This paper contains an equivalent statements of a pre-  space, where  are considered subsets of with the product topology. An equivalence relation between the preclosed set  and a pre-  space, and a relation between a pre-  space and the preclosed set  with some conditions on a function  are found. In addition, we have proved that the graph  of  is preclosed in if  is a pre-  space, where the equivalence relation  on  is open.

     On the other hand, we introduce the definition of a pre-stable ( pre-stable) set by depending on the concept of a pre-neighborhood, where we get that every stable set is pre-stable. Moreover, we obtain that

The 3D electro-Fenton technique is, due to its high efficiency, one of the technologies suggested to eliminate organic pollutants in wastewater. The type of particle electrode used in the 3D electro-Fenton process is one of the most crucial variables because of its effect on the formation of reactive species and the source of iron ions. The electrolytic cell in the current study consisted of graphite as an anode, carbon fiber (CF) modified with graphene as a cathode, and iron foam particles as a third electrode. A response surface methodology (RSM) approach was used to optimize the 3D electro-Fenton process. The RSM results revealed that the quadratic model has a high R2 of 99.05 %. At 4 g L-1 iron foam particles, time of 5 h, and

الكتابة عن الأندلس بعد تسليم مدينة غرناطة يحمل في ثناياه ألم كبير، لأن الأندلسيين عاشوا تجربة إنسانية قاسية سببها الأساس غياب التسامح الديني والعدالة الاجتماعية، الأمر الذي دفعهم للثورة مطالبين بحقوقهم التي نصت عليها معاهدة تسليم المدينة. فقد  عاش أولئك حياة صعبة ، فكانوا صورة  للصراع  بين حضارتين  الإسلامية والغربية ،  ويمكن تلمس ذلك الصراع من خلال دراسة ثوراتهم ضد السلطة الحاكمة التي يبدو من تتبع أح

Receipt date:2/17/2021 acceptance date:3/16/2021 Publishing date:12/31/2021

This work is licensed under a Creative Commons Attribution 4.0 International License.

Objective: This paper investigates the contradictions in the decision-making process of the United States, which historically proven to be successful policies in the short term, but in the long term proven to be wanting and failure. Methodology: The paper uses descriptive, historical, comparative method. A

There are great figures in our nation, who are famous for their encyclopedia in their sciences, and their fame spreads across the horizons for what they presented to their religion and nation.
So they became torches of guidance, advocates of goodness, and treasuries of knowledge until God inherits the earth and those on it.
Among these imams is Imam al-Qurtubi, who died in the year (671 AH), after whom he left a great legacy of valuable books, including this one, which is the subject of my research, his valuable interpretation (Al-Jami’ Li Ahkam Al-Qur’an). Taking from him and his approach in interpreting the verses of judgment, following the method of extrapolation, investigation and deduction to know his style, which he used

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Continuous escalation of the cost of generating energy is preceded by the fact of scary depletion of the energy reserve of the fossil fuels and pollution of the environment as developed and developing countries burn these fuels. To meet the challenge of the impending energy crisis, renewable energy has been growing rapidly in the last decade. Among the renewable energy sources, solar energy is the most extensively available energy, has the least effect on the environment, and is very efficient in terms of energy conversion. Thus, solar energy has become one of the preferred sources of renewable energy. Flat-plate solar collectors are one of the extensively-used and well-known types of solar collectors. However, the effectiveness of the coll

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