Synthesis and characterization of nanocomposite NiFe2O4@SalenSi and its application in efficient removal of Ni(II) from aqueous solution

In this work, nano ferrite spinel NiFe2O4 was synthesized by sol-gel method and characterized by SEM, XRD, FT-IR, and VSM. In second step Schiff base made from salicylaldehyde and amino propyl triethoxy silane was used for modification of the synthesized nano ferrit. In the third step removal of Ni(II) was done using modified adsorbent and 95% efficiency was achieved. The removal rate was determined by atomic absorption spectroscopy. These studies showed that the Freundlich isotherm model was fitted well with adsorption data. Moreover, the pseudo-second order kinetic model was fitted very well with experimental data. The results demonstrated that NiFe2O4@SalenSi nanoadsorbent can be used for the removal and recovery of metal ions from wastewater over a number of cycles, indicating its suitability for the design of a continuous process.               KEY WORDS: Nano ferrite, Sol-gel method, Schiff base, Removal of Ni(II), Magnetic nanocomposite Bull. Chem. Soc. Ethiop. 2018, 32(1), 77-88DOI: https://dx.doi.org/10.4314/bcse.v32i1.

Intravenous valproate versus subcutaneous sumatriptan in acute migraine attack

Migraine is a common and incapacitating neurologic disorder manifesting with episodic moderate to a severe headache and other symptoms such as photophobia, phonophobia, nausea, and vomiting. Triptans and ergot compounds have been used as treatment options for an acute migraine headache for many years. Triptans are considered the first line of treatment in patients with moderate to a severe migraine. Although the triptans are commonly used at any time during a migraine attack; they are more efficacious when used in the early stages of a migraine. Intravenous valproic acid has been shown to be well tolerated, safe, and with rapid onset of action in patients with acute moderate to severe and even refractory migraine. Sodium valproate is a Food and Drug Administration (FDA)�approved drug for prophylaxis of a migraine with and without aura. In this study, the main goal was to compare the effectiveness of sumatriptan versus valproate in an acute migraine. A randomized clinical trial including 37 patients with an acute migraine was considered to compare the effectiveness of sumatriptan versus valproate. The patients were divided into two groups. In first group, 6 mg subcutaneous of sumatriptan and in the second group 15 mg/Kg of valproate was administered. The outcomes including pain and drug adverse effects were compared across the groups. A total of 37 patients (7 male and 30 female) were evaluated in two groups. The difference between two groups regarding sex and age was not significant (P>0.05). The mean pain scores reduced from 8.3 to 4.7 and from 8.3 to 2.2 after one hour of treatment in sumatriptan and valproate groups, respectively. Response to treatment in valproate group was faster and more effective than sumatriptan group (P<0.05).The results indicated that valproate was more effective and with the faster response in patients with an acute migraine in comparison with sumatriptan without any recurrence and remarkable side effects. � 2015 Tehran University of Medical Sciences. All rights reserved

Analysis of Opportunities and Challenges for R&D Management and the Role of the R&D Society for its Improvement – A Case Study in Iran

Research and Development (R&D) management in Iran is faced to many barriers and obstacles, in which R&D units are considered as the basic core of the product development and innovation. Due to structural shortcomings, a great number of organizations and industries have not been able to find their actual status. There are about different 1141 R&D units with a dispersion pattern in Iran. This paper considers and analyzes the R&D case study in one of the provinces located in the north part of Iran in order to enhance the potential R&D activities in respect with the industrialized areas and zones. In this province, there are about 2504 industrial units of which there are only 44 R&D units certified by the state government. However, there are limit numbers of these R&D units that are extensively active. This paper also addresses the current status in respect with the R&D activities to find out why there is a lack and depression of these activities in the industrial units. By considering the opportunity and challenges of these R&D units, there is a need to change these units to be active in order to quickly respond the market and demand requirements. Finally, a few alternative solutions and improvement plans are proposed, in which the Iranian R&D Society is responsible for supporting and succeeding these action plans towards the organization goals.R&D Management

Synthesis and crystallographic characterization of new heterotrinuclear oxo-centered complex

New oxo-centered trinuclear mixed-metal complex, of [Fe2ZnO(CHCl2CO2)6(CHCl2CO2)3].NO3 was synthesized by the direct reaction between metal nitrates and dichloroacetic acid. These compounds have a typical μ3-oxo trinuclear structure: (a) three metal atoms are situated in the apexes of the equilateral triangle; (b) μ3-oxygen atom and six dichloroacetate ligands fulfil the bridge functions and (c) the monodentate CHCl2CO2 ligands complete the octahedral geometry of the metal ions. This complex were characterized by elemental analyses (CHN), atomic absorption spectroscopy and spectral (IR, electronic) studies. This is new types of oxo-bridged mixed-metal complex in which the carboxylate ligand is dichloroacetic acid. The UV spectra of the complex exhibited strong bands in the region 213 and 257 nm which are related to the (π → π*) and (n → π*) transitions of the CHCl2CO2 ligands, respectively. The IR spectra of this compound showed two strong stretching vibrations bands, indicating a bridging coordination mode of the carboxylic group by presence of νasym (M2M'O) vibrations of the ligand in the infrared spectra.               KEY WORDS: Oxo-centered, Trinuclear complexes, Carboxylic ligand, Crystallographic data, IR spectra Bull. Chem. Soc. Ethiop. 2018, 32(3), 491-500.DOI: https://dx.doi.org/10.4314/bcse.v32i3.

Evaluating high risks in large-scale projects using an extended VIKOR method under a fuzzy environment

The complexity of large-scale projects has led to numerous risks in their life cycle. This paper presents a new risk evaluation approach in order to rank the high risks in large-scale projects and improve the performance of these projects. It is based on the fuzzy set theory that is an effective tool to handle uncertainty. It is also based on an extended VIKOR method that is one of the well-known multiple criteria decision-making (MCDM) methods. The proposed decision-making approach integrates knowledge and experience acquired from professional experts, since they perform the risk identification and also the subjective judgments of the performance rating for high risks in terms of conflicting criteria, including probability, impact, quickness of reaction toward risk, event measure quantity and event capability criteria. The most notable difference of the proposed VIKOR method with its traditional version is just the use of fuzzy decision-matrix data to calculate the ranking index without the need to ask the experts. Finally, the proposed approach is illustrated with a real-case study in an Iranian power plant project, and the associated results are compared with two well-known decision-making methods under a fuzzy environment

Microwave-promoted solvent free one-pot synthesis of triazolo[1,2-a] indazole-triones catalyzed by silica-supported La0.5Ca 0.5CrO3 nanoparticles as a new and reusable perovskite-type oxide

Microwave assisted solvent free synthesis of triazolo[1,2-a]indazole-1,3,8-triones through one-pot three-component reaction of dimedone, phenyl urazole and aromatic aldehydes is presented. The reaction process was catalyzed by La0.5Ca0.5CrO3 and silica-supported La0.5Ca0.5CrO3 nanoparticles as new perovskite-type catalysts. The nano catalyst was studied by XRD, SEM and IR characterization tools. Some advantages of the proposed approach include high yield, being eco-friendly, procedure convenience and reusability of the catalyst.               KEY WORDS: One-pot reaction, Triazolo[1,2-a]indazole trione, Perovskite oxide, Nano catalyst, Microwave, Solvent-free Bull. Chem. Soc. Ethiop. 2018, 32(2), 239-248.DOI: https://dx.doi.org/10.4314/bcse.v32i2.

STR-944: EFFECTS OF FINITE ELEMENT MODELLING APPROACH FOR PRESTRESSING SYSTEM ON THE PRESSURE CAPACITY OF A CANDU CONTAINMENT STRUCTURE

The primary objective of this article is to investigate the response of a CANDU®1 nuclear power plant containment structure to a much higher internal pressure that could be encountered during a severe accident. In this study, for the prestressed containment structure, a detailed model is obtained by a full 3D model. Nonlinear finite element method is employed to predict the response of the structure using ANSYS software. The major challenges for modelling prestressing tendon elements are to accommodate parameters affecting prestressing forces. In previous research studies, the prestressing system is modelled using an equivalent pressure and tendon end forces, and tendons are modelled as smeared reinforcement in the concrete elements. In this study, the prestressing tendons are modelled using discrete elements. This method enables the capability of the model to update the prestressing forces accommodating the non-uniform losses. The difference in the response of the structure using the discrete model for the prestressing tendons and the smeared approach is 15 percent. It is observed that the containment structure, meets the design requirements of the current standards as it behaves linearly up to 1.5 times the design pressure, and the ultimate pressure capacity is estimated as 2.7 times the design pressure. The ultimate pressure capacity is reached when the prestressing tendon rupture at the dome

Lymphocele after kidney transplantation: where are we standing now?

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