حضيت القيادة باهتمام كبير من قبل الباحثين ودورها الإيجابي في التأثير على الموظفين ونجاح المنظمات، في الآونة الأخير بدأت الدراسات تركز على الجانب المظلم للقيادة وتأثيرها على التابعين وبيئة العمل، وقد تم تحديد القيادة السامة بأنها أخطر الأساليب القيادية التي تتسبب بتكاليف مادية ومعنوية على المنظمات بمختلف جوانبها، ان القيادة السامة تأثر على دوافع المرؤوسين وقدرتهم على انجاز المهام، ورغبتهم في الاستمرار في العمل، ويتبع القادة السامين أساليب الترهيب والاقصاء والتنمر والتهديد والتهميش للمرؤوسين، مما يؤثر سلبا على رفاهيتهم وصحتهم النفسية، لذا أصبح من الضروري على المنظمات وضع آليات مناسبة لمنع انتشار مثل هذه السلوكيات السامة المدمرة للفرد والمنظمة، وعلية يهدف البحث الحالي للتعرف على القيادة السامة من خلال مراجعة اهم ادبياتها، واستعراض أهم السلوكيات والصفات التي يتسم بها القائد السام، ومدى تأثيرها على الاتباع وبيئة المنظمة.
Orbital varices are vein dilations in the orbit presenting various symptoms. This scoping review synthesizes existing evidence on their epidemiology, clinical features, and treatment efficacy.
Literature was reviewed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and Scopus were searched until April 31, 2024, for articles on clinically diagnosed ocular varices detailing diagnostic methods, treatments, and outcomes. Exclusions were reviews, animal studies, and incomplete case reports. Data on study characteristics, diagnosis, management, and o
Many researchers used different methods in their investigations to enhance the heat transfer coefficient, one of these methods is using porous medium. Heat transfer process inside closed and open cavities filled with a fluid-saturated porous media has a considerable importance in different engineering applications, such as compact heat exchangers, nuclear reactors and solar collectors. So, the present paper comprises a review on natural, forced, and combined convection heat transfer inside a porous cavity with and without driven lid. Most of the researchers on this specific subject studied the effect of many parameters on the heat transfer and fluid field inside a porous cavity, like the angle of inclination, the presenc
... Show MoreThe objective of this review was to describe the COVID-19 complications after recovery.
The researchers systematically reviewed studies that reported post-COVID-19 complications from three databases: PubMed, Google Scholar and the World Health Organization (WHO) COVID-19 database. The search was conducted between 21 November 2020 and 14 January 2021. Inclusion criteria were articles written in English, with primary data, reporting complications of COVID-19 after full
This review explores the Knowledge Discovery Database (KDD) approach, which supports the bioinformatics domain to progress efficiently, and illustrate their relationship with data mining. Thus, it is important to extract advantages of Data Mining (DM) strategy management such as effectively stressing its role in cost control, which is the principle of competitive intelligence, and the role of it in information management. As well as, its ability to discover hidden knowledge. However, there are many challenges such as inaccurate, hand-written data, and analyzing a large amount of variant information for extracting useful knowledge by using DM strategies. These strategies are successfully applied in several applications as data wa
... Show MoreCarbon-fiber-reinforced polymer (CFRP) is widely acknowledged as a leading advanced material structure, offering superior properties compared to traditional materials, and has found diverse applications in several industrial sectors, such as that of automobiles, aircrafts, and power plants. However, the production of CFRP composites is prone to fabrication problems, leading to structural defects arising from cycling and aging processes. Identifying these defects at an early stage is crucial to prevent service issues that could result in catastrophic failures. Hence, routine inspection and maintenance are crucial to prevent system collapse. To achieve this objective, conventional nondestructive testing (NDT) methods are utilized to i
... Show MoreUltra-High Temperature Materials (UHTMs) are at the base of entire aerospace industry; these high stable materials at temperatures exceeding 1600 °C are used to manage the heat shielding to protect vehicles and probes during the hypersonic flight through reentry trajectory against aerodynamic heating and reducing plasma surface interaction. Those materials are also recognized as Thermal Protection System Materials (TPSMs). The structural materials used during the high-temperature oxidizing environment are mainly limited to SiC, oxide ceramics, and composites. In addition to that, silicon-based ceramic has a maximum-use at 1700 °C approximately; as it is an active oxidation process o