Experimental investigation of nanofibrous poly(vinylidene fluoride) membranes for desalination through air gap membrane distillation process

Javad Karimi-Sabet,Mojtaba Shariaty-Niassar,Rasoul Moradi,Younes Amini 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.10

A comparative study was conducted to evaluate the performance of two membrane types of electrospun poly(vinylidene fluoride) (PVDF) and commercial ploytetrafluoroethylene (PTFE). The optimized needleless electrospinning technique was used to prepare PVDF membranes. Scanning electron microscopy (SEM), wettability tests, water flux, mechanical strength and liquid entry pressure (LEP) measurements were performed to evaluate the prepared membrane. Air gap membrane distillation (AGMD) experiments were carried out to investigate the salt rejection performance and the durability of membranes. The results show that our nanofibrous PVDF membrane presents higher water permeation flux (>20 kg/m2 h) compared to commonly used PTFE. In addition, the experimental data confirms that competitive salt rejection efficiency (>99.8%) was obtained in this new membrane.

Preventive effects of crocin on neuronal damages induced by D-galactose through AGEs and oxidative stress in human neuroblastoma cells (SH-SY5Y)

Heidari, Somaye,Mehri, Soghra,Shariaty, Vahidesadat,Hosseinzadeh, Hossein KOREAN PHARMACOPUNCTURE INSTITUTE 2018 Journal of pharmacopuncture Vol.21 No.1

Objective: D-galactose (D-gal) is well-known agent to induce aging process. In the present study, we selected crocin, the main constituent of Crocus sativus L. (saffron), against D-gal- induced cytotoxicity in human neuroblastoma SH-SY5Y cells. Methods: Pretreated cells with crocin ($25-500{\mu}M$, 24 h) were exposed to D-gal (25-400 mM, 48 h). The MTT assay was used for determination cell viability. Dichlorofluorescin diacetate assay (DCF-DA) and senescence associated ${\beta}$-galactosidase staining assay (SA-${\beta}$-gal) were used to evaluate the generation of reactive oxygen species and beta-galactosidase as an aging marker, respectively. Also advanced glycation end products (AGEs) expression which is known as the main mechanism of age-related diseases was measured by western blot analysis. Results: The findings of our study showed that treatment of cells with D-gal (25-400 mM) for 48h decreased cell viability concentration dependency. Reactive oxygen species (ROS) levels which are known as main factors in age-related diseases increased from $100{\pm}8%$ in control group to $132{\pm}22%$ in D-gal (200 mM) treated cells for 48h. The cytotoxic effects of D-gal decreased with 24h crocin pretreatment of cells. The cell viability at concentrations of $100{\mu}M$, $200{\mu}M$ and $500{\mu}M$ increased and ROS production decreased at concentrations of 200 and $500{\mu}M$ to $111.5{\pm}6%$ and $108{\pm}5%$, respectively. Also lysosomal biomarker of aging and carboxymethyl lysine (CML) expression as an AGE protein, significantly increased in D-gal 200 mM group after 48h incubation compare to control group. Pre-treatment of SHSY-5Y cells with crocin ($500{\mu}M$) before adding D-gal significantly reduced aging marker and CML formation. Conclusion: Treatment of SH-SY5Y cells with crocin before adding of D-gal restored aging effects of D-gal concentration dependency. These findings indicate that crocin has potent anti- aging effects through inhibition of AGEs and ROS production.

Molecular dynamics simulation of carbon molecular sieve preparation for air separation

Elham Yaghoobpour,ALI AHMADPOUR,Nafiseh Farhadian,Mojtaba Shariaty-Niassar 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.3

Carbon deposition process on activated carbon (AC) in order to produce carbon molecular sieve (CMS)was simulated using molecular dynamics simulation. The proposed activated carbon for simulation includes microporeswith different characteristic diameters and lengths. Three different temperatures of 773 K, 973 K, and 1,273 K wereselected to investigate the optimum deposition temperature. Simulation results show that the carbon deposition processat 973 K creates the best adsorbent structure. While at lower temperature some micropore openings are blockedwith carbon atoms, at higher temperature the number of deposited carbons on the micropores does not change significantly. Also, carbon deposition process confirms the pseudo-second-order kinetic model with an endothermic behavior. To evaluate the sieving property of adsorbent products, nitrogen and oxygen adsorption on the initial and finaladsorbent products are examined. Results show that there is not any considerable difference between the equilibriumadsorption amounts of nitrogen and oxygen on the initial and final adsorbents especially at low pressure (P<10 atm). Although, adsorption kinetics curves of these gases change significantly after the carbon deposition process in comparisonwith the initial sample. These observations indicate that the final adsorbent has high selectivity towards oxygencompared with the nitrogen, so it can be called a carbon molecular sieve. All simulated results are in good agreementwith experiments.

Preventive effects of crocin on neuronal damages induced by D-galactose through AGEs and oxidative stress in human neuroblastoma cells (SH-SY5Y)

Somaye Heidari,Soghra Mehri,Vahidesadat Shariaty,Hossein Hosseinzadeh 대한약침학회 2018 Journal of pharmacopuncture Vol.21 No.1

Objective: D-galactose (D-gal) is well-known agent to induce aging process. In the present study, we selected crocin, the main constituent of Crocus sativus L. (saffron), against D-gal- induced cytotoxicity in human neuroblastoma SH-SY5Y cells. Methods: Pretreated cells with crocin (25-500 μM, 24 h) were exposed to D-gal (25–400 mM, 48 h). The MTT assay was used for determination cell viability. Dichlorofluorescin diacetate assay (DCF-DA) and senescence associated β-galactosidase staining assay (SA- β-gal) were used to evaluate the generation of reactive oxygen species and beta-galactosidase as an aging marker, respectively. Also advanced glycation end products (AGEs) expression which is known as the main mechanism of age-related diseases was measured by western blot analysis. Results: The findings of our study showed that treatment of cells with D-gal (25-400 mM) for 48h decreased cell viability concentration dependency. Reactive oxygen species (ROS) levels which are known as main factors in age-related diseases increased from 100 ± 8% in control group to 132 ± 22% in D-gal (200 mM) treated cells for 48h. The cytotoxic effects of D-gal decreased with 24h crocin pretreatment of cells. The cell viability at concentrations of 100 μM, 200 μM and 500 μM increased and ROS production decreased at concentrations of 200 and 500 μM to 111.5 ± 6% and 108 ± 5%, respectively. Also lysosomal biomarker of aging and carboxymethyl lysine (CML) expression as an AGE protein, significantly increased in D-gal 200 mM group after 48h incubation compare to control group. Pretreatment of SHSY-5Y cells with crocin (500 μM) before adding D-gal significantly reduced aging marker and CML formation. Conclusion: Treatment of SH-SY5Y cells with crocin before adding of D-gal restored aging effects of D-gal concentration dependency. These findings indicate that crocin has potent anti- aging effects through inhibition of AGEs and ROS production.

On bending characteristics of smart magneto-electro-piezoelectric nanobeams system

Shariati, Ali,Ebrahimi, Farzad,Karimiasl, Mahsa,Selvamani, Rajendran,Toghroli, Ali Techno-Press 2020 Advances in nano research Vol.9 No.3

The content of this study focuses on bending of flexoelectric Magneto-Electro-Elastic (MEE) nanobeams inserted within the foundation of Winkler-Pasternak according to nonlocal elasticity theory. Applying Hamilton's principle, the nonlocal nanobeams' governing equations in the framework higher order refined beam theory are attained and resolved through adapting an analytical solution. A parametric research is demonstrated for studying the effects that magneto-electro-mechanical loadings, the nonlocal parameter, flexoelectric, as well as the aspect ratio all have on the deflection properties of nanobeams. A discovery lead to beam geometrical parameters, the boundary conditions, flexoelectricity and nonlocal parameter partake substantial effects on nanoscale beams' dimensionless deflection.

Investigating vibrational behavior of graphene sheets under linearly varying in-plane bending load based on the nonlocal strain gradient theory

Shariati, Ali,Barati, Mohammad Reza,Ebrahimi, Farzad,Singhal, Abhinav,Toghroli, Ali Techno-Press 2020 Advances in nano research Vol.8 No.4

A study that primarily focuses on nonlocal strain gradient plate model for the sole purpose of vibration examination, for graphene sheets under linearly variable in-plane mechanical loads. To study a better or more precise examination on graphene sheets, a new advance model was conducted which carries two scale parameters that happen to be related to the nonlocal as well as the strain gradient influences. Through the usage of two-variable shear deformation plate approach, that does not require the inclusion of shear correction factors, the graphene sheet is designed. Based on Hamilton's principle, fundamental expressions in regard to a nonlocal strain gradient graphene sheet on elastic half-space is originated. A Galerkin's technique is applied to resolve the fundamental expressions for distinct boundary conditions. Influence of distinct factors which can be in-plane loading, length scale parameter, load factor, elastic foundation, boundary conditions, and nonlocal parameter on vibration properties of the graphene sheets then undergo investigation.

Experimental and numerical investigations on the ratcheting characteristics of cylindrical shell under cyclic axial loading

Shariati, M.,Hatami, H.,Torabi, H.,Epakchi, H.R. Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.6

The ratcheting characteristics of cylindrical shell under cyclic axial loading are investigated. The specimens are subjected to stress-controlled cycling with non-zero mean stress, which causes the accumulation of plastic strain or ratcheting behavior in continuous cycles. Also, cylindrical shell shows softening behavior under symmetric axial strain-controlled loading and due to the localized buckling, which occurs in the compressive stress-strain curve of the shell; it has more residual plastic strain in comparison to the tensile stress-strain hysteresis curve. The numerical analysis was carried out by ABAQUS software using hardening models. The nonlinear isotropic/kinematic hardening model accurately simulates the ratcheting behavior of shell. Although hardening models are incapable of simulating the softening behavior of the shell, this model analyzes the softening behavior well. Moreover, the model calculates the residual plastic strain close to the experimental data. Experimental tests were performed using an INSTRON 8802 servo-hydraulic machine. Simulations show good agreement between numerical and experimental results. The results reveal that the rate of plastic strain accumulation increases for the first few cycles and then reduces in the subsequent cycles. This reduction is more rapid for numerical results in comparison to experiments.

Optimal Trajectory Planning of a Mobile Robot with Spatial Manipulator For Obstacle Avoidance

Shariati Nia Mostafa,Ghayour Mostafa,Mosayebi Masoud 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

Mobile robots consist of a mobile platform with one or many manipulators mounted on it are of great interest in a number of applications. Combination of platform and manipulator causes robot operates in extended work space. The analysis of these systems includes kinematics redundancy that makes more complicated problem. However, it gives more feasibility to robotic systems because of the existence of multiple solutions in a specified workspace. This paper presents a methodology in generating paths and trajectories for both the mobile platform and a 3DOF manipulator mounted on it, in the presence of obstacles. Obstacles add kinematics constraint into optimization problem. The method employs smooth and continuous functions such as polynomials. The proposed method includes obtaining time history of the mobile robot motion. It is supposed that the obstacles can be enclosed in cylinders. The platform has been used in this research is a differentially-driven platform. The core of the method is based on mapping the nonholonomic constraint to a space where it can be satisfied trivially. A suitable criterion can be used to solve an optimization problem to find the optimal solution. In this research, the problem of path planning with simultaneous optimization of kinematics and dynamic indices has been accomplished using genetic algorithm in order to find the global optimum solution. The validity of the methodology is demonstrated by using a differential-drive mobile manipulator system, various simulations of platform with a spatial 3-link manipulator are presented to show the effectiveness of the presented method.

Experimental investigation on the effect of cementitious materials on fresh and mechanical properties of self-consolidating concrete

Shariati, Mahdi,Rafie, Shervin,Zandi, Yousef,Fooladvand, Rouhollah,Gharehaghaj, Behnam,Mehrabi, Peyman,Shariat, Ali,Trung, Nguyen Thoi,Salih, Musab N.A.,Poi-Ngian, Shek Techno-Press 2019 Advances in concrete construction Vol.8 No.3

Although applying self-consolidating concrete (SCC) in many modern structures is an inevitable fact, the high consumption of cement in its mixing designs has led to increased production costs and adverse environmental effects. In order to find economically viable sources with environmentally friendly features, natural pozzolan pumice and blast furnace slag in 10-50% of replacement binary designs have been investigated for experiments on the properties of fresh concrete, mechanical properties, and durability. As a natural pozzolan, pumice does not require advanced equipment to prepare for consumption and only needs to be powdered. Pumice has been the main focus of this research because of simple preparation. Also to validate the results, in addition to the control specimens of each design, fly ash as a known powder has been evaluated. Moreover, ternary mixes of pumice and silica fume were investigated to enhance the obtained results of binary mixes. It was concluded that pumice and slag powders indicated favorable performance in the high percentage of replacement.

Investigation of microstructure and surface effects on vibrational characteristics of nanobeams based on nonlocal couple stress theory

Shariati, Ali,Barati, Mohammad Reza,Ebrahimi, Farzad,Toghroli, Ali Techno-Press 2020 Advances in nano research Vol.8 No.3

The article brings the study of nonlocal, surface and the couple stress together to apparent the frequency retaliation of FG nanobeams (Functionally graded). For the examination of frequency retaliation, the article considers the accurate spot of neutral axis. This article aims to enhance the coherence of proposed model to accurately encapsulate the significant effects of the nonlocal stress field, size effects together with material length scale parameters. These considered parameters are assimilated through what are referred to as modified couple stress as well as nonlocal elasticity theories, which encompasses the stiffness-hardening and softening influence on the nanobeams frequency characteristics. Power-law distribution is followed by the functional gradation of the material across the beam width in the considered structure of the article. Following the well-known Hamilton's principle, fundamental basic equations alongside their correlated boundary conditions are solved analytically. Validation of the study is also done with published result. Distinct parameters (such as surface energy, slenderness ratio, as nonlocal material length scale and power-law exponent) influence is depicted graphically following the boundary conditions on non-dimensional FG nanobeams frequency.