Deconstructable Flush End Plate Beam-to-Column Composite Joints: Component- Based Modelling

[EN] Within a paradigm of designing building structures for their end-of-life deconstruction, thispaper addresses flush end plate beam-to-column composite joints that may be dis-assembledand reused elsewhere. The joints consist of steel beams bolted to steel columns, and these aremade composite over the joint with precast concrete slabs attached to the top flange of thesteel beams with post-tensioned high strength bolted shear connectors installed in clearanceholes. Joints of this type experience partial shear connection, and accordingly their designneeds to incorporate this effect. Experimental work reported elsewhere by the authors showsthat a structural system of this type may indeed be deconstructed, even when loaded beyondthe serviceability limit state, and that the moment-rotation response is both robust andductile. A numerical modelling using ABAQUS software is introduced in the paper, and theresults of this are used identify the parameters most influential in the structural response,and to propose equations for the initial stiffness, moment capacity and rotation capacity of ajoint. These equations are consistent with the component-based representation of theEurocode 4 and draft Australian AS2327 composite structures standard.The work in this paper was supported by the Australian Research Council through an Australian Laureate Fellowship (FL100100063) and a Discovery Project (DP150100446) awarded to the first author. This support is gratefully acknowledged.Bradford, M.; Ataei, A.; Liu, X. (2018). Deconstructable Flush End Plate Beam-to-Column Composite Joints: Component- Based Modelling. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 601-606. https://doi.org/10.4995/ASCCS2018.2018.7296OCS60160

Sustainable high strength steel flush end plate beam-tocolumn composite joints with deconstructable bolted shear connectors

The design of engineering structures for deconstructability can reduce the energy and cost required for their demolition and the disposal of their construction waste, and it also enhances the sustainability of a building by allowing for easy dismantling and the reuse or recycling of structural components and construction materials at the end of the service life of the building. In addition, using high performance materials such as High Strength Steel (HSS) can improve the sustainability of a structure by providing for higher design stresses and accordingly reducing the self-weight of the structure. This paper describes the results of four full-scale beam-to-column deconstructable composite joints with HSS S690 flush end plates. The structural behaviour of the new system in conjunction with application of post-installed friction-grip bolted shear connectors for developing deconstructable composite floors is investigated. The test results show that the proposed composite beam-tocolumn joints can provide the required strength and ductility according to EC3 and EC4 specifications, and that the system can be easily deconstructed at the end of the service life of the structure as a proof of concept

Grade Uncertainty and its Impact on Ore Grade Reconciliation between the Resource Model and the Mine

Major differences between estimated grade and actual grade are a usual problem in many open pit mines. The estimated grade is predicted in exploration stage from data obtained from boreholes, whereas the actual grade would be determined only after the mining operation. The poor reconciliation between the values of estimated and actual grades can cause major economic losses to the mining industry. Many different factors affect the reconciliation process in a mining operation. The nature of the orebody, the random uncertainty and the systematic errors are three main sources affecting the reconciliation process in exploration stage of the orebody. In this paper each source of uncertainty is studied and a probabilistic model is presented to determine the role of each item in total uncertainty of the grade parameter. The model ability was investigated in the study of real data taken from an iron open pit mine in Iran. The results showed the systematic uncertainty, the nature of the orebody and the random uncertainty are the main causes of poor reconciliation in the case study respectively

Performance of bolted connections in deconstructable composite frames

The design of engineering structures for deconstructability can reduce the energy and cost required for their demolition and the disposal of their construction waste, and it also enhances the sustainability of a building by allowing for easy dismantling and the reuse or recycling of structural components and construction materials at the end of the service life of the building. In addition, using high performance materials such as High Strength Steel (HSS) can improve the sustainability of a structure by providing for higher design stresses and accordingly reducing the self-weight of the structure. This paper describes the results of four full-scale beam-to-column deconstructable composite joints with HSS S690 flush end plates. The structural behaviour of the new system in conjunction with application of post-installed friction-grip bolted shear connectors for developing deconstructable composite floors is investigated. The test results show that the proposed composite beam-tocolumn joints can provide the required strength and ductility according to EC3 and EC4 specifications, and that the system can be easily deconstructed at the end of the service life of the structure as a proof of concept

Study of clonal variation of 'Bidaneh Ghermez' grapevine cultivar in Iran

ArticleGrapevine (Vitis vinifera L.) is a well - known plant including different cultivars and clones. In spite of the extensive works at the cultivar level, identification and determination of clonal genetic variation has remained as a challenge. To assess the genetic variation between clones of grapevine cv. 'Bidaneh Ghermez', 20 selected clones were analyzed for cluster weight (CW), cluster length (CL), cluster width (CWI), berry weight (BW), berry length (BL), berry width (BWI) and total soluble solids (TSS) in randomized complete block design with three replications. Analysis of variance reveale d considerable genetic variation for all measured traits (except cluster width) among clones. Cluster analysis, discriminant function analysis and principal component analysis (PCA) showed same results and all clones assigned in 2 groups. First group was including 9 clones and second group was including 11 clones. Overall, our results indicated C7, C10, C12 and C14 clones were best clones and have potential to introduce promising clones for stablishing new vineyard with high yield

Antiviral effects of Lactobacillus crispatus against HSV-2 in mammalian cell lines

Background: Herpes simplex virus type 2 (HSV-2) infectious disease is one of the most common viral sexually transmitted diseases. As regards, vaginal lactobacilli play an important role in protecting host against the urogenital pathogens; here we assessed the potential antiviral activity of Lactobacillus crispatus against HSV-2 infection in vitro. Methods: Both Vero and HeLa cell lines were treated by L. crispatus before, during and after HSV-2 infection. The pre-incubation assay was also performed for the evaluating of virus adsorption by L. crispatus. Virus titer reduction in each stage was determined by a plaque reduction assay. Results: L. crispatus significantly decreased the infectivity of the HSV-2 in initial steps on both cell lines; however, no significant inhibition was ascertained during adsorption and multiplication process. The lactobacilli adhere on Vero cells two-fold stronger than HeLa and subsequently protect the Vero cells nearly 2.5 fold higher than HeLa cell against the virion. Co-incubation of HSV-2 with bacterial cells prior to virus inoculation significantly decreased the virus titer. Conclusion: L. crispatus appears to inhibit the entry of the virus into cells by trapping HSV-2 particles. In addition, formation of L. crispatus microcolonies in the cell surface could block HSV-2 receptors and prevent viral entry to cells in initial infection steps. © 201

Development of a latex agglutination method for diagnosis of rotavirus infections

Background: Rotavirus is a major cause of morbidity and mortality among children with gastroenteritis. Since the discovery of rotaviruses, several techniques have been used for their laboratory diagnosis; those included Electron Microscopy (EM) and enzyme immunoassay. These methods, however, are expensive and not readily available everywhere. We have developed a technique which can be used for routine diagnosis of rotavirus gastroenteritis. Methods: Purified simian rotavirus, SA11, was injected into rabbits and the γ-globulin fraction of antisera was purified and used for coating of latex beads. The prepared sensitizied latex was then used for agglutination test on fecal samples. 94 stool samples from infants with acute gastroenteritis were tested by (EM), enzyme immunoassay and Latex Agglutination (LA) method. Results: The sensitivity of enzyme immune assay and (LA) were 92.5 and 90, respectively; the specificity of both tests was 98.1 as compared with (EM). Conclusion: Latex Agglutination Test (LAT) is a simple and relatively inexpensive test which can be used for diagnosis of rotavirus gastroenteritis in diagnostic laboratories and health centers

The evolution of food security: where are we now, where should we go next?

Food security is one of the most challenging topics globally; however, the concept of food security has taken on additional dimensions that are general and are less detailed. This study aims to identify the intellectual structure of food security research and the changes in this structure. This paper analyzed 3169 documents from the Web of Science database through a bibliometric review. A review of the published documents shows an increasing trend over the past 46 years. In accordance with co-occurrence analysis, 125 keywords were grouped into five clusters: food security and sustainable development; food security and socioeconomic factors; food security policy and governance; coping strategies for poverty, inequality, and hunger; and modern food security management. This study identifies four streams within food security research: sustainability and environmental, socioeconomic, cultural, and political factors. The paper concludes that even though food security might investigate many significant areas, other new dimensions should still be considered. Further gaps in the literature emerge that present avenues for future research directions. Reviewing indicators and techniques of food security assessment and identifying high-risk groups should be a priority

Socio-economic, cultural, physical and ecological impact assessment of Kavar irrigation and drainage network in Iran

Environmental impacts assessment may be some measures to offset the impact to an acceptable level or explore new solutions. The research was conducted with the aim of assessing the socio-economic, cultural, physical and ecological impacts of Kavar irrigation and drainage network in Fars Province (Iran). In this study, Environmental impacts assessment was undertaken by ICOLD matrix. The ICOLD matrix is one of the flexible methods that converted qualitative data into quantitative data. In this method, the effect of the project activities on the environmental components were assessed in two stages; project construction and operation based on physical, ecological, socio-economic and cultural aspects. The findings indicated that positive effects will be generally exerted on the region environment by establishing and operating irrigation and drainage network in Kavar plain. In other words, substantial positive impacts will be seen in the region consequently; such as improving the average level of aquifer, enhancement of agricultural wells, and agriculture development in the region. However, in order to alleviate the negative impacts of the projects processes, it is suggested that presented environmental training to farmers, collaborating and further communicating with other relevant organizations and institutions.  </strong

Sandwich structure polymer electrolyte membranes containing phosphotungstic acid immobilized electospun nanofibers

The advances in proton exchange membranes (PEM)s is critical for improving the performance of fuel cells [1]. Membranes compromising perfluorosulfonic acid polymers such as Nafion have been used extensively due to their desired conductivity and stability. However, these materials need to be saturated with water to obtain practical level of proton conductivity. There is a strong demand for the PEMs to work at lower relative humidity or under anhydrous conditions because the electrochemical reactions will be accelerated and water management of fuel cell will be simpler. Various designing strategies and advanced materials have been developed to mitigate for this issue without causing serious loss in proton conductivity or stability [2]. Among all, the introducing of inorganic proton conductors such as heteropoly acids have been considered widely. Generally, HPAs (such as phosphotungstic acid H3PW12O40, PWA) have a very strong Brønsted acidity approaching the superacid region (more acidic than Nafion) [3]. In this work, high level of PWA was self-anchored onto nylon electrospun nanofiberous sheet (Figure 1b). Sandwich structured proton conducting membranes were fabricate by assembling nanofibrous central layer with outer Nafion layers (Figure 1b). Since the PWA is attached to the polymer backbones, the risk of leaching out is minimized. Moreover, the significant synthetic versatility of the method helps to increase PWA immobilization level. As shown in the Figure 1c, proton conductivity of as high as 60 mS cm-1 at 30 °C was achieved which is comparable with Nafion 115. The durability of the proton conductivity of sandwiched membrane