The current research aims to determine the requirements of Trends of International Mathematics and Science Study (TIMSS 2019) and to find out the extent to which the content of science textbooks for grades (1-4) in the Sultanate of Oman includes the requirements of (TIMSS 2019). Only the Cognitive Process dimension has been considered when conducting the analysis. The study population includes all science books from the first to the fourth grade for the academic year 2021-2022. The study identified and organized the requirements in the study tool, which is a list of requirements of (TIMSS 2019). After confirming its validity and reliability, the analysis was performed, and data were collected and analyzed statistically using frequencies and percentages. The results showed that all domains (knowledge, Applying, and Reasoning) and all cognitive skills for each domain were included in each grade, but the percentages included in the books differed always from those specified in the requirements of (TIMSS 2019). The rank of the included domains in grades 1, 3, and 4, were as follows: first, knowledge, second, Applying, and finally, Reasoning, which is the same rank proposed by (TIMSS 2019). However, the rank for grade 2 was different where Applying came first while Reasoning and knowledge came in the second and third ranks respectively. When frequencies and ratios were calculated for each of the three domains of cognitive processes cumulatively over the four years (1-4), an interesting result popped out. The percentage included for each of the three domains is close to the percentages specified by (TIMSS 2019). This means that the science textbooks (Cambridge) designed for students from the first grade to the fourth grade have balanced well between the percentages included and the percentages specified by (TIMSS 2019), but over the four years and not over one year only, as the difference between the percentages included and the percentages specified by (TIMSS 2019) in the field of knowledge was about 6.5 percentage points in favor of the percentage included, and the difference in the field of Applying was about 4.5 points Percentage in favor of the specified percentage. As for Reasoning, the difference was less than two points only in favor of the specified percentage, which means that there is a relatively greater focus on knowledge and relatively less on Applying and Reasoning.
In this work, metal oxide nanostructures, mainly copper oxide (CuO), nickel oxide (NiO), titanium dioxide (TiO2), and multilayer structure, were synthesized by the DC reactive magnetron sputtering technique. The effect of deposition time on the spectroscopic characteristics, as well as on the nanoparticle size, was determined. A long deposition time allows more metal atoms sputtered from the target to bond to oxygen atoms and form CuO, NiO, or TiO2 molecules deposited as thin films on glass substrates. The structural characteristics of the final samples showed high structural purity as no other compounds than CuO, NiO, and TiO2 were found in the final samples. Also, the prepared multilayer structures did not show new compounds other than th
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Background: Bacteriocin is a peptidic toxin has many advantages to bacteria in their ecological niche and has strong antibacterial activity. Objective: The aim of this study was to evaluation of bacteriocin using Streptococcus sanguinis isolated from human dental caries.
Subjects and Methods: Thirty five streptococcus isolates were diagnosed and tested for their production of bacteriocin, and then the optimal conditions for production of bacteriocin were determined. After that, the purification of bacteriocin was made partially by ammonium sulfate at 95% saturation levels, followed by and gel filtration chromatography
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In this work, enhancement to the fluorescence characteristics of laser dye solutions hosting highly-pure titanium dioxide nanoparticles as random gain media. This was achieved by coating two opposite sides of the cells containing these media with nanostructured thin films of highly-pure titanium dioxide. Two laser dyes; Rhodamine B and Coumarin 102, were used to prepare solutions in hexanol and methanol, respectively, as hosts for the nanoparticles. The nanoparticles and thin films were prepared by dc reactive magnetron sputtering technique. The enhancement was observed by the narrowing of fluorescence linewidth as well as by increasing the fluorescence intensity. These parameters were compared to those of the dye only and the dye solution
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Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared w
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