Phase change materials are known to be good in use in latent heat thermal energy storage (LHTES) systems, but one of their drawbacks is the slow melting and solidification processes. So that, in this work, enhancing heat transfer of phase change material is studied experimentally for in charging and discharging processes by the addition of high thermal conductive material such as copper in the form of brushes, which were added in both PCM and air sides. The additions of brushes have been carried out with different void fractions (97%, 94% and 90%) and the effect of four different air velocities was tested. The results indicate that the minimum brush void fraction gave the maximum heat transfer in PCM and reduced the time
... Show MoreAbstract: Iatrogenic furcal root perforations are serious complications during dental treatment. This study was aimed to compare the sealing ability of new bioceramic root repair material TotalFill® with the other perforation repair materials (GIC, MTA and Biodentine) using a dye- extraction method.Materials and Methods: Forty extracted, human mandibular molars with non-fused well developed root were collected. Artificial perforations were made from the external surface of the teeth. Then the teeth were randomly divided into 4 experimental groups (n= 10) according to the type of repair material used in this study; Medifil glass ionomercement, TotalFill® bioceramic root repair material, BiodentineTM and MTA Plus. The specimens were then im
... Show MoreThe present work aimed to study effect of (N749 & N3) dyes on TiO2 optical and electrical properties for optoelectronic application. The TiO2 paste prepared by using a doctor blade method. The samples were UV-VIS specterophometricall analyzes of TiO2 before and after immersed in dyes (N749 & N3). The results showed absorption spectra shift toward the visible region due to the adsorption of dye molecules on the surface of oxide nanoparticles. It is seen that the Eg determined to give a value of 3.3eV for TiO2 before immersing in dyes, and immersing in dyes (N749 & N3) are (1.4 &1.6 eV) respectively. The structural properties (XRD), (FTIR) and (SEM) for the sample prepared were investigated and (J-V) characteristics was stu
... Show MoreThe arise of Islam as a multidimensional changing phenomenon with its own revolutionary and comprehensive character was inherent with a lot of alterations in social aspects , and this is explicit particularly in the scope of urban life and town planning . Essentially, Islamic style of life has its own urban identity. The urbanization process in Islam has been developed across two integrated sides, the first one concerned on ideational and theoretical aspects , while the other associated with practice .Many urban centers emerged during the Islamic era since the erection of Basrah , the first Islamic town in the middle of the 7th. centaury. Some contemporary urban concepts , both environmental and social could be noticed in Islamic
... Show MoreConcentrations of uranium were measured in this study for twenty soil samples from four areas with different depths (soil surface-20-40-60-80)cm .The study regions include Missan Governorate (Al-Iskan area,Al-Shibbana area ,Hai-Al Moualimin Al Jadied area ,Sector 30 area). The Uranium concentrations in soil samples measured by using fission tracks registration in (CR-39) track detector that caused by the bombardment of (U-283) with thermal neutrons from (241Am-Be) neutron source that has flux neutron thermal of (5 ×103 n cm-2 s-1). The concentrations values were calculated by a comparison with standard samples. Through out the result, it was found that averages of uranium concentrations in soil samples were as the following : Al - Iskan
... Show Morestudy was conducted on a stretch of Tigris river crossing Baghdad city to determine the concentration of some chlorophenols pollutants. Aqueous samples were preliminary enriched about 500 times and the chlorophenols have determined using high performance liquid chromatography HPLC. Limits of detection LOD were (0.007–0.012 mg L-1), relative standard deviations RSD% were 2.4%–5.59% and relative recoveries were 51.06%– 104.07%. The existence of chlorophenols in Tigris river was in the range 0.023–4.596 mg L-1. The developed method suggested in this study can be applied for routine analysis and monitoring of chlorinated phenols in environmental aqueous samples.
Trickle irrigation is one of the most conservative irrigation techniques since it implies supplying water directly on the soil through emitters. Emitters dissipate energy of water at the end of the trickle irrigation system and provide water at emission points. The area wetted by an emitter depends upon the discharge of emitter, soil texture, initial soil water content, and soil permeability. The objectives of this research were to predict water distribution profiles through different soils for different conditions and quantify the distribution profiles in terms of main characteristics of soil and emitter. The wetting patterns were simulated at the end of each hour for a total time of application of 12 hrs, emitter disch
... Show MoreOne of the most important problems in concrete production in Iraq and other country is the high sulfate content in sand that led to damage of concrete and hence reduces its compressive strength and may leads to cracking due to internal sulfate attack and delay ettringite formation. The magnetic water treatment process is adopted in this study. Many samples with different SO3 content are treated with magnetic water (12, 8, 4 and 2)L that needed for each 1kg of sand with the magnetic intensity (9000 and 5000) Gaus. The magnetic water needed is reduced with less SO3 content in sand. The ACI 211.1-91 concrete mix design was used in this research with slump range (75- 100) mm and the specified compressive strength (35MPa). The compressive streng
... Show MoreThe shortage of irrigation water requires specific measures. One of these measures is the application of the rationing system (a period of irrigation followed by a period of drought). This system could have an effect on the behavior and properties of irrigation canals. So, studying rationing system on the irrigation canals is important both in civil engineering and water resources engineering, especially if these channels constructed with gypsum soil. This study includes the calculation of seepage velocity and water content in each cycle (10 days wetting and 10 days of drying). The model is built for this research contains four samples, two samples for untreated soil one of them expos
The aquatic crude extract of Silybum marianum dry grains prepared by melting them in distil water by the method of soak and shake. The effect of Silybum marianum crude extract studied in vitro on three tumor cell line the Hep-2, AMN-3 and RD for 24, 48 and 72 hours of exposure, and one cell line of normal cells REF for 72 hr exposure. The results showed that the prescence of toxic effect of the aquatic crude extract on the cell lines of Hep-2, AMN-3 and RD at 10 and 100 µg/ ml upto the higher concentrations when they exposed to the extract for 48 hr. as compared with the control treatment, and when the exposure period increased to 72 hr. the toxic effect started at low concentrations (5 and 10 µg/ ml) as compared with the control g
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