The present work presents design and implementation of an automated two-axis solar tracking system using local materials with minimum cost, light weight and reliable structure. The tracking system consists of two parts, mechanical units (fixed and moving parts) and control units (four LDR sensors and Arduino UNO microcontroller to control two DC servomotors). The tracking system was fitted and assembled together with a parabolic trough solar concentrator (PTSC) system to move it according to information come from the sensors so as to keep the PTSC always perpendicular to sun rays. The experimental tests have been done on the PTSC system to investigate its thermal performance in two cases, with tracking system (case 1) and without trackin

The present work represents a theoretical study for the correction of spherical aberration of an immersion lens of axial symmetry operating under the effect of space charge, represented by a second order function and preassigned magnification conditions in a focusing of high current ion beams. The space charge depends strongly on the value of the ionic beam current which is found to be very effective and represents an important factor effecting the value of spherical aberration .The distribution of the space charge was measured from knowing it's density .It is effect on the trajectory of the ion beam was studied. To obtain the trajectories of the charged particles which satisfy the preassined potential the axial electrostatic potential w

Conclusion The observation of the phenomenon of structural evolution of the international system and its instability on a particular situation, by its transition from unipolar to polarity to bipolarism and then to unilateralism in the early 1990s led by the United States, and to the present moment, To say that the structure by which the hierarchy of superpowers or the regime is directed in terms of its various capacities that qualify it, and with the consent of the rest of the States directing the regime to lead and lead the world's first place, has no direct relation to the stability of this system, I hope other more influential in its stability. The structure of the new international order will be completely different in terms of the r

Abstract of the research:

     This research sheds light on an important phenomenon in our Arabic language, which is linguistic sediments, and by which we mean a group of vocabulary that falls out of use and that native speakers no longer use it, and at the same time it happens that few individuals preserve the phenomenon and use it in their lives, and it is one of the most important phenomena that  It should be undertaken and studied by researchers;  Because it is at the heart of our huge linguistic heritage, as colloquial Arabic dialects retain a lot of linguistic sediments, and we usually find them at all levels of language: phonetic, banking, grammatical and semantic.  In the

Advertisement is one of the Media most efficient persuasive communicative activities designed to marketing different ideas and products with the aim of influencing consumers' perception of goods and services. The present study sheds light on the most prominent rhetorical devices that constitute the persuasive structure of the Hebrew advertisements published in various media outlet. The study is conducted by means of analyzing the linguistic structure of the advertising texts and according to the analytic and descriptive approach to know the characteristics and the functions of the oratorical devices used in the advertising industry. The research elucidates that most of the advertisements are written in slang language, and this is due to th

The person who wants to learn. The history of Bab’is will notice a very
starnge phenomenon that they (Babis and Baha’is) resort to visions to prove their
delusion.
The believers usually reach to each other by their visions. This phenomenon
are shared among them from Al- Ahsa’ai time till the last phase of their propaganda
which is the Baha’is propaganda, and this is due to their ignorance and under
development in doctrine of islam which was widespread in Iran and the Islamic world.
The whole secrets of Babis and Baha’is movement were restricted among
particular group, most of them were Al- Rashti’s students and knew the basic
principles of their movement which deperding or (the principles) declarati

Presupposition in Fitzgerald the Rough Crossing

The principle in the language is that each word has one meaning. This is because the purpose of language development is for understanding, understanding, and communication between people. The language is sounds with which each people expresses their Arabic language did not stop at this point, but rather needed another next stage or to convey additional features or characteristics that would qualify it. To be the language of the Qur’an and revelation, and capable of carrying this heavy burden.

It is the dynamic tension between the relatively fixed built environment and the constantly changing in social life that determines the nature of urban spaces belonging to different historical periods, and considered as a tool for diagnosing transformations in urban spaces, that’s why, the characteristics of urban space became unclear between positive spaces and negative spaces, so emerged the need to study contemporary urban space belonging to the current period of time and show the most important transformations that have occurred in contemporary urban space to reach urban spaces that meet the current  life requirements. Therefore, the research dealt with a study of the characteristics of contemporary urban space and the most pr