Showing papers by "Bu-Ali Sina University published in 2015"
TL;DR: There is sufficient evidence that AUD significantly increases the risk of suicidal ideation, suicide attempt, and completed suicide, and AUD can be considered an important predictor of suicide and a great source of premature death.
Abstract: BACKGROUND: Several original studies have investigated the effect of alcohol use disorder (AUD) on suicidal thought and behavior, but there are serious discrepancies across the studies. Thus, a systematic assessment of the association between AUD and suicide is required. METHODS: We searched PubMed, Web of Science, and Scopus until February 2015. We also searched the Psycinfo web site and journals and contacted authors. We included observational (cohort, case-control, and cross-sectional) studies addressing the association between AUD and suicide. The exposure of interest was AUD. The primary outcomes were suicidal ideation, suicide attempt, and completed suicide. We assessed heterogeneity using Q-test and I2 statistic. We explored publication bias using the Egger's and Begg's tests and funnel plot. We meta-analyzed the data with the random-effects models. For each outcome we calculated the overall odds ratio (OR) or risk ratio (RR) with 95% confidence intervals (CI). RESULTS: We included 31 out of 8548 retrieved studies, with 420,732 participants. There was a significant association between AUD and suicidal ideation (OR=1.86; 95% CI: 1.38, 2.35), suicide attempt (OR=3.13; 95% CI: 2.45, 3.81); and completed suicide (OR=2.59; 95% CI: 1.95, 3.23 and RR=1.74; 95% CI: 1.26, 2.21). There was a significant heterogeneity among the studies, but little concern to the presence of publication bias. CONCLUSIONS: There is sufficient evidence that AUD significantly increases the risk of suicidal ideation, suicide attempt, and completed suicide. Therefore, AUD can be considered an important predictor of suicide and a great source of premature death. Language: en
327 citations
TL;DR: In this article, the authors investigated thermal radiation in a semi annulus enclosure with Ferrohydrodynamic and magnetohydrodynamic (MHD) flow and heat transfer and showed that Nusselt number is an increasing function of Rayleigh number, nanoparticle volume fraction, magnetic number while it is a decreasing function of with Hartmann number and radiation parameter.
Abstract: In this paper, ferrofluid flow and heat transfer in a semi annulus enclosure is investigated considering thermal radiation. The enclosure has a wall with constant heat flux boundary condition. Combined effects of Ferrohydrodynamic (FHD) and magnetohydrodynamic (MHD) are considered. It is assumed that the magnetization of the fluid is varying linearly with temperature and magnetic field intensity. Control Volume based Finite Element Method (CVFEM) is applied to solve the governing equations. The calculations were performed for different governing parameters namely; the Radiation parameter, Rayleigh number, nanoparticle volume fraction, Magnetic number arising from FHD and Hartmann number arising from MHD. Results show that Nusselt number is an increasing function of Rayleigh number, nanoparticle volume fraction, magnetic number while it is a decreasing function of with Hartmann number and radiation parameter.
218 citations
TL;DR: In this article, a microstructure analysis revealed that modification of the interfacial transition zone (ITZ) was responsible for this strength enhancement, and the results demonstrated that adding 3% or 5% nS to specimens free of silica fume would increase both cement paste and concrete compression strength.
198 citations
TL;DR: In this article, polyaniline/reduced graphene oxide/Au nano particles (PANI/rGO/auNPs) were used as a hybrid supercapacitor for electrochemical redox capacitors.
185 citations
TL;DR: In this article, the boundary layer forms of the governing partial differential equations (momentum and energy equations) are transformed into highly nonlinear coupled ordinary differential equations, which are solved numerically using a fourth order Runge-Kutta method based shooting technique.
175 citations
TL;DR: In this article, a new application of multi objective particle swarm optimization (MOPSO) with the aim of determining optimal location and size of distributed generations (DGs) and shunt capacitor banks (SCBs) simultaneously with considering load uncertainty in distribution systems is proposed.
167 citations
TL;DR: The proposed method is simple and low cost for the manufacture of highly oleophilic and highly hydrophobic sponges, which can be successfully used for effective oil-spill cleanup and water filtration.
Abstract: A highly hydrophobic and highly oleophilic sponge was synthesized by simple vapor-phase deposition followed by polymerization of polypyrrole followed by modification with palmitic acid. The prepared sponge shows high absorption capacity in the field of separation and removal of different oil spills from water surface and was able to emulsify oil/water mixtures. The sponge can be compressed repeatedly without collapsing. Therefore, absorbed oils can be readily collected by simple mechanical squeezing of the sponge. The prepared hydrophobic sponge can collect oil from water in both static and turbulent conditions. The proposed method is simple and low cost for the manufacture of highly oleophilic and highly hydrophobic sponges, which can be successfully used for effective oil-spill cleanup and water filtration.
163 citations
TL;DR: In this paper, the authors studied the fatigue behavior of Alvand monzogranite and found that the maximum stress level and frequency influenced fatigue behavior more than amplitude, and that fatigue life increased with increasing frequency and decreasing maximum stress levels.
150 citations
TL;DR: In this article, the effects of freeze-thaw, wet-dry, and heat-cool cycles on the physical and mechanical properties of Upper Red Formation sandstones located southwest of Qom, central Iran, were determined.
Abstract: The effects of wet–dry,
freeze–thaw, and heat–cool cycles on the physical and mechanical properties of Upper Red Formation sandstones located southwest of Qom, central Iran, were determined. Five different types of sandstones were selected, and freeze–thaw, wet–dry, and heat–cool cyclic tests were performed. The freeze–thaw test was carried out for 30 cycles, and the P-wave velocities, porosities, and uniaxial compressive strengths of the specimens were determined after every five cycles. Heat–cool and wet–dry cycles were repeated for 40 cycles. Based on the strength deterioration ratio, it was found that freeze–thaw cycles degrade the physical and mechanical properties of sandstones more strongly than heat–cool and wet–dry cycles do. The results also show that the presence of zeolite cement has a significantly effect on sandstone resistance to freeze–thaw cycles. Further, it was found that sandstone strength as well as petrographic properties such as grain size and grain contacts do not have the expected effect on sample deterioration during freeze–thaw cycles. Finally, it was concluded that pore size plays an important role in sandstone resistance to freeze–thaw cycles.
148 citations
TL;DR: In this article, the electrochemical behavior of coarse-grained and finegrained AISI 430 ferritic stainless steel in 0.1 M HNO 3 solution was investigated.
146 citations
TL;DR: In this article, the authors evaluated the weathering behaviors of nine sandstones from the Qazvin area (western Iran) and found that the thermal behavior of sandstones under wet and dry conditions were different.
Abstract: Rocks are used in engineering works as monuments, building stones, and architectural covering stones. Their weathering behaviors and physical and mechanical properties are the most important factors controlling their suitability as building stones. The aim of this study is to evaluate the weathering behaviors of sandstones from the Qazvin area (western Iran). In total, nine sandstones (A, B, C, CG, S, S1, Min, Tr, and Sh) were analyzed. Accelerated weathering processes, namely freezing–thawing (F–T), salt crystallization (SC), heating–cooling (H–C), and heating–cooling–wetting (H–C–W), were used. Sandstones were subjected to 60 cycles of F–T, H–C, and H–C–W and 20 cycles of SC, and changes in characteristics including weight loss (%), P-wave velocity loss (%), and changes in uniaxial compressive strength (UCS) and point load strength were recorded after different numbers of cycles. The results from our laboratory studies indicate that rocks from the same stratigraphic layer can show major differences in weathering properties, and their sensitivity to these processes are different. Also, it was found that the thermal behavior of sandstones under wet and dry conditions were different. In the next stage of this study, a decay function model was used to statistically evaluate the disintegration rate. This model showed that the disintegration rate was higher for salt recrystallization compared with F–T, H–C, and H–C–W processes.
TL;DR: An electrochemical sensor fabricated using graphene, 1-n-octylpyridinum hexafluorophosphate, and [2,4-Cl2C6H3C(O)CHPPh3] (L), as a new synthetic phosphorus ylide is described and applied to detect trace analyte ions in various water and soil samples with satisfactory results.
TL;DR: In this article, a nanoporous metal organic framework (MOF-5) was synthesized as the copper ion (Cu 2 + ) adsorbent, which was characterized by XRD, SEM and nitrogen adsorption/desorption methods.
TL;DR: The proposed framework can be considered as an efficient tool in planning and energy management of MGs through optimizing the type and capacity of distributed generation sources as well as the capacity of storage devices.
Abstract: Recently, microgrids (MGs) have attracted considerable attention as a high-quality and reliable source of electricity. In this paper, energy management in MGs is addressed in the light of economic efficiency, environmental restrictions, and reliability improvement via: 1) optimizing the type and capacity of distributed generation (DG) sources, as well as the capacity of storage devices (SD); and 2) developing an operational strategy (OS) for energy management in MGs. A master-slave objective function based on net present value (as an economic indicator) is proposed. Such objective function is solved using a hybrid optimization method. This method includes two steps. In the first step, 2-D slave object functions (SOFs), operating costs, and consumer outage cost (as a reliability index) are minimized by quadratic programming and particle swarm optimization (PSO) algorithms, respectively. Then Pareto curve is drawn for SOF and fuzzy logic is employed to select the best SOF solution, OS, from Pareto curve. In the second step, using the best OS from step one for any iteration, PSO algorithms employed to solve master objective function, and to determine the optimum capacity and type of DGs and SDs. The results show that the proposed framework can be considered as an efficient tool in planning and energy management of MGs.
TL;DR: In this article, a new method for evaluating the effect of integrating a large number of EVs on a power system and their impact on the network voltage profile via injecting reactive power into highly loaded buses is proposed.
TL;DR: In this article, residues of sunflower, potato, canola, and walnut shell were used as sorbents to sorb heavy metals from aqueous solutions using batch experiments.
Abstract: In this research, the residues of sunflower, potato, canola, and walnut shell were used as sorbents to sorb heavy metals (Fe, Mn, Zn, Ni, Cu, and Cd) from aqueous solutions using batch experiments. The effect of pH and contact time was investigated. Maximum sorption of heavy metals by different sorbents was observed around pH 4–8. The optimal contact time was in the range of 20–600 min. The values of pHzpc (zero point of charge) measured for sunflower, potato, canola, and walnut shell residues were 6.06, 6.80, 6.15 and 5.85, respectively. The plant residues showed considerable capacity for removal of Fe, Mn, Zn, Cu, and Cd from aqueous solution but Ni sorption by residues was negligible. Chemical activation of sorbents with NaOH enhanced Ni sorption. Competitive sorption decreased the removal of heavy metals compared to the single system. The Langmuir isotherm model fitted well to experimental metals sorption. The sorption kinetic of heavy metals was described well by pseudo second order model. In our study, the sorption mechanisms such as electrostatic attraction and ion exchange as well as complexation seem to be the most occurring phenomena.
TL;DR: A sinkhole susceptibility model was produced in a GIS environment applying the analytical hierarchy process (AHP) approach and considering a selection of eight factors, each categorized into five classes: distance to faults (DF), water level decline (WLD), groundwater exploitation (GE), penetration of deep wells into karst bedrock (PKA), distance to deep wells (DDW), groundwater alkalinity (GA), bedrock lithology (BL), and alluvium thickness (AT). Relative weights were preliminarily assigned to each factor and to their different classes through systematic pairwise comparisons based on
TL;DR: In this article, the first order shear deformation theory considering the von Karman's nonlinear strains is used to obtain the equations of motion, whereas Maxwell equations for electrostatics and magnetostatics are used to model the electric and magnetic behavior.
TL;DR: In this article, a simple and eco-friendly procedure was devised for the green synthesis of palladium nanoparticles, using the aqueous extract of herbal tea (Stachys lavandulifolia), a renewable and nontoxic natural phyto-exudate.
Abstract: A simple and eco-friendly procedure has been devised for the green synthesis of palladium nanoparticles, using the aqueous extract of herbal tea (Stachys lavandulifolia), a renewable and nontoxic natural phyto-exudate. The water-soluble components of the extract act as reducing agent and stabilizer. This green route does not require a surfactant or capping agent for the growth of palladium nanoparticles. The generated nanoparticles were analysed using UV–visible spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis and inductively coupled plasma. The palladium nanoparticles having spherical shape and dimensions of between 5 and 7 nm were employed as a homogeneous catalyst for Suzuki coupling reactions conducted in water under mild conditions. Good yields of products, a facile work-up, no evidence of leached palladium from the catalyst surface and smooth recovery of the catalysis by adding ethyl acetate, which could be reused at least eight times, confirm the very good efficiency of the catalytic reaction. Copyright © 2014 John Wiley & Sons, Ltd.
11 Feb 2015-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the microstructure and room temperature mechanical properties of pure magnesium and cast AZ80 nano-composites were examined and the compressive stress-strain curves were also employed to study the work hardening behavior of the materials.
Abstract: The present work deals with the microstructure and room temperature mechanical properties of pure magnesium and cast AZ80 nano-composites. Toward this end, different weight percent of SiC reinforcement nano-particles (1.5, 2.5 and 3.5) were added homogenously into the matrix employing stir casting method. It was found that the SiC nano-particles can reduce the grain size of magnesium matrices, significantly. The presence of nano-particles assisted in improving the hardness values. In addition, the tensile strength and the ductility values increased by increasing the SiC content. This was reasoned considering the occurrence of grain refinement, Orowan strengthening, coefficient thermal expansion mismatch of the matrix-particles, and the load bearing effect. However, there was an optimum SiC content beyond which the strength and formability of the materials were decreased. The latter was attributed to the agglomeration of SiC particles in the microstructure of the composites. In line to these findings, the compression tests results also indicated continuous improvement of ultimate compressive strength. The compressive stress-strain curves were also employed to study the work hardening behavior of the materials.
TL;DR: An analytical formulation combined with a fractional-order time derivative damping model has been developed to conduct a comprehensive study on the large amplitude free and forced vibration response of carbon nanotubes (CNTs)/fiber/polymer laminated multiscale composite beams as mentioned in this paper.
TL;DR: The suggested potentiometric silver(I) sensor was successfully applied to the determination of silver in radiological film, environmental and drug samples with satisfactory results.
TL;DR: In this article, a carbon paste sensor composed of nanomaterials (graphene nanosheets and alumina nanoparticles), an Hg2+-ion imprinted polymer, as a sensing modifier, and an ionic liquid, as the binder, was prepared and used for the potentiometric determination of Hg 2+ ions in a wide variety of real samples.
TL;DR: In this article, the efficiency of the obtained MOF-derived nanoporous carbon (MOF-NC) particles as adsorbent for the removal of copper (Cu) ions from an aqueous solution was studied from both kinetic and equilibrium point of view.
TL;DR: Magnetic core-shell titanium dioxide nanoparticles (Fe3O4@SiO2@TiO2) were efficiently used for the preparation of tetrahydrobenzo[b]pyran derivatives via a one-pot three component condensation reaction of various aldehydes, dimedone and malononitrile at 100 °C under solvent-free conditions as discussed by the authors.
Abstract: Magnetic core–shell titanium dioxide nanoparticles (Fe3O4@SiO2@TiO2) were efficiently used for the preparation of tetrahydrobenzo[b]pyran derivatives via a one-pot three component condensation reaction of various aldehydes, dimedone and malononitrile at 100 °C under solvent-free conditions. The catalyst was synthesized and characterized by several techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX).
TL;DR: In this article, an electrochemical sensor was developed for detecting melatonin and dopamine using graphene (Gr) decorated with Fe3O4 magnetic nanoparticles on a carbon paste electrode (CPE).
Abstract: An electrochemical sensor was developed for melatonin and dopamine detection using graphene (Gr) decorated with Fe3O4 magnetic nanoparticles on a carbon paste electrode (CPE). The structure of the synthesized nanocomposites and the electrode composition were confirmed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Electrochemical studies revealed that modification of the electrode surface with Gr/Fe3O4 nanocomposite significantly increases the oxidation peak currents but reduces the peak potentials of melatonin and dopamine. The peak currents in square wave voltammetry of melatonin and dopamine increased linearly with their concentration in the range of 0.02–5.80 μM. The limits of detection (3sb/m) were found to be 8.40 × 10−3 and 6.50 × 10−3 μM for melatonin and dopamine, respectively. Also the effect of some interfering compounds, such as glucose, ascorbic acid, pyridoxine, serotonin, uric acid and others, on the determination of melatonin and dopamine was studied, and none of them had a significant effect on the assay recovery. Moreover, its practical applicability was reliable, which is desirable for analysis of biological fluids and pharmaceutical samples.
TL;DR: In this article, the influence of freeze-thaw cycles on physical and mechanical properties of Upper Red Formation sandstones in the southwestern Qom province in central Iran has been investigated for 30 cycles and P wave velocity, porosity and uniaxial compressive strength of specimens were determined after every 5 cycles.
Abstract: This paper presents the influence of freeze–thaw cycles on physical and mechanical properties of Upper Red Formation sandstones in the southwestern Qom province in central Iran. For this purpose, five different types of sandstones were selected. Freeze–thaw test was carried out for 30 cycles and P wave velocity, porosity and uniaxial compressive strength of specimens were determined after every 5 cycles. Also, long-term durability of sandstones against freeze–thaw cycles using a decay function model was evaluated. The results of this study show that an increase in number of freeze–thaw cycles decreases uniaxial compressive strength and P wave velocity, whereas the effective porosity increases. The results obviously indicate that rock strength and petrographic properties such as grain size and contacts between grains alone does not provide enough information regarding sample durability against freeze–thaw cycles. Finally, it was found that pore size distribution plays the main role on the resistance of sandstones in freeze–thaw cycles.
TL;DR: In this paper, some mathematical methods are proposed including multiple linear regression, multiple nonlinear regression, and artificial neural networks (ANNs) to predict uniaxial compressive strength (UCS) and modulus of elasticity (E) for limestone rocks in terms of P wave velocity, density, and porosity.
Abstract: Geomechanical properties of rocks such as uniaxial compressive strength (UCS) and modulus of elasticity (E) have been essentially evaluated for rock engineering projects as well as dam sites. In this paper, in order to estimate the parameters, some mathematical methods are proposed including multiple linear regression, multiple nonlinear regression, and artificial neural networks (ANNs). These methods were employed to predict UCS and E for limestone rocks in terms of P wave velocity, density, and porosity. The data of 105 rock samples from two different dam sites (located in Asmari Formation, Karun 4, and Khersan 3 dams) were obtained and analyzed for developing predictive models. Comparison of the multiple linear and nonlinear regressions and ANNs results indicated that respective ANN models were more acceptable for predicting UCS and E than the others. Also, it observed that between multiple linear and nonlinear regressions, second case has more capability to predict UCS. It should be noted that there were no strong relationships between the predicted and measured E in the both multiple regressions.
TL;DR: In this paper, the synthesis and use of copper nanoparticles supported on reduced graphene oxide, as separable catalysts for N-arylation of phenylurea with aryl halides under ligand-free and microwave conditions.
Abstract: This paper reports on the synthesis and use of copper nanoparticles supported on reduced graphene oxide, as separable catalysts for N-arylation of phenylurea with aryl halides under ligand-free and microwave conditions. The catalyst can be recovered and reused several times without significant loss of its catalytic activity. Also, the structural and optical properties are studied. Experimental absorbance spectra are compared with results obtained from the Maxwell-Garnett theory (MGT).
TL;DR: In this paper, the feasibility of modified nano-alumina (Al-H, Al-W, and Al-C) for Cd2+, Cu2+, and Ni2+ removal from single and competitive aqueous solutions was evaluated.
Abstract: We prepared novel Al2O3 nanoparticles (NPs) modified with humic acid (Al-H), extractant of walnut shell (Al-W), and 1,5-diphenyl Carbazon (Al-C). The present study was conducted to evaluate the feasibility of modified nano-alumina (Al-H, Al-W, and Al-C) for Cd2+, Cu2+, and Ni2+ removal from single and competitive aqueous solutions. The nature and morphology of sorbents were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Scanning electron microscopy (SEM) analysis. The SEM results revealed that the three modified nanoparticles had larger size in comparison with bare nanoparticles and with an average diameter of around 61 nm. Batch adsorption studies were performed as a function of contact time, initial heavy metals concentration (isotherm), and pH. Heavy metals sorption kinetics was well fitted by pseudo-second-order kinetic model. The maximum uptake values (sum of 3 metals) in competitive component solutions were 92.0, 97.0, and 63.8 mg g−1, for Al-H, Al-W, and Al-C, respectively. The heavy metals sorption has been well explained using Langmuir isotherm model. SEM–EDX before and after metal sorption, and soil solution saturation indices showed that the main mechanism of sorption for Cd2+ and Ni2+ was adsorption, whereas for Cu2+ sorption was due to adsorption and precipitation. Thus, the new nanoparticles are favorable and useful for the removal of Cd2+, Cu2+ metal ions particularly, in single solutions and with Al-C NPs. The high adsorption capacity makes them good promising candidate materials for heavy metal ions removal from water samples.