In order to promote sustainable steel-concrete composite structures, special shear connectors that can facilitate deconstruction are needed. A lockbolt demountable shear connector (LB-DSC), including a grout-filled steel tube embedded in the concrete slab and fastened to a geometrically compatible partial-thread bolt, which is bolted on the steel section's top flange of a composite beam, was proposed. The main drawback of previous similar demountable bolts is the sudden slip of the bolt inside its hole. This bolt has a locked conical seat lug that is secured inside a predrilled compatible counter-sunk hole in the steel section's flange to provide a non-slip bolt-flange connection. Deconstruction is achieved by demounting the tube from the top of the slab by unfastening using a simple modified wrench. The mechanical behaviour of the proposed connector is assessed by four pushout tests that were conducted per Eurocode 4 recommendations. The tests showed high shear resistance, and high stiffness as compared to other DSCs, while the slip capacity results classified the LB-DSC as a ductile shear connector according to Eurocode 4. A refined nonlinear finite element model (FEM) was validated through the tests and reliably reproduced the experimental behaviour. Consequently, the calibrated FEM model was applied to carry out extensive parametric analyses to investigate the strength and geometry effects of concrete slab, infilled grout, tube, and bolt on the structural behaviour of the LB-DSC. On the basis of numerical and experimental results, a design equation is derived to predict the shear resistance of the LB-DSC.
Retreatment Efficacy of Continuous Rotation Versus Reciprocation Kinematic Movements in Removing Gutta-Percha with Calcium Silicate-Based Sealer: SEM Study, Raghad Noori Nawaf*, Ra
The present study aimed to assess the potential impact of serum concentration of undercarboxylated osteocalcin (the active form of osteocalcin) and fibroblast growth factor-23 on the incidence of cardiovascular diseases in type 2 diabetics with carotid artery calcification and the possible association with metabolic changes in relation to glucose and minerals homeostasis.
This study included 52 men with carotid artery calcification type 2 diabetes mellitus. These patients were categorized; as follows: group A includes 30 patients who had cardiovascular disease and group B includes 22 patients who had no cardiovascular disease. These groups were compared with 25 apparently healthy control (Group C).
It has been shown
... Show MorePromoting the production of industrially important aromatic chloroamines over transition-metal nitrides catalysts has emerged as a prominent theme in catalysis. This contribution provides an insight into the reduction mechanism of p-chloronitrobenzene (p-CNB) to p-chloroaniline (p-CAN) over the γ-Mo2N(111) surface by means of density functional theory calculations. The adsorption energies of various molecularly adsorbed modes of p-CNB were computed. Our findings display that, p-CNB prefers to be adsorbed over two distinct adsorption sites, namely, Mo-hollow face-centered cubic (fcc) and N-hollow hexagonal close-packed (hcp) sites with adsorption energies of −32.1 and −38.5 kcal/mol, respectively. We establish that the activation of nit
... Show MoreBackground: Early detection of subclinical left ventricular (LV) systolic dysfunction is crucial and could influence patients' prognosis by aiding the clinician to candidate patients for better management.
Objective: To detect early LV systolic dysfunction in asymptomatic patient with chronic aortic regurgitation by two dimensional speckle tracking echocardiography.
Methods: Sixty one asymptomatic patients with chronic aortic regurgitation, with no ischemic heart diseases (by coronary angiography) or conductive heart diseases, no diabetes mellitus, no hypertension, and no other valvular heart diseases (group 1) and fifty age and sex-matched healthy subjects (
... Show MoreThe aim of this study was to measure the concentration of some heavy metals (Lead, Cadmium ,Iron and Cupper) in blood samples of workers who operate the diesel generator in Baghdad city(Dora, Harthya, Bayaa and Hay al Jameaa ) ,and their effects on Testosterone hormone. The study included two groups: the first control group consisted of 20 normal male (non workers and non smoking), and the second consisted of 20 male (generator workers). Blood samples were collected from each two groups, where each sample was divided into two parts, the first part estimated blood concentrations of heavy metals while the second tested testosterone. Data were treated statistically using (Statistical Analysis System 2012) program, and the
... Show MoreUrban land price is the primary indicator of land development in urban areas. Land prices in holly cities have rapidly increased due to tourism and religious activities. Public agencies are usually facing challenges in managing land prices in religious areas. Therefore, they require developed models or tools to understand land prices within religious cities. Predicting land prices can efficiently retain future management and develop urban lands within religious cities. This study proposed a new methodology to predict urban land prices within holy cities. The methodology is based on two models, Linear Regression (LR) and Support Vector Regression (SVR), and nine variables (land price, land area,
... Show MoreObjective: To assess the Impact of Socio-economic status on age at menarche among secondary school students at
AL-Dora city in Baghdad, Iraq.
Methodology: This is a cross sectional study with multi-stage sampling was carried out during the period from the
3
th of December2013 to 12th of March 2014. The Sample comprised of 1760 girls, 1510 girls from urban area and
250 from rural area was included in the study. In first stage, selection of schools was done, and one class was
selected randomly from each level of Education, The data collection through a special questionnaire which Contain
the age of girl by year, class level, birth order, number of household, number of rooms, residency (urban/rural),
education level
The δ-mixing of γ-transitions in 70As populated in the 32 70 70 33 ( , ) Ge p n As γ
reaction is
calculated in the present work by using the a2-ratio methods. In one work we applied this method for two cases, the first one is for pure transition and the sacend one is for non pure transition, We take into account the experimental a2-coefficient for previous works and δ -values for one transition only.The results obtained are, in general, in a good agreement within associated errors, with those reported previously , the discrepancies that occur are due to inaccuracies existing in the experimental data of the previous works.
A new compound 2-(4-methoxyphcnyl)-5-(4-aminophenyl)-1,3,4-
oxadiazole (VI) was prepared by intramol ecular condensation reaction followed by elimination of some simple moieties such as IhO and HCI by using POCI3 with acid hydrazide. A series of new ShiffsÂ
bases 2-(4-methoxyphenyl)-5-[4(4:alkoxybenzoyloxy) benzylidene amino phenyl] I,3,4-oxadia:t.ole (VII].was synthesized from treatment
of oxadiazole derivative [VI] with an appropriate aromatic aldehyde
(IU). Struct\lfe of the resulting products have been ascertaim:d by their melting pointS, elemental analysis ( some of them) and spectral data.