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Absorption Coefficient of a Double-Layer Inhomogeneous Micro-perforated Panel Backed with Multiple Cavity Depths
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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.

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Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Reduce Waiting Times in the Multiple Server queuing model (M, M, C) (FCFS, ∞, ∞) "Model Proposal"
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   The research aims to propose a plan to reduce the waiting times in the Multiple Server queuing model (M, M, C) (FCFS, ∞, ∞), and adopt this plan, mainly on the arrival rate (λ), some process have been achieved in order to reduce the arrival rate per service channel that should  reduces the overall waiting time in the system.  This research is on two sections where the first deals with theory and how it has been approved the proposed method in theory and in mathematical equations as well as the second section, which dealt with the practical goal of applying the proposed method and comparing it with the traditional way, which was followed in calculating the performance measures in this model.  
&

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Publication Date
Mon Jul 31 2017
Journal Name
Journal Of Engineering
Rigid Trunk Sewer Deterioration Prediction Models using Multiple Discriminant and Neural Network Models in Baghdad City, Iraq
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Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study on the Impact of External Geometrical Shape on Free and Forced Convection Time Dependent Average Heat Transfer Coefficient during Cooling Process
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In this research, an experimental study was conducted to high light the impact of the exterior shape of a cylindrical body on the forced and free convection heat transfer coefficients when the body is hold in the entrance of an air duct. The impact of changing the body location within the air duct and the air speed are also demonstrated. The cylinders were manufactured with circular, triangular and square sections of copper for its high thermal conductivity with appropriate dimensions, while maintaining the surface area of all shapes to be the same. Each cylinder was heated to a certain temperature and put inside the duct at certain locations. The temperature of the cylinder was then monitored. The heat transfer coefficient were then cal

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Publication Date
Wed Oct 01 2008
Journal Name
Journal Of The Faculty Of Medicine Baghdad
A study of 124 with cases carpal tunnel syndrome
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Background: carpal tunnel syndrome (CTS) a relatively common disease affecting ♀ more than ♂, usually at the age between 40 -60 , diagnosed by EMG & NCS, treated when moderate
to severe by surgical decompression of the median nerve.
Objective: To study the role of surgery in the management of CTS.
Patients & method: 124 patients collected from the neuro-surgical departments of the specialized surgical hospital from August 2001 till March 2007, all patients studied thoroughly
regarding age, sex, associated diseases, clinical features, EMG studies, surgery & out come & follow up for at least one year.
Results & discussion: there was around 2:1 ♀:♂ , with age predomena between 40-60

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Publication Date
Tue Nov 30 2021
Journal Name
Iraqi Journal Of Science
Manufacture a Battery-like Supercapacitors with Electrodes of Graphene
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A graphene-based battery-like supercapacitors (SC) were manufactured. The prime objective of this research was to use environmentally friendly and natural materials as possible for the SC electrodes, electrolytes and the separators. The SC were designed in cells like batteries, three types of plastic cases were used as SC cells; the electrode and electrolyte materials were mixed together and a solution formed and placed in the designed cell. The electrode material was graphene powder with different weights mixed with different volumes of electrolytes (which were: lemon juice, apple vinegar, H2SO4 and HNO3), and the separators used were Polytetrafluoroethylene polymer (PTFE) and cellulose based parchment paper (PP).
Charging circuit wa

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Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
A New Green Approach of CFIA Technique for Direct Assay with a High Throughput of Sulfamethoxazole Drugs Using Condensation Reaction with NQS Agent
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A new design of manifold flow injection (FI) coupling with a merging zone technique was studied for sulfamethoxazole determination spectrophotometrically. The semiautomated FI method has many advantages such as being fast, simple, highly accurate, economical with high throughput . The suggested method based on the production of the orange- colored compound of SMZ with (NQS)1,2-Naphthoquinone-4-Sulphonic acid Sodium salt in alkaline media NaOH at λmax 496nm.The linearity range of sulfamethoxazole was  3-100  μg. mL-1, with (LOD) was 0.593 μg. mL-1 and the RSD% is about 1.25 and the recovery is 100.73%. All various physical and chemical parameters that have an effect on the stability and development of

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
The role of the plasmid content in multiple resistance to antibiotics Life in isolated Rthomh of cases of diarrhea in children
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Was conducted neutralize content Albulamedi for local isolates using Alacardan dye orange selection experience showed loss of local isolates resistant life antibiotic ampicillin, chloramphenicol

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Publication Date
Wed Oct 01 2008
Journal Name
Journal Of The Faculty Of Medicine Baghdad
A STUDY OF LEPTIN & LIPID PROFILE IN A SAMPLE OF IRAQI PATIENTS WITH KNEE OSTEOARTHRITIS.
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Background: New data suggests that joint damage in Knee Osteoarthritis (KOA) may be caused by systemic factors like adipose tissue products; Adipokines, which may provide a
metabolic link between obesity & KOA. Recently, one of the known adipokines named LEPTIN has been linked to KOA because it can be detected in serum & synovial fluid of
patients with KOA.
Objective: To evaluate the contribution of Leptin & serum lipids to the pathophysiology of Osteoarthritis in Iraqi patients with Knee OA.
Subjects& Methods: The study was carried on 90 subjects divided into four groups: Knee Osteoarthritis cases group (n=60). Control group (n=30). Obese subjects group (n=60).
Non-obese subje

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Publication Date
Mon Mar 23 2020
Journal Name
Journal Of Engineering
Experimental Investigation of Thermal Performance of a Solar Chimney Provided with a Porous Absorber Plate
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Experimental investigation of the influence of inserting the metal foam to the solar chimney to induce natural ventilation are described and analyzed in this work. To carry out the experimental test, two identical solar chimneys (without insertion of metal foam and with insertion of metal foam) are designed and placed facing south with dimensions of length× width× air gap (2 m× 1 m× 0.2 m). Four incline angles are tested (20o,30o,45o,60o) for each chimney in Baghdad climate condition (33.3o latitude, 44.4o longitude) on October, November, December 2018. The solar chimney performance is investigated by experimentally recording absorber pl

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Publication Date
Wed Jan 08 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Measurement of salivary Immunoglobulin A of participants with a healthy, gingivitis and chronic periodontitis conditions
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Background: Secretory Immunoglobulin A (SIgA) is a subclass of Immunoglobulin A (IgA), It is an antibody that plays an important role in mucosal immunity. It is the main immunoglobulin found in mucous secretions from mammary glands, tear glands and salivary glands, every pathologic process in the body involves the immune system, and periodontal inflammation is one of them and is not an exception. Material and methods: this study was consisted of 60 healthy male participants of an age ranged between (35-50) years old ; 25 of them with generalized moderate chronic periodontists(Clinical Attachment Loss equal to 3-4mm at ≥ 30% of the sites; 20 participants with plaque induced gingivitis and 15 participants had clinically healthy pe

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