Preferred Language
Articles
/
OBdc4I4BVTCNdQwCYFl_
Absorption Coefficient of a Double-Layer Inhomogeneous Micro-perforated Panel Backed with Multiple Cavity Depths
...Show More Authors

Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared with the conventional double- and even triple-layer MPPs. The bandwidth can be increased to higher frequency by decreasing the cavity depth behind a sub-MPP with small hole diameter and a high perforation ratio, and to lower frequency by increasing the cavity depth behind a sub-MPP with large hole diameter and a small perforation ratio. The experimental data, measured by impedance tube, are in good agreement with the predicted results.

Scopus Clarivate Crossref
View Publication
Publication Date
Sun Jul 27 2025
Journal Name
Journal Of Baghdad College Of Dentistry
An Evaluation of Corrosion Pits in Esthetic Coated Stainless Steel Orthodontic Archwires in Dry and Wet Environment at Different Intervals (An In Vitro Study)
...Show More Authors

Background: The demand for esthetic orthodontic appliances is increasing; so the esthetic orthodontic archwires were introduced. Among them, Teflon and Epoxy coated stainless steel archwires. The amount of force available from the archwire depends on the structural properties and susceptibility to corrosion. All metallic alloys are changed during immersion in artificial saliva, chlorhexidine mouthwash andtoothpaste, but their behaviors differ from one type to another. They corrode at different rates, which lead to decrease the amount of force applied to the teeth. This in vitro study was designed to evaluate the corrosion pits in stainless steel archwires coated with Teflon and with Epoxy in dry and after immersion in artificial saliva, chl

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Fri Jan 24 2020
Journal Name
International Journal Of Pharmaceutical Research
Preparation, spectral characterization and biological activity of somenewbimetalic complexes derived from{ 2,2`((5-methyl-1,3-phenylene)-bis- (oxy))-bis-N`(E`)-2- hydroxybenzylideneacetohydrazide}ligand
...Show More Authors

In this work, the preparation of new multidentate Schiff-base lig and and its metal complexes are described. The formation of the lig and{ 2,2`((5-methyl-1,3-phenylene)-bis-(oxy))-bis-N`(E`)-2- hydroxybenzylideneacetohydrazide}[H2L] was prepared from the reaction {2,2-((5-methyl-1,3-phenylene)-bis-(oxy))- di-(acetohydrazide)}[M]precursor and salicylaldehyde in a 1:2 mole ratio, respectively. The reaction of the lig and [H2L] with (Cr+3 , Mn+2 and Fe+2 )metal ions in a 1:2 (L:M) mole ratio. Ligand and complexes were characterised via spectroscopic analyses; [FT-IR, UV-Vis spectroscopy,(C.H.N) microanalysis, chloride content, thermal analysis(TG), electrospray mass, magnetic susceptibility and conductivity measurements. The characterisation d

... Show More
View Publication
Publication Date
Sun Jul 27 2025
Journal Name
Journal Of Physical Education
The Effect of Breathing Exercises on Relation and Self – Talk on Developing Ambition Level According to VTS – Sport and Achievement in Long Distance Runners
...Show More Authors

View Publication
Publication Date
Sat Sep 30 2023
Journal Name
Iraqi Geological Journal
Geology, Pb and S Isotope Geochemistry, and Genesis of the Na Bop-Pu Sap Lead-Zinc Deposit in the Cho Don area, Northeastern Vietnam
...Show More Authors

The Na Bop-Pu Sap Pb-Zn ore bodies represent a typical vein-type lead-zinc deposit situated in the Cho Don area and are currently being extracted for their lead and zinc resources. This deposit is characterized by its significant scale and quality and is considered one of the prominent lead-zinc deposits in the Cho Don area. Despite its significance, this deposit has not received adequate attention, resulting in limited knowledge of its geology, mineralization, and deposit genesis model. To address this knowledge gap, our study utilized several methodologies, including field surveying, ore mineral analysis under a microscope, and S and Pb isotopic geochemistry. By employing these approaches, we were able to obtain specific insights

... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Thu Oct 26 2023
Journal Name
Malaysian Journal Of Science
HEMICAL ELUCIDATION AND BIOLOGICAL SCREENING STUDY OF NEW LIGAND DERIVED FROM 5, 6-O-ISO PROPYLIDENE-L-ASCORBIC ACID AND ITS METAL (II) COMPLEXES
...Show More Authors

الوصف A simple chemistry method approach was used to synthesise new ligand derivate from L-ascorbic acid and its complexes. All of them were water-soluble and are used quite extensively in the medical and pharmaceutical fields. This study synthesised the new ligand derivative from L-ascorbic acid-base using the following steps: A 5, 6-O-isopropylidene-L-ascorbic acid was prepared by reacting dry acetone with L-ascorbic acid followed by reacting it with trichloroacetic acid to yield [chloro (carboxylic) methylidene]-5, 6-O-isopropylidene-L-ascorbic acid in the second stage. In the third stage, the derivative was reacted with (methyl (6-methyl-2-pyridylmethyl) amine to create a new ligand (ONMILA). This novel ligand was identified using

... Show More
Publication Date
Mon Mar 13 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Localization of Maxillary Impacted Canine Using Cone Beam Computed Tomography for Assessmentof Angulation, Distance From Occlusal Plane, Alveolar Width and Proximity to Adjacent Teeth
...Show More Authors

ABSTRACT Backgrounds: Maxillary canine impaction is complicated and time consuming to treat, for being highly diverse in inclination and location; it may be a companied by root resorption of the neighboring teeth. CBCT has been used for its' diagnostic reliability in localization of impacted canine and revealing its' serious local complications. Objectives: Localization of maxillary impacted canine using cone beam computed tomography for assessment of angulation, distance from occlusal plane, alveolar width and proximity to adjacent teeth. Subjects and Methods: The study sample was 33 subjects 16 females and 17 males attended to Al-Wasitti general hospital in Baghdad city-Oral and maxillofacial radiology department for CBCT scan investigati

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Dec 31 2021
Journal Name
Journal Of Communicable Diseases
The Relation between RT-PCR and Chest CT Scan Sensitivity as Tools in the Diagnosis of COVID-19 Patients in Al-Najaf Province, Iraq
...Show More Authors

The typical test for diagnosis of severe acute respiratory syndrome coronavirus 2 is a reverse transcription-polymerase chain reaction (RT-PCR) technique, but the chest CT scan might play a complementary role at the first detection of Coronavirus Disease 2019 (COVID-19) pneumonia. Objectives: To determine the sensitivity of CT scan on patients with COVID-19 in Al-Najaf, Iraq, and to compare the accuracy of CT scan with that of RT-PCR technique. Material and Method: This is a prospective study. The patients suspicious of having COVID-19 infection and respiratory symptoms were registered. All patients were diagnosed by RT-PCR and chest CT. Diagnostic performance of CT was intended using RT-PCR as the reference sta

... Show More
View Publication Preview PDF
Crossref (1)
Scopus Crossref
Publication Date
Sun Mar 06 2011
Journal Name
Baghdad Science Journal
The Calculation of the partical distribution function g(r12,r1) for Carbon Ion cases (C+2,C+3,C+4) in the position space
...Show More Authors

The aim of this work is study the partical distribution function g(r12,r1) for Carbon ion cases (C+2,C+3,C+4) in the position space using Hartree-Fock's Wave function, and the partitioning technique for each shell which is represented by Carbon Ions [C+2 (1s22s2)], [C+3 (1s22s)] and [C+4 (1s2)]. A comparision has been made among the three Carbon ions for each shell. A computer programs (MATHCAD ver. 2001i) has been used texcute the results.

View Publication Preview PDF
Crossref
Publication Date
Tue Feb 26 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Role of Managerial Accounting Information System in Improving the Value Chain and its Impaction Evaluation Performance: دراسة حالة في الشركة العامة لصناعة الزيوت النباتية
...Show More Authors

The performance measures and traditional methods used in management accounting is no longer able to provide convenient to evaluate the performance of economic units in the modern manufacturing environment information، and so this information is more important and feasibility must be Mistohat of all the company's activities and functions، and it is a problem Find the inadequacy of information management accounting that contribute to meet the needs of the upper levels of management to cope with the problems resulting from the increased size and complexity of the business، and lack of management accounting information and methods used in the performance evaluation، which reflected negatively on the value chain activities and then on the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
The effect of aqueous extracts and isolation proteinous compound from clove buds on serumglucose, triglyceride , glutathione and malnodialdehyde levels in alloxan induced diabetic mice
...Show More Authors

This study was included preparing acold aqueous extract of clove buds The study also comprised the isolation and studying the proteinous compound,which was seperated using gel filtration technique and determined approximately molecular weight of this isolated compound(6799) dalton . The aim of the study demonstrate effects of the crude aqueous, non proteinous extract, proteinous precipitate and proteinous compound on serum glucose, total cholesterol, triglyceride and high density lipoprotein-cholesterol levels, also glutathione and malondialdehyde levels in liver and kidney tissues in diabetic mice-induced alloxan.Extracts were administerated interaperitioneally. The results were indicated that the crude aqueous, non proteinous extr

... Show More
View Publication Preview PDF
Crossref