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.
We studied the relationship between DNA sequencing of interleukin-10 (IL-10) gene promoter for -1082 (A/G) and -592 (A/C) positions with the concentration of IL-10 in blood serum of Iraqi children with type 1 diabetes mellitus (T1D). Fifty blood serum samples collected from children with age ranged between 7-12 years. Thirty-five blood samples collected from patient children with T1D, and compared with 15 healthy children age matched as control sample. The results revealed decreasing in anti-inflammatory IL-10 concentration in T1D patient’s blood serum (0.068 Pg/ml) as compared with the control sample (0.111 Pg/ml). No significant differences were found in interleukin concentration between the studied samples when they analyzed with the M
... Show MoreA cost-effective and efficient detector was created to conduct thorough turbidimetric measurements by reaction of Co (II) ion with calcium ferro cyanide to form bright green particulate, using the method of continuous flow injection analysis, the use of NAG-5SX1-1D-SSP Analyzer in determining cobalt (II) ion in a test for the validity of the new design. The NAG-5SX1-1D-SSP Analyzer is composed of five irradiation sources of white snow leds having the diameter of 10 mm with one solar cell of 55 mm length, 13.5 mm width. Using a selector switch to select the optimum voltage to be used which was 2.7 VDC. Under conditions of optimization, cobalt (II) ion was determined at 0.005–20 mmol. L–1(n = 23) while linearity dynamic range 0.005–7 mm
... Show MoreIn this paper, we investigate the basic characteristics of "magnetron sputtering plasma" using the target V2O5. The "magnetron sputtering plasma" is produced using "radio frequency (RF)" power supply and Argon gas. The intensity of the light emission from atoms and radicals in the plasma measured by using "optical emission spectrophotometer", and the appeared peaks in all patterns match the standard lines from NIST database and employed are to estimate the plasma parameters, of computes electron temperature and the electrons density. The characteristics of V2O5 sputtering plasma at multiple discharge provisos are studied at the "radio frequency" (RF) power ranging from 75 - 150 Wat
... Show MoreThe corrosion behavior of mild sleet in saturated aerated and de-aerated Ca(OH)2 solution was investigated using electrochemical measurements. The work was carried out with small coupons immersed in solutions containing different quantities of NaCl in presence of various NaN02 concentrations as corrosion inhibitors. It has been found thal:(1 ) In presence of NaCl, the time required to reach O2 evolution potential in de-aerated Ca(OH)2 polarized at 10μA/cm 2 is function of inhibitor concentration and it becomes lass as NaN02 increases compared with zero presence indicating the effectiveness of N
... Show MoreAnkylosing spondylitis (AS) represents one kind of advanced arthritis formed via inflammatory stimuli long-term in the spin‘s joints. Interleukin (IL)-29 (interferon- lambda1(IFN- λ1)), interleukin (IL)-28A (interferon- lambda 2 (IFN- λ2)) and interleukin (IL)-28B (interferon- lambda 3(IFN-λ3)) are three interferon lambda (IFN- λs) molecules that have recently been identified as new members of the IFN family. IL-28B expression in ankylosing spondylitis (AS) is not well understood. 150 male healthy controls ((HC) and 160 males with AS as patients group participated in this study. Serum level and gene polymorphism were assessed using an enzyme-linked immunosorbent assay and Sanger sequencing for IL-28B, respectively. The results showed
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