The present work aimed to make a comparative investigation between three different ionospheric models: IRI-2020, ASAPS and VOACAP. The purpose of the comparative study is to investigate the compatibility of predicting the Maximum Usable Frequency parameter (MUF) over mid-latitude region during the severe geomagnetic storm on 17 March 2015. Three stations distributed in the mid-latitudes were selected for study; these are (Athens (23.50o E, 38.00o N), Jeju (124.53o E, 33.6o N) and Pt. Arguello (239.50o W, 34.80o N). The daily MUF outcomes were calculated using the tested models for the three adopted sites, for a span of five-day (the day of the event and two days preceding and following the event day). The calculated datasets were co

ABSTRACT Background: Improving the properties of heat- cured and self-cured acrylic resin have been studied by many researchers. However, little studies concerned with visible light cured resin (VLCR) improved through addition of nanofiller are available. The purpose of this study was to evaluate some properties of (VLCR) after addition of SiO2 nanofiller. Materials and Methods: SiO2 nanofiller were added to (VLCR) tray material after being dissolved in tetrahydrofuran (THF) solvent. According to the pilot study 2% SiO2 nanofiller addition exhibited better properties than the other percentages (1%, 3%). The main study conducted involved (100) specimens divided into 5 groups according to the test included. (20) Specimens were selecte

Background: Pit and fissure sealant have been considered an outstanding adjunct to oral health care in the decrease of occlusal caries onset and low progression. The aims of this in vitro study were to evaluate the marginal microleakage of three different types of fissure sealants (SDI, Tg and tetric N-flow) by time interval, one day and 45 days, in the presence or absence of bonding agent among maxillary and mandibular teeth. Materials and methods: Seventy two sound human maxillary and mandibular first premolar teeth were collected which were free from obvious carious lesions. The teeth were randomly divided into two main equal groups, group (1) and group (2), each group consists of (36) teeth involving equal numbers of maxillary and mandi

الغرض - تعتمد هذه الدراسة على المنهج الوصفي التحليلي من خلال جمع البيانات اللازمة وتحليلها، كون هذا المنهج يركز على استطلاع الآراء لعينة البحث وتوجهاتها ، وتهدف إلى تطوير نموذج يدرس العلاقة بين خلق المعرفة والبراعة التنظيمية في المصارف الخاصة العراقية والتحقق من صحته تجريبياً. التصميم / المنهجية / المدخل- تم إجراء مسح عبر استمارة استبيان لجمع البيانات من عينة من (113) مدير من مصارف تجارية خاصة بالإضافة إلى ذلك ا

Time series is an important statistical method adopted in the analysis of phenomena, practices, and events in all areas during specific time periods and predict future values ​​contribute to give a rough estimate of the status of the study, so the study aimed to adopt the ARIMA models to forecast the volume of cargo handled and achieved in four ports (Umm Qasr Port, Khor Al Zubair Port, Abu Flus Port, and Maqal Port(, Monthly data on the volume of cargo handled for the years (2006-2018) were collected (156) observations. The study found that the most efficient model is ARIMA (1,1,1).

The volume of go

Abstract

        This research aims to evaluate the application of the inspectors general of global indicators offices according to the axles (leadership, strategy and planning, employees, partners and resources, process management) and through the assumption main research which states that (there is an application for global indicators to evaluate performance in the offices of the ministries under study) which are subdivided into five sub-hypotheses according to the classification and division of the five axes of the checklist.

The researchers have taken refuge in the process of assessing the performance of the check list which included global i

Anumerical solutions is presented to investigate the effect of inclination angle (θ) , perforation ratio (m) and wall temperature of the plate (T_w) on the heat transfer in natural convection from isothermal square flat plate up surface heated (with and without concentrated hole). The flat plate with dimensions of (128 mm) length × (64 mm) width has been used five with square models of the flat plate that gave a rectangular perforation of (m=0.03, 0.06, 0.13, 0.25, 0.5). The values of angle of inclination were (0^o, 15^o 30^o 45^o 60^o) from horizontal position and the values of wall temperature (50^oC, 60 ^oC, 70 ^oC, 90 ^oC, 100^o<

The current study aims to overcome the conflicts facing the company in its way of staying and continuing to maintain its performance excellent in light of the intense competition, which made it seek to find strong ways and links with its customers through electronic communication using electronic platforms, and this put confidence and safety in The place of suspicion and fear of not fulfilling credibility or violating the privacy, so this research comes to answer about the question:  “Can the company achieve an excellent performance by relying on the customer's electronic confidence?”.

The study followed the descriptive and analytical approaches by providing a virtual model and testing the zero hypotheses, which stipulat

In the present research synthesis and study of biological activity a series of new polymers modified of chitosan with compounds containing azo group. Beginning diazonium salt produced from 3,3'-dimethyl-[1,1'-biphenyl]-4,4'-diamine reacted with concentrated HCl acid and sodium nitrite. The coupling reaction between diazonium salt with substituted aromatic aldehyde to produce Azo derivatives )1-6(. Azo Schiff bases Chitosan )7-12( were synthesized by condensation of Chitosan with Azo derivatives )1-6( in ethanol with some drops of glacial acetic acid. The structural modifications of Chitosan ring (linked to a bioactive azo moiety) were expected to give new derivatives )7-12( with a diverse range of biological functions. These compounds' st

 في البحث الحالي تم تحضير ودراسة النشاط الحيوي لسلسلة من البوليمرات الجديدة المحورة  من الكيتوسان مع مركبات تحتوي على مجموعة الآزو. في البداية تم تحضير ملح الديازونيوم من  تفاعل  3,3'-dimethyl-[1,1'-biphenyl]-4,4'-diamine مع حامض الهيدروكلوريك المركز ونتريت الصوديوم .ثم تفاعل  الازدواج بين ملح  الديازونيوم مع الديهايدات اروماتية معوضة  لإنتاج مشتقات الازو (1-6). ازو شف بيس كيتوسان((12-7 والتي حضرت من تفاعل الكيتوسان مع مشتقات