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.
The research aimed at studying the inhibitive effect of the hot watery dry and ethanolic ginger(85%) and fragrant oil which are added in concentrates of o.o25, o.o5o and 0.1g / 100g respectively in the growth of bacteria and molds. The results of the initial chemical diagnosis showed containment of ginger roots extract on. Alkaloids, Glycosides, Flavonoids and Suponins. The highest inhibitive effect of the bacteria reached the concentrate . 0.1% of the oil extract then the concentrate 0.050% of the ethanolic hot extract follows it. While 0.1% was the least inhibitive concentrate for the hot watery extract. But the inhibitive effect of the hot oily and alcoholic extracts in the numbers of molds colonies was 0.025%, when the concentrate 0.1%
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This study is studied one method of estimation and testing parameters mediating variables in a structural equations model SEM is causal steps method, in order to identify and know the variables that have indirect effects by estimating and testing mediation variables parameters by the above way and then applied to Iraq Women Integrated Social and Health Survey (I-WISH) for year 2011 from the Ministry of planning - Central statistical organization to identify if the variables having the effect of mediation in the model by the step causal methods by using AMOS program V.23, it was the independent variable X represents a phenomenon studied (cultural case of the
Obesity is a common disease that resulted from over-nutrition in adults and children. It rarely causes damage to the centers of food in the brain. Obesity is defined as an increased body weight from its natural limit which is resulted from the accumulation of excessive amounts of fatty tissue incredibly up to 20% in males, 30 % in females unless this increase is not due to an increase in muscles as in athletes or accumulation of water in the body which is resulted from Mesothelioma or the magnitude of the skeleton.Obesity is the increase of the total average of fat in the body compared to other tissues, which causes an increasing body weight, thereby increasing body mass. The fatty child has an increase in the stored fatty layer under th
... Show MoreThe researchers have a special interest in studying Markov chains as one of the probability samples which has many applications in different fields. This study comes to deal with the changes issue that happen on budget expenditures by using statistical methods, and Markov chains is the best expression about that as they are regarded reliable samples in the prediction process. A transitional matrix is built for three expenditure cases (increase ,decrease ,stability) for one of budget expenditure items (base salary) for three directorates (Baghdad ,Nineveh , Diyala) of one of the ministries. Results are analyzed by applying Maximum likelihood estimation and Ordinary least squares methods resulting
... Show MoreBackground: One of the recommended methods for reducing aerosol contamination during the daily regular usage of high-speed turbine and ultrasonic scaling is the use of preprocedural mouth rinse. Several agents have been investigated as a preprocedural mouth rinse. Chlorhexidine significantly reduce the viable microbial content of aerosol when used as a preprocedural rinse. Studies have shown that cetylpridinum chloride (CPC) mouthwash is equally effective as chlorhexidine in reducing plaque and gingivitis. This study compared the effect of 0.07% CPC to 0.2% chlorhexidine gluconate (CHX) as preprocedural mouth rinses in reducing the aerosol contamination by high-speed turbine. Materials and Methods: 36 patients were divided into three gro
... Show MoreThe study aimed to reveal the level of knowledge and tendencies of high- study students specializing in curriculum and teaching methods at King Khalid University towards harmonious strategies with brain-based learning (BBL). And Then, putting a proposed concept to develop knowledge and tendencies of high-study students specializing in curriculum and teaching methods at King Khalid University towards harmonious strategies with Brain-based learning (BBL). For achieving this goal, a cognitive test and a scale of tendency were prepared to apply harmonious strategies with brain-based learning. The descriptive approach was used because it suits the goals of the study. The study sample consisted of (70) male and female students of postgraduate
... Show MoreBackground and Objectives: Urinary tract infections (UTIs), among a wide range of microbial infections, are of a double-edged worry with health-care and economic implications. They are serious diseases that can influence various parts of the urinary tract. The aim of this study was characterization of the enteric bacteria isolated from urine of human UTIs and studying their antimicrobial sensitivity. Materials and methods: A total of 50 urine samples were collected from patients with UTIs of both genders. The isolates identification was done using routine diagnostic methods and confirmed by Vitek2. Antimicrobial susceptibility was done against 10 antimicrobials. Results: Both genders of human were found to suffer from urinary tract problems
... Show MoreThis study aims to formulate an alternative solution for Formalin for preserving fish as study specimens for long periods. The main reason for finding a solution instead of formalin is to get rid of the negative effects of this solution on those who work with it, as well as to better preserve the bodies of fish. Hence, three new solutions were proposed to replace formalin. Thus, Formalin, in turn, may enter the composition of a small part of these solutions to give better results and for long periods of keeping specimens. All solutions prepared in this study participated in being acidic as in formalin. Two solutions succeeded in compensating for the use of formalin in preserving fish
This current study aims to:
1st: The recognizing of Alexithymia level for 6th grade students (Study Specimen) through the next Zero Hypothesis:1. There are no statistically significant differences at (0.05) level between the arithmetic mean of the specimen degrees as a whole and the central assumption for the scale of the lack in emotions expression
2. There are no statistically significant differences at (0.05) level between the arithmetic mean of the male students specimen and the arithmetic meanc of the female students specimen for the scale of Alexithymia.
2nd: ldentification the level of the emotional intelligence among 6th grade students (Study Specimen) through the next Zero Hypothesis:
1) There are no statistically si
Background: The etiology of Systemic lupus erythematosus seems to be multifactorial including environmental as well as genetic factors. The genetic predisposition was supported by the occurrence of Systemic lupus erythematosus in more than one member of a family as well as in identical twins.
Aim of the study: To determine the human leukocyte antigen typing class I (A and B) in patients with Systemic Lupus Erythematousus disease.
Methods: Patients group consisted of 44 Iraqi Arab Muslims patients with Systemic lupus erythematosus disease who presented to Baghdad Medical City from January 2010 to January 2012 from Baghdad Province. The second control group consisted from 80 Iraqi Arab Muslims volunteers from hospital employees and t