50 research outputs found

    Synthesis, Characterization, Crystal Structure, and Biological Studies of a Cadmium(II) Complex with a Tridentate Ligand 4′-Chloro-2,2′:6′,2′′-Terpyridine

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    A new Cd(II) complex with the ligand 4′-chloro-2,2′6′,2′′-terpyridine (Cltpy), [Cd(Cltpy)(I)2], has been synthesized and characterized by CHN elemental analysis, 1H-NMR, 13C-NMR, and IR spectroscopy and structurally analyzed by X-ray single-crystal diffraction. The single-crystal X-ray analyses show that the coordination number in complex is five with three terpyridine (Cltpy) N-donor atoms and two iodine atoms. The antibacterial activities of Cltpy and its Cd(II) complex are tested against different bacteria

    A new conventional criterion for the performance evaluation of gang saw machines

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    Available online 20 June 2019The process of cutting dimension stones by gang saw machines plays a vital role in the productivity and efficiency of quarries and stone cutting factories. The maximum electrical current (MEC) is a key variable for assessing this process. This paper proposes two new models based on multiple linear regression (MLP) and a robust non-linear algorithm of gene expression programming (GEP) to predict MEC. To do so, the parameters of Mohs hardness (Mh), uniaxial compressive strength (UCS), Schimazek’s F-abrasiveness factor (SF-a), Young’s modulus (YM) and production rate (Pr) were measured as input parameters using laboratory tests. A statistical comparison was made between the developed models and a previous study. The GEP-based model was found to be a reliable and robust modelling approach for predicting MEC. Finally, according to the conducted parametric analysis, Mh was identified as the most influential parameter on MEC prediction.Sina Shaffiee Haghshenas, Roohollah Shirani Faradonbeh, Reza Mikaeil, Sami Shaffiee Haghshenas, Abbas Taheri, Amir Saghatforoush, Alireza Dormish

    Solutions to Overcome Barriers of Implementing Constructability, Operability, and Maintainability (COM) Concepts in Infrastructure Projects: A Meta-Synthesis Approach.

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    Construction managers in infrastructure projects in different societies offer and use approaches that can conclude each project’s triangle of cost, time, and quality in the most optimal mode, satisfying important needs of the projects. One of these approaches is benefiting from concepts of Constructability, Operability, and Maintainability (the threefold concepts of COM), which can satisfy such need in infrastructure projects. In order to implement each approach, while the desired approach is innovative, as well, there are some barriers. It is significantly required to offer solutions to obtain desired results from that approach. Therefore, the aim of this research is presenting solutions to overcome existing barriers in implementing the threefold concepts of COM in infrastructure projects. For that, the Meta-Synthesis method is applied, which is placed in qualitative research category. In order to analyze collected data, descriptive and pattern coding techniques have been used. As the result of this study, a systematic classification of the solutions to overcome barriers of implementing the threefold concepts of COM in infrastructure projects is presented. The aim of construction managers is successful delivery of projects, for that, it is suggested to use such approaches that result in integration of different project life cycle phases. This facilitates optimization of project time and cost, aiming to provide a better quality of constructions. Therefore, in order to achieve infrastructure projects main objectives, such approaches are to be used, and in order to overcome barriers in implementing them, some solutions are to be identified, classified and presented

    Preparation of Zinc (II) and Cadmium (II) Complexes of the Tetradentate Schiff Base Ligand 2-((E)-(2-(2-(pyridine-2-yl)- ethylthio)ethylimino)methyl)-4-bromophenol (PytBrsalH)

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    We describe the synthesis and characterization of two new zinc (II) andcadmium (II) complexes of the tetradentate dissymmetric Schiff base ligand 2-((E)-(2-(2-(pyridine-2-yl)ethylthio)ethylimino)methyl)-4-bromophenol (PytBrsalH), prepared from 1-(2-pyridyl)-3-thia-5-aminopentane (pyta) and 5-bromosalicylaldehyde. The complexeswere synthesized by treating an ethanolic solution of the ligand with equimolar amounts ofappropriate metal salts in 1 M methanolic solution of NaOH or alternatively, by a moredirect route in which the two reactants are added to a solution of the ligand immediatelyafter formation of the latter and prior to any isolation. The complexes were characterizedby elemental analysis, FTIR, 1H-NMR, electronic spectra and molar conductivity.According to obtained data, the probable coordination geometries of zinc and cadmium inthese complexes with mixed N, S and O donor atoms are tetrahedral- and octahedral-like,respectively. Both complexes were found to be 1:1 electrolyte systems in acetonitrile
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