Solar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct represents case A. A 2D, steady-state simulation model that took into account the impact of the convective flow of air circulating inside the PVT system in addition to radiative and convective heat losses from the front PV surface was developed and validated via previous tests. The results revealed that, under the same volume requirements, the application of surface zigzags is preferred for airflow rates of 0.06 kg/s or less, whereas the introduction of fins is preferred for higher airflow rates. The results also revealed that, of the three cases considered, the introduction of the fin–surface zigzag combination is the most effective and has the potential to improve the electrical and thermal efficiency by ~26% and 3%, respectively.
Child's personality development in Islam, in fact, represents the building of the Islamic community and a step on the way for the establishment of life, state, law, and civilization in accordance with the blessed Islamic principles, in order to achieve the happiness of the human being and to protect the components of society and preserve human safety. Child is the issue of interest across many years. Paying heed to childhood issues is not a recent one. The faith of these communities in the child's rights and his education, which makes a man who cherishes himself and his language and homeland.
The success of Islamic goals, the happiness of the individual and the
... Show MorePlaying is the only common language among children in every place and time, to the fact that what distinguishes the children is their quest to play and fun way innate, not acquired, which is expressed with the child really is one of the rights. And play a key entrance to the growth of the child mentally, intellectually and cognitively and not for the child emotionally and socially just. In the play the child begins to identify and classify objects and learn concepts and circulate among themselves on a linguistic basis. Activity here and play a major role in leading the linguistic development of the child in the composition has the communication skills.
The Games (especially intellectual ones) Whatever the cause of the development
... Show MoreThis research examines the phenomenon of the Arabic language repeated in the Qur'an and poetry, as some morphological formulas are valid in their uses and indications in more than one way. search).
this paper give a proof of known conditions for the existence of peridic conincidence points of continuius maps using lindemann theotem on transcendental numbers
Urban growth of cities is connected with three related problems, the first one, is the deterioration of the center, which is a mark for historical origin. The second is the emergence of city edge, which contradicts by the center. The third one is the rapid semi urbanism of the edge. Literature review showed that Baghdad historical center (Old Rusafa and Karkh) had grown in four morphological stages, during which main paths had been changed from those which were perpendicular to the river front to those parallel to it. Research problem is that “there is a knowledge gap about the direction and origin of paths within Baghdad old center, after its growth”. The first research hypothesis is, “the direction of paths within old Baghdad cen
... Show MoreThe research aims to identify the reasons that lead to asymmetry of information between economic unity administration and the parties that use accounting information such as shareholders, So, the ability to reach to the solutions that would reduce this problem, these factors have been divided into two types: the first one is the internal factors which represent the administration's desire in order to expand the self-interest of getting the profits and increase the value and competitive entity and investors to obtaining greater returns for their shares, so the second type is the external factors, which represent the failer that occurs in the laws and regula
... Show MoreResearch is a study conducted by a researcher or a group of researchers to uncover ambiguity, complete a knowledge, or define a relationship, Solve a problem, or answer a question by carefully investigating the comprehensive and in-depth examination of the evidence and evidence related to this knowledge, revealing a relationship, or solving a problem, or answering a question, to be a systematic, In evidence and evidence that reveal facts and general rules, relationships or solutions, in addition to providing knowledge Human rights are verifiable, tested and confirmed. The university research (graduate research, master's thesis, doctoral dissertation) is the most important type of research, and it is supposed to be the best one, since it
... Show MoreThe stanza in the sonnet has been defined as a set of poetic lines followed after proem
and be the same meter as that of proem in complete stanza, but in rhyme scheme different
from that meter. The couplet is defined as set of poetic lines that followed the stanza and be as
the same meter as that of stanza, but with different rhyme scheme. This definition is approved
by all specialized in field of Andalus literature and it was also proven to them that this
construction emptied of indications. This meter has endeavored to prove that that there were a
difference in denotation for meaning between the stanza and couplet. Thus, the sonneteers
have outweighed the sonnet of the blind "Tutaili" to their sonnets as they felt
Al-Yaqubi was biased in favor of Shia. May be du to his choice of source, materials. All historians as with other human beings are biased in their attitudes and preconceptions in one degree or another as well as in one direction or another.
The choice of source materials, their nature and the use made of them is an important index for measuring the achievement of ang historian.
Several specific questions arise. What sources did author use that were either unknown to or were not employed by his predecessors and contemporaries for whatever reason?
What sources are common to al- Yaqubi and his colleagues among the early Arab historians and what evidence of tendentiousness can be ascert- ained in these? To what extent can the author
Summary
The conflict between Arab and Zionist movement before 1948 was not normal dispute about certain issue or quarrel on borders, it is comprehensive conflict, this research intraduce analytical and outlook future reading about Palestine identity in time of occupation and resistance in the first studying we take the concept of identity and the fundamental relationship identity history and geography. Our research treated the contents of palest Iain and Isralian identsunder. The political, cultural and military conflict between Israil and Palestine. The research introduce analytic study of research introduce analytic study of intellectual orientation of Zionist state in order to determine the exact meaning of this identity, beca
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