Laser cleaning of materials’ surfaces implies the removal of deposited pollutants without affecting the material. Nanosecond Nd:YAG pulsed laser, operating at 1064 nm and 532nm, was utilized. Different laser intensities and number of pulses were used on metallic and non-metallic surfaces under O2 and Ar environments to remove metal oxide and crust. Cleaning efficiency was studied by optical microscope. The results indicated the superiority of 1064 nm over the 532 nm wavelength without any detectable damage to materials’ surfaces. Marble cleaned in Oxygen gas environment was better than in Ar gas.
High-intensity laser-produced plasma has been extensively investigated in many studies. In this demonstration, a new spectral range was observed in the resulted spectra from the laser-plasma interaction, which opens up new discussions for new light source generation. Moreover, the characterizations of plasma have been improved through the interaction process of laser-plasma. Three types of laser were incorporated in the measurements, continuous-wave CW He-Ne laser, CW diode green laser, pulse Nd: YAG laser. As the plasma system, DC glow discharge plasma under the vacuum chamber was considered in this research. The plasma spectral peaks were evaluated, where they refer to Nitrogen gas. The results indicated that the
... Show MoreThin films of microcrystalline and nanocrystalline -silicon carbide and silicon, where deposited on glass substrate with substrate temperature ranging from 350-400C, with deposition rate 0.5nm per pulse, by laser induced chemical vapor deposition. The deposition induced by TEACO2 laser. The reactant gases (SiH4 and C2H4) photo decompose throughout collision associated multiple photon dissociate. Such inhomogeneous film structure containing crystalline silicon, silicon carbide and amorphous silicon carbide matrix, give rise to a new type of material nanocrystalline silicon carbide in which the optical transmittance is governed by amorphous SiC phase while nanocrystalline grain are responsible for the conduction processes. This new m
... Show Moreللشعب العربي ولع عميق و ميل شديد إلى الأسفار و الإنتقال من بلد إلى آخر ، لا تثنيهم عن ذلك صحارى واسعة و لابحار شاسعة أو مشاق عنيفة . و قد توارثوا هذا الميل منذ زمن قديم فأوغلوا في قارة آسيا و أفريقيا و أوربا وغيرها . و شقت سفنهم الخليج العربي و المحيط الهندي و البحر المتوسط و بحار اخرى . و لعل هذا الميل إلى الأسفار و الولع بالاغتراب قد عبًر عن نفسه بصورة أدبية في قصص السندباد و بصورة فعلية برحلة إبن جبير و رحلة إبن
... Show MoreOld Iraq includes the first experiences in establishing the first residential settlements in the Mesopotamian, and model villages designed and the pulp units in it and their natural matter, that made it perennial, and construction continues until now with it. These experiences were the basis for the emergence of the Iraqi civilization and thus the world and the beginning of writing, trade and the religions of the divine since before history, and then the Sumerian, Babylonian and Assyrian civilizations, and their villages that formed the Fertile Crescent.
There is a lack of knowledge and disregard for the distant and near history of Iraq in the field of rural housing, despite Iraq's leadership in this field, with the aim of the re
... Show MoreAbstract
Praise be to God, Lord of the Worlds, and prayers and peace be upon the most honorable of creation, Muhammad, whom God sent as a mercy to the worlds, and his infallible, pure, and pure family, and his faithful companions
I did not find anyone who studied stylistic structures except for one study, which is (The Literature of Imam Al-Jawad (peace be upon him), a stylistic study by the student Mina Reda Kazem, a master’s thesis), and it did not address the Hadi and the military men (peace be upon them) as the text of those texts. Coherently complementing each other.
I decided to stand by this heritage as a single text in a uniform period of time approximately from the year 195-260 AH, some
... Show MoreThis research is the subject of "Domination and Motivation in the Sculptures of Mona the Saudi" to the study of an accomplished Arab sculptor with its varied sculptural activity between the works of the exhibition and the works of the squares, as well as its distinguished place among the contemporary Arab sculptors. This research is divided into four chapters:
The first chapter deals with the general methodological framework of the research in terms of the research problem which is focused on the question: What is the hegemony and motivation in the sculptures of Mona Saudi? The importance of research and the need for it, including the technical scientific material concerned with the sculptural achievement of t
... Show MoreStereolithography (SLA) has become an essential photocuring 3D printing process for producing parts of complex shapes from photosensitive resin exposed to UV light. The selection of the best printing parameters for good accuracy and surface quality can be further complicated by the geometric complexity of the models. This work introduces multiobjective optimization of SLA printing of 3D dental bridges based on simple CAD objects. The effect of the best combination of a low-cost resin 3D printer’s machine parameter settings, namely normal exposure time, bottom exposure time and bottom layers for less dimensional deviation and surface roughness, was studied. A multiobjective optimization method was utilized, combining the Taguchi me
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