In this work, the surface of nano/micro-E-glass fibril (nGF) was modified with an amine silane coupling agent before applying as toughener for epoxy resin. The chemical structure and composition of ...silanized glass fibril (s-nGF) were also confirmed and compared with virgin nano/micro-glass fibrils. The curing reaction of epoxy samples with various s-nGF contents was performed at room temperature. Many characteristics of composite samples were also examined such as mechanical properties, fracture energy, thermal stability, and morphology. The experimental testing indicated that the s-nGF helps to improve the mechanical, thermal stability as well as the fracture energy of epoxy resin. The morphology observation also indicated that the s-nGF prevented the crack growth inside the epoxy matrix as the main reason of the enhancing fracture energy of epoxy resin with the presence of s-nGF.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Micropropagation has proven to be an effective method for large-scale plant production in a short time and a useful tool for plant breeding. Microbial contamination is one of the most difficult ...micropropagation challenges, resulting in reduced plant quality and loss of valuable stocks. Therefore, sterilization of culture media is a critical step in plant micropropagation. However, sterilized media might reduce the activity of plant growth regulators and nutritional components of culture media. The sterilization effects of silver nanoparticles (AgNP) on the growth of explants and culture media were examined. The treatment with 250 ppm AgNP for 15 to 20 min of 4-wk-old
ex vitro
leaves proved optimal for controlling the contamination. Furthermore, the Murashige and Skoog medium containing 4 ppm AgNP resulted in 100% medium disinfection (no contamination) after 4 wk of culture. The plantlets obtained from non-sterilized MS medium (NoM) containing 4 ppm AgNP and 4 g L
−1
agar gave similar results as the control medium with 8 g L
−1
agar and the absence of AgNP. Large scale culture systems using NoM in large plastic containers of two different sizes (NoM1 and NoM2) could produce quality plantlets. Chrysanthemum plantlets in the NoM1 system showed higher antioxidant enzyme activities of ascorbate peroxidase and superoxide dismutase than plantlets in the autoclaved medium. Furthermore, the plantlets from NoM were better acclimatized under greenhouse conditions than those from the autoclaved medium (AuM) system. The developmental stages (flower buds and blooming time) of NoM1 and NoM2 plantlets, were 1 wk earlier than those from the AuM system. The successful use of AgNP as a sterilizer and as a component of culture media would reduce the cost of micropropagation and improve plants' quality.
This paper presents an effective method for enhancing both the mode I (
G
IC
) and mode II (
G
IIC
) interlaminar fracture toughness of carbon fiber reinforced epoxy resin (CFRE). For precursor ...materials, silk fibroin nanofibers (nSF) and rice husk silica were prepared from sustainable resources. Nanocomposite samples were prepared using various loading ratios of the silica and nSF in epoxy resin (EP). Mechanical stirring and sonication techniques were used to prepare homogenous mixtures of silica and nSF in epoxy resin. Non-isothermal differential scanning calorimetry and the Kissinger equation were used to examine and calculate the cure kinetics and activation energy (
E
a
) of EP and the composite samples. The CFRE sample with hybrid fillers of nSF and silica at the ratio 0.2/20 (wt%/wt%) exhibited the highest
G
IC
, and improved upon the mode-I and mode-II toughness of the pure-resin sample by 36.08% and 30.06%, respectively. Study of the fracture surfaces indicated that adding nSF and silica as fillers increases the energy required to fracture the CFRE.
Exploring structural biomimicry is a great opportunity to replicate hierarchical frameworks inspired by nature in advanced functional materials for boosting new applications. In this work, we present ...the biomimetic integration of polythiophene into chitosan nanofibrils in a twisted Bouligand structure to afford free-standing macroscopic composite membranes with electrochemical functionality. By considering the integrity of the Bouligand structure in crab shells, we can produce large, free-standing chitosan nanofibril membranes with iridescent colors and flexible toughness. These unique structured features lead the chitosan membranes to host functional additives to mimic hierarchically layered composites. We used the iridescent chitosan nanofibrils as a photonic platform to investigate the host–guest combination between thiophene and chitosan through oxidative polymerization to fabricate homogeneous polythiophene-wrapped chitosan composites. This biomimetic incorporation fully retains the twisted Bouligand organization of nanofibrils in the polymerized assemblies, thus giving rise to free-standing macroscopic electrochemical membranes. Our further experiments are the modification of the biomimetic polythiophene-wrapped chitosan composites on a glassy carbon electrode to design a three-electrode system for simultaneous electrochemical detection of uric acid, xanthine, hypoxanthine, and caffeine at trace concentrations.
In this study, suspensions of core–shell particles dispersed in a silicone oil were fabricated and their rheological properties were evaluated at different external electric field strengths. The ...core–shell-structured composite materials were synthesized by coating poly(
o
-toluidine) (PoT) shells on the surfaces of silica particles. The silica particles were extracted from rice husk through acid and thermal treatments. The silica particles were then modified with (3-trimethoxysilyl)propyl methacrylate prior to the coating with the PoT shells. The chemical structures, morphologies, particle sizes, and elemental distributions of both silica and core–shell particles were investigated using scanning electron microscopy, Fourier-transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy. Additionally, the rheological properties, chain formations, and dielectric properties of the suspensions were analyzed using rotational rheometry, optical microscopy, and an inductance–capacitance–resistance meter. The shear stress increased with the electric field strength along with the electro-rheological efficiency. The plot of the yield stress against the applied electric field strength exhibited a slope of 1.5. The fabricated core–shell particles are environment-friendly and are promising materials for applications in next-generation electro-rheological fluids.
•CaSWEET genes play important roles in plant responses to stressful conditions.•Twenty-one CaSWEET genes were identified and characterized in chickpea.•CaSWEET genes showed differential expression ...under abiotic stress conditions.•Twelve CaSWEET genes were up-regulated in dehydrated leaves and/or roots.•CaSWEET20 was the most induced gene in both dehydrated leaves and roots.
‘Sugars Will Eventually be Exported Transporters’ (SWEETs) are a group of sugar transporters that play crucial roles in various biological processes, particularly plant stress responses. However, no information is available yet for the CaSWEET family in chickpea. Here, we identified all putative CaSWEET members in chickpea, and obtained their major characteristics, including physicochemical patterns, chromosomal distribution, subcellular localization, gene organization, conserved motifs and three-dimensional protein structures. Subsequently, we explored available transcriptome data to compare spatiotemporal transcript abundance of CaSWEET genes in various major organs. Finally, we studied the changes in their transcript levels in leaves and/or roots following dehydration and exogenous abscisic acid treatments using RT-qPCR to obtain valuable information underlying their potential roles in chickpea responses to water-stress conditions. Our results provide the first insights into the characteristics of the CaSWEET family members and a foundation for further functional characterizations of selected candidate genes for genetic engineering of chickpea.
Micron-size white bamboo fibrils were fabricated from white bamboo and used as a source for the production of highly porous and very lightweight cellulose aerogels for use as a potential oil ...absorbent. The aerogels were fabricated through gelation from an aqueous alkali hydroxide/urea solution, followed by a conventional freeze-drying process. The morphology and physical properties of the aerogels were characterized by field emission scanning electron microscopy and Brunauer-Emmett-Teller surface area analysis, respectively. Successful silanization of the cellulose aerogel was confirmed by energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and water contact angle measurements. The fabricated silane cellulose aerogel exhibited excellent absorption performance for various oil and organic solvents with typical weight gains ranging from 400% to 1200% of their own dry weight, making them promising versatile absorbents for a range of applications, including water purification.
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•Platinum/reduced graphene oxide (Pt/rGO) composite pastes were successfully synthesized.•The annealing temperature of 450 °C was appropriate for fabrication of Pt/rGO ...cathodes.•Pt/rGO cathodes were fabricated with high electrochemical properties.•DSSCs fabricated from Pt/rGO cathodes demonstrated high conversion efficiencies.
Platinum/reduced graphene oxide (Pt/rGO) composite materials with different mass ratios were fabricated by thermal decomposition method from H2PtCl6 and reduced graphene oxide (rGO) as precursors. The Pt/rGO composites were used for fabrication of Pt/rGO cathodes by the screen-printing method. The electrochemical properties of the fabricated cathodes were measured using cyclic voltammetry. The dye-sensitized solar cells (DSSCs) were assembled from fabricated cathodes and tested by current density–voltage
(J-V) curves and electrochemical impedance spectroscopy (EIS). The results showed that the appropriate replacement amount of rGO for Pt was 20 wt%, with the efficiency of 6.42%, higher than that of commercial Pt cathode. The characterization of the appropriate Pt/rGO composite was investigated by Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and transmission electron microscopy. The characterization results demonstrated that Pt/rGO composite material was synthesized and the Pt nanoparticles with size of 10–30 nm were evenly distributed on the rGO sheets. These results indicated that Pt/rGO could be appropriated material to replace Pt in DSSCs in order to reduce the production cost and maintain efficiency.
Many education facilities have recently switched to online learning due to the COVID-19 pandemic. The nature of online learning makes it easier for dishonest behaviors, such as cheating or lying ...during lessons. We propose a new artificial intelligence - powered solution to help educators solve this rising problem for a fairer learning environment. We created a visual representation contrastive learning method with the MobileNetV2 network as the backbone to improve predictability from an unlabeled dataset which can be deployed on low power consumption devices. The experiment shows an accuracy of up to 59%, better than several previous research, proving the usability of this approach.
Constructed wetlands (CWs) are a widely utilized nature-based wastewater treatment method for various effluents. However, their application has been more focused on pilot and full-scale CWs with ...substantial surface areas and extended operation times, which hold greater relevance in practical scenarios. This study used kinetics, linear regression (LR), and machine learning (ML) models to estimate effluent ammonium in pilot and full-scale CWs. From screening 1476 papers, 24 pilot and full-scale CW studies were selected to extract data containing 15 features and 975 data points. Nine models were fit to this data, revealing that linear models were less effective in capturing CW effluent compared to nonlinear ML algorithms. For training data, the Monod kinetic model predicted the poorest performance with an RMSE of 41.84 mg/L and R2 of 0.34, followed by simple LR (RMSE 24.29 mg/L and R2 0.77) and multiple LR (RMSE 22.63 mg/L and R2 0.80). In contrast, Cubist and Random Forest achieved high performances, with an average RMSE of 12.01 ± 5.38 and an average R2 of 0.93 ± 0.07 for Cubist, and an average RMSE of 15.94 ± 10.69 and an average R2 of 0.91 ± 0.08 for RF. The trained Random Forest performed the best for new data, with an R2 of 0.93 and RMSE of 13.48 mg/L. This ML-based model is a valuable tool for efficiently estimating effluent ammonium concentration in pilot and full-scale CWs, thereby facilitating the design of systems.
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•Real-world data from pilot/full-scale CWs were aggregated and analyzed•Estimated ammonium changes in full-scale CWs using various models were evaluated•Non-linear machine learning predicted NH4-N more than kinetic and linear regression•Best predictive model for new data was random forest with R2 = 0.93, error = 0.38 %•Data-driven modelling demonstrated its applicability for efficiently assessing ammonium in CWs.
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