Preferred Language
Articles
/
alkej-29
Design & Implementation of High Switching & Low Phase Noise Frequency Synthesizer
...Show More Authors

This research  describes the design & implementation of frequency synthesizer using single loop Phase lock loop with the following specifications: Frequency range (1.5 – 2.75) GHz,Step size (1 MHz), Switching time 36.4 µs, & phase noise @10 kHz = -92dBc & spurious -100 dBc

  The development in I.C. technology provide the simplicity in the design of frequency synthesizer because it implements the phase frequency detector(PFD) , prescalar &  reference divider in single chip. Therefore our system consists of  a single chip contains (low phase noise PFD, charge pump, prescalar  & reference divider), voltage controlled oscillator , loop filter & reference oscillator. The single chip is used to provide the following properties :

  • Low power consumption.
  • Small size, light weight.
  • Flexibility in selecting crystal oscillator frequencies to fit into the system frequency planning.
  • High reliability.

The application of this synthesizer  in frequency hopping systems, satellite communications & radar because it has high switching speed  ,low phase noise & low spurious level.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Jul 09 2022
Journal Name
Optik
The role of Ag NPs in PVA electrospun NFs for ultra-high sensitivity photodetector
...Show More Authors

This work aimed to produce PVA and PVA/Ag nanofibers ultra-high sensitivity photodetector by electrospinning. The electrospinning process was used to successfully prepare PVA nanofibers and a PVA-Ag nanofiber composite. FE-SEM, XRD, UV, I-V characterizations are used to study the morphological, structural, optical, and electrical properties of the material. In contrast, the PVA-Ag nanofiber composite film displayed a cubic structure with favored orientation (200) that indicated the presence of Ag NPs in the PVA-Ag nanofibers film. While the optical energy gap for PVA was 3.96 eV, it was only 2.14 eV for PVA-Ag nanofibers composite film, making this composite sensitive to visible light, particularly green light at 550 nm with a 65% photosens

... Show More
Scopus (6)
Scopus
Publication Date
Sun Jan 01 2023
Journal Name
8th Engineering And 2nd International Conference For College Of Engineering – University Of Baghdad: Coec8-2021 Proceedings
Serviceability performance of high-strength concrete flexural members with internally unbonded post-tensioning strands
...Show More Authors

View Publication
Crossref
Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Solution of Nonlinear High Order Multi-Point Boundary Value Problems By Semi-Analytic Technique
...Show More Authors

In this paper, we present new algorithm for the solution of the nonlinear high order multi-point boundary value problem with suitable multi boundary conditions. The algorithm is based on the semi-analytic technique and the solutions are calculated in the form of a rapid convergent series. It is observed that the method gives more realistic series solution that converges very rapidly in physical problems. Illustrative examples are provided to demonstrate the efficiency and simplicity of the proposed method in solving this type of multi- point boundary value problems.

View Publication Preview PDF
Crossref
Publication Date
Thu Feb 01 2018
Journal Name
Association Of Arab Universities Journal Of Engineering Sciences
Performance of composite unprotected steel Beam-deck floor exposed to high temperature (fire flame)
...Show More Authors

An experimental program was conducted to determine the residual of composite Steel Beams-Reinforced Concrete (SB-RC) deck floors fabricated from a rolled steel beam topped with a reinforced concrete slab, exposed to high temperatures (fire flame) of 300, 500, and 700ºC for 1 hour, and then allowed to cool down by leaving them in the lab condition to return to the ambient temperature. The burning results showed that, by exposing them to a fire flame of up to 300ºC, no serious permanent deflection occurred. It was also noticed that the specimen recovered 93% of 19.2 mm of the deflection caused by burning. The recovered deflection of burned composite SB-RC deck floor at 500ºC was 40% of 77.9 mm of the deflection caused by burning with a res

... Show More
View Publication Preview PDF
Publication Date
Thu Jul 21 2022
Journal Name
Al-academy
المضامين الفكرية في تصميم الطوابع العراقية
...Show More Authors

تعد الطوابع احدى وسائل الاتصال المهمة في المجتمع لما تتميز به من مستوى في القيمة الفنية والفكرية، فضلاً عن كونها وسيلة من وسائل الخطاب الاعلامي وذلك لتعدد وظائفها التي من ابرزها:التوثيق لمرحلة معينة وحدث ما.التداولية الرسمية للمراسلات المحلية والعالمية.الاعلانية كونها تعطي انطباعاً عن مراحل التطور والتقدم الاجتماعي والحضاري والسياسي للمجتمع.الدعائية لما تتضمنه من مفاهيم وأفكار وتوجهات سياسية واقتصادية

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 01 2004
Journal Name
Al-academy
تصميم حرف طباعي وفق النسبة الذهبي
...Show More Authors

تصميم حرف طباعي وفق النسبة الذهبي

View Publication Preview PDF
Publication Date
Mon Mar 25 2019
Journal Name
Al-academy
Effectiveness of Interpretation in Graphic Design: سحر علي سرحان
...Show More Authors

The interpretation is one of the means used to by the designer to construct his perceptions of the world in which he lives, either to better understand or rediscover or reproduce the new thing and the creative thing which is characterized by novelty and originality. The design innovations in the political posters, achieved by the designer, result from his perceptions for the response towards a certain subject through what he has of practical experience to interpret his ideas and his desire to achieve harmony with the reality and compatibility with his aims in visible visual effects that will be established in the recipient's memory and stimulate his senses in the realization of the content of the media message. The political poster has a

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 15 2023
Journal Name
Al-academy
The influence of the Bauhaus in contemporary graphic design
...Show More Authors

This research aims to study and reveal the influence of Bauhaus principles in contemporary graphic design. The researcher determined the objective/spatial/temporal limit: Study of the Bauhaus influence in the design of the graphic poster in Germany in 2020. The theoretical framework in the first section dealt with (the emergence and factors of the emergence of the Bauhaus school and its characteristics), while the second topic dealt with (the intellectual, functional and aesthetic data of the Bauhaus School), after which the indicators that resulted from the theoretical framework were produced.

He mentioned four previous studies, one of them was discussed in detail. In the third chapter he defined the methodology, society, and sam

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Nov 01 2011
Journal Name
International Journal Of Mechanical And Materials Engineering
Simulation and design optimization of magneto rheological control valve
...Show More Authors

Magneto-rheological (MR) Valve is one of the devices generally used to control the speed of Hydraulic actuator using MR fluid. The performance of valve depends on the magnetic circuit design. Present study deals with a new design of MR valve. The finite element analysis is carried out on this valve to optimize its design. The design of the magnetic circuit is accomplished by magnetic finite element software such as Finite Element Method Magnetic (FEMM). The Model dimensions of MR valve, material properties and the circuit properties of valve coil are taken into account. The results of analysis are presented in terms of magnetic strength and magnetic flux density. The valve can be operated with variable flow rate by varying the current. It i

... Show More
View Publication Preview PDF
Scopus (2)
Scopus
Publication Date
Thu Jan 08 2026
Journal Name
Basic Education College Magazine For Educational And Humanities Sciences
Developing the design structure of Iraqi children magazine covers
...Show More Authors

View Publication