Broadband absorbers are required for solar energy harvesting because they efficiently absorb the incident photon in the wide-ranging solar spectrum. To ensure high absorption of photons, metamaterial absorbers (MMAs) have been a growing area of interest in recent years. In this article, an MMA is proposed using a metal–insulator–metal (MIM) structure (Ni–SiO2–Ni) that shows a near-unity broadband absorption of wavelengths from 300 to 1600 nm, with a 95.77% average absorption and a peak absorption of 99.999% at 772.82 nm. The MMA is polarization insensitive as well as wide incident angle stable. Analysis of the effects of mechanical bending on the absorption of the proposed structure shows that absorption holds satisfactory values at different degrees of mechanical loading. The suggested MMA unit cell structure was computationally simulated using the Finite Integration Technique (FIT) and verified using the Finite Element Method (FEM). To analyze the feasibility of the proposed MMA as a solar cell, it is investigated with the universal AM 1.5 solar spectrum characteristics. Besides solar energy harvesting, the proposed MMA unit cell may be employed in a variety of diverse optical applications, including sensors, detectors, and imaging.

The study aimed to determine the prevalence of ADHD symptoms in Saudi children aged 6 to 13 years in Jeddah city. The study also explored the effect of variables namely teacher's knowledge, years of experience and teachers' gender on reported ADHD symptoms among primary grade students. A questionnaire survey methodology was adopted for the study. 550 children were included in the teachers' survey. Teachers assessed the ADHD symptoms in children using an 18-item scale based on DSM-V. The results indicated that the prevalence rates of ADHD among school-age differed according to ADHD subtypes. The Inattention type was rated by 35.34%, Hyperactivity/Impulsivity type was rated by 28.60%, and ADHD-C type was rated by 21.3% of the respondents. According to gender, for the Inattention subtype, the ratio between boys and girls was 1.7:1, for the Hyperactivity/Impulsivity subtype, the ratio between boys and girls was 2.03:1, and for combined subtype, the ratio between boys and girls was 2.2:1. According to the grade level, the highest prevalence of ADHD overall was found in grade three and the lowest prevalence was in grade six in all ADHD types. The present findings indicated that teachers' knowledge and gender (female) successfully predicted teacher-rated ADHD status.

No abstract

No abstract

No abstract