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.
Flexible pavements are considered an essential element of transportation infrastructure. So, evaluations of flexible pavement performance are necessary for the proper management of transportation infrastructure. Pavement condition index (PCI) and international roughness index (IRI) are common indices applied to evaluate pavement surface conditions. However, the pavement condition surveys to calculate PCI are costly and time-consuming as compared to IRI. This article focuses on developing regression models that predict PCI from IRI. Eighty-three flexible pavement sections, with section length equal to 250 m, were selected in Al-Diwaniyah, Iraq, to develop PCI-IRI relationships. In terms of the quantity and severity of eac
... Show MoreIn this research, porous silicon (PS) prepared by anodization etching on surface of single crystalline p-type Si wafer, then Gold nanoparticle (AuNPs) prepared by pulsed laser ablation in liquid. NPs deposited on PS layer by drop casting. The morphology of PS, AuNPs and AuNPs/PS samples were examined by AFM. The crystallization of this sample was characterized by X-ray diffraction (XRD). The electrical properties and sensitivity to CO2 gas were investigated to Al/AuNPs/PS/c-Si/Al, we found that AuNPs plays crucial role to enhance this properties.
In this paper,the homtopy perturbation method (HPM) was applied to obtain the approximate solutions of the fractional order integro-differential equations . The fractional order derivatives and fractional order integral are described in the Caputo and Riemann-Liouville sense respectively. We can easily obtain the solution from convergent the infinite series of HPM . A theorem for convergence and error estimates of the HPM for solving fractional order integro-differential equations was given. Moreover, numerical results show that our theoretical analysis are accurate and the HPM can be considered as a powerful method for solving fractional order integro-diffrential equations.
... Show MoreThe research aims to analyze and evaluate the urban land use according to the needs of the current and future population by adopting the planning criteria for the holy city of Karbala. In the theoretical side, we discussed the most important concepts of urban land use planning. In the practical aspect of the study, field surveys were conducted to obtain the required information. Using the GIS program, the land uses were planned and executed, Analysis By comparing the per capita use of urban land with criteria and the production of maps.
The main findings of the study are that there is a large deficit in meeting some of the needs of the urban land uses and the basic services of the city. The research recommended that the needs of
... Show MoreTo ensure fault tolerance and distributed management, distributed protocols are employed as one of the major architectural concepts underlying the Internet. However, inefficiency, instability and fragility could be potentially overcome with the help of the novel networking architecture called software-defined networking (SDN). The main property of this architecture is the separation of the control and data planes. To reduce congestion and thus improve latency and throughput, there must be homogeneous distribution of the traffic load over the different network paths. This paper presents a smart flow steering agent (SFSA) for data flow routing based on current network conditions. To enhance throughput and minimize latency, the SFSA distrib
... Show MoreIn this research study failed Annunciation No. 10 for the fourth phase of the pressure of carbon dioxide of the company for Southern Fertilizers and repeated the failures more than once for the same gospel was a detailed study of the gospel included a series tests for properties Mechanical and Structural addition to the tests microscopic and scanning electron microscope shows m This study parameters and a failure Elal well as the existence of an old internal cracks in the metal of the Annunciation
The survival analysis is one of the modern methods of analysis that is based on the fact that the dependent variable represents time until the event concerned in the study. There are many survival models that deal with the impact of explanatory factors on the likelihood of survival, including the models proposed by the world, David Cox, one of the most important and common models of survival, where it consists of two functions, one of which is a parametric function that does not depend on the survival time and the other a nonparametric function that depends on times of survival, which the Cox model is defined as a semi parametric model, The set of parametric models that depend on the time-to-event distribution parameters such as
... Show MoreBackground: Obesity is a global health issue. Laparoscopic sleeve gastrectomy has progressively become the most popular procedure among the surgical community as a definitive bariatric operation. The increasing number of surgeries performed will be likely be followed by increasing reports of patients experiencing weight loss failure.
Objectives: To determine the effectiveness of conversion from laparoscopic sleeve gastrectomy to Roux-en-Y gastric bypass in cases with weight loss failure.
Patient &methods: The retrospective review of patients who had operated with laparoscopic sleeve gastrectomy from October 2009 to January 2016 at Saint Raphael hospital, 21 patients includ
According to Chandra Survey Observatory Near-Asteroid Belt Comets, the solar wind's contact with the comet produces a variety of spectral characteristics. The study of X-ray spectra produced by charge exchange is presented here. The spectrum of a comet can reveal a lot about its composition. This study has concentrated on the elemental abundance in six different comets, including 17P/Holmes, C/1999T1, C/2013A1, 9p/Temple1, and 103p/Hartley2 (NEAT). Numerous aspects of the comet's dynamics allow it to behave in a unique manner as it gets closer to the Near-Asteroid Belt. These characteristics are being examined, and some studies are still ongoing. The computations allow us to observe, for instance, how the composition of
... Show MoreAspergillus niger is one of the most important filamentous fungi that used in the fermentation industry. Aspergillus niger isolate was cultured on potato-dextrose agar (PDA) for activation, and the optimum conditions for xylanase production from this local isolate were studied by solid state fermentation, using a medium composed of wheat bran moisten with corn steep liquor at ratio 1:0.5 (v:w) at initial pH 5.5, inoc-ulated with 1.6 × 106 spores/ml, and incubated at 30ᵒC for 5 days.