تشكل الأخطار منذ القدم عائقا مهما أمام تقدم البشرية وتطورها وقد واجه الانسان منذ ان وجد على الكرة الارضية اخطارا مختلفة فالمخاطر الطبيعية كانت ولا زالت تهدد حياته وممتلكاته ، وقد كان ايضا لتقدم العلوم والتكنولوجيا ان تنوعت وازدادت المخاطر التي تواجه هذا الانسان فهو اليوم يعاني من اخطار الطاقة النووية وسقوط المركبات الفضائية والتلوث البيئي والاحتباس الحراري واخطار لم يسمع بها سابقا .

وقد كان الانسان د

The method of request is one of the important rhetorical methods used by the creator in terms of rhetorical diversification, influence, artistic aesthetics and increasing textual coherence, and we tried through a group (Which torments are inferior) by the poet Majid Al-Rubaie, to shed light on these methods and their ability, displacement, relationality, direct and advertising interactions from them, and what they broadcast From metaphorical purposes is the second image of it, after its main image and title. This cohesion and harmony between the two images is an important and influential rhetorical trend

The method of request is one of the important rhetorical methods used by the creator in terms of rhetorical diversification, influence, artistic aesthetics and increasing textual coherence, and we tried through a group (Which torments are inferior) by the poet Majid Al-Rubaie, to shed light on these methods and their ability, displacement, relationality, direct and advertising interactions from them, and what they broadcast From metaphorical purposes is the second image of it, after its main image and title. This cohesion and harmony between the two images is an important and influential rhetorical trend.

This paper presents the first data for bremsstrahlung buildup factor (BBUF) produced by the complete absorption of Y-91 beta particles in different materials via the Monte Carlo simulation method. The bremsstrahlung buildup factors were computed for different thicknesses of water, concrete, aluminum, tin and lead. A single relation between the bremsstrahlung buildup factor BBUF with both the atomic number Z and thickness X of the shielding material has been suggested.

The convolutional neural networks (CNN) are among the most utilized neural networks in various applications, including deep learning. In recent years, the continuing extension of CNN into increasingly complicated domains has made its training process more difficult. Thus, researchers adopted optimized hybrid algorithms to address this problem. In this work, a novel chaotic black hole algorithm-based approach was created for the training of CNN to optimize its performance via avoidance of entrapment in the local minima. The logistic chaotic map was used to initialize the population instead of using the uniform distribution. The proposed training algorithm was developed based on a specific benchmark problem for optical character recog

Over the past few decades, the surveying fieldworks were usually carried out based on classical positioning methods for establishing horizontal and vertical geodetic networks. However, these conventional positioning techniques have many drawbacks such as time-consuming, too costly, and require massive effort. Thus, the Global Navigation Satellite System (GNSS) has been invented to fulfill the quickness, increase the accuracy, and overcome all the difficulties inherent in almost every surveying fieldwork. This research assesses the accuracy of local geodetic networks using different Global Navigation Satellite System (GNSS) techniques, such as Static, Precise Point Positioning, Post Processing Kinematic, Session method, a

In this study, hydroxyapatite (HAP, Ca10(PO4)6(OH)2) has been prepared as bioceramic material with biological specifications useful to used for orthopedic and dental implant applications. Wet chemical processing seems to form the fine grain size and uniform characteristic nanocrystalline materials by the interstice factors controlling which affected the grain size and crystallinity in order to give good mechanical and/or constituent properties similar as natural bone. Fluorinated hydroxyapatite [4-6 wt% F, (FHA, Ca10(PO4)6(OH)2–Fx] was developed in new method for its posses to increased strength and to give higher corrosion resistance in biofluids than pure HAP moreover reduces the risk of dental caries. The phase's and functional groups

The present work aimed to study effect of (N749 & N3) dyes on TiO2 optical and electrical properties for optoelectronic application. The TiO2 paste prepared by using a doctor blade method. The samples were UV-VIS specterophometricall analyzes of TiO2 before and after immersed in dyes (N749 & N3). The results showed absorption spectra shift toward the visible region due to the adsorption of dye molecules on the surface of oxide nanoparticles. It is seen that the Eg determined to give a value of 3.3eV for TiO2 before immersing in dyes, and immersing in dyes (N749 & N3) are (1.4 &1.6 eV) respectively. The structural properties (XRD), (FTIR) and (SEM) for the sample prepared were investigated and (J-V) characteristics was stu

The human kidney is one of the most important organs in the human body; it performs many functions
and has a great impact on the work of the rest of the organs. Among the most important possible treatments is
dialysis, which works as an external artificial kidney, and several studies have worked to enhance the
mechanism of dialysate flow and improve the permeability of its membrane. This study introduces a new
numerical model based on previous research discussing the variations in the concentrations of sodium,
potassium, and urea in the extracellular area in the blood during hemodialysis. We simulated the differential
equations related to mass transfer diffusion and we developed the model in MATLAB Simu