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.
Chloroquine and Hydroxychloroquine drugs are widely prescribed for malaria disease. Since the end of 2019, humans have been under threat due to a disease called (COVID-19), which was first reported in China. Many methodical approaches have been reported to quantify chloroquine and hydroxychloroquine in blood, urine, plasma, serum, and pharmaceutical dosage form. Some of these techniques are spectrophotometry, liquid chromatography with a mass detector, gas chromatography, and ultra-performance, high-performance liquid chromatography (HPLC), in addition to electrochemical methods. This literature review discusses various analytical methods for the determining hydroxychloroquine and chloroquine.
Bilosomes are nanocarriers that contain bile salts in their vesicular bilayer, thereby enhancing their flexibility and durability in the gastrointestinal tract. Unlike conventional vesicular systems they provide distinct advantages such as streamlined manufacturing procedures, cost efficiency, and improved stability. The main objective of this study was to attain a comparison of the pharmacokinetic parameters of nisoldipine (NSD) after administering an ordinary NSD suspension and an NSD-loaded bilosome suspension. The study used 60 Swiss albino rats weighing 200±15 g and divided into two groups (n=30 each). A dose of 2.2 mg/kg of NSD was administered from the ordinary NSD suspension to the rats of the first group and the same dose
... Show MoreIn project management process, the objective is to define and develop a model for planning, scheduling, controlling, and monitoring different activities of a particular project. Time scheduling plays an important role in successful implementation of various activities and general outcome of project. In practice, various factors cause projects to suffer from time delay in accomplishing the activities. One important reason is imprecise knowledge about time duration of activities. This study addresses the problem of project scheduling in uncertain resource environments, which are defined by uncertain activity durations. The study presents a solution of the levelling and allocation problems for projects that have some uncertain ac
... Show MoreIn this research, main types of optical coatings are presented which are used as covers for solar cells, these coatings are reflect the infrared (heat) from the solar cell to increase the efficiency of the cell (because the cell’s efficiency is inversely proportional to the heat), then the theoretical and mathematical description of these optical coatings are presented, and an optical design is designed to meet this objective, its optical transmittance was calculated using (MATLAB R2008a) and (Open Filters 1.0.2) programs
When a vehicle is left parked in the sun for an extended period, the gathered heat causes damage to several interiors within the cabin and causes discomfort for people and animals left inside the car. In the present work, the effect of the orientation of a parked white minibus on temperature distribution and cooling load calculation is studied experimentally in an open environment. Two different cases were studied facing south and facing east. For several hours, the temperature inside the car cabin had been monitored and measured at five separate locations. The cooling load calculations are carried out based on the experimental measurements. The results show that the overheating of parked cars always happens as a result
... Show Morethin films of se:2.5% as were deposited on a glass substates by thermal coevaporation techniqi=ue under high vacuum at different thikness
Background: Serum adiponectin is a hormone of adipose tissue that activateslipid metabolism and exertsphysiological functions. Its level usually fluctuates in several metabolic diseases,including renal insufficiency and diabetes; it loses its protective role against diseases and becomes a potentially risk factor for erythroid abnormalities.
Objectives: The study was designed to assess the association between adiponectin hormone, blood erythroid and various parameters in groups of patients.
Method:The study included 130 patientsand 42 healthy subjects. Parameters of serum adiponectin, erythropoietin (EPO), red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), ren
... Show More