The present work divided into two parts, first the experimental side which included the
measuring of the first natural frequency for the notched and unnotched cantilever composite beams
which consisted of four symmetrical layers and made of Kevlar- epoxy reinforced. A numerical
study covers the effect of notches on the natural frequencies of the same specimen used in the
experimental part. The mathematical model for the beam contains two open edges on the upper
surface. The effect of the location of cracks relative to the restricted end, depth of cracks, volume
fraction of fibers and orientation of the fiber on the natural frequencies are explored. The results
were calculated using the known engineering program (ANSY

This study aimed to determine the measurements and classification of Schneider membrane thickness correlated to age and sex factors using cone beam computed tomography (CBCT). Methods: The study included CBCT images for 100 maxillary sinuses of 50 consecutive patients, and the thickness of the maxillary sinus membrane (Schneiderian membrane) was measured in coronal view from the lowest point in the floor of the maxillary sinus to the highest point. The thickness of the Schneiderian membrane was classified into 4 types. Results: The study result revealed that out of the total cases, 45% of sinus membranes were classified as type 2, while only 10% were classified as type 4. The most frequent type of membrane thickness diagnosed in the age gro

   This study demonstrates a sustainable, "trash-to-treasure" approach by synthesizing silica (SiO2) and alumina (Al2O3) nanoparticles (30–80 nm) from local waste materials—specifically bentonite clay and aluminum wire waste—and evaluating their performance as eco-friendly additives in 350 mL water-based drilling fluids at concentrations ranging from 0 to 1 g. Tested under harsh subsurface conditions, the incorporated nanoparticles significantly enhanced the fluids' rheological properties, lubricity, filtration control, and swelling inhibition, with performance scaling alongside nanoparticle concentration. Notably, at a 1 g dosage, the fluid's yield point spiked from a baseline of 9 to 42 for SiO2 and 32 for (Al2O3), while h

The addition of nanoparticles to the drilling fluids for geological projects is a promising application for enhancing the stability, rheological properties, and overall performance of the mud. This study aims to thoroughly analyze and compare the effects of silica and alumina nanoparticles on the properties and effectiveness of polymer drilling mud. Silica and alpha-alumina nanoparticles were synthesized using the sol-gel process and characterized through several techniques, including X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, and atomic force microscopy. The effects of silica and alumina nanoparticles on various properties of drilling mud were then measured using a perme

A laboratory experiment was carried out in the laboratories of College of Agricultural Engineering Sciences, University of Baghdad in 2017. Three factors were studied; Sorghum bicolor L. cultivars (Inqath, Rabeh and Buhoth70), primed and unprimed seed, and salt stress (0, 6, 9 and 12 dS.m−1). The aim was to improve germination and seedling growth under salt stress. The results showed significant superiority of Buhoth70 cultivar compared to others, significantly superiority of primed seed compared to the unprimed and significant negative impact as long as increasing levels of salt stress at germination ratio, plumule length, dry seedling weight and seedling vigor index. The interaction between cultivars, priming and salt stress showed that

Industrial buildings usually are designed to sustain several types of load systems, such as dead, live, and dynamic loads (especially the harmonic load produced by rotary motors). In general, these buildings require high-strength structural elements to carry the applied loads. Moreover, Reactive Powder Concrete (RPC) has been used for this purpose because of its excellent mechanical strength and endurance. Therefore, this study provides an experimental analysis of the structural behaviors of reinforced RPC beams under harmonic loads. The experimental program consisted of testing six simply supported RPC beams with lengths of 1500 mm, widths of 150 mm, and thicknesses of 200 mm under harmonic loading with varied frequencies between 1