Free cement refractory concrete is a type of refractory concrete with replacing alumina cement by bonding materials such as white kaolin, red kaolin and fumed silica. The free cement refractory concrete used in many applications like Petrochemicals, iron furnaces and cement production industries. The research clarifies the effect of steel fibers with two types crimped steel fibers and hooked steel
fibers with percentages 0.5%, 1% and 1.5% by volume from weight of bauxite aggregates. The additions of steel fibers with two types gave good properties in high temperatures where the specimens keep the dimension without failure and the properties made the best. the percentage of increasing for thermal conductivity was 44% for 1.5% crimped fibers and 42.8% for 1.5% hooked end fibers and the percentage increasing in bulk density of free cement refractory concrete was 30% for 1.5% crimped fibers and 27% for 15% hooked end fibers . From this study can be concluded that the best types of steel fibers which used in free cement refractory concrete is the crimped type with percentage 1.5%.
It is shown that pure and 3% boron doped a-Si0.1Ge0.9:H and a-Si0.1Ge0.9:N thin films
could be prepared by flash evaporation processes. The hydrogenation and nitrogenation
are very successful in situ after depositing the films. The FT-IR analysis gave all the
known absorbing bonds of hydrogen and nitrogen with Si and Ge.
Our data showed a considerable effect of annealing temperature on the structural and
optical properties of the prepared films. The optical energy gap (Eopt.) of a-Si0.1Ge0.9
samples showed to have significant increase with annealing temperature (Ta) also the
refractive index and the real part of dielectric constant increases with Ta, however the
extinction coefficient and imaginary part of dielect
In this investigation, metal matrix composites (MMCs) were manufactured by using powder technology. Aluminum 6061 is reinforced with two different ceramics particles (SiC and B4C) with different volume fractions as (3, 6, 9 and 12 wt. %). The most important applications of particulate reinforcement of aluminum matrix are: Pistons, Connecting rods etc. The specimens were prepared by using aluminum powder with 150 µm in particle size and SiC, B4C powder with 200 µm in particle size. The chosen powders were mixed by using planetary mixing setup at 250 rpm for 4hr.with zinc stearate as an activator material in steel ball milling. After mixing process the powders were compacted by hydraulic
... Show Moreresearch aim :
- The research aimed to investigate the effect of two treatment
methods in the gaining of fourth grade students in geography
object.
- Research hypothesis
there are no statistically significant differences at the level of ( 0.05 )
in the average level of achievement in geography between the first
experimental group ( strengthening lessons ) and the second group
( re- teaching )
no individual differences statically significant at the level of ( 0.05 )
in the average level achievement in geography object of the second
experimental group ( re- teaching ) and the first experimental group
( strengthening lesson )
the research sample : the researcher selected randomly Baghdad
The present study was conducted to determine histopathological changes caused by chronic effect of Nitrofurantoin(NFT) in The albino mice Testes. The Study included 40 mice were divided on the five groups: the first group taken distilled water and become control group . the remaining group which are exposure with NFT drug in concentration (100-150-200-250) mg / kg, respectively, Doses were given orally for a period (month and two months). The results of histopathological changes included occurrence of congestion in the blood vessel and degeneration of spermatogonia and aggregation of spermatids in the lumen of semineferous tubules and inhibition of spermatogensis process and decrease of sperm inside the lumen
... Show MoreThe types of traditional houses vary from region to region according to physical and non-physical circumstances, and Sulaymaniyah city is characterized by a type of traditional houses that differ significantly from those in most cities and regions neighboring are always different from the general pattern that is prevalent in the region and the Muslim world.
The aim of this research is to study the cause of this difference or distinction in the traditional houses in Sulaimaniyah city, by comparing the most common models in these houses and comparing them with the general models of village houses that originally existed in the region to relaize the convergence and contrast between them. The research was based on a co
... Show MoreThe objective of the research , is to shed light on the most important treatment of the problem of missing values of time series data and its influence in simple linear regression. This research deals with the effect of the missing values in independent variable only. This was carried out by proposing missing value from time series data which is complete originally and testing the influence of the missing value on simple regression analysis of data of an experiment related with the effect of the quantity of consumed ration on broilers weight for 15 weeks. The results showed that the missing value had not a significant effect as the estimated model after missing value was consistent and significant statistically. The results also
... Show MoreObjective: This research was carried out in rats in a special place of the laboratory of histopathological diseases in the period 6/9/2018 until 23/11/2018, this study to detect effect of the addition of the alcohol extract of ginger in the reduction of fat in liver tissue of rats. Method: Eight groups and replicates for each group. The groups were homogenous in weights and were placed in 13 cages. Each group consisted of 10 rat and at 5 fares each. In the first treatment, rat were fed on regular feeding without adding and feeding rats in the second treatment sessions add to it the alcoholic extract of ginger in Turkey 150 mg/kg. The third group is the same as the normal food after adding the alcohol extract of ginger at a concentration of
... Show MoreThe research aims to explain the role of cloud computing technology in facilitating the application of international financial reporting standards in Iraqi banks, by preparing a checklist that included a set of paragraphs to measure the level of application of IFRSs. In those banks and then the need to use cloud computing technology, and the researchers reached a set of conclusions, including, that cloud computing technology has a role in facilitating the application of international financial reporting standards in the banks, the research sample, because of the ease it provides in preparing and saving accounting information and the possibility of accessing it in any time and from any place where the Internet service is available. T
... Show More