Refractories are mineral and chemical-, based, materials with excellent heat resistance, making them ideal for use in the construction of ovens, furnace walls industries. According to this our research is concerned to study the effect of addition of (4% CaO) and (5% graphite) on the silica brick properties. Different amounts of CaO and Graphite were included in the white sand (raw ingredients) of silica bricks as a binder to prepare the composition then the composition were sintered using Different sintering temperatures ranging from (1000–1400)𝛐C under static air. Density, thermal conductivity, porosity, and water absorption Compression there was power tested after sintering. XRD analysis was used to identify raw materials’ physical, chemical, and mechanical qualities, as well as their mineralogical composition. Addition of Graphite to the firebrick mixture increased the challenges of getting good densification out of firebrick specimens with enhancement of the compressive, strength, bulk density especially at low firing temperatures since it increases formation of glassy phase as compared with 4%CaO, Addition of 4% CaO to silica brick the density of firebrick decreased, and the porosity and water absorption increased. Thermal conductivity of firebrick is decreased for 5% Graphite in comparison with 4% CaO to produce refractory silica brick with high quality of heat resistance, making them ideal for use in the construction of ovens, furnace walls industries.
Atotal of 551 water samples drinking( five Water Treatment Plans (WTPs) and raw water( from different sites on Tigris river) were collected.According to morphological characteristics and a set of biochemical tests, one hundred twenty eight of Aeromonas spp isolates were obtained In this study The percentages of Aeromonas recovery from river water was 72.52%, from wells water was (35%).Total percentage of positive aeromonas samples of treated water(Filtration &chlorine tank, supply water of WTPs, distribution system, reserviores and other samples not related to WPTs) was 8.8%.Count of Aeromonas in positive aeromonas samples ranging from 1 to 175 cfu 100 ml.
The results showed that generally no significant correlation between presen
In this research, we have measured specific activity concentrations in five samples for raw materials used in ceramic industry in AL-Ramadi ceramic factory by using (HPGe) detector. The results have shown that, the average specific activity, for 238U, 232Th and 40K are equal to (18.300±6.4 Bq/kg), (17.988±6.1 Bq/kg), (167.952±63.5 Bq/kg), respectively. In order to assess the radiological hazards of the radioactivity in samples, radium equivalent activity, absorbed gamma dose rate, indoor and outdoor annual effective dose rates, gamma Index and both (external and internal) hazard effects have been calculated. All results were found to be less than the allowed global limit given by (UNSCEAR, 2000).
... Show MoreThere are many problems facing the economic entities as a result of its mass production &variation of its products , the matter which had increased the need & importance of cost accounting which is regarded a main tool for the managerial control.
The actual costing system is unable to meet the contemporary management needs ,so the Standard costing system appear to provide the management with required information to perform its functions by the best use& way.
This research aims to determine the standard cost for the direct material for oil extraction activity by applying it in the north oil company.
The aim of this research is to study the surface alteration characteristics and surface morphology of the superhydrophobic/hydrophobic nanocomposite coatings prepared by an electrospinning method to coat various materials such as glass and metal. This is considered as a low cost method of fabrication for polymer solutions of Polystyrene (PS), Polymethylmethacrylate (PMMA) and Silicone Rubber (RTV). Si were prepared in various wt% of composition for each solutions. Contact angle measurement, surface tension, viscosity, roughness tests were calculated for all specimens. SEM showed the morphology of the surfaces after coated. PS and PMMA showed superhydrophobic properties for metal substrate, while Si showed hydroph
... Show MoreThe effect of SiO 2 ) Silica) on the dielectric and physical properties of Mnx-Ni1 -xFe2O4 ،، X=0.5 is studies. The samples are prepared by the conventional manufacturing
method. We found that the physical and dielectric properties of Mn-Ni ferrite change
considerably with the substituent samples .the variation of dielectric constant as a function of
frequency of ferrite system decrease with frequency increases and increase with the increase
the concentration of SiO 2 . It was found that the increase of SiO 2 concentration of all our
samples produce an increase in mass density and decrease with porosities
The microstructure and wear properties of 392 Al alloy with different Mg contents were studied using centrifugal casting. All melted alloys were heated to 800 ºC and poured into the preheated centrifugal casting mold (200-250 ºC) at different mould rotational speeds (1500, 1900 and 2300 r.p.m). It is clear from the results obtained that wear rate was dependent on the Mg content, applied load and mould rotational speed. Furthermore, wear test showed that the minimum wear rate was found in the inner layer of produced rings at mould rotational speed of 1900 r.p.m and Mg content of 5%.
Suggested in this study the introduction of monomers have the ability to interact with polyester Rzn way confused or Alchapak Vodev polycarbonate first Almiaal acrylate ????? grains and offered models for high temperature and for a period of time of 40 days and absorbance and penetration and after color changes resulting from the storage heat higher using shades where models were extractedthermal storage and take measurements and then returned periodically results were consistent with theoretical expectations and mixing
A total of 551 water samples (drinking and raw water) were collected In this study, Aeromonas.hydrophila, were detected by biochemical tests and PCR (16s rRNA gene). The results of identification showed that A.hydrophila had recovery rate 63 isolates (49.21%). The results revealed that all A.hydrophila isolates were PCR positive or the 16S rRNA gene and the results of sequencing showed that two isolates of A.hydrophila(local isolates) had percentage similarities 100% with A. hydrophila ATCC 7966 in GenBank database .All strains had a minimal Inhibitory Concentration(MIC) distribution pattern for lead cetate rranged (900-1200 μg/ml), and mercury chloride ranged (40-80 μg /ml).
This study involves the design of 24 mixtures of fiber reinforced magnetic reactive powder concrete containing nano silica. Tap water was used for 12 of these mixtures, while magnetic water was used for the others. The nano silica (NS) with ratios (1, 1.5, 2, 2.5 and 3) % by weight of cement, were used for all the mixtures. The results have shown that the mixture containing 2.5% NS gives the highest compressive strength at age 7 days. Many different other tests were carried out, the results have shown that the carbon fiber reinforced magnetic reactive powder concrete containing 2.5% NS (CFRMRPCCNS) had higher compressive strength, modulus of rupture, splitting tension, str
... Show More