In this work, an estimation of the key rate of measurement-device-independent quantum key distribution (MDI-QKD) protocol in free space was performed. The examined free space links included satellite-earth downlink, uplink and intersatellite link. Various attenuation effects were considered such as diffraction, atmosphere, turbulence and the efficiency of the detection system. Two cases were tested: asymptotic case with infinite number of decoy states and one-decoy state case. The estimated key rate showed the possibility of applying MDI-QKD in earth-satellite and intersatellite links, offering longer single link distance to be covered.

This study investigates the challenges encountered by first-grade intermediate students in learning the Arabic language. It aims to identify specific obstacles that hinder language acquisition and proficiency among this demographic. Through qualitative and quantitative methods, including surveys and interviews with students, teachers, and parents, the research highlights key issues such as limited vocabulary, difficulties in grammar, lack of engagement with the material, and inadequate teaching resources. The findings reveal a complex interplay between cognitive, social, and educational factors that contribute to these challenges. The study underscores the need for targeted interventions, such as enhanced pedagogical strategies and improved

In this research, the effect of adding two different types of reinforcing particles was investigated, which included: nano-zirconia (nano-ZrO₂) particles and micro-lignin particles that were added with different volume fractions of 0.5%, 1%, 1.5% and 2% on the mechanical properties of polymer composite materials. They were prepared in this research, as a complete prosthesis and partial denture base materials was prepared, by using cold cure poly methyl methacrylate (PMMA) resin matrix. The composite specimens in this research consist of two groups according to the types of reinforced particles, were prepared by using casting methods, type (Hand Lay-Up) method. The first group consists of PMMA resin reinforced by (nano-ZrO

In this paper the queuing system (M/Er/1/N) has been considered in equilibrium. The method of stages introduced by Erlang has been used. The system of equations which governs the equilibrium probabilities of various stages has been given. For general N the probability of j stages of service are left in the system, has been introduced. And the probability for the empty system has been calculated in the explicit form.

New complexes were synthesized with Schiff base tetradentate ligand (L). The ligand was synthesized by the condensation reaction of the dimedone with 2-hydroxybenzohydrazide. The formula of complexes [M(L) (H2O)2].Cl2, where M represents Mn(II), Ni(II) Cu(II), [Co(L)Cl.H2O]Cl and [Zn(L)(H2O)2]Cl2.2H2O. The ligand was identified using m.p., UV-Vis, FT-IR, Mass, 1H-NMR, and C.H.N. These complexes were characterized using techniques including infrared, UV-Vis absorption, magnetic susceptibility, molar conductivity, elemental analyses, thermogravimetric analysis (TGA), chloride content determination using Mohr’s method, and atomic absorption spectroscopy. The measurements revealed that the complexes are electrolytic. FT-IR results dem

           In the nineteenth century, a new type of cities appeared, known as new cities located on the edges of major cities, and these cities began to  decentralization, urban studies turned to this type of cities to find out the most important reasons for the emergence of new cities and find out what those cities will become . Therefore, we will discuss in this research how the urban emergence of these cities (edge cities) occurs, so the research formulates its problem : The need to know the stages that edge cities go through, ending with their emergence, and the mechanisms that cities take within their context  ( regeneration or adaptation ), Assuming that edge cities are a

Obesity is disorder in a foremost nutritional health it’s developed with countries developing. Also is known as increasingin fat accumulation that lead toproblem in health, besidesmay coin one of the reasons lead toloss of life,the obesity not effect on adults just but effect onoffspringand juveniles. In some ofinhabitants the incidence of obesity is superior in female than in male; on the other hand, the variation degree of the between the genderdifferby country.Obesity is generally measured by body mass index and waist circumference, Obesity are classified according to body mass index into:Pre obesity sort 1 : (25 - 29.9) kg/m2, Obesity sort 2 : (30 - 34.9 kg/m2) and extreme obesity sort 3: (40 kg/m2) or greater. Obesity is described by

The majority of statisticians, if not most of them, are primarily concerned with the theoretical aspects of their field of work rather than their application to the practical aspects. Its importance as well as its direct impact on the development of various sciences. Although the theoretical aspect is the first and decisive basis in determining the degree of accuracy of any research work, we always emphasize the importance of the applied aspects that are clear to everyone, as well as its direct impact on the development of different sciences. The measurements of public opinion is one of the most important aspects of the application of statistics, which has taken today, a global resonance and has become a global language that everyone can