In this study, the flexural performance of a new composite beam–slab system filled with concrete material was investigated, where this system was mainly prepared from lightweight cold-formed steel sections of a beam and a deck slab for carrying heavy floor loads as another concept of a conventional composite system with a lower cost impact. For this purpose, seven samples of a profile steel sheet–dry board deck slab (PSSDB/PDS) carried by a steel cold-formed C-purlins beam (CB) were prepared and named “composite CBPDS specimen”, which were tested under a static bending load. Specifically, the effects of the profile steel sheet (PSS) direction (parallel or perpendicular to the span of the specimen) using different C-purlins c
... Show MoreCircular thin walled structures have wide range of applications. This type of structure is generally exposed to different types of loads, but one of the most important types is a buckling. In this work, the phenomena of buckling was studied by using finite element analysis. The circular thin walled structure in this study is constructed from; cylindrical thin shell strengthen by longitudinal stringers, subjected to pure bending in one plane. In addition, Taguchi method was used to identify the optimum combination set of parameters for enhancement of the critical buckling load value, as well as to investigate the most effective parameter. The parameters that have been analyzed were; cylinder shell thickness, shape of stiffeners section an
... Show MoreNaidid worms were sorted from 27 samples of aquatic macrophyta including ceratophyllum demersum , Potamogeton crispus and, Hydrilla verticellat with associated filamentous algae were collected from Euphrates River at Al-Mussayab city, 60 Km southwest Baghdad. The result of sorted worms revealed the presence of eight species of subfamily Naidinae, which are consider as new records for Iraq, including Stephensoniana trivandrana; Paranais frici, Ophidonais serpentine, Specaria josinae, Dero (Dero) evelinae , Dero (Aulophorus) indicus , Nais pseudobtusa and finally N. stolci. This investigation includes morphological descriptions for each species illustrated by identification criteria photos.
Extract from cell culture of medicinal plant like Nigella sativa have been assessed for its cytotoxic properties. Thymol is likely responsible for the theraputic effects of Nigella sativa leaf callus extract. In this short study the inhibitory effect of Nigella sativa leaf callus extract (Thymol) has been studied on Human Lorgnx Epidrmoid Carcinoma (Hep-2) cell line during different exposure period of time (24, 48 and 72 hrs.) using different concentration of the extract (1000, 500, 400, 300, 200 and 100 µg/ml). The optical density of the Hep-2 cells has been readed on 492 nm wave length. Thymol –induced cytotoxicity was (500 µg/ml) which inhibit cell growing compared to the control and this
... Show MoreDuring the period 1970-2006 the Marshes-land region was exposed to several change into many sides of vanishing steeling and growth as follow :
1- Drying this region after 1991,and re-flooded again during 2003. Many other large Marsh-land, like al-Hawaisa was dried by cutting off inlet-water fed from Iran sources .As asqunance there are transferred to different kinds of swamps ,followed by major change in the structure of the region as the rural settlement concerned. Rural settlement in this area starts new push of migration. The research did not take that in consideration in this thesis because some others took it in details in some thesis and researches. The situation of Marsh-land is getting anew face after those major changes which
The esterification of oleic acid with 2-ethylhexanol in presence of sulfuric acid as homogeneous catalyst was investigated in this work to produce 2-ethylhexyl oleate (biodiesel) by using semi batch reactive distillation. The effect of reaction temperature (100 to 130°C), 2-ethylhexanol:oleic acid molar ratio (1:1 to 1:3) and catalysts concentration (0.2 to 1wt%) were studied. Higher conversion of 97% was achieved with operating conditions of reaction temperature of 130°C, molar ratio of free fatty acid to alcohol of 1:2 and catalyst concentration of 1wt%. A simulation was adopted from basic principles of the reactive distillation using MATLAB to describe the process. Good agreement was achieved.
Surface water samples from different locations within Tigris River's boundaries in Baghdad city have been analyzed for drinking purposes. Correlation coefficients among different parameters were determined. An attempt has been made to develop linear regression equations to predict the concentration of water quality constituents having significant correlation coefficients with electrical conductivity (EC). This study aims to find five regression models produced and validated using electrical conductivity as a predictor to predict total hardness (TH), calcium (Ca), chloride (Cl), sulfate (SO4), and total dissolved solids (TDS). The five models showed good/excellent prediction ability of the parameters mentioned
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