEL) was studied, with consideration of different loading force, moisture content, and feeding amount. Statistical analysis software was used to develop and fit the regression data to a strain change law as a function of time. The four-element Burgers model was used. A further goal was to analyze the effect of different test conditions on the fitted creep characteristic parameters. The instantaneous elasticity coefficient E₀ was found to increase when the loading force increased; the value of delayed elasticity coefficient E₁ increased and the value of cohesion coefficient η₀ decreased when the feeding amount increased; the value of delayed elasticity coefficient E₁ and cohesion coefficient η₀ decreased when the moisture content was increased. Therefore, the loading force, moisture content, and feeding amount of crushed SEL all affected the creep capacity of crushed SEL in compression. The results can provide substantial theoretical reference for the silage production of crushed SEL.

The 3D reconstruction and virtual display of wooden furniture cultural relics were investigated using laser scanning and CT scanning techniques. The suitability of different 3D reconstruction techniques and virtual display approaches were considered. The experiments demonstrated that digital models obtained from both laser scanning and CT scanning can be integrated seamlessly into virtual environments created with 3DMAX for exhibition purposes. Additionally, post-processing software, such as PR or AE, can be utilized to synthesize virtual display video. The resulting images exhibit self-adaptation capabilities, with clear and undistorted 3D model and texture image. Moreover, other types of scanned models are suitable for 3D micro-scale model printing, although CT-based models tend to achieve higher printing accuracy compared to those generated by laser scanning technology. However, the precision of 3D printing model is contingent upon factors such as the precision of digital model, the type of printer, and the printing material.

Mixed integer linear programming (MILP) is known as a type of programming that can combine continuous variables, integer variables, and (0-1) variables in the same algorithm and generate fitting results for the data. Using this technique, it is possible to model and solve complex problems in many different fields such as economics, biology, engineering, etc. In the present study, a regional planning model was developed using MILP technique for the conversion of manure from dairy and beef cattle into biogas and electrical energy. For this regional planning study, considering the locations of future facilities, data on dairy and beef cattle in the Isparta province of Türkiye were used. According to the model written and solution outputs, to utilize all manure obtained from dairy and beef cattles in Isparta, 5 biogas plants with a total manure processing capacity of approximately 522,000 tons should be built in different districts. It is possible to produce a total of approximately 21,000,000 m³ of biogas and 38,500 MW of electricity per year in these biogas plants. This electrical energy obtained can meet 3.83% of the annual electricity consumption of Isparta province.

The quality detection of alfalfa hay is crucial for the development of animal husbandry. In this study, a method for quality detection of alfalfa hay based on the fusion of multisource information including near-infrared spectroscopy, image processing techniques, and electronic nose is proposed. After SG convolution smoothing, feature wavelengths were extracted using Competitive Adaptive Re-weighting Scheme and Successive Projections Algorithm from the spectral data. The image data were denoised using adaptive wavelet thresholding, and color and texture features were extracted using color histograms and random forest algorithms, respectively. Electronic nose data using principal component analysis was used for data dimensionality reduction. Support Vector Machine, Extreme Learning Machine, and Multi-Layer Perceptron were employed to establish quality detection models of alfalfa hay based on spectroscopy, image, gas information, and their combination, respectively. Experimental results demonstrate that the fusion of near-infrared spectroscopy, image data, and gas information effectively enhances the classification accuracy of the model. The accuracy of the test set reaches 100%, with root mean square error and determination coefficient values of 0.1728 and 0.9239, respectively, surpassing prediction models established solely on individual information. This study provides new insights into alfalfa hay quality detection.

Seven groups of uniaxial tensile experiments on wood plastic composites with a High Density Polyethylene (HDPE) matrix at different temperatures were completed in this paper. The test temperatures ranged from -60 °C to 60 °C, with a temperature difference of 20 °C for each group. All samples exhibited tensile brittle fracture. The test results showed that the tensile strength of the specimens decreased continuously with increasing temperature. Taking 0 °C as the reference temperature, the ultimate strength of the sample at -60 °C was 1.63 times that at 0 °C. When the temperature was 60 °C, this value was 0.41. Then, it can be calculated that the ratio of the strength of the sample at -60 °C to that at 60 °C was approximately 3.93, and the corresponding ratio of the elastic modulus was approximately 4.52. This shows that the mechanical properties of WPC are sensitive to changes in temperature. The variation coefficient of the average strength and elastic modulus of WPC for different specimens at different temperatures was less than 0.17, showing good stability due to the small dispersion of mechanical properties among different samples at any specific temperature.

This study explored the effect of raw material morphology on the properties of bamboo–plastic composites produced using hot-pressing. To provide a reference for reducing the production cost and improve the product properties of the composites, polylactic acid (PLA)-based bamboo–plastic composites were prepared using bamboo chips with a shaved morphology (BS) and fiber morphology (BF) and PLA as the matrix material, via hot-pressing. The properties of the bamboo–plastic composites formed with BS and BF chips were studied and compared with those of composites with conventional granular morphology (BM) and powder morphology (BP). The results showed that when the content of the bamboo chips was at 50% (the same below), the mechanical properties of the BF/PLA composites were remarkably better than those of the other PLA-based composites. However, the BF/PLA composites showed a high degree of hydrophilicity, with a water contact angle of 70.0° and a water absorption of 10.8% at 288 h. More holes could be seen in the BF/PLA composites using a scanning electron microscope. Among the four types of PLA-based composites, better melt fluidity was found only in the BF/PLA composites, and the melting index was 65.3 g/min.

Polyamidoamine epichlorohydrin (PAAE) is a permanent wet strength resin used in papermaking. When applied to paperboard, some amount of resin is retained in the sheet, and some is lost to the white water. The papermaker usually knows the amount of PAAE charged to the pulp but has no idea how much chemical is retained in the sheet. In addition, the influence of PAAE dosage, freeness, zeta potential, and pulp kappa number variability on PAAE retention is not well understood. Factorial design experiments using unbleached and bleached softwood (loblolly pine) kraft pulps were conducted to understand the factors that affect PAAE retention. The results revealed that PAAE retention, wet tear index, and tensile index not only depended on the PAAE charged of the pulp but also depended significantly on the pulp freeness. In lieu of freeness, zeta potential data can be used to predict PAAE retention. In addition, at similar freeness, bleached pulp has the highest retention of PAAE compared to low and high kappa unbleached kraft pulps. The results also suggest that lignin may have potential as a wet strength agent.

This study extracted Bambusa blumeana fiber using alkaline boiling and then applied double-roll pressing in order to develop it, explore the applications of its various parts, and improve its utilization potential. The results showed that the outer bamboo fibers are finer and straighter than the inner and middle fibers, and the fracture mode of the bamboo fibers is brittle. From the inside to the outside, the tensile strength of the fiber bundle gradually increases from the top to the bottom. Moreover, the tensile strength of the outside bamboo fiber is twice that of the inside, reaching a maximum of 982 MPa. The surface of the interior bamboo fiber is relatively smooth and can be used in textile and decorative fields. Compared with internal and central bamboo fiber, the outer fiber has higher thermal stability and higher crystallinity, which makes it more advantageous in the process of strengthening composite materials. Studying the structures of fibers from different parts of Bambusa blumeana can provide substantial scientific support for the differential applications of bamboo fibers.

This study focuses on the pretreatment and characterization of natural fibers from the bamboo shoot shell (BSS) of Phyllostachys heterocycla to determine their suitability as biorefining materials. The discarded bamboo shoot shell was used as a source of fibers, which were analyzed for their physical, chemical, and microstructure properties. Fourier transform infrared spectroscopy, X-ray diffraction spectra, and scanning electron microscopy confirmed that a mixture of sodium hydroxide immersion plus high-pressure steam treatment allowed the cellulose structure to be disrupted, providing more adsorption sites for cellulases. Gas chromatography mass spectrometry (GC-MS) also showed that the pretreatment exposed the internal structure of the fibers and that high-mass silicon compounds were present in the eluted solution. After adding the cellulase produced by Trichoderma viride and Aspergillus niger, the reducing sugar yield was increased by 268% and 251%, compared to unpretreated BSS fibers. This strategy may apply to many industries, especially biorefining and lignocellulose biotransformation technology.