Preferred Language
Articles
/
joe-673
Comparative Analysis of Various Multicarrier Modulation Techniques for Different Multilevel Converters
...Show More Authors

The applications of Multilevel Converter (MLC) are increased because of the huge demand for clean power; especially these types of converters are compatible with the renewable energy sources. In addition, these new types of converters have the capability of high voltage and high power operation. A Nine-level converter in three modes of implementation; Diode Clamped-MLC (DC-MLC), Capacitor Clamped-MLC (CC-MLC), and the Modular Structured-MLC (MS-MLC) are analyzed and simulated in this paper. Various types of Multicarrier Modulation Techniques (MMTs) (Level shifted (LS), and Phase shifted (PS)) are used for operating the proposed Nine level - MLCs. Matlab/Simulink environment is used for the simulation, extracting, and analysis the results. Finally, a comparison is made between the results for all topologies that are implemented regarding to the criteria of the output voltage waveforms harmonic distortion factor, No. of the necessitated power components, and the complexity of each circuit. Based on simulation results, the MS-MLC is finer as compared to the other types of MLCs. It also observed that the MLCs (with three types) using Phase Opposition Disposition (POD) technique is performed better in terms of getting greater fundamental output voltage and lower THD% as compared to the other techniques.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Study of NOx Emissions of S.I. Engine Fueled with Different Kinds of Hydrocarbon Fuels and Hydrogen
...Show More Authors

 

      Liquefied petroleum gas (LPG), Natural gas (NG) and hydrogen were used to operate spark ignition internal combustion engine Ricardo E6, to compare NOx emissions emitted from the engine, with that emitted from engine fueled with gasoline as a fuel.

      The study was done when engine operated at HUCR for gasoline, compared with its operation at HUCR for each fuel. Compression ratio, equivalence ratio and spark timing were studied at constant speed 25rps.

The results appeared that NOx concentrations will be at maximum value in the lean side near the stoichiometric ratio, and reduced with moving away from this ratio for mixture at both s

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
Assessment of Enamel Surface after Debonding of Different Types of Esthetic Brackets (An In Vitro Study)
...Show More Authors

Background: Debonding orthodontic brackets and removal of residual bonding material from the enamel surface include critical steps that may cause enamel damage. The aim of the present study was to evaluate and compare the site of bond failure and enamel surface damage after debonding of three types of esthetic brackets (composite, ceramic, sapphire) bonded with light cure composite and resin-modified glass ionomer adhesive. Materials and methods: Seventy two maxillary premolars teeth were divided into three groups each group consisted of 24 teeth according to the type of brackets. Each group was subdivided into two subgroups (12 teeth for each) according to the bonding material that was used. After 7 days of bonding procedure, the brackets

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Fri Nov 01 2019
Journal Name
Journal Of Engineering
Analysis of Shell and Double Concentric Tube Heat Exchanger Using CFD Application
...Show More Authors

This study focuses on CFD analysis in the field of the shell and double concentric tube heat exchanger. A commercial CFD package was used to resolve the flow and temperature fields inside the shell and tubes of the heat exchanger used. Simulations by CFD are performed for the single shell and double concentric tube.

This heat exchanger included 16 tubes and 20 baffles. The shell had a length of 1.18 m and its diameter was 220 mm. Solid Works 2014, ANSYS 15.0 software was used to analyze the fields of flow and temperature inside the shell and the tubes. The RNG k-ε model was used and it provided good results. Coarse and fine meshes were investigated, showing that aspect ratio has no significant effect. 14 million

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Wed Dec 30 2020
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Detection and isolation of flavonoid and aromatic acid from Cynara scolymus different parts cultivated in iraq
...Show More Authors

The target of this study was to study the natural phytochemical components of the head (capsule) of Cynara scolymus cultivated in Iraq. The head (capsule) of plant was extracted by maceration in70% ethanol for 72 hours, and fractioned by hexane, chloroform and ethyl acetate. Preliminary qualitative phytochemical screening was performed on the ethyl acetate fraction for capsule was revealed the presence of flavonoid and aromatic acids. These were examined by (high -performance liquid chromatography) (HPLC diodarray), (high- performance thin-layer chromatography)(HPTLC).

Flavonoids were isolated by preparative layer chromatography and aromatic acid was isolated by preparative high-

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Crossref
Publication Date
Sat Jun 30 2018
Journal Name
Journal Inspector General
Some Forms of Fault Committed by Police Officers – A Comparative Study of Civil Liability under American and Iraqi Law
...Show More Authors

Police play an important role in any society. Where they maintain public order by stopping and deterring crime and bringing criminals to justice. In order to achieve these objectives, they have certain means of law (search, arrest, use of force that may be lethal in some cases). However, such means may be misused in a way that harms members of society such as (Exceeding the Scope of a search warrant, violation of privacy of individuals, False Imprisonment, Excessive use of force, Sudden Deaths in custody, Sexual Assault and Harassment, Failure to respond for Domestic violence calls), which raises the civil liability of police officers and their agencies for such damage. Police officers may even abuse their characteristics even outside offic

... Show More
View Publication
Publication Date
Sun Jun 07 2015
Journal Name
Baghdad Science Journal
A comparative study to determine the nature of the eye lens protein in the two types of birds Iraqi
...Show More Authors

The study showed significant differences between the average weight lens and the average amount protein in the lens between that Kestrel Falco tinnunculus L. and the Collared Dove Streptopelia decaocto F. , also the study electrical migration of lens proteins having one bundle of crystalline –? in Kestrel compared with three bundles in Collared Dove, two bundles of crystalline – ? in both , and crystalline – ? appeared as one bundle in both birds.

View Publication Preview PDF
Crossref
Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Evaluation of 532 nm Q-Switched Nd:YAG Laser and Acid Etching of Class V Composite Restoration: Comparative Histological Study
...Show More Authors

Laser etching may be an alternative to acid etching of enamel and dentin. Several characteristics of irradiated dental hard tissues have been considered advantageous, microscopically rough surfaces without demineralization, open dentinal tubules without smear layer production and dentin surface sterilization. The aim of this study is to determine and compare histology the microleakage in class V cavity restored with a light cured composite after conditioning the samples(tooth surface) with 1-acid etching, 2-Q-switched Nd:YAG Laser etching and finally 3- acid and laser etching. Materials and methods: Twenty four non carious human extracted teeth were used in this study. The samples were equally grouped into four groups of six teeth each.

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 03 2024
Journal Name
Functional Foods In Health And Disease
A comparative study of the effect of extracts extracted from Ocimum basilicum leaves using organic extract and essential oil
...Show More Authors

Background: Medicinal plants that possess antimicrobial and antioxidant properties have garnered significant attention for their role in maintaining food quality, improving safety, and impeding spoilage. They also can aid in controlling food contamination risks and augmenting the nutritional value of foods. Objective: The study aimed to obtain botanical extracts possessing antimicrobial capabilities and use them to inhibit the growth of molds and yeasts. Additionally, these extracts are aimed at prolonging product shelf life by harnessing their antioxidant attributes. Methods: Several microorganisms, including E. coli and Pseudomonas, were subjected to testing. Ethanolic alcohol, chloroform, and essential oil extracts were prepared;

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Wed Jul 01 2015
Journal Name
Journal Of Engineering
A comparative Isothermal and Kinetic Study of the Adsorption of Lead (II) from Solution by Activated Carbon and Bentonite
...Show More Authors

This work is aiming to study and compare the removal of lead (II) from simulated wastewater by activated carbon and bentonite as adsorbents with particle size of 0.32-0.5 mm. A mathematical model was applied to describe the mass transfer kinetic.

The batch experiments were carried out to determine the adsorption isotherm constants for each adsorbent, and five isotherm models were tested to choose the best fit model for the experimental data. The pore, surface diffusion coefficients and mass transfer coefficient were found by fitting the experimental data to a theoretical model. Partial differential equations were used to describe the adsorption in the bulk and solid phases. These equations were simplified and the

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
The A Comparative Study of the Adsorption of Crystal Violet Dye from Aqueous Solution on Rice Husk and Charcoal
...Show More Authors

            In this work, the adsorption of crystal violet dye from aqueous solution on charcoal and rice husk has been investigated, where the impact of variable factors (contact time; the dosage of adsorbent, pH, temperature, and ionic strength) have been studied. It has been found that charcoal and rice husk have an appropriate adsorption limit with regards to the expulsion of crystal violet dye from fluid arrangements. The harmony adsorption is for all intents and purposes accomplished in 45 min for charcoal and 60 min for rice husk. The amount of crystal violet dye adsorbed (0.4 g of charcoal and 0.5 g of rice husk) increased with an increasing pH and the value of 11 is the best

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (2)
Scopus Clarivate Crossref