In this paper we present the theoretical foundation of forward error analysis of numerical algorithms under;• Approximations in "built-in" functions.• Rounding errors in arithmetic floating-point operations.• Perturbations of data.The error analysis is based on linearization method. The fundamental tools of the forward error analysis are system of linear absolute and relative a prior and a posteriori error equations and associated condition numbers constituting optimal of possible cumulative round – off errors. The condition numbers enable simple general, quantitative bounds definitions of numerical stability. The theoretical results have been applied a Gaussian elimination, and have proved to be very effective means of both a priori and a posteriori error analysis.
Sand dunes are spread in multiple places in the world especially in a desert area as a result of economic development and construction processes, there was a need to study the behavior of sand dunes and make it suitable for construction. This paper aims to study the effect of adding sodium silicate on the cohesion strength of sand dune and its behavior. The results show that the cohesion strength increase as a percentage of sodium silicate increase (addition 8% Sodium silicate show the higher cohesion) and the cohesion between sand dune particles increase excepted when using 10% sodium silicate the cohesion began to decrease. However, the effect of curing time is significant and shows
Recently, interest in the use of projectiles in research on recycling waste materials for construction applications has grown. Using recycled materials for the construction of asphalt concrete pavement, in the meantime, has become a topic of research due to its significant benefits, such as cost savings and reduced environmental impacts. This study reports on comprehensive experimental research conducted using a typical mechanical milling waste, iron filing waste (IFW), as an alternative fine aggregate for warm mix asphalt (WMA) for pavement wearing surface applications. A type of IFW from a local machine workshop was used to replace the conventional fine aggregate, fine natural sand (FNS), at percentages of 25%, 50% 75%, and 100% b
... Show MoreDespite widespread agreement on the beneficial nature of hydrated lime (HL) addition to asphalt concrete mixes, understanding of the effect of HL particle size is still limited. Previous investigations have focused mainly on two different size comparisons, and so certain guidance for a practical application cannot yet be produced. This study investigates three distinct sizes of HL, in the range of regular, nano, and sub-nano scales, for their effects on the properties of modified asphalt concretes. Five different percentages of HL as a partial replacement of ordinary limestone filler in asphalt concrete mixes were studied for wearing course application purposes. Experimental tests were conducted to evaluate the mechanical properties
... Show MoreA hand lay-up method was used to prepare Epoxy/ metal composites. Epoxy resin (EP) was used as a matrix with metal particles (Al, Cu, and Fe) as fillers.
The preparation method includes preparing square panels of composites with different weight percentage of fillers (10, 20, 30, 40, and 50%). Standard specimens (88mm in diameter) for thermal conductivity tests were prepared to measure thermal conductivity kexp.The result of experimental thermal conductivity kexp, for EP/metal composites show that, kexp increase with increasing weight percentage, For EP/ Al and EP/Cu composites, and it have have maximum values of 0.33 and 0.35 W/m.K, respectively. While kexp for EP/ Fe composite show slight increase with maximum value of 0.186 W/m.K.
EP/ metal composites were prepared as adhesives between two steel rods. Epoxy resin (EP) was used as a matrix with metal as fillers (Al, Cu, Fe,).
The preparation method for tensile adhesion tests includes two steel rods with adhesive composites between the rods to measure adhesion strength Sad and adhesion toughness Gad.
Results of tensile adhesion tests show that EP/ metals composite have maximum strength Sad for certain weight percentage of metals 2.95 and 9MPa at 10% for EP/Al and EP/Cu composite and 8.2MPa at 40% for EP/Fe composites
The aqueous extract of Citrullius colocynthis dried seeds (160 ?g/ml) was in vitro evaluated for its effect on phagocytic index (PI) and lymphocyte transformation index (LTI) of blood cells obtained from 30 apparently healthy blood donors (15 males and 15 females). The PI was further in vivo evaluated in cells of peritone, spleen and liver of mice treated with the extract at a dose of 0.64 mg/kg. The results revealed that in in vitro study, phagocytic cells treated with the extract showed a significant increased percentage as compared with untreated cells (60.0 vs. 44.1%). Phagocytes obtained from peritone (44.1 vs. 30.0%) and spleen (45.6 vs. 39.6 %) of treated and untreated mice behaved in a similar manner, while liver phagocytes showed n
... Show MoreIn this study, dependence of gamma-ray absorption coefficient on the size of Pb particle size ranging from 200µm up to 2.5mm, using different weights of each particle size. The results show that gamma-ray attenuation coefficient is inversely proportional with the size of Pb particle size due to the reduction of the spaces between the lead particles.
Accompanied Activity Economic Unity some negative effects in the environment of air, water and soil pollution of difficult to measure each other for being the external costs and to be avoided such expenditures should be measured or estimated value to be disclosed environmental costs at the heart of the financial statements of economic unity to inform managers and users of the financial statements on the implications costs environmental .and impact in reducing environmental costs and increase future income and economic unit, was based on research into the inductive approach through books, letters, journals and the internet to cover the theoretical framework of the research. And to the analyt
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