The varied thermal conductivity (insulation) of silica aerogel with heating for different pH has been investigated, it has been depended on ambient pressure drying method in the preparing silica aerogel samples, also six different pH of samples (1, 2, 3, 7, 8 and 9) were treated under five degree of heating with (50,100,150,200 and 250) ᴼC. This technique is important to test the carry-outs hydrophobic silica to temperature without high-quality material changes in the basic characteristics. The hot-wire technique is used in this work to examine the thermal conductivity, Fourier Transform Infrared Spectroscopy (FTIR) depended to characterize the bonds and their artificial by heating. Results show that the samples affected by heating through decreasing the density leading to obtaining more insulation metal, moreover varied pH is an important role in thermal conductivity. The average thermal conductivity of all aerogel samples in this work is (0.01- 0.0061 mW m-10 C-1) this means that it is still below thermal conductivity for air equals to (0.02257) mW m-10 C-1 . Meanwhile, we concluded that the insulation property of silica aerogel is affected by heat treatment and gives it more thermal insulation property.
Student performance may influence by several factors in all his study levels such as primary school, intermediate school and even in his college; some of these factors are psychological factors, social factors, and the factors which correlate with student environment.
In this paper we study some of these factors to discover their influence by using canonical correlation analysis to analyze the data. Many conclusions are discovered to help who focuses student performance or to make it pest in future.
Transformations of the actor when acting many characters are the product of joint work between the actor and the director through the instructions and the exercises that facilitate the reach for the desired goal.
The method or way has often been used which is Stanislavsky premises in his work with the actor in the role. The first section consists of two parts under the heading of the actor's work with himself. The two parts are preparing the actor in creative suffering (internal), and in coexistence and embodiment (outside). The second section is the book of the actor's work with the role. The current research aims at identifying the mechanism of the acting performance transformations among many characters of the same actor.
... Show MoreMultiple linear regressions are concerned with studying and analyzing the relationship between the dependent variable and a set of explanatory variables. From this relationship the values of variables are predicted. In this paper the multiple linear regression model and three covariates were studied in the presence of the problem of auto-correlation of errors when the random error distributed the distribution of exponential. Three methods were compared (general least squares, M robust, and Laplace robust method). We have employed the simulation studies and calculated the statistical standard mean squares error with sample sizes (15, 30, 60, 100). Further we applied the best method on the real experiment data representing the varieties of
... Show MoreThe present work aims to study the combustion characteristics related to syngas-diesel dual-fuel engine operates at lambda value of 1.6 operated by five different replacement ratios (RR) of syngas with diesel, which are (10%, 20%, 30 %, 40 % and 50%). ANSYS Workbench (CFD) was used for simulating the combustion of the syngas-diesel dual-fuel engine. The numerical simulations were carried out on the Ricardo-Hydra diesel engine. The simulation results revealed that the diesel engine’s combustion efficiency was enhanced by increasing the diesel replacement with Syngas fuel. The diesel engine’s combustion efficiency The peak in-cylinder temperature was enhanced from 915.9K to 2790.5K
Abstract-Industrial and urban development has resulted in the spread of plastic waste and the increase in the emissions of carbon dioxide resulting from the cement manufacturing process. The current research aims to produce green (environmentally friendly) concrete by using plastic waste as coarse aggregates in different proportions (10% and 20%) and nano silica sand powder as an alternative to cement in different proportions (5% and 10% by weight). The results showed that compressive strength decreased by 12.10% and 19.23% for 10% and 20% plastic waste replacement and increased by 12.89% and 20.39% for 5% and 10% silica sand replacement respectively at 28 days. Flexural strength decreased by 12.95% and 19.64% for 10% and 20% plastic waste
... Show MorePure Polyaniline salt, and protonation PANI by H2SO4 were synthesized by electro-chemical oxidative polymerization of aniline with acidity of H2SO4. The solution was prepared in reaction temperature equal 291 K and the acidity of aqueous solution was 1 molarities. The prepared polyaniline was characterized by FT-IR, the result indicate that the intensity is increase with increasing of applied voltage. The dc conductivity has been measured for bulk polyaniline pure and doped in the form of compressed pellet with evaporated Ohmic Al electrodes in temperature range (303-423) K. The Eav energy of the thermal rate process of the electrical conductivity was determined. The results indicate that the dc conductivity of doped samples are two or t
... Show MoreThe implementation of nanotechnology in all industries is one of most significant research fields. Nanoparticles have shown a promising application in subsurface fields. On the other hand, various surfactants have been used in the oil industry to reduce oil/water interfacial tension and also widely used to stabilize the nano-suspensions. The primary objective of this study was to investigate the improvements of surfactants ability in term of interfacial tension (γ) reduction utilizing addition of silicon dioxide nanoparticles at different temperatures and salinity. The pendant drop technique has been used to measure γ and electrical conductivity has been used to measure the critical micelle concentration (CMC). The synergistic effects of
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