Micro-perforated panel (MPP) absorber is increasingly gaining popularity as an alternative sound absorber in buildings compared to the well-known synthetic porous materials. A single MPP has a typical feature of a Helmholtz resonator with a high amplitude of absorption but a narrow absorption frequency bandwidth. To improve the bandwidth, a single MPP can be cascaded with another single MPP to form a double-layer MPP. This paper proposes the introduction of inhomogeneous perforation in the double-layer MPP system (DL-iMPP) to enhance the absorption bandwidth of a double-layer MPP. Mathematical models are proposed using the equivalent electrical circuit model and are validated with experiments with good agreement. It is revealed that the DL-iMPP produces a wider half-absorption bandwidth compared to the conventional homogeneous double-layer MPP. The absorption bandwidth to higher frequencies can be effectively controlled by reducing the air cavity between the iMPPs and to the lower frequencies by increasing the back cavity depth at the second layer.
Purpose: The research aims to explore the impact Business Intelligence System (BIS) and Knowledge Conversion Processes (KCP) in the Building Learning Organization (LO) in KOREK Telecom Company in Baghdad city.
Design/methodology/approach: in order to achieve the objectives of the research has been the development of a questionnaire prepared for this purpose and then has tested the search in the telecommunications sector, representatives of one of the telecommunications companies in Baghdad city, has therefore chosen KOREK Telecom company as a sample for research, and the choice was based on the best standard international companies to serve mobile communications in terms o
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The problem of research on the study of political debate programs in the Iraqi satellite channels, in the "People decide" program by Afaq channel and " electoral competition " by Fallujah channel), and its importance for the community and researchers in the scientific field, as new programs to enter the Iraqi media after we have been the world media a lot in this area at the academic and practical levels (The field), and seeks to find out what the technical construction of the programs of political debates in Iraqi satellite channels and methods of construction and methods of employment used by the technical elements in the presentation of the programs and The study adopted the surve |
For aspirin estimated, a molecularly imprinted polymer MIP-ASP electrodes were generated by electro-polymerization process, the electrodes were prepared by combining the template (aspirin) with (vinyl acetate (VA), 1-vinylimidizole (VIZ) as a functional monomer and N, N-methylene bisacrylamide (MBAA) as crosslinkers using benzoyl peroxide (BPO) as an initiator. The efficiency of the membrane electrodes was analyzed by differential pulse voltammetry (DPV). Four electrodes were synthesized using two different plasticizers, di-butyl sebacate (DBS), di-octyl phthalate (DOP) in PVC matrix. Scanning electron microscopy (SEM) was used to describe the generated MIP, studying the electrodes properties, the slope, detection limit, and life
... Show MoreThis study aimed to identidy the role of a professional social worker practice specialist in the field of social care for Corona patients, in light of some demographic variables such as (gender, marital status, economic status,), through a field study at the Iraqi Ministry of Social Affairs. A random sample of (50) social workers in the Iraqi Ministry of Social Affairs in various places affiliated with the ministry was chosen. a questionnaire developed by the researcher about the role of the social worker in the field of social care for Corona patients was administered to the study sample to collect the needed data. The results showed that there is a positive statistically significant correlation relationship at the level (0.01) between
... Show MoreConstitute a planning problem on the basis of personal experience and self-governance in the service organizations away from quantitative scientific method in planning an anchor and a platform, who made a recent research study, analysis and interpretation through scientific methodology adopted which formed its contents, The research aims to identify the true reality of production planning in service organizations, specifically in the Baghdad Hotel as a society to look, in order to assess the best strategy through the standard cost of the strategies of tracking and settlement to cope with developments on services demand changes, Search results confirmed that the settlement rates of production strategy is the best strategy in accordance wi
... Show MoreDarcy-Weisbach (D-W) is a typical resistance equation in pressured flow; however, some academics and engineers prefer Hazen-Williams (H-W) for assessing water distribution networks. The main difference is that the (D-W) friction factor changes with the Reynolds number, while the (H-W) coefficient is a constant value for a certain material. This study uses WaterGEMS CONNECT Edition update 1 to find an empirical relation between the (H-W) and (H-W) equations for two 400 mm and 500 mm pipe systems. The hydraulic model was done, and two scenarios were applied by changing the (H-W) coefficient to show the difference in results of head loss. The results showed a strong relationship between both equations with correlation coefficients of 0.999,
... Show MoreMicrobial activity of Ellagic acid when mixed with some types of candy toward Streptococcus mutans microorganism was studied. The main purpose of carrying out this study is to produce a new type of candy that contains Ellagic acid in addition to xylitol instead of sucrose to prevent dental caries. The results show that the inhibitory action of Ellagic acid was more effective when mixed with this type of candy for the purpose of reducing Streptococcus mutans microorganisms, while sensory evaluation was applied in this study to 20 volunteers to that candy sample evaluated which contain (5 mg/ml) Ellagic acid with 100g xylitol to determine consumers acceptability of this sample of candy. The results were expressed as mean value, slandered d
... Show MoreChronic periodontitis (CP) is an inflammatory disease affecting tooth supporting structures in response to bacterial dental plaque causing irreversible tissue destruction. Cyclooxygenase-2 (COX-2) is an effective mediator in the pathogenesis of periodontitis. Polymorphisms in the COX-2 gene may contribute to its overexpression and increased disease susceptibility. To evaluate the association between -1195 A/G single nucleotide polymorphism (SNP) in the promotor area of the cyclooxygenase-2(COX-2) gene and severity of chronic periodontitis in a sample of Iraqi population. -1195A/ G COX-2 SNP was investigated in 70 chronic periodontitis (CP) cases and 30 healthy controls. CP cases composed of 2 subgroups (35 moderate CP cases and 35 severe CP
... Show MoreThe objective of this experiment was to determine the effects of dietary supplementation with different fat sources on blood parameters of Japanese quail (Coturnix coturnix japonica). Eighty four 7-week old laying quail were randomly assigned to 4 treatment groups (21 birds per group) with 3 replicates for each treatment group and fed for three months on a commercial diet supplemented with 3% of either sunflower oil (T1), flax oil (T2), corn oil (T3) or fish oil (T4). The birds received water and feed ad libitum during the experiment. During the last month of experiment blood samples were collected fortnightly from each bird. The first blood samples collection was used to determine fresh blood parameters, while the second blood samples coll
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