This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results s

After the democratic transformation in 2003 in Iraq, young people waited a lot to take their real opportunity to participate in politics, but most of the laws regulating political and electoral work have been unfair to young people, despite developments in laws and legislation, but opportunities did not allow young people to participate in politics, which was reflected It negatively affected their participation in voting and nomination, and even their assumption of public office and positions, which is why they complained about the ruling class and the political system through protests, or when they refused to vote, and this is reflected in the recent parliamentary elections and low participation rates

Background: The final stage of endodontic therapy is complete obturation of the root canal system to provide as perfect as possible at the cementodentinal junction of the apical foramen. The purpose of this in vitro study was to evaluate the sealing ability of injection molded thermoplasticized gutta percha and lateral condensation techniques with and without the use of sealers. Materials and Methods: Forty freshly extracted adult human maxillary central incisors with complete formed apices were utilized in this study. The teeth were randomly divided into four groups for evaluation of the apical seal. Group (1) lateral condensation gutta percha technique without sealer, (2) lateral condensation gutta percha technique with sealer, (3) Inject

The heavy metals Cd, Cu, Fe, pb, and Zn were determined in dissolved and particulate phases of the water,in addition to exchangeable and residual phases of the sediment and in the selected organs of the fish Cyprinus carpio collected from the Euphrates River near Al-Nassiriya city center south of Iraq during the summer period / 2009 .Also sediment texture and total organic carbon(TOC) were measured. Analysis emploing a flam Atomic Absorption Spectrophotometers . The mean regional concentrations of the heavy metals in dissolved (µg/l) and particulate phases (µg/gm) dry weight were Cd (0.15,16.13) ,Cu (0.59,24.48) ,Fe (726,909.4) ,Pb (0.20, 49.95) and Zn (2.5,35.62) respectively,and those for exchangeable and residual phases of the

The removal of heavy metal ions from wastewater by ion exchange resins ( zeolite and purolite C105), was investigated. The adsorption process, which is pH dependent, shows maximum removal of metal ions at pH 6 and 7 for zeolite and purolite C105 for initial metal ion
concentrations of 50-250 mg/l, with resin dose of 0.25-3 g. The maximum ion exchange capacity was found to be 9.74, 9.23 and 9.71 mg/g for Cu2+, Pb2+, and Ni2+ on zeolite respectively, while on purolite C105 the maximum ion exchange capacity was found to be 9.64 ,8.73 and 9.39 for Cu2+, Pb2+, and Ni2+ respectively. The maximum removal was 97-98% for Cu2+ and Ni2+ and 92- 93% for Pb2+ on zeolite, while it was 93-94% for Cu2+, 96-97% for Ni2+, and 87-88% for Pb2+ on puroli

Background: The purpose of this study was to compare regional bond strength at middle and cervical thirds of the root canal among glass fiber-reinforced composite (FRC) endodontic posts cemented with different cements, using the push-out test to compare the performance (retention) of two types of luting cements; polycarboxylate cement and Zinc phosphate cement used to cement translucent fiber post and to compare the result of the push-out test at different storage times;1 week ,1month and 2 months. Materials and methods: Ninety caries-free, recently extracted single-rooted human teeth with straight root canals was used in this study, The root canals were endodontically instrumented at a working length of 0.5 mm from the apex by m

Isolation had been done for active substances from Thyme plant (Thymus Vulgaris) such as volatile oils, Saponins and Tannins. The percentage in form was (21.1%),(59.2%),( 9.7%) respectively. Also a study of anti-bacterial activity of extracts from Thyme using two types of pathogenic bacteria Escherichia Coli and aurous Staphylococcus showed the ability of inhibition for all different extracts by vary inhibition diameters for different active substances, concentrations and bacteria. One type of cancer cellular line used to study the effect of Thyme extracts on the growth of cells in the laboratory and thus know the specifications of extracts as anti-tumor, (L20B) cell line have been used which is mice Transformed cell Line. The possibility o

Heavy metals are currently of much environmental concern. The contamination by heavy metals in plants and water is one of the major issues to be faced throughout the world. This research is tried to estimate levels of heavy metals in vegetative crops and soil irrigated with well water (as alternative source for irrigation). Samples of well water, soil and vegetative crops were collected from agriculture fields at Al-Dora district in Baghdad. Physico-chemical parameters (pH, EC, TDS and Salinity) were measured for water and (pH, EC and salinity) for soil samples. Estimation of Lead (Pb), Nickle (Ni), Zinc (Zn) and Iron (Fe) concentrations in water, vegetable crops (Raphanus sativus, Apium graveoleus, Beta vulgaris, Allium ampeloprasum, Le