A bolted–welded hybrid demountable shear connector for use in deconstructable steel–concrete composite buildings and bridges was proposed. The hybrid connector consisted of a partially threaded stud, which was welded on the flange of a steel section, and a machined steel tube with compatible geometry, which was bolted on the stud. Four standard pushout tests according to Eurocode 4 were carried out to assess the shear performance of the hybrid connector. The experimental results show that the initial stiffness, shear resistance, and slip capacity of the proposed connector were higher than those of traditional welded studs. The hybrid connector was a ductile connector, according to Eurocode 4, with slip capacity higher than 6 mm. A nonlinear finite-element model was calibrated against the pushout tests and found capable of reproducing the experimental behavior with good agreement. The verified finite-element model was then used to conduct a series of parametric studies in order to assess the effect of infilled grout, concrete slab strength, stud diameter, stud tensile strength, tube thickness, and tube tensile strength on the shear resistance and stiffness of the hybrid connector. Based on the experimental and numerical results, a design equation is proposed for the prediction of the shear resistance of the novel connector.
The ionospheric characteristics exhibit significant variations with the solar cycle, geomagnetic conditions, seasons, latitudes and even local time. Representation of this research focused on global distribution of electron (Te) and ion temperatures (Ti) during great and severe geomagnetic storms (GMS), their daily and seasonally variation for years (2001-2013), variations of electron and ion temperature during GMS with plasma velocity and geographic latitudes. Finally comparison between observed and predicted Te and Ti get from IRI model during the two kinds of storm selected. Data from satellite Defense Meteorological Satellite Program (DMSP) 850 km altitude are taken for Te, Ti and plasma velocity for different latitudes during great
... Show MoreThe current research reports the preparation and fabrication of the silver paste conductor which is employed as a soldering material for electro – optical components ohmic interconnections. The prepared paste possesses electrical characteristics identical to the ohmic connectors as its observable from resistance – temperature variation. Moreover, the I – V characteristics obeys Ohm’s law and this dependency was further confirmed by the nearly constant capacitance measurements with voltage and frequency. A noticeable improvement in electrical conductivity, compared to the pure silver paste sample, was noted for samples prepared by mixing predetermined weight ratios of brass and copper. Furthermore, stability of electrical resistan
... Show MoreThe concept of rehabilitation provided an essential richness in the conservation philosophy through sustaining buildings life and adapting them to the contemporary use through a vision which looks at the present and future . In Iraq , the existence of historical buildings and the traditional fabric in the cities required the urban development which enhanced the interests of planning and architectural fields especially the building rehabilitation which requires the architectural intervention , and all that led to elaborate the problem of research which is " The confusion in the concepts of monumental, historical and traditional buildings in Iraq, As well as The insufficient knowledge about rehabilitation and the acts related to it through
... Show Moreالضاد والظاء موطن تفرد العربية وفخرها ، الفت فيهما العشرات والعشرات من المصنفات الثرّة لكثرة ذرائع تلابسهما والخلط بينهما ، فهما متشابهان في هيكل البناء ، وإخراجهما متداخل على اللسان ، وألفاظهما متناظرة برحابة في الإملاء ، فضلاعن اشكالهما إلى حدّ الآن ، مما حثني على التفكير في وسائل تسهل المطروح وتمد جسراً بين أجزائه عسى أن تدنو قطافه في دفع الشبهة ومواراتها ، فتحصلت لي امور ادرتها بكلمتين مف
... Show MoreSalicylaldehyde was react with 4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-on to produce the Schiff base ligand 2,3-dimethyl-1-phenyl-4-salicylidene-3-pyrazoline-5-on (L). The prepared ligand was identified by Microelemental Analysis, and FT.IR, UV-Vis spectroscopic techniques. A new complexes of Fe(III),Co(II),Ni(II),Cu(II),Ce(III) and Pb(II) with mixed ligands of dithizone (DTZ) and Schiff base were prepared in aqueous ethanol with a 2:2:1 M:L:DTZ. The prepared complexes were characterized using flame atomic absorption, (C.H.N) Analysis, FT.IR and UV-Vis spectroscopic methods as well as magnetic susceptibility and conductivity measurements. In addition biological activity of the ligands and complexes against two selected type of bacteria
... Show MoreAbstract
Disturbs the social system in any society specially in Iraq other than
other Islamic and Arabic countries. That is according to the abnormal
conditions that Iraq has past through as wars and blockage, and lastly the
invasion. Therefore it has been necessary to put this phenomenon under
study and analysis to discover Juvenile Delinquency is one of the most
prominent social phenomenon that the important reasons behind it, and trying
to treat what can be treated of the effects of it upon society.
This study is mainly concerned with the explaining the social factors
leading toward juvenile delinquency trying to crystallize the problem of the
study in the following question: (What are the psychological,
The electro-optic coefficient r63 and r41 are determined in congruent KDP crystals, using an experimental method based upon the direct measurement of material. Sénarmont system for electro-optic coefficient measurement and characterization of crystals was modified. This modification allowed us to obtain on the frequency dispersion dependence of the electro-optic coefficients within a frequency range up to 20 MHz and on a new version of modulation depth method. To the best of our knowledge, by using this system, the electro-optic coefficients r63 and r41 in different configurations (transverse and longitudinal) have been measured for the first time within a frequency range up to 20 MHz. The measurements have been investigated as a functi
... Show MoreIn this paper, a relationship between the liquid limit and the coefficient of consolidation of Iraqi soils are studied. The samples of soil used in study are undisturbed silty clay. These samples are taken from different locations and depths of Middle and South of Iraq by cooperation with Consulting Engineering Bureau- University of Baghdad- College of Engineering. The depth reached about 20 meters. The experimental work is made to calculate the liquid limit and the coefficient of consolidation. From these sites, 280 points are obtained. The relationship between the liquid limit and the coefficient of consolidation is drawn as a curve. This curve is studied and compared with the curve that obtained from other studies. From these curves, it
... Show MoreThe present study was performed to evaluate the level of some risk factors (biochemical and immunological) in hypothyroid Iraqi patients considering the different thyroid functional states (hypothyroidism and subclinical hypothyroidism).The study includes 82 patients clinically diagnosed with hypothyroidism. Three study groups have been investigated: (47 clinical hypothyroid patients, 12 subclinical hypothyroid patients 23 healthy individuals) of different ages. This study, show that the proportion of females (83.3 %), (87.2%) in subclinical and clinical hypothyroidisim respectively higher than the proportion of males (16.7%),(12.8%) in subclinical and clinical hypothyrodism respectively of the total patients.The majority of subclinical hyp
... Show More