A novel welded demountable shear connector for sustainable steel-concrete composite structures is proposed. The proposed connector consists of a grout-filled steel tube bolted to a compatible partially threaded stud, which is welded on a steel section. This connector allows for an easy deconstruction at the end of the service life of a building, promoting the reuse of both the concrete slabs and the steel sections. This paper presents the experimental evaluation of the structural behavior of the proposed connector using a horizontal pushout test arrangement. The effects of various parameters, including the tube thickness, the presence of grout infill, and the concrete slab compressive strength, were assessed. A nonlinear finite element model was also calibrated against the experimental results, and the validated numerical model was used to extend the validity of the experimental results and to perform further parametric studies. The experimental and numerical results show that the tested connectors have similar stiffness, but higher shear resistance and slip capacity compared with traditional welded shear studs and can be classified as ductile according to Eurocode 4.
Background: Vibration decreases the viscosity of composite, making it flow and readily fit the walls of the cavity. This study is initiated to see how this improved adaptation of the composite resin to the cavity walls will affect microleakage using different curing modes
Materials and methods: Standard Class V cavities were prepared on the buccal surface of sixty extracted premolars. Teeth were randomly assigned into two groups (n=30) according to the composite condensation (vibration and conventional) technique, then subdivided into three subgroups (n=10) according to light curing modes (LED-Ramp, LED-Fast and Halogen Continuous modes). Cavities were etched and bonded with Single Bond Universal
... Show MoreThe presence and prevalence of V. cholerae were investigated in forty five water samples collected from different locations of Tiger River/ Baghdad city. Twenty one isolates were isolated by adopting a simple isolation techniques. The final identification revealed that only three isolates were confirmed as V. cholerae. They were named 1J, 1R and Dial 131 which are all serogrouped as non-O1. Toxin Coregulated Pili (TCP) and heat labile enterotoxin (LT) were determined in only the environmental isolate 1J while non of the isolates produced heat stabile toxin (ST). The purification scheme was improved, few steps were adopted to include back extraction of ammonium sulfate, saturation between 80-20%, desalting through Sephadex G25, and gel filt
... Show MoreThis research involves studying the influence of increasing the
number of Gaussian points and the style of their distribution, on a circular exit pupil, on the numerical calculations accuracy of the point spread function for an ideal optical system and another system having focus error of (0.25 A. and 0.5 A. )
It was shown that the accuracy of the results depends on the type of
distributing points on the exit pupil. Also, the accuracy increases with the increase of the number of points (N) and the increase of aberrations which requires on increas (N).
God Almighty set out to build mosques, and he commanded to seek their architecture, and the competition for them, and allocate them with types of worship that are not valid in others, and to preserve their sanctity and not to be degraded and taken for mundane purposes and special benefits, because they are considered one of the most prominent features of Islam and the rituals of Islamic society, so this research came to show the rule Sharia in various and contemporary issues that are needed by the imams of the mosques, their rulers, and those responsible for them. Among the issues in which they have examined comparative juristic research and reached the most correct opinion are:
Building mosques over or under buildings and factories i
Lithium–Manganese ferrites having the chemical formula (Li0.5-0.5x Mnx Fe2.5-0.5x O4), (0 ≤ x ≤ 1) were prepared by double sintering powder processing. The density of the ferrite increased with Mn content while the porosity was noticed to decrease. The dielectric constant was found to increase at high frequencies more rapidly than the low ones. The dielectric constant found to decrease with Mn content. The decrease in loss factor with frequency agreed with Deby’s type relaxation process. A maximum of dielectric loss factor was observed when the hopping frequency is equal to the external electric field frequency. Manganese substitution reduced the dielectric loss in ferrite. The variation of tanδ with frequency shows a similar na
... Show MoreThe banking system considered as one of the most important intermediate circle between creditor and debtors it is mean the most important funding rings in economic activity, whether finance takes the a consumer or investment form and therefore it is the main base to stimulate economic activity both on the demand side, both consumption and investment and therefore of the main motivating factors for economic growth.
The banking system depends in achieve its goals on the grants and loan recovery, or what is known credit process and according to what the importance referred to the role of the banking system, it is important to ensure the safety and efficiency of the mechanisms of banking device and safety is
... Show MoreThis study was undertaken to shed light on the changes of levels of CP
activity, Cu and Fe in sera of .(53) normaJ non-smoker pregnant's without complication, during three1rimestcrs of pregnancy.
G1 inc.l_ude (I 8) pre nants in the 1' 1 tri nester, G2 19) pret:,rp:all.ts _wear
taken m the 2" tnmester and G3 (16) pregnants m the 3rd trunester.
/\nothe.r ('18) ·serum samples were taken from liealthy non-pregnant wqmen
age matched as control·group G4.
Results bowed a significant steady elevation in CP .p:ctivity and &n
... Show MoreA new ligand [N-(acetyl amino) thioxomethyl] valine was prepared from the reaction of acetyl iso thiocyanate with valine. The ligand was characterized by FT-IR, UV- vis and 1HNMR spectrum, The complexes with some metal ions (M +2 =Co,Ni,Cu,Zn,Cd,Hg) have been prepared and characterized. The structural diagnosis were established by IR,UV-Vis spectrum, flame atomic absorption spectroscopy conductivity and magnetic susceptibility ,the complexes showed tetrahedral geometry around the metal l.
The aim of this work is to study the histological and histochemical structure of the Harderian gland in indigenous pigeons. Samples were obtained from 10 males and 10 females of adult healthy pigeons. Hematoxylin and eosin, Alcian blue (pH 2.5), periodic acid-Schiff and promo phenol blue, stains were used for paraffin section examination. The gland was teardrop like in shape, light brown to pink in color, capsulated with thin connective tissue. It was multilobular compound acinotubular in structure and lined by columnar epithelial cells. Lymphocyte, plasma cells and plasma cells with Russell bodies were present underneath the epithelia of central collecting duct and around the secretory unite. Histochemically; the
... Show MoreAn experiment was conducted in the green garden of Department of Biology/ in College of Education for Pure Sciences Ibn-Al-Haitham/ Baghdad University for the grouth season (2012-2013) to study the effect of three concentrations of gibberellic acid (0, 50, 100) ppm and three concentrations of proline (0, 25, 50) ppm on micronutrients content (Iron (Fe), Zinc (Zn), Manganese (Mn) and Copper (Cu) ppm) in addition to total chlorophyll content (µg. cm-2) for the green part of peas plant (Pisum sativum), pots of (8 kg) soil were used, the experiment was conducted according to complete randomized design (CRD) and three replicates, whereby the experiment included (27) pots, the significant variations were compared between means using least s
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