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One of the most powerful tools for any stellar dynamics is the N-body simulation. In an N-body simulation the motion of N particles is followed under their mutual gravitational attraction. In this paper the gravitational N-body simulation is described to investigate Newtonian and non- Newtonian (modified Newtonian dynamics) interaction between the stars of spiral galaxies. It is shown that standard Newtonian interaction requires dark matter to produce the flat rotational curves of the systems under consideration, while modified Newtonian dynamics (MOND) theorem provides a flat rotational curve and gives a good agreement with the observed rotation curve; MOND was tested as an alternative to the dark matter hypothesis. So that MOND hypothesis has generated better rotation curves than Newtonian theorem. |
Polyacrylamide Solutions of different concentrations (0.2, 0.4, 0.6, 0.8, 1.0 %) of Ag nanoparticles and ZnO nanoparticles were prepared, the viscosities and surface tension were measured for all solutions, where measurements indicated an increase in these properties with increased concentration, where the relative viscosity of polyacrylamide/zinc nanoparticles increased from 1.275 to 2.243, and the relative viscosity of polyacrylamide/silver nanoparticles increased from 1.178 to 1.934. Viscosity is significant parameters during electrospinning process. While the surface tension of the polyacrylamide/zinc nanoparticles has changed from 0.0343 Nm-1 to .0.0.0 Nm-1 and changed from .0.000Nm-1 to.0.0.0 Nm-1. Also the constants KH and KK were
... Show MoreSoft red winter wheat (SRW) is characterized by high yield and relatively low protein content. In Kentucky, there is growing demand from local artisan bread bakers for regionally produced flour, requiring production of grain with increased protein content and/or strength. The objective of this two-year field experiment was to evaluate the effect of nitrogen (N) management on five cultivars of winter wheat on yield and bread baking quality traits of modern and landrace SRW cultivars (Triticum aestivum L.). All five cultivars were evaluated using two N application rates in conventional and organic production systems. All traits measured were significantly affected by the agricultural production system and N rate, although plant height
... Show MoreIntroduction: Sleep, an essential therapeutic part of human physiology, Sleep problems was widespread among students in medical colleges, and excessive stress and the pressure of holding grades can affect their sleep quality. The relationship between sleep, stress and cognition/learning is far more complex than perceived. Material and Method: Cross sectional study was conducted in Al-Kindy College of Medicine, during the period from (2022 to 2023) academic year. The electronic questionnaire was distributed among all students. Analysis of data was carried out using IBM SPSS version 24. Results: A total of (500) medical students' online surveys were analyzed from AL-Kindy College of Medicine, The highest number of participants was fro
... Show MoreBackground: Rheumatoid arthritis is an autoimmune disease that affects mainly the synovial membranes and articular structures and is characterized by chronic, systemic inflammation involving multiple joints.Being a synovial joint, the Temporomandibular Joint is subject to the same disorders affecting other synovial joints, including RA.Beside it was considered as a specific serological marker for diagnosing RA disease ,antibodies to cyclic citrullinated peptide have proven to be associated with joints destruction, though; it may play a potential role in the prediction of the disease severity. Materials and Methods: Sixty nine individuals (69) were enrolled in this study, forty nine (49) were patients diagnosed with Rheumatoid Arthritis, a
... Show MoreIn this paper ,six new mixed metal ligand complexes are reported with Cephalexin (Ceph.H)as a primary ligand and Dimethylglyoxime (DMG) as secondary ligand with metal Chloride [MCl2 .nH2O. M=Mn(II),Co(II),Cu(II),Ni(II) and Zn(II),n=0-6] ,CrCl3.6H2O.The complexes are of (1:1:1)(Metal:Ligand: Ligand) Stoichiometry.The structures of these complexes are confirmed by using FT-IR and UV- electronic spectroscopies, magnetic moments, melting points, molar conductivity measurements and the metal % analysis revealed that the complexes analyze indicates a four coordinated as (A)=[M(HDMG) (Ceph)] .M=[Ni(II)and Zn(II).Six coordinated as (B) = K2[M(DMG)(CePh)(H2O)]. M= Mn (II),Co(II) and Cu(II) and (C)=[Cr(DMG)(Ceph)]Cl2. Interestingly, the in-vitro anti
... Show MoreAtrial fibrillation is associates with elevated risk of stroke. The simplest stroke risk assessment schemes are CHADS2 and CHA2DS2-VASc score. Aspirin and oral anticoagulants are recommended for stroke prevention in such patients.
The aim of this study was to assess status of CHADS2 and CHA2DS2-VASc scores in Iraqi atrial fibrillation patients and to report current status of stroke prevention in these patients with either warfarin or aspirin in relation to these scores.
This prospective cross-sectional study was carried out at Tikrit, Samarra, Sharqat, Baquba, and AL-Numaan hospitals from July 2017 to October 2017. CHADS2
... Show MoreBackground: Bisphosphonates are potent inhibitors of osteoclastic bone resorption and widely used for the treatment of osteoporosis, and osteogenesis imperfecta in children. Clinical and experimental studies have demonstrated that Bisphosphonates delay or inhibit tooth eruption. This study tries to focus on the effect of bisphosphonate on teeth development and jaw bones growth. Materials and methods: The present study includes 65 neonatal rats during lactation period from 15 Albino Wister rats mother. Alendronate (one type of Bisphosphonates) was administrated orally (15 mg/kg) into 10 pregnant rats two times a week, while other 5 rats regard as control. Then the neonatal rats sacrificed in I, 6, 11, 16 and 21 days. The lower first molar we
... Show MoreThe effect of some environment faetor (different temperature and relative humidity) on the biology of the old world- screw worm, were studied under laboratory condition, the result showed that non of the eggs hatched at 15°c and under dried eondition which relative humidity between 20-40%, also result showed that the mature larvae needs one days to become pupa since it leaves the larval died at the temperature ranged between 25-40°C at different humidity rates. While it needs 3 days under lower temperature and different humidity to become pu^, on the other hand the results showed that either low temperature and dried condition or high temperature at different humidity rates cause non of pupa became adult. While low temperature (15-20) °c
... Show MoreThe acrylic polymer composites in this study are made up of various weight ratios of cement or silica nanoparticles (1, 3, 5, and 10 wt%) using the casting method. The effects of doping ratio/type on mechanical, dielectric, thermal, and hydrophobic properties were investigated. Acrylic polymer composites containing 5 wt% cement or silica nanoparticles had the lowest abrasion wear rates and the highest shore-D hardness and impact strength. The increase in the inclusion of cement or silica nanoparticles enhanced surface roughness, water contact angle (WCA), and thermal insulation. Acrylic/cement composites demonstrated higher mechanical, electrical, and thermal insulation properties than acrylic/silica composites because of their lowe
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