Deformation behavior in the tubular channel angular pressing (TCAP) as a noble SPD method for cylindrical tubes

Faraji, G.,Mashhadi, M. M.,Abrinia, K.,Kim, H. S. Springer-Verlag 2012 Applied physics. A, Materials science & processing Vol.107 No.4

Numerical and experimental investigation of the deformation behavior during the accumulative back extrusion of an AZ91 magnesium alloy

Faraji, G.,Jafarzadeh, H.,Jeong, H.J.,Mashhadi, M.M.,Kim, H.S. BUTTERWORTH - HEINEMANN 2012 MATERIALS AND DESIGN Vol.35 No.-

<P><B>Highlights</B></P><P>► The accumulative back extrusion (ABE) was introduced as a high straining method suitable for AZ91. ► The strain distribution and deformation behavior during the ABE process using the finite element simulation was investigated. ► The deformation ratio and die stroke led to better deformation homogeneity and more plastic strains.</P> <P><B>Abstract</B></P><P>In the present study, the finite element method (FEM) and an experimental investigation were performed during the accumulative back extrusion (ABE) processing of an AZ91 magnesium alloy in order to investigate the effects of the deformation ratio (= inner punch diameter/outer punch diameter) and die stroke (DS) on the plastic deformation behavior. The results showed that increasing the deformation ratio and DS led to better deformation homogeneity and more plastic strains. There are two distinct regions in the ABE processed samples containing low and high plastic strain areas and the metallurgical investigations showed that more grain refinement with a mean grain size of 1.5μm takes place in high strain regions while the grain sizes are larger in other regions. A comparison between the FEM and experimental results of the required loads and developed microstructures showed good agreement.</P>

Two-dimensional materials in semiconductor photoelectrocatalytic systems for water splitting

Faraji, Monireh,Yousefi, Mahdieh,Yousefzadeh, Samira,Zirak, Mohammad,Naseri, Naimeh,Jeon, Tae Hwa,Choi, Wonyong,Moshfegh, Alireza Z. The Royal Society of Chemistry 2019 Energy & environmental science Vol.12 No.1

<P>Hydrogen (H2) production <I>via</I> solar water splitting is one of the most ideal strategies for providing sustainable fuel because this requires only water and sunlight. In achieving high-yield production of hydrogen as a recyclable energy carrier, the nanoscale design of semiconductor (SC) materials plays a pivotal role in both photoelectrochemical (PEC) and photocatalytic (PC) water splitting reactions. In this context, the advent of two-dimensional (2D) materials with remarkable electronic and optical characteristics has attracted great attention for their application to PEC/PC systems. The elaborate design of combined 2D layered materials interfaced with other SCs can markedly enhance the PEC/PC efficiencies <I>via</I> bandgap alteration and heterojunction formation. Three classes of 2D materials including graphene, transition metal dichalcogenides (TMDs), and graphitic carbon nitride (g-C3N4), and their main roles in the photoelectrocatalytic production of H2, are discussed in detail herein. We highlight the various roles of these 2D materials, such as enhanced light harvesting, suitable band edge alignment, facilitated charge separation, and stability during the water splitting reaction, in various SC/2D photoelectrode and photocatalytic systems. The roles of emerging 2D nanomaterials, such as 2D metal oxyhalides, 2D metal oxides, and layered double hydroxides, in PEC H2 production are also discussed.</P>

Deformation Behavior in Tubular Channel Angular Pressing (TCAP) Using Triangular and Semicircular Channels

Faraji, Ghader,Mashhadi, Mahmoud Mosavi,Kim, Hyoung Seop The Japan Institute of Metals 2012 MATERIALS TRANSACTIONS Vol.53 No.1

<P>In this paper, two different (triangular and semicircular) channel types were investigated in tubular channel angular pressing (TCAP) suitable for deforming cylindrical tubes to large strains without changing the tube dimensions. To examine the effects of the channel geometry on the strain distribution and deformation behavior during the TCAP process, finite element method (FEM) simulations and an analytical model were employed. The FEM results demonstrate that equivalent plastic strains of 2.15–2.9 and 2.35–2.6 were developed after applying one pass TCAP in the triangular and semicircular channels, respectively. The mean values of the equivalent plastic strains were almost identical for both cases, but the strain through the thickness with semicircular channel was more homogeneous than that in the triangular channel. Tube thinning in the early stages of the process was observed as a result of tensile circumferential strains, but this can be compensated by the back pressure effect resulting from the next shear zones and also compressive circumferential strain resulting from the decreasing tube diameter. While the strain values for both channel types were similar, the required load for the semicircular channel was lower than that of the triangular channel.</P>

Synthesis of Novel Chiral Diamino Alcohols and Their Application in Copper-Catalyzed Asymmetric Allylic Oxidation of Cycloolefins

Faraji, Laleh,Samadi, Saadi,Jadidi, Khosrow,Notash, Behrouz Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.7

The small library of new enantiomerically pure (S,S)-diamino alcohols 1 and their hydroxyldiamide precursors 2 were conveniently synthesized on a gram scale from inexpensive and commercially chiral pool amino acids. The catalytic and induced asymmetric effects of the chiral ligands 1 in the asymmetric allylic oxidation of cycloolefins were investigated.

Mechanistic Effects of Vitamin D Supplementation on Metabolic Syndrome Components in Patients with or without Vitamin D Deficiency

Samira Faraji,Mohammad Alizadeh 대한비만학회 2020 The Korean journal of obesity Vol.29 No.4

The prevalences of metabolic syndrome (MetS) and vitamin D deficiency are increasing dramatically worldwide. MetS is a major challenge because it can increase the risk of most non-communicable diseases. The beneficial effect of vitamin D on MetS components remains controversial, so the present review focused on the clinical effects of vitamin D supplementation on MetS components. Vitamin D can inhibit the protein expression of nuclear factor beta; improve arterial stiffness; decrease renin-angiotensin-aldosterone system activity, parathyroid hormone levels, inflammatory cytokines, 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and lanosterol 14 α-demethylase enzyme activity; increase the activity of lipoprotein lipase; alter gene expression in C2C12 cells; and improve phospholipid metabolism and mitochondrial oxidation. We tried to elucidate and analyze almost all evidence from randomized controlled trial studies of the efficacy of vitamin D supplementation in patients with MetS. The findings of the present study reported beneficial effects of vitamin D supplementation on mentioned factors. Vitamin D supplementation is recommended in people with vitamin D deficiency even if it has no considerable effect on most MetS factors. However, existing data from interventional studies are insufficient to reach a definitive conclusion about the effect of vitamin D supplementation on MetS components in patients without vitamin D deficiency. Thus, new clinical studies are needed to test the hypothesis that vitamin D supplementation could alleviate MetS components in patients with sufficient intake of vitamin D.

Synthesis of Novel Chiral Diamino Alcohols and Their Application in Copper-Catalyzed Asymmetric Allylic Oxidation of Cycloolefins

Laleh Faraji,Saadi Samadi,Khosrow Jadidi,Behrouz Notash 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.7

The small library of new enantiomerically pure (S,S)-diamino alcohols 1 and their hydroxyldiamide precursors 2 were conveniently synthesized on a gram scale from inexpensive and commercially chiral pool amino acids. The catalytic and induced asymmetric effects of the chiral ligands 1 in the asymmetric allylic oxidation of cycloolefins were investigated.

Fluid heating in a nano-scale Poiseuille flow: A non-equilibrium molecular dynamics study

Fahim Faraji,Ali Rajabpour 한국물리학회 2017 Current Applied Physics Vol.17 No.12

In this paper we develop a non-equilibrium molecular dynamics computer simulation to study the fluid heating in a nano scale Poiseuille flow system and discuss the effects of the fluid-wall interaction strength and wall temperature on the fluid heating. We calculate the fluid temperature distribution, as well as the heat flux from the fluid towards the walls and the interfacial thermal resistance and discuss the variations of the fluid heating caused by the viscous and surface frictions as the fluid-wall interaction strength and wall temperature vary. It is found that as the fluid-wall interactions strengthen, the fluid heating diminishes. In weak interactions, the heat flux from the fluid to the wall is almost independent of the wall temperature while the interfacial thermal resistance decreases with increased wall temperature and the surface friction is the major contribution to the fluid heating; in contrast, in large interactions, both the heat flux and thermal resistance increase with increased wall temperature and the viscous friction is the major contribution to the fluid heating.

A numerical and experimental study on tubular channel angular pressing (TCAP) process

G. Faraji,M. M. Mashhadi,A. F. Dizadji,M. Hamdi 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.11

Tubular channel angular pressing (TCAP) is a new and novel severe plastic deformation (SPD) technique suitable for fabrication of bulk nanograined tubular materials. There are several parameters in the TCAP process. The present paper investigates the effects of curvature angles, deformation ratio (maximum radius during TCAP/initial radius) and deformation direction on the plastic deformation behavior,strain homogeneity and required loads in TCAP processing. The results showed that higher curvature angles (ψ1 and ψ3) leads to better strain homogeneity while have not having any significant effect on the process loads. Also, at the second curvature angle of 90°,the best condition is achieved with good strain homogeneity and lower load requirements rather than lower angles. Investigation of deformation direction showed that inlet deformation direction causes tube thinning at the end of the process, and thus, using the inlet case is not recommended.

Enhanced CO2 removal in hollow fiber membrane contactors using amine-based nanofluids

Saman Faraji Gargari,Seyed Mojtaba Mirfendereski 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Increasing the mass transfer coefficient, improving the rheological properties of the liquid, reducing thepossibility of wetting, and reducing the consumption of the absorbent are among the significant effects ofusing nanofluids in membrane contactors as chemical absorbents. The use of nanofluids allows the systemto use higher transmembrane pressures and higher liquid flow rates. In this work, stable aminebasednanofluid were prepared by adding different amounts (0–0.4 wt%) of three nanoparticles (Al2O3,Fe3O4, and MWCNT-COOH) to MEA aqueous solution. Amine-based nanofluids were then used in a membranecontactor to remove CO2 from the gas mixtures. The influence of effective parameters on the separationperformance was evaluated in order to better understand how NPs affect CO2 removal. Thefindings of this work show that the use of nanofluids can improve CO2 removal performance by 5%and thus reduce adsorbent consumption by 20%. The effect of nanoparticle dispersion on mass transferflux was evaluated using a new enhancement factor (Rnano). Numerical methods were used to providea suitable equation for Rnano so that it can be combined with general mass transfer equations. TheRnano values obtained for the NPs used in this work were in the range of 0.03–0.05.