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
Fri Dec 29 2017
Journal Name
Al-khwarizmi Engineering Journal
A Study Of Strengthening Circular Diaphragm By Ring-Shaped Concentric Ribs
...Show More Authors

 This paper deals with the determination of stresses and deflections of clamped circular diaphragm strengthened by one or two ring-shaped concentric ribs, under uniform static and dynamic pressures. The simulation has been achieved by using the well-known engineering software finite element package MSC/NASTRAN

 As a design study, the effect of using a clamped ring, and the effect of using a ring-shaped rib on both surfaces of diaphragm instead of one, has been discussed in this work. To show the effectiveness of this study, results of this work have been compared with  published data [1].

In  the  conclusion,  the  authors underline  the  validity of  the&n

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Protective Effect of Vitamin A against Oxidative Stress Caused by Methotrexate
...Show More Authors

Methotrexate (MTX), a folate antagonist agent, is mainly used in treatment of
malignant tumors and autoimmune diseases. The present study was undertaken to
determine whether antioxidant vitamin (vitamin A) could ameliorate methotrexateinduced
oxidative stress in male rabbits. Twenty male rabbits were randomly
assigned into four groups. Group 1: control group, Group 2: MTX-treated group
(received 20 mg/kg MTX intraperitoneally), Group 3: Vit.A treated group received
5000 IU Vit.A orally) and Group 4: MTX+Vit.A treated group received MTX 20
mg/kg plus 5000 IU vit.A). After 4 weeks of treatment, blood samples were
collected by cardiac puncture to determine the serum malondialdehyde (MDA), as a
good indicator for l

... Show More
View Publication Preview PDF
Publication Date
Tue Jul 01 2008
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A NEW SPECIES OF COSMINA ROB.-DESVOIDY, 1830 IRAQ (DIPTERA : CALLIPHORIDAE)
...Show More Authors

This study includes a detailed morphological description of Cosmina baghdadensis sp. nov.
from Iraq.
Many characters are used in identification especially chaetotaxy and male genetalia.
Locality, host plant, and data of collection were given.

View Publication Preview PDF
Publication Date
Tue Feb 01 2022
Journal Name
Iraqi Journal Of Science
A Study of compression strength and flexural strength for Polymer Concrete
...Show More Authors

Polymer concrete were prepared by mixing epoxy resin with sand particles in three different grain size (150-300) , (300-600 ) and (600- 1200) μm respectively. The percentage of epoxy was 15%, 20 %, 25% and 30% wt of the total weight. Compression strength and flexural strength tests were carried out for the prepared samples.
The percentages of epoxy resin at 20% wt and 25% wt showed best mechanical properties for all grain sizes. These percentages were adopted to fill the voids between particles sand have two different size ranges (150-600) μm and {(150-300) & (600-1200)} μm respectively to obtain more dense material. The results showed that the strength of polymer composite at 20% resin is higher than 25% resin.

View Publication Preview PDF
Publication Date
Wed Jun 30 2010
Journal Name
Al-kindy College Medical Journal
A prospective study of colonoscopic examination at al-kindy teaching hospital
...Show More Authors

Background: Fiber-optic endoscopy is an important
investigation of the large intestine, whether or not the
radiologist (barium enema) has discovered a lesion in
the bowel. Colonoscopy affords a unique opportunity
to direct visualization of entire colonic mucosa. At
the same time, the physician can obtain biopsy specimens, remove polyps, and decompress volvuli.
Most experienced endoscopists and well prepared
patients can reach the cecum in over 90% of patients.
If colonoscopy is properly performed, it has a low
risk of complications, such as perforation and bleeding.
Methods: A total of 70 consecutive patients admitted
to Endoscopy department at Al-Kindy Teaching hospital from September- 2008 to July-2009.

... Show More
View Publication Preview PDF
Publication Date
Sun Sep 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
A Study in to the Dynamic Behavior of Packed Distillation Column
...Show More Authors

The study of the dynamic behavior of packed distillation column was studied by frequency response analysis using Matlab program. A packed distillation column (80 mm diameter) (2000 mm height) filled with glass packing (Raschig Rings 10mm), packing height (1500 mm) has been modified for separation of methanol-water mixture (60 vol%). The column dynamic behavior was studied experimentally under different step changes in, feed rate (±30%), reflux rate (±22%), and reboiler heat duty (±150%), the top and bottom concentration of methanol were measured. A frequency response analysis for the above step response was carried out using Bode diagram, the log modulus and the phase angle were  used to analyze the process model. A Matlab progra

... Show More
View Publication Preview PDF
Publication Date
Sat Jun 15 2024
Journal Name
Journal Of Legal Sciences
Criminal Protection of Human Genome “Human Gene Editing as a Model”
...Show More Authors

Lawful protection of the human gene conceded a moral concern regarding the future of existence human. After the discovery of the human genetic map, scientific experiments and research related to the human gene increased, negative applications of genetic engineering  in particular that violate essential human rights,  the right to human dignity to be specific. These practices represent actual challenges to the existence and diversity of current and future generations. Therefore, the presence of legal rules at the domestic and global levels is an absolute necessity to prohibit these threats and determine civil and criminal accountability for those who infringe any laws related to this issue.

View Publication
Publication Date
Wed Jun 30 2010
Journal Name
Al-kindy College Medical Journal
A prospective study of colonoscopic examination at al-kindy teaching hospital
...Show More Authors

Background: Fiber-optic endoscopy is an important
investigation of the large intestine, whether or not the
radiologist (barium enema) has discovered a lesion in
the bowel. Colonoscopy affords a unique opportunity
to direct visualization of entire colonic mucosa. At
the same time, the physician can obtain biopsy specimens, remove polyps, and decompress volvuli.
Most experienced endoscopists and well prepared
patients can reach the cecum in over 90% of patients.
If colonoscopy is properly performed, it has a low
risk of complications, such as perforation and bleeding.
Methods: A total of 70 consecutive patients admitted
to Endoscopy department at Al-Kindy Teaching hospital from September- 2008 to July-2009.

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 16 2022
Journal Name
Iraqi Journal Of Science
A New Record of Saxifraga afghanica Aitch. & Hemsl. (Saxifragaceae) in Iraq
...Show More Authors

Saxifraga afghanica Aitch. & Hemsl. is a new addition to the Saxifragaceae family in Iraq, from Qandil mountain (north-east of Erbil) within Rowanduz district (MRO). The collected specimens have different characteristics. S. afghanica is perennial, herb, with crowded shoots forming cushions, many branched. Leaves sessil, narrowly oblong, narrowly oblong-lanceolate, oblanceolate or sub-spatulate, glabrous, entire, ciliated at lower half, apex leaves aggregated into a rosette, chalk glands (pits at the leaves apex) 5. Bracts cultrate, linear or narrowly oblong, glandular-pubescent. Inflorescence corymbose cyme, flowers (3-5), white-pink, stamens 10, ovary semi-inferior, styles 2, divergent, recurved at the top. Capsule globose-semi glo

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 01 2016
Journal Name
2016 Ieee Symposium Series On Computational Intelligence (ssci)
A fusion of time-domain descriptors for improved myoelectric hand control
...Show More Authors

View Publication
Scopus (33)
Crossref (27)
Scopus Clarivate Crossref