Astronomers have known since the invention of the telescope that atmospheric turbulence affects celestial images. So, in order to compensate for the atmospheric aberrations of the observed wavefront, an Adaptive Optics (AO) system has been introduced. The AO can be arranged into two systems: closedloop and open-loop systems. The aim of this paper is to model and compare the performance of both AO loop systems by using one of the most recent Adaptive Optics simulation tools, the Objected-Oriented Matlab Adaptive Optics (OOMAO). Then assess the performance of closed and open loop systems by their capabilities to compensate for wavefront aberrations and improve image quality, also their effect by the observed optical bands (near-infrared band and visible band), the shape of the telescope aperture (circular and hexagonal) and the atmospheric seeing conditions. The results showed that open-loop systems perform better than closed-loop systems at good seeing and vice versa. Also showed that closed-loop provides stability in the correction process over time, while the open-loop is a faster phase compensator
The study targets exploring the similarities and differences between Iraqi and Malaysian learners of English in refusing marriage proposals. Also, it examines the favored politeness strategies that learners use to protect their interlocutors’ face, heeding both their social distance and status. Data were gathered by a Discourse Completion Task (DCT) which contained six marriage situations. Responses were analyzed based on Beebe et al.’s (1990) refusal taxonomy and Scollon et al.’s (2012) politeness system. The findings indicated that both the Iraqi and Malaysian learners preferred the indirect refusal strategies in marriage proposals, as well as the hierarchical politeness in the form of independence strategies regardless of t
... Show MoreIn this paper, a mathematical model consisting of a prey-predator system incorporating infectious disease in the prey has been proposed and analyzed. It is assumed that the predator preys upon the nonrefugees prey only according to the modified Holling type-II functional response. There is a harvesting process from the predator. The existence and uniqueness of the solution in addition to their bounded are discussed. The stability analysis of the model around all possible equilibrium points is investigated. The persistence conditions of the system are established. Local bifurcation analysis in view of the Sotomayor theorem is carried out. Numerical simulation has been applied to investigate the global dynamics and specify the effect
... Show MoreThe study targets exploring the similarities and differences between Iraqi and Malaysian learners of English in refusing marriage proposals. Also, it examines the favored politeness strategies that learners use to protect their interlocutors’ face, heeding both their social distance and status. Data were gathered by a Discourse Completion Task (DCT) which contained six marriage situations. Responses were analyzed based on Beebe et al.’s (1990) refusal taxonomy and Scollon et al.’s (2012) politeness system. The findings indicated that both the Iraqi and Malaysian learners preferred the indirect refusal strategies in marriage proposals, as well as the hierarchical politeness in the form of independence strategies regardless of t
... Show MoreThis study was conducted in Al-Salam station for Dairy cattle/private sector, for the period from 1-11-2016 to 1-11-2017, to determine the association between BTN1A1 gene polymorphism and reproductive efficiency indicator and heat tolerance in 50 Holstein cows. The results of BTN1A1 gene analysis showed a highly significant Different (P<0.01) between genotypes of BTN1A1 gene’s genotypes AA, AB the percentage were 72.00, 28.00 % respectively. Results showed that services per conception and days open was significantly (P<0.05) affected by polymorphism of BTN1A1 gene and for cows with AA genotype, there was also a significant difference (P<0.05) between the genotypes of BTN1A1 gene for IgG concentration in calves blood who belong to mother
... Show MoreHepatitis B and C is a serious global public health problem that causes chronic liver disease and accelerates high risk of death from cirrhosis of the liver and liver cancer.
To determine the knowledge and attitude of nonmedical students at Baghdad University toward HBV and HCV infections and to find out the relationship between demographic characteristics.
The study w
Iraq's water crisis represents one of the most pressing environmental and socioeconomic challenges facing the country today. This study examines the evolution of water resource problems in Iraq through a comprehensive historical comparison between the pre-2003 period under Saddam Hussein's regime and the post-2003 era following the U.S.-led invasion and subsequent political transformation. The research employs a mixed-method approach, analyzing quantitative data on water flow rates, infrastructure development, and qualitative assessments of policy impacts across both periods. Key findings reveal that while the pre-2003 period was characterized by deliberate environmental destruction, particularly the draining of the Mesopotamian Marshes, an
... Show MoreDespite extensive investigation as biocompatible drug carriers, gelatin nanoparticles (GNPs) have not been thoroughly assessed for carrying chemically distinct cationic molecules such as acriflavine (ACF) and triethylenetetramine (TETA). In this study, we hypothesize that GNPs can effectively encapsulate ACF and TETA, forming stable delivery systems with distinct antibacterial and cytotoxic activities. ACF encapsulated in gelatin was prepared adapting desolvation technique. The procedure involved stirring of an aqueous solution of gelatin and ACF at room temperature, the pH was titrated to eight using NaOH followed by addition of ethanol. The resulting nanopart
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Foreign direct investment (FDI) has been viewed as a power affecting economic growth (EG) directly and indirectly during the past few decades. This paper reviewed an amount of researches examining the relationships between FDI and EG, especially the effects of FDI on EG, from 1994 up to 2012. The results show that the main finding of the FDI-EG relation is significantly positive, but in some cases it is negative or even null. And within the relation, there exist several influencing factors such as the adequate levels of human capital, the well-developed financial markets, the complementarity between domestic and foreign investment and the open trade regimes, etc.
The Bi2Se3 compound was synthesis by fusing initial compounds consisting of
extra pure elements in stoichiometric ratio from elements compound, charged inside
quartz ampoule. The crystal growth of Bi2Se3 carried out using Brighaman technique
process from melting f (Bi+Se ) at temperature of 810 ºC for about 48 hrs. Single crystal
of Bi2Se3 has been grown in direction (211) after slow cooling on account of heat
gradient to zone furnaces at cooling rate (1-3) C/hr. The structure study of the compound
was determined by x-ray diffraction technique, which it has bismuthinite structure and
orthorhombic unit cell with lattice parameters of a=10.2678 Å, b=11.2392 Å and
c=5.1737 Å