Preferred Language
Articles
/
ijl-51
Design High Efficient Reflectivity of Distributed Bragg Reflectors
...Show More Authors

Bragg Reflectors consist of periodic dielectric layers having an optical path length of quarter wavelength for each layer giving them important properties and makes them suitable for optoelectronics applications. The reflectivity can be increased by increasing the number of layers of the mirror to get the required value. For example for an 8 layers Bragg mirror (two layers for each dielectric pair), the contrast of the refractive index has to be equal to 0.275 for reaching reflectivity > 99%. Doubling the number of layers results in a reflectivity of 99.99%. The high reflectivity is purely caused by multiple-interference effects. It can be analyzed by using different matrix methods such as the transfer matrix method (TMM) which is the simplest method to study the characteristic of devices with different alternating layers.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Sep 15 2020
Journal Name
Al-academy
Formal Function of Guiding Sign in the design of Interior Spaces of Airports: أسـامـة غانـم نـوري -أحمـد ناجــي علــي
...Show More Authors

  The research addressed the formal functions resulting from the use of various guiding signs in the design of the interior spaces of airports in various pragmatic, expressive and psychological aspects. The aim is to identify the functions the guiding signs perform in facilitating and organizing the travelers' movement and satisfying the needs of the visitors and users of the unfamiliar places which they intend to visit, the nature of the services offered by these signs as one of the important parts within their general design. The research also identified the concept and types of signs as a means of visual communication and how to employ them in the design of the airports public spaces, and what are the criteria of their use and fu

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The effect of teaching design in accordance with cluster thinking strategies on First-grade-intermediate students’ achievement in science
...Show More Authors

The current study aims to develop a teaching design in accordance with cluster thinking strategies and explore the effect of this teaching design on students’ achievement in science. To this end, the null hypothesis was adopted: there is no statistically significant difference at the level of (0, 05) between experimental group who adopted the teaching design in learning science and control group who follow the traditional method in learning the same subject. To test the null hypothesis, total of (74) students from Al-Alaama Hussain Mahfooth intermediate school were selected intentionally for the academic year 2016-2017. The sample divided into two equal groups when all the variables (age, prior achievement of science,

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 15 2019
Journal Name
Al-academy
Virtual Reality Technology and its Uses in Industrial Product Design: فلاح حسن هادي -صلاح نوري محمود
...Show More Authors

The research (Virtual Reality Technology and its Uses in Industrial Product Design) is interested in the virtual reality technology used in the industrial product design and consequently knowing the functions achieved in the industrial product according to the data of that technology which participates in activating the mental and imaginary image of the user which show the parameters of the technical transformation of that product. The terms used in the research have been defined to guide the reader. The second chapter, the theoretical framework consisted of three sections the first is concerned with technology in the industrial design. The second is concerned with the virtual environment and the virtual reality. The thirds chapter consi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Design and Comparative Study of a one and Two Stage Blumlein Circuit TEA Nitrogen Laser
...Show More Authors

Two Prototypes of Transversely Excited at atmospheric pressure (TEA) Nitrogen laser systems (One Stage Blumlein Circuit and Two Stage Blumlein Circuit) were fabricated and operated. High voltage power supply with variable operating voltage (0-20 kv) and operating current (1-3A) was built and tested successfully. The gas flow rate of 15 L/ min and 10 L/ min for OSBC and TSBC was used. The performance of the fabricated systems was studied extensively reaching to the optimum operating conditions. The obtained laser output energy for the first system has linear relationship with the applied voltage. The maximum output energy was about (1.14 mJ) with (10.40) ns pulse duration and the half-wave divergence angle was about (0.1455 m rad). In the

... Show More
View Publication Preview PDF
Publication Date
Sat Jul 22 2023
Journal Name
Journal Of Engineering
Replacement of Line Loads acting on slabs to equivalent uniformly Distributed Loads
...Show More Authors

This study aims to derive a general relation between line loads that acting on two-way slab system and the equivalent uniformly distributed loads. This relation will be so useful to structural designer that are used to working with a uniformly distributed load and enable them to use the traditional methods for analysis of two-way systems (e.g. Direct Design Method). Two types of slab systems, Slab System with Beams and Flat Slab Systems, have been considered in this study to include the effect of aspect ratio and type of slab on the proposed relation. Five aspect ratios, l2/l1 of 0.5, 0.75, 1.0, 1.5 and 2.0, have been considered for both types of two-way systems.
All necessary finite element analyses have been executed with SAFE Soft

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Structural Behavior of Reinforced Concrete Hollow Beams under Partial Uniformly Distributed Load
...Show More Authors

A Longitudinal opening is used to construct hollow core beam is a cast in site or precast or pre stressed concrete member with continuous voids provided to reduce weight, cost and, as a side benefit, to use for concealed electrical or mechanical runs. Primarily is used as floor beams or roof deck systems. This study investigate the behavior of six beams (solid or with opening) of dimension (length 1000 x height 180 x width120mm) simply support under partial uniformly distributed load, four of these beam contain long opening of varied section (40x40mm) or (80x40mm). The effect of vertical steel reinforcing, opening size and orientations are investigated to evaluate the response of beams. The experimental behavior based on load-deflection

... Show More
View Publication Preview PDF
Crossref (13)
Crossref
Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Genetic Algorithm Based PID Controller Design for a Precise Tracking of Two-Axis Piezoelectric Micropositioning Stage
...Show More Authors

 In this paper, an intelligent tracking control system of both single- and double-axis Piezoelectric Micropositioner stage is designed using Genetic Algorithms (GAs) method for the optimal Proportional-Integral-Derivative (PID) controller tuning parameters. The (GA)-based PID control design approach is a methodology to tune a (PID) controller in an optimal control sense with respect to specified objective function. By using the (GA)-based PID control approach, the high-performance trajectory tracking responses of the Piezoelectric Micropositioner stage can be obtained. The (GA) code was built and the simulation results were obtained using MATLAB environment. The Piezoelectric Micropositioner simulation model with th

... Show More
View Publication Preview PDF
Publication Date
Sat Jun 12 2021
Journal Name
2021 International Conference On Electrical, Communication, And Computer Engineering (icecce)
Efficient Private Cloud Resources Platform
...Show More Authors

View Publication
Scopus (2)
Crossref (2)
Scopus Crossref
Publication Date
Mon Nov 29 2021
Journal Name
Iraqi Journal Of Science
Efficient Plain Password Cryptanalysis Techniques
...Show More Authors

In this research work, some low complexity and efficient cryptanalysis approaches are proposed to decrypt password (encryption keys). Passwords are still one of the most common means of securing computer systems. Most organizations rely on password authentication systems, and therefore, it is very important for them to enforce their users to have strong passwords. They usually ignore the importance of usability of the password for the users. The more complex they are the more they frustrate users and they end up with some coping strategies such as adding “123” at the end of their passwords or repeating a word to make their passwords longer, which reduces the security of the password, and more importantly there is no scientific basis

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 15 2020
Journal Name
Al-academy
Formal Data of Bauhaus School and their Implications for Fabrics and Costumes Design: نور منصور خميس-وسن خليل ابراهيم
...Show More Authors

The current research discusses the topic of the formal data within the methodological framework through defining the research problem, limits and objectives and defining the most important terms mentioned in this research. The theoretical framework in the first section addressed (the concept of the Bauhaus school, the philosophy of the Bauhaus school and the logical bases of this school). The second section dealt with (the most important elements and structural bases of the Bauhaus school) which are considered the most important formal data of this school and their implications on the fabrics and costumes design. The research came up with the most important indicators resulting from the theoretical framework.
Chapter three defined the

... Show More
View Publication Preview PDF
Crossref