TEOS aerogel a is the most commonly used. a Aerogel has attracted increasing attention from both academic and industries due to its extraordinary performance and potentials. We have systematically studied the relationship between the densification temperature of the synthesis environment of silica aerogels on their resulting morphological, optical and thermal properties. SEM and BET measurements were employed as structural probes to ascertain the structural differences. Lee's disc apparatus was used for determining the thermal conductivity coefficient. There is a systematic correlation between the annealing temperature and the aerogel surface area, porosity, as well as pore size. The implemented autoclave was able to produce aerogel monolith of surface area reaching to 998.25 g/m2 and low electric conductivity arrive to of 1.17*10-4(s/m), associated with density of 0.047 g/cm3.The calculated thermal conductivities were (0.0063, 0.016 and 0.0053 mW m-1 0 C-1) for pH1, pH7 and pH8 samples respectively. The microstructure observed is categorized into three types, namely, open cellular foam (the substance that is formed by trapping pockets of gas in solid), fractal (the structural features it's clearly show the hierarchical repetition) and isotropic morphology (visible spectrum scale). The aerogel properties were are remarkably varied. While the influence of annealing temperature the reaction setting has gradually influence on the final aerogel properties, h However, it is obviously requested for achieving desirable optically and nano-featured products.
A high Tc superconductor with a nominal composition
(Bi1-xPbx)2(Sr1-yBay)2Ca2Cu3O10+δ for (0 £ x £ 0.5) and (0 £ y £ 0.5) was prepared by
a solid state reaction method. The effect of the substitution of Pb for Bi and Ba for Sr and
quenching temperature on the superconductivity has been investigated to obtain the
optimum conditions for the formation and stabilization of the high Tc phase (2223).
The results showed that the optimum sintering temperature for the pure composition is
equal to 875°C and the sintering time is equal to 240h with heating and cooling rate of
60°C/h . Our results indicated that a small amount of (Ba = 0.1) could raise the transition
temperature (Tc), but enhancing Ba to 0.4 has raised
Medicinal plants are used to treat various diseases although little is known about their toxicity. Coriandrum sativum is one of the most commonly plants that is used to treat several physiological disorders. Thus, this study was conducted to evaluate the effect of aqueous extract of C. sativum on the structure and function of liver in male albino mice. Thirty male mice were randomly divided into three groups: Group 1 untreated (control), Group 2 and 3 were administrated orally with the aqueous extract of the plant at dose 125 and 250 mg/kg. b. w. For 30 days. The effect of the extract on liver weights, biochemical parameters as well as histological study were assessed. There were no significant difference (P>0.05) observed in relative organ
... Show MoreMedicinal plants are used to treat various diseases although little is known about their toxicity. Coriandrum sativum is one of the most commonly plants that is used to treat several physiological disorders. Thus, this study was conducted to evaluate the effect of aqueous extract of C. sativum on the structure and function of liver in male albino mice. Thirty male mice were randomly divided into three groups: Group 1 untreated (control), Group 2 and 3 were administrated orally with the aqueous extract of the plant at dose 125 and 250 mg/kg. b. w. For 30 days. The effect of the extract on liver weights, biochemical parameters as well as histological study were assessed. There were no significant difference (P>0.05) observed in relative
... Show MoreBackground: The effect of garlic extracton fungal
growth and keratinolytic activity was studied in
Trichophytonmentagrophytes as one of the major
etiologic agents of human and animal dermatophytosis
in Baghdad and other parts of the World.
Objective: To investigated an alternative
antidermatophyte with minimum side effects which is
plant based and biodegradable natural product
Methods: Culture conditions for 30 isolates of T.
mentagrophytes isolated from human dermatophytosis
from both sexes with ages of 5-63 years in Central
Medical city for the period July 2009 to October 2009
were cultured on specific solid medium.
Results: The aqueous extract of garlic at various
concentrations inhibited the
Abstract
This study came to clarify the redemption in terms of being a method and a subject of knowledge that has its causes, controls, etiquette and scientific implications for Muslim scholars.
The science of redemption has a historical extension, starting from the era of the Companions - may God be pleased with them - and through the stages of codification and classification of works in an effort to document it and diversify its methods at the inductive, analytical, critical and argumentative levels, and to determine its causes and from the completion of the research conclude it with evidence of its scientific effects because it is a science that enriched the Islamic library in general, and hadith in particular.
This paper is focused on studying the effect of cutting parameters (spindle speed, feed and depth of cut) on the response (temperature and tool life) during turning process. The inserts used in this study are carbide inserts coated with TiAlN (Titanum, Aluminium and Nitride) for machining a shaft of stainless steel 316L. Finite difference method was used to find the temperature distribution. The experimental results were done using infrared camera while the simulation process was performed using Matlab software package. The results showed that the maximum difference between the experimental and simulation results was equal to 19.3 , so, a good agreement between the experimental and simulation results was achieved. Tool life w
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Discrete Krawtchouk polynomials are widely utilized in different fields for their remarkable characteristics, specifically, the localization property. Discrete orthogonal moments are utilized as a feature descriptor for images and video frames in computer vision applications. In this paper, we present a new method for computing discrete Krawtchouk polynomial coefficients swiftly and efficiently. The presented method proposes a new initial value that does not tend to be zero as the polynomial size increases. In addition, a combination of the existing recurrence relations is presented which are in the n- and x-directions. The utilized recurrence relations are developed to reduce the computational cost. The proposed method computes app
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In the present study, we have reported investigations on the effect of simultaneous substitution of Tl at the Hg site in the oxygen deficient HgOδ layer of Hg1-xTlxBa2Ca2Cu3O8+ δ cuprate superconductor. Bulk polycrystalline samples were prepared by the two-step solid state reaction process. It was observed that the grown Hg1-xTlxBa2Ca2Cu3O8+ δ corresponds to the 1223 phase. Electrical resistivity, using four probe technique, is used to find the transition temperature Tc. The highest Tc(0ffset) were 108, 102,113, 118, 125 and 121K for Hg1xTlxBa2Ca2Cu3O8+ δ with x = 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25 respectively. The optimum Tc(off) of ~ 125 K and Tc(onset) ~ 136K was fo
... Show MoreThe determination of critical micelle concentration of selected non-ionic surfactants (Tween 20,40 and 80) have been investigated using magnetic water(MW)as an aqueous medium.Conductometry technique is used to determine critical micelle concentration.The effect of alcohol addition and temperature variation at the range(293.15 -303.15K) are also pursued. It is concluded that the process of micellization is spontaneous and endothermic because of the observed free energy of micellization (ΔGom) , enthalpy change of micellization (ΔHom), and entropy change of micellization (ΔSom) for the system was also studied.The properties of the non-ionic surfactants were studied, both in absence and presence of
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