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This study investigated the effect of various stacking sequences on the mechanical and acoustic characteristics of hemp and kenaf fibers reinforced hybrid composites. The mechanical study was done by using universal testing machine and izod imact tester. Further, acoustic study was done by using impendence tube method. Hemp/kenaf/kenaf/hemp hybrid laminates outperformed the other composites in terms of tensile strength, flexural strength and impact strength. In the mono reinforcements, hemp/epoxy composites demonstrated superior mechanical characteristics than the epoxy matrix and kenaf/epoxy composites. However, hybrid composites have superior mechanical behavior compared to pure composites. From the acoustic results revealed that the pure hemp and kenaf/hemp/hemp/kenaf hybrid composites exhibitted highest sound transmission loss level at lowest and highest frequency region. The bestmechanical characteristics of hybrid composites will be suggested for use in automobile door panels. Also, the optimal sound transmission coefficent values signifying their appropriateness for use in applications that encompass many frequency bands. Highlights: Hybridization of kenaf/hemp fibersImproved mechanical properties over the single fiber compositesBetter acoustic properties [ABSTRACT FROM AUTHOR]

• Hibiscus , a flowering plant (Malvaceae) renowned for medicinal and aesthetic value. • First in-depth report on the characterization of 19 different Hibiscus germplasms. • Revealed significant morphological, biochemical, and molecular diversity. • A multifaceted analysis of biochemical traits encompassing antioxidant properties. • Exhibited 34.75 % polymorphism among 19 Hibiscus germplasms using four molecular marker systems. Hibiscus , a popular ornamental plant of mallow family Malvaceae, is composed of more than 400 species of flowering plants. It is originally native to tropical Asia (China and India) and grows in warm-temperate, subtropical, and tropical regions worldwide. The basic chromosome number varies from x = 7, 8, 9, 11, 12, 15, 17, 19, 20 and 39. In ancient times, it was only used for religious purposes (as offerings to God), but nowadays, it is considered of great significance as an ornamental as well as a medicinal plant. Important species found in this zone are Hibiscus rosa-sinensis L., H. cannabinus L., H. storckii Seem., H. fragilis DC., H. schizopetalus (Mast.) Hooker. f. along with germplasms like Celia, Kali Jaba, Red Dragon, Cinnamon Girl, Brilliant, etc. have been identified to date. Still, there is a lack of proper documentation and characterization (based on morphological, biochemical, and molecular traits). With this aim in mind, the above research work was considered. On the basis of morphological parameters (plant height, flower weight, type of flower, etc.), Brilliant (T 1), Sudarshan Chakra (T 16), Storckii (T 15), and Golden Doublon (T 8) were similar but diverse from the rest of the germplasms. Likewise, Brilliant (T 1), Golden Doublon (T 8), Celia (T 2), and Versicolor Pinwheel (T 19) were rich in biochemical pigments viz., chlorophyll, carotenoid, lycopene, and anthocyanin content. In contrast, phenol and ascorbic acid were found to be highest in Spider (T 15), and antioxidant properties (DPPH and FRAP assay) were maximum in Oiseau Blue (T 12). Finally, a significant amount of genetic diversity was assessed with molecular markers, and 141 loci were produced using inter simple sequence repeats, start codon targeted, conserved DNA-derived polymorphism, and directed amplification of minisatellite-region DNA marker systems, out of which 49 loci were polymorphic (34.75 % polymorphism). On the basis of molecular diversity analyzed by network plot, unweighted pair group method with arithmetic mean clustering, and principal component analyses, Oiseau Blue (T 12) was found completely diverse from all the germplasms, placed separately in the dendrogram, and thus may be considered as a potential parent for the hybridization programme. [ABSTRACT FROM AUTHOR]

This study evaluates energy-economic (2-E) efficiency by reducing the glass cover temperatures and enhancing the condensation rates in solar desalination systems. This improvement is accomplished by incorporating natural kenaf fibers. The research introduces an innovative modification to a conventional solar desalination system (CSDS) by implementing a water-dripping mechanism using kenaf fibers positioned atop the glass cover. Experimental investigations were conducted on both the unmodified CSDS and the solar desalination system with kenaf fibers (SDSK) under analogous meteorological conditions to scrutinize the impact of natural fibers on freshwater production within an environmentally sustainable solar desalination paradigm. The integration of water dripping and fibers significantly led to a substantial reduction in glass temperatures, manifesting as a 30% decrease compared to the conventional CSDS. Furthermore, the distillate productivity of SDSK exhibited a remarkable enhancement of 48% relative to CSDS. Beyond its thermal performance, the cost per liter of potable water obtained from SDSK was determined to be ₹1.35, accompanied by a swift payback period of merely 3.9 months. In contrast, the corresponding figures for CSDS were ₹2.32 and 5.7 months, respectively. These findings underscore the advantages of incorporating kenaf fibers and water-dripping technology in solar desalination. This results in enhanced performance and cost-effective and expedited access to clean drinking water. [ABSTRACT FROM AUTHOR]

The current study focuses on exploring the effectiveness of Turtle Shell Powder (TSP) as a new and unique approach to use it as a filler material while fabricating kenaf/epoxy composites and investigating its potential application. The FRP composite of kenaf/epoxy reinforced with TSP filler was manufactured at various loading (1%, 3% and 5% by weight). The influence of TSP filled KFRP composite was studied and compared with the results of mechanical properties. SEM was employed to conduct morphological traits of the tensile fracture for the K0 and K5 samples with this EDAX also analysed. A notable enhancement observed from the result is the 5% TSP reinforced composite (K5) compared to other samples. This enhancement was ascribed to the improved dispersion and interfacial bonding between the reinforcement and the matrix in the composites, leading to more efficient load transfer mechanisms. The performance of TSP particles dramatically improves the strength of the laminated composites, and the inclusion of ply orientation further strengthens the interfacial bonding between TSP, epoxy and kenaf components. [ABSTRACT FROM AUTHOR]

BACKGROUND: Kenaf seeds are underutilized kenaf plant by‐products, containing essential nutrients including dietary fiber (DF), which can be potentially utilized as food ingredients. The present study aimed to evaluate the physicochemical characteristics of kenaf seed fiber fractions extracted from kenaf seed. RESULTS: Defatted kenaf seed powder yielded four DF fractions: alkali‐soluble hemicellulose (146.4 g kg−1), calcium‐bound pectin (10.3 g kg−1) and acid‐soluble pectin (25.4 g kg−1) made up the soluble fibre fraction, whereas cellulose (202.2 g kg−1) comprised the insoluble fraction. All fractions were evaluated for their physicochemical properties. The DF fractions contained glucose, mannose, xylose and arabinose, and a small amount of uronic acid (1.2–2.7 g kg−1). The isolated pectin fractions had a low degree of esterification (14–30%). All the isolated DF fractions had high average molecular weights ranging from 0.3 to 4.3 × 106 g mol−1. X‐ray diffractogram analysis revealed that the fractions consisted mainly of an amorphous structure with a relative crystallinity ranging from 31.6% to 44.1%. The Fourier‐transform infrared spectroscopy spectrum of kenaf seed and its DF fractions showed typical absorption of polysaccharides, with the presence of hydroxyl, carboxyl, acetyl and methyl groups. Scanning electron microscopy analysis demonstrated that the raw material with the rigid structure resulted in soluble and insoluble DF fractions with more fragile and fibrous appearances, respectively. The soluble DF demonstrated greater flowability and compressibility than the insoluble fractions. CONCLUSION: These findings provide novel information on the DF fractions of kenaf seeds, which could be used as a potential new DF for the food industry. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study explores the thermal and mechanical properties of a composite material formed by blending kenaf and basalt fibers with titanium oxide nanoparticles. To assess its performance under various conditions, we conducted thermogravimetric analysis (TGA) and hardness, sorptivity, and water absorption tests. During experimentation, composite samples were created using kenaf and basalt fibers as the reinforcing matrix and TiO2 nanoparticles as the modifier. Initial findings suggest that the addition of TiO2 nanoparticles enhances the mechanical properties and water resistance of the kenaf and basalt fiber composite. Samples reinforced with TiO2 demonstrated superior hardness and lower water absorption, i.e., KBT2 exhibited a hardness of 92 Hv and a water absorption rate of 6.4%. The value of 0.1% for KBT2 from the sorptivity investigation was promising, indicating its potential applicability in moisture-sensitive environments. In addition, TGA results show that KBT2 exhibited 0%, 2.1%, 4.7%, and 8.3% weight loss, showing improved thermal stability and high resilience to higher temperatures. In conclusion, the development of a novel material combining kenaf and basalt fibers reinforced with TiO2 nanoparticles presents a promising eco-friendly, durable, and lightweight option for engineering applications. Realizing the full potential of this composite material necessitates further characterization and optimization research. [ABSTRACT FROM AUTHOR]

• A total of 3439 DEGs were co-regulated by Cd treatment in cultivar 'F' and 'Z'. • Root cell wall polysaccharide provided protection against Cd and increased the Cd tolerance of kenaf. • Genes involved in antioxidant mechanism and Cd chelation, compartmentalization and efflux of root play key roles in kenaf Cd tolerance. • Cd uptake and transport could be mediated by HcZIP2 in kenaf. Kenaf is considered to have great potential for remediation of heavy metals in ecosystems. However, studies on molecular mechanisms of root Cd accumulation and tolerance are still inadequate. In this study, two differently tolerant kenaf cultivars were selected as materials and the physiological and transcriptomic effects were evaluated under Cd stress. This study showed that 200 µmol/L CdCl 2 treatment triggered the reactive oxygen species (ROS) explosion and membrane lipid peroxidation. Compared with the Cd-sensitive cultivar 'Z', the Cd-tolerant cultivar 'F' was able to resist oxidative stress in cells by producing higher antioxidant enzyme activities and increasing the contents of ascorbic acid (AsA) and glutathione (GSH). The root cell wall of 'F' exhibited higher polysaccharide contents under Cd treatment, providing more Cd-binding sites. There were 3,439 differentially expressed genes (DEGs) that were co-regulated by Cd treatment in two cultivars. Phenylpropanoid biosynthesis and plant hormone signal transduction pathways were significantly enriched by functional annotation analysis. DEGs associated with pectin, cellulose, and hemi-cellulose metabolism were involved in Cd chelation of root cell wall; V-ATPases, ABCC3 and Narmp3 could participated in vacuolar compartmentalization of Cd; PDR1 was responsible for Cd efflux; the organic acid transporters contributed to the absorption of Cd in soil. These genes might have played key roles in kenaf Cd tolerance and Cd accumulation. Moreover, HcZIP2 was identified to be involved in Cd uptake and transport in kenaf. Our findings provide a deeper understanding of the molecular pathways underlying Cd accumulation and detoxification mechanisms in kenaf. [Display omitted] [ABSTRACT FROM AUTHOR]

Indigenous micro-organisms often possess the ability to degrade petroleum hydrocarbon (PHC) in polluted soil. However, this process can be improved by supplementing with nutrients or the addition of more potent microbes. In this study, the ability of kenaf-core to stimulate the PHC degradation capability of microbial isolates from PHC polluted soil samples was evaluated. The standard experimental methods used in this study include: the digestion and analysis of the physico-chemical properties of petroleum hydrocarbon contaminated and non-contaminated soil samples; evaluation of petroleum hydrocarbon biodegradation using bio-augmentation and bio-stimulation (with kenaf-core) treatments; and, determination of soil microbial enzyme activities. Results from this study show that K, Na, total nitrogen, organic carbon, exchangeable cations, and heavy metals were found to be significantly (P < 0.05) higher in the polluted soil than in the non-polluted soil. Also, the polluted samples had pH values ranging from 5.5 to 6.0 while the non-polluted samples had a pH of 7.6. The microbial enzyme activities were comparatively lower in the polluted soils as compared to the non-polluted soil. The percentage degradation in the kenaf-core treated samples (AZ1T2—78.38; BN3T2—70.69; OL1T2—71.06; OT1T2—70.10) were significantly (P < 0.05) higher than those of the untreated (AZ1T1—13.50; BN3T1—12.50; OL1T1—10.55; OT1T1—9.50). The degradation of petroleum hydrocarbon in the bio-augmented and bio-stimulated treatments increased with increasing time of incubation, and were higher than that of the untreated sample. Comparatively, the treatment with a combination of kenaf-core and rhamnolipid exhibited a significantly (P < 0.05) higher degradation rate than that of the treatment with only kenaf core or rhamnolipid. While, the bio-stimulated and bio-augmented treatments had appreciable microbial counts that are higher than that of the untreated. In conclusion, the nutrient-supplement with kenaf-core significantly enhanced microbial growth and activities in the soil, thus improving their ability to biodegrade petroleum hydrocarbons in the polluted soils. Thus, supplementing with Kenaf core to encourage microbiological degradation of petroleum hydrocarbon is recommended. [ABSTRACT FROM AUTHOR]

Kenaf fiber is gaining prominence because of its ability as a natural-based reinforced material in advanced composites. However, kenaf contains a hygroscopic natural waxy substance that covers the fiber layer, providing a low surface tension and preventing strong bonding with the polymer matrix. The goal of this study is to optimize the blending parameters of kenaf fiber-reinforced epoxy composites by alkali treatment concentration, length, and fiber-matrix loading using central composite design. The maximum tensile strength was obtained at 6.03 wt% of NaOH concentration, fiber loading of 26.02 wt%, and fiber length at 7.39 mm, which showed a strong correlation between experimental and predicted values. The analysis of variance function model indicated that fiber length, sodium hydroxide concentration, and fiber loading all play important roles in mechanical properties of composites. Based on the fracture surface observations, kenaf fiber composite strength was closely related to bonding at fiber-matrix interfaces. The most common failure modes in the samples were voids, matrix fracture, fiber breakage, weak bonding, and fiber pull-out. [ABSTRACT FROM AUTHOR]

In the Malvaceae family, dynamic solar tracking by leaves is actuated by the deformation of the pulvinus, a thickened region at the leaf blade–petiole junction. While the internal structure is believed to play a crucial role in this process, experimental verification has been challenging due to technical limitations. To address this gap, we developed a semi-automated workflow, which integrates data analysis and image processing to simultaneously analyze the shape and internal structure of a Malvaceae pulvinus using X-ray microtomography. Firstly, we found that kenaf (Hibiscus cannabinus L.), a Malvaceae species with curved pulvini, exhibited solar-tracking leaf movement and selected it as a model system. We employed diffusible iodine-based contrast-enhanced computed tomography to visualize the internal structure of the kenaf pulvinus. Analysis of the pulvini's shape revealed variations in pulvinus morphology, yet plausible prediction of the centerline was accomplished using polar polynomial regression. Upon slicing the pulvini perpendicular to the centerline, we observed distinct gray value gradients along the proximo-distal and adaxial-abaxial axes, challenging threshold-based tissue segmentation. This workflow successfully generated three modified 3D images and derived quantitative parameters. Using these quantitative parameters, we conducted network analysis and found the linkage between the size-normalized cortex cross-sectional area and curvature. Polynomial least absolute shrinkage and selection operator (LASSO) regression revealed the relationship between the size-normalized cortex cross-sectional area and curvature commonly in all three tested samples. This workflow enables simultaneous analysis of the shape and internal structure, significantly improving the reproducibility of Malvaceae leaf pulvinus characterization. [ABSTRACT FROM AUTHOR]

In view of no reports on natural fiber reinforced functionalized styrene acrylonitrile composites, this study develops kenaf fiber (KNF) reinforced chemically functionalized styrene acrylonitrile (CF-SAN) composites (KNF/CF-SAN) by extrusion and injection molding. The selected CF-SAN matrix is a chemically functionalized random ter-polymer, with high (10 ± 2%) maleic anhydride functionality and requires higher processing temperature. With respect to CF-SAN, the 10/90, 20/80 and 30/70 KNF/CF-SAN composites show 25%, 46% and 75% higher tensile modulus, 23%, 55% and 78% higher tensile strength, 34%, 66% and 104% higher flexural modulus and 48%, 87% and 125% higher flexural strength. Relative to the dry matrix, the water absorbed composites show higher properties, but relative to the respective dry composites, the water absorbed composites have at least 7% lower tensile strength and at least 20% lower tensile modulus, flexural modulus and flexural strength. SEM and FTIR (ATR-IR) establish that hydrogen bonding and esterification by Palsule process impart CF-SAN/KNF adhesion and bonding in the composites. The composites show thermal stability between KNF reinforcement and CF-SAN matrix upto 295°C. [ABSTRACT FROM AUTHOR]

This study aims to investigate the tensile strength of the polypropylene-based bio-composites reinforced with natural kenaf fibers, basalt fiber, and nanographenes. The response surface methodology was used to investigate the behavior of the bio-composites based on the weight percentage of basalt and kenaf fibers and nanographenes. The behavior of the samples was analyzed using the tensile test, and the results were interpreted using field emission scanning electron microscope images. The fracture surface of the samples indicated the fibers' breakage and their separation as well as the pullout of the fibers from the substrate as the main mechanisms in improving the behavior of the bio-composite under study. Then, the multi-objective optimization was performed by increasing the tensile strength and elastic modulus and reducing the weight of the samples, and a Pareto diagram was drawn according to the design objectives. The results showed that the bio-composite sample in the optimal status with the maximum tensile strength of 30.9481 MPa and the lowest weight includes 15% kenaf fibers and 0.862% graphene nanoparticles. Moreover, the optimal sample of the bio-composite with the highest elastic modulus of 3.5126 GPa and the minimum weight of 1.626 g consists of 15% of kenaf fiber and 1.5% of graphene nanoparticles. Twenty-seven percent reduction in composite weight by optimizing the amount of reinforcements causes the weight of the final structure to be significantly reduced in the use of these composite plates in high volumes. [ABSTRACT FROM AUTHOR]

The purpose of this study is to determine how the gas cure pressure affects the Mode II interfacial brittle material behaviour of undergrad Kenaf fibre reinforced polymers. Ending-notch deformation experiments were used to examine the shifts in materials and geometric characteristics caused by the use of pressure on uni-directional kenaf samples. When the rigidity of several composite structures hardened at elevated pressure was investigated, it was discovered that both material and geometrical rigidity contributed to the strength of the laminate, although their contributions to overall rigidity varied. It is demonstrated that micro hardness levels, GIIC, are unchanged by rigidity because they are exclusively connected to the forces generated by the initiation and propagation of cracks. It is demonstrated that the depth of a character affects all attributes, particularly toughness. The relative shatter strength of composite material treated at 6 psi, 300 psi, and 700 psi varies. An optimal height of a core layer provides combined cohesive and adhesion barriers to fracture development, resulting in good fracture toughness. [ABSTRACT FROM AUTHOR]

Messor is a diverse genus of Myrmicinae with 168 extant species and subspecies. In the Mediterranean, some of its taxa historically were classified as members of the Messor instabilis group (sensu Santschi), of which 19 are known from the eastern Mediterranean. Here, the Messor semirufus complex of the Balkan Peninsula that assembles a distinct subsection of members of the instabilis group is defined and treated. In total, five species are recorded, including three that are new. Messor atanassovii Atanassov, 1982 is redescribed and confirmed for Bulgaria (Thracian Plain, Struma, and Mesta Valley, Pirin Mt., and Eastern Rhodopi) and Greece (Epirus, Ionian Islands, Central and Eastern Macedonia, and Thraki). Three species are described as new to science: Messor danaes Salata, Georgiadis & Borowiec, sp. nov. (Cyclades: Serifos), Messor kardamenae Salata & Borowiec, sp. nov. (Dodecanese: Kos, Nisyros, Rhodes, and Tilos), and Messor veneris Salata, Georgiadis & Borowiec, sp. nov. (Cyclades: Milos). The fifth member of the complex, Messor creticus Borowiec & Salata, 2019, maintains its status of Cretan endemic. [ABSTRACT FROM AUTHOR]

Aiming to ease the cutting of kenaf stalks via bionics, the bionic disc cutter was designed. The upper jaw of the Batocera horsfieldi was used as a bionic prototype. Further, to explore its dynamic performance, an indoor multi-stalk cutting experimental bench was used to simulate the field operation process. A three-factor and two-level interaction orthogonal experiment was carried out; cutting speed, stalk conveying speed (machine forward speed), and blade type (ordinary disc cutter and bionic disc cutter) were used as experiment factors. The cutting pass rate and cutting specific energy consumption were selected as evaluation indexes. The range, variance, and fuzzy comprehensive evaluation analysis were carried out on the experiment results. Moreover, the main order factors affecting the bionic cutter performance were determined-blade type, conveying speed, the interaction between the cutter speed and conveying speed, and cutter speed. The optimal parameter combination scheme had a cutter speed of 1000 r/min, conveying speed of 0.4 m/s, and included bionic blades. Under this condition, the best index was the 92% cutting pass rate, with a specific energy consumption of 4.38 J/stalk. The variance analysis has shown that, with 95% confidence, the blade type has a rather significant influence on the comprehensive index. Additionally, the conveying speed also significantly influenced it, while other factors and interactions had no notable effect. The experimental comparison under the same working condition shows that the bionic blade has better cutting effect. This study provides a reference for the development of cutter and the selection of kenaf harvester operational parameters. [ABSTRACT FROM AUTHOR]

Background: Flavonoids are one of the crucial secondary metabolites as several functions are carried out by flavonoids, including regulating cell growth, luring insects and pollinators, and defending against biotic and abiotic stressors. They are found in fruits, whole grains, vegetables, spices, tea, wine, herbs, and seeds. More than 4000 flavonoid compounds have been discovered and extracted through different techniques. Most flavonoids are frequently utilized in pharmaceuticals, nutraceuticals, cosmetics, and other products. A flavonol glucoside called gossypin is the primary phytochemical of herbs that comes under the "Malvaceae" family and can be found in many species, including Hibiscus esculentus, Gossypium indicum, and Hibiscus vitifolius, all have it in their flowers. Gossypin shows not only significant pharmacological activities but also a defence mechanism and protects against pathogens, UV radiation, etc. It has drawn much interest from researchers and scholars due to its benefits of few adverse effects, high efficacy, and simple preparation. Thus, the current review focuses primarily on the pharmacological accounts of gossypin in various acute and chronic diseases. The various assays and animal studies conducted in the past supported gossypin effects as supporting the concept of the objective of the title. The review also highlights various patents filled on gossypin's importance and current market scenario. Conclusion: Therefore, the technical contents based on pharmacological activities, patents and current market scenario provided in this paper for the improvement of research in numerous scientific fields will be helpful to researchers for suitable alternative designs of gossypin in various disorders. [ABSTRACT FROM AUTHOR]

Kenaf, also known as Deccan hemp (Hibiscus cannabinus L.) is the one of the most important, hardy and economic bast fiber industrial crops. Sulfur plays a significant role in determining yield and quality of fiber crops. However, the effect of sulfur application on yield, nutrient uptake in kenaf varieties, agronomic efficiency, apparent S recovery, and nutrient availability and sulfur fractions is still unclear. Thus, the present investigation was carried out to study the effect of sulfur (S) fertilization (S0= Control, S15=15kg S ha−1, S30=30kg S ha−1, S45=45kg S ha−1) on fiber yield, nutrient uptake, nutrient availability and S fractions of experimental soil and to screen the kenaf varieties ('JBM-2004-D', 'MT-150', 'AMC-108' and 'HC-583') for higher S use efficiency and increased productivity. Compared to control (S0), S45 treatment significantly increased fiber yield of kenaf by 37%. MT-150 produced the highest fiber yield (2.61 t ha−1). Among the S levels, S45 exhibited lowest value of agronomic efficiency (16.5 kg kg−1 S), apparent S recovery (18.7%) and highest value of nutrient uptake in kenaf. Results also revealed that nutrient availability (nitrogen, phosphorus and potassium) increased with increase in S levels at all soil depths and the nutrient status decreased with depth. Sulfur fractions (total S, organic S, adsorbed S, plant available S) increased with increasing S levels and followed the order as organic S > non-sulfate S > adsorbed S > plant available S. In addition, organic sulfur contributed 63–74% of total sulfur. Thus, the results suggest that by selecting appropriate variety and level of sulfur (@ 30 kg ha−1) for kenaf cultivation farmers can obtain higher fiber yield for sustainable crop production. [ABSTRACT FROM AUTHOR]

Kenaf fibers were added as a reinforcement between wood veneers of poplar (Populus deltoides) bonded with urea--formaldehyde (UF) resin to improve the applicational properties of standard three-layered plywood. Additionally, the influence of two different nanomaterials (nanocellulose and nanosilica)-modified UF resins on the performance of plywood was evaluated. Then, thickness swelling (TS), water absorption (WA), shear strength, and flexural properties were examined. Results indicated that reinforced composites with kenaf fibers improved the modulus of rupture (MOR) and modulus of elasticity (MOE) in both directions. In addition, physical properties, such as TS and WA after 24 h, improved in the reinforced plywood with kenaf and use of nanosilica (KNS) as a filler. The results of the mechanical properties were better than blanks. The treated adhesive, with nanocellulose and nanosilica revealed similar mechanical behaviors. The shear strength of plywood in KNC specimens showed the best result (increased 64.6% compared to blank) and MOR for both the parallel and perpendicular directions to the grain of the surface layers for KNS (105% and 158%, respectively), and MOE for KNS (92.9% and 152%, respectively) compared to the blank. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNC) were prepared from delignified kenaf bast fiber by using alkaline pulping, based on soda anthraquinone, hydrogen peroxide bleaching, and acid hydrolysis treatment with H2SO4. The size and morphology of the fibers were characterized by scanning electron microscopy (SEM), and the isolated fiber from unbleached and bleached pulp had a diameter between 9 to 30 µm. Fourier transform infrared (FTIR) spectroscopy exhibited that the content of lignin decreased in the pulping process, and the lignin was almost completely removed during hydrogen peroxide bleaching. Moreover, fibers were characterized for crystallinity using X-ray diffraction (XRD). The fiber crystallinity gradually increased at each stage of the process (raw kenaf bast, unbleached pulp, bleached pulp, and acid hydrolysis). The fiber was characterized by atomic force microscopy (AFM), which showed that the isolated pulp nanofibers had diameters of approximately 30 nm. [ABSTRACT FROM AUTHOR]

We present data on the taxonomic diversity and structure of macroinvertebrate communities in small, mostly 1st and 2nd order permanent streams from Struma, Mesta and Vardar watersheds (7th Ecoregion "Eastern Balkans") and analyse similarity in communities between/within studied basins. We reveal the characteristic elements of the macrozoobenthos from representative sites of R3- (mountainous) and R5- (semi-mountainous) river types. In total 69 samples from 38 sites were collected in autumn 2017 and spring 2018. The variation of the number of taxa, total abundance, relative abundance, species diversity and richness, evenness and index of dominance were analysed. A total of 280 taxa were recorded, and insects dominated the macroinvertebrate communities (> 70%). Overall, site similarities reflected the key macroinvertebrate metacommunities in R3- and R5-river type sections that provided higher β-diversity and lower similarities compared to the remainder of the watersheds. MDS- and dbRDA analyses separated the river basins by stream size and substratum heterogeneity. The highest α- and β-diversity were recorded within the Struma River watershed, which contributed to the higher γ-diversity and reflected the typical macroinvertebrate assemblages from the studied rivers of this Ecoregion. These results are important in application of management protocols especially when alike activities involve such river ecosystems. [ABSTRACT FROM AUTHOR]

This study presents an innovative approach utilizing Artificial Neural Network (ANN) strategies to evaluate the energy absorption capabilities of eco‐friendly rubber crumb/kenaf composites subjected to low‐velocity impact loads. The primary objectives of this research were to assess the energy absorption characteristics of these sustainable composites, understand their mechanical behavior under the impact, and provide valuable insights into their potential applications. To achieve these objectives, an experimental methodology was employed. Rubber crumb/kenaf composites with varying compositions were prepared, and low‐velocity impact tests were conducted using a drop‐weight impact testing apparatus to assess their energy absorption behavior and these parameters were used as inputs for training the ANN models. The weight percentage of waste tire rubber particle (WTRP), type of impactor and impact energies are considered as input data, whereas the absorbed energy is treated as the output. Through the advanced ANN strategies, accurate predictions of energy absorption performance were achieved for the rubber crumb/kenaf composites. The Levenberg–Marquardt optimisation algorithm with ten neurons and a tangent sigmoid activation function is used to train the ANN model. The trained ANN model is tested on an unseen dataset, different from the training data. It is shown to accurately predict the energy absorption characteristics of WTRP/KRE composites with a maximum error of 4.54%. The results revealed that the composite's energy absorption capabilities were influenced by the ratio of rubber crumb to kenaf, as well as the impact velocity. Additionally, the ANN models demonstrated excellent predictive capabilities, enabling efficient estimation of energy absorption behavior. The significance of these results lies in the potential applications of eco‐friendly rubber crumb/kenaf composites. By understanding their energy absorption characteristics, these composites can be effectively utilized in various industries. For instance, they could be employed in automotive parts manufacturing to enhance occupant safety during low‐velocity impact events. Furthermore, these composites can find applications in sports equipment, protective gear, and other impact‐prone products, contributing to sustainable and environmentally friendly materials. It is believed that by adopting the proposed ANN methodology, the experimentation costs and time can be significantly reduced without compromising the accuracy of the results. The obtained results provide valuable insights into the mechanical behavior of these sustainable composites and open avenues for their implementation in diverse industries where impact resistance is crucial Highlights: Development of sustainable Rubber crumb/kenaf compositesApplication of advanced ANN based predictive assessment of the impact responseParametric study of impactor shape and height of impact is performedThe damage mechanism contributing to energy absorption is micrographically studied [ABSTRACT FROM AUTHOR]

The green preparation of metal oxide nanoparticles is an environmentally friendly method, which could reduce the use of toxic solvents and their impact on the environment. The purpose of this study is to investigate the green synthesis of zinc oxide (ZnO) nanoparticles using extracts of Hibiscus cannabinus leaves and to evaluate their potential applications in environmental remediation. In this work, ZnO nanoparticles were successfully prepared and thoroughly characterized using UV–vis, Fourier transform infrared analysis (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM) analysis, and scanning electron microscope (SEM) with energy dispersive x-ray analysis (EDAX). As a result, the synthesized ZnO nanoparticles showed a good adsorption capacity for Congo red (CR), and satisfactory antioxidant and antibacterial activities. They exhibited good adsorption and removal abilities for CR in aqueous solutions. With the conditions optimized, the adsorption kinetics and isotherms were fitted to the pseudo-second-order model and the Langmuir model. The ZnO nanoparticles could also effectively scavenge 2-2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-di(3-ethylbenzthiazoline sulphonate) (ABTS) radicals, and appeared to inhibit the growth of Escherichia coli and Staphylococcus aureus bacteria. Based on the identified adsorption capacity, the green synthesized ZnO nanoparticles demonstrated their potential to be used in the removal of dyeing wastewater and in the further purification of water due to their antioxidant activity and antibacterial activity. [ABSTRACT FROM AUTHOR]

The purpose of this study is to determine how the gas cure pressure affects the Mode II interfacial brittle material behaviour of undergrad Kenaf fibre reinforced polymers. Ending-notch deformation experiments were used to examine the shifts in materials and geometric characteristics caused by the use of pressure on uni-directional kenaf samples. When the rigidity of several composite structures hardened at elevated pressure was investigated, it was discovered that both material and geometrical rigidity contributed to the strength of the laminate, although their contributions to overall rigidity varied. It is demonstrated that micro hardness levels, GIIC, are unchanged by rigidity because they are exclusively connected to the forces generated by the initiation and propagation of cracks. It is demonstrated that the depth of a character affects all attributes, particularly toughness. The relative shatter strength of composite material treated at 6 psi, 300 psi, and 700 psi varies. An optimal height of a core layer provides combined cohesive and adhesion barriers to fracture development, resulting in good fracture toughness. [ABSTRACT FROM AUTHOR]

Water pollution from synthetic dyes and oil spills has a significant impact on the environment and living species. Here, we developed a low-cost, environmentally friendly and easily biodegradable magnetic hybrid bio-sponge nanocomposite from renewable resources such as collagen and cellulose (Kenaf fibre cellulose–collagen, KFCC). We loaded it with magnetic bimetallic Fe3O4@TiO2 (BFT) NPs to produce a photocatalyst material (KFCC-BFT) for the treatment of colored wastewater as well as a sorbent for oil–water separation. The characterization of the bimetallic BFT NPs by XRD, HRTEM and VSM showed the deposition of TiO2 particles onto the surface of Fe3O4 with lattice interlayers spacing of 0.24 and 0.33 nm for Fe3O4 and TiO2, respectively with ferromagnetic property. The UV–vis diffuse reflectance spectra result indicated that the band gap energy of bio-sponges decreases with the increase of the bimetallic moiety. The photocatalytic efficiency of the as-prepared magnetic hybrid bio-sponge in the degradation of crystal violet dye was up to 91.2% under visible light conditions and 86.6% under direct sunlight exposure. Furthermore, the magnetic hybrid bio-sponge was used to separate motor oil from water (> 99%) and had a high oil sorption capacity of 46.1 g/g. Investigation of the recyclability and reusability performance for 9 cycles revealed that the bio-sponge had a high sorption capacity for up to 5 cycles. Our results suggest that the bio-polymer-supported BFT hybrid nanocomposite is a cost-effective and easily biodegradable photocatalyst and has great potential for real-field environmental remediation applications. [ABSTRACT FROM AUTHOR]

Natural fiber-reinforced polymer composites are presently receiving the attention of scholars and industrialists due to their specific properties, such as being naturally eco-friendly, biodegradable, economical, viable, available, and sustainable. The key problems associated with natural fiber polymer composites, including fiber/matrix compatibility, high moisture absorption, and, especially, thermal degradation in engineering plastics (high-temperature plastics), constitute the most critical thrust of this review. It is noted that at high temperatures, natural fibers degrade and this has adversely restricted their usage with only commodity thermoplastics having relatively low melting temperatures, such as polypropylene (PP) and polyethylene (PE). This review paper, therefore, provides valuable research highlights on utilizing and improving the mechanical and thermal properties of natural kenaf fibers as reinforcement in engineering polymer composites for high-temperature engineering applications using polymer matrices, such as polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), and polyphenylene ether (PPE). The initial and various chemical treatments of natural fibers, their effect on the thermal and performance properties of natural fiber engineering thermoplastic composites, and the advanced treatment of epoxy coatings are reviewed. Applications of natural fiber-reinforced thermoplastic composites in the construction and automotive industries, as well as in other applications, are outlined. It was established that the adhesion and thermal stabilities between polymer matrix and natural fibers are better improved by surface coating with diluted epoxy resin thermoset. This eventually improved the overall thermal and performance properties of the resultant composites and will serve as a data bank and guide for manufacturers and future research directions using high-end engineering polymers with higher processing temperatures. [ABSTRACT FROM AUTHOR]

The purpose of this study is to determine how the gas cure pressure affects the Mode II interfacial brittle material behaviour of undergrad Kenaf fibre reinforced polymers. Ending-notch deformation experiments were used to examine the shifts in materials and geometric characteristics caused by the use of pressure on uni-directional kenaf samples. When the rigidity of several composite structures hardened at elevated pressure was investigated, it was discovered that both material and geometrical rigidity contributed to the strength of the laminate, although their contributions to overall rigidity varied. It is demonstrated that micro hardness levels, GIIC, are unchanged by rigidity because they are exclusively connected to the forces generated by the initiation and propagation of cracks. It is demonstrated that the depth of a character affects all attributes, particularly toughness. The relative shatter strength of composite material treated at 6 psi, 300 psi, and 700 psi varies. An optimal height of a core layer provides combined cohesive and adhesion barriers to fracture development, resulting in good fracture toughness. [ABSTRACT FROM AUTHOR]

Biomass lignin can be used to produce vanillin through an oxidation process. Although its purity is high, the processing time and separation efficiency are not ideal. This research aims to produce vanillin directly from Kenaf stalks without separating the lignin first from the lignocellulosic biomass. This method is greener because it does not require the separation of cellulose and hemicellulose from the biomass, thus minimizing the use of acid and alkaline solutions and saving time. A high oxygen storage capacity and release capacity of ceria as an oxidation catalyst contribute to the reversable redox properties between Ce4+ and Ce3+ in ceria lattice. Cerium oxide nanostructures were synthesized using a hydrothermal method treated under alkaline NaOH, followed by drying at 120 °C for 16 h and calcining at different temperatures between 400 and 600 °C for the direct oxidation of Kenaf stalks to vanillin under microwave irradiation. The catalysts were characterized for their physicochemical properties using XRD, N2 adsorption–desorption isotherms and TEM. All synthesized CeO2 nanostructures showed the presence of diffraction peaks assigned to the presence of cubic fluorite. The N2 adsorption–desorption isotherms showed that all catalysts possess a Type IV isotherm, indicating a mesoporous structure. The TEM image shows the uniform shape of the CeO2 nanostructures, while HRTEM images show that the CeO2 nanostructures are single-crystalline in nature. All catalysts were tested for the direct oxidation of Kenaf stalks using H2O2 as the oxidizing agent in temperatures ranging from 160 to 180 °C for 10–30 min with 0.1–0.3 g catalyst loading under 100–500 W of microwave irradiation. The CeO2-Nps-400 catalyst produced the highest vanillin yields of 3.84% and 4.32% for the direct oxidation of Kenaf stalks and extraction of lignin from Kenaf stalks, respectively. Compared to our earlier study, the highest vanillin yields of 2.90% and 3.70% for direct biomass and extracted lignin were achieved using a Ce/MgO catalyst. [ABSTRACT FROM AUTHOR]

Kenaf is one of the most important natural cannabis plants. Molecular marker-assisted breeding is vital for accelerating the breeding process of kenaf. However, the number of kenaf markers is insufficient for molecular marker-assisted breeding. Using transcriptome sequencing data for salt-stressed kenaf plants, the number and distribution of simple sequence repeats (SSRs) and single nucleotide variations (SNVs) in the expressed sequences were determined. The objectives of this study were to elucidate the sequence variations in kenaf genes expressed in response to salt stress and to identify stable and dependable molecular markers. Primers were designed for SSR loci and then EST-SSR molecular markers were generated. The subsequent analyses revealed that 30.50% of the unigenes contained SSR motifs, most of which were single nucleotides followed by trinucleotides and dinucleotides. The unigenes containing SSRs were mostly associated with kenaf salt tolerance. Additionally, 10,483 SNVs were detected in contig sequences. Of the 3995 differentially expressed genes encoding interacting proteins, 1297 contained SSRs. Most of these genes were associated with metabolic pathways (e.g., 03000 transcription factors, B09132 signal transduction, and 04122 sulfur relay system). We designed 20 pairs of EST-SSR primers to genotype 30 kenaf varieties (lines), of which 9 primer pairs were ideal for genotyping (e.g., 1 highly polymorphic marker and 2 moderately polymorphic markers). The primer pairs designed for the EST-SSR markers in the kenaf genome may be useful SSR molecular markers for future research on kenaf. The verified polymorphic markers may be applicable to the molecular marker-assisted breeding of salt-tolerant kenaf varieties. [ABSTRACT FROM AUTHOR]

This study aimed to model carbon footprint, carbon dioxide sequestration, and emissions from kenaf cultivation as well as utilization of core and bast as biomaterials in the automotive industries and their environmental implications. It also considers the selection of suitable processing methods to improve the environmental performance of automotive parts. The data were obtained from three areas, and each area was divided into three cultivated sub areas for the carbon footprint model. Data regarding the conversion of kenaf to fibre when using kenaf high decorticator machines were provided from Kenaf Processing and Marketing Centre (CMPC) in Malaysia. The results showed that the total estimated quantity of carbon footprint of kenaf cultivation in the studied areas as well as the farms was about 0.750 tonne CO2/tonne. In addition, the total estimated quantity of carbon sequestration of automotive components in the studied states as well as the district was approximately 180,000 tonne CO2/tonne/hectare/year in addition to carbon sequestered by soil in hectare of cultivated kenaf. The practices of kenaf cultivation, processing, and utilization into automotive components is essential for the environment and will assist in the mitigation of climate change risks. [ABSTRACT FROM AUTHOR]