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Content of cannabinoids in clonally propagated industrial hemp

ABSTRACT Cannabis sativa L. is an extremely variable species. Even within the same cultivar plants can significantly differ in the content and profile of cannabinoids. Therefore, the best method for production of uniform plants and standardized raw material is vegetative propagation using clones. The aim of this study was to determine the content of cannabidiolic acid (CBDA), cannabidiol (CBD), Δ9-tetrahydrocannabinolic acid (Δ9-THCA), Δ9-tetrahydrocannabinol (Δ9-THC), cannabichromene (CBC), cannabigerol (CBG), and cannabinol (CBN) in clonally propagated plants of industrial hemp. One hundred and thirty-nine plants representing 17 different hemp genotypes were regenerated in vitro, hardened, and grown in a vegetation hall until harvest. Single plants of each accession were analyzed using high-performance liquid chromatography with UV/diode-array detection (HPLC-DAD/UV). The results revealed significant variability in the total cannabinoid content (0.55–5.18% in dry weight) among tested genotypes and within the Epsilon 68 cultivar. The highest content of total CBD (4.410%) was recorded for EPS/40 genotype, while the level of total Δ9-THC was below the allowed threshold (0.3%). Therefore, we can conclude that some clonally propagated plants provided reproducible hemp material as a potential source of cannabidiol. The results of this study will be useful for breeding and early selection of hemp genotypes.

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Failure Analysis of Plant Fibre-Reinforced Composite in Civil Building Materials Using Non-Destructive Testing Methods: Current and Future Trend

ABSTRACT Natural plant fiber-reinforced composite (NFC) has become a preferred component in modern-day civil building construction materials because it offers, among others, an environment-friendly solution without compromising stringent engineering requirements. Such green-based composites have exhibited noteworthy level of competitiveness comparable to that of the existing commercially available nongreen materials. Furthermore, NFC can also be tailored to align with the desired functional attributes. However, lack of comprehensive guidelines and recommended applications of suitable methods to assess composite failure of such novel NFC have raised significant concerns. This paper provides a comprehensive review of the latest developments in nondestructive testing (NDT) that can be applied to investigate into NFC failures. The study further explores alternative nondestructive testing methods and technologies exhibiting potential use in plant fiber composites studies, hence paving the way to future investigation trends. Precise characterization of defects and identification of damages in NFCs present a major challenge, demanding application of advanced nondestructive testing (NDT) methodologies accompanied with expert interpretation. Findings in this review can be applied to identify and explore new areas of research to analyze failure modes and fractures in NFC by applying NDT or by integrating NDT with other advanced technologies including machine learning.

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A Review of Recent Progress in Fabrication Methods and Applications of Polydimethylsiloxane Sponge

ABSTRACT Research on stretchable materials has gained momentum with the increasing commercialization of wearable and flexible devices. Among the materials used in stretchable electronics, polydimethylsiloxane (PDMS) is popular owing to its remarkable mechanical properties when subjected to deformation. Recent studies have shown that sponge-like porous PDMS is gaining attention, as it provides high surface area and strong absorption properties as well as facilitates mass transfer, making it ideal for use in electronics. This review primarily focuses on the production method and application of porous PDMS. The article describes the various processing methods used to produce porous PDMS, including 3D printing, gas foaming, and phase separation, each of which results in different characteristics. Thus, researchers can choose the most suitable method according to their desired application. Porous PDMS provides channels for mass transfer and strong absorption properties that enable addition of fillers such as carbon nanotubes (CNTs), graphene, and metal nanoparticles, which can further enhance the functionality of the material. In addition, the review covers applications according to the filler used, such as sensors using CNT, flexible electrodes using NiO/MnO2/CNT, and nanogenerators using ZnO. Choosing the right material for the filler is important for obtaining the desired characteristics as per its application.

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Analyzing the Effects of Plasma Treatment Process Parameters on Fading of Cotton Fabrics Dyed with Two-Color Mix Dyes Using Bayesian Regulated Neural Networks (BRNNs)

ABSTRACT This study used Bayesian Regulated Neural Networks (BRNN) with 10-fold cross-validation to accurately forecast fading effects of plasma treatment on cotton fabrics for a given set of parameters. By training six independent BRNN models, a reduction in model complexity and an enhancement in generalizability to unknown datasets were achieved. The input comprises plasma treatment parameters and color measurements of the cotton fabric before fading, while the output comprises color measurements after fading. The plasma treatment parameters included color depth, air (oxygen) concentration, water content and treatment time. Color measurements included CIE L*a*b*C*h and K/S values. Furthermore, 162 datasets derived from two-color mixed-dye cotton fabrics were utilized for training and testing. The outcomes revealed superior prediction performance of the BRNN compared to the Levenberg-Marquardt Neural Networks, with R2 values approaching 1 and 82.35% to 94.12% of the sample predictions lying within the acceptable color difference range. Through global sensitivity analysis, the impact of treatment parameters on fading effects was quantified, providing a scientific basis for parameter adjustment. This study not only elucidated the mechanism of plasma treatment-induced fading but also offers effective prediction tools for the intelligent and digital development of the fashion clothing fading domain.

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Process Optimization for Aqueous Ethanosolv Pretreatment of Coffee Husk Biomass Using Response Surface Methodology

ABSTRACT This study targeted to optimize process factors using response surface methodology and determining their effect on delignification and cellulose recovery. Optimization of pretreatment conditions with desirability value of 0.828 was done at temperature (A) 150°C, contact time (B) 2 h, and liquid-to-solid ratio (LSR) (C) 15 ml/g. The sample was soaked in an aqueous ethanol solution (48% ethanol). Chemical composition was determined to be 1.87 ± 0.20, 7.03 ± 0.99, 28.05 ± 0.27, 39.29 ± 3.39, and 23.77 ± 3.91 wt% for ash, extractives, lignin, hemicellulose, and cellulose, respectively. Experimental results were validated by comparing actual value with predicted value. The model was verified as the best for improving delignification and cellulose yield. Coefficient of determination (R 2), analysis of variance (ANOVA), response plots, and optimization nodes were used to examine the experimental results. The quadratic equation was used to test the model, and ANOVA was used to evaluate the model’s statistical performance and correctness. Temperature, interaction term (BC), and quadratic terms (A2, B2, and C2) showed significance, while contact time, LSR, and interaction terms (AC and AB) indicated insignificance for cellulose recovery. Temperature, contact time, interaction term (AB), and quadratic terms (B2 and C2) showed significance, but LSR, interaction terms (AC and BC), and quadratic term (A2) showed insignificance for delignification. Pretreatment efficacy for delignification (6.0%) and cellulose recovery (151.80%) were achieved at optimal conditions. The pretreatment method is able to produce cellulose-rich coffee husk residues.

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Influence of Hydroxyl-Terminated Hyperbranched Polymer and Coupling Agent on the Performance of SF/PLA Composites

ABSTRACT Herein, a hydroxyl-terminated hyperbranched polymer (HPN) with abundant terminal hydroxyl groups was employed to modify straw-plastic composites and studied the effect of HPN concentration on straw fiber reinforced polylactic acid (SF/PLA). Silane coupling agent (CA) was used to improve the interfacial compatibility between SF, HPN and PLA matrix. The mechanical strength, thermal properties and water resistance of different SF/PLA composites were tested and analyzed. When the concentration of HPN is 6%, the HPN-SF/PLA has the best mechanical strength index. HPN modification, CA modification and the combination of both have positive effect on improving mechanical performance. Compared with the UN-SF/PLA, the tensile, flexural and impact strength of HPN+CA-SF/PLA composites were increased by 24.7%,16.6% and 10.8%, respectively. The crystallinity of SF/PLA treated with HPN, CA, and their combination increased from 28% to 29.4%, 36.9%, and 42.3%, respectively. However, low melting point of HPN caused a decrease in the Tg, Tm, Tc, Td5% and Tdmax of SF/PLA. These characteristic temperatures can be enhanced by adding CA for co-modification. In addition, the three modified approach were able to enhance the water resistance of SF/PLA composites due to the reduction of the number of hydroxyl groups on the SF surface and the enhancement of the interfacial bonding properties.

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New Dimensions of Various Interlock Knitted Derivatives

ABSTRACT This study investigated the derivatives of interlock knitted structures by changing stitch type, location, and their percentage (%) on different performance properties. In the current study, 11 different interlock knit structures were developed by using multiple combinations of knit, tuck, and miss stitches and different types of testing, i.e., physical, mechanical, thermo-physiological comfort, tactile comfort, and dimensional properties, were performed and investigated. Analysis of variance (ANOVA) was performed to determine the statistical significance of structure on the properties. Based on the results, it was concluded that stitch type, percentage, and location have a prominent influence on the abovementioned properties of knit fabrics, which is also elaborated by interaction plots. The present research used a multi-response optimization technique, i.e., principal component analysis (PCA), to identify the best structure for industrial applications like uniforms, based on the optimization of abovementioned properties. Based on the results, it was suggested that a sample with an interlock cross relief structure was found to be the best in all aspects among all samples, followed by interlock pique and double tuck, which were ranked as 2nd and 3rd, respectively. This paper highlights the possible application of different interlock knitted structures according to end use for manufacturers.

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