Zinc (II) [tetra(4-methylphenyl)] Porphyrin: a Novel and Reusable Catalyst for Efficient Synthesis of 2,4,5-trisubstituted Imidazoles Under Ultrasound Irradiation

Safari, Javad,Khalili, Shiva Dehghan,Banitaba, Sayed Hossein,Dehghani, Hossein Korean Chemical Society 2011 대한화학회지 Vol.55 No.5

An efficient three-component one-step synthesis of 2,4,5-trisubstituted imidazoles by condensation reaction of 1,2-diketones or ${\alpha}$-hydroxyketones with aromatic aldehydes and ammonium acetate using Zinc (II) [tetra (4-methylphenyl)] porphyrin as a novel and reusable catalyst under ultrasound irradiation at ambient temperature is described. In this method, ${\alpha}$-hydroxyketones as well as 1,2-diketones were converted to their corresponding 2,4,5-trisubstituted imidazoles in excellent yields.

Free vibration of electro-magneto-thermo sandwich Timoshenko beam made of porous core and GPLRC

Safari, Mohammad,Mohammadimehr, Mehdi,Ashrafi, Hossein Techno-Press 2021 Advances in nano research Vol.10 No.2

In this article, free vibration behavior of electro-magneto-thermo sandwich Timoshenko beam made of porous core and Graphene Platelet Reinforced Composite (GPLRC) in a thermal environment is investigated. The governing equations of motion are derived by using the modified strain gradient theory for micro structures and Hamilton's principle. The magneto electro are under linear function along the thickness that contains magnetic and electric constant potentials and a cosine function. The effects of material length scale parameters, temperature change, various distributions of porous, different distributions of graphene platelets and thickness ratio on the natural frequency of Timoshenko beam are analyzed. The results show that an increase in aspect ratio, the temperature change, and the thickness of GPL leads to reduce the natural frequency; while vice versa for porous coefficient, volume fractions and length of GPL. Moreover, the effect of different size-dependent theories such as CT, MCST and MSGT on the natural frequency is investigated. It reveals that MSGT and CT have most and lowest values of natural frequency, respectively, because MSGT leads to increase the stiffness of micro Timoshenko sandwich beam by considering three material length scale parameters. It is seen that by increasing porosity coefficient, the natural frequency increases because both stiffness and mass matrices decreases, but the effect of reduction of mass matrix is more than stiffness matrix. Considering the piezo magneto-electric layers lead to enhance the stiffness of a micro beam, thus the natural frequency increases. It can be seen that with increasing of the value of WGPL, the stiffness of microbeam increases. As a result, the value of natural frequency enhances. It is shown that in hc/h = 0.7, the natural frequency for WGPL = 0.05 is 8% and 14% less than its for WGPL = 0.06 and WGPL = 0.07, respectively. The results show that with an increment in the length and width of GPLs, the natural frequency increases because the stiffness of micro structures enhances and vice versa for thickness of GPLs. It can be seen that the natural frequency for aGPL = 25 ㎛ and hc/h = 0.6 is 0.3% and 1% more than the one for aGPL = 5 ㎛ and aGPL = 1 ㎛, respectively.

The Effects of Air Pollution on Ischemic Stroke Admission Rate

Hossein Alimohammadi,Sara Fakhri,Hojjat Derakhshanfar,Seyed-Mostafa Hosseini-Zijoud,Saeed Safari,Hamid Reza Hatamabadi 전남대학교 의과학연구소 2016 전남의대학술지 Vol.52 No.1

The present study aimed to determine the relationship between the level of air pollutantsand the rate of ischemic stroke (IS) admissions to hospitals. In this retrospectivecross-sectional study, stroke admissions (January-March 2012 and 2013) to an emergencydepartment and air pollution and meteorological data were gathered. The relationshipbetween air pollutant levels and hospital admission rates were evaluated usingthe generalize additive model. In all 379 patients with IS were referred to the hospital(52.5% male; mean age 68.2±13.3 years). Both transient (p<0.001) and long-term(p<0.001) rises in CO level increases the risk of IS. Increased weekly (p<0.001) andmonthly (p<0.001) average O3 levels amplifies this risk, while a transient increase inNO2 (p<0.001) and SO2 (p<0.001) levels has the same effect. Long-term changes inPM10 (p<0.001) and PM2.5 (p<0.001) also increase the risk of IS. The findings showedthat the level of air pollutants directly correlates with the number of stroke admissionsto the emergency department.

Forced vibration of a sandwich Timoshenko beam made of GPLRC and porous core

Mohammad Safari,Mehdi Mohammadimehr,Hossein Ashrafi 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.88 No.1

In this study, forced vibration behavior of a piezo magneto electric sandwich Timoshenko beam is investigated. It is assumed a sandwich beam with porous core and graphene platelet reinforced composite (GPLRC) in facesheets subjected to magneto-electro-elastic and temperature-dependent material properties. The magneto electro platelets are under linear function along with the thickness that includes a cosine function and magnetic and electric constant potentials. The governing equations of motion are derived using modified strain gradient theory for microstructures. The effects of material length scale parameters, temperature change, different distributions of porous, various patterns of graphene platelets, and the core to face sheets thickness ratio on the natural frequency and excited frequency of a sandwich Timoshenko beam are scrutinized. Various size-dependent methods effects such as MSGT, MCST, and CT on the natural frequency is considered. Moreover, the final results affirm that the increase in porosity coefficient and volume fractions lead to an increase in the amount of natural frequency; while vice versa for the increment in the aspect ratio. From forced vibration analysis, it is understood that by increasing the values of volume fraction and the length thickness of GPL, the maximum deflection of a sandwich beam decreases. Also, it is concluded that increasing the temperature, the thickness of GPL, and the initial force leads to a decrease in the maximum deflection of GPL. It is also shown that resonance phenomenon occurs when the natural and excitation frequencies become equal to each other. Outcomes also reveal that the third natural frequency owns the minimum value of both deflection and frequency ratio and the first natural frequency has the maximum.

Health-Related Quality of Life and its Associated Factors in COVID-19 Patients

Arab-Zozani Morteza,Hashemi Fatemah,Safari Hossein,Yousefi Mahmood,Ameri Hosein 질병관리본부 2020 Osong Public Health and Research Persptectives Vol.11 No.5

Objectives Health-related quality of life (HRQoL) is one of the most important outcome measures for patients. The purpose of this study was to evaluate HRQoL and related factors in Coronavirus disease 2019 (COVID-19) patients. Methods A total of 420 COVID-19 patients who had been discharged from hospital were selected using a systematic sampling. The EuroQol 5-dimensional-5 levels (EQ-5D-5L) questionnaire along with medical records of the patients were used to gather the data. The t test and analysis of variance were employed to test the difference between mean EQ-5D-5L scores, and the BetaMix model was used to investigate factors associated with EQ-5D-5L scores. Results The mean score for the patients who completed the EQ-5D-5L questionnaire (n = 409) was 0.6125. The EQ-5D-5L scores were significantly higher in males, patients with younger age, those with a low level of education, the employed, patients who worked in uncrowded workplaces, patients without diabetes, and those who were not admitted to intensive care unit. The BetaMix model showed that gender, age, education, employment status, having diabetes, heart failure, and admission to the intensive care unit were significant independent predictors of the EQ-5D-5L index values. Conclusion The mean score for EQ-5D-5L in COVID-19 patients was low in this study. Some of the factors, especially aging and having diabetes, should be considered in the aftercare of patients to improve their HRQoL.

A computational intelligence scheme for prediction of interfacial tension between pure hydrocarbons and water

Kalantari Meybodi, Mahdi,Shokrollahi, Amin,Safari, Hossein,Lee, Moonyong,Bahadori, Alireza Elsevier 2015 Chemical engineering research & design Vol.95 No.-

<P><B>Abstract</B></P> <P>Interfacial tension plays a major role in many disciplines of science and engineering. Complex nature of this property has restricted most of the previous theoretical studies on thermophysical properties to bulk properties measured far from the interface. Considering the drawbacks and deficiencies of preexisting models, there is yet a huge interest in accurate determination of this property using a rather simple and more comprehensive modeling approach. In recent years, inductive machine learning algorithms have widely been applied in solving a variety of engineering problems. This study introduces least-square support vector machines (LS-SVM) approach as a viable and powerful tool for predicting the interfacial tension between pure hydrocarbon and water. Comparing the model to experimental data, an excellent agreement was observed yielding the overall squared correlation coefficient (<I>R</I> <SUP>2</SUP>) of 0.993. Proposed model was also found to outperform when compared to some previously presented multiple regression models. An outlier detection method was also introduced to determine the model applicability domain and diagnose the outliers in the gathered dataset. Results of this study indicate that the model can be applied in systems over temperature ranges of 454.40–890°R and pressure ranges of 0.1–300MPa.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Least square support vector machine (LS-SVM) algorithm is used to estimate Interfacial tension (IFT). </LI> <LI> The model has been developed and tested using several hundreds series of the data. </LI> <LI> Validity of the presented models has been evaluated by utilizing several statistical parameters. </LI> <LI> The predictions of the developed models results are in excellent agreement with data. </LI> </UL> </P>