The standard formulation of Wave Intensity Analysis (WIA) assumes that the flow velocity (U) in the conduit is <;<; the velocity of propagation of waves (c) in the system, and Mach number, M=U/c, is negligible. However, in the large conduit arteries, U is relatively high due to ventricular contraction and c is relatively low due to the large compliance; thus M is > 0, and may not be ignored. Therefore, the aim of this study is to identify experimentally the relationship between M and the reflection coefficient in vitro. Combinations of flexible tubes, of 2 m in length with isotropic and uniform circular cross sectional area along their longitudinal axes, were used to present mother and daughter tubes to produce a range of reflection coefficients. An approximately semi-sinusoidal pulse was generated at the inlet of the mother tube using a syringe pump, first in the condition of initial velocity, U 0 =0, and when U 0 >0 with steady flow to superimpose the pulse. Pressure (P) and Velocity (U) were measured in the mother tube, wave speed was determined using the foot to foot and PU-loops methods. The theoretical reflection coefficient, R t at M=0, has been compared to the experimental reflection coefficient, R at M>0, which was determined as dP-/dP+ as calculated using WIA. The function R(M) changes significantly with the geometrical and mechanical features of the connected tubes. In our experiments, R increased significantly with small values of M. In the range of M=0-0.02, R increased by 4-36%. Therefore, we conclude that M significantly affects the magnitude of reflections.
Used in the study especially calibrated Erwa to determine the number of neighborhood or the Alayoshi number of bacteria in the count modeling and casting method dishes in addition to using the drop method yielded significant results for a match between the methods used ..
Transference numbers of the aqueous zinc chloride and zinc sulphate solutions have been measured for the concentrations 0.03, 0.05, 0.07, 0.09 and 0.1 mol.dm-3at 298.15K, by using the modified Hittorf method. The dependence of transference number on concentration of each electrolyte was also investigated in an attempt to explain the value of the limiting transference number. The Longsworth method has been used for the extrapolation of zinc transference number in aqueous solutions, using the values of the limiting transference numbers of the appropriate values of the limiting equivalent conductance, it was possible to determine the corresponding values of the limiting ion conductance for the cations and anions of the electrolytes. The
... Show MoreThe rehabilitation of deteriorated pavements using Asphalt Concrete (AC) overlays consistently confronts the reflection cracking challenge, where inherent cracks and joints from an existing pavement layer are mirrored in the new overlay. To address this issue, the current study evaluates the effectiveness of Engineered Cementitious Composite (ECC) and geotextile fabric as mitigation strategies. ECC, characterized by its tensile ductility, fracture resistance, and high deformation capacity, was examined in interlayer thicknesses of 7, 12, and 17 mm. Additionally, the impact of geotextile fabric positioning at the base and at 1/3 depth of the AC specimen was explored. Utilizing the Overlay Testing Machine (OTM) for evaluations, the research d
... Show MoreIn this paper, we will study non parametric model when the response variable have missing data (non response) in observations it under missing mechanisms MCAR, then we suggest Kernel-Based Non-Parametric Single-Imputation instead of missing value and compare it with Nearest Neighbor Imputation by using the simulation about some difference models and with difference cases as the sample size, variance and rate of missing data.
The corrosion behavior of carbon steel at different Temperatures and in water containing different sodium chloride
concentrations under 3 bar pressure has been investigated using weight loss method . The carbon steel specimens were
immersed in water containing (100,400,700,1000PPM) of NaCl solution and under temperature was increased from
(90-120ºC) under pressures of 3 bar. The results of this investigation indicated that corrosion rate increased with NaCl
concentrations and Temperature.
The present work aims to study the efficiency of using aluminum refuse, which is available locally (after dissolving it in sodium hydroxide), with different coagulants like alum [Al2 (SO4)3.18H2O], Ferric chloride FeCl3 and polyaluminum chloride (PACl) to improve the quality of water. The results showed that using this coagulant in the flocculation process gave high results in the removal of turbidity as well as improving the quality of water by precipitating a great deal of ions causing hardness. From the experimental results of the Jar test, the optimum alum dosages are (25, 50 and 70 ppm), ferric chloride dosages are (15, 40 and 60 ppm) and polyaluminum chloride dosages were (10, 35 and 55 ppm) for initial water turbidity (100, 500 an
... Show MoreA cross-sectional study was conducted on 80 type 2 diabetic patients aged 20-60 years in Baghdad and 20 non diabetic persons as controls. Laboratory assessment of glucose related parameters; Fasting blood sugar (FBS), Glycated hemoglobin (HbA1c), Insulin and Insulin resistance (IR), renal function test; Blood urea, serum creatinine, Calcium (Ca) and Phosphorus (P), Calcium regulating hormones; Parathyroid hormone (PTH), calcitonin and vitamin D, cytokines, Adiponectin and Tumor necrosis factor (TNF-α) and comparison these parameters between patients and controls. The results: a high significant (p˂0.01) increase in FBG level in the patients (211.34 ± 11.20 mg/dl) as compared with control (85.89 ± 3.07 mg/dl). A high significant (p˂0.01
... Show MoreOne of the most important intellectual issues, which receive attention is the issue of modernity, it has occupied the scholars of all time. However, modern poetry used to have special care in Iraq and in the Arab countries .. it is not strange that the concept of modernity is linked to history .. or having history as the most important dimension of its dimensions .. because Arab poetry is historical and it is moving into an area of the past that is still active in terms of language and literary image .. When some poets found that changing and modernizing poetry became a necessity of evolution, and one of the fundamentals of modernization, the cultural impact did not respond to the desire of poets, and their impulse in modern poetry
... Show MoreShort Multi-Walled Carbon Nanotubes functionalized with OH group (MWCNTs-OH) were used to synthesize flexible MWCNTs networks. The MWCNTs suspension was synthesized using Benzoquinone (BQ) and N, N Dimethylformamide alcohol (DMF) in specific values and then deposited on filter paper by filtration from suspension (FFS) method. Polypyrrole (PPy) conductive polymer doped with metallic nanoparticles (MNPs) prepared using in-situ chemical polymerization method. To improve the properties of the MWCNTs networks, a coating layer of (PPy) conductive polymer, PPy:Ag nanoparticles, and PPy: Cu nanoparticles were applied to the network. The fabricated networks were characterized using an X-ray diffractometer (XRD), UV-Vis. spectrometer, and Ato
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