Preferred Language
Articles
/
alkej-588
Design and Simulation of GaussianFSK Transmitter in UHF Band Using Direct Modulation of ΣΔ Modulator Fractional-N Synthesizer
...Show More Authors

This research involves design and simulation of GaussianFSK transmitter in UHF band using direct modulation of ΣΔ  fractional-N synthesizer with the following specifications:

Frequency range (869.9– 900.4) MHz, data rate 150kbps, channel spacing (500 kHz), Switching time 1 µs, & phase noise @10 kHz = -85dBc.

New circuit techniques have been sought to allow increased integration of radio transmitters and receivers, along with new radio architectures that take advantage of such techniques. Characteristics such as low power operation, small size, and low cost have become the dominant design criteria by which these systems are judged.

A direct modulation by ΣΔ  fractional-N synthesizer is proposed in this research, because this approach provides the required characteristics such as low power. The Σ∆ modulator placed on digital phase-locked loop to control the fractional value of the frequency division ratio thereby eliminating spurious and allowing good phase noise performance. The modulation type of Gaussian FSK is used to obtain high spectral efficiency of modulated waveform.

The applications of this transmitter in low cost wireless data transfer, security systems, RF remote controls and wireless metering.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jan 14 2018
Journal Name
Journal Of Engineering
Direct Shear Behavior of Fiber Reinforced Concrete Elements
...Show More Authors

Improving the accuracy of load-deformation behavior, failure mode, and ultimate load capacity for reinforced concrete members subjected to in-plane loadings such as corbels, wall to foundation connections and panels need shear strength behavior to be included. Shear design in reinforced concrete structures depends on crack width, crack slippage and roughness of the surface of cracks.

This paper illustrates results of an experimental investigation conducted to investigate the direct shear strength of fiber normal strength concrete (NSC) and reactive powder concrete (RPC). The tests were performed along a pre-selected shear plane in concrete members named push-off specimens. The effectiveness of concrete compressiv

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Engineering
ELECTROCHEMICAL DECOLORIZATION OF DIRECT BLACK TEXTILE DYE WASTEWATER
...Show More Authors

Electrochemical decolorization of direct black textile dye was studied in the presence of sodiumhydroxide (NaCl). Electrochemical cell occupy about 1 liter of working electrolyte supplied with graphiteelectrodes for both anode and cathode was constructed for this purpose. Decolorization percent, treatment time, power consumption, and pH were studied as a function of the applied voltage and salt concentration. Results show that decolorization increase with increasing salt concentration and applied voltage. Best decolorization of 86% can be achieved after 17 min at 7 volt and 5 g/l salt concentration. Further decolorization can be achieved but this will be accompanied with a sharp increase in power consumption. No significant decrease

... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
Simulation of Heat Storage and Heat Regeneration in Phase Change Material
...Show More Authors

The present study explores numerically the energy storage and energy regeneration during Melting and Solidification processes in Phase Change Materials (PCM) used in Latent Heat Thermal Energy Storage (LHTES) systems. Transient two-dimensional (2-D) conduction heat transfer equations with phase change have been solved utilizing the Explicit Finite Difference Method (FDM) and Grid Generation technique. A Fortran computer program was built to solve the problem. The study included four different Paraffin's. The effects of container geometrical shape, which included cylindrical and square sections of the same volume and heat transfer area, the container volume or mass of PCM, variation of mass flow rate of heat transfer fluid (HTF), and temp

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Sun Jan 01 2017
Ultra low power and highly linearized LNA for V-band RF applications in 180 nm CMOS technology
...Show More Authors

Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Mon Jun 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Use of lower squares and restricted boxes In the estimation of the first-order self-regression parameter AR (1) (simulation study)
...Show More Authors

Use of lower squares and restricted boxes
In the estimation of the first-order self-regression parameter
AR (1) (simulation study)

View Publication Preview PDF
Crossref
Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
High Order Sliding Mode Observer-Based Output Feedback Controller Design For Electro-Hydraulic System
...Show More Authors

A perturbed linear system with property of strong observability ensures that there is a sliding mode observer to estimate the unknown form inputs together with states estimation. In the case of the electro-hydraulic system with piston position measured output, the above property is not met. In this paper, the output and its derivatives estimation were used to build a dynamic structure that satisfy the condition of strongly observable. A high order sliding mode observer (HOSMO) was used to estimate both the resulting unknown perturbation term and the output derivatives. Thereafter with one signal from the whole system (piton position), the piston position make tracking to desire one with a simple linear output feedback controller after ca

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Engineering
Identificatio n Of Key Factors Affecting Waste Management In Life Cycle Of The Construction Project By Using Delphi Technique
...Show More Authors

The problem of generated waste as a result of the implementation of construction projects, has  been aggravated recently because of construction activity experienced by the world, especially Iraq, which is going through a period of reconstruction, where construction waste represents (20-40%) of the total generated waste and has a negative effect on the environment and economic side of the project. In addition, the rate of consumpted  amounts of natural resources are estimated to be about 40% in the construction industry, so it became necessary to reduce waste and to be manage well. This study aims to identify the key factors affecting waste management through the various phases of the project, and this is accom

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 30 2021
Journal Name
Iraqi Geological Journal
The Effect of Weighting Materials on the Rheological Properties of Iraqi and Commercial Bentonite in Direct Emulsion
...Show More Authors

Numerous drilling additives and materials are used continuously because they are necessary to support and give the required properties of the drilling fluid so that to ensure the stability of the borehole. This paper aspires to evaluate the rheological properties of bentonite (montmorillonite) Trefawey as an alternative to using commercial bentonite. Monitoring and evaluating of the rheological and filtration properties were prepared. This exertion aims to focus on the effect of hematite, and barite on the rheological properties of the three aforementioned bentonite types. An improvement in the rheological properties of bentonite (montmorillonite). Trefawey was observed after adding the previous heavy materials. Hematite has by some

... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Tue Mar 10 2020
Journal Name
Journal Of Inverse And Ill-posed Problems
Direct and inverse source problems for degenerate parabolic equations
...Show More Authors
Abstract<p>Degenerate parabolic partial differential equations (PDEs) with vanishing or unbounded leading coefficient make the PDE non-uniformly parabolic, and new theories need to be developed in the context of practical applications of such rather unstudied mathematical models arising in porous media, population dynamics, financial mathematics, etc. With this new challenge in mind, this paper considers investigating newly formulated direct and inverse problems associated with non-uniform parabolic PDEs where the leading space- and time-dependent coefficient is allowed to vanish on a non-empty, but zero measure, kernel set. In the context of inverse analysis, we consider the linear but ill-pose</p> ... Show More
View Publication
Scopus (27)
Crossref (19)
Scopus Clarivate Crossref
Publication Date
Thu Aug 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Aggregate production planning using linear programming with practical application
...Show More Authors

Abstract :

The study aims at building a mathematical model for the aggregate production planning for Baghdad soft drinks company. The study is based on a set of aggregate planning strategies (Control of working hours, storage level control strategy) for the purpose of exploiting the resources and productive capacities available in an optimal manner and minimizing production costs by using (Matlab) program. The most important finding of the research is the importance of exploiting during the available time of production capacity. In the months when the demand is less than the production capacity available for investment. In the subsequent months when the demand exceeds the available energy and to minimize the use of overti

... Show More
View Publication Preview PDF
Crossref