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.
Abstract A description study was carried through out the present study aimed to assess health education provided by nurses to patient with gall stone "obstructive jaundice". The study was conducted at 4 teaching hospital, Baghdad teaching hospital, Al-Karama teaching hospital, Al-Yarmook teaching hospital, Al-Kendy teaching hospital where choloecystectomy was performed, in the period from first of June 2004 to end of July 2004. Data were collected through the use of questionnaire an interview from which was developed for the purpose of the present study. A non-probability (purposive) sample which was consist
The concept of the separation worry is considered one of the common disorders in children. The causes and effects of this worry influence the child mental and cognitive ability and the child ability to communicate with others, has friendship and the ability of adaptive with the environment, peers and teachers and it also influences the child's academic and social performance.
The importance of this study is represented in handling the working memory, one of important subject in cognitive psychology. Many universal studies show that the working memory is very important in several daily functions such as continuous attention, followinstructions, implement instructions of many steps, the moment of information remembering and keep focusin
Over the last 40 years, rate of cesarean delivery has risen from less than10% to over 30% around the world, and almost simultaneously a 10-foldraise in the incidence of placenta accrete spectrum. Fine coordinationamong vascular endothelial growth factor, soluble fms-like tyrosine kinase1 and placental growth factor is important for normal placentaldevelopment and trophoblast invasion. To measure and compare the levelsof circulating vascular endothelial growth factor, placental growth factorand soluble fms-like tyrosine kinase 1 in pregnant women with placentaaccreta to a control group. A case control study which involved one hundredpregnant females were recruited from the Obstetric ward in BaghdadTeaching Hospital who were pregnant with 28
... Show MoreHelicobacter pylori (HP) is the etiopathogenic agent of gastric and duodenal disorders ranging from gastritis to malignancy. It is also associated with many extraintestinal diseases, including cardiovascular disease and its associated risk factors. To evaluate the link between HP infection and some cardiovascular risk factors by studying the effects of HP infection on body mass index, blood pressure, and serum lipid profile among patients having gastritis with and without HP infection. A crosssectional study included 1214 patients who had gastritis diagnosed by gastroscopy examination. Those patients were in the age range of 30-65 years and they were divided according to their gender into 725 females and 489 males depending on the 1
... Show MoreThe organization uses many techniques and methods to ensure that they will succeed and adapted with velocity change in the internal and external environment by decision taking, especially strategic decisions.
Strategic decisions are very important for organization success because it can predict the future and deal with uncertainty, in this circumstances they need accurate and comprehensive information to make effective strategic decision.
To achieve that purpose it must owned successful Strategic Information System ( SIS ) and determined the critical success factors for this system ,which can assisted the worker to focus on the important activities to develop it.
... Show MoreChronic kidney disease (CKD) is a permanent loss of kidney function which is diagnosed when the glomerular filtration rate (GFR) is under 60 ml\min\1.73m2 for more than three months. The present study was conducted at Kidney Transplant and Dialysis Center in the Medical City in Baghdad from October 2018 to April 2019. Sixty CKD patients with an age ranged of 40 to 65 years and 25 healthy subjects were involved in this study. Blood samples were collected to evaluate the levels of kidney function parameters and thyroid hormones. The levels of urea, creatinine and uric acid showed highly significant (p ≤ 0.01) increases in CKD patient in comparison with the control group, while the values of GFR and creatinine clearance showed highly
... Show MoreSystemic Lupus Erythematosus (SLE) is a multifactorial chronic systemic autoimmune disease. It is characterized by a lack of immune tolerance to autoantigens such as nuclear antigens. The aim of the study is to assess the interferon-alpha (IFN-α) serum level in Iraqi patients with SLE and determine its potential relation to different clinical and laboratory parameters and disease activity. 100 SLE patients were all females and with a mean of age 31.3 ± 10 years (16-63years) and disease duration of 5.8 ± 3.7years (1 month to 15 years). The average of SLEDAI score ranged from 2 to 22 with a mean of (8.53 ±3.42). Proteinuria, ESR, creatinine and AST were significantly higher (65% vs. 10% and 0.62±0.11 vs. 0.70±0.14 mg/dl resp
... Show MoreHelicobacter pylori (H. pylori) is one of the most common human pathogens in the world. Several studies that have investigated the correlation between H. pylori infection and type 2 diabetes mellitus (DM) found that H. pylori infection is more frequent in the patients, while the results of other studies were unclear. This paper aims to investigate the interrelation between the infection with H. pylori and type 2 DM in Dohuk governorate, Iraq. Eighty four diabetes patients (41 males, 43 females) and 92 healthy controls were involved in this study. H. pylori status was assessed in serum samples by using ELISA test. Out of the 84 patients,
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