The question about the existence of correlation between the parameters A and m of the Paris function is re-examined theoretically for brittle material such as alumina ceramic (Al2O3) with different grain size. Investigation about existence of the exponential function which fit a good approximation to the majority of experimental data of crack velocity versus stress intensity factor diagram. The rate theory of crack growth was applied for data of alumina ceramics samples in region I and making use of the values of the exponential function parameters the crack growth rate theory parameters were estimated.
Abstract
In this paper presents two dimensional turbulent flow of different nanofluids and ribs configuration in a circular tube have been numerically investigation using FLUENT 6.3.26. Two samples of CuO and, ZnO nanoparticles with 2% v/v concentration and 40 nm as nanoparticle diameter combined with trapezoidalribs with aspect ratio of p/d=5.72 in a constant tube surface heat flux were conducted for simulation. The results showed that heat flow as Nusselt number for all cases raises with Reynolds number and volume fraction of nanofluid, likewise the results also reveal that ZnO with volume fractions of 2% in trapezoidal ribs offered highest Nusselt number at Reynolds number of Re= 30000.
Key
... Show MoreEcological risk assessment of mercury contaminant has a means to analyze the ecological risk aspect of ecosystem using the potential impact of mercury pollution in soil, water and organism. The ecological risk assessment in a coastal area can be shown by mangrove zonation, clustering and interpolation of mercury accumulation. This research aims to analyze ecological risk assessment of potential mercury (including bioaccumulation and translocation) using indicators of species distribution, clustering, zonation and interpolation of mercury accumulation. The results showed that the Segara Anakan had a high risk of mercury pollution, using indicators like as the potential of mercury contaminant in water body was 0137±0.0137 ppm, substrate a
... Show MoreRadiation measuring devices need to process calibration which
lose their sensitivity and the extent of the response and the amount of
stability under a changing conditions from time to time and this
period depends on the nature and use of field in which used devices.
A comparison study was done to a (451P) (ionization chamber
survey meter) and this showed the variation of calibration factor in
five different years. This study also displayed the concept of
radiation instrument calibration and necessity of every year
calibration of them.
In this project we used the five years calibration data for ionization
chamber survey meter model Inspector (451P) to get that the values
of Calibration Factor (CF) and Res
Rivers Tigris and Euphrates, as well as the wetlands in southern Iraq and the Diyala River, were all included in the evaluation of earlier studies on the variety and factors impacting fish in Iraqi waters. Different studies documented different types, and the number of species recorded varied between the studies, which could be explained by the registration of some species, synonyms, differs from the registration of some species with synonymous names By mistake, as well as recording new species in times that followed some previous studies, Also, the difference in some factors, including the pollution of some waterways, leads to a difference in the existing species, so we find the presence of species that are tolerant of pollution. There are
... Show MoreThis paper studies the effect of mean wind velocity on tall building. Wind velocity, wind profile and wind pressure have been considered as a deterministic phenomenon. Wind velocity has been modelled as a half-sinusoidal wave. Three exposures have been studied B, C, and D. Wind pressure was evaluated by equation that joined wind pressure with mean wind velocity, air density, and drag coefficient.
Variations of dynamic load factor for building tip displacement and building base shear were studied for different building heights, different mode shapes, different terrain exposures, and different aspect ratios of building plan. SAP software, has been used in modelling and dynamic analysis for all case studies.
... Show MoreThis Book is intended to be a textbook studied for undergraduate course in financial statistics/ department of Financial Sciences and Banking. This book is designed to be used in semester system. To achieve the goals of the book, it is divided into the following chapters. Chapter one introduces basic concepts. Chapter two devotes to frequency distribution and data representation. Chapter three discusses central tendency measures (all types of means, mode, and median). Chapter four deals with dispersion Measures (standard deviation, variance, and coefficient of variation). Chapter five concerned with correlation and regression analysis. While chapter six concerned with testing Hypotheses (One population mean test, Two "independent" populati
... Show MoreThe drive of this exploration is to investigate the mucoadhesive assets of A. indica (Azadirachta indica) fruit mucilage by incorporating it into mucoadhesive microspheres with Acyclovir (AVR) as a model drug. The study was performed to check the impact of the mucilage proportion on particle size and swelling index. Nine batches of AVR mucoadhesive microspheres were made with varying proportions of Polyacrylic acid 934P and A. indica fruit mucilage (AIFM). A central composite design with design expert software to check the impact of dependent variables (A. indica mucilage and Polyacrylic acid 934 P levels) on particle size and swelling index as a response. As part of congeniality studies, the batches w
... Show MoreBackground: Thalassemia is characterized by the decrease or absence of the synthesis of one or more globin chains of hemoglobin. Thalassemia is distributed worldwide and is characterized by; regular blood transfusion which is creating alloimmunization to erythrocyte antigens is one of the major complications of regular blood transfusions in thalassemia, particularly in patients who are chronically transfused.Objectives: The aims of this study are to understand the immune system profile as the triggering factor for thalassemia.Methods: Thirty patients aging between one year and four months and twenty two years, twenty two of them were boys and eight were girls. Twenty nine patients, their parents are relative except one and studied in the
... Show MoreThe dimensions of bubbles were measured in a stirrer tank electrochemical reactor, where the analysis of the bubble size distribution has a substantial impact on the flow dynamics. The high-speed camera and image processing methods were used to obtain a reliable photo. The influence of varied air flow rates (0.3; 0.5; 1 l/min) on BSD was thoroughly investigated. Two types of distributors (cubic and circular) were examined, and the impact of various airflow rates on BSD was investigated in detail. The results showed that the bubbles for the two distributors were between 0.5 and 4.5 mm. For both distributors at each airflow, the Sauter mean diameter for the bubbles was calculated. According to the results, as the flow rate raised, the bubb
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