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Drought and salt stress are two important environmental factors that significantly restrict plant growth and reproduction. Malate dehydrogenase is essential to life as it is engaged in numerous physiological processes in cells, particularly those related to abiotic stress reactions. However, a complete understanding of MDH family members in kenaf is not clear yet. In this study, subcellular localization analysis and a yeast transcriptional activation assay revealed that HcMDH1 was localized in chloroplasts but had no transcriptional activation activity. When exposed to salt or drought stress, yeast cells expressing the HcMDH1 gene exhibit an increased survival rate. Overexpression of HcMDH1 in Arabidopsis increased seed germination rate and root growth when transgenic lines were exposed to varying concentrations of mannitol and NaCl. Subsequent physiological studies revealed that transgenic lines had higher concentrations of soluble carbohydrates, proline, and chlorophyll and lower concentrations of malondialdehyde (MDA) and reactive oxygen species (ROS). Furthermore, inhibiting HcMDH1 in kenaf using virus-induced gene silencing (VIGS) decreased salt and drought tolerance due to elevated ROS and MDA levels. In these silenced lines, the expression of six essential genes engaged in stress-resistance and photosynthesis, namely HcGAPDH, HcGLYK, HcFBA, HcFBPase, HcPGA, and HcLSD, is significantly altered under salt and drought stress. In summary, HcMDH1 is a complex and positive regulatory gene that plays a key role in regulating chlorophyll content, antioxidant enzyme activity and osmotic regulation under salt and drought stress, which may have implications for kenaf transgenic breeding. Highlights: HcMDH1 is located in the chloroplasts and could be induced by salt and drought stresses. Expression of the HcMDH1 in yeast improved its survival rate under salt and drought conditions. HcMDH1 can improve salt and drought tolerance ability by changing antioxidant activity. Silencing HcMDH1 reduced salt and drought tolerance by altering the expression of some stress-responsive genes. [ABSTRACT FROM AUTHOR]

Kenaf (Hibiscus cannabinu) is a grass bast fiber crop that has the ability to tolerate and accumulate heavy metals, and it has been considered as a potential heavy metal accumulator and remediation plant. Nramp is a natural resistance-related macrophage, which plays an important role in the transport of divalent metal ions, plant growth and development, and abiotic stress. In this study, the Nramp gene family of kenaf was analyzed at the whole genome level. A total of 15 HcNramp genes were identified. They are distributed unevenly on chromosomes. Phylogenetic analysis classified 15 HcNramp proteins into 3 different subfamilies. All proteins share specific motif 4 and motif 6, and the genes belonging to the same subfamily are similar in structure and motif. The promoters are rich in hormone response, meristem expression, and environmental stress response elements. Under different treatments, the expression levels of HcNramp genes vary in different tissues, and most of them are expressed in roots first. These findings can provide a basis for understanding the potential role of the Nramp gene family in kenaf in response to cadmium (Cd) stress, and are of great significance for screening related Cd tolerance genes in kenaf. [ABSTRACT FROM AUTHOR]

Poly(butylene‐adipate‐co‐terephthalate) (PBAT)/Kenaf fiber composites was prepared by the melt processing technique with various compositions to investigate the general properties. While the Young's modulus of the composite was profoundly improved, the tensile strength and elongation at break exhibited a significant diminished with the incorporation of kenaf fibers due to the poor interfacial adhesion between PBAT and Kenaf fibers. The Halpin‐Tsai model was applied, and the similar behavior of Young's modulus for the composite as compared to experimental results was calculated. The micro‐voids and cavitation were clearly confirmed by morphological observation. Reactive compatibilization with HDI improved the compatibility between PBAT and Kenaf fibers, and the mechanical performance was significantly enhanced due to improved interfacial adhesion. The PBAT/Kenaf composites with a reactive compatibilization showed considerable improvement of storage modulus, G′ in terminal region as well. The stable thermal stability could be also beneficial for thermal processing technique. The addition of Kenaf fiber resulted in a liquid‐like behavior decreasing elasticity of the PBAT/Kenaf composites. The HDI had a profound effect on increasing elasticity with solid‐like behavior resulting in enhancing the G′ and η* of the PBAT/Kenaf fiber composites due to the improved interfacial adhesion as confirmed from the morphological observation. Highlights: Kenaf fiber has a great effect on improvement of the modulus for PBAT/Kenaf compositesThe optimized PBAT/Kenaf composite composition is 96/4 wt% ratio for the compositeHDI is found to be a good compatibilizer for PBAT and Kenaf fiberReactive compatibilization enhances the interfacial adhesion between PBAT and Kenaf fiberThe compatibilized PBAT/Kenaf composites have the better mechanical performance [ABSTRACT FROM AUTHOR]

AbstractThis study aims to evaluate the mechanical characteristics of Kenaf Textile Reinforced Concrete (KTRC) specimens to address the growing interest in sustainable construction materials. The research investigated various parameters, including modulus of rupture, total toughness, and toughness indices, while also exploring the impact of polypropylene (PP) chopped – fibre, the number of textile layers (3 and 5), and their arrangement (symmetric and asymmetric) on the mechanical properties of KTRC. The results demonstrated that Kenaf meshes could be used as natural and cost-effective reinforcement in TRC. Increasing the number of reinforcement layers significantly enhanced total energy absorption, and the combination of chopped fibre and Kenaf meshes contributed to maintaining the crack strength of the composites. The results of the three-layer specimens demonstrate that as the percentage of PP fibres increases from 0% to 0.5% and 1%, there is a noticeable increase in toughness compared to the reference samples. Specifically, the toughness of the samples increased by 978.6, 1381.1, and 1520.7, respectively. Eventually, the behavior of the specimens until the moment of complete rupture mostly depends on the number of layers in the thickness of the specimen. [ABSTRACT FROM AUTHOR]

Natural fiber reinforced composites (NFRC) are in great demand for sound absorption applications in various industries, such as automotive, aircraft, and building construction applications compared to synthetic composite materials. Though conventional sound-absorbing materials are used for passive control, natural fibers are more effective and economical for sound-absorption treatments. This paper presents the efforts made in the preparation of various NFRC made of flax, hemp, and kenaf fibers with epoxy as a matrix material. Also, the acoustic properties of the natural fiber-reinforced composites are studied by measuring the sound absorption coefficient (SAC). The experiments were conducted to measure the SAC of composite samples of different thicknesses by using the impedance tube method with the aid of Active Format Description 1001 (AFD 1001) software at frequencies ranging from about 200 to 1600 Hz. Moreover, the combined effects of various natural fiber composites were studied by conducting detailed experimentation. The experimental results show that the flax fiber composite possesses a higher SAC ranging from about 0.778 to 0.892 varying the test specimen thickness from 20 to 40 mm. From the results, the flax composite has a high sound absorption coefficient compared to hemp and kenaf composites. The optimization of Acoustic properties was carried out by using an Analysis of Variance and the influence of factors such as type of composite material and composite thickness on SAC was calculated. [ABSTRACT FROM AUTHOR]

Double emulsion (DE) has recently attracted attention due to its ability to encapsulate hydrophilic and hydrophobic substances and controlled release properties. However, food-grade DE is prone to destabilization due to its complex structure, which makes practical application in the industries difficult. This study investigates the stabilization of DE containing ethanolic kenaf leaf extract using different concentrations of Pickering emulsifier mixture (PEM). PEM consists of sodium caseinate, tween-20, and beta-cyclodextrin at the fixed ratio of 57.9:27.6:14.5% (w/w/w). Key parameters such as droplet size, polydispersity index, creaming index, encapsulation efficiency, and droplet morphology were monitored during 5-week storage at 25 °C. All DE samples remained phase-stable and exhibited increasing viscosity throughout the storage. The droplets displayed a spherical shape, and functional group assessment indicated changes in the molecular interactions after ultrasonic emulsification. DE stabilized by 2.5% and 4.0% (w/w) PEM consistently maintained droplet size and distribution, achieving encapsulation efficiency exceeding 98%. Specifically, DE with 4.0% (w/w) PEM exhibited excellent resistance to pH changes. In conclusion, PEM-stabilized DE remained stable for up to 5 weeks at 25 °C, which facilitates the beneficial uses of double emulsion in food, cosmetic, and medical applications. [ABSTRACT FROM AUTHOR]

Highlights Hybrid kenaf/glass fiber reinforced polymer composites have emerged as promising structural materials, garnering significant attention due to their unique blend of natural kenaf fibers and synthetic glass fibers. However, despite their potential, there remains a gap in the comprehensive understanding of their quasi‐static mechanical behavior, creep resistance, and fatigue performance. This paper addresses this gap by presenting recent advancements in studying these key properties of hybrid composites. Studies reveal that the combination of kenaf and glass fibers results in enhanced tensile, flexural, and impact strengths compared to individual fiber composites. Additionally, the hybridization offers improved creep resistance, with the glass fibers reinforcing the polymer matrix against deformation under sustained loads. Furthermore, investigations into fatigue properties demonstrate the resilience of hybrid composites to cyclic loading, contributing to prolonged service life in high‐stress environments. By elucidating the interplay between kenaf and glass fibers, this review underscores the potential of hybrid composites in various structural applications. The synergistic effects between natural and synthetic fibers offer a balance between sustainability, performance, and durability, making hybrid kenaf/glass fiber reinforced polymer composites a compelling choice for industries seeking lightweight, high‐performance materials in which aligns with the sustainable development goals (SDGs) especially on Goal 12. In composite engineering, combining glass and kenaf fibers could cut production costs, yield high‐performance materials, and promote green technology. Substituting part of the glass fiber with kenaf can enhance the strength‐to‐weight ratio and promote greater biodegradability in current synthetic composites. Quasi‐mechanical properties of hybrid kenaf/glass‐based composites was enhanced by optimal stacking sequences, filler addition, and fiber treatment. Failures due to fatigue and creep can be reduced by hybridizing kenaf/glass fiber composites can prevent in polymer composite due to enhance elastic modulus. Enhanced tribological performance of hybrid kenaf/glass‐based composites due to less damage in microstructure via good interlocking of kenaf and glass in matrix. [ABSTRACT FROM AUTHOR]

The rapid advancement of polymer composites, particularly those reinforced with hybrid kenaf, has positioned them as viable structural materials across diverse industries such as automotive, defense, aerospace, marine, construction, and naval. Despite their growing popularity, recent advances in kenaf yarn‐reinforced thermoplastic acrylonitrile butadiene styrene (ABS) composites for structural applications need more comprehensive coverage in the literature. This article addresses this gap by critically examining the influence of quasi‐isotropic stacking orientation on water absorption, flexural strength, and impact properties in kenaf yarn fiber‐reinforced ABS composites. Prepared using hand layup and compression molding techniques, the composites featured varying stacking orientations, including 0°/0°/0°/0°, 0°/90°/0°/90°, −45°/90°/0°/45°, 90°/−45°/0°/45°, 90°/0°/45°/−45°, and 0°/45°/−45°/90° for kenaf yarn reinforced ABS. The findings reveal that the 0°/45°/−45°/90° configuration offers the best overall mechanical properties and water penetration resistance among quasi‐isotropic stacking sequences, exhibiting low water uptake and higher tensile and flexural strengths of 35.3 and 85.4 MPa, respectively, compared to other sequences. This suggests that incorporating ±45° plies contributes to a balanced distribution of mechanical strength and modulus across different directions, making the 0°/45°/−45°/90° configuration ideal for high‐strength structural applications in kenaf yarn/ABS composites. Highlights: Fiber stacking orientation is the key factor affecting the mechanical performance of kenaf‐based composites.Using the hand layup technique, six stacking orientations (0°/0°/0°/0°, 0°/90°/0°/90°, −45°/90°/0°/45°, 90°/−45°/0°/45°, 90°/0°/45°/−45°, and 0°/45°/−45°/90°) were employed to create kenaf fiber‐reinforced ABS composites.A quasi‐isotropic sequence of 0°/45°/−45°/90° allows the least water penetration due to the strategic placement of ±45° plies in the middle layers of composites.0°/45°/−45°/90° configuration offers the best flexural and tensile properties due to better force distribution within the ±45° plies in the middle layers.Under surface morphological analysis, the optimal fiber stacking sequence contributes to fewer voids and fiber pull‐outs. [ABSTRACT FROM AUTHOR]

Hibiscus cannabinus (kenaf) is an annual fiber crop grown in warm seasons and known for its remarkable productivity; it has been cultivated worldwide for thousands of years as a fiber source. While every part of the plant can be utilized for some purpose, its primary significance lies in the diverse applications of its cellulosic fiber. Kenaf features a blend of long bast and short core fibers, rendering it suitable for various industrial uses. Initially utilized for cordage and livestock feed, kenaf's applications have expanded over the last century to encompass its utilization as paper pulp, biocomposites, textiles, biomass energy, seed oil, filtration aids, industrial absorbents, and even as a component of potting medium or as a potential source of medicine. Although traditionally a niche crop, the discovery of its diverse applications positions kenaf for rapid expansion in production in the upcoming decades. This article aims to explore the manifold applications of kenaf, highlighting those with the greatest future potential and discussing those that hold promise for commercial-level application with additional research. [ABSTRACT FROM AUTHOR]

Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research focuses on the development and mechanical characterization of a lightweight sustainable fiber metal laminate (FML) using jute, kenaf, and aluminium. The objective is to investigate the feasibility of utilizing natural fiber composites in combination with aluminium to create a sustainable and lightweight material for various engineering applications. The mechanical behavior of metal laminates reinforced with jute and kenaf, with fiber concentrations ranging from 10% to 50%, is evaluated in this work. FMLs were fabricated using composite in the place of core and skin made up of metal. The mechanical behaviour of the developed FMLs was evaluated when they were subjected to tensile, flexural, and impact loading. The results showed that when the fiber percentage was set at 30 wt%, both jute and kenaf-based FMLs exhibited the best mechanical properties. Furthermore, kenaf-based FMLs (KFML) outperformed jute-based FMLs (JFML) in terms of mechanical properties. KFMLs had tensile and flexural strengths that were 4.76 and 10.2 percent higher than those of JFMLs with 30 weight percent fiber content. Kenaf-based FMLs exhibited an impact strength that was 8.19% more than that of jute-based FMLs. [ABSTRACT FROM AUTHOR]

In dynamic applications, the effective use of kenaf composite materials necessitates comprehensive and precise elucidation of their mechanical response under high strain rate loading conditions. Accurately measuring the sample’s deformation can only be achieved using a pulse-trapping technique. In this study, a dynamic momentum trapping mechanism that is simple to assemble and configure was constructed and affixed to a conventional Split Hopkinson Pressure Bar (SHPB) system. The effectiveness of the verified momentum trap approach was shown when the secondary wave of compression was decreased by 50 percent in the application of momentum trapping that stopped the specimen from coming in contact with the incident bar, resulting in a much-improved correlation between various strain rates and the failure of kenaf composite microstructure. [ABSTRACT FROM AUTHOR]

Abstract Extraction of lignin via green methods is a crucial step in promoting the bioconversion of lignocellulosic biomasses. In the present study, utilisation of natural deep eutectic solvent for the pretreatment of kenaf fibres biomass is performed. Furthermore, extracted lignin from natural deep eutectic solvent pretreated kenaf biomass was carried out and its comparative study with commercial lignin was studied. The extracted lignin was characterized and investigated through Infrared Fourier transform spectroscopy, X-ray Diffraction, thermogravimetric analysis, UV–Vis spectroscopy, and scanning electron microscopy. FTIR Spectra shows that all samples have almost same set of absorption bands with slight difference in frequencies. CHNS analysis of natural deep eutectic solvent pretreated kenaf fibre showed a slight increase in carbon % from 42.36 to 43.17% and an increase in nitrogen % from − 0.0939 to − 0.1377%. Morphological analysis of commercial lignin shows irregular/uneven surfaces whereas natural deep eutectic solvent extracted lignin shows smooth and wavy surface. EDX analysis indicated noticeable peaks for oxygen and carbon elements which are present in lignocellulosic biomass. Thermal properties showed that lignin is constant at higher temperatures due to more branching and production of extremely condensed aromatic structures. In UV–VIS spectroscopy, commercial lignin shows slightly broad peak between 300 and 400 nm due to presence of carbonyl bond whereas, natural deep eutectic solvent extracted lignin does not show up any peak in this range. XRD results showed that the crystallinity index percentage for kenaf and natural deep eutectic solvent treated kenaf was 70.33 and 69.5% respectively. Therefore, these innovative solvents will undoubtedly have significant impact on the development of clean, green, and sustainable products for biocatalysts, extraction, electrochemistry, adsorption applications.

This research investigates the effect of kenaf/carbon fiber reinforcement with the addition of nanofillers such as multi-walled carbon nanotubes (MWCNT) and cellulose nanocrystal (CNC) in the phenolic matrix composite. Three different types of samples were made using short carbon fiber, kenaf fiber (KF), BaSO4, Cashew dust, MWCNT, and CNC. Sample 1 contains 40 wt% of carbon fiber with binders reinforced in the phenolic matrix, whereas, in sample 2, carbon fiber has been replaced with KF in the MWCNT-modified phenolic matrix. On the other hand, in sample 3, carbon fiber has been replaced with KF in a CNC-modified phenolic matrix. The physical, mechanical, and tribological properties were investigated and compared. The results showed that sample 1 exhibited higher mechanical performance compared to other samples. On the other hand, the least wear loss and a high coefficient of friction were observed for Sample 2 compared to Samples 1 and 3. Even though KF-based composites exhibited slightly lower mechanical performance, they showed excellent tribological behavior.

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]

The aim of this research article is to develop a mathematical model of the impact cutting behaviour of a circular cutting blade on kenaf stems. The model predicts and validates the effects of crop maturity and varieties on the cutting torque, power, and energy required during kenaf harvesting. The developed mathematical model for predicting the cutting torque, power, and energy for an improved tractor mounted kenaf harvester was found to be accurate. The cutting torque, power, and energy consumed during kenaf harvesting increase steadily with increased maturity for all varieties of kenaf. Also, the highest cutting torque, power, and energy during the harvesting of Ifeken 400 ranged from 1.51 Nm to 3.36 Nm, 10.19 kW to 22.61 kW, and 1.77 Joules to 3.94 Joules. [ABSTRACT FROM AUTHOR]

This study compared kenaf-based solid fuel characteristics using three processes: hydrothermal carbonization (HTC), torrefaction (TOR), and low-ash TOR, (LA_TOR). Solid fuels were produced by conducting the ash removal process at 50 °C for 60 min in an autoclave, followed by HTC or TOR at various temperatures (160, 200, 240, 280, and 320 °C) for 60 min. The resulting products' chemical compositions and fuel properties were then compared. The study found that under HTC at 320 °C, the product had the highest carbon content compared with the products from TOR and LA_TOR at 320 °C. Thus, HTC produced the highest-quality solid fuel of the three methods. However, this process showed a low energy yield and significant energy loss. In contrast, LA_TOR exhibited a high energy yield, low energy loss, and effectively reduced the ash content of the product. This demonstrates its suitability for industrial-scale applications that demand fuel with low ash content and energy loss. [ABSTRACT FROM AUTHOR]

The present work emphasizes the isolation of cellulose nanofiber (CNF) from the kenaf (Hibiscus cannabinus) bast through a chemo-mechanical process. In order to develop high CNF yield with superior properties of CNF for improving compatibility in varied applications this method is proposed. The fiber purification involved pulping and bleaching treatments, whereas mechanical treatment was performed by grinding and high-pressure treatments. The kraft pulping as a delignification method followed by bleaching has successfully removed almost 99% lignin in the fiber with high pulp yield and delignification selectivity. The morphology of the fibers was characterized by scanning electron microscopy, which showed a smooth surface, fiber bundles, gel-shaped nanofiber, and an average size of 94.05 nm with 69% of CNF in 34-100 nm size. The chemo-mechanical process exhibited a more crystalline nature in CNF than pulp kenaf. The low zeta potential values exhibit the distribution of fibrils and colloidal suspension stability without any further agglomeration. A lower concentration of CNF is less stable exhibiting the product agglomeration. Therefore, the chemo-mechanical process for the isolation of CNF (Hibiscus cannabinus) from kenaf involves sustainable, low-cost, non-toxic, and cheap alternatives than other traditional methods. [ABSTRACT FROM AUTHOR]

Digested sludge wasted by tanneries is rich in nutrients and trace elements however, the presence of toxic metals restricts their use in agriculture. The present study explores the possible application of tannery sludge amendment for the cultivation of an energy crop, Hibiscus cannabinus. The toxicity of various sludge amendments (25, 50, 75, and 100%, w/w) was examined during early seedling growth, followed by metal accumulation potential by performing pot experiments. Chemical characterization revealed the presence of Cr (709.6), Cu (366.43), Ni (74.6), Cd (132.71), Pb (454.8) µg.g-1 in tannery sludge beside N (2.1%), P 3.8 & K 316.96 (kg.hec-1.) respectively. Germination of H. cannabinus exposed to sludge extracts ranged between 80 to 95%; Relative seed germination, 81.33 to 84.43%. Relative root growth, 0.9 to 1.16 cm; and germination index, 95 to 110%. It was found that sludge extracts have not caused adverse effects on seed germination and early seedling growth. Heavy metal accumulation was observed as follows: Ni (3.37, 2.38, 1.46 & 0.90 mg.kg-1) > Pb (10.59, 10.15, 5.26, & 2.84 mg.kg-1) > Cu (2.34, 2.24, 0.97 & 0.24 mg.kg-1) > Cd (2.31, 1.19, 1.33 & 1.12 mg.kg-1) > Cr (1458, 1136.12, 601.73 & 211.6 mg.kg-1) in 100, 75, 50, & 25% sludge amended soil, respectively. The bio-concentration pattern of metals was found to be in the order of root > leaf > stem. The findings of the present study give direction for the eco-friendly and cost-effective management of tannery sludge. Further, H. cannabinus can be used for the restoration of metal-contaminated agricultural land, however, results need to be corroborated with field trials. [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]

This study was aimed to establish an efficient micropropagation protocol for three popular kenaf (Hibiscus cannabinus L.) cultivars (V36, HF992 and KB6) using different types of plant growth regulators (PGR’s) on Murashige and Skoog medium (MS). The shoot tip, cotyledon and hypocotyl isolated from 2 weeks old seedlings were used as explants. MS medium fortified with different types and concentrations of cytokinins and auxin were evaluated for establishment callus formation, shoot multiplication and rooting. Among different PGR’s used, 5.0 mg/l 2iP + 0.1 mg/l NAA was the best concentration for direct shoot regeneration from cotyledon with shooting percentage of 55% in HF992 cultivar. In multiple shoot induction experiment, 1.0 mg/l TDZ + 0.1 mg/l NAA mg/l concentration has induced the highest (10.4) shoots/explant. Moreover, indirect shoot regeneration was established from callus which was induced from cotyledon, maximum callus induction percentage (88.75%) was recorded on 0.5 mg/l TDZ and 1.0 mg/l NAA in V36 variety. While, for shoot elongation and rooting, MS media half strength supplemented with 1.0 mg/l kinetin + 1.0 mg/l IBA was found to be an optimum concentration. [ABSTRACT FROM AUTHOR]

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Apart from being utilized as a commercial fiber at maturity, kenaf shoots have potential as a food and feed source because of their diverse bioactivities. Previous studies have focused on mature stems because of their high biomass, whereas the antioxidant activities (AA) and the destination of AA contributors of kenaf stems and their high-yielding byproduct leaves during the growth stage have rarely been studied. Therefore, we investigated changes in AA and its relative components in kenaf leaves and stems during the four vital growth stages. Higher ABTS radical cation and DPPH radical scavenging abilities and ferric reducing antioxidant power, total phenolic content, total flavonoid content, and total polysaccharide content were observed at all leaf stages and in the late stem stages. Chlorogenic acid (CGA) and kaempferol glycosides, especially kaempferitrin (Kfr), were identified as representative phenolic acids and flavonoids in both kenaf leaves and stems. The content of CGA in both leaves and stems increased corresponding to the plant's growth stage, whereas kaempferol glycosides were enhanced in leaves but declined in stems. The highest correlation was observed between TPC and AA in all organs. Further evaluation of CGA and Kfr verified that CGA was the predominant contributor to AA, surpassing Kfr. These findings suggest that kenaf leaves increase antioxidant levels as they grow and can be a useful source of stem harvesting byproducts. [ABSTRACT FROM AUTHOR]

Over past decade, the increasing awareness about environment has prompted researchers to focus on crafting eco-friendly polymer composites using agricultural waste. Thus, the surge in environmental consciousness has driven researchers to prioritize the development of eco-friendly composite. Thus, this study endeavors to produce polyester hybrid laminates by combining kenaf(K)/glass(G) and pistachio shell particles (PSP) with varying percentages (0%, 1%, 3%, and 5%) by hand lay-up techniques. Various tests have been conducted to examine the mechanical and thermal properties of the produced hybrid laminates as per ASTM standard. The experimental results demonstrate a notable impact of filler concentration and stacking order on both mechanical and thermal characteristics. For KGKG laminate, significant improvements are seen in tensile strength (49.82%) and micro-hardness (54%) with 5 wt% PSP filler. Meanwhile, flexural strength increases by 60.69% and impact strength by 30.91% with 3 wt% PSP filler. Likewise, an improvement in tensile strength by 14.58%, flexural strength by 18.58%, impact strength by 3.53% and 2.3% increase in micro-hardness is also marked on alternation of stacking order. The GGGG-PSP5 laminate possesses higher storage modulus (9.21 GPa), loss modulus (2.57 GPa), damping factor (0.32) at 93.31º C than KKKK-PSP5 laminate. Furthermore, the micrographic analysis reveals significant occurrences of matrix cracking, fiber pull-out, micro-void formation, and fiber–matrix debonding in this integrated hybrid composite. Thus, the appropriate hybridization of synthetic and natural fibers can broaden the scope of the practical application of PSP with improved environmental friendliness in the automotive industry. [ABSTRACT FROM AUTHOR]

Copyright of Revista Hidalguía is the property of Revista Hidalguia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the effects of exogenous methyl jasmonate (MeJA) on metal uptake and its ability to attenuate metal toxicity in kenaf plants under Pb stress were investigated. The experiment was conducted with five different MeJA concentrations (0, 40, 80, 160, and 320 μM) as a foilar application to kenaf plants exposed to 200 μM Pb stress. The results revealed that pretreatmen of MeJA significantly increased plant dry weight, plant height, and root architecture at all concentrations tested, with the most significant increase at 320 μM. Foliar application of MeJA at 160 μM and 320 μM increased the Pb concentrations in leaves and stems as well as the translocation factor (TF) from root to leaf. However, the bioaccumulation factor in the shoot initially decreased and then increased with increasing MeJA concentration. By increasing enzymatic (SOD, POD, and CAT) and non-enzymatic (AsA and non-protein thiols) antioxidants, MeJA pretreatment decreased lipid peroxidation, O2− and H2O2 accumulation and recovered photosynthetic pigment content under Pb stress. Increased osmolytes (proline, sugar, and starch) and protein content after MeJA pretreatment under Pb stress restore cellular homeostasis and improved kenaf tolerance. Our results suggest that MeJA pretreatment modifies the antioxidant machinery of kenaf and inhibits stress-related processes that cause lipid peroxidation, hence enhancing plant tolerance to Pb stress. [ABSTRACT FROM AUTHOR]

Biochar derived from kenaf, a fast-growing plant, was used as a adsorbent in this study to remove phenol from aqueous solutions. Kenaf-derived biochar (KDB) was prepared at various temperatures (300–750 °C) and the relationship between the phenol adsorption mechanism and physicochemical properties was investigated. The highest phenol adsorption by KDB was achieved at 750 °C, and KDB pyrolyzed at 750 °C (KDB-750) had the lowest O/C (0.11) and H/C (0.01) values as well as the highest specific surface area (116.74 m2/g). Phenol molecules could be adsorbed on the surface of KDB via hydrophobic attraction and π–π interaction. Kinetic studies revealed that the adsorption reached equilibrium at 48 h, and the adsorption process was well explained by the pseudo-second-order model. The maximum phenol adsorbed obtained from equilibrium adsorption experiments was 41.1 mg/g, which is comparable to that reported in the literature. The enthalpy and entropy changes during phenol adsorption by KDB-750 were 22.3 kJ/mol and 64.2 J/K‧mol, respectively. The amount of phenol adsorbed decreased gradually from 38.5 to 32.4 mg/g as the pH of the solution increased from 3 to 9, and it decreased sharply from 32.4 to 28.9 mg/g as the pH increased from 9 to 11. When 0 to 200 mM NaCl was added to the phenol solution, the adsorbed amount decreased from 38.1 to 29.5 mg/g. Moreover, for a KDB-750 dosage of 10 g/L, > 90% of the phenol was removed. Thus, KDB-750, which is a low-cost and abundant adsorbent, could potentially be used as an adsorbent to remove phenol effectively. [ABSTRACT FROM AUTHOR]

The sowing date is a crucial factor for jute and allied fiber crops for better crop growth as well as fiber production. It is more important for advanced breeding lines before variety release. The purpose of this study was to provide information to breeders on the sowing time of advanced breeding lines of smooth Mesta, so they can recommend suitable sowing times for specific varieties. This study was carried out in the Jute Research Substation at Dinajpur, Bangladesh from March to July 2023. For the experimental treatments, three distinct sowing dates-namely, March 20th, March 30th, and April 10th were used, alongside the utilization of an advanced Mesta breeding line, SM-2, developed by the Bangladesh Jute Research Institute. A high-yielding Mesta variety, BJRI Mesta 3 (SAMU-93) was used as a control. A factorial RCBD design with three replications was used. Results showed that advanced breeding lines and sowing dates significantly affected plant height, base diameter, green weight with leaves, green weight without leaves, fiber yield and stick yield. Both the highest fiber yield (2.50 tha-1) and stick yield (5.00 tha1) were found when SM-2 was sown on 30th March. The second highest fiber yield (2.32 tha-1) and stick yield (4.64 tha-1) were found when SM-2 was sown on 10th April. The research showed that fiber yield and stick yields were 21 and 33% higher than the control respectively, when it was sown on 30 March. [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]

The essential objective of this work was to investigate the effect of silane treatment on the tensile and impact strength of composites made of jute/kenaf/glass fibers with the TiO2 nano-filler. This study also sought to optimize the factors connected with this treatment method. To develop and evaluate trials, the researchers used Response Surface Methodology (RSM) with central composite designs, emphasizing the optimization of silane concentration, immersion time, and nano-filler content. The researchers were able to effectively create quadratic models to forecast the tensile and impact strengths of the nano-composite throughout the silane treatment procedure. The adjustment of silane concentration, immersion duration, and nano-filler content discovered the best conditions for obtaining maximum tensile strength. The optimal values for silane concentration and immersion time have been identified to be 15 wt. % and 30 min, respectively. Considering these conditions, the composite's tensile strength increased by 32.13% and its impact strength improved by 8.34% above the lowest values achieved from RSM optimization. The results demonstrate the practical value of silane treatment, notably in boosting tensile and impact strengths while enhancing interfacial adhesive among natural fibers and polymer matrices. [ABSTRACT FROM AUTHOR]

The rigid polyurethane foams derived from liquefied kenaf (KPF) with different isocyanate (NCO) indexes were successfully produced by the one-shot method. Liquefied kenaf was obtained via the liquefaction process using PEG400/Gly as the solvent. The effect of NCO indexes on the foaming process and the physical, chemical, mechanical, and thermal properties of KPFs were investigated respectively. As the NCO indexes increased, the reaction rate of the foaming process, crosslinking density, compressive strength, and thermal stability of KPFs increased. The cellular morphology of KPF at 120 NCO index (KPF120) showed the largest average cell diameter (433.68 μm) with the highest water absorption ability, and the lowest apparent density (68.16 kg/m3). KPF120 also has the optimum compressive strength (170 kPa) and thermal stability. Rigid PU at formulation of KPF120 is comparable with the petroleum polyol based foams. [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]

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]

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Single-kenaf fiber-reinforced polymer composites are typically characterized by relatively low strength and stiffness properties that make them unsuitable for structural applications. However, they are lightweight, economical, and ecofriendly. This paper presents a study on the manufacturing and mechanical characterization of bidirectional kenaf (K) fiber-reinforced epoxy composites hybridized with carbon (C) fibers in various stacking sequences and the effects of hybridization on salient physical and mechanical properties. Single and hybrid fiber composites were fabricated utilizing the vacuum infusion molding technique. The density, tensile, flexural, and interlaminar shear properties in hybrid composites increased significantly when carbon fiber volume increased from 9% to 16%. Stacking sequences in a hybrid affected the mechanical properties of the composites. The highest tensile strength and modulus were shown by the seven-layer hybrid composite with an alternate K/C stacking sequence and C layers as skin layers, i.e., C/K/C/K/C/K/C, among all tested hybrid composites. Sandwich design in the hybrid (C2/K3/C2) had higher flexural strength (+300%), flexural modulus (+414%), interlaminar shear strength (+278%), lower water absorption (−46%), and thickness swelling (−30%) compared to single-fiber kenaf/epoxy composites. Density increased by 5% in hybrid composites. The highest fracture toughness (+134%) was achieved using the dual sandwich design structure hybrid (C/K2/C2/K2/C). The developed composite has applications in stairways, walkways, and bridges. [ABSTRACT FROM AUTHOR]

Hard tofu was developed from kenaf seed, and the effects of coagulant types and concentrations on the physicochemical, textural, and microstructural properties of the tofu were studied. Glucono delta-lactone (GDL), CH3COOH, MgCl2, and CaSO4 were the coagulants used at concentrations of 0.25, 0.5, 0.75, and 1.0 g% (w/v). Kenaf seed milky extract was obtained from the seed soaked at 65°C for 2 h 40 min, and ground using 1:6 seed-to-water ratio. The extracted milky extract was cooked to 95°C for 3 min, cooled to 80°C, and then coagulated with appropriate coagulant concentration. The yield, physicochemical, texture, and microstructure of the tofu were examined. The results indicated that the yield and moisture content of the tofu were not significantly affected by coagulant types and concentrations. Coagulant types affected the crude protein, crude fat, and surface colour of the tofu. GDL-coagulated tofu had significantly higher crude protein (35.09 - 39.07 g/100 g), while MgCl2-coagulated tofu had significantly higher crude fat (59.64 - 63.15 g/100 g). The hardness, chewiness, and springiness of the tofu were affected by the coagulant types and concentrations. CH3COOH-coagulated tofu had significantly higher hardness (2490.1 - 4005.8 g), while MgCl2-coagulated tofu had significantly lower hardness (814.45 - 2009.9 g). Scanning electron microscopy of all the tofu showed a rough-like structure of denser aggregated proteins with large pores, except for the tofu made with 0.25 g% (w/v) which exhibited a pseudo-honey-like structure of compacted network strands. It was concluded that all the coagulants at 0.25 g% (w/v) were suitable to produce kenaf seed tofu. [ABSTRACT FROM AUTHOR]

Improvement in thermal stability with the aim of homogeneous distribution of the active side of nanocellulose in this study was done with silanization treatment, which started with the treatment of silylated kenaf nanocellulose (SKNC) using 3-aminopropyltriethoxysilane in an alcohol solution at 25 °C with pH 4 within 4 h. Then, SKNC with a varied content of 0.5–2% (w/w) was added to polyvinyl alcohol (PVA). The SKNC was characterized by FT-IR, XRD, TEM, and TGA. The peak at 1571 cm−1 corresponding to N–H bending vibration was observed on SKNC spectra, indicating a successful silane treatment accompanied by a reduction of peak 1642 and 1425 cm−1, respectively. The crystallinity index for SKNC with antiparallel units were increased to 70.34% as compared with kenaf nanocellulose (KNC) (61.73%). TEM showed a form of needle-like structure for both SKNC and KNC. The interaction between SKNC and PVA was characterized by FT-IR with an increment of peak 1089 and 1028 cm−1, which shows the physical interaction that occurred between PVA and SKNC. The dispersion of SKNC was quite homogenous, as observed in FESEM. The SKNC exhibited a good thermal stability, and less amount of char was formed at 700 °C compared to kenaf extractive free. Furthermore, the TGA demonstrated better improvement after addition of 2% SKNC into PVA as well as for DSC results showed higher melting point of PVA composites. [ABSTRACT FROM AUTHOR]

Kenaf (Hibiscus cannabinus L.), in the Malvaceae family, is an important crop for not only fiber production, but also various other industrial materials. We performed phylogenetic analysis and a genome-wide association study (GWAS) of seven agronomic traits: days to flowering, plant height, fresh weight, dry weight, flower color, stem color, and leaf shape, using 96 kenaf genotypes, including gamma-irradiation-derived mutant lines. Genotypes were determined by genotyping-by-sequencing (GBS) and a total of 49,241 single-nucleotide polymorphisms (SNPs) were used in the analysis. Days to flowering, plant height, fresh weight, and dry weight were positively correlated with each other, and stem color was also correlated with fresh weight and dry weight. The phylogenetic analysis divided the 96 lines into nine related groups within two independent groups, and the GWAS analysis detected a total of 49 SNPs for days to flowering, plant height, fresh weight, dry weight, flower color, stem color, and leaf shape with −log10(P) ≥ 4, of which 22 were located in genic regions. The detected SNPs were located in genes with homology ranging from 45% to 96% to plants of the Malvaceae and Betulaceae, and these genes were found to be involved in plant growth and development via various pathways. Our identification of SNP markers related to agronomic traits is expected to help improve the quality of selective breeding programs for kenaf. [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 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]

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]

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]

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]

Kenaf (Hibiscus cannabinus L.) is considered suitable for the remediation of cadmium (Cd)-contaminated farmlands, because of its large biomass and resistance to Cd stress. The addition of nitrogen (N) fertilizer is an important measure used to increase crop yields, and it may also affect Cd accumulation in plants. To clarify the effects of different forms and concentrations of N on plant growth and Cd absorption in kenaf, a hydroponic experiment was conducted using three N forms (NH4+–N, NO3−–N and urea–N) at four concentrations (0, 2, 4 and 8 mM, 0 mM as control) under Cd stress (30 μM). The plant growth, the antioxidant enzyme activity and the Cd contents of various parts of the kenaf seedlings were measured. The results showed that the N form had the greatest impact on the growth of the kenaf and the absorption and transport of the Cd, followed by the interaction effect between the N type and the concentration. Compared to the control, the addition of N fertilizer promoted the growth of kenaf to varying degrees. Among all the treatments, the use of 2 mM of NO3−–N enhanced the biomass and Cd accumulation to the greatest extent compared to CK from 2.02 g to 4.35 g and 341.30 μg to 809.22 μg per plant, respectively. The NH4+–N significantly reduced the Cd contents of different parts but enhanced the translocation factors of Cd stem to root (TF S/R) and leaf to stem (TF L/S) by 34.29~78.57% and 45.10~72.55%, respectively. The peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) enzyme activities of the kenaf increased with the N treatments, especially with NH4+–N. Overall, applying low concentrations of NO3−–N can better promote the extraction of Cd by kenaf. [ABSTRACT FROM AUTHOR]

Production of kenaf polyols (KP) via liquefaction process was carried out using polyethylene glycol 400 and glycerol as the liquefying solvent. Optimization of parameters such as temperature, time, and the ratio of catalyst composition was done extensively. The effect of the hybridization of inorganic acid (sulphuric acid) and organic acid (lactic acid) as the liquefaction catalyst on the liquefaction product was studied. The results demonstrated that the lowest amount of residue (10.1%) was obtained at 160 °C with 3:1 (sulphuric acid: lactic acid) ratio of catalyst composition for 90 min. The hydroxyl (OH) number and viscosity of the kenaf polyol were examined. FTIR and NMR analyses revealed that most kenaf cellulose, hemicellulose, and lignin were degraded. XRD analysis was employed to examine the crystallinity index of kenaf residues (KR) at different temperatures, times, and catalyst ratio compositions. The morphology of KR at different temperatures was examined by using SEM analysis. The results showed that a smooth-surface KR was obtained at the optimum temperature (160 °C), indicating most of the cellulose was already decomposed at 160 °C. The optimized KP with OH number of 335.6 mg KOH/g and viscosity of 690 cP was used for the making of bio-based rigid polyurethane foam which is denoted as KPUF. The properties of KPUF and PUFs based petroleum polyol (PPUF) were compared. The density of KPUF (68.2 kg/m3) is lower compared to PPUF (131.9 kg/m3). The cellular structure and larger average cell diameter (0.617 mm) of KPUF enhance the water absorption ability which demonstrated that KPUF is capable to be utilized as growing media in the hydroponic system. [ABSTRACT FROM AUTHOR]