Herein, we report a facile preparation of super-hydrophilic sand by coating the sand particles with cross-linked polyacrylamide (PAM) hydrogels for enhanced water absorption and controlled water release aimed at desert agriculture. To prepare the sample, 4 wt% of aqueous PAM solution is mixed with organic cross-linkers of hydroquinone (HQ) and hexamethylenetetramine (HMT) in a 1:1 weight ratio and aqueous potassium chloride (KCl) solution. A specific amount of the above solution is added to the sand, well mixed, and subsequently cured at 150 °C for 8 h. The prepared super-hydrophilic sands were characterized by Fourier-transform infrared spectroscopy (FT-IR) for chemical composition and X-ray diffraction (XRD) for successful polymer coating onto the sand. The water storage for the samples was studied by absorption kinetics at various temperature conditions, and extended water release was studied by water desorption kinetics. The water swelling ratio for the super-hydrophilic sand has reached a maximum of 900% (9 times its weight) at 80 °C within 1 h. The desorption kinetics of the samples showed that the water can be stored for up to a maximum of 3 days. Therefore, super-hydrophilic sand particles were successfully prepared by coating them with PAM hydrogels, which have great potential to be used in sustainable desert agriculture.
This paper is devoted to the determination of the dispersive component of the surface energy of two boron materials such as h-BN and BPO4 surfaces by using the inverse gas chromatography (IGC) at infinite dilution. The specific interactions and Lewis’s acid-base parameters of these materials were calculated on the light of the new thermal model concerning the dependency of the surface area of organic molecules on the temperature, and by using also the classical methods of the inverse gas chromatography as well as the different molecular models such as Van der Waals, Redlich-Kwong, Kiselev, geometric, Gray, spherical, cylindrical and Hamieh models. It was proved that h-BN surface exhibits higher dispersive surface energy than BPO4 material.
The specific properties of interaction of the two boron materials were determined. The results obtained by using the new thermal model taking into account the effect of the temperature on the surface area of molecules, proved that the classical IGC methods, gave inaccurate values of the specific parameters and Lewis’s acid base constants of the solid surfaces. The use of the thermal model allowed to conclude that h-BN surface has a Lewis basicity twice stronger than its acidity, whereas, BPO4 surface presents an amphoteric character.
Magnetic graphene oxide nanocomposites (M-GO) were successfully synthesized by partial reduction co-precipitation method and used for removal of Sr(II) and Cs(I) ions from aqueous solutions. The structures and properties of the M-GO was investigated by X-ray diffraction, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometer (VSM) and N2-BET measurements. It is found that M-GO has 2.103 mg/g and 142.070 mg/g adsorption capacities for Sr(II) and Cs(I) ions, respectively. The adsorption isotherm matches well with the Freundlich for Sr(II) and Dubinin–Radushkevich model for Cs(I) and kinetic analysis suggests that the adsorption process is pseudo-second-ordered.
The study’s objective is to identify the challenges and limitations faced by the current vocational education system in preparing graduates in the era of the industrial revolution in the evolving job market in Tangerang, Indonesia. The study primarily examines vocational high schools and adopts a quantitative and quasi-experimental research approach, using control groups to conduct pre- and posttests. The experimental group experiences demonstrations, whereas the control group receives explanations. Instructors employ a blend of demonstration and explanation techniques to explain equipment operation before allowing students to engage in vocational training. The study, led by students in various engineering fields, evaluates technical competencies, work ethics, and foundational knowledge using tests and observations. Job preparation is assessed using the minimal completeness criteria (MCC), which focuses on the importance of proper knowledge, attitudes, and skills. The results indicate that vocational teachers have the potential to play a pivotal role in introducing cutting-edge, technology-based teaching methods, therefore enabling students to make well-informed decisions about their careers. This research enhances vocational education by incorporating practical skills and attitudes with academic knowledge, effectively addressing the changing requirements of the work market.
As the population’s demand for food continues to increase, aquaculture is positioned as a productive activity that provides high-quality protein. Aquaculture activity is characterized by its socio-economic impact, the generation of jobs, its contribution to food, and constant growth worldwide. However, in the face of threats of competition, producers must quickly adapt to market needs and innovate. Given this, this research aims to analyze the impact of the knowledge absorption capacity with the adoption of innovations by aquaculture producers in the Mezquital Valley in Hidalgo, Mexico. The methodological strategy was carried out through structural equation modeling using partial least squares and correlation tests. The findings show that knowledge absorption capacities explain 77.8% of the innovations carried out in aquaculture farms. Both variables maintain a medium-high correlation; the more significant the absorption capacity, the greater the innovation.
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