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The use of synthetic pesticides has come under scrutiny, and there has been a subsequent shift toward the investigation of alternative methods for the treatment of plant diseases. One notable advancement in this field is the utilization of porous silicon (PS) powder as a sustainable antifungal agent. The synthesis of PS nanoparticle (PS-NP) powder was carried out using the environmentally friendly ultrasonication process. X-ray powder diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, UV-VIS absorbance, and photoluminescence were some of the methods used to characterize PS-NPs. The different characterization methods revealed the formation of a nanocrystalline structure possessing a cubic Si crystalline quality. The crystal size of PS-NPs, as determined from X-ray diffractometer data, ranges from 36.67 to 52.33 nm. The obtained PS has a high band gap of 3.85 eV and presents a photoluminescence peak at 703 nm. The antifungal activity of the synthesized PS-NPs was assessed against three molecularly characterized fungi, namely Rhizoctonia solani, Fusarium oxysporum, and Botrytis cinerea, which were obtained from tomato plants. The concentration of PS-NPs at 75 µg/mL exhibited the highest enhancement in growth inhibition percentages as compared to the control group. R. solani had the highest inhibition percentage of 82.96%. In conclusion, the encouraging structural properties and antimicrobial capabilities of PS-NPs pave the way for their application across diverse technological industries. To the best of our knowledge, this is the first in vitro study of PS-NPs to evaluate their fungal control efficiency.

This paper presents an analysis of long, large-diameter bored piles' behavior under static and dynamic load tests for a megaproject located in El Alamein, on the northern shoreline of Egypt. Site investigations depict an abundance of limestone fragments and weak argillaceous limestone interlaid with gravelly, silty sands and silty, gravelly clay layers. These layers are classified as intermediate geomaterials, IGMs, and soil layers. The project consists of high-rise buildings founded on long bored piles of 1200 mm and 800 mm in diameter. Forty-four (44) static and dynamic compression load tests were performed in this study. During the pile testing, it was recognized that the pile load–settlement behavior is very conservative. Settlement did not exceed 1.6% of the pile diameter at twice the design load. This indicates that the available design manual does not provide reasonable parameters for IGM layers. The study was performed to investigate the efficiency of different approaches for determining the design load of bored piles in IGMs. These approaches are statistical, predictions from static pile load tests, numerical, and dynamic wave analysis via a case pile wave analysis program, CAPWAP, a method that calculates friction stresses along the pile shaft. The predicted ultimate capacities range from 5.5 to 10.0 times the pile design capacity. Settlement analysis indicates that the large-diameter pile behaves as a friction pile. The dynamic pile load test results were calibrated relative to the static pile load test. The dynamic load test could be used to validate the pile capacity. Settlement from the dynamic load test has been shown to be about 25% higher than that from the static load test. This can be attributed to the possible development of high pore water pressure in cohesive IGMs. The case study analysis and the parametric study indicate that AASHTO LRFD is conservative in estimating skin friction, tip, and load test resistance factors in IGMs. A new load–settlement response equation for 600 mm to 2000 mm diameter piles and new recommendations for resistance factors φ qp, φ qs, and φ load were proposed to be 0.65, 0.70, and 0.80, respectively. [ABSTRACT FROM AUTHOR]

Abstract The basic function of retaining walls is to support soil backfill and water. This function has to be adequate under different conditions of loading; with permissible deformations. Researches are addressing the reduction of the exerted lateral earth thrust and water pressures to satisfy the adequacy in reasonable costs. Expanded polystyrene geofoam, EPSG, is the most popular material adopted to decrease lateral earth thrust on retaining walls. This paper presents an article review on researches of this aspect. Equations were proposed for reduction in lateral forces and overturning moments. Its aim is to optimize the design of 8.0 m gravity retaining wall with installation of EPSG.

Sodium ion batteries are favored in stationary and large scale power storage due to their low cost and nontoxicity. As the lithium is replaced with sodium due to the cost motive, a cheap processing method is needed to maintain the cell price as low as possible. We report an ultra-fast synthesis method that utilizes the high microwave absorbance of silicon carbide content in rice straw ash. Amorphous/maricite mixtures of sodium iron phosphates-carbon composites (NaFePO4-C) are synthesized, crystallized, and carbon coated using one-step microwave heating. The sodium ion electroactive composites are prepared using different microwave heating durations ranging from 30 to 100 s. High purity inert gases are not needed during synthesis, processing, and even at cell assembly. The materials are characterized by elemental analysis techniques, X-ray diffraction (XRD), scanning/transmission electron microscope (SEM/TEM), and Raman spectroscopy. The electrochemical performance of the synthesized nanocomposites is examined as sodium ion battery cathode and as symmetric supercapacitors. The optimum synthesis time is 60 s for the application as sodium ion batteries and as a supercapacitor. The maximum specific capacity is 108.4 mA h g−1 at 0.2 C in the case of using it as a battery cathode. While the capacitance is 86 F g−1 at 0.5 A g−1 as a supercapacitor. The capacity retention is 92.85% after 40 cycles at 0.2 C as sodium ion battery electrode. For supercapacitor, the capacity retention is 81.7% after 1000 cycles. [ABSTRACT FROM AUTHOR]

Microbial contamination is one of the major dreadful problems that raises hospitalization, morbidity and mortality rates globally, which subsequently obstructs socio-economic progress. The continuous misuse and overutilization of antibiotics participate mainly in the emergence of microbial resistance. To circumvent such a multidrug-resistance phenomenon, well-defined nanocomposite structures have recently been employed. In the current study, a facile, novel and cost-effective approach was applied to synthesize Ag@Ag2O core–shell nanocomposites (NCs) via chemical method. Several techniques were used to determine the structural, morphological, and optical characteristics of the as-prepared NCs. XRD, Raman, FTIR, XPS and SAED analysis revealed a crystalline hybrid structure of Ag core and Ag2O shell. Besides, SEM and HRTEM micrographs depicted spherical nanoparticles with size range of 19–60 nm. Additionally, zeta potential and fluorescence spectra illustrated aggregated nature of Ag@Ag2O NCs by − 5.34 mV with fluorescence emission peak at 498 nm. Ag@Ag2O NCs exhibited higher antimicrobial, antibiofilm, and algicidal activity in dose-dependent behavior. Interestingly, a remarkable mycocidal potency by 50 μg of Ag@Ag2O NCs against Candida albican; implying promising activity against COVID-19 white fungal post-infections. Through assessing cytotoxicity, Ag@Ag2O NCs exhibited higher safety against Vero cells than bulk silver nitrate by more than 100-fold. [ABSTRACT FROM AUTHOR]

The increased terrorist and vandalism attacks on important public structures and utilities have raised the vital necessity for the investigation of performance of structures under blast loads to improve the design and enhance the behavior of structures subjected to such threats. In this study, 3-D finite element analysis is used to study the effect of surface explosions on the response of RC bored tunnels. The soil behavior is modelled using Drucker-Prager Cap model. Two types of soil are investigated, and the blast load is considered through various weights of TNT explosive charges at heights of 0.50 m and 1.0 m from ground surface. To study the effect of horizontal standoff distance, six different horizontal distances are considered. The results show that the soil type has a significant effect on tunnel response due to surface blasts. Also the weight and the location of charge have a great effect on the safety of the tunnel. Finally, a parametric study is established to define the borders of the restricted area around the tunnel location to be safe. [ABSTRACT FROM AUTHOR]