Two dimensional meso-scale concrete modeling was used in finite element analysis of plain concrete beam subjected to bending. The plane stress 4-noded quadrilateral elements were utilized to model coarse aggregate, cement mortar. The effect of aggregate fraction distribution, and pores percent of the total area – resulting from air voids entrapped in concrete during placement on the behavior of plain concrete beam in flexural was detected. Aggregate size fractions were randomly distributed across the profile area of the beam. Extended Finite Element Method (XFEM) was employed to treat the discontinuities problems result from double phases of concrete and cracking that faced during the finite element analysis of concrete beam. Cracking was initiated at a small notch located at the middle of the bottom face of the concrete beam. The response of plain concrete beam subjected to pure bending via two point load application was detected using (XFEM) analysis of meso-scale concrete model. Assuming full bond between aggregate particles, and mortar at interfacial zone, the flexural strength of plain concrete beam is increased when aggregate particles size is increased, so that bending and shear stress were affected by void percentage and aggregate particles distribution. The maximum deflection at midspan was increased when the aggregate particles size decreases.
Insulin resistance is a fundamental feature of obesity, diabetes, and cardiovascular diseases and contributes to many of the metabolic syndrome's abnormalities. It is defined as a subnormal reaction to normal insulin concentrations or a situation in which greater than normal insulin concentrations are necessary for normal response.
A graphene-based supercapacitors (SC) were manufactured. The main objective of this research was to use as possible as environmentally, clean and natural materials for the SC electrodes, electrolytes and the separators. The SC consisted of a multi-layer graphene (MLG); as the electrode material, prepared by mixing graphene powder with water/acetone mixture, then the solution deposited on metal foils (aluminum and copper) by chemical spray technique, which is a simple and inexpensive technique to prepare the MLG films. The spraying time was (2 and 4 minutes) for making two MLG films with different thicknesses. The electrolytes were used is (lemon juice, table salt dissolved in water, and distillated water). The separators were a commercia
... Show MoreContinuous functions are novel concepts in topology. Many topologists contributed to the theory of continuous functions in topology. The present authors continued the study on continuous functions by utilizing the concept of gpα-closed sets in topology and introduced the concepts of weakly, subweakly and almost continuous functions. Further, the properties of these functions are established.
Background: The aim of this study was to evaluate and compare the static frictional forces produced by monocrystalline ceramic (sapphire) bracket and polycrystalline ceramic bracket. Materials and methods: one hindered twenty brackets/segment of archwire combinations were used, each bracket/segment of archwire combination was tested 10 times. The tests were performed in a universal testing Instron machine. The data was submitted to in depended t-test. Results: The independent sample t-tests showed a highly significant difference in the static frictional forces between monocrystalline ceramic (sapphire) bracket and polycrystalline ceramic bracket. Conclusion: According to the biomechanical result gained from the present study, the monocryst
... Show MoreIn this paper extensive examples and related counterexamples of the category of -skew -Armendariz rings are given. This category of rings regards a new generalization for the concepts of -skew Armendariz and skew -Armendariz rings. A ring is called -skew -Armendariz if for any ( ) Σ and ( ) Σ such that ( ) ( ) ( ), then ( ) ( ) for each and . First some general properties of -skew -Armendariz rings are studied and then relations between -skew -Armendariz rings and other related rings are investigated. Also various examples of non -skew -Armendariz rings are established.
Let R be a commutative ring with unity .M an R-Module. M is called coprime module (dual notion of prime module) if ann M =ann M/N for every proper submodule N of M In this paper we study coprime modules we give many basic properties of this concept. Also we give many characterization of it under certain of module.
Fao region is characterized by weak soft silty clay to clayey silt thick layer which extends to a depth of about 20 m. The construction of some structures on such soils may needs piles. During the installation of driven piles, the soil geotechnical properties are exposed to significant changes result due to shearing under large shear strains. These changes significantly decrease the shear strength of the virgin soil due to the destruction of soil structure caused by remolding. The degradation of shear strength is usually followed by strength regaining which is called “Thixotropy”. In this study, the thixotropic effect on Fao clay was investigated. Many disturbed and undisturbed soil samples were brought from Fao regi
... Show MoreIn contemporary discourses the debate of most Western thinkers is about the efforts to clarify the normative foundations of democracy. And then, some political thinkers have adopted other models differ in terms of standards for traditional liberal democracy. Be the common goal of democracy will give the formation of a greater role than usual in political liberalism rather than limiting the participatory activity of citizens on the function to give permanent legitimacy to the exercise of state authority. The activity is to be permanently enshrined in the democratic public sphere and the issue must be understood as the source of all political decisions.
Diyala Governorate was recently exposed to high flood waves discharged from Hemrin Dam. Since the dam was at its full capacity during the flood period, these waves were discharged to the Diyala River. Because of the reduction in Diyala River capacity to 750m3/s, the cities and villages on both sides of the river banks were inundated. Thus, the study's objective is to design a flood escape out of the Diyala River, to discharge the flood wave through it. The flood escape simulation was done by using HEC- RAS software. Two hundred twenty-three cross sections for the escape and 30 cross-sections of the Diyala River were used as geometric data. Depending on the geological formation that the escape passed t
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