The enhancement of heat exchanger performance was investigated using dimpled tubes tested at different Reynolds numbers, in the present work four types of dimpled tubes with a specified configuration manufactured, tested and then compared performance with the smooth tube and other passive techniques performance. Two dimpled arrangements along the tube were investigated, these are inline and staggered at constant pitch ratio X/d=4, the test results showed that Nusselts number (heat transfer) of the staggered array is higher than the inline array by 13%. The effect of different depths of the dimple (14.5 mm and 18.5 mm) has been also investigated; a tube with large dimple diameter enhanced the Nusselts number by about 25% for the ran
... Show MoreSoil stabilization with stone powder is a good solution for the construction of subgrade for road way and railway lines, especially under the platforms and mostly in transition zones between embankments and rigid structures, where the mechanical properties of supporting soils are very influential. Stone powder often has a unique composition which justifies the need for research to study the feasibility of using this stone powder type for ground improvement applications. This paper presents results from a comprehensive laboratory study carried out to investigate the feasibility of using stone powder for improvement of engineering properties of clays.
The stone powder contains bassanite (CaSO4. ½ H
... Show MoreThe biochar prepared from sawdust raw material was applied in this study for the treatment of wastewater polluted with methyl orange dye. The effect of pH (2-11), initial concertation (50-250 mg/L) and time were studied. The isotherm of Langmuir, Frendluch and temkin models studied. The Langmuir model was the best to explain the adsorption process, maximum uptake was 136.67 mg/g at 25Co of methyl orange dye. Equilibrium reached after four hours of contact for most adsorbents.The values of thermodynamic parameters ∆G were negative at various temperatures, so the process spontaneous, while ∆H values were 16683 j/mol and ∆S values was 60.82 j/mol.k.
Background:sThe aims of this study were to evaluate and compare the ability of three different techniques to obdurate simulated lateral canals, evaluate the effect of the main canal curvature on obturation of lateral canals and compare the gutta-percha penetration between coronal and apical lateral canals. Materials and methods: Resin blocks with 30 straight and 30 curved were used in this study. Each canal has two parallel lateral canals. The main canal has 0.3 mm apical diameter and 0.04 taper. The canals were divided into six groups according to canal curvature and obturation techniques used (n=10): Groups C1 and C2: straight and curved canals obturated with continuous wave technique using E&Q masterTM system. Groups O1 and O2: straight
... Show MoreThis paper considers a new Double Integral transform called Double Sumudu-Elzaki transform DSET. The combining of the DSET with a semi-analytical method, namely the variational iteration method DSETVIM, to arrive numerical solution of nonlinear PDEs of Fractional Order derivatives. The proposed dual method property decreases the number of calculations required, so combining these two methods leads to calculating the solution's speed. The suggested technique is tested on four problems. The results demonstrated that solving these types of equations using the DSETVIM was more advantageous and efficient
A total of 172 clinical were obtained over 6 months. Klebsiella spp. was detected in 58 (33.7%) samples with a high percentage 29 (50%) in urine in female and low percentage 1(1.7%) in pus and burn swabs in male, and the vaginal swab was 1(1.7%). The female to male ratio was 3.1:1. PCR detection showed that 51(87.93%) out of 58 produce 108 bp. product with rpoB specific primer that represented K. pneumonia. Whereas 7(12.07%) showed PCR product with 343 bp by K. oxytoca specific primer (peh X), furthermore, the sequences of two selected isolates showed that the species related to K. oxytoca strain CAV1335, and to K. oxytoca strain CAV1374. Five selected isolates were re-tested by the gyr A primer, all were showed specific band product wit
... Show MoreOne hundred specimens (urine and sputum) were collected in sterilized containers from patients attending two hospitals in Baghdad province including: Educational Al-Karama Hospital and Educational Al-Yarmouk Hospital, in which, thirty-eight K. pneumoniae isolate were obtained out of one hundred specimens, all of which are of urine origin. The results obtained in this study showed that Klebsiella pneumoniae isolates were highly resistant to Augmentine (94.7%), also Klebsiella isolates were resistant to Ceftriaxone (86.8%), Cefotaxime (81.5%), and Ceftazidime (65.7%). Very low level of resistance was found toward Imipenem and Meropenem (18.4% and 5.2%) respectively. Only four isolates (10.52 %) were positive for wzy gene; K19, K20, K21, an
... Show MoreA study was carried out in the vineyard at Al- sowayra in the Waset Province to study the effect of boron spray on cluster and fruits traits characteristics of grape cultivar . Borax used was as a source of boron at the concentrations (0.0 , 0.1, 0.2, 0.3, 0.4 and 0.5 ) g / l . Water plus Wetting agent (0.05 g/l detergent) was sprayed to induce faom and reduce water surface tension. The spray was implemented twice, first was one week before blooming and the second was after fruit set. Results showed that spray treatment by boron increased. weight and volume of berries and increased cluster's weight bunch length and diameter besides the increased number of Fruits in bunch also Total Soluble Solids (Tss%) was increased wh
... Show MoreIn the present work the performance of semifluidized bed adsorber was evaluated for removal of phenolic compound from wastewater using commercial activated carbon as adsorbent. P-chlorophenol (4-Chlorophenol) and o-cresol (2-methylphenol) was selected as a phenolic compound for that purpose. The phenols percent removal, in term of breakthrough curves were studied as affected by hydrodynamics limitations which include minimum and maximum semifluidization velocities and packed bed formation in the column by varying various parameters such as inlet liquid superficial velocity (from Uminsf to 8Uminsf m/s), and retaining grid (sometimes referred to as adsorbent loading) to initial static bed height ratio (from 3-4.5). In
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