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1.
Molecules ; 28(6)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36985764

RESUMO

With the ever-increasing world population, the energy produced from green, environmentally friendly approaches is in high demand. In this work, we proposed a green and cost-effective strategy for synthesizing a porous carbon electrode decorated with alumina oxide (Al2O3) from cherry blossom leaves using the pyrolysis method followed by a sol-gel method. An Al2O3-coating nano-layer (4-6 nm) is formed on the porous carbon during the composition fabrication, which further adversely affects battery performance. The development of a simple rich-shell-structured C@Al2O3 nanocomposite anode is expected to achieve stable electrochemical performances as lithium storage. A significant contributing factor to enhanced performance is the structure of the rich-shell material, which greatly enhances conductivity and stabilizes the solid-electrolyte interface (SEI) film. In the battery test assembled with composite C@Al2O3 electrode, the specific capacity is 516.1 mAh g-1 at a current density of 0.1 A g-1 after 200 cycles. The average discharge capacity of carbon is 290 mAh g-1 at a current density of 1.0 A g-1. The present study proposes bioinspired porous carbon electrode materials for improving the performance of next-generation lithium-ion batteries.

2.
Materials (Basel) ; 14(5)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800474

RESUMO

To date, breakdown voltage is an underlying risk to the epoxy-based electrical high voltage (HV) equipment. To improve the breakdown strength of epoxy resin and to explore the formation of charge traps, in this study, two types of polyhedral oligomeric silsesquioxane (POSS) fillers are doped into epoxy resin. The breakdown voltage test is performed to investigate the breakdown strength of neat epoxy and epoxy/POSS composites. Electron traps that play an important role in breakdown strength are characterized by thermally stimulated depolarized current (TSDC) measurement. A quantum chemical calculation tool identifies the source of traps. It is found that adding octa-glycidyl POSS (OG-POSS) to epoxy enhances the breakdown strength than that of neat epoxy and epoxycyclohexyl POSS (ECH-POSS) incorporated epoxy. Moreover, side groups of OG-POSS possess higher electron affinity (EA) and large electronegativity that introduces deep-level traps into epoxy resin and restrain the electron transport. In this work, the origin of traps has been investigated by the simulation method. It is revealed that the functional properties of POSS side group can tailor an extensive network of deep traps in the interfacial region with epoxy and enhance the breakdown strength of the epoxy/POSS nanocomposite.

3.
Saudi J Biol Sci ; 27(12): 3199-3207, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33304125

RESUMO

This study focuses on the synthesis, characterization, and assessment of the synergistic effect of 2,2,6,6, tetramethylpiperidine-N-oxyl (TEMPO)-coated titanium dioxide nanorods (TiO2 NRs) for photodynamic therapy (PDT). Firstly, TiO2 NRs were synthesized by the sol-gel technique. Then, TEMPO was grafted on TiO2 NRs with the aid of oxoammonium salts. Next, the final product was characterized by applying manifold characterization techniques. X-ray diffraction was used to perform crystallographic analysis; transmission electron microscopy (TEM) was used to conduct morphological analysis; Fourier transform infrared (FTIR) and Raman spectra were recorded to perform molecular fingerprint analysis. Furthermore, experimental and empirical modeling was performed to confirm the suitability of as-prepared samples for PDT applications using (MCF-7 cell line) Human Breast Cancer cell line. Our results revealed that bare TiO2 NRs did not exhibit a significant response for therapeutic applications compared to TEMPO-conjugated TiO2 NRs in the dark; however, they exhibited a prominent response for the PDT application under UV-A light. Therefore, it is concluded that TEMPO-coated TiO2 NRs shows the synergistic response for therapeutic approach under UV-A light irradiation. In addition, TEMPO capped TiO2 nanorods not only overcome the multidrug resistance (MDR) hindrance but also exhibit excellent response for cancer cell (MCF-7 cells) treatment only under UV light irradiation via PDT. It is expected that the proposed TiO2 NRs + TEMPO nanocomposite, which is suitable for PDT treatment, may be essential for photodynamic therapy.

4.
Saudi J Biol Sci ; 27(1): 401-406, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31889863

RESUMO

Red palm weevil (RPW) causes severe damage to date palm trees, leading to the death of trees if not detected and treated in time. A major obstacle in RPW control is the difficulty in identifying an early stage infestation In the present study, we measured the efficacy of some non-invasive optical devices including cameras (digital camera and thermal camera), TreeRadarUnit™ (TRU) (Radar 2000, Radar 900), resistograph, magnetic DNA biosensor, and Near-infrared Spectroscopy (NIRS) to detect RPW infestation in date palm trees under field conditions at Riyadh, Saudi Arabia. Date palm trees used in these experiments were selected based on visual observations. After inspection of date palm trees with different devices to detect RPW infestation, each tree was taken down and dissected in detail to validate the accuracy of each device. Results indicated that the visual RPW detection approach presented the highest accuracy (87%) followed by Radar 2000 (77%), Radar 900 (73%), resistograph (73%), thermal camera (61%), and digital camera (52%). Moreover, different stages of RPW placed in plastic cups were fastened onto the healthy date palm trunks to judge RPW presence, the magnetic DNA biosensor correctly detected RPW eggs 75% of the time, followed by detection of larvae (64%) and the control (empty cup) (54%). In another experiment where determinations were made in an open area, the efficiency of the DNA biosensor for detecting adults was 100%, followed by 83%, 63%, 60%, and 39% for pupae, larvae, eggs, and control, respectively. Absorption spectra generated through NIRS for infested, wounded, and control samples of date palm tissue showed a remarkable variation in the gradient of the corresponding peaks between 1850 nm and 1950 nm. Based on the detection efficiency of the tested devices, the resistograph and NIRS have the best potential to detect RPW infestation in date palm trees.

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