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Effective working parameters of laser micro-/nano-machining
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Modern emerged technologies impose development and fabrication of miniatur-ized parts and devices in the micro- and nano-scale. Producing micro- and nano-featured structures requires nonconventional machining processes where con-ventional machining processes such as grinding, milling and eroding have failed. New emerging processes, such laser machining processes, are still fraught with almost invincible processes. Micro-/nano-machining are the pro-cesses of producing parts, microsystems or features at a scale of a few microm-eters and less than one hundred nanometers, respectively. Precise cutting and clean material removal accompanied with a negligible heat affected zone (HAZ), which are usually the characteristics of laser ablation, have opened a wide door for the evolution of remarkable technologies. This has been demonstrated by applications in different fields such as medicine, biotechnology, materials pro-cessing, microelectromechanical systems, electronics and communications. The continuous development in laser technology in terms of ultra-short pulse width, short wavelength and optics technologies has reduced the drawbacks of diffrac-tion-limited processing accuracies. Laser micro-/nano-machining requires the attainment of high fluence and short interaction time to achieve ablation pro-cesses in nanofabrication and structuring of different materials. To conduct the optimum desired machining process, it is important to integrally consider a number of laser beam and working parameters. Laser wavelength, beam mode, minimum attainable spot size, peak power, pulse duration, pulse repetition rate and scanning speed are some of the important considerations. Manipulating those parameters is crucial for ideal laser ablation represented by yielding the highest resolution of machining with the least lateral dimensions, acceptable depth and minimal or no melt at the edges. The assembly of laser beam delivery and focusing system with an automation system are the essential factors for workpiece positioning and obtaining the desired dimensions. The objective of this chapter is to review the effective parameters associated with laser machin-ing processes that affect the dimensions and quality of laser machining at the micro-/nano-scales in a simple presentation. The review is supported by demonstrating laser processing techniques applied in the field of micro-/nano-machining such as mask, interferometric and scribing techniques.

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
THE STATIC ANALYSIS OF COMPOSITE AIRCRAFT WINGBOX STRUCTURE
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In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.

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Publication Date
Mon Jan 13 2025
Journal Name
Al–bahith Al–a'alami
THE USE OF EMBEDDED ADVERTISEMENTS IN FOREIGN MOVIES
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Embedded advertisement constitutes a special kind of communication. As it performs many important roles such as giving information, highlighting the value of the product, and urging the target consumer to buy it by influencing his/ her behavior using an attractive manner of mind and conscience. Both cinema and television are the most prominent and powerful advertising media that enjoy the interest of all audiences and capture most of the advertising spending. As advertisers have paid attention to the importance of indirectly incorporating their products into content that the audience loves and is keen to follow, since the actual impact lies in the inclusion of the product within content that the audience appeals to. Hence, this leads to

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Publication Date
Sat Sep 01 2018
Journal Name
Alustath Journal For Human And Social Sciences
Critical Discourse Analysis of Donald Trump's Inaugural Speech
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       Political speeches are represented in different shapes as political forum, events or as inaugural speech. This research critically analyzes the inaugural Speech of the President Donald Trump which was delivered on 20th ,January, 2017 from the site<www.cnn.com> retrieved on 10th ,May,2017. The objectives of the study are: First: classifying and discussing well known micro structures (linguistic feature) of the speech, and second: classifying the macro structures i.e. the delivered political inaugural speech  in which he includes social structures. To reach to the objectives of the study, the researcher will adopt Norman Fairclough’s three dimensional Analytical Model(

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Publication Date
Mon May 15 2023
Journal Name
Iraqi Journal Of Science
Histopathological Effects of Cadmium Chloride on Barbus sharpeyi
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The present study including determined pathological changes in Barbus sharpeyi, as
well as description behavior and growth of bunni fish by used 180 fingerlings, Fish
were distributed randomly upon four treatments in addition to control group. First
treatment (T1) contained cadmium 0.093mg/L with changing water and added cadmium
continuously, the second treatment (T2) contained cadmium 0.093mg/L with changing
water without adding cadmium, third treatment (T3) contained cadmium 0.046mg/L
with changing water and adding cadmium continuously, fourth treatment (T4) contained
cadmium 0.046mg/L with changing water without adding cadmium. In order to estimate
LC50 used 120 fingerlings of fish B. sharpeyi, were exposed to

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Publication Date
Sun Dec 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Production of Methyl Ethyl Ketone from N-Butane
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Publication Date
Sun Mar 12 2017
Journal Name
Al-academy
the director and the technique of theatrical extemporization
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Extemporization is the ability of the actor to reflect his internal being. It gives a sort of confidence and an ability to show the personal countenance of the role away from tension and rigidity. By extemporization, it is possible to deal with and criticize the real living life so it is an intellectual, emotional, sensual, and perceptive process connected with the psychological energy and the emotional memory and all this goes under the control of the director and his instigations and instructions depending on what the text involves of intellectual, social and psychological motivators so it primarily depends on talent, chance and discussion. The research involves four chapters; the first contains the problem

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Publication Date
Wed Sep 30 2009
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Reducing the evaporation of stored Iraqi crude oil
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In order to reduce the losses due to evaporation in the stored crude oil and minimizing the decrease in °API many affecting parameters were studied (i.e. Different storage system, namely batch system with different types of storage tanks under different temperatures and:or different pressures). Continuous circulation storage system was also studied. It was found that increasing pressure of the inert gas from 1 bar to 8 bar over the surface of the crude oil will decrease the percentage losses due to evaporation by (0.016%) and decrease the change of °API by (0.9) during 96 hours storage time. Similarly using covering by surfactant (potassium oleate) or using polymer (polyurethane foam) decreases the percentage evaporation losses compare

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Publication Date
Mon Jan 13 2025
Journal Name
Al–bahith Al–a'alami
The attitudes of Iraqi youth towards volunteering work
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The aim of the research is to identify the attitudes of Iraqi youth
towards volunteering work by using the survey method and the scale
tool to identify what young volunteers can carry from the attitudes
towards volunteering work because the phenomenon of volunteer
work is of great importance in society. The scale was applied to
(525) volunteers among Iraqi youth. The research reached a set
of results, the most prominent of which is the existence of positive
trends among young people towards volunteering work, meaning
that Iraqi youth volunteers have awareness of the concept of
volunteering correctly. As for their goals of volunteering, they are
humanitarian and social goals for the advancement of society, an

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Publication Date
Sun Oct 01 2017
Journal Name
Al–bahith Al–a'alami
Issues of Media Trials in Iraqi after 2003
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The Supreme Judicial Council decided on July 3, 2003, to set up a court to deal with the issues of publication and media. This court tries to solve the problems of media and publishing in both its civil and penal aspects. The decision of establishing the court represents a new and important step to be taken by the Iraqi Judicial Council for the tremendous development witnessed by media sector in general and press in particular especially after 2003.
This study includes two main axes: the first one deals with the most important crimes of publication in the Iraqi legislations such as the crimes of defamation, libel, insult, indecency, and incitement; the second deals with an analytical survey of the completed cases i.e. the issues tha

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Publication Date
Wed Jun 29 2022
Journal Name
College Of Islamic Sciences
The Scientific Efforts of Ahmed Mustafa Al-Maraghi
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This conducted research,  (The Scientific Efforts of Ahmed Mustafa Al-Maraghi) deals with Al-Maraghi's life, birth, upbringing, characteristics, title, family and religion secter, as well as his general biography. And his relationship with scholars, his learning and teaching, and the introduction of the Muhammed Abdo School and the College of Dar Al Uloom, and finally the discussion  of his scientific, social and political poin of view, as an interpreter of twentieths century, was  appointed as the president of Al-Azhar and Ifta during the days of the royal era, and he studied at the College of Dar Al-Uloom

 

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