The use of external posttensioning technique for strengthening reinforced concrete girders has been considerably studied by many researchers worldwide. However, no available data are seen regarding strengthening full-scale composite prestressed concrete girders with external posttensioned technique under static and repeated loading. In this research, four full-scale composite prestressed I-shape girders of 16 m span were fabricated and tested under static and repeated loading up to failure. Accordingly, two girders were externally strengthened with posttensioned strands, while the other two girders were left without strengthening. The experimental tests include deflection, cracking load, ultimate strength and strains at midspan, and loading stages. Test results were compared with the design expressions mentioned in AASHTO LRFD specifications and ACI 318-2014 code. Also, a nonlinear analysis was conducted using the finite element method (FEM). The presented analysis models were verified by comparing the model results with test results. The general theme abstracted from both experimental tests and numerical analysis reflects that the performance and procedure of strengthening with external prestressing of girders were found to be effective in increasing the load carrying capacity of the strengthened girders.
ABSTRACT
This research included the preparation and characterization of new demulsifies from natural and synthetic polymers of chitosan and polyvinyl alcohol that are environmentally friendly and at the same time have high efficacy comparable to emulsifiers. imported foreign. The prepared compounds were examined using infrared spectroscopy and nuclear magnetic resonance spectroscopy, and all the spectral signals of the polymers were in good agreement with the chemical composition of the polymers. And the melting and decomposition that occur on polymers at high temperatures. The effect of the length and type of side chain in the compositions of polymers on the process of water separation of oil emulsions w
... Show MoreFor the purpose of determining the impact of three levels of nitrogen fertilizer (0, 60, and 120 kg.ha-1) and sulfur fertilizer (0, 40, and 60 kg.ha-1) on production and growth indicators (number of leaves, number of branches, chlorophyll pigments, and fresh and dry weights), a field experiment was carried out during the winter season (2021/2022) in the fields of Al-Diwaniyah Province, Ministry of Agriculture, Diwaniyah Agriculture Directorate, Al-Nouriyah Forest Division. Means were compared using the least significant difference test (LSD) at a 0.05 level of probability. In a factorial experiment employing a wholly randomized block design wi
The present research deal with ecological and geographical distribution of species and genera of Primulaceae in Iraq. The results were revealed that species distributed in the north , north-east and west of Iraq. Anagallis arvensis L. is the most prevalent species tolerant to different environmental conditions, while the species of Primula L. characterized as less widespread and limited in one District. In addition, the districts Rawanduz (MRO) and Sulaymaniyah (MSU) have ranked first in distribution of the species on geographical districts with (75%), while the districts southern desert (DSD) and Basra (LBA) in last place with (16.7%). Maps for geographical distribution for all species were illustrated.
In this research two series of the new derivatives of Trimethoprim and paracetamol drugs have been prepared which known as a high medicinal effectiveness. Series (A) is including the interaction of diazonium salt of trimethoprim and coupling with some substituted phenol compounds (2-amino phenol, 3-ethyl phenol, 1-naphthol, 2-nitro phenol, Salbutamol). Series (B) is including the interaction coupling alkali solution of paracetamol with diazonium salt of some substituted aniline compounds (Benzedine, 2, 3-di chloro aniline, Trimethoprim, Anilinium chloride, 2-nitro- 4-chloro aniline).Chemical structures of all synthesized compounds were confirmed by UV-visible and FTIR spectroscopy.
Abstract This study aims to discover the ways that adopted by extremism to expand to new geographical areas, in order to spread out its ideology, which led to create new geo-strategic zone, aims to recognize ISIS’s strategy to move towards new geographic locations and the motivations behind these transformations, the study also analyses all aspects of this strategy, the group’s relationship with other terrorist groups in these areas and limits of the competition between them. The study also highlights the factors that have led ISIS to move to new geographical areas and its techniques to control them.