عرف الإنسان اللؤلؤ منذ عصورما قبل التاريخ ، حيث كان يجمعه من الأصداف التي كانت تلقي بها الأمواج على الساحل . و لم تُمارس مهنة الغوص إلا في مرحلة لاحقة لم يحدد تاريخها .

In terms of each party's contribution to the common venture, partnership felt in several categories. It would be a complete partnership, that is, one in which all partnership, both capital and service; It could be an arrangement like the commenda (Arabic : Mudãraba , muqãraba , girãd) in which one party supplied the capital and the other service .
In Malikite and Hanaifite Law, It would take the form of a labor partnership, that is, one in which the only investment on the part of all its members was their skill or labor. In this last category of partnership, the captil itself considered solely or primarily of the labor of the partners.

The Arabs took care of the Arabic language, collected it, and set standards governing it; This is for fear of melody, in order to preserve the language of the Noble Qur’an from distortion, after many of those who are not fluent in Arabic entered Islam; There were many reasons for setting linguistic standards, but although scholars set these standards, we see them often deviate from them, as well as the language’s departure from these restrictions that they set, because language cannot be restricted, as it is subject to the law of use.

The Arabs took care of the Arabic language, collected it, and set standards governing it; This is for fear of melody, in order to preserve the language of the Noble Qur’an from distortion, after many of those who are not fluent in Arabic entered Islam; There were many reasons for setting linguistic standards, but although scholars set these standards, we see them often deviate from them, as well as the language’s departure from these restrictions that they set, because language cannot be restricted, as it is subject to the law of use

شيد الفكر العربي المعاصر تحولات عدة فرضتها بعض التيارات الفكرية والفلسفية الغربية، وأثرت في تكوينه وتحديد اتجاهاته، فضلا عن التحديات التي بات لزاما عليه ان يتعامل معها ويمكن رد هذه التحديات الى عدة عوامل داخلية وخارجية أنتجت عدة تيارات تناولت موضوع العقلانية في الفكر العربي المعاصر، لعل أبرزها التيار الاصلاحي، التيار الليبرالي، والتيار العقلي النقدي

The Arabic medicine books have emphasized that the Arabic Pediatricians in their scientific career ,who searched in Various aspects concerns with pediatric , as well as that some  medical results and phenomena emphasized some data related to this subject . Which operates at the present time attention and concern towards human and in public and towards Pediatricians in special.

This research contained from an introduction that interpreted the Arabic medical heritage in progressing medicines in Europe then it mentioned the prominence  Arabic pediatricians . the researcher depended on references and sources which will the reader had found through research.

The present study aimed to investigate the effects of level pH and the growth phases of Coelastrella saipanensis on Chlorophyll a,b, total, and Carotene. The algae were cultured in BG11 media and grown at different pH levels. We measured chlorophyll a, b, total chlorophyll, growth phases, and carotene concentrations. The results showed that at pH 8.5, the measurements of photosynthetic pigments-chlorophyll a, Chlorophyll b, and the total chlorophyll (0.183, 0.268, and 0.433 mg L-1, respectively). The highest values of chlorophyll a (0.185 mg L-1), and b (0.339 mg L-1), and the total chlorophyll (0.492 mg L-1) were recorded in the stationary phase. In addition, the study found that at pH 8.5 and the beginning of the stationary phase,

The chemical bath deposition technique (CBD) is considered the cheapest and easiest compared with other deposition techniques. However, it is highly sensitive to effective parameter deposition values such as pH, temperature, and so on. The pH value of the reaction solution has a direct impact on both the nucleation and growth rate of the film. Consequently, this study presents a novel investigation into the effect of a precise change. in the pH reaction solution value on the structural, morphological, and photoresponse characteristics of tin monosulphide (SnS) films. The films were grown on a flexible polyester substrate with pH values of 7.1, 7.4, and 7.7. The X-ray diffraction patterns of the grown films at pH 7.1 and 7.4 confirmed

Background: The main drawback of soft lining materials was that they debonded from the denture base after a certain period of usage. Therefore, the purpose of this research was to determine the impact of oxygen and argon plasma treatment on the shear bonding strength of soft liners to two different kinds of denture base materials: conventional acrylic resin and high impact acrylic resin. Materials and Methods: Heat cure conventional and high impact acrylic blocks (40 for each group) were prepared. A soft liner connected the final test specimen of two blocks of each acrylic material. Shear bond strength (SBS) was assessed using universal testing machine. Additional blocks were also prepared for analyzing Vickers microhardness, contact ang

The Korteweg-de Vries equation plays an important role in fluid physics and applied mathematics. This equation is a fundamental within study of shallow water waves. Since these equations arise in many applications and physical phenomena, it is officially showed that this equation has solitary waves as solutions, The Korteweg-de Vries equation is utilized to characterize a long waves travelling in channels. The goal of this paper is to construct the new effective frequent relation to resolve these problems where the semi analytic iterative technique presents new enforcement to solve Korteweg-de Vries equations. The distinctive feature of this method is, it can be utilized to get approximate solutions for travelling waves of