The primary purpose of the present research was to study the effect of polyvinyl chloride (PVC) powder content on ultrasonic wave velocity in PVC/Epoxy composites. The second part is concerned with the relations of dynamic elastic moduli with the ultrasonic wave velocities, to determine how ultrasonic waves can affect them.
Experimental data have been obtained using the sonic viewer (model -5217 A) device to generate two types of waves, longitudinal waves of frequency 63 kHz and transverse waves of frequency 33 kHz and to measure the transit time required for those waves to travel through individual sample.
The experimental results have shown that the propagation of the ultrasonic velocity increases directly with PVC content in the tested specimens, due to the changes in the dynamical properties that were investigated from the calculated values of the elastic moduli of the composites
Receipt date:3/13/2021 accepted date:5/26/2021 Publication date:12/31/2021
This work is licensed under a Creative Commons Attribution 4.0 International License.
energy is one of the strategic resources within international politics, and this is through the existing competition between the international powers on it, and the global powers have begun to rely on interest in new areas, such as import, depending on new projects an
... Show MoreThe materials of soil were affected by multi reasons; such as human activities, floods, tidal waves, ... etc. The change of the soil contents could be measured through different indexes; such as electric conductivities, salinity, concentration of the heavy elements, and concentration of essential elements ... etc. The land cover is affected by natural influences, like tidal energy, which plays a negative role in the salinization of land adjacent to the coasts, causing a problem for soils in all its details represented in changing of the dissolved elements in soil. One of the most important natural factors that cause soil salinity is human activity in all its forms, and one of the most important causes of salinity is the phenomenon o
... Show MoreRoller compacted concrete (RCC) is a special type of concrete with zero or even negative slump consistency. In this work, it had aimed to produce an RCC mix suitable for roads paving with minimum cost and better engineering properties so, different RCC mixes had prepared i.e. (M1, M2, M3, and M4) using specified percentages of micro natural silica sand powder (SSP) as partial replacement of (0%, 5%, 10%, and 20%) by weight of sulfate resistant Portland cement. Additionally, M-sand, crushed stone, filler, and water had been used. The results had obtained after 28 days of water curing. The control mix (M1) had satisfied the required
Castellated columns are structural members that are created by breaking a rolled column along the center-line by flame after that rejoining the equivalent halves by welding such that for better structural strength against axial loading, the total column depth is increased by around 50 percent. The implementation of these institutional members will also contribute to significant economies of material value. The main objectives of this study are to study the enhancement of the load-carrying capacity of castellated columns with encasement of the columns by Reactive Powder Concrete (RPC) and lacing reinforcement, and serviceability of the confined castellated columns. The Castellated columns with RPC and Lacing Reinforcement improve com
... Show MoreIn this work, we studied the effect of power variation on inductively coupled plasma parameters using numerical simulation. Different values were used for input power (750 W-1500 W), gas temperature 300K, gas pressure (0.02torr), 5 tourns of the copper coil and the plasma was produced at radio frequency (RF) 13.56 MHZ on the coil above the quartz chamber. For the previous purpose, a computer simulation in two dimensions axisymmetric, based on finite element method, was implemented for argon plasma. Based on the results we were able to obtain plasma with a higher density, which was represented by obtaining the plasma parameters (electron density, electric potential, total power, number density of argon ions, el
... Show MoreChronic renal failure (CRF) affects thyroid function in multiple ways, including low circulating thyroid hormone concentration, altered peripheral hormone metabolism, disturbed binding to carrier proteins, possible reduction in tissue thyroid hormone content, and increased iodine store in thyroid glands.The target of study is to find a relationship between chronic renal failure and thyroid function.In addition, we tried to study the effect of CRF on serum creatinine dependent on the level of thyroid hormones (T3 and T4) and thyroid stimulating hormones(TSH). Forty patients with chronic renal failure (20 male, 20 female) were enrolled in this study in addition to forty healthy individual as control gro
... Show MoreThe activation energy and optical band gap of different regions (p-type) polysilicon have been measured. Both microscopic studies and current-voltage characteristics of diodes prepared on different surface regions were carried out. Comparison of diodes parameters and microscopic studies indicate that the type of angles between boundaries has a significant effect on diodes parameters while the boundary lengths per unit area has less effect. The mechanism of Al-interaction with grain boundaries and their intersecting points at different temperature were also studies. The X-ray fluorescence spectrometry has been used for detection of diffused A1%.
Aim: This study aimed to compare different types of ligation methods to obtain maximum tooth movement with the least undesirable rotation. Methods: Titanium brackets bonded to acrylic canine teeth were ligated to straight stainless steel (SS) archwires using four ligation methods (figure-O and figure-8 elastics, SS ligatures, and Leone Slide ligatures). The teeth with the ligatures in place were stored in a water bath at 37ºC for 1 day, 1 week, 2, 4 or 6 weeks before testing. The teeth were retracted through softened wax along the archwire and the amount of tooth movement and degree of rotation were measured. Results: Slide ligatures showed the highest distance of tooth movement and degree of canine rotation followed by figure-O elastics
... Show MoreThe aim of this paper is to determine the effect of internal marketing through three dimensions: vision, development, and reward - on organizational citizenship behavior in three private universities in Iraq. Organizations’ view of their members as internal customers could be made them more realistic in dealing with the reasons for leaving and going to other organizations. This can promote business organizations to build an organizational environment that contributes to making the organization look like the homeland of those workers. The research method is descriptive and analytical. The tool for data collection was the questionnaire. Statistical software (SPSS V.23 and AMOS V.23) was used to analyze the data. The research sample was r
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