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
Tue Sep 29 2026
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of smear layer on push-out bond strength to dentin of Bioceramic sealer (In vitro study)
...Show More Authors

Background: Sealers should demonstrate adhesive properties to dentin, decreasing the chance of endodontic treatment failure. Increased adhesive properties to dentin may lead to greater strength of the restored tooth, which may provide greater resistance to tooth fracture and clinical longevity of an endodontically treated tooth. The aim of this study was to evaluate the shear bond strength of Bioceramic iRoot SP sealer, AH plus sealer and Apexit plus sealer in absence or presence of smear layer using push out bond strength test. Materials and Methods: Sixty straight single roots of the mandibular premolars were selected for this study. All canals were instrumented using ProTaper rotary instruments to achieve tapered canal walls, instrumenta

... Show More
View Publication Preview PDF
Publication Date
Thu Jul 01 2010
Journal Name
International Journal Of Advancements In Computing Technology
Implementation of digital chaotic signal generator based on reconfigurable LFSRs for multiple access communications
...Show More Authors

This paper describes the digital chaotic signal with ship map design. The robust digital implementation eliminates the variation tolerance and electronics noise problems common in analog chaotic circuits. Generation of good non-repeatable and nonpredictable random sequences is of increasing importance in security applications. The use of 1-D chaotic signal to mask useful information and to mask it unrecognizable by the receiver is a field of research in full expansion. The piece-wise 1-D map such as ship map is used for this paper. The main advantages of chaos are the increased security of the transmission and ease of generation of a great number of distinct sequences. As consequence, the number of users in the systems can be increased. Rec

... Show More
Scopus (3)
Scopus
Publication Date
Tue Jan 02 2018
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Multiple choice questions and essay questions in assessment of success rate in medical physiology
...Show More Authors

Background: Assessment is an important part of the learning cascade in education. Students realize it as an influential motivator to direct and guide their learning. The method of assessment determines the way the students reach high levels of learning. It has been documented that one of factor affecting students’ choice of learning approach is the way how assessment is being performed. Many methods of assessment namely multiple choice questions, essay questions and others are mainly used to assess basic science knowledge in undergraduate education. Objectives: The aim of this study is to compare multiple choice questions (MCQ) and essay questions (EQ) (record the success and failure rate of multiple choice questions (MCQ) and essay quest

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Nov 01 2020
Journal Name
2020 8th Ieee Ras/embs International Conference For Biomedical Robotics And Biomechatronics (biorob)
Estimating Wrist Joint Torque Using Regression Ensemble of Bagged Trees under Multiple Wrist Postures
...Show More Authors

View Publication
Scopus (3)
Crossref (4)
Scopus Crossref
Publication Date
Wed Jan 01 2025
Journal Name
Iraqi National Journal Of Earth Science (injes)
The Effect of Satellite Image Fusion on the Classification Process by Using Multiple Sensors
...Show More Authors

View Publication
Crossref (1)
Scopus Crossref
Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
Derivative Zero - Crossing Spectrophotometry Of Binary Mixtures Of Acetyl Acetonates Of Micro – Amounts Of Mn (Ii) And Al (Iii).
...Show More Authors

New derivative molecular absorption spectrophotometric methods have been developed for the determination of Al (III) , Mn (II) , individually and binary mixtures . The aim of this model of study is to obtain analytical results characterized by adequate standard of analytical figures of merits through application of derivative Spectrophotometry (dnA/d?n). The two metals acetyl acetonates are chemically stable and are widely used as catalysts . Where Interferences are probable due to very close or nearby peaks or Summits, the Zero – Crossing derivative measurement technique is used to avoid interfering effects between two metals pairs.

View Publication Preview PDF
Crossref
Publication Date
Sun Apr 30 2023
Journal Name
Journal Européen Des Systèmes Automatisés
Developing Multiple-Actuator Pneumatic Circuits Using the Karnaugh Maps Designing PLC Controlled
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Sun Sep 01 2024
Journal Name
Nasaq
Analyzing Multiple Intelligences Theory in Teaching New Headway Upper-Intermediate EFL Textbook
...Show More Authors

The birth of Multiple Intelligence (MI) theory has revolutionized traditional education since the twentieth century. Howard Gardner, the pioneer of this theory, believed that each learner has a unique way of acquiring information. This paper investigates how the New Headway Plus for Upper-Intermediate-Third Edition, a standard EFL textbook in Iraqi universities, can cater to the diverse MI profiles of Iraqi EFL learners. It evaluates the success or failure of senior undergraduates in actively engaging with different learning styles and activities in the classroom. The study maps the distribution of nine distinct modes of MI theory across all 12 Units_ Logic/Mathematical, Verbal/Linguistic, Musical, Bodily/Kinesthetic, Visual/Spatial, Natura

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Proposed method to estimate missing values in Non - Parametric multiple regression model
...Show More Authors

In this paper, we will provide a proposed method to estimate missing values for the Explanatory variables for Non-Parametric Multiple Regression Model and compare it with the Imputation Arithmetic mean Method, The basis of the idea of this method was based on how to employ the causal relationship between the variables in finding an efficient estimate of the missing value, we rely on the use of the Kernel estimate by Nadaraya – Watson Estimator , and on Least Squared Cross Validation (LSCV) to estimate the Bandwidth, and we use the simulation study to compare between the two methods.

 

View Publication Preview PDF
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
Time and finance optimization model for multiple construction projects using genetic algorithm
...Show More Authors
Abstract<p>Construction contractors usually undertake multiple construction projects simultaneously. Such a situation involves sharing different types of resources, including monetary, equipment, and manpower, which may become a major challenge in many cases. In this study, the financial aspects of working on multiple projects at a time are addressed and investigated. The study considers dealing with financial shortages by proposing a multi-project scheduling optimization model for profit maximization, while minimizing the total project duration. Optimization genetic algorithm and finance-based scheduling are used to produce feasible schedules that balance the finance of activities at any time w</p> ... Show More
View Publication
Scopus (5)
Crossref (5)
Scopus Clarivate Crossref